WO2022065244A1 - Parallel link mechanism and link operation device - Google Patents

Abstract

A parallel link mechanism in which a distal-end member can move over a spherical surface having a predetermined radius from a fixed rotation center comprises a proximal-end-side link hub (1), two link mechanisms (11), rotating bodies (2a, 2b), and a distal-end-side link hub (3). The rotating body (2a) is connected to one of the two link mechanisms (11). The rotating body (2a) is rotatably linked with the proximal-end-side link hub (1). In the link mechanisms (11), first center axes (15a, 15b) of first revolute pairs (25a, 25b) and second center axes (16a, 16b) of second revolute pairs (26a, 26b) intersect at a spherical link center point (30). The rotation center axis (12) of the rotating body (2a) intersects with the spherical link center point (30). The number of rotating bodies (2a, 2b) is less than the number of degrees of freedom of the orientation of the distal-end-side link hub (3).

Description

Parallel link mechanism and link activator

The present invention relates to a parallel link mechanism and a link actuating device.

Conventionally, a parallel link mechanism used for various devices such as medical devices and industrial devices is known (see, for example, Patent Document 1 and Patent Document 2).

Japanese Unexamined Patent Publication No. 2000-94245 Tokukai 2015-194207

The parallel link mechanism of Patent Document 1 has a relatively simple configuration, but the operating angle of each link is small. Therefore, if the operating range of the traveling plate is set large, there is a problem that the length of the link becomes long and the size of the entire mechanism becomes large, which leads to an increase in the size of the device. Therefore, it has been difficult to use it in applications that require a compact configuration and a precise and wide operating range.

The link actuating device of Patent Document 2 has a configuration in which a link hub on the proximal end side and a link hub on the distal end side are connected via three or more sets of link mechanisms in a four-node chain. The link actuating device of Patent Document 2 is compact, yet can operate with a precise and wide operating range.

However, in the link actuating device of Patent Document 2, the link hub on the tip side operates with two degrees of freedom of rotation with respect to the drive source for attitude control provided in three or more sets of link mechanisms. Therefore, in order to add more degrees of freedom of rotation, a mechanism for rotating the entire device is required outside the link actuating device. As a result, there is a problem that the entire device becomes large. Further, due to the structure, the radius of gyration of the link hub on the tip side changes according to the bending angle of the link mechanism, and the position of the center of rotation in the rotational movement of the link hub on the tip side cannot be fixed. That is, since the link hub on the tip side cannot move on a spherical surface having a certain radius from the fixed center of rotation when viewed from the link hub on the base end side, there is a problem that it is difficult to imagine the operation of the link hub on the tip side. rice field.

An object of the present invention is to provide a parallel link mechanism and a link actuating device in which the tip member can move on a spherical surface having a constant radius from a fixed center of rotation, and which is compact, low cost, and has a high degree of freedom of rotation. That is.

The parallel link mechanism according to the present disclosure includes a base end side link hub, two or more link mechanisms, two or more driveable rotating bodies, and a front end side link hub. The two or more rotating bodies are connected to at least one link mechanism of the two or more link mechanisms. Two or more rotating bodies are rotatably connected to the base end side link hub. Each of the two or more linkages includes a first link member and a second link member. The second link member is rotatably connected to the first link member at the first rotational pair even portion. The second link member is rotatably connected to the tip end side link hub at the second rotational pair even portion. The first link member is fixed to two or more rotating bodies. In two or more link mechanisms, the first central axis of the first rotational pair even portion and the second central axis of the second rotational pair even portion intersect at the spherical link center point. The rotation center axes of two or more rotating bodies intersect the spherical link center points. The number of two or more rotating bodies is less than the number of degrees of freedom in the posture of the tip side link hub.

The link actuating device according to the present disclosure includes the above-mentioned parallel link mechanism and a drive source for attitude control. The attitude control drive source rotates two or more rotating bodies, and arbitrarily changes the attitude of the tip side link hub with respect to the base end side link hub.

According to the above, a parallel link mechanism and a link actuating device can be obtained, in which the tip member can move on a spherical surface having a certain radius from a fixed center of rotation, and which is compact, low cost, and has a high degree of freedom of rotation.

It is a perspective schematic diagram which shows the structure of the parallel link mechanism which concerns on Embodiment 1. FIG. It is a front schematic diagram of the parallel link mechanism shown in FIG. It is a partial schematic diagram of the front end side link hub and the link mechanism seen from the direction along the arrow 60 of FIG. FIG. 3 is a schematic cross-sectional view taken along the line segment IV-IV of FIG. It is a perspective schematic diagram for demonstrating the operation of the parallel link mechanism shown in FIG. It is a perspective schematic diagram for demonstrating the operation of the parallel link mechanism shown in FIG. FIG. 6 is a schematic top view of the parallel link mechanism shown in FIG. It is a perspective schematic diagram which shows the structure of the parallel link mechanism which concerns on Embodiment 2. It is a front schematic diagram of the parallel link mechanism shown in FIG. It is a partial schematic diagram of the front end side link hub and the link mechanism seen from the direction along the arrow 60 of FIG. FIG. 3 is a schematic cross-sectional view taken along the line segment XI-XI of FIG. It is a perspective schematic diagram for demonstrating the operation of the parallel link mechanism shown in FIG. It is a perspective schematic diagram for demonstrating the operation of the parallel link mechanism shown in FIG. FIG. 3 is a schematic top view of the parallel link mechanism shown in FIG. It is a front schematic diagram which shows the modification of the parallel link mechanism which concerns on Embodiment 2. It is a perspective schematic diagram which shows the structure of the parallel link mechanism which concerns on Embodiment 3. FIG. It is a partial cross-sectional schematic diagram which shows the structure of the parallel link mechanism which concerns on Embodiment 4. FIG. It is a schematic diagram which shows the structure of the parallel link mechanism which concerns on Embodiment 5. FIG. 3 is an enlarged schematic cross-sectional view of region XIX in FIG. It is a perspective schematic diagram which shows the structure of the parallel link mechanism which concerns on Embodiment 6. It is a front schematic diagram of the parallel link mechanism shown in FIG. FIG. 2 is a schematic cross-sectional view taken along the line segment XXII-XXII of FIG. 21. It is a schematic top view of the rotating body of the parallel link mechanism shown in FIG. It is a perspective schematic diagram which shows the structure of the link actuating apparatus which concerns on Embodiment 7. It is a schematic diagram which shows the structure of the link actuating apparatus shown in FIG. 24. It is a schematic diagram which shows the 1st modification of the link actuating apparatus which concerns on Embodiment 7. It is a schematic diagram which shows the 2nd modification of the link actuating apparatus which concerns on Embodiment 7. It is a perspective schematic diagram which shows the 3rd modification of the link actuating apparatus which concerns on Embodiment 7. It is a perspective schematic diagram which shows the structure of the link actuating apparatus which concerns on Embodiment 8. It is a schematic diagram which shows the structure of the link actuating apparatus shown in FIG. FIG. 3 is an enlarged schematic cross-sectional view of region XXXI in FIG. FIG. 3 is a schematic cross-sectional view taken along the line segment XXXII-XXXII of FIG. 30. It is a schematic diagram which shows the 1st modification of the link actuating apparatus which concerns on Embodiment 8. It is a schematic diagram which shows the structure of the link actuating apparatus shown in FIG. 33. FIG. 3 is an enlarged schematic cross-sectional view of the region XXXV of FIG. 34. FIG. 3 is a schematic cross-sectional view taken along the line segment XXXVI-XXXVI of FIG. 34. It is a perspective schematic diagram which shows the 2nd modification of the link actuating apparatus which concerns on Embodiment 8. It is a schematic diagram which shows the 3rd modification of the link actuating apparatus which concerns on Embodiment 8. It is a schematic diagram which shows the structure of the parallel link mechanism which concerns on Embodiment 9. It is a schematic diagram which shows the structure of the link actuating apparatus which concerns on Embodiment 10.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are given the same reference numbers, and the description thereof will not be repeated.

(Embodiment 1)
<Configuration of parallel link mechanism>
FIG. 1 is a schematic perspective view showing the configuration of the parallel link mechanism according to the first embodiment. FIG. 2 is a front schematic view of the parallel link mechanism shown in FIG. FIG. 3 is a partial schematic view of the front end side link hub and the link mechanism seen from the direction along the arrow 60 of FIG. FIG. 4 is a schematic cross-sectional view of the line segment IV-IV of FIG.

The parallel link mechanisms shown in FIGS. 1 to 4 include a base end side link hub 1, three link mechanisms 11, two driveable rotating bodies 2a and 2b, a driven rotating body 2z, and a tip side link hub. 3 and. The base end side link hub 1 is a disk-shaped member. The planar shape of the base end side link hub 1 shown in FIG. 1 is a circular shape, but the planar shape is a polygonal shape such as a triangle shape or a quadrangular shape, or any other shape such as an elliptical shape or a semicircular shape. May be. Further, the base end side link hub 1 may have a plate-like body as shown in FIG. 1, but may have any other shape, or may be a part of another mechanical device. Further, the number of the link mechanisms 11 may be 3 or more, and may be 4 or 5, for example. The number of rotating bodies 2a and 2b may be 1 or more.

The two rotating bodies 2a and 2b are rotatably connected to the base end side link hub 1 in a state where the respective rotation center axes 12 are laminated so as to coincide with each other. The two rotating bodies 2a and 2b are connected to the base end side link hub 1 by bolts 7 and nuts 8 as fixing members. A hole is formed in the center of the two rotating bodies 2a and 2b for passing the bolt 7. A washer 9 is arranged between the head located at the end of the bolt 7 and the rotating body 2a. Rotational resistance reducing members 19 are arranged between the two stacked rotating bodies 2a and 2b, respectively. The two rotating bodies 2a and 2b can be driven, that is, they can rotate or move by themselves. In order to enable the rotating bodies 2a and 2b to be driven around the rotation center axis 12, a motor (not shown) may be incorporated in the rotating bodies 2a and 2b, although not shown in FIG. Alternatively, the entire rotating bodies 2a and 2b may be configured as a motor. Such a motor is a so-called direct drive system because the rotational force is transmitted to the drive target (rotating bodies 2a, 2b). If a direct drive type motor is used, the capacity of the drive source can be reduced. Further, if the motor is a hollow direct drive type motor, wiring can be built in the hollow portion, so that the capacity of the entire device can be reduced.

On the other hand, the driven rotating body 2z cannot be driven like the rotating bodies 2a and 2b, and does not have a built-in motor or the like. The driven rotating body 2z is a so-called driven rotating body that moves following other members such as the driving rotating bodies 2a and 2b, or moves by a method other than the driving source. In this sense, the driven rotating body 2z is distinguished from the rotating bodies 2a and 2b. In each figure, the driven rotating body 2z has a hole formed in the center thereof for passing the bolt 7 like the rotating bodies 2a and 2b. As a result, the driven rotating body 2z may rotate so as to follow the rotational driving of the rotating bodies 2a and 2b. Alternatively, by a method other than the above, the driven rotating body 2z may be drivenly rotated by a mechanism different from that of the rotating bodies 2a and 2b.

Of the two stacked rotating bodies 2a and 2b and the driven rotating body 2z, the driven rotating body 2z located on the base end side link hub 1 side and the base end side link hub 1 are also rotation resistance reducing members. 19 is arranged.

The two rotating bodies 2a and 2b and the driven rotating body 2z have a substantially circular planar shape. The two rotating bodies 2a and 2b and the driven rotating body 2z each have a protruding portion formed on the outer peripheral portion thereof for connecting the link mechanism 11. The protruding portion is a convex portion protruding outward from the outer peripheral end faces of the rotating bodies 2a and 2b and the driven rotating body 2z. A total of three rotating bodies 2a and 2b and a driven rotating body 2z are connected to each of the three link mechanisms 11 at the protruding portion.

Each of the three link mechanisms 11 includes a first link member 4a to 4c and a second link member 6a to 6c. The first first link member 4a is fixed to the protruding portion of the rotating body 2a. The second first link member 4b is fixed to the protruding portion of the rotating body 2b. The third first link member 4c is fixed to the protruding portion of the driven rotating body 2z. Any method can be used as a method of fixing the first link members 4a to 4c to the protruding portions of the rotating bodies 2a and 2b and the driven rotating body 2z. For example, the first link members 4a to 4c may be fixed to the rotating bodies 2a and 2b and the driven rotating body 2z by screws 56 as fixing members. Alternatively, the first link members 4a to 4c may be fixed by welding to the rotating bodies 2a and 2b and the driven rotating body 2z, or may be fixed via an adhesive layer.

The first link members 4a to 4c have a columnar shape having a bent portion. The lengths of the first link members 4a to 4c are different from each other. The first link member 4c connected to the driven rotating body 2z arranged at the position closest to the proximal end side link hub 1 is the longest. Further, the first link member 4a connected to the rotating body 2a arranged farthest from the proximal end side link hub 1 is the shortest. The first link members 4a to 4c have a first portion extending in a direction perpendicular to the surfaces of the rotating bodies 2a and 2b and the driven rotating body 2z, a second portion extending diagonally with respect to the extending direction of the first portion, and a second portion. The bent portion, which is a connecting portion between the first portion and the second portion, is included. As shown in FIG. 2, one end of the first portion of the first link members 4a to 4c is fixed to the rotating bodies 2a and 2b and the driven rotating body 2z. The other end of the first portion opposite to the one end is connected to one end of the second portion. In the second portion, the other end portion on the opposite side to the one end portion is rotatably connected to the second link members 6a to 6c, respectively. The second portion is configured to be gradually separated from the rotation center axis 12 of the rotating bodies 2a and 2b and the driven rotating body 2z from one end to the other. That is, the extending direction of the second portion of the first link members 4a to 4c is inclined with respect to the rotation center axis 12.

The first second link member 6a is rotatably connected to the first link member 4a at the first rotation paired pair portion 25a. The second second link member 6b is rotatably connected to the first link member 4b at the first rotation paired pair portion 25b. The third second link member 6c is rotatably connected to the first link member 4c at the first rotational pair 25c. The first rotation paired portions 25a to 25c each have a first central axis 15a to 15c. The first central shafts 15a to 15c extend in the direction toward the rotation central shaft 12. Further, the first central axes 15a to 15c are inclined with respect to the rotation central axis 12 so as to be separated from the rotating bodies 2a and 2b and the driven rotating body 2z as they approach the rotation center axis 12.

The structure of the first rotation paired pair portions 25a to 25c can have any configuration. For example, the first rotation paired portions 25a to 25c include a shaft portion extending along the first central shaft 15a to 15c and a portion of the first link member 4a to 4c in which a through hole into which the shaft portion is inserted is formed. , The shaft portion may be formed by the portion of the second link member 6a to 6b in which the through hole is formed. In this case, the first link members 4a to 4c and the second link members 6a to 6c are rotatable around the shaft portion. In order to prevent the shaft portion from coming off from the through holes of the first link members 4a to 4c and the second link members 6a to 6c, for example, nuts as positioning members may be fixed to both ends of the shaft portion.

Alternatively, the shaft portion is connected to either one of the first link members 4a to 4c and the second link members 6a to 6c, and the shaft portion is connected to any one of the first link members 4a to 4c and the second link members 6a to 6c. It may be in a state of being inserted into a through hole formed in either one or the other. Either one of the first link members 4a to 4c and the second link members 6a to 6c may be rotatable with respect to the shaft portion. A nut or the like as a positioning member for preventing the shaft portion from coming off from the through hole may be fixed to the tip end portion of the shaft portion.

The second link members 6a to 6c have a first portion extending in a direction intersecting the extending direction of the first central shaft 15a to 15c, and a first portion extending from the tip end portion of the first portion along the first central shaft 15a to 15c. Includes 2 parts. The root portion of the first portion opposite to the tip portion thereof is a part of the first rotary paired portions 25a to 25c rotatably connected to the first link members 4a to 4c.

The second link members 6a to 6c are rotatably connected to the tip end side link hub 3 at the second rotary paired pair portions 26a to 26c. The second rotation paired portions 26a to 26c each have a second central axis 16a to 16c. Specifically, the second rotation paired portions 26a to 26c are a shaft portion extending along the second central shaft 16a to 16c and a protruding portion of the tip side link hub 3 in which a through hole for inserting the shaft portion is formed. And a pair of wall portions arranged so as to sandwich the protruding portion and having through holes for inserting the shaft portion. The pair of wall portions are formed at the tip portions of the second portions of the second link members 6a to 6c. The shaft portion is composed of a bolt 17 and a nut 18. The protruding portion of the link hub 3 on the distal end side and the second link members 6a to 6c are rotatable around the shaft portion. As shown in FIG. 3, a rotation resistance reducing member 29 is arranged between the pair of wall portions and the protruding portion of the tip side link hub 3. As the rotation resistance reducing member 29, any member capable of reducing the coefficient of friction between the pair of wall portions and the protrusions described above can be used. For example, as the rotation resistance reducing member 29, a resin shim washer or the like having a lower coefficient of friction can be used.

The second central shafts 16a to 16c extend in a direction different from that of the first central shafts 15a to 15c, and extend in the directions toward the rotating central shafts 12 of the rotating bodies 2a and 2b and the driven rotating body 2z. The second central axes 16a to 16c extend in a direction orthogonal to, for example, the rotation central axis 12 of the rotating bodies 2a and 2b and the driven rotating body 2z.

In the three link mechanisms 11, the first central axes 15a to 15c of the first rotation paired portions 25a to 25c and the second central axes 16a to 16c of the second rotating paired portions 26a to 26c intersect at the spherical link center point 30. .. The rotation center axis 12 of the three or more rotating bodies 2a and 2b and the driven rotating body 2z intersects the spherical link center point 30. If the above relationship is satisfied, the arrangement of the first rotation paired pair portion 25a to 25c and the second rotation paired pair portion 26a to 26c can be arbitrarily changed. As can be seen from FIG. 3, in each of the three second link members 6a to 6c, the first central axis 15a to 15c and the second central axis 16a to 16c when viewed from the tip side link hub 3 side (hereinafter, plan view). The angle between them is substantially 90 °. Further, the first central axes 15a to 15c are arranged at equal intervals in the circumferential direction about the spherical link center point 30. Each of the parallel link mechanisms of the present embodiment is arranged so that all the central axes of each rotational pair and the central axis of rotation of each rotating body intersect at one point (spherical link center point 30). The arrangement of the link mechanism 11 may be changed.

The planar shape of the tip side link hub 3 is a hexagonal shape, but it may be any other polygonal shape. The planar shape may be any shape such as a circular shape or an elliptical shape.

The three link mechanisms 11 are arranged at equal intervals on the circumference in a plan view. That is, with respect to the first central axes 15a to 15c, the angle formed by the two adjacent first central axes when viewed from the spherical link center point 30 in a plan view is 120 °. Further, with respect to the second central axes 16a to 16c, the angle formed by the two adjacent second central axes when viewed from the spherical link center point 30 in a plan view is 120 °. The three link mechanisms 11 may be arranged on the circumference at different intervals in a plan view.

<Operation of parallel link mechanism>
FIG. 5 is a schematic perspective view for explaining the operation of the parallel link mechanism shown in FIG. FIG. 6 is a schematic perspective view for explaining the operation of the parallel link mechanism shown in FIG. FIG. 7 is a schematic top view of the parallel link mechanism shown in FIG.

As shown in FIG. 5, the posture of the tip side link hub 3 is maintained by rotating all the rotating bodies 2a and 2b (and the driven rotating body 2z) in the same direction and by the same angle as shown by the arrows in FIG. The tip side link hub 3 can be rotated about the rotation center axis 12 (see FIG. 2) while keeping the state. At this time, at least the relative positional relationship between the protrusions of the rotating bodies 2a and 2b (and the driven rotating body 2z) is maintained.

Further, as shown in FIG. 6, by making the rotation directions and rotation angles of the three rotating bodies 2a and 2b and the driven rotating body 2z different, the posture of the tip side link hub 3 with respect to the base end side link hub 1 can be arbitrarily set. Can be changed. That is, by controlling the rotation angles of the two rotating bodies 2a and 2b (and the driven rotating body 2z), the bending angle θ1, the turning angle θ2 and the rotation in the posture of the tip side link hub 3 as seen from the spherical link center point 30. You can control the angle. That is, the posture of the tip side link hub 3 has three degrees of freedom: a bending angle θ1, a turning angle θ2, and a rotation angle.

Here, as shown in FIG. 6, the bending angle θ1 is a rotation with the tip side link hub central axis 31 which is a straight line perpendicular to all of the second central axes 16a to 16c and passing through the spherical link center point 30. It is an angle formed by the body 2a, 2b and the driven rotating body 2z with the rotation center axis 12. As shown in FIG. 7, the turning angle θ2 is a straight line obtained by projecting the tip side link hub central axis 31 onto a plane (XY plane) that passes through the spherical link center point 30 and vertically intersects the rotation center axis 12, and XY. It is an angle formed by the X-axis set with the spherical link center point 30 as the origin in the plane. The rotation angle is a rotation angle when the tip end side link hub 3 rotates with respect to the base end side link hub 1 about the rotation center axis 12 as shown by an arrow in FIG.

In the present embodiment, among the three rotating bodies, the rotating body that can be driven (it is possible to rotate by itself instead of moving along with the movement of other members) is, for example, 2 of rotating bodies 2a and 2b. There is only one. On the other hand, the posture of the tip side link hub 3 has three degrees of freedom. That is, the number (two) of the driveable rotating bodies 2a and 2b is smaller than the number of degrees of freedom (3) in the posture of the tip side link hub 3. As the driven rotating body 2z is driven by another drive source or method, for example, the first link member 4c and the second link member 6c among the three link mechanisms 11 are, for example, the first link members 4a, 4b and the first. 2 Follows the drive of the link members 6a and 6b.

<Action effect>
The parallel link mechanism according to the present disclosure includes a proximal end side link hub 1, three or more link mechanisms 11, three or more rotating bodies 2a, 2b, a driven rotating body 2z, and a tip end side link hub 3. Be prepared. The three or more rotating bodies 2a and 2b and the driven rotating body 2z are connected to each of the three or more link mechanisms 11. The three or more rotating bodies 2a and 2b and the driven rotating body 2z are rotatably connected to the base end side link hub 1 in a state of being laminated so that their respective rotation center axes 12 coincide with each other. Each of the three or more link mechanisms 11 includes first link members 4a to 4c and second link members 6a to 6c. The first link members 4a to 4c are fixed to one of three or more rotating bodies 2a and 2b and a driven rotating body 2z. The second link members 6a to 6c are rotatably connected to the first link members 4a to 4c at the first rotation paired pair portions 25a to 25c. The second link members 6a to 6c are rotatably connected to the distal end side link hub 3 at the second rotary paired pair portions 26a to 26c. In the three or more link mechanisms 11, the first central axes 15a to 15c of the first rotation paired portions 25a to 25c and the second central axes 16a to 16c of the second rotating paired portions 26a to 26c are spherical link center points 30. Meet at. The rotation center axis 12 of the three or more rotating bodies 2a and 2b and the driven rotating body 2z intersects the spherical link center point 30. Of the three or more rotating bodies 2a and 2b and the driven rotating body 2z, the number of driveable rotating bodies 2a and 2b (2) is smaller than the number of degrees of freedom in the posture of the tip side link hub 3 (3). ..

By doing so, the tip side link hub 3 can be operated with three degrees of freedom of rotation with respect to the base end side link hub 1. That is, by rotating the three rotating bodies 2a and 2b and the driven rotating body 2z, the tip side link hub 3 is moved along the spherical surface centered on the spherical link center point 30 with respect to the base end side link hub 1. At the same time, the tip side link hub 3 can be rotated around the rotation center axis 12. Further, since the posture of the tip side link hub 3 is controlled by the rotational movement of the rotating bodies 2a and 2b and the driven rotating body 2z, a compact link operating device using the parallel link mechanism can be realized. Further, since the tip side link hub 3 moves along the spherical surface centered on the spherical link center point 30, it is easy to imagine the operation of the tip side link hub 3.

After diligent research, the inventor of this case found that the number of driveable rotating bodies can be made smaller than the number of degrees of freedom of the tip-side link hub. Specifically, as in the present embodiment, there are a total of three rotating bodies including the driven rotating body 2z, but only two of them can function as a driveable motor (rotating bodies 2a and 2b). ).

Normally, in order to set the number of degrees of freedom in the posture of the front end side link hub 3 to 3, it is considered that three rotating bodies as drive sources, which have the same number of degrees of freedom as the number of degrees of freedom, are required. However, for example, by synchronizing the drive of the motors of the two rotating bodies 2a and 2b with the other driven rotating body 2z, the driven rotating body 2z can also rotate. This is based on the finding that the drive of one rotating body affects the operation of multiple mechanisms. As a result, in addition to the above-mentioned bending angle and turning angle, the entire rotation angle can be freely controlled in order to determine the posture of the tip side link hub 3. Therefore, in the present embodiment, the posture of the front end side link hub 3 has three degrees of freedom, and the link mechanism 11 has three degrees of freedom.

(Embodiment 2)
<Configuration of parallel link mechanism>
FIG. 8 is a schematic perspective view showing the configuration of the parallel link mechanism according to the second embodiment. FIG. 9 is a front schematic view of the parallel link mechanism shown in FIG. FIG. 10 is a partial schematic view of the front end side link hub and the link mechanism seen from the direction along the arrow 60 of FIG. FIG. 11 is a schematic cross-sectional view of the line segment XI-XI of FIG.

The parallel link mechanism shown in FIGS. 8 to 11 includes a base end side link hub 1, two link mechanisms 11, two rotating bodies 2a and 2b, and a tip end side link hub 3. The base end side link hub 1 is a disk-shaped member. The planar shape of the base end side link hub 1 shown in FIG. 8 is a circular shape, but the planar shape is a polygonal shape such as a triangle shape or a quadrangular shape, or any other shape such as an elliptical shape or a semicircular shape. May be. Further, the base end side link hub 1 may have a plate-like body as shown in FIG. 8, but may have any other shape, or may be a part of another mechanical device.

The two rotating bodies 2a and 2b are rotatably connected to the base end side link hub 1 in a state where the respective rotation center axes 12 are laminated so as to coincide with each other. The two rotating bodies 2a and 2b are connected to the base end side link hub 1 by bolts 7 and nuts 8 as fixing members. A hole is formed in the center of the two rotating bodies 2a and 2b for passing the bolt 7. A washer 9 is arranged between the head located at the end of the bolt 7 and the rotating body 2a. Rotational resistance reducing members 19 are arranged between the two stacked rotating bodies 2a and 2b, respectively. The two rotating bodies 2a and 2b can be driven, that is, they can rotate or move by themselves. In order to enable the rotating bodies 2a and 2b to be driven around the rotation center axis 12, a motor (not shown) may be incorporated in the rotating bodies 2a and 2b, although not shown in FIG. Alternatively, the entire rotating bodies 2a and 2b may be configured as a motor. Such a motor is a so-called direct drive system because the rotational force is transmitted to the drive target (rotating bodies 2a, 2b). If a direct drive type motor is used, the capacity of the drive source can be reduced. Further, if the motor is a hollow direct drive type motor, wiring can be built in the hollow portion, so that the capacity of the entire device can be reduced. Further, the rotation resistance reducing member 19 is also arranged between the rotating body 2b located on the proximal end side link hub 1 side and the proximal end side link hub 1 among the two laminated rotating bodies 2a and 2b.

The plane shape of the two rotating bodies 2a and 2b is almost circular. Each of the two rotating bodies 2a and 2b has a protruding portion formed on the outer peripheral portion thereof for connecting the link mechanism 11. The protruding portion is a convex portion protruding outward from the outer peripheral end faces of the rotating bodies 2a and 2b. The two rotating bodies 2a and 2b are connected to each of the two link mechanisms 11 at the protrusion.

Each of the two link mechanisms 11 includes a first link member 4a, 4b and a second link member 6a, 6b. The first first link member 4a is fixed to the protruding portion of the rotating body 2a. The second first link member 4b is fixed to the protruding portion of the rotating body 2b. Any method can be used as a method of fixing the first link members 4a and 4b to the protruding portions of the rotating bodies 2a and 2b. For example, the first link members 4a and 4b may be fixed to the rotating bodies 2a and 2b by screws 56 as fixing members. Alternatively, the first link members 4a and 4b may be fixed by welding to the protruding portions of the rotating bodies 2a and 2b, or may be fixed via an adhesive layer.

The first link members 4a and 4b have a columnar shape having a bent portion. The lengths of the first link members 4a and 4b are different from each other. The first link member 4b connected to the rotating body 2b arranged at a position close to the proximal end side link hub 1 is long, and the first link connected to the rotating body 2a arranged far from the proximal end side link hub 1. The member 4a is short. The first link members 4a and 4b have a first portion extending in a direction perpendicular to the surface of the rotating bodies 2a and 2b, a second portion extending diagonally with respect to the extending direction of the first portion, and a first portion and a second portion. The bent portion, which is a connecting portion with the portion, is included. As shown in FIG. 9, one end of the first portion of the first link members 4a and 4b is fixed to the rotating bodies 2a and 2b. The other end of the first portion opposite to the one end is connected to one end of the second portion. In the second portion, the other end portion on the opposite side to the one end portion is rotatably connected to the second link members 6a and 6b, respectively. The second portion is configured to be gradually separated from the rotation center axis 12 of the rotating bodies 2a and 2b from one end to the other. That is, the extending direction of the second portion of the first link members 4a and 4b is inclined with respect to the rotation center axis 12.

The first second link member 6a is rotatably connected to the first link member 4a at the first rotation paired pair portion 25a. The second second link member 6b is rotatably connected to the first link member 4b at the first rotation paired pair portion 25b. The first rotation paired portions 25a and 25b have first central axes 15a and 15b, respectively. The first central axes 15a and 15b extend in the direction toward the rotation central axis 12 of the rotating bodies 2a and 2b. Further, the first central axes 15a and 15b are inclined with respect to the rotation central axis 12 so as to be separated from the rotating bodies 2a and 2b as they approach the rotation center axis 12.

The structure of the first rotation paired pair portions 25a and 25b can have any configuration. For example, the first rotation paired portions 25a and 25b include a shaft portion extending along the first central shafts 15a and 15b and a portion of the first link member 4a and 4b in which a through hole into which the shaft portion is inserted is formed. , It may be composed of the portion of the second link member 6a, 6b in which the through hole into which the shaft portion is inserted is formed. In this case, the first link members 4a and 4b and the second link members 6a and 6b are rotatable around the shaft portion. In order to prevent the shaft portion from coming off from the through holes of the first link members 4a and 4b and the second link members 6a and 6b, for example, nuts as positioning members may be fixed to both ends of the shaft portion.

Alternatively, the shaft portion is connected to either one of the first link members 4a and 4b and the second link members 6a and 6b, and the shaft portion is connected to any one of the first link members 4a and 4b and the second link members 6a and 6b. It may be in a state of being inserted into a through hole formed in either one or the other. Either one of the first link members 4a and 4b and the second link members 6a and 6b may be rotatable with respect to the shaft portion. A nut or the like as a positioning member for preventing the shaft portion from coming off from the through hole may be fixed to the tip end portion of the shaft portion.

The second link members 6a and 6b have a first portion extending in a direction intersecting the extending direction of the first central shafts 15a and 15b, and a second portion extending along the first central shafts 15a and 15b from the tip end portion of the first portion. Includes 2 parts. The root portion of the first portion on the opposite side to the tip portion is a part of the first rotary paired portions 25a and 25b rotatably connected to the first link members 4a and 4b.

The second link members 6a and 6b are rotatably connected to the tip end side link hub 3 at the second rotary paired pair portions 26a and 26b. The second rotation paired portions 26a and 26b have second central axes 16a and 16b, respectively. Specifically, the second rotation paired portions 26a and 26b are a shaft portion extending along the second central shafts 16a and 16b and a protruding portion of the tip side link hub 3 in which a through hole for inserting the shaft portion is formed. And a pair of wall portions arranged so as to sandwich the protruding portion and having through holes for inserting the shaft portion. The pair of wall portions are formed at the tip portions of the second portions of the second link members 6a and 6b. The shaft portion is composed of a bolt 17 and a nut 18. The protruding portion of the link hub 3 on the distal end side and the second link members 6a and 6b are rotatable around the shaft portion. As shown in FIG. 10, a rotation resistance reducing member 29 is arranged between the pair of wall portions and the protruding portion of the tip side link hub 3. As the rotation resistance reducing member 29, any member capable of reducing the coefficient of friction between the pair of wall portions and the protrusions described above can be used. For example, as the rotation resistance reducing member 29, a resin shim washer or the like having a lower coefficient of friction can be used.

The second central shafts 16a and 16b extend in a direction different from that of the first central shafts 15a and 15b, and extend in a direction toward the rotation central shaft 12 of the rotating bodies 2a and 2b. The second central axes 16a and 16b extend in a direction orthogonal to, for example, the rotation central axes 12 of the rotating bodies 2a and 2b.

In the two link mechanisms 11, the first central axes 15a and 15b of the first rotation paired portions 25a and 25b and the second central axes 16a and 16b of the second rotating paired portions 26a and 26b intersect at the spherical link center point 30. .. The rotation center axis 12 of the two rotating bodies 2a and 2b intersects the spherical link center point 30. If the above relationship is satisfied, the arrangement of the first rotation paired pair portions 25a and 25b and the second rotation paired pair portion 26a and 26b can be arbitrarily changed. As can be seen from FIG. 10, in each of the two second link members 6a and 6b, the first central shafts 15a and 15b and the second central shafts 16a and 16b when viewed from the tip side link hub 3 side (hereinafter referred to as plan view). The angle between them is substantially 90 °. Further, the first central axes 15a and 15b are arranged at equal intervals in the circumferential direction about the spherical link center point 30. Each of the parallel link mechanisms of the present embodiment is arranged so that all the central axes of each rotational pair and the central axis of rotation of each rotating body intersect at one point (spherical link center point 30). The arrangement of the link mechanism 11 may be changed.

The planar shape of the tip side link hub 3 is a hexagonal shape, but it may be any other polygonal shape. The planar shape may be any shape such as a circular shape or an elliptical shape.

With respect to the first central axes 15a and 15b, the angle formed by two adjacent first central axes when viewed from the spherical link center point 30 in a plan view is 120 °. Further, with respect to the second central axes 16a and 16b, the angle formed by the two adjacent second central axes when viewed from the spherical link center point 30 in a plan view is 120 °. The two link mechanisms 11 may be arranged on the circumference at intervals different from 120 ° in a plan view.

<Operation of parallel link mechanism>
FIG. 12 is a schematic perspective view for explaining the operation of the parallel link mechanism shown in FIG. FIG. 13 is a schematic perspective view for explaining the operation of the parallel link mechanism shown in FIG. FIG. 14 is a schematic top view of the parallel link mechanism shown in FIG.

As shown in FIG. 12, by rotating the two rotating bodies 2a and 2b in the same direction and by the same angle as shown by the arrow in FIG. 12, the tip side link hub 3 maintains the posture of the tip side link hub 3. Can be rotated around the rotation center axis 12 (see FIG. 9). At this time, the relative positional relationship between the protruding portions of the rotating bodies 2a and 2b is maintained.

Further, as shown in FIG. 13, the posture of the tip side link hub 3 with respect to the base end side link hub 1 can be arbitrarily changed by making the rotation directions and rotation angles of the two rotating bodies 2a and 2b different. That is, by controlling the rotation angles of the two rotating bodies 2a and 2b, it is possible to control the bending angle θ1, the turning angle θ2, and the rotation angle in the posture of the tip side link hub 3 as seen from the spherical link center point 30. That is, the posture of the tip side link hub 3 has three degrees of freedom: a bending angle θ1, a turning angle θ2, and a rotation angle.

Here, as shown in FIG. 13, the bending angle θ1 is a straight line perpendicular to the second central axes 16a and 16b and passing through the spherical link center point 30, the tip side link hub central axis 31 and the rotating body 2a. , 2b is the angle formed by the rotation center axis 12. As shown in FIG. 14, the turning angle θ2 is a straight line obtained by projecting the tip side link hub central axis 31 onto a plane (XY plane) that passes through the spherical link center point 30 and vertically intersects the rotation center axis 12, and XY. It is an angle formed by the X-axis set with the spherical link center point 30 as the origin in the plane. The rotation angle is a rotation angle when the tip end side link hub 3 rotates with respect to the base end side link hub 1 about the rotation center axis 12 as shown by an arrow in FIG.

In the present embodiment, both of the two rotating bodies 2a and 2b can be driven (all). Further, each of the link members constituting the two link mechanisms 11 can be driven. In the present specification, in each of the embodiments described thereafter, basically all the rotating bodies constituting the parallel link mechanism (link actuating device) can be driven as in the present embodiment.

<Action effect>
The parallel link mechanism according to the present disclosure includes a proximal end side link hub 1, two or more (two) link mechanisms 11, two or more (two) rotating bodies 2a and 2b, and a tip end side link hub. 3 and. The two rotating bodies 2a and 2b are connected to each of the above two link mechanisms 11. The two rotating bodies 2a and 2b are rotatably connected to the base end side link hub 1. Each of the two or more link mechanisms 11 includes a first link member 4a, 4b and a second link member 6a, 6b. The first link members 4a and 4b are fixed to one of the two rotating bodies 2a and 2b. The second link members 6a and 6b are rotatably connected to the first link members 4a and 4b at the first rotation paired pair portions 25a and 25b. The second link members 6a and 6b are rotatably connected to the tip end side link hub 3 at the second rotary paired pair portions 26a and 26b. In the two link mechanisms 11, the first central axes 15a and 15b of the first rotation paired portions 25a and 25b and the second central axes 16a and 16b of the second rotating paired portions 26a and 26b intersect at the spherical link center point 30. .. The rotation center axis 12 of the two rotating bodies 2a and 2b intersects the spherical link center point 30. The number (2) of the rotating bodies 2a and 2b is smaller than the number of degrees of freedom (3) of the posture of the tip side link hub 3.

By doing so, the tip side link hub 3 can be operated with three degrees of freedom of rotation with respect to the base end side link hub 1. That is, by rotating the two rotating bodies 2a and 2b, the tip end side link hub 3 can be moved along the spherical surface centered on the spherical surface link center point 30 with respect to the base end side link hub 1. , The tip side link hub 3 can be rotated around the rotation center axis 12. Further, since the posture of the tip side link hub 3 is controlled by the rotational movement of the rotating bodies 2a and 2b, a compact link operating device using the parallel link mechanism can be realized. Further, since the tip side link hub 3 moves along the spherical surface centered on the spherical link center point 30, it is easy to imagine the operation of the tip side link hub 3.

After diligent research, the inventor of this case found that the number of rotating bodies can be made smaller than the number of degrees of freedom of the tip side link hub. Specifically, as in the present embodiment, there are two rotating bodies (rotating bodies 2a and 2b). There are two link mechanisms 11, and the posture of the front end side link hub 3 has three degrees of freedom. By doing so, the posture of the front end side link hub 3 can be set to 3 degrees of freedom simply by preparing two rotating bodies and two link mechanisms 11. Therefore, the number of members constituting the parallel link mechanism can be reduced as compared with the case where three rotating bodies and three link mechanisms 11 are prepared in order to make the posture of the tip side link hub 3 have three degrees of freedom. .. Therefore, the space occupied by the parallel link mechanism due to the reduction of the number of members can be reduced, and the manufacturing cost of the parallel link mechanism can be reduced.

For example, as in the first embodiment, if the configuration is provided with three link mechanisms 11 and has three rotating bodies (however, there are two driveable rotating bodies 2a and 2b), for example, the driven rotating body 2z can only be driven. The link mechanism 11 (having the first link member 4c and the second link member 6c) connected to the link mechanism 11 is difficult to move smoothly. Therefore, the link mechanism 11 having the driven rotating body 2z, the first link member 4c, and the second link member 6c, which cannot be driven as in the present embodiment, is omitted, and only the driveable rotating bodies 2a and 2b are configured. As a result, smooth movement can be obtained only by the driveable rotating bodies 2a and 2b and the link member connected to them.

Normally, in order to set the number of degrees of freedom in the posture of the front end side link hub 3 to 3, it is considered that three rotating bodies as drive sources, which have the same number of degrees of freedom as the number of degrees of freedom, are required. However, in the present embodiment, the posture of the front end side link hub 3 can be set to three degrees of freedom only by the motors of the two rotating bodies 2a and 2b. This is based on the finding that the drive of one rotating body affects the operation of multiple mechanisms. As a result, in addition to the above-mentioned bending angle and turning angle, the entire rotation angle can be freely controlled in order to determine the posture of the tip side link hub 3. Therefore, in the present embodiment, the posture of the front end side link hub 3 has three degrees of freedom, and the link mechanism 11 has two degrees of freedom.

In the parallel link mechanism, the two rotating bodies may be rotatably connected to the base end side link hub 1 in a state where the respective rotation center axes 12 are arranged side by side so as to coincide with each other. The first link members 4a and 4b of the two link mechanisms 11 may be fixed to one of the two rotating bodies 2a and 2b, respectively. The two rotating bodies 2a and 2b may be laminated so that their respective rotation center axes 12 coincide with each other. With such a configuration, the same effect as described above can be obtained.

<Modification example>
FIG. 15 is a front schematic view showing a modified example of the parallel link mechanism according to the second embodiment. The parallel link mechanism shown in FIG. 15 basically has the same configuration as the parallel link mechanism shown in FIGS. 8 to 11, but the shape of the front end side link hub 3 and the configuration of the second rotary paired portions 26a and 26b. Is different from the parallel link mechanism shown in FIGS. 8 to 11. That is, the shape of the distal end side link hub 3 is plate-shaped, and the second link members 6a and 6b are rotatably connected directly to the end surface of the distal end side link hub 3. The planar shape of the distal link hub 3 may be the same as the planar shape of the distal link hub 3 in the parallel link mechanism shown in FIGS. 8 to 11, but may be any other shape. Further, as the configuration of the connection portion between the end surface of the distal end side link hub 3 and the second link members 6a and 6b, any configuration can be adopted as long as the second link member 6a can be rotatably connected to the distal end side link hub 3. ..

With such a configuration, the dimensions of the parallel link mechanism in the height direction can be reduced as compared with the parallel link mechanisms shown in FIGS. 8 to 11. As a result, the parallel link mechanism can be further miniaturized.

(Embodiment 3)
<Configuration of parallel link mechanism>
FIG. 16 is a schematic perspective view showing the configuration of the parallel link mechanism according to the third embodiment. The parallel link mechanism shown in FIG. 16 basically has the same configuration as the parallel link mechanism shown in FIGS. 8 to 11, but the shapes of the rotating bodies 2a and 2b and the second link member 6a of the link mechanism 11 The shape of 6b is different from the parallel link mechanism shown in FIGS. 8 to 11. That is, the length of the protruding portion of the rotating bodies 2a and 2b to which the first link members 4a and 4b are connected is different for each of the rotating bodies 2a and 2b. In the parallel link mechanism shown in FIG. 16, the base end side link hub 1 is viewed from the rotating body 2a from the length L1 of the protruding portion 22a of the rotating body 2a arranged at the position farthest from the base end side link hub 1. The length L2 of the protruding portion 22b of the rotating body 2b located on the side is long.

Corresponding to the difference in the lengths of the protrusions of the two rotating bodies 2a and 2b as described above, the shapes of the second link members 6a and 6b of the link mechanism 11 connected to the two rotating bodies 2a and 2b are different from each other. It's different. Specifically, based on the difference in the length of the protruding portion described above, the distances between the first rotating paired portions 25a and 25b and the second rotating paired even portion 26a and 26b in the two link mechanisms 11 are different. Therefore, the lengths of the second link members 6a and 6b in the two link mechanisms 11 are different from each other. Even when the sizes of the two link mechanisms 11 are different in this way, the first rotation paired parts 25a and 25b and the second rotation paired parts 26a and 26b are the same as the parallel link mechanisms shown in FIGS. 8 to 11. The relationship between the rotation center axis 12 and the spherical link center point 30 is maintained. That is, also in the parallel link mechanism shown in FIG. 16, in the two link mechanisms 11, the first central axes 15a and 15b of the first rotation paired portions 25a and 25b and the second center of the second rotating paired portions 26a and 26b. The axes 16a and 16b intersect at the spherical link center point 30. Further, the rotation center axis 12 of the two rotating bodies 2a and 2b intersects the spherical link center point 30.

<Action effect>
Also in the parallel link mechanism having the configuration as shown in FIG. 16, the tip side link hub 3 and the spherical link center point 30 are set with respect to the base end side link hub 1 as in the parallel link mechanism shown in FIGS. 8 to 11. It can be moved along a spherical surface centered on the center, and the front end side link hub 3 can be rotated around the rotation center axis 12.

(Embodiment 4)
<Configuration of parallel link mechanism>
FIG. 17 is a schematic partial cross-sectional view showing the configuration of the parallel link mechanism according to the fourth embodiment. FIG. 17 shows a schematic partial cross-sectional view of the link mechanism 11 of the parallel link mechanism from the first rotation paired portions 25a and 25b to the second rotating paired portions 26a and 26b. The parallel link mechanism shown in FIG. 17 basically has the same configuration as the parallel link mechanism shown in FIGS. 8 to 11, but the first rotating paired portions 25a and 25b and the second rotating paired pair portions 26a and 26b. It is different from the parallel link mechanism shown in FIGS. 8 to 11 in that bearings 39 and 49 as means for reducing rotational resistance are installed in each of the above. In FIG. 17, bearings 39 and 49 are installed in all the first rotary paired portions 25a and 25b and the second rotating paired pair portion 26a and 26b, but the first rotating paired pair portion 25a and 25b and the second rotating paired even portion are installed. Bearings may be installed in at least one of the portions 26a and 26b.

Specifically, in the first rotation paired portions 25a and 25b, a through hole is formed at the tip portion of the first link members 4a and 4b which is a part of the first rotating paired pair portion 25a and 25b. Through holes are also formed at the roots of the second link members 6a and 6b, which are part of the first rotation paired pair portions 25a and 25b.

The bearing 39 is arranged inside the through hole of the second link members 6a and 6b. Two bearings 39 are arranged in a double row inside the through hole. As the bearing 39, for example, a rolling bearing such as a ball bearing can be used. The bearing 39 includes an outer ring, an inner ring, and a plurality of rolling elements arranged between the outer ring and the inner ring. The outer ring of the bearing 39 is fixed to the through hole of the second link members 6a and 6b. Any method can be used for fixing the outer ring. For example, the outer ring may be press-fitted into the through hole of the second link members 6a and 6b. Further, the outer ring may be fixed by crimping in a state of being inserted into the through holes of the second link members 6a and 6b, or may be fixed by using a retaining ring.

The first link members 4a, 4b and the second link members 6a, 6b are arranged so that the through holes of the first link members 4a, 4b and the through holes of the second link members 6a, 6b are aligned coaxially. Bolts 17 are inserted into the through holes of the first link members 4a and 4b and the through holes of the second link members 6a and 6b. A nut 18 is fixed to the tip of the bolt 17. For example, a washer (not shown) is arranged between the nut 18 and the inner ring of the bearing 39. When the nut 18 tightens the inner ring of the bearing 39, the inner ring of the bearing 39 is fixed to the first link members 4a and 4b via the bolt 17 and the nut 18. With the above configuration, a preload is applied to the inner ring of the bearing 39.

At this time, the distance between the two bearings 39 may be increased by arranging washers or spacers between the bearings 39 arranged in multiple rows. Further, an angular contact ball bearing may be used as the two bearings 39. By doing so, the rigidity of the first rotary paired portions 25a and 25b including the bearing 39 can be improved.

In the second rotation paired portions 26a and 26b, the protruding portions of the tip side link hub 3 are arranged at the tip portions of the second link members 6a and 6b which are part of the second rotating paired pair portions 26a and 26b. A pair of wall portions is formed. A through hole is formed in the wall portion. A through hole is also formed in the protruding portion of the tip side link hub 3 which is arranged between the pair of wall portions and is a part of the second rotating paired pair portions 26a and 26b.

The bearing 49 is arranged inside the through hole formed in the protruding portion of the tip side link hub 3. Two bearings 49 are arranged in a double row inside the through hole. As the bearing 49, a rolling bearing such as a ball bearing can be used as in the bearing 39. The bearing 49 includes an outer ring, an inner ring, and a plurality of rolling elements arranged between the outer ring and the inner ring. The outer ring of the bearing 49 is fixed to the through hole of the tip side link hub 3. Any method can be used for fixing the outer ring. For example, the outer ring may be press-fitted into the through hole of the tip side link hub 3.

The protrusions of the second link members 6a and 6b and the tip side link hub 3 are arranged so that the through holes of the second link members 6a and 6b and the through holes of the tip side link hub 3 are aligned coaxially. Bolts 17 are inserted into the through holes of the second link members 6a and 6b and the through holes of the protruding portions of the tip side link hub 3. A nut 18 is fixed to the tip of the bolt 17. A washer 69 is arranged between the wall portion of the second link members 6a and 6b and the inner ring of the bearing 49. The nut 18 tightens the inner ring of the bearing 49 via the wall portion of the second link members 6a and 6b and the washer 69, so that the inner ring of the bearing 49 is fixed to the second link members 6a and 6b.

<Action effect>
In the parallel link mechanism, at least one of the first rotary paired portions 25a and 25b and the second rotating paired portions 26a and 26b may include bearings 39 and 49. In this case, the operation of the first rotary paired portions 25a and 25b or the second rotating paired pair portions 26a and 26b in which the bearings 39 and 49 are installed can be smoothed, and the positioning accuracy of the tip side link hub 3 can be improved. Can be done. Further, by installing the bearings 39 and 49, the friction torque of the first rotary paired portion 25a and 25b or the second rotating paired pair portion 26a and 26b in which the bearings 39 and 49 are installed is reduced, thereby reducing the rotational paired portion. It is possible to suppress the heat generation in. As a result, the life of the rotating kinematic pair can be extended. Further, by installing the bearings 39 and 49, it is possible to suppress rattling during operation of the rotational pair even portion as compared with the case where the bearings 39 and 49 are not used.

(Embodiment 5)
<Configuration of parallel link mechanism>
FIG. 18 is a schematic diagram showing the configuration of the parallel link mechanism according to the fifth embodiment. FIG. 19 is an enlarged schematic cross-sectional view of the region XIX of FIG.

The parallel link mechanism shown in FIGS. 18 and 19 basically has the same configuration as the parallel link mechanism shown in FIGS. 8 to 11, but each of the rotating bodies 2a and 2b has a rotation resistance reducing means. It differs from the parallel link mechanism shown in FIGS. 8 to 11 in that the bearing 59 is installed and the bolt 7 for fixing the rotating bodies 2a and 2b is hollow. Two bearings 59 are installed in each of the rotating bodies 2a and 2b. In addition, although the bearing 59 is installed in all the rotating bodies 2a and 2b in FIGS. 18 and 19, the bearing 59 may be installed in at least one of the plurality of rotating bodies 2a and 2b. .. Further, one bearing 59 may be installed on each of the rotating bodies 2a and 2b.

The bearing 59 includes an outer ring, an inner ring, and a plurality of rolling elements arranged between the outer ring and the inner ring. The outer ring of the bearing 59 is arranged so as to be in contact with the inner peripheral surfaces of the rotating bodies 2a and 2b. A protrusion 70 for supporting the outer ring of the bearing 59 is formed at the end of the inner peripheral surface of the rotating bodies 2a and 2b on the base end side link hub 1 side. The outer rings of the two bearings 59 are laminated along the direction of the rotation center axis 12 via the shim 33 in a state of being in contact with the inner peripheral surfaces of the rotating bodies 2a and 2b. A pressing member 71 is arranged on the upper surface of the rotating bodies 2a and 2b on the side opposite to the side facing the base end side link hub 1. The pressing member 71 is in contact with the outer ring of the bearing 59. The pressing member 71 is fixed to the rotating bodies 2a and 2b so as to press the outer ring of the bearing 59 toward the protrusion 70.

The inner peripheral surface of the inner ring of the bearing 59 is arranged so as to face the side surface of the bolt 7. That is, the bolt 7 is inserted into the opening defined by the inner peripheral surface of the inner ring. The washers 9 are arranged so as to sandwich the inner rings of the two bearings 59 from the direction along the rotation center axis 12. As shown in FIG. 18, the nut 8 is fixed to the tip of the bolt 7 from the lower side of the base end side link hub 1. By tightening the nut 8, the base end side link hub 1 is pressed toward the tip end side link hub 3 side. As a result, the inner ring of the bearing 59 is fixed between the head of the bolt 7 and the base end side link hub 1 via the washer 9. That is, the inner ring of the bearing 59 is fixed to the bolt 7. In this way, the bearing 59 can be preloaded.

<Action effect>
In the parallel link mechanism, at least one of the rotating bodies 2a and 2b includes a bearing 59. In this case, the operation of the rotating bodies 2a and 2b on which the bearing 59 is installed can be smoothed, and the positioning accuracy of the tip side link hub 3 can be improved. Further, by installing the bearing 59, it is possible to suppress heat generation in the rotating bodies 2a and 2b by reducing the friction torque of the rotating bodies 2a and 2b in which the bearing 59 is installed.

Further, in the parallel link mechanism shown in FIGS. 18 and 19, since the bolt 7 is hollow, for example, a member such as a connection cable to a device installed on the tip side link hub 3 is hollow in the bolt 7. Can be placed in minutes.

(Embodiment 6)
<Configuration of parallel link mechanism>
FIG. 20 is a schematic perspective view showing the configuration of the parallel link mechanism according to the sixth embodiment. FIG. 21 is a front schematic diagram of the parallel link mechanism shown in FIG. 20. FIG. 22 is a schematic cross-sectional view of the line segment XXII-XXII of FIG. FIG. 23 is a schematic top view of the rotating body of the parallel link mechanism shown in FIG. 20.

The parallel link mechanism shown in FIGS. 20 to 23 basically has the same configuration as the parallel link mechanism shown in FIGS. 8 to 11, but the shapes of the rotating bodies 2a and 2b and the first link members 4a and 4b are provided. The configuration of the connection portion between the rotating body 2a and 2b is different from that of the parallel link mechanism shown in FIGS. 8 to 11. That is, in the parallel link mechanism shown in FIGS. 20 to 23, through holes 27a and 27b having a C-shaped plane shape are formed in the rotating bodies 2a and 2b. The rotating bodies 2a and 2b include connecting portions 28a and 28b that connect the inner peripheral side and the outer peripheral side of the through holes 27a and 27b. The rotating bodies 2a and 2b basically have the same planar shape.

The first link members 4a and 4b of the two link mechanisms 11 are fixed to the connecting portions 28a and 28b of the rotating bodies 2a and 2b, respectively. That is, the first link members 4a and 4b are connected to the rotating bodies 2a and 2b inside the outer peripheral portions of the rotating bodies 2a and 2b. Any method can be used as the method of fixing the first link members 4a and 4b to the connecting portions 28a and 28b of the rotating bodies 2a and 2b. For example, the first link members 4a and 4b may be fixed to the connecting portions 28a and 28b by using a fixing member such as a screw.

The first link member 4b fixed to the connecting portion 28b of the rotating body 2b passes through the inside of the through hole 27a of the rotating body 2a and extends to the tip side link hub 3 side.

<Action effect>
In the parallel link mechanism, the two rotating bodies 2a and 2b are formed with annular through holes 27a and 27b so as to surround the rotation center axis 12. The two rotating bodies 2a and 2b include a first rotating body 2a and a second rotating body 2b arranged on the side where the base end side link hub 1 is located when viewed from the first rotating body 2a. The first link member 4b connected to the second rotating body 2b passes through the inside of the through hole 27a of the first rotating body 2a and extends toward the tip side link hub 3.

In this case, the parallel link mechanism can be made smaller than the configuration in which the first link member 4b is arranged outside the rotating bodies 2a and 2b. Further, since the first link member 4b is arranged so as to pass through the through hole 27a formed in an annular shape, even if the rotating body 2b rotates relative to the rotating body 2a, the first link member 4b remains. Does not interfere with the rotating body 2a.

(Embodiment 7)
<Structure of link operating device>
FIG. 24 is a schematic perspective view showing the configuration of the link operating device according to the seventh embodiment. FIG. 25 is a schematic diagram showing the configuration of the link actuating device shown in FIG. 24. The link actuating device shown in FIGS. 24 and 25 is basically a link actuating device using the parallel link mechanism shown in FIGS. 20 to 23. The link actuating device shown in FIGS. 24 and 25 mainly includes a parallel link mechanism and attitude control drive sources 35a and 35b for driving the parallel link mechanism.

In the link actuating device shown in FIGS. 24 and 25, the base end side link hub 1 is formed so as to extend outward from the outer periphery of the rotating bodies 2a and 2b. That is, the size of the base end side link hub 1 in the plan view is larger than the size of the rotating bodies 2a and 2b in the plan view. The planar shape of the base end side link hub 1 may be a circular shape as shown in FIG. 7, but may be any other shape, for example, a polygonal shape such as a quadrangle or a triangle, or an elliptical shape. good. Two attitude control drive sources 35a and 35b are fixed to the base end side link hub 1 via fixing portions 36a and 36b. As the attitude control drive sources 35a and 35b, for example, an electric motor or the like can be used.

The attitude control drive sources 35a and 35b are connected to the rotating bodies 2a and 2b so as to be able to transmit the driving force via the gears 38 and the rotation transmitting members 37a and 37b, respectively. The attitude control drive sources 35a and 35b are arranged at substantially equal intervals in the circumferential direction about the rotation center axis 12 in a plan view. The attitude control drive sources 35a and 35b may be arranged at different intervals in the circumferential direction.

Specifically, the attitude control drive sources 35a and 35b each include a rotation shaft, and a gear 38 is connected to the end of the rotation shaft. Further, rotation transmission members 37a and 37b are fixed to the outer peripheral portions of the rotating bodies 2a and 2b by fixing members 47 such as screws. The rotation transmission members 37a and 37b are annular members having a gear portion on the outer peripheral portion. As a method of fixing the rotation transmitting members 37a and 37b to the rotating bodies 2a and 2b, any method other than the method using the fixing member 47 described above can be adopted as long as the required strength and accuracy can be obtained. For example, the rotation transmission members 37a and 37b may be fixed to the rotating bodies 2a and 2b by a method such as adhesion, press fitting, or caulking.

The gear portions of the rotation transmission members 37a and 37b mesh with the gear 38 connected to the rotation shafts of the attitude control drive sources 35a and 35b. By rotating the rotation shafts of the attitude control drive sources 35a and 35b, the gear 38 and the rotation transmission members 37a and 37b rotate, and as a result, the rotating bodies 2a and 2b can be rotationally driven.

The first link members 4a and 4b of the link mechanism 11 are fixed to the rotating bodies 2a and 2b by screws as fixing members 46. When the rotating bodies 2a and 2b are rotated by the attitude control drive sources 35a and 35b, the position of the link mechanism 11 around the rotation center axis 12 is changed. As a result, the posture of the tip side link hub 3 can be changed.

<Action effect>
The link actuating device according to the present disclosure includes the parallel link mechanism and the attitude control drive sources 35a and 35b. The attitude control drive sources 35a and 35b rotate two or more (two) rotating bodies 2a and 2b, and arbitrarily change the attitude of the distal end side link hub 3 with respect to the proximal end side link hub 1. In the present embodiment, the number (two) of the two or more attitude control drive sources 35a and 35b is smaller than the number of degrees of freedom (3) of the posture of the tip side link hub 3. The attitude control drive source 35a rotates the rotating body 2a, and the attitude control drive source 35b rotates the rotating body 2b. Therefore, the number of drive sources for attitude control (2) and the number of driveable rotating bodies (2) are equal. That is, as in the present embodiment, there are two rotating bodies (rotating bodies 2a and 2b), all of which can be rotated by the attitude control drive source. In the present specification, even when the rotating body can be rotated by the drive source for attitude control such as an external motor, the external motor directly rotates the rotating body, so that the rotating body has a built-in motor or the like. It is considered that the rotating body can be driven spontaneously (it does not follow the driven rotating body 2z of the first embodiment) as in the second embodiment. In this embodiment, there are two attitude control drive sources (attitude control drive sources 35a and 35b). The posture of the tip side link hub 3 has 3 degrees of freedom. The number of attitude control drive sources (drive sources) (2) is smaller than the number of degrees of freedom in attitude of the front end side link hub 3 (3).

In this case, the attitude control drive sources 35a and 35b can individually control the plurality of link mechanisms 11 so that the tip side link hub 3 can be operated in a wide range and with precision. Further, by using the parallel link mechanism as described above, a lightweight and compact link operating device can be realized. In the present embodiment as well, as in the case of the second embodiment, as a result of the inventor's diligent research, when three drive sources for attitude control are prepared in order to make the attitude of the tip side link hub 3 three degrees of freedom. In comparison, the number of members constituting the link actuating device can be reduced. Therefore, the space occupied by the parallel link mechanism due to the reduction of the number of members can be reduced, and the manufacturing cost of the parallel link mechanism can be reduced.

The link actuating device includes rotation transmitting members 37a and 37b connected to the rotating bodies 2a and 2b. The attitude control drive sources 35a and 35b rotate two rotating bodies 2a and 2b via rotation transmission members 37a and 37b. In this case, since the rotation transmitting members 37a and 37b as separate members are installed on the rotating bodies 2a and 2b, the material of the rotation transmitting members 37a and 37b can be selected independently of the materials of the rotating bodies 2a and 2b.

Of the three rotating bodies of the parallel link mechanism according to the first embodiment of FIGS. 1 to 7, the two rotating bodies 2a and 2b that can be driven have two drive sources for attitude control 35a similar to those in FIGS. 24 and 25. , 35b may be attached.

<Structure and action of modified examples>
FIG. 26 is a schematic view showing a first modification of the link actuating device according to the seventh embodiment. FIG. 27 is a schematic view showing a second modification of the link actuating device according to the seventh embodiment. FIG. 28 is a schematic perspective view showing a third modification of the link operating device according to the seventh embodiment.

The link actuating device shown in FIG. 26 basically has the same configuration as the link actuating device shown in FIGS. 24 and 25, except that the rotating bodies 2a and 2b and the rotation transmitting member are integrally formed. It is different from the link actuating device shown in FIGS. 24 and 25. In the link actuating device shown in FIG. 26, the outer peripheral portions of the rotating bodies 2a and 2b partially protrude to form the rotation transmitting portions 48a and 48b. The outer peripheral portions of the rotation transmitting portions 48a and 48b are gear portions that mesh with the gear 38.

That is, in the link actuating device shown in FIG. 26, the two rotating bodies 2a and 2b include rotation transmitting portions 48a and 48b. The two attitude control drive sources 35a and 35b rotate the two rotating bodies 2a and 2b via the rotation transmission units 48a and 48b.

To summarize the characteristic configuration of the link actuating device, since a part of the rotating bodies 2a and 2b is the rotation transmitting portions 48a and 48b, the rotation transmitting member is a separate member from the rotating bodies 2a and 2b. Compared to the case where 37a and 37b are connected to the rotating bodies 2a and 2b, the number of parts of the link operating device can be reduced and the manufacturing process can be simplified.

The link actuating device shown in FIG. 27 basically has the same configuration as the link actuating device shown in FIGS. 24 and 25, but has the shapes of the rotating bodies 2a and 2b, the shapes of the rotation transmitting members 37a and 37b, and the attitude control. The arrangement of the drive sources 35a and 35b, the shape of the base end side link hub 1, and the configuration of the connection portion of the first link members 4a and 4b to the rotating bodies 2a and 2b are different from those of the link actuating device shown in FIGS. 24 and 25. ..

The rotating bodies 2a and 2b of the link actuating device shown in FIG. 27 are formed with through holes 27a and 27b having a C-shaped plane shape, and the inner peripheral surfaces of the through holes 27a and 27b have internal gears. The rotation transmission members 37a and 37b are fixed. Any method can be used for fixing the rotation transmission members 37a and 37b to the rotating bodies 2a and 2b, and for example, a method such as press fitting is used.

The rotation transmission members 37a and 37b have an annular shape. A gear portion, which is an internal gear, is formed on the inner peripheral surfaces of the rotation transmission members 37a and 37b. Gears 38 connected to the rotation shafts of the attitude control drive sources 35a and 35b are arranged on the inner peripheral side of the rotation transmission members 37a and 37b. The gear 38 meshes with the gear portions of the rotation transmission members 37a and 37b. By rotating the rotation shafts of the attitude control drive sources 35a and 35b, the rotating bodies 2a and 2b can be rotated via the gears 38 and the rotation transmission members 37a and 37b.

The rotation transmission members 37a and 37b are fixed to the side wall on the outer peripheral side of the through holes 27a and 27b of the rotating bodies 2a and 2b. Specifically, it is a side wall on the outer peripheral side of the through holes 27a and 27b of the rotating bodies 2a and 2b, and a recess is formed at the end on the base end side link hub 1 side. The rotation transmission members 37a and 37b are fixed to the rotating bodies 2a and 2b in a state where the outer peripheral portions of the rotation transmission members 37a and 37b are fitted in the recesses. It should be noted that one of the rotation transmitting members 37a and 37b is on the base end side link hub 1 side of the connecting portions 28a and 28b connecting the inner peripheral side portions and the outer peripheral side portions of the through holes 27a and 27b in the rotating bodies 2a and 2b. The part is arranged. Further, on the base end side link hub 1 side of the connecting portions 28a and 28b of the rotating bodies 2a and 2b, a recess is formed in which the gear 38 can be arranged on the inner peripheral side of the rotation transmitting members 37a and 37b. There is.

In the link actuating device shown in FIG. 27, the attitude control drive sources 35a and 35b are installed on the back surface of the base end side link hub 1 (the surface opposite to the surface facing the rotating bodies 2a and 2b). The attitude control drive sources 35a and 35b are arranged at positions overlapping with the rotating bodies 2a and 2b in a plan view. The rotation shaft 41 of the attitude control drive source 35a is in a state of being inserted into the first through hole formed in the base end side link hub 1 and the through holes 27a and 27b of the rotating bodies 2a and 2b. Although not shown, the rotation axis of the attitude control drive source 35b is inserted into the second through hole formed in the base end side link hub 1 and the through hole 27b of the rotating body 2b. The gear 38 is connected to the end of each rotation shaft of the attitude control drive sources 35a and 35b.

Since the attitude control drive sources 35a and 35b are arranged at positions overlapping with the rotating bodies 2a and 2b in a plan view as described above, the proximal end side link hub 1 is the outer periphery of the rotating bodies 2a and 2b as shown in FIG. 24. Does not include more outwardly protruding parts. Further, the first link members 4a and 4b are connected to the outer periphery of the rotating bodies 2a and 2b in the same manner as the parallel link mechanism shown in FIG.

In the link actuating device shown in FIG. 27, the same effect as that of the link actuating device shown in FIGS. 24 and 25 can be obtained, and the size of the base end side link hub 1 is the link shown in FIGS. 24 and 25. Since it is smaller than the size of the base end side link hub 1 of the actuating device, the occupied volume of the entire link actuating device can be relatively small.

The link actuating device shown in FIG. 28 basically has the same configuration as the link actuating device shown in FIGS. 24 and 25, but the rotational driving force from the attitude control drive sources 35a and 35b to the rotating bodies 2a and 2b. The configuration for transmitting the above is different from the link actuating device shown in FIGS. 24 and 25. Specifically, in the link actuating device shown in FIG. 28, the pulley 58 is fixed to the rotating shafts of the attitude control drive sources 35a and 35b. Belts 57a and 57b are hung between the two pulleys 58 and the rotating bodies 2a and 2b, respectively. That is, the inner peripheral surfaces of the belts 57a and 57b are in contact with the outer circumferences of the pulleys 58 fixed to the rotation shafts of the attitude control drive sources 35a and 35b, and are also in contact with the outer circumferences of the rotating bodies 2a and 2b. By rotating the rotation shafts of the attitude control drive sources 35a and 35b, the pulley 58 is rotated, and the rotating bodies 2a and 2b can be rotated via the belts 57a and 57b.

The link actuating device shown in FIG. 28 can also obtain the same effect as the link actuating device shown in FIGS. 24 and 25. Further, in the above-mentioned link actuating device, any other configuration may be adopted as the configuration for transmitting the driving force from the attitude control drive sources 35a and 35b to the rotating bodies 2a and 2b. For example, a bevel gear or a worm gear may be used so that the direction of the rotation axis of the attitude control drive sources 35a and 35b intersects with the direction of the rotation center axis 12 of the rotating bodies 2a and 2b.

(Embodiment 8)
<Structure of link operating device>
FIG. 29 is a schematic perspective view showing the configuration of the link operating device according to the eighth embodiment. FIG. 30 is a schematic diagram showing the configuration of the link actuating device shown in FIG. 29. FIG. 31 is an enlarged schematic cross-sectional view of the region XXXI of FIG. FIG. 32 is a schematic cross-sectional view of the line segment XXXII-XXXII of FIG. 30.

The link actuating device shown in FIGS. 29 to 32 basically has the same configuration as the link actuating device shown in FIGS. 24 and 25, but transmits a driving force from the attitude control drive source to the parallel link mechanism. The configuration of the mechanism is different from that of the link device shown in FIGS. 24 and 25.

In the link actuating device shown in FIGS. 29 to 32, the parallel link mechanism and the attitude control drive source are provided so as to transmit the driving force in a non-contact manner. Specifically, the parallel link mechanism and the attitude control drive source are magnetically coupled.

A magnet 67a is fixed to the outer peripheral surface 29a of the rotating body 2a. A magnet 67b is fixed to the outer peripheral surface 29b of the rotating body 2b. That is, each rotating body 2a and 2b includes magnets 67a and 67b. As a method of fixing the magnets 67a and 67b to the rotating bodies 2a and 2b, any method other than the method using the fixing member 47 described above can be adopted as long as the required strength and accuracy can be obtained. For example, the magnets 67a and 67b may be fixed to the rotating bodies 2a and 2b by a method such as bonding, press-fitting, or caulking.

The attitude control drive source includes a yoke portion 65, a plurality of teeth portions 66a and 66b, stator coils 68a and 68b, and a control unit (not shown) that controls the current value flowing through the stator coils 68a and 68b. There is.

As shown in FIG. 30, the yoke portion 65 is fixed to the outer peripheral end portion of the base end side link hub 1 and projects toward the distal end side with respect to the outer peripheral end portion. The yoke portion 65 is provided so as to face the magnets 67a and 67b in the radial direction about the rotation center axis 12. The yoke portion 65 is arranged on the outer peripheral side of the magnets 67a and 67b in the radial direction.

As shown in FIGS. 30 and 32, the plurality of tooth portions 66a and 66b are fixed to the inner peripheral surface of the yoke portion 65 and project inward in the radial direction.

The plurality of tooth portions 66a are arranged so as to be spaced apart from each other in the circumferential direction. The stator coil 68a is wound around each tooth portion 66a. The plurality of tooth portions 66a and the stator coil 68a are provided so as to face the magnet 67a in the radial direction. The plurality of tooth portions 66a and the stator coil 68a are arranged on the outer peripheral side of the magnet 67a in the radial direction.

The plurality of tooth portions 66b are arranged so as to be spaced apart from each other in the circumferential direction. The stator coil 68b is wound around each tooth portion 66b. The plurality of tooth portions 66b and the stator coil 68b are provided so as to face the magnet 67b in the radial direction. The plurality of tooth portions 66b and the stator coil 68b are arranged on the outer peripheral side of the magnet 67b in the radial direction.

The distance between two adjacent tooth portions 66a and 66b in the circumferential direction is, for example, equal. In a plan view, the plurality of tooth portions 66a and the stator coil 68a and the plurality of tooth portions 66b and the stator coil 68b are arranged so as to overlap each other, for example.

The control unit is provided so as to individually control the current value flowing through the stator coils 68a and 68b.

In the link actuating device shown in FIGS. 29 to 32, the magnets 67a and 67b fixed to the rotating bodies 2a and 2b and the attitude control drive source constitute a so-called inner rotor type motor. When a current is supplied to the stator coils 68a and 68b from the control unit of the attitude control drive source, the magnets 67a and 67b rotate, and as a result, the rotating bodies 2a and 2b can be rotationally driven. As the rotating bodies 2a and 2b rotate, the position of the link mechanism 11 around the rotation center axis 12 is changed. As a result, the posture of the tip side link hub 3 can be changed. Such an inner rotor type motor is a so-called direct drive system because the rotational force is transmitted to the drive target (rotating bodies 2a, 2b). If the rotating bodies 2a and 2b can be driven by using a direct drive type motor, the capacity of the drive source can be reduced. Further, since the motor is a hollow type direct drive type motor and wiring can be built in the hollow portion, the capacity of the entire device can be reduced.

The parallel link mechanism of the link actuating device shown in FIGS. 29 to 32 basically has the same configuration as the parallel link mechanism shown in FIGS. 20 to 23, but each of the rotating bodies 2a and 2b has a rotational resistance. The difference is that the bolt 7 is connected to the bolt 7 via a bearing 59 as a reducing means, and the bolt 7 is hollow. Further, as shown in FIG. 31, a shim 33 is sandwiched between the pair of bearings 59 between the rotating body 2a and the bolt 7. A pressing member 71 is provided so as to cover the portion of the rotating body 2a on the inner peripheral side of the through hole 27a and the bearing 59. A preload is applied to the bearing 59 by fixing the inner ring of the bearing 59 to the bolt 7 with the bolt 7 and the nut 8. The configuration shown in FIG. 31 is the same for the rotating body 2b. The parallel link mechanism of the link actuating device according to the present embodiment may have the same configuration as the parallel link mechanism shown in FIGS. 20 to 23.

<Action effect>
Since the link operating device according to the present embodiment has basically the same configuration as the link operating device according to the seventh embodiment, the same effect as that of the link operating device according to the seventh embodiment can be obtained.

Further, in the link operating device according to the present embodiment, the parallel link mechanism and the attitude control drive source are magnetically connected. That is, the link actuating device includes two or more (two) rotating bodies 2a and 2b and an attitude control drive source (yoke portion 65, a plurality of tooth portions 66a and 66b, and a stator coils 68a and 68b) outside the rotating bodies 2a and 2b. , Control unit) is magnetically connected. Therefore, in the link operating device according to the present embodiment, the link operating device according to the seventh embodiment in which the parallel link mechanism (two rotating bodies 2a and 2b) and the attitude control drive source are mechanically connected. In comparison with this, the loss of driving force between the parallel link mechanism and the attitude control drive source is suppressed. As a result, the link operating device according to the present embodiment has higher operating efficiency and energy can be achieved as compared with the link operating device according to the seventh embodiment.

Further, in the link operating device according to the present embodiment, since it is not necessary to provide a so-called backlash in the mechanism for transmitting the driving force, the speed is higher and higher than that of the link operating device according to the seventh embodiment. It can operate with high precision.

<Structure and action of modified examples>
FIG. 33 is a schematic view showing a first modification of the link actuating device according to the eighth embodiment. FIG. 34 is a schematic diagram showing the configuration of the link actuating device shown in FIG. 33. FIG. 35 is an enlarged schematic cross-sectional view of the region XXXV of FIG. 34. FIG. 36 is a schematic cross-sectional view of the line segment XXXVI-XXXVI of FIG. 34. FIG. 37 is a schematic perspective view showing a second modification of the link operating device according to the eighth embodiment. FIG. 38 is a schematic view showing a third modification of the link actuating device according to the eighth embodiment.

The link actuating device shown in FIGS. 33 to 36 basically has the same configuration as the link actuating device shown in FIGS. 29 to 32, but has magnets 77a and 77b fixed to the rotating bodies 2a and 2b and the above-mentioned posture. It differs from the link actuating device shown in FIGS. 29 to 32 in that the control drive source constitutes a so-called outer rotor type motor.

The rotating bodies 2a and 2b are located on the proximal end side with respect to the surface connected to the bolt 7 via the bearing 59, and have an inner peripheral surface facing inward in the radial direction. The magnets 77a and 77b are fixed to the inner peripheral surfaces of the rotating bodies 2a and 2b. In other words, the rotating bodies 2a and 2b are formed with recesses recessed with respect to the surface located on the base end side link hub 1 side on the inner peripheral side in the radial direction. The inner peripheral surface is composed of the wall surface of each recess. The magnets 77a and 77b are arranged in each recess.

The attitude control drive source includes yoke portions 75a and 75b, a plurality of tooth portions 76a and 76b, stator coils 78a and 78b, and a control unit (not shown) that controls the current value flowing through the stator coils 78a and 78b. is doing.

The yoke portions 75a and 75b have an inner peripheral surface connected to the outer peripheral surface of the bolt 7. The yoke portion 75a is arranged between the bearing 59 connecting the rotating body 2a and the bolt 7 and the bearing 59 connecting the rotating body 2b and the bolt 7. The yoke portion 75a is provided so as to face the magnet 77a in the radial direction. The yoke portion 75a is arranged on the outer peripheral side of the magnet 77a in the radial direction.

The yoke portion 75b is arranged on the base end side link hub 1 side of the bearing 59 that connects the rotating body 2b and the bolt 7. The yoke portion 75b is provided so as to face the magnet 77b in the radial direction. The yoke portion 75b is arranged on the outer peripheral side of the magnet 77b in the radial direction.

As shown in FIG. 34, the plurality of tooth portions 76a and 76b are fixed to the outer peripheral surfaces of the yoke portions 75a and 75b and project outward in the radial direction. The plurality of tooth portions 76a and 76b are arranged in the recesses of the rotating bodies 2a and 2b.

The plurality of tooth portions 76a are arranged so as to be spaced apart from each other in the above-mentioned circumferential direction. The stator coil 78a is wound around each tooth portion 76a. The plurality of tooth portions 76a and the stator coil 78a are provided so as to face the magnet 77a in the radial direction. The plurality of tooth portions 76a and the stator coil 78a are arranged on the inner peripheral side of the magnet 77a in the radial direction.

The plurality of tooth portions 76b are arranged at intervals from each other in the circumferential direction. The stator coil 78b is wound around each tooth portion 76b. The plurality of tooth portions 76b and the stator coil 78b are provided so as to face the magnet 77b in the radial direction. The plurality of tooth portions 76b and the stator coil 78b are arranged on the inner peripheral side of the magnet 77b in the radial direction.

The spacing between two adjacent tooth portions 76a and 76b in the circumferential direction is, for example, equal. In a plan view, the plurality of tooth portions 76a and the stator coil 78a and the plurality of tooth portions 76b and the stator coil 78b are arranged so as to overlap each other, for example.

The control unit is provided so as to individually control the current value flowing through the stator coils 78a and 78b.

In the link actuating device shown in FIGS. 33 to 36, the magnets 77a and 77b fixed to the rotating bodies 2a and 2b and the attitude control drive source constitute a so-called outer rotor type motor. When a current is supplied to the stator coils 78a and 78b from the control unit of the attitude control drive source, the magnets 77a and 77b rotate, and as a result, the rotating bodies 2a and 2b can be rotationally driven. As the rotating bodies 2a and 2b rotate, the position of the link mechanism 11 around the rotation center axis 12 is changed. As a result, the posture of the tip side link hub 3 can be changed. Such an outer rotor type motor is a so-called direct drive system because the rotational force is transmitted to the drive target (rotating bodies 2a, 2b). If the rotating bodies 2a and 2b can be driven by using a direct drive type motor, the capacity of the drive source can be reduced. Further, since the motor is a hollow type direct drive type motor and wiring can be built in the hollow portion, the capacity of the entire device can be reduced.

The link actuating device shown in FIG. 37 basically has the same configuration as the link actuating device shown in FIGS. 29 to 32, but has a rotation amount of two or more (for example, two) rotating bodies 2a and 2b. It differs from the link actuating device shown in FIGS. 29 to 32 in that it is further provided with a rotation amount detecting mechanism for detection.

The rotation amount detection mechanism may have an arbitrary configuration as long as it can detect the rotation amount of the rotating bodies 2a and 2b, but is configured as, for example, an optical encoder.

The rotation amount detecting mechanism for detecting the rotation amount of the rotating body 2a has a detected unit 81a fixed to the rotating body 2a and a detection unit (not shown) for detecting the movement amount of the detected unit 81a. There is. The rotation amount detecting mechanism for detecting the rotation amount of the rotating body 2b has a detected unit 81b fixed to the rotating body 2b and a detection unit (not shown) for detecting the movement amount of the detected unit 81b. There is.

The detected portion 81a is fixed to the outer peripheral portion of the rotating body 2a located on the outer peripheral side of the through hole 27a, and protrudes toward the outer peripheral side from the magnet 67a. The detected portion 81a is fixed to, for example, a surface of the rotating body 2a facing the proximal end side. The detected portion 81a is arranged, for example, between the stator coils 68a and 68b. The outer peripheral end portion of the detected portion 81a is arranged on the outer peripheral side of the stator coils 68a and 68b and on the inner peripheral side of the yoke portion 65, for example. The detection unit that detects the movement amount of the detected unit 81a is fixed to, for example, the yoke portion 65.

The detected portion 81b is fixed to the outer peripheral portion of the rotating body 2b located on the outer peripheral side of the through hole 27b, and protrudes toward the outer peripheral side of the magnet 67b. The detected portion 81b is fixed to, for example, a surface of the rotating body 2b facing the proximal end side. The detected portion 81b is arranged, for example, below the stator coil 68b. The outer peripheral end portion of the detected portion 81b is arranged on the outer peripheral side of the stator coil 68b and on the inner peripheral side of the yoke portion 65, for example. The detection unit that detects the movement amount of the detected unit 81b is fixed to, for example, the yoke portion 65.

Each detection unit has, for example, facing portions arranged so as to face each other with the outer peripheral ends of the detected portions 81a and 81b in the direction along the rotation center axis 12. One of the facing portions located on the proximal end side with respect to the detected portions 81a and 81b and the portion located on the distal end side with respect to the detected portions 81a and 81b are configured as a light emitting portion and the other as a light receiving portion. ing. The optical axis reaching the light receiving portion from the light emitting portion is, for example, parallel to the direction along the rotation center axis 12. The detection units are arranged at intervals from each other in the circumferential direction, for example, in a plan view.

In the link actuating device shown in FIG. 37, the rotation amount detection mechanism detects each rotation amount of the rotating bodies 2a and 2b from each movement amount of the detected portions 81a and 81b detected by each detection unit. -Compared to the link actuating device shown in FIG. 32, the operation of the front end side link hub 3 can be controlled more precisely based on the amount of rotation.

The link actuating device shown in FIG. 38 basically has the same configuration as the link actuating device shown in FIGS. 33 to 36, but has a rotation amount detecting mechanism for detecting the rotation amount of the rotating bodies 2a and 2b. Further, it is different from the link actuating device shown in FIGS. 33 to 36 in that it is provided.

The rotation amount detection mechanism of the link actuating device shown in FIG. 38 basically has the same configuration as the rotation amount detection mechanism of the link actuating device shown in FIG. 37, but is directed toward the inner peripheral side of the magnets 77a and 77b. It is different from the link actuating device shown in FIGS. 33 to 36 in that it has a detection unit 83a and 83b protruding from the surface and a detection unit fixed to the bolt 7.

The detected portion 83a is fixed to the outer peripheral portion of the rotating body 2a located on the outer peripheral side of the magnet 77a, and protrudes toward the inner peripheral side of the magnet 77a. The detected portion 83a is fixed to, for example, a surface of the rotating body 2a facing the proximal end side. The outer peripheral end portion of the detected portion 83a is arranged so as to overlap the stator coil 78a in a plan view, for example. The outer peripheral end portion of the detected portion 83a is arranged on the outer peripheral side of the yoke portion 75a. The detection unit 84a that detects the movement amount of the detected unit 83a is fixed to, for example, the yoke portion 75a.

The detected portion 83b is fixed to the outer peripheral portion of the rotating body 2b located on the outer peripheral side of the magnet 77b, and protrudes toward the inner peripheral side of the magnet 77b. The detected portion 83b is fixed to, for example, a surface of the rotating body 2b facing the proximal end side. The outer peripheral end portion of the detected portion 83b is arranged so as to overlap the stator coil 78b in a plan view, for example. The outer peripheral end of the detected portion 83b is arranged on the outer peripheral side of the yoke portion 75b. A detection unit (not shown) that detects the amount of movement of the detected unit 83b is fixed to, for example, a yoke unit 75b.

Each detection unit has, for example, facing portions arranged so as to face each other with the inner peripheral end portions of the detected portions 83a and 83b in the direction along the rotation center axis 12. One of the facing portions located on the proximal end side with respect to the detected portions 83a and 83b and the portion located on the distal end side with respect to the detected portions 83a and 83b are configured as a light emitting portion and the other as a light receiving portion. ing. The detection units are arranged at intervals from each other in the circumferential direction, for example, in a plan view.

In the link operating device shown in FIG. 38, the rotation amount of each of the rotating bodies 2a and 2b is detected by the rotation amount detecting unit (rotation amount detecting mechanism), so that the link operating device shown in FIGS. 33 to 36 is compared with the link operating device shown in FIGS. 33 to 36. The operation of the tip side link hub 3 can be controlled more precisely based on the amount of rotation.

Further, even if each of the above-mentioned link actuating devices, for example, the link actuating device shown in FIGS. 24 to 26 and the link actuating device shown in FIG. 28, also has the rotation amount detecting mechanism shown in FIG. 37 or FIG. 38. good. Each detection unit is fixed to, for example, a base end side link hub 1 and is fixed to a support member protruding toward the tip end side on the outer peripheral side of the rotating bodies 2a and 2b. Each detection unit is arranged at a distance from the attitude control drive source in the circumferential direction, for example, in a plan view.

(Embodiment 9)
<Configuration of parallel link mechanism>
FIG. 39 is a schematic diagram showing the configuration of the parallel link mechanism according to the ninth embodiment. The parallel link mechanism shown in FIG. 39 basically has the same configuration as the parallel link mechanism shown in FIGS. 1 to 4, but the shapes and arrangements of the rotating bodies 2a and 2b are shown in FIGS. 1 to 4. It is different from the parallel link mechanism.

In the parallel link mechanism shown in FIG. 39, the rotating bodies 2a and 2b are provided in an annular shape. The rotating bodies 2a and 2b are arranged side by side in the radial direction so that the respective rotation center axes 12 coincide with each other.

The dimensions of the rotating bodies 2a and 2b are different from each other. The inner diameter of the rotating body 2a is longer than the outer diameter of the bolt 7. The outer diameter of the rotating body 2a is shorter than the inner diameter of the rotating body 2b. The rotating body 2a is arranged on a first circumference centered on the rotation center axis 12 in a plan view. The rotating body 2b is arranged on a second circumference centered on the rotation center axis 12 in a plan view and having a radius longer than the first circumference.

The rotating body 2a is arranged in a space surrounded by the inner peripheral surface of the rotating body 2b. The rotating body 2a is connected to the bolt 7 via a bearing 99a. The inner ring of the bearing 99a is fixed to the bolt 7. The outer ring of the bearing 99a is fixed to the rotating body 2a.

The rotating body 2b is connected to the rotating body 2a via a bearing 99b. The inner ring of the bearing 99b is fixed to the rotating body 2a. The outer ring of the bearing 99b is fixed to the rotating body 2b.

As the bearings 99a and 99b, rolling bearings such as ball bearings can be used.
In the parallel link mechanism shown in FIG. 39, the distances between the rotating bodies 2a and 2b and the proximal end side link hub 1 are provided to be equal to each other. In the parallel link mechanism shown in FIG. 39, the lengths of the first link members 4a and 4b are provided to be equal to each other.

In the parallel link mechanism shown in FIG. 39, the rotating bodies 2a and 2b are not stacked in the direction along the rotation center axis 12, but are arranged side by side in the radial direction so that the respective rotation center axes 12 coincide with each other. Therefore, as compared with the parallel link mechanism shown in FIGS. 1 to 4, miniaturization in the direction along the rotation center axis 12 is realized.

(Embodiment 10)
<Structure of link operating device>
FIG. 40 is a schematic diagram showing the configuration of the link operating device according to the tenth embodiment. The link actuating device shown in FIG. 40 is basically a link actuating device using the parallel link mechanism shown in FIG. 39. The link actuating device shown in FIG. 40 mainly includes a parallel link mechanism and an attitude control drive source for driving the parallel link mechanism.

In the link actuating device shown in FIG. 40, the parallel link mechanism and the attitude control drive source are mechanically connected in the direction along the rotation center axis 12.

Two attitude control drive sources 95a and 95b are fixed to the base end side link hub 1. The attitude control drive sources 95a and 95b are connected to the rotating bodies 2a and 2b so as to be able to transmit the driving force via the rotation transmitting members 97a and 97b and the bevel gears 98a and 98b, respectively. In FIG. 40, the attitude control drive source 95b is not shown.

The attitude control drive source 95a is arranged on the first circumference centered on the rotation center axis 12 in a plan view. The attitude control drive source 95b is arranged on a second circumference centered on the rotation center axis 12 and having a radius longer than the first circumference in a plan view.

The attitude control drive sources 95a and 95b include a rotating shaft, respectively, and bevel gears 98a and 98b are connected to the ends of the rotating shafts. Further, the rotation transmitting members 97a and 97b are fixed to the surfaces of the rotating bodies 2a and 2b facing the proximal end side. The rotation transmission members 97a and 97b are annular members and have a bevel gear portion on one surface in the axial direction thereof. As a method of fixing the rotation transmitting members 97a and 97b to the rotating bodies 2a and 2b, any method can be adopted as long as the required strength and accuracy can be obtained. For example, the rotation transmission members 97a and 97b may be fixed to the rotating bodies 2a and 2b by a method such as adhesion, press fitting, or caulking.

The bevel gears of the rotation transmission members 97a and 97b mesh with the bevel gears 98a and 98b connected to the rotation shafts of the attitude control drive sources 95a and 95b. By rotating the rotation shafts of the attitude control drive sources 95a and 95b, the bevel gears 98a and 98b and the rotation transmission members 97a and 97b rotate, and as a result, the rotating bodies 2a and 2b can be rotationally driven.

When the rotating bodies 2a and 2b are rotated by the attitude control drive sources 95a and 95b, the position of the link mechanism 11 around the rotation center axis 12 is changed. As a result, the posture of the tip side link hub 3 can be changed.

In the link operating device according to the tenth embodiment, the parallel link mechanism and the attitude control drive source may be magnetically connected in the direction along the rotation center axis 12. That is, the transmission mechanism for transmitting the driving force from the attitude control drive source to the parallel link mechanism in the link operating device according to the tenth embodiment has basically the same configuration as that in the link operating device according to the eighth embodiment. You may be. In the link actuating device according to the tenth embodiment, a magnet (not shown) fixed to the rotating bodies 2a and 2b and a stator coil (not shown) fixed to the base end side link hub 1 face each other in a direction along the rotation center axis 12. It may be different from the link actuating device according to the eighth embodiment in that it is arranged so as to do so.

Further, the link operating device according to the tenth embodiment may further include a rotation amount detecting mechanism (not shown) for detecting the rotation amount of the rotating bodies 2a and 2b. Such a rotation amount detection mechanism may have basically the same configuration as the rotation amount detection mechanism of the link actuating device shown in FIG. 37. Each detection unit is fixed to, for example, a surface of the rotating bodies 2a and 2b facing the proximal end side. Further, each detection unit may be fixed to, for example, the outer ring of the bearing 99a, the inner ring of the bearing 99b, or the surface facing the base end side of the outer ring. Each detection unit is fixed to, for example, a base end side link hub 1, and has facing portions arranged so as to face each other with an end portion located on the base end side of each detected portion in the radial direction. ing.

It should be considered that each embodiment disclosed this time is an example in all respects and is not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope of the claims.

1 base end side link hub, 2a, 2b rotating body, 2z driven rotating body, 3 tip side link hub, 4a-4c first link member, 6a-6c second link member, 7,17 bolt, 8,18 nut, 9,69 washer, 11 link mechanism, 12 rotation center shaft, 15a to 15c first center shaft, 16a to 16c second center shaft, 19,29 rotation resistance reduction member, 22a, 22b protrusion, 25a to 25c first rotation Paired part, 26a to 26c 2nd rotation paired part, 27a, 27b through hole, 28a, 28b connection part, 30 spherical link center point, 31 tip side link hub center axis, 33 shim, 35a, 35b, 95a, 95b attitude control Drive source, 36a, 36b fixed part, 37a, 37b rotation transmission member, 38 gear, 39,49,59 bearing, 46,47 fixing member, 48a, 48b rotation transmission part, 58 pulley, 60 arrow, 65,75a, 75b yoke part, 66a, 66b, 76a, 76b teeth part, 67a, 67b, 77a, 77b magnet, 68a, 68b, 78a, 78b stator coil, 70 protrusion, 71 holding member, 81a, 81b, 83a, 83b to be detected. Unit, 84a detection unit, 98a, 98b bevel gear.

Claims (14)

With the base end side link hub,
With two or more linkages,
Two or more driveable rotating bodies connected to at least one of the two or more link mechanisms,
Equipped with a link hub on the tip side,
The two or more rotating bodies are rotatably connected to the base end side link hub.
Each of the two or more link mechanisms
The first link member and
The first link member includes a second link member rotatably connected at the first rotational pair even portion.
The second link member is rotatably connected to the tip end side link hub at a second rotation paired pair portion.
The first link member of the at least one link mechanism is fixed to the two or more rotating bodies.
In the two or more link mechanisms, the first central axis of the first rotation paired portion and the second central axis of the second rotating paired portion intersect at a spherical link center point.
The rotation center axes of the two or more rotating bodies intersect with the spherical link center point,
A parallel link mechanism in which the number of the two or more rotating bodies is smaller than the number of degrees of freedom in the posture of the front end side link hub. The two or more rotating bodies are two rotating bodies.
The two or more link mechanisms are two link mechanisms.
The parallel link mechanism according to claim 1, wherein the posture of the front end side link hub has three degrees of freedom. The two rotating bodies are rotatably connected to the base end side link hub in a state where the two rotating bodies are arranged side by side so that their respective rotation center axes coincide with each other.
The parallel link mechanism according to claim 2, wherein the first link member of each of the two link mechanisms is fixed to one of the two rotating bodies. The parallel link mechanism according to claim 3, wherein the two rotating bodies are laminated so that their respective rotation center axes coincide with each other. An annular through hole is formed in the two rotating bodies so as to surround the rotation center axis.
The two rotating bodies include a first rotating body and a second rotating body arranged on the side where the base end side link hub is located when viewed from the first rotating body.
The parallel link mechanism according to claim 4, wherein the first link member connected to the second rotating body passes through the inside of the through hole of the first rotating body and extends toward the tip side link hub side. The parallel link mechanism according to claim 4 or 5, wherein at least one of the first rotation paired portion and the second rotating paired portion includes a bearing. The two rotating bodies are provided in an annular shape, and the two rotating bodies are provided in an annular shape.
The inner diameters of the two rotating bodies are provided so as to be different from each other.
The parallel link mechanism according to claim 3, wherein the two rotating bodies are arranged side by side in the radial direction with respect to the rotation center axis so that the rotation center axes coincide with each other. The parallel link mechanism according to any one of claims 1 to 7.
A link actuating device comprising a drive source for attitude control that rotates the two or more rotating bodies and arbitrarily changes the posture of the tip end side link hub with respect to the base end side link hub. The link operating device according to claim 8, wherein the two or more rotating bodies and the attitude control drive source are mechanically connected. A rotation transmission member connected to the two or more rotating bodies is provided.
The link actuating device according to claim 9, wherein the attitude control drive source rotates the two or more rotating bodies via the rotation transmitting member. The two or more rotating bodies include a rotation transmitting portion.
The link actuating device according to claim 9, wherein the attitude control drive source rotates the two or more rotating bodies via the rotation transmission unit. The link operating device according to claim 8, wherein the two or more rotating bodies and the attitude control drive source are magnetically connected. The two or more rotating bodies include magnets.
The link actuating device according to claim 8, wherein the attitude control drive source includes a coil arranged so as to face the magnet in the radial direction with respect to the rotation center axis. The link operating device according to any one of claims 8 to 13, further comprising a rotation amount detecting mechanism for detecting the rotation amount of the two or more rotating bodies.

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