CN107781369A - Rotate linear drive apparatus - Google Patents

Abstract

The invention relates to a rotary linear drive device. The rotary linear drive device has a rack shaft, a first gear, a first support member, a first motor, a second motor, a pinion, and a transmission member. The first gear is penetrated by the rack shaft, and the first gear can rotate around the rack shaft relative to the rack shaft. The first support member passes through the rack shaft and the first gear, and is rotatable around the rack shaft relative to the first gear. The transmission member is supported by the first support member, and the transmission member can transmit the rotational force of the first gear to the pinion. The rack shaft is rotatable around the rack shaft via the first support member by the driving force of the first motor. The rack shaft can move in the extension direction via the first gear, the transmission member, and the pinion under the driving force of the second motor.

Description

Rotary linear drive

technical field

The invention relates to a rotary linear drive device.

Background technique

There is a rotary linear drive device capable of rotating around an axis and capable of moving in an axial direction. The device described in Japanese Patent Laid-Open Publication No. 141464 of 1998 includes a spline shaft, a spline bearing, and a spur gear. The splined shaft has axially extending teeth. The spline bearing guides the spline shaft in the axial direction of the spline shaft. The spur gear is set to be perpendicular to the axial direction of the spline shaft, and the teeth of the spur gear mesh with the teeth of the spline shaft. When the spur gear rotates, the spline shaft moves linearly along the axial direction with the spline bearing as the guide. When the spline bearing rotates, the spline shaft rotates together with the spline bearing. The spur gears are curved along the outer diameter of the teeth in such a way that they do not interfere with the teeth of the spline shaft when the spline bearing rotates. When the spur gear and the spline bearing rotate simultaneously, the spline shaft moves linearly by means of the spur gear, and the spline shaft rotates together with the spline bearing.

In the device, in order that the teeth of the spline shaft do not interfere with the spur gear when the spline bearing rotates, the spur gear is bent along the outer diameter of the teeth of the spline shaft. Therefore, the device needs to have high precision in each component such as the spur gear and the spline shaft, resulting in an increase in cost.

Contents of the invention

An object of the present invention is to provide a rotary linear drive device capable of rotating around an axis and moving linearly in an axial direction without requiring high precision of each component.

The rotary linear drive device of technical solution 1 is capable of rotating the shaft member around the shaft and moving the shaft member in the axial direction, wherein the shaft member is a rack shaft having The rack teeth distributed in the extending direction, the rotary linear drive device includes: a first gear through which the rack shaft passes, and the first gear can rotate around the rack shaft relative to the rack shaft; a support member through which the rack shaft and the first gear pass, and the first support member can rotate around the rack shaft relative to the first gear; a first motor which can make the A first support member rotates around the rack shaft; a second motor capable of rotating the first gear relative to the rack shaft around the rack shaft; a pinion driven by the first support member supported and meshed with the rack teeth of the rack shaft; and a transmission member supported by the first support member and capable of transmitting the rotational force of the first gear to the small gear, when the first motor is driven, along with the rotation of the first supporting member, the transmission member and the pinion rotate around the rack shaft, and the rack shaft is together with the pinion Rotating around the rack shaft, when the second motor is driven, the pinion gear rotates through the transmission member along with the rotation of the first gear, and the rack shaft moves in the extending direction.

The rotary linear drive device of technical solution 1 can rotate the first support member around the rack shaft under the driving force of the first motor, and rotate the rack shaft around the rack shaft through the first support member. The rotary linear drive device rotates the first gear under the driving force of the second motor, and transmits the rotational force of the first gear to the pinion through the transmission member, so that the rack shaft can be moved along the tooth axis relative to the first support member. The bar axis moves in a straight line. Therefore, the rotary linear drive device can rotate the rack shaft around the rack shaft and linearly move the rack shaft along the axial direction of the rack shaft without requiring high precision of each component. The rotary linear drive device can use common parts such as rack shaft, pinion and motor to realize rotation and linear movement. Compared with the previous devices, the rotary linear drive device does not require high precision of each part, so the cost is relatively low. Low.

In the rotary linear drive device of technical solution 2, it is also possible that the first gear is a bevel gear, and the transmission member includes: a second gear that is a bevel gear meshed with the first gear; a third gear , which is a spur gear meshing with the pinion gear; and a rotation shaft provided so that the second gear and the third gear can be integrally rotated coaxially, and the first support member rotates with the rotation shaft One end portion of the rotation shaft is rotatably supported. The rotary linear drive device can constitute the transmission member relatively simply.

In the rotary linear drive device according to claim 3, a second support member may be further provided, the second support member has a cylindrical portion through which the rack shaft passes, and the second support member is positioned relative to the A side of the transmission member opposite to the side where the first gear is located is fixed to the first support member, and the second support member supports the other end of the rotation shaft. In the rotary linear drive device, the rotation of the second gear and the third gear can be stabilized compared to the case where the rotary shaft is supported at only one end. Therefore, rotating the linear drive device can smoothly move the first supporting member around the rack shaft.

In the rotary linear drive device according to claim 4, the first gear may be a helical gear, and the transmission member may be a helical gear meshing with the helical gear and the pinion. The rotary linear drive device can constitute the transmission member relatively simply.

In the rotary linear drive device according to claim 5, an eccentric shaft may be further provided, and the eccentric shaft supports the pinion gear at the axial center portion and supports both axial ends of the eccentric shaft at the first support member. The central portion in the axial direction is eccentric with respect to the two end portions in the axial direction. The operator can easily adjust the clearance between the rack shaft and the pinion by using the eccentric shaft. Therefore, the rotary linear drive device can reduce the rattling of the rack shaft in the rotational direction, compared with a device in which the backlash cannot be adjusted.

In the rotary linear drive device according to claim 6, there may be two sets of the pinion gears and two sets of the transmission members, the two sets of the pinion gears are arranged symmetrically with respect to the rack axis, and the two sets of pinions The transmission member is arranged symmetrically with respect to the rack axis. By making two sets of pinions symmetrical with respect to the rack axis and two sets of transmission members symmetrical with respect to the rack axis, the rotary linear driving device can reduce the number of transmissions in the gear compared to the case where the pinion and the transmission member are set as one set. Play occurs between the rack shaft and pinion. Therefore, turning the linear drive device can increase the rigidity of the rack shaft with respect to rotation.

In the rotary linear drive device according to claim 7, the two sets of pinion gears may mesh with the rack shaft at mutually different phases. The two sets of pinions of the rotary linear drive mesh with the rack shaft at mutually different phases, so that the rotary linear drive can further reduce resulting shaking.

In the rotary linear drive device according to claim 8, a bearing may be further provided, and the first support member may rotatably support the bearing, and the bearing may be arranged at a position relative to the rack shaft. The bearing is in contact with the rack shaft at a position symmetrical to the pinion. Compared with the case where no member is provided at a position symmetrical to the pinion with respect to the rack shaft, the rotary linear drive device can suppress the rack shaft from deflecting at the position where the rack shaft meshes with the pinion.

Description of drawings

FIG. 1 is a perspective view of a multi-joint robot arm device 15 .

FIG. 2 is a front view of the articulated robot arm device 15 .

FIG. 3 is a perspective view of the rotary linear drive mechanism 16 .

FIG. 4 is a perspective view of the rotary linear drive mechanism 16 .

FIG. 5 is a cross-sectional view of the rotary linear drive device 1 viewed along the line A-A in FIG. 1 .

FIG. 6 is an enlarged view of a main part of FIG. 5 .

FIG. 7 is a cross-sectional view showing the meshing of the rack shaft 2 with the pinion 7 and the pinion 8 .

FIG. 8 is a sectional view of the rotary linear drive mechanism 16 along the line B-B in FIG. 1 .

FIG. 9 is a cross-sectional view of the rotary linear drive mechanism 16 viewed along the line C-C in FIG. 5 .

FIG. 10 is a perspective view of a rotary linear drive mechanism 50 according to the second embodiment.

FIG. 11 is a cross-sectional view of the rotary linear drive mechanism 50 viewed along the line D-D in FIG. 10 .

FIG. 12 is a cross-sectional view of the rotary linear drive mechanism 50 viewed along the line E-E in FIG. 10 .

FIG. 13 is a perspective view of a rotary linear drive mechanism 60 according to a third embodiment.

FIG. 14 is a cross-sectional view of the rotary linear drive mechanism 60 viewed along the line F-F in FIG. 13 .

FIG. 15 is a cross-sectional view of the rotary linear drive mechanism 60 viewed along the line G-G in FIG. 13 .

Detailed ways

The rotary linear drive devices according to the first to third embodiments of the present invention will be described. In the following description, up and down, left and right, and front and rear indicated by arrows in the drawings are used. The same code|symbol is attached|subjected to the component common to 1st - 3rd embodiment.

The articulated robot arm device 15 of the first embodiment shown in FIGS. 1 and 2 is an industrial robot, and is a device for conveying workpieces. The articulated robot arm device 15 has an arm portion 11 , an arm portion 12 , a support portion 13 , and a base portion 14 . The arm portion 11 has a rotary linear drive device (hereinafter referred to as "device") 1 . The device 1 has a rotary linear drive 16 , a first motor 5 and a second motor 6 , wherein the rotary linear drive 16 has a rack shaft 2 . The device 1 can use the first motor 5 as a driving source to rotate the rack shaft 2 around the rack shaft 2 . The device 1 can use the second motor 6 as a driving source to move the rack shaft 2 along the extending direction of the rack shaft 2 . The extending direction of the rack shaft 2 is the up-down direction. Around the rack shaft 2 means a clockwise direction or a counterclockwise direction centering on the axis M on a plane perpendicular to the axis M of the rack shaft 2 (see FIG. 5 ). The rack shaft 2 has, for example, a holding mechanism for holding a workpiece at its lower end. The device 1 drives the second motor 6 to move the workpiece up and down while the gripping mechanism is holding the workpiece, and drives the first motor 5 to rotate the workpiece. The arm portion 12 extends in the left-right direction, and supports the right end of the arm portion 11 at its left end so that the arm portion 11 can turn. The support portion 13 extends in the vertical direction, and supports the right end of the arm portion 12 at its upper end so that the arm portion 12 can turn. The base portion 14 has a plate shape extending horizontally, and the base portion 14 is connected to the lower end of the support portion 13 . The base part 14 fixes the multi-joint robot arm device 15 on a plane. The articulated robot arm device 15 can move the workpiece in the horizontal direction by rotating the arm 11 and the arm 12 respectively.

As shown in Figures 3 to 9, in addition to the rack shaft 2, the rotary linear drive mechanism 16 also has a first gear 3, a first support member 4, a pinion 7, a pinion 8, a transmission member 9, a transmission member 10. Hereinafter, each member included in the rotary linear drive mechanism 16 will be described with reference to the posture in which the pinion gear 8 is located on the right. In the drawings other than FIG. 7 , illustration of the teeth of the rack shaft 2 , the pinion 7 , the pinion 8 , the transmission member 9 , and the transmission member 10 is omitted. As shown in FIG. 7 , the rack shaft 2 has rack teeth 21 and rack teeth 22 distributed along the extending direction on the outer periphery. The rack teeth 21 and the rack teeth 22 are arranged symmetrically with respect to the axis M of the rack shaft 2 . As shown in FIGS. 6 and 8 , the first gear 3 has a hole 47 penetrating in the vertical direction. The rack shaft 2 is passed through the hole 47 of the first gear 3 , so that the first gear 3 can rotate around the rack shaft 2 relative to the rack shaft 2 . The first gear 3 is a bevel gear. The lower end portion 40 of the first gear 3 extends downward along the rack shaft 2 .

As shown in FIGS. 3 to 6 and 8 , the first support member 4 is a cylindrical member having a hole 48 penetrating in the vertical direction. The rack shaft 2 and the first gear 3 pass through the hole 48 of the first support member 4 , and the first support member 4 can rotate around the rack shaft 2 relative to the first gear 3 . As shown in FIGS. 6 and 8 , the upper end portion of the first support member 4 is connected to a second support member 42 described later. The second support member 42 is cylindrical, and the second support member 42 is fitted in the hole 48 at the upper end portion of the first support member 4 . The lower end portion 39 of the first support member 4 extends downward along the rack shaft 2 . The first gear 3 penetrates through the lower end portion 39 , and the lower end portion 40 of the first gear 3 is positioned below the lower end portion 39 .

The pinion 7 , the pinion 8 , the transmission member 9 , and the transmission member 10 are provided inside the peripheral wall of the first support member 4 and in a space between the second support member 42 and the first gear 3 . The pinion 7 and the pinion 8 are rotatably supported by the first support member 4 . The rotation axes of the pinion 7 and the pinion 8 intersect (three-dimensionally) the axis M of the rack shaft 2 and extend in the front-rear direction. As shown in FIG. 7 , the pinion 7 meshes with the rack teeth 21 of the rack shaft 2 , and the pinion 8 meshes with the rack teeth 22 . The positions of the rack teeth 21 and the rack teeth 22 in the vertical direction are the same. As shown in FIGS. 8 and 9 , the transmission member 9 and the transmission member 10 are supported by the first support member 4 . The transmission member 9 transmits the rotational force of the first gear 3 to the pinion 7 , and the transmission member 10 transmits the rotational force of the first gear 3 to the pinion 8 . The transmission member 9 has a second gear 23 , a rotation shaft 25 , and a third gear 27 , and the transmission member 10 has a second gear 24 , a rotation shaft 26 , and a third gear 28 . The second gear 23 and the second gear 24 are bevel gears. The second gear 23 meshes with the first gear 3 , and the second gear 24 meshes with the first gear 3 . The rotating shaft 25 and the rotating shaft 26 are rod-shaped members extending parallel to the rotating shafts of the pinion 7 and the pinion 8 . The rotating shaft 25 fixes the second gear 23 , and the first support member 4 supports one end of the rotating shaft 25 so that the rotating shaft 25 can rotate. The rotating shaft 26 fixes the second gear 24 , and the first support member 4 supports one end of the rotating shaft 26 so that the rotating shaft 26 is rotatable. One end of each of the rotating shaft 25 and the rotating shaft 26 is an end on a side away from the axis M of the rack shaft 2 . The third gear 27 and the third gear 28 are spur gears. The third gear 27 is coaxially fixed to the other end side of the rotating shaft 25 with the second gear 23 , and the third gear 27 meshes with the pinion 7 . The second gear 23 and the third gear 27 can rotate integrally. The third gear 28 is coaxially fixed to the other end side of the rotating shaft 26 with the second gear 24 , and the third gear 28 meshes with the pinion 8 . The second gear 24 and the third gear 28 can rotate integrally. The device 1 has two sets of pinions, pinion 7 , pinion 8 , and two sets of transmission members, transmission member 9 , transmission member 10 . As shown in FIG. 6 , the pinion 7 and the pinion 8 are symmetrical with respect to the rack shaft 2 . As shown in FIG. 8 , the transmission member 9 and the transmission member 10 are arranged symmetrically with respect to the rack shaft 2 . As shown in FIG. 7 , the pinion 7 and the pinion 8 mesh with the rack shaft 2 at mutually different phases. That is, when the pinion 7 is in contact with the upper surface of the rack teeth 21, the position of the pinion 8 and the rack teeth 22 in the vertical direction is the same as that of the rack teeth 21. Surface contact on the underside. The first support member 4 has an opening in a portion of the peripheral wall of the first support member 4 that faces the pinion 7 and the pinion 8 . The opening can prevent each member such as the pinion 7 , the pinion 8 , the transmission member 9 , and the transmission member 10 inside the first support member 4 from interfering with the first support member 4 .

As shown in FIGS. 5 , 6 , 8 , and 9 , the device 1 further includes a support member 41 , an accommodating portion 80 , a bearing 49 , a bearing 82 , a bearing 83 , a second support member 42 , an eccentric shaft 45 , and an eccentric shaft 46 . The supporting member 41 is a plate-shaped member extending substantially parallel to the horizontal plane. The supporting member 41 serves to support the first motor 5 and the second motor 6 . The left end of the support member 41 is connected to the storage portion 80 . The accommodating part 80 accommodates the rotary linear drive mechanism 16 inside so that the rotary linear drive mechanism 16 can rotate. The accommodating portion 80 has a hole 81 penetrating up and down, and the accommodating portion 80 accommodates the rotary linear drive mechanism 16 in a state where the rack shaft 2 is passed through the hole 81 . The lower end portion of the housing portion 80 protrudes radially inward from the inner peripheral surface of the hole 81 . The bearing 49 is provided between the outer peripheral surface of the lower end portion 40 of the first gear 3 and the inner peripheral surface of the lower end portion 39 of the first support member 4 . The bearing 82 is provided at the upper end of the storage part 80 , the bearing 83 is provided at the lower end of the storage part 80 , and the bearing 82 and the bearing 83 are fitted in the inner peripheral surface of the hole 81 . The housing portion 80 supports the first support member 4 through bearings 82 and 83 so that the first support member 4 is rotatable. The first motor 5 and the second motor 6 are stepping motors. The first motor 5 is capable of rotating the first support member 4 around the rack shaft 2 . The output shaft 35 of the first motor 5 extends parallel to the direction in which the rack shaft 2 extends, and extends below the support member 41 . A pulley 37 is provided on the output shaft 35 . The belt 33 is provided between the pulley 37 and the pulley 31 . The pulley 31 is connected to the lower end portion 39 of the first support member 4 . The rack shaft 2 passes through the inner side of the pulley 31 . The second motor 6 can rotate the first gear 3 around the rack shaft 2 relative to the rack shaft 2 . The output shaft 36 of the second motor 6 extends parallel to the direction in which the rack shaft 2 extends, and extends below the support member 41 . A pulley 38 is provided on the output shaft 36 . The belt 34 is located below the belt 33 , and the belt 34 is stretched between the pulley 38 and the pulley 32 . The pulley 32 is fixed to the lower end portion 40 of the first gear 3 . The rack shaft 2 passes through the inner side of the pulley 32 . The pulley 32 is provided below the pulley 31 .

As shown in FIGS. 6 and 8 , the second support member 42 has a cylindrical portion 43 through which the rack shaft 2 penetrates. The second supporting member 42 is, for example, a ball bush or a sliding bearing. The second support member 42 is rotatable together with the rack shaft 2 , and supports the rack shaft 2 in a movable manner relative to the rack shaft 2 . The second support member 42 is embedded in the hole 48 of the first support member 4 on the side opposite to the side where the first gear 3 is located with respect to the transmission member 9 and the transmission member 10, and the second support member 42 is fixed to the second support member 42. A support member 4 . The second support member 42 has a plate-shaped support portion 17 and a support portion 18 extending downward along the peripheral edge of the cylindrical portion 43 on the lower end side. The support portion 17 supports the other end of the rotation shaft 25 , and the support portion 18 supports the other end of the rotation shaft 26 . The other end of the rotating shaft 25 is the end of the rotating shaft 25 near the axis M of the rack shaft 2 , and the other end of the rotating shaft 26 is the end of the rotating shaft 26 near the axis M of the rack shaft 2 .

As shown in FIG. 9 , the eccentric shaft 45 supports the pinion gear 7 at its axial center portion, and both ends of the eccentric shaft 45 are supported by the first support member 4 . The eccentric shaft 45 can be fixed to the first support member 4 by bringing the tip of a fixing screw screwed into the first support member 4 into contact with the eccentric shaft 45 from the radially outer side. The axial central portion of the eccentric shaft 45 is eccentric with respect to the axial end portions. When the fixing screw is loosened and turned while the eccentric shaft 45 is supported by the first support member 4 , the position of the pinion 7 changes. Therefore, the distance between the rack shaft 2 and the pinion 7 can be adjusted. The eccentric shaft 46 supports the pinion gear 8 at its axial center, and both ends of the eccentric shaft 46 are supported by the first support member 4 . The eccentric shaft 46 can be fixed to the first support member 4 by bringing the tip of a fixing screw screwed into the first support member 4 into contact with the eccentric shaft 46 from the radially outer side. The axial center portion of the eccentric shaft 46 is eccentric from both end portions. When the fixing screw is loosened and rotated while the eccentric shaft 46 is supported by the first support member 4 , the position of the pinion 8 changes. Therefore, the distance between the rack shaft 2 and the pinion 8 can be adjusted. The operator can adjust the distance between the rack shaft 2 and the pinion 7 and the distance between the rack shaft 2 and the pinion 7 by inserting a tool into the grooves formed at the ends of the eccentric shaft 45 and 46 and rotating the eccentric shaft 45 and 46 . 2 and the distance between pinion 8.

The operation of the device 1 of the first embodiment will be described. The device 1 drives the first motor 5 when the rack shaft 2 is to be rotated around the rack shaft 2 . The rack shaft 2 is rotatable around the rack shaft 2 via the first support member 4 by the driving force of the first motor 5 . That is, when the device 1 drives the first motor 5 , the first support member 4 rotates via the pulley 37 , the pulley 31 , and the belt 33 . With the rotation of the first support member 4 , the transmission member 9 , the transmission member 10 , the pinion 7 , and the pinion 8 supported by the first support member 4 also rotate around the rack shaft 2 . Therefore, the rack shaft 2 rotates around the rack shaft 2 together with the pinion 7 and the pinion 8 . That is, when the first support member 4 rotates, the rack shaft 2 rotates around the rack shaft 2 in the housing portion 80 together with the first support member 4 .

When the device 1 is to move the rack shaft 2 in the vertical direction along the axis M, the second motor 6 is driven. The rack shaft 2 can move relative to the first supporting member 4 in the extension direction via the first gear 3 , the transmission member 9 , the transmission member 10 , the pinion 7 , and the pinion 8 under the driving force of the second motor 6 . That is, when the device 1 drives the second motor 6 , the first gear 3 rotates around the rack shaft 2 relative to the rack shaft 2 via the pulley 38 , the pulley 32 , and the belt 34 . When the first gear 3 rotates, the pinion 7 rotates by means of the second gear 23 , the rotating shaft 25 and the third gear 27 . When the first gear 3 rotates, the pinion 8 rotates by means of the second gear 24 , the rotating shaft 26 and the third gear 28 . The rack shaft 2 moves upward or downward relative to the first support member 4 according to the rotation directions of the pinion 7 and the pinion 8 . The device 1 can not only perform rotation and linear movement separately at different timings, but also can perform rotation and linear movement at the same time.

In the rotary linear drive device 91 of the articulated robot arm device 90 of the second embodiment, a rotary linear drive mechanism 50 is provided instead of the rotary linear drive mechanism 16 of the device 1 of the first embodiment, and other structures are the same as those of the first embodiment. Device 1 is the same. As shown in FIGS. 10 to 12 , the rotary linear drive mechanism 50 has a rack shaft 52 , a first gear 3 , a first support member 4 , a pinion 7 , and a transmission member 9 . In the rotary linear drive mechanism 50 of the second embodiment, a rack shaft 52 and a bearing 51 are provided instead of the rack shaft 2 , the pinion 8 , and the transmission member 10 of the rotary linear drive mechanism 16 of the first embodiment. The description of the same structure as that of the device 1 of the first embodiment is omitted, and the rack shaft 52 and the bearing 51 which are different from those of the first embodiment will be described.

As shown in FIG. 11 , the rack shaft 52 has rack teeth 53 distributed along the extending direction on the outer periphery. The extending direction of the rack shaft 52 is the up-down direction. The rack teeth 53 mesh with the pinion 7 . The bearing 51 is rotatably supported by the first support member 4 and is arranged at a position symmetrical to the pinion 7 with respect to the rack shaft 52 . The rotation axis of the bearing 51 intersects (stereoscopically) the direction in which the rack shaft 52 extends, and is parallel to the rotation axis of the pinion 7 . The bearing 51 is in contact with the rack shaft 52 . The surface of the rack shaft 52 that contacts the bearing 51 is a flat or curved surface, and does not have rack teeth. The bearing 51 may be rotatably supported by the first support member 4 via the eccentric shaft 46 .

The operation of the device 91 of the second embodiment will be described. The device 91 drives the first motor 5 when the rack shaft 52 is to be rotated around the rack shaft 52 . The rack shaft 52 is rotatable around the rack shaft 52 via the first support member 4 by the driving force of the first motor 5 as in the device 1 of the first embodiment. The device 91 drives the second motor 6 when the rack shaft 52 is to be moved along the axis M in the direction in which the rack shaft 52 extends. The rack shaft 52 can move relative to the first supporting member 4 along the extending direction of the rack shaft 52 by the driving force of the second motor 6 via the first gear 3 , the transmission member 9 , and the pinion 7 . That is, when the device 91 drives the second motor 6 , the first gear 3 rotates around the rack shaft 52 relative to the rack shaft 52 via the pulley 38 , the pulley 32 , and the belt 34 . When the first gear 3 rotates, the pinion 7 rotates by means of the second gear 23 , the rotating shaft 25 and the third gear 27 . The rack shaft 52 moves upward or downward relative to the first support member 4 according to the rotation direction of the pinion 7 . When the rack shaft 52 moves relative to the first support member 4 , the bearing 51 contacts the rack shaft 52 without interfering with the movement of the rack shaft 52 .

In the rotary linear drive device 96 of the articulated robot arm device 95 of the third embodiment, a rotary linear drive mechanism 60 is provided instead of the rotary linear drive mechanism 16 of the device 1 of the first embodiment, and the other structures are the same as those of the first embodiment. The device 1 is the same. As shown in FIGS. 13 to 15 , the rotary linear drive mechanism 60 of the third embodiment has a rack shaft 61, a first gear 62, a first support member 72, a pinion 65, a pinion 66, a transmission member 63, a transmission member 64. The rack shaft 61 has rack teeth 74 and 75 distributed along the extending direction on the outer periphery. The extending direction of the rack shaft 61 is the up-down direction. The rack teeth 74 and the rack teeth 75 are arranged symmetrically with respect to the axis M of the rack shaft 61 . The first gear 62 has teeth meshing with the transmission member 63 and the transmission member 64 , and has a lower end portion 77 below the first gear 62 , and the diameter of the lower end portion 77 is smaller than that of the first gear 62 having teeth. The first gear 62 has a hole 78 penetrating in the vertical direction. The rack shaft 61 is passed through the hole 78 of the first gear 62 , so that the first gear 62 can rotate around the rack shaft 61 relative to the rack shaft 61 . The first gear 62 is a helical gear.

The first support member 72 is a cylindrical member having a hole 87 penetrating in the vertical direction. By passing the rack shaft 61 and the first gear 62 through the hole 87 of the first support member 72 , the first support member 72 can rotate around the rack shaft 61 relative to the first gear 62 . The upper end portion of the first support member 72 is connected to the second support member 73 which is the same as the second support member 42 of the first embodiment. The lower end portion 76 of the first support member 72 extends along the rack shaft 61 . The bearing 79 is provided between the outer peripheral surface of the lower end portion 77 of the first gear 62 and the inner peripheral surface of the lower end portion 76 of the first supporting member 72 . The pulley 67 is fixed to the lower end portion 76 of the first support member 72 . The belt 33 in FIG. 5 is provided between the pulley 37 and the pulley 67 . The first motor 5 is capable of rotating the first support member 72 around the rack shaft 61 . The rack shaft 61 passes through the inner side of the pulley 67 . The pulley 68 is fixed to the lower end portion 77 of the first gear 62 . The pulley 67 is provided between the pulley 68 and the first support member 72 . The belt 34 is provided between the pulley 38 and the pulley 68 . The second motor 6 can rotate the first gear 62 around the rack shaft 61 relative to the rack shaft 61 . The rack shaft 61 passes through the inner side of the pulley 68 .

As shown in FIGS. 13 and 14 , the pinion gear 65 and the pinion gear 66 are supported by the first support member 72 . The rotation axes of the pinion gear 65 and the pinion gear 66 cross the axis M of the rack shaft 61 and extend in the front-rear direction. The pinion 65 meshes with the rack teeth 74 of the rack shaft 61 , and the pinion 66 meshes with the rack teeth 75 . The pinion 65 and the pinion 66 are helical gears, and the rack teeth 74 and 75 are the teeth of the helical rack. The transmission member 63 and the transmission member 64 are helical gears. The transmission member 63 meshes with the first gear 62 , and the transmission member 64 meshes with the first gear 62 . The transmission member 63 transmits the rotational force of the first gear 62 to the pinion 65 , and the transmission member 64 transmits the rotational force of the first gear 62 to the pinion 66 . Device 96 has two sets of pinions, pinion 65 , pinion 66 , and two sets of transmission members, transmission member 63 , transmission member 64 . The pinion gear 65 and the pinion gear 66 are arranged symmetrically with respect to the rack shaft 61 . The transmission member 63 and the transmission member 64 are arranged symmetrically with respect to the rack shaft 61 . The rotation axes of the pinion gear 65 and the pinion gear 66 are parallel to the rotation axes of the transmission member 63 and the transmission member 64 . The pinion gear 65 and the pinion gear 66 can mesh with the rack shaft 61 at mutually different phases. The rotation shafts of the pinion gear 65 and the pinion gear 66 may be the same eccentric shafts as those of the eccentric shaft 45 and the eccentric shaft 46 .

The operation of the device 96 of the third embodiment will be described. The device 96 drives the first motor 5 when the rack shaft 61 is to be rotated around the rack shaft 61 . The rack shaft 61 is rotatable around the rack shaft 61 via the first support member 72 by the driving force of the first motor 5 as in the device 1 of the first embodiment. That is, when the device 96 rotates the first motor 5 , the first support member 72 rotates via the pulley 37 , the pulley 67 , and the belt 33 . When the first support member 72 rotates, the pinion gear 65 and the pinion gear 66 supported by the first support member 72 also rotate around the rack shaft 61 . Therefore, the rack shaft 61 rotates around the rack shaft 61 together with the pinion gear 65 and the pinion gear 66 . That is, when the first support member 72 rotates, the rack shaft 61 rotates around the rack shaft 61 together with the first support member 72 .

The device 96 drives the second motor 6 when the rack shaft 61 is to be moved along the axis M in the direction in which the rack shaft 61 extends. The rack shaft 61 can move relative to the first support member 72 along the extending direction of the rack shaft 61 via the transmission member 63 , the transmission member 64 , the pinion 65 , and the pinion 66 under the driving force of the second motor 6 . That is, when the second motor 6 rotates, the first gear 62 rotates around the rack shaft 61 relative to the rack shaft 61 via the pulley 38 , the pulley 68 , and the belt 34 . When the first gear 62 is rotated, the pinion 65 is rotated by the transmission member 63 , and the pinion 66 is rotated by the transmission member 64 . When the first gear 62 rotates, the rotation direction of the transmission member 63 and the rotation direction of the transmission member 64 viewed from the same side are different from each other. When the first gear 62 rotates, the rotation direction of the transmission member 63 and the rotation direction of the pinion gear 65 viewed from the same side are different from each other. When the first gear 62 rotates, the rotation direction of the pinion gear 65 and the rotation direction of the pinion gear 66 viewed from the same side are different from each other. The rack shaft 61 moves upward or downward relative to the first support member 72 in accordance with the rotation directions of the pinion gear 65 and the pinion gear 66 .

The device 1, the device 91, and the device 96 of the first to third embodiments described above are examples of the rotary linear drive device of the present invention. The rack shaft 2, the rack shaft 52, and the rack shaft 61 are examples of the rack shaft of the present invention. The first gear 3 and the first gear 62 are examples of the first gear of the present invention. The first support member 4 and the first support member 72 are examples of the first support member of the present invention. The first motor 5 is an example of the first motor of the present invention, and the second motor 6 is an example of the second motor of the present invention. The pinion 7, the pinion 8, the pinion 65, and the pinion 66 are examples of the pinion of the present invention. The transmission member 9, the transmission member 10, the transmission member 63, and the transmission member 64 are an example of the transmission member of this invention. The second gear 23 and the second gear 24 are examples of the second gear of the present invention. The rotating shaft 25 and the rotating shaft 26 are examples of the rotating shaft of the present invention. The third gear 27 and the third gear 28 are examples of the third gear of the present invention. The second support member 42 and the second support member 73 are examples of the second support member of the present invention. The eccentric shaft 45 and the eccentric shaft 46 are examples of the eccentric shaft of the present invention. The bearing 51 is an example of the bearing of this invention.

The device 1 of the above-mentioned first embodiment can rotate the first support member 4 around the rack shaft 2 under the driving force of the first motor 5, and through the first support member 4, the transmission member 9, the transmission member 10, The pinion 7 and the pinion 8 make the rack shaft 2 rotate around the rack shaft 2 . The device 1 rotates the first gear 3 under the action of the driving force of the second motor 6, and transmits the rotational force of the first gear 3 to the pinion 7 and the pinion 8 through the transmission member 9 and the transmission member 10, thereby enabling the gear The rack shaft 2 moves linearly along the rack shaft 2 relative to the first support member 4 . Therefore, the device 1 can rotate the rack shaft 2 around the rack shaft 2 and move the rack shaft 2 linearly in the axial direction of the rack shaft 2 without requiring high precision of each component. The device 1 can realize rotation and linear movement by using common parts such as the rack shaft 2, the pinion 7, the pinion 8, the first motor 5, and the second motor 6. Compared with the conventional devices, the device 1 does not require various parts It has higher precision and thus lower cost. In the device 1, the first motor 5 and the second motor 6 can be arranged on the same side with respect to the rack shaft 2, and the degree of freedom in design is higher than conventional ones. Compared with conventional devices, the device 1 can also increase the amount of movement along the rack shaft 2 , and an increase in the speed of the linear movement can be expected. The device 91 of the second embodiment and the device 96 of the third embodiment can exhibit the same effects as those of the device 1 of the first embodiment.

The first gear 3 of the device 1 of the first embodiment is a bevel gear. The transmission member 9 has a second gear 23 , a rotation shaft 25 , and a third gear 27 . The rotating shaft 25 is disposed on the second gear 23 . The third gear 27 is coaxially provided on the rotating shaft 25 with the second gear 23 , and the third gear 27 meshes with the pinion 7 . The transmission member 10 has a second gear 24 , a rotation shaft 26 , and a third gear 28 . The rotating shaft 26 is disposed on the second gear 24 . The third gear 28 is coaxially disposed on the rotating shaft 26 with the second gear 24 , and the third gear 28 meshes with the pinion 8 . One end of the second gear 23 and one end of the second gear 24 are rotatably supported by the first support member. The device 1 can relatively simply configure the transmission member 9 and the transmission member 10 . The device 91 of the second embodiment can exhibit the same effect as the device 1 of the first embodiment.

The first gear 62 of the device 96 of the third embodiment is a helical gear. The transmission member 63 is a helical gear that meshes with the first gear 62 and the pinion 65 . The transmission member 64 is a helical gear that meshes with the first gear 62 and the pinion 66 . The device 96 can relatively simply configure the transmission member 63 and the transmission member 64 . Compared with the device 1 of the first embodiment and the device 91 of the second embodiment, the device 96 of the third embodiment can reduce the number of parts of the transmission member.

The device 1 of the first embodiment has a second support member 42 having a cylindrical portion 43 through which the rack shaft 2 penetrates, and the second support member 42 is positioned relative to the transmission member 9 and the transmission member 10 . The side opposite to the side where the first gear 3 is located is fixed to the first support member 4 . The second supporting member 42 supports the other end portion of the rotating shaft 25 and the other end portion of the rotating shaft 26 . In the device 1 , the rotation of the second gear 23 , the second gear 24 and the third gear 27 and the third gear 28 can be stabilized compared to the case where the rotation shaft 25 and the rotation shaft 26 are supported at only one end. Therefore, the device 1 can smoothly move the first support member 4 around the rack shaft 2 .

The device 1 of the first embodiment has an eccentric shaft 45 and an eccentric shaft 46, the eccentric shaft 45 supports the pinion 7, the eccentric shaft 46 supports the pinion 8, and the eccentric shaft 45 can adjust the distance between the rack shaft 2 and the pinion 7, The eccentric shaft 46 can adjust the distance between the rack shaft 2 and the pinion 8 . Therefore, the operator can easily adjust the gap between the rack shaft 2 and the pinion 7 and the gap between the rack shaft 2 and the pinion 8 using the eccentric shaft of the device 1 . Therefore, the device 1 can reduce the rattling of the rack shaft 2 in the rotational direction, compared with a device in which the gap cannot be adjusted. The device 91 of the second embodiment has the same effect as the above-mentioned effect of the device 1 of the first embodiment.

The device 1 of the first embodiment has two sets of pinion gears, that is, a pinion gear 7 and a pinion gear 8 , and two sets of transmission members, that is, a transmission member 9 and a transmission member 10 . The two sets of pinion gears, that is, the pinion gear 7 and the pinion gear 8 are arranged symmetrically with respect to the rack shaft 2 . The transmission member 9 and the transmission member 10 are arranged symmetrically with respect to the rack shaft 2 . The device 1 sets two sets of pinion gears, that is, the pinion gear 7 and the pinion gear 8, to be symmetrical with respect to the rack shaft 2, and sets two sets of transmission members, namely, the transmission member 9 and the transmission member 10, to be symmetrical with respect to the rack shaft 2, Compared with the case where the pinion and the transmission member are set as one set, it is possible to reduce backlash generated between the rack shaft 2 and the pinion 7 and between the rack shaft 2 and the pinion 8 . Therefore, the device 1 can increase the rigidity of the rack shaft 2 with respect to rotation.

The two sets of pinion gears of the device 1 according to the first embodiment, that is, the pinion gear 7 and the pinion gear 8 mesh with the rack shaft 2 at phases different from each other. The device 1 can further reduce the rattling generated between the rack shaft 2 and the pinion 7 and between the rack shaft 2 and the pinion 8 , compared with devices meshed at the same phase.

The device 91 of the second embodiment has a bearing 51 rotatably supported by the first support member 4 , and the bearing 51 is arranged at a position symmetrical to the pinion 7 with respect to the rack shaft 52 . The bearing 51 is in contact with the rack shaft 52 . The device 91 can suppress the rack shaft 52 from being deflected at the position where the rack shaft 52 meshes with the pinion 7 compared to the case where no member is provided at a position symmetrical to the pinion 7 with respect to the rack shaft 52 .

The rotary linear drive device of the present invention can be modified in various ways other than the above-described embodiment. The rotary linear drive device 1 , the rotary linear drive device 91 , and the rotary linear drive device 96 may not be provided on the multi-joint robot arm device 15 , the multi-joint robot arm device 90 , and the multi-joint robot arm device 95 . The shape, size, and arrangement of members included in the rotary linear drive device can be appropriately changed. The first support member does not need to have an opening in the peripheral wall of the first support member. The direction in which the rack shaft extends may be a direction other than the up-down direction. That is, the linear movement direction of the rotary linear drive device can be appropriately changed. The formation position, shape, and number of rack teeth of the rack shaft can be appropriately changed. The first gear may be any gear as long as the rack shaft penetrates therethrough and is rotatable relative to the rack shaft around the rack shaft. The first support member is only required to be a member through which the rack shaft and the first gear penetrate and is rotatable around the rack shaft relative to the first gear, and its shape, size, etc. may be appropriately changed. The first motor 5 and the second motor 6 may not be arranged on the same side with respect to the rack shaft. The first motor 5 and the second motor 6 may be motors other than stepping motors. The member supporting the first motor 5 and the second motor 6 and the member accommodating the rotary linear drive mechanism may be separate members.

The arrangement and number of pinions and transmission members can be appropriately changed. There may be one set of pinion gears and transmission members, or three or more sets. When the rotary linear drive device has multiple sets of pinion gears and transmission members, the structures of the respective pinion gears and transmission members may be different from each other. When the pinion and the transmission member are in an even number, the pinion and the transmission member may be arranged symmetrically or asymmetrically with respect to the rack axis. When the pinion and the transmission member are set as one set, the bearing may not be provided at a symmetrical position with respect to the pinion. The second support member 42 of the device 1 of the second embodiment may not have the support portion 18 . The second support member of the rotary linear drive device does not need to support the other end of the rotary shaft. The pinion and the bearing do not need to be supported by the eccentric shaft. The two sets of pinions can also mesh with the rack shaft in the same phase as each other.

The rotary linear drive mechanism 60 of the third embodiment may not have the pinion gear 66 and the transmission member 64 . In this case, the rack shaft 61 may omit the rack teeth 75 , and the rack shaft 61 may contact the same bearing as the bearing 51 of the rotary linear drive mechanism 50 of the second embodiment. The surface of the rack shaft that contacts the bearing may be flat or curved.

Claims (8)

1. A rotary linear drive device (1, 91, 96) capable of rotating a shaft member around an axis and moving the shaft member in an axial direction, characterized in that, The shaft member is a rack shaft (2, 52, 61) having rack teeth distributed on the outer periphery along the extending direction of the rack shaft, The rotary linear drive consists of: a first gear (3, 62), through which the rack shaft passes, and which can rotate around the rack shaft relative to the rack shaft; a first support member (4, 72) through which the rack shaft and the first gear pass, and which can rotate around the rack shaft relative to the first gear; a first motor (5) capable of rotating said first support member about said rack shaft; a second motor (6) capable of rotating said first gear relative to said rack shaft about said rack shaft; a pinion (7, 8, 65, 66) supported by said first support member and engaged with said rack teeth of said rack shaft; and a transmission member (9, 10, 63, 64) supported by the first support member and capable of transmitting the rotational force of the first gear to the pinion, When the first motor is driven, along with the rotation of the first support member, the transmission member and the pinion rotate around the rack shaft, and the rack shaft rotates around the pinion together with the pinion. The rack shaft rotates, When the second motor is driven, the pinion gear is rotated by the transmission member along with the rotation of the first gear, and the rack shaft moves in the extending direction. 2. The rotary linear drive device according to claim 1, characterized in that, said first gear is a bevel gear, The transfer components include: a second gear (23, 24) which is a bevel gear meshing with said first gear; a third gear (27, 28) which is a spur gear meshing with said pinion; and a rotating shaft (25, 26) configured to be able to integrally rotate the second gear and the third gear coaxially, and the first supporting member supports the rotating shaft in a rotatable manner; one end. 3. The rotary linear drive device according to claim 2, characterized in that, The rotary linear drive device also has a second support member (42, 73) having a cylindrical portion through which the rack shaft passes, and the second support member is opposite to the transmission member relative to the transmission member. the side opposite to the side where the first gear is located is fixed to the first supporting member, The second support member supports the other end portion of the rotation shaft. 4. The rotary linear drive device according to claim 1, characterized in that, said first gear is a helical gear, The transmission member is a helical gear that meshes with the helical gear and the pinion. 5. The rotary linear drive device according to any one of claims 1 to 4, characterized in that, The rotary linear drive device also has eccentric shafts (45, 46) that support the pinion gear with an axial center portion and support both axial end portions of the eccentric shaft with the first supporting member. The central portion is eccentric with respect to the axial end portions. 6. The rotary linear drive device according to any one of claims 1 to 4, characterized in that: The rotary linear drive has two sets of said pinion gears and two sets of said transmission members, Two sets of the pinion gears are arranged symmetrically with respect to the rack axis, and two sets of the transmission members are arranged symmetrically with respect to the rack axis. 7. The rotary linear drive device according to claim 6, characterized in that, The two sets of pinions mesh with the rack shaft in mutually different phases. 8. The rotary linear drive device according to any one of claims 1 to 4, characterized in that, The rotary linear drive device further has a bearing (51), the first supporting member supports the bearing in a rotatable manner, and the bearing is arranged symmetrically with respect to the pinion with respect to the rack shaft. s position, The bearing is in contact with the rack shaft.