WO2023079707A1 - Rotary shaft structure, and machine - Google Patents

Abstract

Conventionally, there has been a demand for a technology that, for example under the necessity of downsizing a rotary shaft structure, enables wiring of an increased number of filament bodies within the rotary shaft structure. This rotary shaft structure 50 comprises: a hollow fixed part 136; a hollow rotary part 134 that is disposed on the fixed part 136 so as to be rotatable about a rotary axis J4 and that, together with the fixed part 136, defines a through-hole 138 which penetrates the rotary part 134 and the fixed part 136 in the direction of the rotary axis J4 and through which filament bodies 26 pass; and a restriction member 58 that restricts the filament bodies 26 in the rotary part 134 so as to allow the filament bodies 26 to rotate along with the rotary part 134 within a section A between one open end 138a and the other open end 138b of the through-hole 138.

Description

Rotating shaft structure and machine

The present disclosure relates to rotating shaft structures and machines.

A mechanical rotating shaft structure (so-called actuator) is known (for example, Patent Document 1).

JP 2017-159397 A

Conventionally, for example, under the demand for downsizing the rotating shaft structure, there has been a demand for technology that enables wiring of more filaments inside the rotating shaft structure.

The rotary shaft structure includes a hollow fixed part and a hollow rotary part provided in the fixed part so as to be rotatable around the rotation axis, and penetrates the rotary part and the fixed part in the direction of the rotation axis, a rotating portion that defines, together with the fixed portion, a through-hole through which the filament passes; and a restraining member that restrains the filamentary body to the rotating part.

According to the present disclosure, even if the rotating part rotates, the filamentous body will not be twisted inside the through-hole. Therefore, since the filaments can be densely wired inside the through-hole, a sufficient number of filaments can be wired inside the through-hole even when the rotating shaft structure is miniaturized, for example.

1 is a perspective view of a machine according to one embodiment; FIG. FIG. 2 is a cross-sectional view of the rotating shaft structure shown in FIG. 1; FIG. 3 is a view of the sensor shown in FIG. 2 as seen from the axial direction; Fig. 3 is a perspective view of a machine according to another embodiment; FIG. 5 is a cross-sectional view of the rotating shaft structure shown in FIG. 4; It is a sectional view of the rotating shaft structure concerning other embodiments. It is the figure which looked at the rotating shaft structure shown in FIG. 6 from the axial direction front side. FIG. 11 is a perspective view of a machine according to yet another embodiment;

Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. In addition, in various embodiments described below, the same reference numerals are given to the same elements, and redundant descriptions are omitted. First, referring to FIG. 1, a machine 10 according to one embodiment will be described. In this embodiment, the machine 10 is a vertical articulated robot comprising a robot base 12 , a swing trunk 14 , an upper arm 16 , a lower arm 18 and a wrist 20 . In this embodiment, each of the pivot 14, upper arm 16, forearm 18, and wrist 20 are hollow.

The robot base 12 is fixed on the work cell floor or an automated guided vehicle (AGV). The swing barrel 14 is provided on the robot base 12 so as to be rotatable around the first rotation axis J1. The first rotation axis J1 may be arranged parallel to the vertical direction. The upper arm 16 is provided on the swing barrel 14 so that its base end 16a can rotate around a second rotation axis J2 perpendicular to the first rotation axis J1.

In this embodiment, the forearm 18 has a proximal arm 22 and a distal arm 24 . The base end arm 22 includes a base portion 22a provided at the distal end portion 16b of the upper arm portion 16 so as to be rotatable around a third rotation axis J3 parallel to the second rotation axis J2, and a base portion 22a. , and a cylindrical portion 22b extending in the direction of a fourth rotation axis J4 orthogonal to the third rotation axis J3. On the other hand, the distal end arm 24 is provided on the cylindrical portion 22b so that the base end portion 24a thereof can rotate around the fourth rotation axis J4.

The wrist part 20 has a wrist base 20a and a wrist flange 20b. The wrist base 20a has a substantially L-shaped outer shape and is provided at the distal end portion 24b of the distal arm 24 so as to be rotatable around a fifth rotational axis J5 perpendicular to the fourth rotational axis J4. It is The wrist flange 20b is provided on the wrist base 20a so as to be rotatable around a sixth rotation axis J6 orthogonal to the fifth rotation axis J5.

An end effector (robot hand, welding torch, cutting tool, laser processing head, etc.) (not shown) is detachably attached to the wrist flange 20b. The machine 10 has a pivoting barrel 14, an upper arm 16, a forearm 18 (proximal arm 22, distal arm 24), and a wrist 20 (wrist base 20a, wrist flange 20b) about respective rotation axes J1-J6. By rotating the end effector, the end effector is positioned at an arbitrary position, and a predetermined work (workpiece handling, welding, cutting, laser processing, etc.) is performed on the work by the end effector.

The machine 10 further comprises a filament 26 and a rotating shaft structure 50 . The filamentary body 26 is, for example, a power line for supplying electric power to an electric motor (eg, a servo motor) built in the machine 10, a control signal line for transmitting a signal for controlling the end effector, an air tube, or the like. include.

One end of the filament 26 is connected to a controller (not shown) of the machine 10, and the other end is connected to an end effector. The striatum 26 is wired to pass through the interior of the robot base 12, swing barrel 14, upper arm 16, forearm 18, and wrist 20 and connect to the end effector.

A pivot structure 50, referred to as an actuator, is positioned between the proximal arm 22 and the distal arm 24 to rotate the distal arm 24 relative to the proximal arm 22 along a fourth axis of rotation J4. to rotate around. The rotating shaft structure 50 will be described below with reference to FIG. 2 . In the following description, the direction of the fourth rotation axis J4 is defined as the axial direction, the radial direction of a circle centered on the fourth rotation axis J4 is defined as the radial direction, and the circumferential direction of the circle is defined as the circumferential direction. do. Also, for convenience, the direction indicated by arrow D in FIG. 2 is referred to as the axial forward direction.

The rotating shaft structure 50 includes an electric motor 52, a speed reducer 54, a sensor 56, and a restraining member 58. In this embodiment, the electric motor 52, the speed reducer 54, and the sensor 56 are arranged substantially coaxially with respect to the fourth rotation axis J4, and arranged side by side in the axial direction. Electric motor 52 has housing 62 , stator 64 , rotor 66 , encoder 68 , and brake mechanism 70 .

The housing 62 has a tubular shape and houses the stator 64, the rotor 66, the encoder 68, and the brake mechanism 70 inside. Housing 62 is secured to cylindrical portion 22b of proximal arm 22 (FIG. 1). The stator 64 has a cylindrical stator core 72 fixed to the housing 62 and a coil 74 wound around the stator core 72 .

The rotor 66 is rotatably arranged radially inside the stator 64 . Specifically, the rotor 66 has a rotor shaft 76 and a rotor core 78 . The rotor shaft 76 is cylindrical and extends straight in the axial direction. Rotor shaft 76 is rotatably supported in housing 62 by annular bearings 80 and 82 .

The bearing 80 is interposed between the support wall 62a of the housing 62 and the rotor shaft 76, and the bearing 82 is interposed between the support wall 62b of the housing 62 and the rotor shaft 76. An annular oil seal 83 is interposed between the support wall 62 b and the rotor shaft 76 .

The support wall 62a is arranged on the rear side of the stator 64 and the rotor core 78 in the axial direction, while the support wall 62b is arranged on the front side of the stator 64 and the rotor core 78 in the axial direction. A space S1 that accommodates the stator 64 and the rotor core 78 is defined inside the housing 62 by the support walls 62a and 62b.

The rotor core 78 is a cylindrical member containing a plurality of magnets (not shown) arranged in the circumferential direction, and is fixed to the outer peripheral surface of the rotor shaft 76 so as to rotate integrally with the rotor shaft 76 . It is The stator 64 generates a rotating magnetic field in the circumferential direction by the voltage applied to the coil 74, thereby generating power to rotationally drive the rotor core 78 in the circumferential direction. Rotor 66 is thus rotated relative to housing 62 and stator 64 about fourth axis of rotation J4.

The encoder 68 detects rotation of the rotor 66 (for example, rotational position or rotational angle). Specifically, the encoder 68 has a rotary slit 68a, a light emitter 68b, and a light receiver 68c. The rotary slit 68a has a plurality of slits and is fixed to the outer peripheral surface of the rotor shaft 76 so as to rotate together with the rotor shaft 76. As shown in FIG. The rotating slit 68a is arranged between the light emitting portion 68b and the light receiving portion 68c.

The light emitting part 68b is fixed to the housing 62 and outputs light toward the rotating slit 68a. The light receiving portion 68c is fixed to the housing 62 and receives light output from the light emitting portion 68b. More specifically, the light output from the light emitting section 68b is patterned by passing through a slit formed in the rotating slit 68a, and enters the light receiving section 68c. The encoder 68 detects the rotation of the rotor 66 based on the patterned light received by the light receiving section 68c.

The brake mechanism 70 brakes the rotation of the rotor 66. Specifically, the brake mechanism 70 has a brake disc 70a, an end plate 70b, an armature 70c, and a brake core 70d. The brake disc 70a is fixed to the outer peripheral surface of the rotor shaft 76 so as to rotate together with the rotor shaft 76. As shown in FIG.

The end plate 70b is fixed to the brake core 70d. The armature 70c is arranged to face the end plate 70b and is provided on the brake core 70d so as to be movable in the axial direction. The brake disc 70a is arranged between the end plate 70b and the armature 70c, and the armature 70c is biased toward the brake disc 70a by a biasing member (not shown) such as a coil spring.

The brake core 70d is fixed to the housing 62, and a brake coil (not shown) is wound around the brake core 70d. When a voltage is applied to the brake coil, the brake core 70d is magnetized, whereby the armature 70c is attracted to the brake core 70d and separated from the brake disc 70a. Thus, the brake mechanism 70 releases the brake on the rotor 66 and the rotor 66 is allowed to rotate.

On the other hand, when the voltage applied to the brake coil becomes zero, the excitation of the brake core 70d is released, and the armature 70c is pressed against the brake disc 70a by the action of the biasing member. Thus, brake mechanism 70 brakes the rotation of rotor 66 . The encoder 68 and brake mechanism 70 are positioned axially rearward of the support wall 62a, and the support wall 62a and the axially rearward end wall 62c of the housing 62 allow the encoder 68 and brake mechanism to be positioned inside the housing 62. A space S2 that accommodates the mechanism 70 is defined.

The reduction gear 54 is provided on the front side in the axial direction of the electric motor 52 and reduces the rotation of the rotor 66 . Specifically, the speed reducer 54 is, for example, a planetary gear speed reducer, a strain wave gear speed reducer, or a cycloidal speed reducer, and has a housing 84 , an internal gear 86 , an external gear 88 , and an output shaft 90 . The housing 84 is cylindrical and fixed to the housing 62 of the electric motor 52 .

The internal gear 86 is arranged to surround the axial front end of the rotor shaft 76 and meshes with a gear portion formed on the axial front end. The external gear 88 is rotatably supported by the housing 84 via an annular bearing 92 , is arranged radially outward of the internal gear 86 and meshes with the internal gear 86 .

The output shaft 90 has an annular shape and is provided on the front side in the axial direction of the housing 84 so as to be rotatable around the fourth rotation axis J4. More specifically, output shaft 90 has a body portion 94 , an outer flange 96 and an inner flange 98 . The body portion 94 is connected to the external gear 88 via an output pin 95 , and the rotation of the external gear 88 is transmitted to the body portion 94 through the output pin 95 . Note that a bolt or the like may be used instead of the output pin 95 to directly connect the main body 94 and the external gear 88 .

An annular oil seal 100 is interposed between the inner peripheral surface 94 a of the body portion 94 and the rotor shaft 76 . The oil seals 83 and 100 prevent the lubricant filled inside the rotating shaft structure 50 from leaking, and prevent foreign matter from entering the rotating shaft structure 50 from the outside.

The outer flange 96 protrudes radially outward from the outer peripheral surface 94b of the body portion 94 and extends in the circumferential direction. On the other hand, the inner flange 98 protrudes radially inward from the inner peripheral surface 94a of the body portion 94 and extends in the circumferential direction. The inner flange 98 is spaced axially forward from the axial front end 76 a of the rotor shaft 76 .

The sensor 56 is arranged adjacent to the front side in the axial direction of the output shaft 90 and detects a force (for example, torque) acting on the sensor 56 . The sensor 56 will be described below with reference to FIG. The sensor 56 is annular and has an inner ring 102 , an outer ring 104 , a plurality of beams 106 and a plurality of strain gauges 108 .

The inner ring 102 has a through hole at its center. The outer ring 104 is spaced radially outward of the inner ring 102 . The beam portions 106 extend in the radial direction between the inner ring 102 and the outer ring 104 and are arranged side by side at substantially equal intervals in the circumferential direction. A gap 110 is defined between two beams 106 that are circumferentially adjacent to each other.

A strain gauge 108 is provided on each beam portion 106 and converts the strain generated in the beam portion 106 into an electrical signal. In this embodiment, the inner ring 102 is fixed to the main body portion 94 of the output shaft 90 by fasteners (not shown) such as bolts, while the outer ring 104 is fixed to the proximal end portion 24a of the tip arm 24 by bolts or the like. It is secured by fasteners (not shown). In this state, the inner ring 102 contacts the output shaft 90 (specifically, the body portion 94 ), while the outer ring 104 and the beam portion 106 are separated from the output shaft 90 .

When the stator 64 of the electric motor 52 rotates the rotor 66 in the circumferential direction at the speed V1, the rotor shaft 76 also rotates the internal gear 86 and the external gear 88 of the reduction gear 54, respectively. The internal gear 86 and the external gear 88 are interposed between the rotor shaft 76 and the output shaft 90, and after reducing the rotation of the rotor shaft 76 from the speed V1 to the speed V2 (<<V1), output It is transmitted to the output shaft 90 via the pin 95 .

Thus, the speed reducer 54 slows down the rotation of the rotor 66 . For example, the speed V2 is 1% or less of the speed V1. The sensor 56 rotates circumferentially together with the output shaft 90 at a speed V2, and as a result, the tip arm 24 fixed to the outer ring 104 of the sensor 56 also rotates circumferentially at a speed V2. Thus, distal arm 24 will rotate relative to proximal arm 22 .

Thus, the power generated by the stator 64 rotates the rotor 66 (rotor shaft 76, rotor core 78), the rotary slit 68a, the brake disc 70a, the internal gear 86, the external gear 88, the output shaft 90, and the sensor 56, respectively. be. Therefore, in this embodiment, the rotor 66, the rotary slit 68a, the brake disc 70a, the internal gear 86, the external gear 88, the output shaft 90, and the sensor 56 constitute the rotary portion 134 of the rotary shaft structure 50. Each of rotor 66 , rotary slit 68 a , brake disc 70 a , internal gear 86 , external gear 88 , output shaft 90 , and sensor 56 can then be defined as rotating elements of rotating portion 134 .

On the other hand, housing 62 and stator 64 (stator core 72, coil 74) of electric motor 52, light emitting portion 68b and light receiving portion 68c of encoder 68, end plate 70b and brake core 70d of brake mechanism 70, reduction gear 54 The housing 84 is fixed relative to the proximal arm 22 .

Therefore, in this embodiment, the housings 62 and 84, the light emitting portion 68b and the light receiving portion 68c, the end plate 70b and the brake core 70d, and the stator 64 constitute the fixed portion 136 of the rotating shaft structure 50. Each of housings 62 and 84 , light emitting portion 68 b and light receiving portion 68 c , end plate 70 b and brake core 70 d , and stator 64 can be defined as fixed elements of fixed portion 136 .

The rotating portion 134 is provided on the fixed portion 136 so as to be rotatable in the circumferential direction. , through-holes 138 are defined axially through the rotating portion 134 and the fixed portion 136 .

In this embodiment, the through-hole 138 is arranged substantially coaxial with the fourth rotation axis J4 and opens to the outside at the axial rear end 76b of the rotor shaft 76 (or the axial rear end of the end wall 62c). It has a first open end 138a and a second open end 138b that opens outward at the axial front end of the sensor 56 (specifically, the inner ring 102). The filamentary body 26 is wired so as to pass through the through hole 138 .

The restraining member 58 holds the filamentary body 26 along with the rotating section 134 so that the filamentous body 26 rotates along with the rotating section 134 in the axial section A from the first open end 138a to the second open end 138b. constrained to Specifically, the restraining member 58 has a restraining tube 140 , a first securing member 142 and a second securing member 144 .

The restraint pipe 140 is arranged inside the through-hole 138 so as to surround the filamentary body 26 from the outside in the radial direction over the section A. More specifically, the restraint tube 140 is made of, for example, metal, resin, rubber, or a combination thereof, and includes a tubular portion 146 that surrounds the filamentous body 26 in section A, and the tubular portion 146 and a flange portion 148 extending radially outwardly from.

In the present embodiment, the tubular portion 146 is cylindrical, and the axial rear end portion 146a thereof is located further axially than the axial rear end 76b of the rotor shaft 76 and the axial rear end face of the end wall 62c. While protruding rearward, the axial front end 146 b extends within the through hole 138 so as to protrude axially forward beyond the axial front end surface of the sensor 56 .

The flange portion 148 is arranged at a position closer to the axial front end portion 146b than the axial rear end portion 146a of the tubular portion 146, and extends in the circumferential direction over the entire circumference of the outer peripheral surface 146c of the tubular portion 146. are doing. In this embodiment, the flange portion 148 is sandwiched between the inner ring 102 of the sensor 56 and the inner flange 98 of the output shaft 90, so that the restraint tube 140 is aligned with the rotor relative to the fourth rotational axis J4. It is arranged substantially coaxially with the shaft 76 and held inside the through hole 138 so that the cylindrical portion 146 extends parallel to the axial direction.

In this way, the constraining pipe 140 is fixed to the sensor 56 and the output shaft 90 of the rotating portion 134 by clamping the flange portion 148 between the inner ring 102 and the inner flange 98 , and the sensor 56 and the output shaft 90 are connected to each other. They rotate together at a speed of V2. At this time, the outer peripheral surface 146c of the cylindrical portion 146 becomes substantially parallel to the inner peripheral surface 76c of the rotor shaft 76 and is spaced radially inward from the inner peripheral surface 76c.

Therefore, the tubular portion 146 rotating at the speed V2 together with the sensor 56 and the output shaft 90 does not interfere with the rotor shaft 76 rotating at the speed V1. Therefore, it is possible to prevent the cylindrical portion 146 from being damaged due to interference with the rotor shaft 76 rotating at a higher speed.

An elastic member (such as an O-ring) may be interposed between the flange portion 148 and the inner ring 102 . In this case, the flange portion 148 and the inner ring 102 may be axially separated from each other. With this configuration, the force applied from the flange portion 148 to the inner ring 102 can be reduced, so the force detection accuracy of the sensor 56 can be improved.

Also, the restraint pipe 140 may be fixed to the inner flange 98 (or the inner ring 102) by fastening the flange portion 148 to the inner flange 98 (or the inner ring 102) with fasteners such as bolts. In this case, the flange portion 148 may be arranged so as to be separated from the inner ring 102 .

The first fixing member 142 is provided at an axial rear end portion 146a of the cylindrical portion 146 so as to be adjacent to the first open end 138a, and allows the linear body 26 to rotate relative to the axial rear end portion 146a. Impossibly fixed. In this embodiment, the first fixing member 142 is slightly axially rearward from the first open end 138a (or the axial rear end 76b of the rotor shaft 76 and the axial rear end face of the end wall 62c). are spaced apart.

The first fixing member 142 is, for example, heat-shrinkable resin (so-called heat-shrinkable tube), shape-memory resin, or restraint band (for example, nylon band). By tightening 146a from the outer peripheral side, the filamentous body 26 is fixed to the axial rear end portion 146a so as not to rotate relative to it.

On the other hand, the second fixing member 144 is provided at the axial front end portion 146b of the cylindrical portion 146 so as to be adjacent to the second open end 138b, and prevents the linear body 26 from rotating relative to the axial direction front end portion 146b. fixed to In this embodiment, the second fixing member 144 is arranged slightly spaced axially forward from the second open end 138b (or the axial front end face of the sensor 56).

Like the first fixing member 142, the second fixing member 144 is made of a heat-shrinkable resin, a shape-memory resin, a restraint band, or the like, and tightens the filamentous body 26 and the axial front end portion 146b from the outer peripheral side. Thus, the filamentary body 26 is fixed to the axial front end portion 146b so as not to rotate relative to each other. An adhesive may be applied to the inner peripheral surface of at least one of the first fixing member 142 and the second fixing member 144 .

Further, the cylindrical portion 146 may be arranged with its axial rear end portion 146 a spaced radially inward of the rotor shaft 76 (in other words, housed inside the through hole 138 ). In this case, the axial rear end portion 146a of the cylindrical portion 146 does not protrude axially rearward beyond the axial rear end 76b of the rotor shaft 76 and the axial rear end surface of the end wall 62c.

Similarly, the tubular portion 146 may be spaced radially inward of the inner ring 102 of the sensor 56 (in other words, housed inside the through hole 138) at its axial front end portion 146b. In this case, the axial front end portion 146 b of the cylindrical portion 146 does not protrude axially forward beyond the axial front end surface of the sensor 56 .

In this manner, when the axial rear end portion 146a and the axial front end portion 146b of the tubular portion 146 are housed inside the through hole 138, at least the first fixing member 142 and the second fixing member 144 are One may be housed inside the through hole 138 so as not to contact the rotor shaft 76 and the inner ring 102 of the sensor 56 .

The filamentous body 26 is fixed to the restraint tube 140 by the first fixing member 142 and the second fixing member 144, so that it is constrained inside the inner peripheral surface 146d of the cylindrical portion 146 so as not to rotate relative to the inner peripheral surface 146d. It is wired so as to extend axially inside the inner peripheral surface 146d. The filamentary body 26 is fixed to the sensor 56 and the output shaft 90 of the rotating portion 134 via the restraint tube 140 , the first fixing member 142 and the second fixing member 144 .

With such a restraint member 58 (constraint pipe 140, first fixing member 142, and second fixing member 144), the filamentous body 26 is fixed to the sensor 56 and the output shaft 90 in section A when the sensor 56 and the output shaft 90 rotate. The sensor 56 and the output shaft 90 are constrained to rotate with 56 and the output shaft 90 at a velocity V2.

As described above, in the present embodiment, the rotating shaft structure 50 includes the hollow fixed portion 136 and the hollow rotating portion 134 rotatably provided in the fixed portion 136 and defining the through hole 138 together with the fixed portion 136 . , and a restraining member 58 that restrains the linear body 26 to the rotating part 134 so that the linear body 26 rotates together with the rotating part 134 (specifically, the sensor 56 and the output shaft 90) in the section A.

According to this configuration, even if the rotating part 134 rotates, the filamentous body 26 will not be twisted in the section A inside the through hole 138 . Therefore, since the filamentous bodies 26 can be densely wired inside the through-hole 138, a sufficient number of filamentous bodies 26 can be wired inside the through-hole 138 even if the rotation shaft structure 50 is made compact, for example. can do.

Further, in this embodiment, the restraining member 58 is arranged inside the through hole 138 so as to surround the filament 26 in the section A, and rotates together with the rotating portion 134 (the sensor 56 and the output shaft 90). A cylindrical restraint tube 140 is fixed to the rotating portion 134, and the filamentous body 26 is restrained inside the restraint tube 140 so as not to rotate relative to each other. According to this configuration, the filamentous body 26 can be effectively restrained by the rotating portion 134 over the section A through the restraint pipe 140, so that the filamentous body 26 is Twisting can be effectively prevented.

Further, in this embodiment, the restraint pipe 140 includes a tubular portion 146 surrounding the filamentous body 26 in the section A, a tubular portion 146 extending radially outward from the tubular portion 146, and a rotating portion 134 (sensor 56, and a flange portion 148 fixed to the output shaft 90). According to this configuration, the filamentous body 26 can be constrained to the cylindrical portion 146 over the section A, while the constraining pipe 140 can be easily fixed to the rotating portion 134 via the flange portion 148 .

Also, in this embodiment, the restraint member 58 is provided adjacent to the first open end 138a, and fixes the filamentous body 26 to the rotating portion 134 (sensor 56, output shaft 90). It further has a fixing member 142 and a second fixing member 144 provided adjacent to the second open end 138 b to fix the filament 26 to the rotating portion 134 .

According to this configuration, the filamentous body 26 can be constrained to the rotating portion 134 at a position adjacent to the first open end 138a and a position adjacent to the second open end 138b. It is possible to more effectively prevent the filamentous body 26 from being twisted in the section A when 134 rotates.

At least one of the first fixing member 142 and the second fixing member 144 may be omitted from the restraining member 58 . In this case, the restraining member 58 may have a restraining tube 140 and an adhesive applied to the inner peripheral surface 146 d of the cylindrical portion 146 of the restraining tube 140 . In this case as well, the filamentous body 26 can be restrained inside the tubular portion 146 .

Alternatively, instead of applying an adhesive to the inner peripheral surface 146d, a filamentous body 26 may be provided inside the restraint tube 140 so that the filamentous body 26 is in close contact with the inner peripheral surface 146d of the tubular portion 146 with pressure. 26 may be densely wired. In this case, the filamentous body 26 is constrained inside the constraining tube 140 by the frictional force between it and the inner peripheral surface 146d. Thus, the restraining member 58 may have any structure for immovably restraining the filament 26 to the tubular portion 146 .

Next, a machine 30 according to another embodiment will be described with reference to FIGS. 4 and 5. FIG. The machine 30 differs from the machine 10 described above in that it comprises a first type filament 26A, a second type filament 26B, a fixed structure 32, and a rotating shaft structure 150. FIG. The fixing structure 32 is provided on the base end arm 22 (specifically, the base portion 22a or the cylindrical portion 22b) and is spaced apart from the through hole 138 on the rear side in the axial direction.

More specifically, the fixing structure 32 has a body portion 32a fixed to the base end arm 22 and a clamp portion 32b fixed to the body portion 32a. The second type filamentous body 26B is inserted and fixed inside the clamp portion 32b, thereby being fixed to the base end arm 22 and the fixing portion 136. As shown in FIG.

The rotating shaft structure 150 differs from the rotating shaft structure 50 described above in the restraining member 152 . Specifically, the restraint member 152 further includes a circuit relay portion 154 in addition to the restraint tube 140 , the first fixing member 142 , and the second fixing member 144 described above. In this embodiment, the circuit relay portion 154 is integrally incorporated into the first fixing member 142 and fixed to the sensor 56 and the output shaft 90 of the rotating portion 134 via the restraint pipe 140 .

As an example, the circuit relaying part 154 is a connector that electrically connects the first type filament 26A and the second type filament 26B. As another example, the circuit relay part 154 is a circuit board (printed circuit board: PCB, etc.), and the first type filament 26A and the second type filament 26B are electrically connected by soldering or the like. may As still another example, the circuit relay portion 154 may be solder itself that connects the first type filament 26A and the second type filament 26B instead of the circuit board. As still another example, the circuit relay portion 154 may have a crimp terminal that connects the first type filament 26A and the second type filament 26B.

The first type filament 26A is, for example, a non-movable filament, extends axially forward from the circuit relay portion 154, and passes through the section A. On the other hand, the second type filament 26B is, for example, a movable filament and has higher resistance to deformation (specifically, twisting or bending) than the first type filament 26A. have The second type filament 26B is arranged on the rear side of the through hole 138 in the axial direction, and the through hole 138 (specifically, the circuit relay portion 154) and the fixing structure 32 (specifically, the clamp portion) 32b), and is connected to the first type filament 26A via the circuit relay portion 154.

In the present embodiment, the circuit relay portion 154 is wholly housed inside the first fixing member 142, thereby connecting the front end 26B of the second type filament 26B to the circuit relay portion 154. ' is surrounded and fixed by the first fixing member 142 . At least a portion of the filamentary body 26A or 26B may be formed of a circuit board.

When the sensor 56 and the output shaft 90 are rotated, the circuit relay portion 154 rotates in the circumferential direction with respect to the clamp portion 32b of the fixing structure 32, and as a result, the second type filament 26B is twisted in the section B. You will be tormented. Here, as described above, the second type filament 26B has higher resistance to deformation (torsion or bending) load than the first type filament 26A. It is possible to prevent disconnection even if the wire is twisted.

Further, in this embodiment, as described above, the front end 26B' of the second type filament 26B is surrounded and fixed by the first fixing member 142. According to this configuration, even if the second type filament 26B is twisted in the section B due to the rotation of the sensor 56 and the output shaft 90, the twist of the second type filament 26B is can be prevented from being transmitted to the circuit relay unit 154 through the

Therefore, it is possible to prevent the circuit relay portion 154 from disconnecting the first type filament 26A and the second type filament 26B. An annular clamping member is incorporated in the first fixing member 142, and the front end 26B' of the second type filamentous body 26B is clamped by the clamping member so that the front end 26B' is clamped to the first fixing member 142. It may be immovably fixed inside one fixing member 142 .

Note that the axial distance L _B of the section B may be set to be greater than or equal to the axial distance L _A of the section A (that is, L _B ≧ _LA ). By setting the distance _LB in this way, the shearing force applied to the second type filament 26B when it is twisted in the section B is reduced, thereby effectively preventing disconnection. can be prevented.

As described above, in the present embodiment, the machine 30 further includes the fixing structure 32 that fixes the filament 26B to the fixing portion 136 outside the through hole 138, and the rotating portion 134 (sensor 56 and output shaft 90) is rotated, filament 26B is twisted in section B. According to this configuration, wiring can be effectively performed inside the base end arm 22 by fixing the filamentous body 26B to the base end arm 22 . Note that the fixing structure 32 may be fixed to the fixing portion 136 of the rotating shaft structure 150 via a fixture.

Further, in the present embodiment, the filament 26 includes the first type filament 26A extending in the section A and the first type filament 26A extending in the section B and connected to the first type filament 26A. and a second type filament 26B having higher resistance to deformation (torsion or bending) load than the first type filament 26A. According to this configuration, even if the second type filament 26B is twisted in the section B, disconnection can be effectively prevented.

In this embodiment, the restraining member 152 is fixed to the rotating part 134 (the sensor 56 and the output shaft 90), and electrically connects the first type filament 26A and the second type filament 26B. It has a circuit relay unit 154 that allows According to this configuration, the first type filament 26A and the second type filament 26B can be easily connected and removed. In this embodiment, in both sections A and B, as the filamentous body 26, the second type filamentous body 26B (or the first type filamentous body 26A) may be used. In this case, the circuit relay section 154 can be omitted.

Next, a method of assembling the rotating shaft structure 150 and the filaments 26A and 26B will be described. First, the manufacturer inserts the first type filament 26A into the restraint tube 140, the first fixing member 142, and the second fixing member 144, and connects one end thereof to the circuit relay portion 154. Thus, a filamentary body unit 156 as an assembly of the first filamentary body 26A and the restraining member 152 is manufactured.

The manufacturer then manufactures an assembly of the electric motor 52 and the reduction gear 54 . Next, the manufacturer fixes the sensor 56 to the output shaft 90 with the flange portion 148 of the restraint pipe 140 interposed between the sensor 56 and the output shaft 90 . Thus, the flange portion 148 is sandwiched between the sensor 56 and the output shaft 90, and the filamentary body unit 156 is fixed to the rotating portion 134 (specifically, the sensor 56 and the output shaft 90).

Next, the manufacturer inserts and fixes the second type filament 26B into the clamp portion 32b of the fixing structure 32, and connects one end thereof to the circuit relay portion 154. Thus, the filaments 26A and 26B are wired to pass through the sections A and B, thereby manufacturing an assembly of the rotating shaft structure 150 and the filaments 26A and 26B.

It should be noted that the above-described restraint pipe 140 may be made of a combination of resin and metal (for example, iron). For example, the tubular portion 146 may be made of resin while the flange portion 148 is made of metal. In this case, the axial rear end surface of the flange portion 148 may be formed by cutting in order to improve flatness. According to this configuration, the axial rear end face of the flange portion 148 and the axial front end face of the inner flange 98 facing the rear end face can be brought into close contact with each other to increase the frictional force therebetween. Note that the restricting tube 140 may be composed only of metal. Also, the first type filament 26A may be composed of the second type filament 26B. In this case, in sections A and B, the second type filament 26B is wired.

Next, a rotation shaft structure 160 according to another embodiment will be described with reference to FIGS. 6 and 7. FIG. The rotating shaft structure 160 differs from the rotating shaft structure 150 described above in the restraining member 162 . The restraining member 162 is made of, for example, metal or resin, and is arranged so that the linear body 26 rotates together with the sensor 56 and the output shaft 90 of the rotating portion 134 in the section A in the same manner as the restraining member 58 described above. Constrain body 26 to sensor 56 and output shaft 90 .

More specifically, the restraining member 162 has a mounting portion 164 , a first arm portion 166 , a second arm portion 168 , a first fixing member 170 and a second fixing member 172 . The mounting portion 164 is a hollow flat plate member having a substantially rectangular outer shape as shown in FIG. It is fixed to the shaft 90 . In this embodiment, each fastener 174 passes through the gap 110 of the sensor 56 and its tip is fastened to a fastening hole 94c formed in the body portion 94 of the output shaft 90. As shown in FIG.

The first arm portion 166 extends radially inward from the inner surface of the portion forming one apex angle of the mounting portion 164 and extends radially to a position adjacent to the second open end 138b. The second arm portion 168 extends axially rearward from the radially inner end of the first arm portion 166 and extends axially to a position adjacent the first open end 138a.

The first fixing member 170 is, for example, an annular member, and is provided integrally with the axial rear end portion of the second arm portion 168 so as to be adjacent to the first open end 138a. The first fixing member 170 fixes the filamentous body 26 to the sensor 56 and the output shaft 90 of the rotating portion 134 by inserting and fixing the filamentous body 26 therein. In this embodiment, the first fixing member 170 is arranged inside the through hole 138 .

It should be noted that the first fixing member 170 may have a pair of claws that can be opened and closed, and the linear body 26 may be clamped by sandwiching the linear body 26 with the pair of claws. Alternatively, the first fixing member 170 wraps the filamentary body 26 with a protective elastic body, and binds the outer circumference of the elastic body to the second arm portion 168 with a restraining band (nylon band or the like). It may be something to do.

Alternatively, the first fixing member 170 may be heat-shrinkable resin or the like for binding the filamentous body 26 to the second arm portion 168 like the first fixing member 142 described above. A first fixing member 142 may be applied in addition to the fixing member 170 to bind the filament 26 to the first fixing member 170 .

On the other hand, the second fixing member 172 has a configuration similar to that of the first fixing member 170, and is provided integrally with the axial front end portion of the second arm portion 168 so as to be adjacent to the second open end 138b. It is The second fixing member 172 fixes the filamentous body 26 to the sensor 56 and the output shaft 90 of the rotating portion 134 by inserting and fixing the filamentous body 26 therein. In this embodiment, the second fixing member 172 is arranged inside the inner ring 102 of the sensor 56 .

The second fixing member 172 may be heat-shrinkable resin or the like for binding the filamentous body 26 to the second arm portion 168 like the second fixing member 144 described above. A second fixing member 144 may be applied in addition to the fixing member 172 to bind the filament 26 to the second fixing member 172 .

In this embodiment, the restraining member 162 is spaced apart from the sensor 56 and does not contact the sensor 56 . Also, as mentioned above, the fastener 174 is also out of contact with the sensor 56 by passing through the gap 110 of the sensor 56 . Thus, by completely spatially separating restraining member 162 and fastener 174 from sensor 56 , the force exerted by restraining member 162 and fastener 174 on sensor 56 can be substantially zero. Thereby, the force detection accuracy of the sensor 56 can be improved.

The restraining member 162 restrains the filamentous body 26 by the first fixing member 170 and the second fixing member 172 so that they cannot rotate relative to each other. As a result, when the sensor 56 and the output shaft 90 rotate, the linear body 26 rotates together with the sensor 56 and the output shaft 90 at the speed V2 in the section A. be restrained.

As described above, in the present embodiment, the restraint member 162 is provided adjacent to the first open end 138a, and fixes the filamentous body 26 to the rotating portion 134 (sensor 56, output shaft 90). It has a first fixing member 170 and a second fixing member 172 that is provided adjacent to the second open end 138 b and fixes the filament 26 to the rotating portion 134 .

According to this configuration, the filamentous body 26 can be constrained to the rotating portion 134 at a position adjacent to the first open end 138a and a position adjacent to the second open end 138b. It is possible to more effectively prevent the filamentous body 26 from being twisted in the section A when 134 rotates.

Note that the features of the rotating shaft structures 50, 150 and 160 described above can be combined. For example, after omitting the flange portion 148 from the restraining tube 140 of the rotating shaft structure 50, it is applied to the rotating shaft structure 160, the linear body 26 is inserted inside the restraining tube 140, and the restraining tube 140 is used as a restraining member. It may be clamped to first fixation member 170 and second fixation member 172 at 162 . Alternatively, the circuit relay portion 154 of the rotary shaft structure 150 is provided integrally with the first fixing member 170 of the rotary shaft structure 160, and the section A is wired with the first type filament 26A, while the section B is wired with the second type may be wired to connect both at the circuit relay portion 154 .

It should be noted that the machine 10 or 30 described above (or the machine 30' described later) may further include an electronic component such as a substrate disposed within the through-hole 138. Also, the speed reducer 54 can be omitted from the rotary shaft structure 50, 150 or 160 described above (so-called direct drive system).

Also, in the above-described embodiment, the case where the electric motor 52, the speed reducer 54, and the sensor 56 are arranged substantially coaxially with the fourth rotation axis J4 as a reference and arranged side by side in the axial direction has been described. However, not limited to this, for example, the electric motor 52 may be arranged at a position offset from the rotation axis J4.

In this case, the electric motor 52 includes a stator 64 arranged at a position offset from the rotation axis J4, an output shaft rotatably driven by the stator 64, a rotor shaft 76 arranged coaxially with the rotation axis J4, and the A rotation transmission mechanism (for example, a pulley mechanism) that transmits the rotation of the output shaft to the rotor shaft 76 may be provided. Also, the electric motor 52 may be arranged radially outside the speed reducer 54 and the sensor 56 .

Further, the sensor 56 is not limited to having the inner ring 102, the outer ring 104, and the beam portion 106, and may have, for example, a ring member such as the inner ring 102 provided with the strain gauge 108. Also, in the rotary shaft structure 50, 150 or 160, instead of the reducer 54 or the sensor 56, any annular member may be applied as the rotary element.

Also, in the above-described embodiment, the case where the restraint pipe 140 is arranged coaxially with the rotor shaft 76 with the axis J4 as a reference has been described. However, the restriction tube 140 is not limited to this and may be arranged at a position where its central axis is radially offset from the fourth rotation axis J4. In this case, the tubular portion 146 is held so as to extend parallel to the fourth rotation axis J4, while the central axis of the tubular portion 146 is radially displaced from the fourth rotation axis J4 by a predetermined distance. It will be arranged with a shift.

Further, in the above-described embodiment, the case where the housing 62 is fixed to the cylindrical portion 22b of the proximal end arm 22 and the sensor 56 (outer ring 104) is fixed to the proximal end portion 24a of the distal end arm 24 has been described. . However, without being limited to this, the housing 62 may be fixed to the proximal end portion 24 a of the distal arm 24 and the sensor 56 (for example, the outer ring 104 ) may be fixed to the cylindrical portion 22 b of the proximal arm 22 . Such a configuration is shown in FIG.

In the machine 30' shown in FIG. 8, the rotating shaft structure 150 shown in FIGS. Outer ring 104 is fixed to cylindrical portion 22b of proximal arm 22, while housing 62 of electric motor 52 is fixed to proximal portion 24a of distal arm 24. As shown in FIG.

Further, the fixing structure 32 is provided inside the distal arm 24 and is spaced apart from the through hole 138 (specifically, the open end 138a) in the direction toward the distal end portion 24b of the distal arm 24. The second type filamentous body 26B extends from the rotating shaft structure 150 toward the distal end portion 24b of the distal end arm 24, and is inserted and fixed inside the clamp portion 32b (FIG. 5) of the fixing structure 32. As shown in FIG. Thereby, the second type filament 26B is fixed to the tip arm 24 and the fixing portion 136 .

In this embodiment, when the stator 64 of the electric motor 52 generates power to rotate the rotor 66, the sensor 56 and the output shaft 90 of the rotating portion 134 are fixed to the cylindrical portion 22b of the proximal arm 22. , the fixed portion 136 rotates relative to the rotating portion 134 about the fourth rotational axis J4, thereby driving the distal arm 24 to rotate relative to the proximal arm 22 about the fourth rotational axis J4. will be

Also in this case, the rotating part 134 can be considered to rotate relative to the fixed part 136 . That is, in this paper, the "rotating part" can be defined as rotating relative to the "fixed part". As the fixing portion 136 and the tip arm 24 rotate, the second type filament 26B is twisted in the section B (see FIG. 5).

According to this embodiment, it is possible to provide the section B on the tip arm 24 side, and as a result, the section B can be set long. In addition, since the rotating shaft structure 150 can be arranged on the proximal side of the distal arm 24, the inertial force of the distal arm 24 during rotation can be reduced.

It should be noted that in the above-described embodiments, pivot structures 50, 150, and 160 are positioned between proximal arm 22 and distal arm 24 to rotate distal arm 24 relative to proximal arm 22 along a fourth axis of rotation. The case of rotationally driving around J4 has been described. However, the axis of rotation structure 50, 150 or 160 may be provided on the axis of rotation J1, J2, J3, J5 or J6 of any joint of the machine 10.

For example, the pivot structure 50, 150 or 160 may be positioned between the robot base 12 and the proximal end 16a of the upper arm 16 to position the upper arm 16 relative to the robot base 12 along the second axis of rotation J2. or positioned between the tip 16b of the upper arm 16 and the base 22a of the forearm 18 to rotate the forearm 18 relative to the upper arm 16 along a third axis of rotation. It may be rotationally driven around J3.

In addition, the machine 10 or 30 is not limited to a vertical multi-joint robot, but any type of robot such as a horizontal multi-joint robot or a parallel link robot, or a rotary positioner that rotatably supports a workpiece. It can be any type of machine with movable components that are driven to rotate about it. As described above, the present disclosure has been described through the embodiments, but the above-described embodiments do not limit the invention according to the scope of claims.

10, 30, 30' machine 26, 26A, 26B filamentary body 32 fixed structure 50, 150, 160 rotating shaft structure 58, 152, 162 restraining member 134 rotating part 136 fixed part 138 through hole 138a, 138b opening end 140 restraining pipe 146 cylindrical portion 148 flange portion 142, 144, 170, 172 fixing member

Claims (8)

a hollow fixed part;
A hollow rotating part provided in the fixed part so as to be rotatable around a rotation axis, wherein the rotating part and the fixed part are penetrated in the direction of the rotation axis, and a filament passes through the inside. a rotatable portion defining, with the fixed portion, a through-hole for
a restraining member that restrains the linear body to the rotating part so that the linear body rotates together with the rotating part in a section from one open end of the through hole to the other open end; Rotating shaft structure. The restraint member has a tubular restraint tube disposed inside the through hole so as to surround the filamentary body in the section and fixed to the rotating part so as to rotate together with the rotating part. ,
2. The rotary shaft structure according to claim 1, wherein said filamentary body is restrained inside said restraint tube so as not to rotate relative to each other. The constraining tube is
a cylindrical portion surrounding the filamentary body in the section;
3. The rotating shaft structure according to claim 2, further comprising a flange portion extending radially outward from said cylindrical portion and fixed to said rotating portion. The restraining member is
a first fixing member provided adjacent to the one open end for fixing the filamentous body to the rotating portion;
and a second fixing member that is provided adjacent to the other open end and fixes the filamentous body to the rotating portion, according to any one of claims 1 to 3. Rotating shaft structure. A rotating shaft structure according to any one of claims 1 to 4;
A machine comprising the striatum. further comprising a fixing structure for fixing the filamentary body to the fixing portion outside the through hole,
6. The machine of claim 5, wherein as the rotating part is rotated, the filament is twisted in a second section between the throughbore and the stationary structure. The striatum is
a first type striatum extending in the section;
a second type of filament extending in the second section and connected to the first type of filament and having a higher resistance to deformation than the first type of filament. 7. A machine according to claim 6. The machine according to claim 7, wherein the restraining member has a circuit relay portion that is fixed to the rotating portion and electrically connects the first type filamentous body and the second type filamentous body.

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