Collaborative robots

Abstract

The present invention provides a collaborative robot that allows for easy attachment and detachment of the fifth-axis motor and torque converter from the upper arm. [Solution] The output shaft 512 of the fifth-axis motor 51, which rotates the support arm 16 of the collaborative robot 1 around the fifth axis A5, is positioned along the fourth axis A4. Inside the upper arm 15 of the collaborative robot 1, the fifth-axis motor 51 and a torque converter 53 that converts the torque of the output shaft 512 into torque around the fifth axis A5 are housed. The upper arm 15 is a cylindrical housing and has an arm body 151 with an opening 2 for mounting the fifth-axis motor 51 and the torque converter 53, and a cover 152 that covers the opening 2 and is attached to the arm body 151. When viewed from a direction along the fifth axis A5, the fifth-axis motor 51 and the torque converter 53 are housed in the internal region within the opening edge 20 of the opening 2.

Description

Technical Field

[0001] The present invention relates to a collaborative robot.

Background Art

[0002] As a technology of this kind, for example, Patent Document 1 discloses an articulated robot including an upper arm connected to a lower arm and a support arm pivotally attached to the tip of the upper arm. In this kind of robot, usually, a motor (motor for the fifth axis) for rotating the support arm is often housed in the upper arm. Here, when the output shaft of the motor for the fifth axis is arranged along the fourth axis which is the axis of the upper arm, the upper arm can be made slimmer compared with the case where the output shaft of the motor for the fifth axis is arranged along the fifth axis.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the articulated robot described in Patent Document 1 is a collaborative robot. When the output shaft of the motor for the fifth axis is arranged along the fourth axis, a torque converter for converting the torque of the output shaft of the motor for the fifth axis into the torque around the fifth axis is connected to the output shaft, and the attachment and detachment of the motor for the fifth axis and the torque converter become complicated.

[0005] The present invention has been made in view of such points, and an object thereof is to provide a collaborative robot that enables easy attachment and detachment of the motor for the fifth axis and the torque converter to and from the upper arm.

Means for Solving the Problems

[0006] In view of the above problems, the collaborative robot according to the present invention comprises: a turntable pivotally attached to a base so as to be rotatable around a first axis; a lower arm pivotally attached to the turntable so as to be rotatable around a second axis; a shoulder pivotally attached to the lower arm so as to be rotatable around a third axis parallel to the second axis; an upper arm pivotally attached to the shoulder so as to be rotatable around a fourth axis along the longitudinal direction; a support arm pivotally attached at the tip of the upper arm so as to be rotatable around a fifth axis perpendicular to the fourth axis; and a tip member pivotally attached to the support arm so as to be rotatable around a sixth axis along the longitudinal direction, With the output shaft of the fifth-axis motor that rotates the support arm around the fifth axis positioned along the fourth axis, the upper arm houses the fifth-axis motor and a torque converter that converts the torque of the output shaft into torque around the fifth axis. The upper arm is a cylindrical housing and has an arm body with an opening for mounting the fifth-axis motor and the torque converter, and a cover that covers the opening and is attached to the arm body. When viewed from a direction along the fifth axis, the fifth-axis motor and the torque converter are housed in the internal region within the opening edge of the opening.

[0007] According to the present invention, when viewed from a direction along the fifth axis, the fifth-axis motor and torque converter are housed in the internal region within the opening edge of the opening. This makes it easy to attach the fifth-axis motor and torque converter to and detach them from the upper arm via the opening in the upper arm, along the fifth axis.

[0008] In a more preferred embodiment, the motor for the fifth axis and the torque converter have protruding portions that extend from the opening edge of the opening.

[0009] According to this embodiment, the motor for the fifth axis and the torque converter can be more easily removed from the opening by gripping the protruding portion or its vicinity.

[0010] In a more preferred embodiment, the motor for the fifth axis has a motor body, and when viewed from a direction along the fifth axis, a gap is formed between a pair of sides of the motor body along the direction of the fourth axis and the opposing edge of the opening edge that faces each of the sides, and the gap is formed to widen from the shoulder end of the side along the fourth axis toward the torque converter side.

[0011] In this configuration, the opposing edge of the opening bulges outward, allowing an operator to easily remove the fifth-axis motor from the opening by reaching their hand through the gap between the side of the fifth-axis motor and the opposing edge.

[0012] In a more preferred embodiment, the torque converter is fixed to the arm body, and the fifth-axis motor is suspended from the torque converter via a bracket that houses the output shaft of the fifth-axis motor.

[0013] In this embodiment, in addition to the gap described above, a gap is also formed below the fifth-axis motor, making it easier to remove the fifth-axis motor from the opening together with the bracket. Furthermore, these gaps improve heat dissipation associated with the rotation of the fifth-axis motor.

[0014] In a more preferred embodiment, the protruding portion of the torque converter is attached to the bracket via a fastener, and the protruding portion of the torque converter and the bracket have insertion holes formed in a direction along the fourth axis into which the fastener is inserted.

[0015] According to this embodiment, when the collaborative robot is in operation, the fifth-axis motor and torque converter can be integrally fixed via a fixing device. Furthermore, when performing maintenance on the fifth-axis motor and torque converter, the fixing device can be removed from the protruding portion of the torque converter in the direction along the fourth axis, and then the fifth-axis motor can be easily removed from the opening. After that, the torque converter can also be easily removed from the opening.

[0016] In a more preferred embodiment, in a cross-section perpendicular to the fourth axis, the thickness of the opening edge of the opening is greater than the thickness of the other parts.

[0017] According to this embodiment, the bending strength of the upper arm (arm body), including the opening edge, can be ensured even when the cover is removed.

[0018] In a more preferred embodiment, the shoulder houses a fourth-axis motor that rotates the upper arm around the fourth axis, and a cavity is formed inside the upper arm on the shoulder side of the fifth-axis motor to house wiring connected to the fifth-axis motor.

[0019] In this configuration, since the fourth-axis motor is not located in the cavity, the wiring housed in the cavity will not get caught on the fourth-axis motor. Therefore, excess wiring can be housed in the cavity, the fifth-axis motor can be removed from the opening, and the housed excess wiring can be smoothly pulled out from the opening. [Effects of the Invention]

[0020] According to the present invention, the motor and torque converter for the fifth axis can be easily attached to and removed from the upper arm. [Brief explanation of the drawing]

[0021] [Figure 1] This is a perspective view of the collaborative robot according to this embodiment. [Figure 2] The figure is a view of the upper arm of the collaborative robot according to the present embodiment as seen from the direction along the fifth axis with the cover removed. [Figure 3] (A) is a view of the collaborative robot shown in FIG. 2 as seen from the plane including the fourth axis and the fifth axis. (B) is a cross-sectional view showing a part of the internal configuration of the collaborative robot shown in (A). [Figure 4] The perspective view is for explaining a method of removing the fifth-axis motor from the arm body of the collaborative robot according to the present embodiment. [Figure 5] The cross-sectional view shows a cross-section of the arm body of the collaborative robot according to the present embodiment perpendicular to the fourth axis. (A) is a cross-sectional view including the opening edge of the opening, and (B) is a cross-sectional view not including the opening edge of the opening.

Embodiments for Carrying Out the Invention

[0022] 〔Embodiment〕 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings of FIGS. 1 to 5(B). Note that the embodiments shown below are one aspect of the present invention and do not limit the technical scope of the present invention.

[0023] <Device Configuration> FIG. 1 is a perspective view of a collaborative robot 1 according to the present embodiment. As shown in FIG. 1, the collaborative robot 1 is an articulated robot and is used by attaching an end effector (not shown) such as a welding device (torch) to the tip member 17 of the collaborative robot 1.

[0024] The collaborative robot 1 comprises a base 11 installed on a mounting surface such as a floor, and a turntable 12 pivotally attached to the base 11 so as to be rotatable around a first axis A1 oriented perpendicular to the mounting surface. The output shaft of a first axis motor (not shown), which is fixed to the base 11, is connected to the turntable 12. This allows the turntable 12 to be rotated around the first axis A1 by driving the first axis motor. A first reduction gear (not shown) is attached to the output shaft of the first axis motor. The first axis motor and the first reduction gear are housed inside the base 11 and the turntable 12.

[0025] The collaborative robot 1 also includes a lower arm 13 pivotally mounted to the turntable 12 so as to be rotatable around a second axis A2, and a shoulder 14 pivotally mounted to the lower arm 13 so as to be rotatable around a third axis A3 parallel to the second axis A2. The base end of the lower arm 13 is pivotally mounted to the turntable 12 so as to be rotatable around the second axis A2 via a second axis motor (not shown). Here, the second axis A2 is an axis perpendicular to the first axis A1, but one of the two perpendicular axes may be offset so that these axes are in a torsional position. Powered by the second axis motor, the lower arm 13 rotates around the second axis A2 relative to the turntable 12. The second axis motor is housed inside the turntable 12. A second reduction gear (not shown) is attached to the output shaft of the second axis motor. The lower arm 13 is a cylindrical housing through which various cables (not shown) are inserted.

[0026] A portion of the shoulder 14 is pivotally attached to the lower arm 13 via a third-axis motor 31 (shown in Figure 3(B)) so as to be rotatable around the third axis A3. Powered by the third-axis motor 31, the shoulder 14 rotates relative to the lower arm 13 around the third axis A3. The third-axis motor 31 is housed inside the shoulder 14. A third reduction gear 33 (shown in Figure 3(B)) is attached to the output shaft of the third-axis motor 31.

[0027] Furthermore, the collaborative robot 1 includes an upper arm 15 pivotally attached to the shoulder 14 so as to be rotatable around a fourth axis A4 along the longitudinal direction, a support arm 16 pivotally attached at the tip of the upper arm 15 so as to be rotatable around a fifth axis A5 perpendicular to the fourth axis A4, and a tip member 17 that is rotatable around a sixth axis A6 along the longitudinal direction relative to the support arm 16. Here, the lower arm 13, the upper arm 15, and the support arm 16 are made of metal, for example, cast iron or aluminum alloy castings.

[0028] The base end of the upper arm 15 is pivotally attached to the shoulder 14 via a fourth-axis motor 41 (shown in Figure 3(B)) so as to be rotatable around the fourth axis A4. Here, the fourth axis A4 is an axis perpendicular to the third axis A3, but one of the two perpendicular axes may be offset, so that these axes are in a torsional position. Powered by the fourth-axis motor 41, the upper arm 15 rotates relative to the shoulder 14 around the fourth axis A4. The fourth-axis motor 41 is housed inside the shoulder 14. A fourth reduction gear 43 (shown in Figure 3(B)) is attached to the output shaft of the fourth-axis motor 41.

[0029] A portion of the support arm 16 is pivotally attached to the upper arm 15 via a fifth-axis motor 51, allowing it to rotate around the fifth axis A5. Here, the fifth axis A5 is an axis perpendicular to the fourth axis A4, but one of the two perpendicular axes may be offset, resulting in a torsional relationship between these axes. Powered by the fifth-axis motor 51, the support arm 16 rotates relative to the upper arm 15 around the fifth axis A5. The fifth-axis motor 51 is housed inside the shoulder 14. A torque converter 53 is attached to the output shaft of the fifth-axis motor 51 (output shaft 512 shown in Figure 2).

[0030] The end member 17, to which an end effector can be attached, is pivotally mounted to the support arm 16 via a sixth-axis motor 61 (shown in Figure 3(B)) so as to be rotatable around the sixth axis A6. Here, the sixth axis A6 is an axis perpendicular to the fifth axis A5, but one of the two perpendicular axes may be offset, so that these axes are in a torsional position. Powered by the sixth-axis motor 61, the end member 17 rotates around the sixth axis A6 relative to the support arm 16. The sixth-axis motor 61 is housed inside the support arm 16. A sixth reduction gear 63 (shown in Figure 3(B)) is attached to the output shaft of the sixth-axis motor 61.

[0031] Thus, in this embodiment, the collaborative robot 1 is equipped with motors 61 for each of its axes, from the first axis A1 to the sixth axis A6, which drive the axes around each axis.

[0032] Furthermore, the motor 51 for the fifth axis has a higher operating rate compared to the motors that drive the other axes. Therefore, the motor 51 for the fifth axis is relatively prone to deterioration over time, and it is necessary to replace or repair the motor 51 for the fifth axis regularly. For this reason, the following describes the configuration of the collaborative robot 1 that facilitates the replacement of the motor 51 for the fifth axis and the torque converter 53 that contributes to the conversion of the torque of the motor 51.

[0033] The upper arm 15 is a cylindrical housing and comprises an arm body 151 having an opening 2 for mounting the fifth-axis motor 51 and torque converter 53, and a cover 152 that covers the opening 2 and is attached to the arm body 151. The cover 152 is detachable from the arm body 151, and with the cover 152 removed, the fifth-axis motor 51 and torque converter 53 (more specifically, the gear case 535 shown in Figure 2) can be seen through the opening 2.

[0034] The opening 2 is formed in the upper arm 15, extending from the shoulder 14 side in a direction deviating from the intersection of the fourth axis A4 and the fifth axis A5 toward the support arm 16 side. Furthermore, as shown in Figure 2, when the upper arm 15 of the collaborative robot 1 according to this embodiment is viewed from a direction along the fifth axis A5 with the cover 152 removed, the opening 2 has a substantially elliptical shape to match the arrangement of the fifth axis motor 51 and torque converter 53 (more specifically, the gear case 535).

[0035] Viewed from a direction along the fifth axis A5 as shown in Figure 2, the fifth axis motor 51 and torque converter 53 are housed within the internal region of the opening edge 20 of the opening 2. The fifth axis motor 51 and torque converter 53 are connected to each other by a bracket 54. In this embodiment, the opening edge 20 refers to the inner edge that forms the opening 2.

[0036] With the above configuration, the motor 51 for the fifth axis and the torque converter 53 can be easily attached to and removed from the upper arm 15 via the opening 2 of the upper arm 15, along the fifth axis A5.

[0037] The configuration for easily removing the fifth-axis motor 51 and torque converter 53 will be explained in more detail below using Figures 2 to 4(B). Figure 3(A) is a view of the collaborative robot 1 shown in Figure 2 from a plane including the fourth axis A4 and the fifth axis A5. Figure 3(B) is a cross-sectional view showing part of the internal configuration of the collaborative robot 1 shown in Figure 3(A). Figures 4(A) and 4(B) are perspective views illustrating the method for removing the fifth-axis motor 51 from the arm body 151 of the collaborative robot 1 according to this embodiment. Note that in Figure 3(B), part of the internal configuration of the collaborative robot 1 is simply illustrated. Also, although Figure 1 shows the wiring connector of the fifth-axis motor 51, in Figures 2 and onward, the connector is actually connected to the fifth-axis motor 51 but is not shown.

[0038] The output shaft 512 of the fifth-axis motor 51, which rotates the support arm 16 around the fifth axis A5, is positioned along the fourth axis A4. Inside the upper arm 15 are the fifth-axis motor 51 and a torque converter 53 that converts the torque of the output shaft 512 into torque around the fifth axis A5. Since the output shaft 512 is housed in the bracket 54, the fifth-axis motor 51 is not visible externally even when the cover 152 is removed, as shown in Figure 2.

[0039] The torque converter 53 includes a pair of bevel gears 533 that adjust the direction of rotation of the fifth shaft motor 51, a fifth reduction gear 534 that adjusts the magnitude of rotation of the fifth shaft motor 51, and a gear case 535 that houses the pair of bevel gears 533 and has a plurality of insertion holes 531 (shown in Figure 4(B)) formed therein.

[0040] The pair of bevel gears 533 consists of a first bevel gear 533a and a second bevel gear 533b that mesh with each other at approximately 90 degrees. Since the first bevel gear 533a is connected to one end of the output shaft 512, the direction of rotation of the first bevel gear 533a coincides with the direction of rotation of the output shaft 512. Since the second bevel gear 533b is connected to one end of the inner shaft of the fifth reduction gear 534, it transmits the rotational torque of the first bevel gear 533a to the fifth reduction gear 534.

[0041] The gear case 535 includes a first housing section 535a and a second housing section 535b, which are integrally formed. The first housing section 535a houses the first bevel gear 533a and is fixed in contact with one end of a bracket 54 which has a substantially cylindrical shape. The second housing section 535b houses the second bevel gear 533b.

[0042] As shown in Figure 2, when viewed from the direction along the fifth axis A5, the fifth axis motor 51 and torque converter 53 are housed within the internal region of the opening edge 20, as previously described. Furthermore, the bracket 54 connecting the motor body 511 of the fifth axis motor 51 and the first housing portion 535a is also housed within the internal region of the opening edge 20. Also, when viewed from the direction along the fifth axis A5, a gap S1 is formed between the pair of side surfaces 513 of the motor body 511 along the direction of the fourth axis A4 and the opposing edge portions 200 of the opening edge 20 that face each side surface 513. This gap S1 is formed to widen as it proceeds along the fourth axis A4 from the shoulder 14 end 514 of the side surface 513 toward the torque converter 53.

[0043] In other words, the opposing edge portion 200 of the opening edge 20 bulges out when viewed from the direction along the fifth axis A5, and with this configuration, an operator can put their hand into the gap S1 between the opposing edge portion 200 and the fifth axis motor 51 and easily remove the fifth axis motor 51 from the opening 2 together with the bracket 54.

[0044] Furthermore, the fifth-axis motor 51 and torque converter 53 have protruding portions 510 and 530 that extend from the opening edge 20, as shown in Figure 3(A). This allows the fifth-axis motor 51 and torque converter 53 to be more easily removed from the opening 2 by gripping the protruding portions 510 and 530 or their vicinity.

[0045] Furthermore, as shown in Figure 2, four mounting holes 55 are formed around the fifth axis A5 in the internal region within the opening edge 20. The second housing 535b is fixed to the internal region within the opening edge 20 by screwing screws (not shown) into these mounting holes 55. By removing the screws from these mounting holes 55, the gear case 535 and the second bevel gear 533b housed in the second housing 535b can be removed from the opening 2.

[0046] Furthermore, as shown in Figure 3(B), the torque converter 53 is fixed to the arm body 151, and the fifth-axis motor 51 is suspended from the torque converter 53 (more specifically, the first housing portion 535a of the gear case 535) via a bracket 54 that houses the output shaft 512 of the fifth-axis motor 51. As a result, a gap S2 is formed inside the arm body 151 below the motor body 511 in a plan view formed by the third axis A3 and the fourth axis A4 shown in Figure 3(B), and the fifth-axis motor 51 can be easily removed from the opening 2 together with the bracket 54 by an operator reaching into this gap S2. In addition, a space is formed around the fifth-axis motor 51 by the gap S1 shown in Figure 2 and the gap S2 shown in Figure 3(B), which improves heat dissipation when the fifth-axis motor 51 rotates.

[0047] Furthermore, within the support arm 16, in a plan view of the third axis A3 and fourth axis A4 shown in Figure 3(B), the sixth axis motor 61 is positioned below the fifth reduction gear 534 of the torque converter 53. The end member 17 rotates around the sixth axis A6 relative to the support arm 16 by the sixth axis motor 61. The output shaft of the sixth axis motor 61 extends toward the end member 17, and the sixth reduction gear 63 is attached to this output shaft.

[0048] As previously described, the first housing section 535a, which houses the first bevel gear 533a, is fixed to the bracket 54. Specifically, as shown in Figure 4(A), only the protruding portion 530 of the torque converter 53 (more specifically, the first housing section 535a) is attached to the bracket 54 via the fixing device 3. The protruding portion 530 and the bracket 54 have multiple (for example, four each) insertion holes 531 and 541 formed in a direction along the fourth axis A4 into which the fixing device 3 is inserted. Note that in Figure 4(A), only the insertion holes 531 of the protruding portion 530 and the bracket 54 are shown, but in reality, the first housing section 535a is fixed to the bracket 54 by inserting the fixing device 3 into these insertion holes while the insertion holes 531 and 541 overlap.

[0049] With the above configuration, when the collaborative robot 1 is in operation, the fifth-axis motor 51 and the torque converter 53 can be fixed together via the fixing device 3. Furthermore, since the motor body 511 of the fifth-axis motor 51 is screwed to the bracket 54, the fifth-axis motor 51 can be easily removed from the opening 2 together with the bracket 54 by removing the fixing device 3 from the insertion holes 531 and 541 using a tool such as a screwdriver, as shown in Figure 4(B). Subsequently, the torque converter 53 can also be easily removed from the opening 2 by pulling it out along the fifth axis A5. Here, as an example, the fixing device 3 is a screw, and the insertion holes 521 and 531 are screw holes.

[0050] Returning to the explanation of Figure 3(B), the shoulder 14 houses the fourth-axis motor 41 that rotates the upper arm 15 around the fourth axis A4. Inside the upper arm 15, on the side of the shoulder 14 that is closer to the fifth-axis motor 51, there is a cavity C that houses the wiring W connected to the fifth-axis motor 51. The wiring W passes from the fifth-axis motor 51 through the cavity C and is then inserted into the shafts of the fourth reduction gear 43 of the fourth-axis motor 41 and the third reduction gear 33 of the third-axis motor 31. The third reduction gear 33 and the fourth reduction gear 43 are positioned such that the longitudinal directions of their respective shafts are approximately 90 degrees apart.

[0051] With the above configuration, since the fourth-axis motor 41 is not located in the cavity C, the wiring W housed in the cavity C does not get caught on the fourth-axis motor 41. Therefore, excess length wiring W can be housed in the cavity C, the fifth-axis motor 51 can be removed from the opening 2, and the housed excess length wiring W can be smoothly pulled out from the opening 2.

[0052] Figures 5(A) and 5(B) are cross-sectional views of the arm body 151 of the collaborative robot 1 according to this embodiment, perpendicular to the fourth axis A4. Figure 5(A) is a cross-sectional view including the opening edge 20 of the opening 2, and Figure 5(B) is a cross-sectional view of the opening 2 excluding the opening edge 20. In the cross-section perpendicular to the fourth axis A4, the thickness t1 of the opening edge 20 is thicker than the thickness t2 of the other parts. This ensures the bending strength of the upper arm 15 (arm body 151), including the opening edge 20, when the cover 152 is removed. Here, thickness refers to the thickness in the radial direction centered on the fourth axis A4 in the cross-section perpendicular to the fourth axis A4.

[0053] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design modifications can be made without departing from the spirit of the invention as described in the claims. [Explanation of symbols]

[0054] 1: Collaborative robot, 11: Base, 12: Turntable, 13: Lower arm, 14: Shoulder, 15: Upper arm, 151: Arm body, 152: Cover, 16: Support arm, 17: End piece, 2: Opening, 20: Opening edge, 200: Opposing edge, 3: Fixing device, 41: Motor for 4th axis, 51: Motor for 5th axis, 511: Motor body, 512: Output shaft, 513: Side view, 514: End, 53: Torque converter, 510-530: Protruding part, 531-541: Insertion hole, 54: Bracket, A1-A6: 1st axis-6th axis, S1: Gap

Claims

1. A swivel base is pivotally attached to the base so as to be rotatable around the first axis, A lower arm is pivotally attached to the aforementioned turntable so as to be rotatable around a second axis, A shoulder is pivotally attached to the lower arm so as to be rotatable around a third axis parallel to the second axis, An upper arm is pivotally attached to the shoulder so as to be rotatable around a fourth axis along the longitudinal direction, At the tip of the upper arm, a support arm is pivotally attached so as to be rotatable around a fifth axis perpendicular to the fourth axis, A collaborative robot comprising a support arm and an end member that is rotatable about a sixth axis along the longitudinal direction, With the output shaft of the fifth-axis motor, which rotates the support arm around the fifth axis, positioned along the fourth axis, the upper arm houses the fifth-axis motor and a torque converter that converts the torque of the output shaft into torque around the fifth axis. The upper arm is a cylindrical housing comprising an arm body having an opening for mounting the fifth-axis motor and the torque converter, and a cover that covers the opening and is attached to the arm body. A collaborative robot characterized in that, when viewed from a direction along the fifth axis, the motor for the fifth axis and the torque converter are housed in an internal region within the opening edge of the opening.

2. The collaborative robot according to claim 1, characterized in that the motor for the fifth axis and the torque converter have protruding portions that protrude from the opening edge of the opening.

3. The aforementioned fifth-axis motor has a motor body, When viewed from a direction along the fifth axis, a gap is formed between the pair of sides of the motor body along the direction of the fourth axis and the opposing edge of the opening that faces each of the aforementioned sides. The collaborative robot according to claim 1, characterized in that the gap is formed such that it widens from the shoulder end of the side surface as it proceeds along the fourth axis toward the torque converter.

4. The torque converter is fixed to the arm body, The collaborative robot according to claim 2, characterized in that the fifth-axis motor is fixed in a suspended state to the torque converter via a bracket that houses the output shaft of the fifth-axis motor.

5. The protruding portion of the torque converter is attached to the bracket via a fixing device. The collaborative robot according to claim 4, characterized in that the protruding portion of the torque converter and the bracket have insertion holes formed in a direction along the fourth axis into which the fixing device is inserted.

6. The collaborative robot according to claim 1, characterized in that, in a cross-section perpendicular to the fourth axis, the thickness of the opening edge of the opening is greater than the thickness of other parts.

7. The shoulder houses a fourth-axis motor that rotates the upper arm around the fourth axis. The collaborative robot according to claim 1, characterized in that a cavity for housing wiring connected to the fifth axis motor is formed inside the upper arm on the shoulder side of the fifth axis motor.

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