Robot

Abstract

A robot (1) is provided with: a first wrist element (5) supported at the tip of an arm (2) so as to be rotatable about a first axis (A); a second wrist element (6) supported so as to be rotatable relative to the first wrist element (5) about a second axis (B) orthogonal to the first axis (A); and a third wrist element (7) supported so as to be rotatable relative to the second wrist element (6) about a third axis (C) orthogonal to the second axis (B), the first wrist element (5) being provided with a first space (10) that accommodates a first motor (9) that drives the second wrist element (6) and a second motor (8) that drives the third wrist element (7), and a second space (11, 12) that accommodates a second motor (8) that drives the third wrist element (7). The second spaces (11, 12) communicate with the first space (10) and are disposed on both sides of the first space (10) in the direction of the second axis (B), and the linear body (26) guided inside the arm (2) is guided to the first space (10) via at least one second space (12).

Description

Technical Field

[0001] The present disclosure relates to a robot. Background Art

[0002] A robot is known in which a motor for a front two-axis wrist element is mounted in a three-axis wrist unit disposed at the front end of the arm (for example, see Reference Document 1). In this robot, the motor mounted on the wrist unit is exposed outside the housing of the wrist unit, and the cable connected to the motor is also exposed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Comparative Document 1: Japanese Patent Application Publication No. 2012-240123 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] Since the wrist unit may be exposed to liquid when handling a workpiece, the motor is preferably contained in the housing in a sealed state. In addition, since the wrist unit moves close to the workpiece, it is preferred to contain cables and the like in the housing to avoid interference with the workpiece and the like.

[0008] However, it is necessary to ensure the following space inside the housing of the wrist unit: a space for arranging a transmission mechanism for transmitting the power of the motor to the wrist element. Therefore, the space for arranging wire bodies such as cables tends to become narrow, and the fixing work in the housing is difficult. Therefore, it is desired to achieve miniaturization of the wrist unit while routing wire bodies such as cables in the housing without difficulty.

[0009] Solutions for solving problems

[0010] One aspect of the present disclosure is a robot comprising: a first wrist element, which is supported at the front end of an arm in a manner capable of rotating around a first axis; a second wrist element, which is supported to be capable of rotating relative to the first wrist element around a second axis orthogonal to the first axis; and a third wrist element, which is supported to be capable of rotating relative to the second wrist element around a third axis orthogonal to the second axis, the first wrist element comprising a first space and a second space, the first space accommodating a first motor that drives the second wrist element and a second motor that drives the third wrist element, the second space being connected to the first space and being arranged on both sides of the first space in the direction of the second axis, the linear body guided in the arm is guided to the first space via at least one side of the second space. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1A partial longitudinal sectional view of a robot according to an embodiment of the present disclosure is shown.

[0012] Figure 2 To show Figure 1 A partial longitudinal sectional view of a robot in a state where a cover component is removed.

[0013] Figure 3 Observed from one side along the second axis Figure 2 Figure 2 shows the robot with the cover assembly removed.

[0014] Figure 4 To observe from the other side of the second axis Figure 2 Figure 2 shows the robot with the cover assembly removed. DETAILED DESCRIPTION

[0015] Hereinafter, a robot 1 according to an embodiment of the present disclosure will be described with reference to the drawings.

[0016] The robot 1 of this embodiment is, for example, a vertical multi-joint robot. Figure 1 As shown, the robot 1 includes a three-axis wrist unit 3 disposed at the front end of an arm 2. The arm 2 and the wrist unit 3 are connected via a speed reducer 4.

[0017] The wrist unit 3 includes a first wrist element 5 supported by a reducer 4 so as to be rotatable relative to the arm 2 about a first axis A. In addition, the wrist unit 3 includes a second wrist element 6 supported so as to be rotatable relative to the first wrist element 5 about a second axis B orthogonal to the first axis A.

[0018] The wrist unit 3 also includes a third wrist element 7 supported rotatably relative to the second wrist element 6 about a third axis C that is perpendicular to the second axis B. The third axis C is disposed in a plane that includes the first axis A and is orthogonal to the second axis B.

[0019] The first wrist element 5 is formed hollow. The first wrist element 5 has a first space 10 inside for accommodating two motors (first motor and second motor) 8 and 9. In addition, the first wrist element 5 has two second spaces 11 and 12, which are arranged on both sides of the first space 10 in the direction of the second axis B.

[0020] The arm 2 is formed hollow and includes a hollow tube 13 extending along the first axis A. The front end of the hollow tube 13 opens into the first space 10 of the first wrist element 5 .

[0021] like Figure 2As shown, the first wrist element 5 includes cover members 14 on both sides of the second axis B direction that can be detached along the second axis B. By removing the cover members 14, the second spaces 11 and 12 of the first wrist element 5 can be exposed to the outside. By installing the cover members 14, the second spaces 11 and 12 can be sealed.

[0022] The first wrist element 5 includes a plate-shaped partition wall 15 that partially partitions the first space 10 from each of the second spaces 11, 12. Each partition wall 15 includes a threaded hole 17 for fixing the motors 8, 9 to the first space side by a bolt 16, and a through hole 18 that penetrates in the plate thickness direction. The first space 10 and the second space 11, 12 are connected to each other at a portion other than the partition wall 15.

[0023] Each motor 8, 9 is fixed to the partition wall 15 in a state where the shaft 8a, 9a passes through the through hole 18 of the partition wall 15. The main body of the motor 8, 9 is arranged in the first space 10, and a gap is formed between the side surface of the main body and the inner wall of the first wrist element 5. The motor (first motor) 9 drives the second wrist element 6, and the motor (second motor) 8 drives the third wrist element 7.

[0024] The shafts 8a and 9a of the motors 8 and 9 that pass through the through hole 18 of the partition wall 15 protrude from the partition wall 15 toward the second spaces 11 and 12. Pulleys 19 are fixed to the shafts 8a and 9a.

[0025] The second wrist element 6 is located at the front end side of the first wrist element 5, between the two front end portions 5a, 5b that are bifurcated toward the front end. Each of the front end portions 5a, 5b is formed hollow and communicates with the second spaces 11, 12 on both sides of the first space 10. The second wrist element 6 is supported by the two front end portions 5a, 5b on both sides of the second axis B direction so as to be rotatable around the second axis B.

[0026] A speed reducer 20 is fixed between the second wrist element 6 and one distal end 5a, and the speed reducer 20 drives the second wrist element 6 to rotate relative to the first wrist element 5. The second wrist element 6 and the other distal end 5b are rotatably mounted via a bearing (not shown).

[0027] An input shaft 21 of the speed reducer 20 protrudes from one of the front end portions 5a. An input shaft 23 of the speed reducer 22 that drives the third wrist element 7 to rotate relative to the second wrist element 6 protrudes from the other front end portion 5b.

[0028] The power input to the input shaft 23 is input to the speed reducer 22 via a gear pair (not shown). A pulley 24 is fixed to each of the input shafts 21 and 23, respectively.

[0029] A belt 25 is laid between the pulley 24 of the input shaft 21 and the pulley 19 of the shaft 9a of the motor 9. A belt 25 is also laid between the pulley 24 of the input shaft 23 and the pulley 19 of the shaft 8a of the motor 8.

[0030] The pair of pulleys 19 and 24 and the belt 25 constitute a power transmission mechanism (first power transmission mechanism and second power transmission mechanism) for transmitting the power of the motors 8 and 9 to the speed reducers 22 and 20, respectively. The power transmission mechanism is located in the second spaces 11 and 12.

[0031] like Figure 3 and Figure 4 As shown, the outer diameters of the pulleys 19 and 24 are sufficiently smaller than the cross-sectional shapes of the motors 8 and 9. A space S extending in the first axis A direction exists outside the belt 25 stretched between the pulleys 19 and 24 in the second spaces 11 and 12.

[0032] The space S has a width larger than 1 / 2 of the difference between the width of the motors 8 and 9 and the outer diameter of the pulleys 19 and 24. The space S has a dimension in the second axis B direction that is sufficiently larger than the thickness of the pulleys 19 and 24.

[0033] Linear bodies 26 such as cables for supplying power and signals to motors 8 and 9 enter the first wrist element 5 from the arm 2 side through the hollow tube 13. Figure 1 As shown, the umbilical body 26 coming out of the opening at the front end of the hollow tube 13 enters the first space 10 of the first wrist element 5. A part of the umbilical body 26 is connected to the motor 8 located in the front side when viewed from the arm 2 side in the first space 10.

[0034] The remaining filament 26 passes through the narrow gap between the side wall of the motor 8 and the inner surface of the first wrist element 5 in the first space 10, and is pulled out into the second space 11 on one side. Furthermore, the filament 26 pulled out into the second space 11 passes through the space S outside the pulley 19 and the belt 25 on the second space 11 side of the partition wall 15.

[0035] When passing through the space S, the linear body 26 is held on the second space 11 side of the partition wall 15 by sheet metal and a strapping tape (holding member 27). The shape and holding method of the holding member 27 may be any method other than sheet metal and a strapping tape. Afterwards, the linear body 26 bends toward the first space 10 side at a position beyond the partition wall 15 on the front end 5a side, and enters the first space 10 again.

[0036] The filament body 26 entering the first space 10 is held by a holding member 28 further inside the motor 9 as viewed from the arm 2. The holding member 28 may be fixed by any fixing method such as sheet metal or a strapping tape. In addition, a portion of the filament body 26 is connected to the motor 9 on the inside.

[0037] The remaining line body (such as an air tube) 26 passes through the first space 10 and enters the other second space 12. Then, it returns to the first space 10 from the second space 12 and is connected to a joint or connector (not shown) provided on the first wrist element 5.

[0038] Next, the operation of the robot 1 according to the present embodiment configured as described above will be described.

[0039] A portion of the umbilical body 26 that has entered the first space 10 from the hollow tube 13 passes through a narrow gap between the motor 8 and the inner surface of the first wrist element 5 .

[0040] The filament body 26 passing through the gap enters the second space 11 from the first space 10. In the second space 11, since the pulleys 19, 24 and the belt 25 as the power transmission mechanism are arranged in an exposed manner, the filament body 26 is usually not arranged near the power transmission mechanism.

[0041] However, the gap between the motors 8 and 9 and the inner surface of the first wrist element 5 is relatively narrow, and it is difficult to reliably fix the umbilical body 26 in the gap.

[0042] According to the present embodiment, the motors 8 and 9 are fixed to the first space 10 side of the flat plate-shaped partition wall 15 that partially partitions the first space 10 from the second spaces 11 and 12 .

[0043] Thus, pulleys 19 and 24 and belt 25 as a power transmission mechanism are arranged on the second spaces 11 and 12 of the partition wall 15 , and a space S extending along the first axis A is formed outside the power transmission mechanism. The linear body 26 is arranged along the space S and fixed on the second space 11 of the partition wall 15 .

[0044] Thus, the umbilical body 26 can be arranged by utilizing the second space 11 formed for arranging the power transmission mechanism.

[0045] The second spaces 11 and 12 are spaces that can be widely opened by removing the cover member 14. Therefore, the motors 8 and 9 can be easily attached and detached, the pulleys 19 and 24 and the belt 25 can be adjusted, and the umbilical body 26 can be attached and detached.

[0046] In addition, since the umbilical body 26 is only passed through between the motors 8 and 9 and the inner surface of the first wrist element 5 without being fixed, the gap can be minimized. As a result, the first wrist element 5 can be made thinner.

[0047] Furthermore, a portion of the filament body 26 that enters the first space 10 through the hollow tube 13 is routed to the motor 9 and the like in the first space 10 after passing through the second space 11. Thus, the wide space that combines the first space 10 and the second space 11 that are interconnected can be utilized to ensure a large bending radius of the filament body 26. That is, by utilizing the wide space to greatly bend the filament body 26, the burden imposed on the filament body 26 can be reduced, and routing can be performed without difficulty.

[0048] Furthermore, another part of the linear body 26 enters the second space 11 on one side from the first space 10, and passes through the first space 10 again to enter the second space 12 on the other side. And, it returns to the first space 10 again from the second space 12. Thus, the linear body 26 can be greatly bent in a wider space that combines the first space 10 and the two second spaces 11 and 12 on both sides thereof.

[0049] That is, the robot 1 of this embodiment utilizes the space S in the second space 11 provided for configuring the power transmission mechanism. Since the cross-sectional dimension of the space S is sufficiently larger than the gap between the motor 8 and the inner surface of the first wrist element 5, the filament body 26 does not interfere with the surrounding inner wall.

[0050] Furthermore, there is no need to specially provide a space S for wiring the umbilical body 26. Moreover, the wiring work of the umbilical body 26 can be facilitated by opening and closing the cover member 14 for opening the second spaces 11 and 12. Furthermore, there is an advantage that the wrist unit 3 can be miniaturized.

[0051] In this embodiment, the umbilical body 26 is held by the holding member 27 on the second space 11 side, but the present invention is not limited thereto. The umbilical body 26 may be pulled out into the second space 12 and held by the holding member 27 on the second space 12 side.

[0052] Description of reference numerals:

[0053] 1: Robot

[0054] 2: Arm

[0055] 5: First wrist component

[0056] 6: Second wrist component

[0057] 7: Third wrist component

[0058] 8: Motor (second motor)

[0059] 9: Motor (first motor)

[0060] 14: Cover parts

[0061] 15: Partition wall

[0062] 19, 24: Pulley (first power transmission mechanism, second power transmission mechanism)

[0063] 25: Belt (first power transmission mechanism, second power transmission mechanism)

[0064] 26: Lines

[0065] 27: Keep the parts

[0066] 10: First Space

[0067] 11, 12: Second Space

[0068] A: First axis

[0069] B: Second axis

[0070] C: The third axis

Claims

1. A robot, characterized in that: have: a first wrist element supported at a front end of the arm in a manner capable of rotating about a first axis; a second wrist element supported to be rotatable relative to the first wrist element about a second axis orthogonal to the first axis; as well as a third wrist element supported to be rotatable relative to the second wrist element about a third axis orthogonal to the second axis, The first wrist element includes a first space and a second space, the first space accommodating a first motor driving the second wrist element and a second motor driving the third wrist element, the second space communicating with the first space and being arranged on both sides of the first space in the direction of the second axis. The linear body guided in the arm is guided to the first space via the second space on at least one side.

2. The robot according to claim 1, characterized in that: The second space accommodates a first power transmission mechanism and a second power transmission mechanism, respectively. The first power transmission mechanism transmits the power of the first motor to the second wrist element, and the second power transmission mechanism transmits the power of the second motor to the third wrist element.

3. The robot according to claim 1 or 2, characterized in that: The robot includes a plate-shaped partition wall, the partition wall partially partitions the first space and each of the second spaces, and the first motor or the second motor is fixed to the partition wall. The umbilical body passing through the second space is held on the partition wall by a holding member.

4. The robot according to claim 3, characterized in that: The first wrist element includes a cover member that is detachably mounted along the second axis direction, and the second space is opened by removing the cover member.

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