JP2004249413A - Robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for adjusting rotational torque with a simple and lightweight constitution. <P>SOLUTION: This robot 10 has an end side member 14 rockable to a body side member 12, a first rotary means 33 for rocking the end side member 14, and a second rotary means 25 for rotating the first rotary means 33 itself. In the robot 10, the end side member 14 rocks by rotating the first rotary means 33. The first rotary means 33 itself is rotated by the second rotary means 25. Rocking torque of the end side member 14 can be adjusted by combinedly using rotation of the first rotary means 33 and rotation of the second rotary means 25. The device constitution is simple, and can be reduced in weight. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot. In particular, the present invention relates to a technique of swinging a distal member with respect to a body member.
[0002]
2. Description of the Related Art There is known a robot provided with a body-side member, a distal-side member swingable with respect to the body-side member by a joint, and an actuator for swinging the distal-side member.
The robot performs various operations by swinging the distal member relative to the body member. At this time, the torque required to swing the distal member changes variously. For example, when walking on level ground, a relatively small torque is required to rotate the knee joint, while a large torque is required to rotate the knee joint when climbing stairs. A large torque is required to rotate the arm holding the heavy object around the shoulder joint, but a small torque is sufficient to rotate only the arm around the shoulder joint. There is a case where an actuator cannot cope with a large change in required torque, and a technique of incorporating a multi-stage transmission capable of changing a gear ratio between an actuator and a joint has been proposed in Patent Document 1.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 5-146978
However, since the multi-stage transmission has a plurality of gear systems and requires an actuator for switching the gear systems, the multi-stage transmission has to be complicated. For this reason, the weight and cost of the robot are increased.
[0005]
The present invention has been made to solve such a problem, and an object of the present invention is to provide a technique capable of adjusting a rotational torque with a simple and lightweight configuration.
[0006]
The robot created by the present invention comprises a distal member swingable with respect to the body member, a first rotating means for rocking the distal member, A second rotating means for rotating the first rotating means itself is provided.
In the robot described above, the distal end member swings as the first rotating means rotates. The first rotating means itself is rotated by the second rotating means. By using the rotation of the first rotation unit and the rotation of the second rotation unit in combination, it is possible to adjust the swing torque of the distal end member. The device configuration is simple and can be reduced in weight.
[0007]
In the robot, it is preferable that the housing of the first rotating means is rotatably supported by the body-side member, and the housing of the second rotating means is supported by the body-side member so as not to rotate. By attaching the first rotating means and the second rotating means to the body side member, the weight of the distal side member can be reduced, and the energy required for swinging the distal side member can be reduced.
[0008]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The main features of the embodiment described later will be described.
(Feature 1) A thigh member and a lower leg member are rotatably connected by a knee joint.
(Mode 2) The second motor is fixed to the thigh member. A second pulley is fixed to a drive shaft of the second motor. Further, a driven pulley is rotatably attached to the thigh member. A first motor is attached to the driven pulley. A belt is wound around the second pulley and the driven pulley. A first pulley is fixed to a drive shaft of the first motor.
[0009]
An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, in the present embodiment, the present invention is applied to a knee joint 10 connecting a thigh member 12 and a lower leg member 14 of a robot 11.
FIG. 2 shows details of the knee joint 10. FIG. 3 is a sectional view taken along line III-III of FIG. As shown in FIG. 3, a circular through hole 27 is formed in the thigh member 12. Further, a bearing 28 is attached to the through hole 27. The bearing 28 is retained by a retaining ring 29 attached to the thigh member 12 with a screw 30. A rotating ring 39 is mounted on the inner ring of the bearing 28. The driven pulley 34 is fixed to the rotating ring 39 by the screw 31. The housing of the first motor 33 is attached to the rotating ring 39 by a screw 32. A slip ring is provided on the outer periphery of the housing of the first motor 33, and the power supply electrode 71 is in sliding contact with the slip ring. The rotating ring 39, the driven pulley 34, and the first motor 33 rotate integrally with the thigh member 12. The first motor 33 is controlled by a controller (not shown).
[0010]
A bracket 22 is attached to the thigh member 12 with a screw 23. The housing of the second motor 25 is fixed to the bracket 22 by a screw 24. A second pulley 26 is fixed to a drive shaft 25a of the second motor 25. The second motor 25 is controlled by a controller (not shown). A first pulley 36 is fixed to the drive shaft 33a of the first motor 33. The first motor 33 is controlled by a controller (not shown).
As shown in FIG. 4, a belt 35 is wound around the second pulley 26 and the driven pulley 34.
[0011]
As shown in FIG. 3, a support block 48 is attached to a lower end surface 12 a of the thigh member 12 by a screw 49. The ring 44 and the circular spline 52 a of the harmonic drive (trade name) 52 are fixed to the support block 48 by a screw 53. The rotating ring 44 supports a shaft 46 via a bearing 45 mounted on the inner peripheral side. A third pulley 47 is fixed to the shaft 46. As shown in FIG. 2, a belt 50 is wound around the first pulley 36 and the third pulley 47.
The shaft 46 is fixed to the wave generator 52b of the harmonic drive 52. The harmonic drive 52 is a speed reducer, and has a function of reducing the number of revolutions of the wave generator 52b and transmitting it to the flex spline 52c. Since the harmonic drive 52 is publicly known, further description is omitted.
[0012]
One end 55 a of a shaft 55 is fixed to the flex spline 52 c of the harmonic drive 52 by a screw 54. A ring 56 is fixed to the other end 55 b of the shaft 55 by a screw 57. The ring 56 is fixed to the lower leg member 14 by a screw 64. The lower leg member 14 is swingably supported by the thigh portion 12 via the ring 44 and the support block 48 by the bearings 43, 61, and 62. The lower leg member 14 swings with respect to the thigh portion 12 around the shafts 46 and 55.
[0013]
When the drive shaft 33a of the first motor 33 rotates, the first pulley 36 also rotates. When the first pulley 36 rotates, the third pulley 47 rotates via the belt 50. As shown in FIG. 2, the diameter of the first pulley 36 is smaller than that of the third pulley 47. For this reason, the rotation speed of the third pulley 47 is lower than that of the first pulley 36.
When the third pulley 47 rotates, the wave generator 52b of the harmonic drive 52 rotates together with the shaft 46, and the rotation speed is reduced and transmitted to the flex spline 52c. When the flex spline 52c rotates, the shaft 55 and the ring 56 rotate integrally. When the ring 56 rotates, the crus member 14 rotates with respect to the thigh member 12. When the drive shaft 33a of the first motor 33 rotates forward, the lower leg member 14 swings forward, and when the first motor 33 rotates reversely, the lower leg member 14 swings rearward.
[0014]
When the drive shaft 25a of the second motor 25 rotates, the second pulley 26 also rotates. When the second pulley 26 rotates, the driven pulley 34 rotates via the belt 35. The driven pulley 34 rotates integrally with the housing of the first motor 33. Therefore, when the rotation speed of the drive shaft 25a of the second motor 25 changes while the first motor 33 is rotating, the rotation speed and the rotation torque of the drive shaft 33a of the first motor 33 in the absolute space are adjusted. . For example, when the rotation speed of the drive shaft 25a of the second motor 25 increases, the rotation speed and the rotation torque of the drive shaft 33a of the first motor 33 increase. When the rotation speed and the rotation torque of the drive shaft 33a of the first motor 33 are adjusted, the rotation speed and the rotation torque of the third pulley 47 are adjusted. When the rotation speed and the rotation torque of the third pulley 47 are adjusted, the swing speed and the swing torque of the lower leg member 14 with respect to the thigh member 12 are adjusted.
[0015]
According to the above-described configuration, the swing speed and the swing torque of the lower leg member 14 and the like can be adjusted with a simple configuration as compared with a gear switching type transmission. Therefore, the weight and cost of the robot 11 can be reduced as compared with the case where a gear-type multi-stage transmission having a complicated configuration is mounted. Further, when a gear type multi-stage transmission is used, the swing speed and the swing torque of the lower leg member 14 and the like suddenly change with the switching of the gear system. However, according to the present embodiment, the second motor 25 By adjusting the number of rotations, the swing speed and swing torque of the crus member 14 can be adjusted smoothly (steplessly).
Further, when the distal member can swing slightly with respect to the body member, only the first motor 33 can be used, and when the torque is insufficient, the second motor 25 can assist. According to the multi-stage transmission, the oscillating speed must be reduced as the torque increases. However, according to the method of assisting with the second motor, the torque can be increased without lowering the oscillating speed. Both the swing speed and the swing torque can be increased.
[0016]
As mentioned above, although the specific example of this invention was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and alterations of the specific examples illustrated above. The torso side member and the distal side member are not limited to the thigh and the lower leg, but the torso and the thigh (hip joint), the lower leg and the toe (ankle joint), the torso and the upper arm (shoulder joint), and the upper arm It can be used for the lower arm (elbow joint) and the like.
Further, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.
Therefore, for example, it can be configured as described below.
[0017]
(1) Instead of the belt 35 transmitting the rotation of the second motor 25 to the first motor 33 and the belt 50 transmitting the rotation of the first motor 33 to the lower leg member 14, a gear may be used. Since the gear does not expand or bend like a belt, rotation can be transmitted more reliably.
(2) The rotation directions of the second motor 25 and the first motor 22 need not be the same. The rotation of the first motor can be reduced by rotating the second motor in a direction opposite to the direction in which the first motor 33 is rotating.
[Brief description of the drawings]
FIG. 1 shows a robot according to an embodiment.
FIG. 2 shows a knee joint according to the embodiment.
FIG. 3 is a sectional view taken along line III-III of FIG. 2;
FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;
[Explanation of symbols]
10: knee joint 11: robot 12: thigh member, 12a: lower end surface 14: lower leg member 22: brackets 23, 24: screw 25: second motor, 25a: drive shaft 26: second pulley 27: through hole 28: Bearing 29: retaining rings 30, 31, 33: screw 33: first motor, 33a: drive shaft 34: driven pulley 35: belt 36: first pulley 39: rotating ring 43: bearing 44: rotating ring 45: bearing 46: Shaft 47: Third pulley 48: Support block 49: Screw 50: Belt 52: Harmonic drive, 52a: Circular spline, 52b: Wave generator, 52c: Flex spline 53, 54: Screw 55: Shaft, 55a: One end, 55b: Other end 56: Ring 61, 62: Bear Packaging 64: screw 71: electrode

Claims (2)

A body-side member, a terminal-side member swingable with respect to the body-side member, a first rotating unit for swinging the terminal-side member, and a second rotating unit for rotating the first rotating unit itself; A robot characterized by the following. The robot according to claim 1, wherein the housing of the first rotating means is rotatably supported by the body-side member, and the housing of the second rotating means is non-rotatably supported by the body-side member.

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