JP2020146774A - robot - Google Patents

Abstract

To provide a robot that can attenuate external force such as impact received by an arm, so as to reduce breakage of a motor, a speed reducer and the like.SOLUTION: A robot 2 comprises a second member (an arm 22) that turns around a turning shaft with respect to a first member (a base 21) and a motor unit (an arm driving part 26) that turns the second member. The motor unit has: a motor (a first motor 261) having a rotary shaft 263; a first rotation part 50 connected to the rotary shaft; a second rotation part 60, connected to the second member, which rotates along a rotating direction of the first rotation part; a plurality of rotating bodies 41 arranged between the first rotation part and the second rotation part; and elastic bodies (metal plate springs 42) arranged between the rotating bodies and the first rotation part or between the rotating bodies and the second rotation part.SELECTED DRAWING: Figure 2

Description

The present invention relates to a robot.

Conventionally, as a robot for transporting parts and the like, for example, Patent Document 1 discloses a horizontal articulated robot also called a SCARA robot. The robot described in Patent Document 1 includes a base, a first arm connected to the upper end of the base and rotating with respect to the base about an axis along the vertical direction, a motor, and a deceleration. It has a machine and the like, and is provided with a motor drive unit as a motor unit for rotating the first arm.

Japanese Unexamined Patent Publication No. 2018-130796

However, in the robot described in Patent Document 1, when an external force such as an impact is applied to the first arm, there is a possibility that the motor or the speed reducer constituting the motor drive unit may be damaged.

The robot of the present application includes a first member, a second member that rotates about a rotation axis with respect to the first member, and a motor unit that rotates the second member. A motor having a rotating shaft, a first rotating portion connected to the rotating shaft, and a second rotating portion rotating along the rotation direction of the first rotating portion and connected to the second member. A plurality of rotating bodies arranged between the first rotating portion and the second rotating portion, and between the rotating body and the first rotating portion, or between the rotating body and the second rotating portion. It has an elastic body arranged in.

In the above-mentioned robot, a rotating bearing portion may be provided between the first rotating portion and the second rotating portion at a position different from the arrangement position of the rotating body.

In the above-mentioned robot, an angle sensor for measuring the rotation position of the second rotating portion may be provided.

In the above-mentioned robot, the first rotating portion or the second rotating portion may be provided with a concave holding portion for holding the rotating body so as to be rotatable and slidable.

In the above-mentioned robot, the elastic body may be made of a metal leaf spring.

In the robot described above, the metal leaf spring may have a base material portion along the first rotating portion and a bent portion curved from the base material portion to hold the rotating body. Good.

In the robot described above, the first rotating portion or the second rotating portion may be provided with a groove for inserting the top of the bent portion of the metal leaf spring.

In the robot described above, the distance between the base material portion of the metal leaf spring and the surface of the first rotating portion or the second rotating portion facing the metal leaf spring is the first rotating portion or the said. It may be shorter than the protrusion distance of the rotating body from the second rotating portion.

The schematic which shows the whole structure of a robot. The cross-sectional view which shows the schematic structure of the connection part of the motor unit and the arm of the robot which concerns on 1st Embodiment. The QQ cross-sectional view of FIG. 2 shows the connection configuration between the first rotating portion and the second rotating portion. An enlarged cross-sectional view showing the arrangement configuration of the rotating body and the metal leaf spring and viewed from the same direction as in FIG. The front sectional view of FIG. 4 shows the arrangement configuration of a rotating body and a metal leaf spring. The schematic diagram explaining the process of reducing an external force. The cross-sectional view which shows the schematic structure of the connection part of the motor unit and the arm of the robot which concerns on 2nd Embodiment. An enlarged cross-sectional view showing the arrangement configuration of the rotating body and the metal leaf spring at the same position as in FIG. The front sectional view of FIG. 8 shows the arrangement configuration of a rotating body and a metal leaf spring. An enlarged cross-sectional view similar to FIG. 4 showing a modified example of the arrangement configuration of the rotating body and the metal leaf spring.

Hereinafter, the robot of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings. It should be noted that the present embodiment described below does not unreasonably limit the content of the present invention described in the claims. Moreover, not all of the configurations described in the present embodiment are essential constituent requirements of the present invention.

Further, in the drawings referred to below, for convenience of explanation, three axes orthogonal to each other, the X-axis, the Y-axis, and the Z-axis, are illustrated by arrows, and the tip side of the arrows is "+ (plus)". , The base end side is "-(minus)". Further, in the following, the direction parallel to the X axis is referred to as "X direction", the direction parallel to the Y axis is referred to as "Y direction", and the direction parallel to the Z axis is referred to as "Z direction". Further, in the following, for convenience of explanation, the upper + Z direction side in FIG. 1 may be referred to as “upper”, and the lower −Z direction side may be referred to as “lower”.

Further, in the following, the XY plane including the X-axis and the Y-axis is horizontal, and the Z-axis is in the vertical direction. Here, the term "horizontal" as used herein is not limited to a perfect horizontal position, and includes a state of being inclined within, for example, 5 ° with respect to the horizontal direction, as long as the transportation of electronic components is not hindered. Similarly, as used herein, the term "vertical" includes not only the case of being completely vertical, but also the case of being tilted within ± 5 ° with respect to the vertical. Also, as used herein, the term "parallel" includes not only the case where two lines (including axes) or planes are completely parallel to each other, but also the case where they are inclined within ± 10 °. Further, in the present specification, "orthogonal" includes not only the case where two lines (including axes) or planes are completely orthogonal to each other but also the case where they are inclined within ± 10 °.

1. 1. 1st Embodiment 1.1: Robot according to 1st Embodiment First, regarding the structure of the robot according to 1st Embodiment, with reference to FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, and FIG. explain. FIG. 1 is a diagram showing the overall configuration of the robot. FIG. 2 is a cross-sectional view showing a schematic configuration of a connection portion between the motor unit and the arm of the robot according to the first embodiment. FIG. 3 shows a connection configuration between the first rotating portion and the second rotating portion, and is a cross-sectional view taken along the line QQ of FIG. FIG. 4 shows an arrangement configuration of the rotating body and the metal leaf spring, and is an enlarged cross-sectional view seen from the same direction as FIG. FIG. 5 shows an arrangement configuration of the rotating body and the metal leaf spring, and is a front sectional view of FIG. FIG. 6 is a schematic view illustrating the process of reducing the external force.

As shown in FIGS. 1 and 2, the robot 2 according to the first embodiment is a horizontal articulated robot also called a SCARA robot, and is connected to a control device 3 that controls the robot 2. The application of the robot 2 is not particularly limited, and can be used, for example, in each work such as holding, transporting, assembling, and inspecting an object such as an electronic component and an electronic device.

The robot 2 has a base 21 as a first member and an arm 22 as a second member provided on the base 21 and rotatable around a first rotation shaft J1 which is a rotation axis with respect to the base 21. And a work head 25 provided on the arm 22. Further, the robot 2 includes arm drive units 26 and 27 as motor units for driving the arm 22 around the first rotation shaft J1 which is the rotation shaft and around the second rotation shaft J2 which is the rotation shaft. It has a work head drive unit 28 for driving the work head 25. Further, the robot 2 is provided at a position different from the second rotation shaft J2, is located on the work head 25 and moves in parallel with the second rotation shaft J2, and is provided with an end effector (not shown) on one lower end side. It has a spline shaft 253, which is a shaft to be formed.

Hereinafter, the configuration of the robot 2 will be described in more detail.
The base 21 is fixed to the floor surface 10 shown in FIG. 2, for example, with bolts or the like. The arm 22 is connected to the base 21 and is provided at the tip of the first arm 23 and the first arm 23 which is connected to the base 21 and can rotate around the first rotation shaft J1. It has a second arm 24 that is rotatably connected around a second rotation shaft J2 that is parallel to the first rotation shaft J1. Therefore, in this configuration, the base 21 is the first member and the first arm 23 is the second member. The first arm 23 rotatably connects the second arm 24 around the second rotation shaft J2, and when the first arm 23 is the first member, the second arm 24 is the second member. Can be.

The base 21 as the first member is an arm as a motor unit that rotates the first arm 23 as the second member with respect to the base 21 around the first rotation shaft J1 as the rotation shaft thereof. A drive unit 26 is provided. The configuration of the arm drive unit 26 will be described in detail later.

Further, in the second arm 24, an arm drive unit 27 as a motor unit for rotating the second arm 24 around the second rotation shaft J2 as the rotation shaft thereof is provided with respect to the first arm 23. Has been done. The arm drive unit 27 can have the same configuration as the arm drive unit 26 that rotates the first arm 23. The arm drive unit 27 in the second arm 24 is provided with a second motor 271 and a speed reducer (not shown). The second motor 271 is provided with a second encoder 272 as an angle sensor for detecting the amount of rotation of the second motor 271, and the rotation of the second arm 24 with respect to the first arm 23 by the output from the second encoder 272. The moving angle can be detected. In the following, the arm drive unit 26 will be described as a typical example.

The work head 25 is provided at a position different from the tip end portion of the second arm 24, that is, the second rotation shaft J2 as the rotation shaft of the second arm 24. The working head 25 has a spline nut 251 and a ball screw nut 252 coaxially arranged at the tip of the second arm 24, and a spline shaft 253 inserted through the spline nut 251 and the ball screw nut 252.

The spline shaft 253 is rotatable around the third rotation shaft J3, which is the central axis of the second arm 24, and is in the direction along the third rotation shaft J3, in other words, the third. The reciprocating movement is possible in the direction parallel to the rotation shaft J3. The first rotation shaft J1, the second rotation shaft J2, and the third rotation shaft J3 are parallel to each other and are respectively along the vertical direction.

Further, in the second arm 24, a third motor 281 that rotates the spline nut 251 to rotate the spline shaft 253 around the third rotation shaft J3 is provided. Further, the third motor 281 is provided with a third encoder 282 as an angle sensor for detecting the amount of rotation of the third motor 281, and the spline shaft 253 with respect to the second arm 24 is provided by the output from the third encoder 282. The amount of rotation can be detected. Further, in the second arm 24, a fourth motor 291 is provided which rotates the ball screw nut 252 to move the spline shaft 253 in the direction along the third rotation shaft J3. Further, the fourth motor 291 is provided with a fourth encoder 292 as an angle sensor for detecting the amount of rotation of the fourth motor 291, and the spline shaft 253 with respect to the second arm 24 is provided by the output from the fourth encoder 292. The amount of movement can be detected.

As shown in FIG. 1, a payload 254 for mounting an end effector (not shown) is provided at the tip of the spline shaft 253 on the lower end side. The end effector to be attached to the payload 254 is not particularly limited, and examples thereof include a hand holding the object and a work tool for processing the object. The holding of the object by the hand includes gripping and suction.

1.2: Arm drive unit as a motor unit The base 21 serves as a motor unit that rotates the first arm 23 with respect to the base 21 around the first rotation shaft J1 as the rotation shaft thereof. An arm drive unit 26 is provided. The arm drive unit 26 is connected to the first motor 261 and the first encoder 262 as an angle sensor for detecting the amount of rotation of the first motor 261 and the rotation shaft 263 (see FIG. 2) of the first motor 261 to reduce the speed. It has a speed reducer 30 that outputs the rotation to the output side, which is the first arm 23 side. The speed reducer 30 is rotatably held by an input side holding portion 31 connected to the base 21 via a bearing portion 32. Thereby, the deviation of the rotation center of the speed reducer 30 can be prevented.

The arm drive unit 26 can detect the rotation angle of the first arm 23 with respect to the base 21 by the output from the first encoder 262 and the output side encoder 264 described later. The first encoder 262 can be said to be the input side encoder of the first motor 261.

Further, the arm drive unit 26 rotates relative to the first rotation unit 50 along the rotation direction of the first rotation unit 50 connected to the output side of the speed reducer 30 and the first rotation unit 50. It has a second rotating unit 60 that moves, and an output side encoder 264 as an angle sensor that detects the rotation angle of the second rotating unit 60.

The first rotating unit 50 is connected to the output side of the speed reducer 30 and is opposite to the arrangement side of the speed reducer 30 with respect to the first input unit 501 that receives the rotation output from the speed reducer 30 and the first input unit 501. It has a second input unit 502 connected to the first input unit 501 on the side.

The second rotating portion 60 is located outside the first rotating portion 50, and can rotate and move relative to the first rotating portion 50 along the rotating direction of the first rotating portion 50. The first arm 23 is connected to the second rotating portion 60. That is, the first arm 23 receives the rotation of the second rotating portion 60 and rotates around the first rotation shaft J1 with respect to the base 21. The second rotating unit 60 is located at a position facing the first output unit 601 of the first rotating unit 50 and the second input unit 502 of the first rotating unit 50. It has a second output unit 602 that is arranged.

The second rotating portion 60 is connected to the first rotating portion 50 via a plurality of rotating bodies 41 arranged between the first rotating portion 50 and the first input portion 501, and a metal leaf spring 42 as an elastic body. Is connected to. The plurality of rotating bodies 41 and the metal leaf springs 42 are arranged between the outer peripheral portion of the first input portion 501 of the first rotating portion 50 and the inner peripheral portion of the first output portion 601 of the second rotating portion 60. Has been done. Further, the metal leaf spring 42 is arranged between the plurality of rotating bodies 41 and the first output unit 601 of the second rotating unit 60, and is configured to apply pressurization to the rotating body 41. There is.

The plurality of rotating bodies 41 have a cylindrical shape, and as shown in FIGS. 3, 4, and 5, the central axis of the cylindrical shape is formed along the rotation axes of the first rotating portion 50 and the second rotating portion 60. It is held by a concave holding portion 511 having a bottom portion 512 dug from the outer peripheral surface of the first input portion 501 of the first rotating portion 50 so as to be arranged. The rotating body 41 is held so as to be rotatable and slidable with respect to the holding portion 511 when an external force of a magnitude that deforms the metal leaf spring 42 is applied to the first output portion 601 side. That is, the rotating body 41 does not rotate when it receives the rotational force of the first input unit 501, and when the first output unit 601 rotates, it is held by the rotation of the first output unit 601. It can roll and rotate along the portion 511. In this way, the rotating body 41 rotates and slides in the concave holding portion 511, so that external force such as an impact can be dispersed. The rotating body 41 can be formed of an iron-based alloy such as iron or stainless steel, a metal such as a copper alloy, or a hard resin.

In addition, 18 rotating bodies 41 in this embodiment are arranged and are held by 18 holding parts 511 provided at substantially equal intervals on the outer circumference of the first input part 501. The number of arrangements of the rotating bodies 41 may be plural, and is not limited to 18. Further, it does not necessarily have to be provided at equal intervals.

It is preferable that the digging corner portion of the holding portion 511 in the first input portion 501 is provided with a so-called arc-shaped chamfer 511r. By applying such chamfering 511r, it is possible to reduce the rotational resistance due to the corners and facilitate the rolling rotation of the rotating body 41.

As shown in FIGS. 3, 4, and 5, the metal leaf spring 42 faces each of the arrangement positions of the plurality of rotating bodies 41, and a plurality of bent portions 422 that come into contact with the rotating body 41 while applying pressurization. It is composed of, for example, a strip-shaped spring member having the above. The metal leaf spring 42 is bent back in a wavy shape from the base material portion 421 arranged in a cylindrical shape along the outer circumference of the first input portion 501 of the first rotating portion 50 and from the base material portion 421 to the top 423. It has a bent portion 422 that holds the rotating body 41. The metal leaf spring 42 having such a configuration can reliably hold the rotating body 41 by the bent portion 422 curved from the base material portion 421. As the spring member constituting the metal leaf spring 42, a cold-rolled steel plate for springs, a stainless steel plate for springs, a copper alloy plate such as phosphorus bronze or beryllium copper, or the like can be used.

In the metal leaf spring 42, the top portion 423 of the bent portion 422 is inserted into the groove portion 612 provided in the inner peripheral wall portion 611 of the first output portion 601 of the second rotating portion 60, and one side is positioned along the inner bottom portion 613. Arranged to do. Then, the metal leaf spring 42 is pressed against the respective wall surfaces of the bent portion 422 with the top portion 423 inserted into the groove portion 612 as a base point, and the rotating body 41 comes into contact with the first input portion 501 and the first output. It is held between the unit and the unit 601. In other words, by such a metal leaf spring 42, the rotating body 41 is pressed and held by the holding portion 511 of the first input portion 501 by each wall surface of the bent portion 422 folded back at the top portion 423.

By forming the elastic member with the metal leaf spring 42 in this way, the weight of the arm drive unit 26 can be reduced, and the weight of the robot 2 can be reduced. Further, in such a metal leaf spring 42, the rotating body 41 can be reliably held by the bent portion 422 curved from the base material portion 421, and when the metal leaf spring 42 transmits the rotational force and receives an external force. Can be reliably deformed.

As described above, the arm drive unit 26 of the present embodiment has a rotating body 41 and an elastic body between the first rotating unit 50 on the rotation input side and the second rotating unit 60 on the output side of the first motor 261. The structure is such that the metal leaf spring 42 is interposed. By using the arm drive unit 26 having such a configuration, the robot 2 rotates when the arm 22 receives an external force such as an impact, which is arranged between the first rotation unit 50 and the second rotation unit 60. Due to the rolling of the body 41 and the bending of the metal leaf spring 42 with which the rotating body 41 comes into contact, the time until the external force is completely received can be lengthened. That is, since the robot 2 can release the external force when the arm 22 receives an impact or the like by using the arm driving unit 26, the rotating shaft side of the first motor 261, for example, the speed reducer 30 or the rotating shaft 263. Alternatively, it is possible to reduce an external force such as an impact received by the first motor 261 or the like. As a result, it is possible to suppress damage to the arm drive unit 26 when the arm 22 receives an external force such as an impact.

The impact reducing effect will be described in more detail with reference to FIG.
The momentum mv shown in the following equation (1) is applied to the arm 22 as an external force. In such a case, the second rotating portion 60 and the metal leaf spring 42 connected to the arm 22 rotate and move in the direction of the arrow R, for example, as shown in FIG.

Due to the rotational movement of the second rotating portion 60 and the metal leaf spring 42, the rotating body 41 that is in contact with the metal leaf spring 42 and is pressurized is rotated in the rotational direction while rotating so as to slide in the holding portion 511. The bent portion 422 of the positioned metal leaf spring 42 is pressed, and the metal leaf spring 42 is deformed during the distance D to, for example, the position of the deformed metal leaf spring 42f. As the rotating body 41 rotates in this way, the moving distance in which the second rotating portion 60 rotates and moves with respect to the first rotating portion 50 becomes apparently longer. As a result, the time Δt until the momentum mv is completely received can be lengthened, so that the “F” of the following equation (2), that is, the external force F transmitted to the first rotating portion 50 side can be reduced.

The metal leaf spring 42 and the rotating body 41 are arranged with the base material portion 421 of the metal leaf spring 42 and the outer peripheral surface of the first input portion 501 of the first rotating portion 50 facing the metal leaf spring 42. It is preferable that the distance L1 between the two is shorter than the protrusion distance L2 of the rotating body 41 from the outer peripheral surface of the first input unit 501 of the first rotating unit 50.

By arranging the metal leaf spring 42 and the rotating body 41 in this way, the rotating body 41 is placed between the base material portion 421 of the metal leaf spring 42 and the outer peripheral surface of the first input portion 501 of the first rotating portion 50. It becomes impossible to get out of the metal leaf spring 42, and the positional relationship between the metal leaf spring 42 and the rotating body 41 can be reliably maintained.

Further, as described above, the metal leaf spring 42 may be configured by providing a plurality of bent portions 422 on one plate-shaped base material and bending one plate-shaped base material in a circular shape. , Individual pieces in which the bent portion 422 is provided on the individual base material may be prepared and arranged corresponding to each rotating body 41.

The output side encoder 264 as an angle sensor can detect the rotation angle of the second rotation unit 60. In other words, the output side encoder 264 can measure the rotation position of the second rotation unit 60. The control device 3 compares the rotation angle detected by the output side encoder 264 with the rotation angle detected by the first encoder 262, and compares the rotation angle of the second rotation unit 60 due to, for example, the deformation hysteresis of the metal leaf spring 42. Calculate the rotation error. The control device 3 can detect the rotation angle of the first arm 23 connected to the second rotation unit 60 with respect to the base 21 by reflecting this rotation error.

Further, a rotating bearing 503 as a rotating bearing unit is provided between the second output unit 602 of the second rotating unit 60 and the second input unit 502 of the first rotating unit 50. The second rotating portion 60 is connected via a rotating bearing 503 so as to be rotatable relative to the first rotating portion 50. In this way, the first rotating portion 50 and the second rotating portion 60 are connected to each other via the rotating bearing 503, so that the first rotating portion 50 and the second rotating portion 60 are provided between the first input unit 501 and the first output unit 601. It is possible to reduce the deviation of the rotation center between the input side and the output side of the rotation of the arm drive unit 26 due to the deformation of the metal leaf spring 42, that is, the eccentricity of the so-called rotation center.

The robot 2 according to the first embodiment described above rotates when the rotating body 41 arranged between the first rotating portion 50 and the second rotating portion 60 receives an external force F such as an impact on the arm 22. , And the bending of the metal leaf spring 42 as an elastic body can increase the time Δt until the external force F is completely received. That is, since the robot 2 can release the external force F by the rotation of the rotating body 41 and the bending of the metal leaf spring 42 as the elastic body, the rotating shaft 263 of the first motor 261 in the arm driving unit 26 as the motor unit It is possible to reduce the external force F such as the impact received on the side. As a result, it is possible to suppress damage to the arm drive unit 26 when the arm 22 receives an external force F such as an impact.

2. 2. 2nd Embodiment 2.1: Robot according to 2nd Embodiment First, the configuration of the robot according to 2nd Embodiment will be described with reference to FIGS. 7, 8 and 9. FIG. 7 is a cross-sectional view showing a schematic configuration of a connection portion between the motor unit and the arm of the robot according to the second embodiment. FIG. 8 shows an arrangement configuration of the rotating body and the metal leaf spring, and is an enlarged cross-sectional view at the same position as in FIG. FIG. 9 shows an arrangement configuration of the rotating body and the metal leaf spring, and is a front sectional view of FIG.

The robot 2A according to the second embodiment shown in FIG. 7 has a different configuration of the arm drive unit 26a as a motor unit from the robot 2 of the first embodiment described above. Specifically, the arm drive unit 26a of the second embodiment has an outer portion at the connection position to the output side of the speed reducer 30, which was an inner portion in the first embodiment, and is an outer portion in the first embodiment. The configuration is such that the connection position to the first arm 23 is the inner portion. Hereinafter, the configuration of the arm drive unit 26a will be mainly described, and the same configurations as those in the first embodiment are designated by the same reference numerals to simplify the description or omit the description thereof.

The robot 2A according to the second embodiment is a horizontal articulated robot also called a SCARA robot. The application of the robot 2A is not particularly limited, and can be used, for example, in each work such as holding, transporting, assembling, and inspecting an object such as an electronic component and an electronic device.

The basic configuration of the robot 2A is the same as that of the first embodiment described with reference to FIG. 1, with a base 21 as a first member and a rotation axis provided on the base 21 with respect to the base 21. It has an arm 22 as a second member that can rotate around a first rotation shaft J1 and a work head 25 provided on the arm 22. Further, as shown in FIG. 1, the robot 2A is an arm as a motor unit that drives the arm 22 around the first rotation shaft J1 which is a rotation shaft and around the second rotation shaft J2 which is a rotation shaft. It has a drive unit 26 and a work head drive unit 28 that drives the work head 25. Further, the robot 2A is provided at a position different from the second rotation shaft J2, is located on the work head 25 and moves in parallel with the second rotation shaft J2, and an end effector (not shown) is provided on one lower end side. It has a spline shaft 253, which is a shaft to be formed.

The base 21 is fixed to the floor surface 10 shown in FIG. 7, for example, with bolts or the like. The arm 22 is connected to the base 21 and has a first arm 23 that can rotate around the first rotation shaft J1 with respect to the base 21. A second arm 24 and the like are provided at the tip of the first arm 23 as in the first embodiment, but the description thereof will be omitted.

2.2: Arm drive unit as a motor unit The base 21 serves as a motor unit that rotates the first arm 23 with respect to the base 21 around the first rotation shaft J1 as the rotation shaft thereof. An arm drive unit 26a is provided. The arm drive unit 26a is connected to the first motor 261 and the first encoder 262 as an angle sensor for detecting the amount of rotation of the first motor 261 and the rotation shaft 263 of the first motor 261 to perform decelerated rotation. It has a speed reducer 30a that outputs to the output side, which is the arm 23 side. The speed reducer 30a is rotatably held by an input side holding portion 31 connected to the base 21 via a bearing portion 32. Thereby, the deviation of the rotation center of the speed reducer 30a can be prevented.

The arm drive unit 26a can detect the rotation angle of the first arm 23 with respect to the base 21 by the output from the first encoder 262 and the output side encoder 264a described later. The first encoder 262 can be said to be the input side encoder of the first motor 261.

Further, the arm drive unit 26a rotates relative to the first rotation unit 60a along the rotation direction of the first rotation unit 60a connected to the output side of the speed reducer 30a and the first rotation unit 60a. It has a second rotating portion 50a that moves, and an output side encoder 264a as an angle sensor that detects the rotation angle of the second rotating portion 50a.

The first rotating unit 60a is connected to the output side of the speed reducer 30a and is opposite to the arrangement side of the speed reducer 30a with respect to the first input unit 601a that receives the rotation output from the speed reducer 30a and the first input unit 601a. It has a second input unit 602a connected to the first input unit 601a on the side.

The second rotating portion 50a is located inside the first rotating portion 60a, and can rotate and move relative to the first rotating portion 60a along the rotation direction of the first rotating portion 60a. The first arm 23 is connected to the second rotating portion 50a. That is, the first arm 23 receives the rotation of the second rotating portion 50a and rotates around the first rotating shaft J1 with respect to the base 21. The second rotating unit 50a is located at a position facing the first output unit 501a of the first rotating unit 60a and facing the first input unit 601a, and at a position facing the second input unit 602a of the first rotating unit 60a. It has a second output unit 502a that is arranged.

The second rotating portion 50a is provided with the first rotating portion 60a via a plurality of rotating bodies 41a arranged between the first rotating portion 60a and the first input portion 601a and a metal leaf spring 42a as an elastic body. Is connected to. The plurality of rotating bodies 41a and the metal leaf spring 42a are arranged between the inner peripheral portion of the first input portion 601a of the first rotating portion 60a and the outer peripheral portion of the first output portion 501a of the second rotating portion 50a. Has been done. Further, the metal leaf spring 42a is arranged between the plurality of rotating bodies 41a and the first output unit 501a of the second rotating part 50a, and is configured to apply pressurization to the rotating body 41a. There is.

The plurality of rotating bodies 41a have a cylindrical shape as in the first embodiment, and as shown in FIGS. 8 and 9, the plurality of rotating bodies 41a are cylindrical along the rotation axes of the first rotating portion 60a and the second rotating portion 50a. It is held by a concave holding portion 511a having a bottom portion 512a dug into the outer peripheral surface of the first output portion 501a of the second rotating portion 50a so that the central axis of the shape is arranged. The rotating body 41a is rotatably and slidably held with respect to the holding portion 511a when an external force of a magnitude that deforms the metal leaf spring 42a is applied to the first output portion 501a side. That is, the rotating body 41a does not rotate when it receives the rotational force of the first input unit 601a, and when the first output unit 501a rotates, it is held as the first output unit 501a rotates. It can roll and rotate along the portion 511a. In this way, the rotating body 41a rotates and slides in the concave holding portion 511a, so that external force such as an impact can be dispersed. The material constituting the rotating body 41a can be formed of, for example, an iron-based alloy such as iron or stainless steel, a metal such as a copper alloy, or a hard resin.

Although not shown, 18 rotating bodies 41a in the present embodiment are arranged as in the first embodiment, and are held by 18 holding portions 511a provided at substantially equal intervals on the outer circumference of the first output unit 501a. ing. The number of arrangements of the rotating bodies 41a may be plural, and is not limited to 18. Further, it does not necessarily have to be provided at equal intervals.

It is preferable that the digging corner portion of the holding portion 511a in the first output portion 501a is provided with a so-called arc-shaped chamfer 511r. By applying such chamfering 511r, it is possible to reduce the rotational resistance due to the corners and facilitate the rolling rotation of the rotating body 41a.

Similar to the first embodiment, the metal leaf spring 42a has a corrugated shape, and as shown in FIGS. 8 and 9, the metal leaf spring 42a faces each of the arrangement positions of the plurality of rotating bodies 41a while applying pressurization. It is composed of, for example, a strip-shaped spring member having a plurality of bent portions 422a that come into contact with the rotating body 41a. The metal leaf spring 42a is bent back in a wavy shape from the base material portion 421a, which is arranged in a cylindrical shape along the outer circumference of the first output portion 501a of the second rotating portion 50a, at the top portion 423a. It has a bent portion 422a that holds the rotating body 41a. The metal leaf spring 42a having such a configuration can reliably hold the rotating body 41a by the bent portion 422a curved from the base material portion 421a. As the spring member constituting the metal leaf spring 42a, for example, a cold-rolled steel plate for a spring, a stainless steel plate for a spring, a copper alloy plate such as phosphorus bronze or beryllium copper can be used.

In the metal leaf spring 42a, the top portion 423a of the bent portion 422a is inserted into the groove portion 612a provided in the inner peripheral wall portion 611a of the first input portion 601a of the first rotating portion 60a, and one side is positioned along the inner bottom portion 613a. Arranged to do. Then, the metal leaf spring 42a is pressed against the respective wall surfaces of the bent portion 422a with the top portion 423a inserted into the groove portion 612a as a base point, and the rotating body 41a comes into contact with the first input portion 601a and the first output. It is held between the parts 501a. In other words, by such a metal leaf spring 42a, the rotating body 41a is pressed and held by the holding portion 511a of the first output portion 501a by the respective wall surfaces of the bent portion 422a folded back at the top portion 423a.

By forming the elastic member from the metal leaf spring 42a in this way, the weight of the arm drive unit 26a can be reduced, and the weight of the robot 2A can be reduced. Further, such a metal leaf spring 42a can surely hold the rotating body 41a by the bent portion 422a curved from the base material portion 421a, and when the metal leaf spring 42a transmits the rotational force and receives an external force. Can be reliably deformed.

As described above, the arm drive unit 26a of the present embodiment has a rotating body 41a and an elastic body between the first rotating portion 60a on the rotation input side and the second rotating portion 50a on the output side of the first motor 261. The structure is such that a metal leaf spring 42a is interposed. By using the arm drive unit 26a having such a configuration, the robot 2A rotates when the arm 22 receives an external force such as an impact, which is arranged between the first rotation unit 60a and the second rotation unit 50a. Due to the rolling of the body 41a and the bending of the metal leaf spring 42a with which the rotating body 41a abuts, the time until the external force is completely received can be lengthened. That is, since the robot 2A can release the external force when the arm 22 receives an impact or the like by using the arm drive unit 26a, the rotation shaft side of the first motor 261, for example, the speed reducer 30a or the rotation shaft 263. Alternatively, it is possible to reduce an external force such as an impact received by the first motor 261 or the like. As a result, it is possible to suppress damage to the arm drive unit 26a when the arm 22 receives an external force such as an impact. Since the impact reducing action is the same as that of the first embodiment described above, the description thereof is omitted here.

The arrangement of the metal leaf spring 42a and the rotating body 41a is the same as in the first embodiment, with the base material portion 421a of the metal leaf spring 42a and the metal leaf spring 42a of the first output portion 501a of the second rotating portion 50a. It is preferable that the distance L1 from the outer peripheral surface, which is the opposite surface, is shorter than the protrusion distance L2 of the rotating body 41a from the outer peripheral surface of the first output portion 501a of the second rotating portion 50a.

By arranging the metal leaf spring 42a and the rotating body 41a in this way, the rotating body 41a is located between the base material portion 421a of the metal leaf spring 42a and the outer peripheral surface of the first output portion 501a of the second rotating portion 50a. It becomes impossible to escape from the metal leaf spring 42a, and the positional relationship between the metal leaf spring 42a and the rotating body 41a can be reliably maintained.

Further, the metal leaf spring 42a may be configured by providing a plurality of bent portions 422a on one plate-shaped base material and bending one plate-shaped base material in a circular shape as described above. , Individual pieces in which the bent portion 422a is provided on the individual base material may be prepared and arranged corresponding to the respective rotating bodies 41a.

The output side encoder 264a as an angle sensor can detect the rotation angle of the second rotation unit 50a. The control device (not shown) of the robot 2A compares the rotation angle detected by the output side encoder 264a with the rotation angle detected by the first encoder 262, and compares, for example, the resilience of the metal leaf spring 42a, so-called deformation hysteresis. The rotation error of the second rotating portion 50a due to the above is calculated. The control device (not shown) of the robot 2A can reflect the rotation error and detect the rotation angle of the first arm 23 connected to the second rotation unit 50a with respect to the base 21.

Further, a rotating bearing 503 is provided between the second output unit 502a of the second rotating unit 50a and the second input unit 602a of the first rotating unit 60a. The second rotating portion 50a is connected via a rotating bearing 503 so as to be rotatable relative to the first rotating portion 60a. In this way, the first rotating portion 60a and the second rotating portion 50a are connected to each other via the rotating bearing 503, so that the first rotating portion 60a and the second rotating portion 50a are provided between the first input unit 601a and the first output unit 501a. It is possible to reduce the deviation of the rotation center between the input side and the output side of the rotation of the arm drive unit 26a due to the deformation of the metal leaf spring 42a, that is, the so-called eccentricity of the rotation center.

Similar to the first embodiment, the robot 2A according to the second embodiment described above is arranged between the first rotating portion 60a and the second rotating portion 50a when the arm 22 receives an external force F such as an impact. Due to the rotation of the rotating body 41a and the bending of the metal leaf spring 42a as an elastic body, the time until the external force is finished can be lengthened, that is, the external force can be released, so that the arm as a motor unit can be released. It is possible to reduce the external force F such as the impact received on the rotation shaft 263 side of the first motor 261 in the drive unit 26a. As a result, it is possible to suppress damage to the arm drive unit 26a when the arm 22 receives an external force such as an impact.

In the above description of the first embodiment and the second embodiment, the first arm 23 as the second member is attached to the base 21 as the first member, and the first rotation shaft as the rotation shaft thereof. Although the arm drive unit 26a as a motor unit that rotates around J1 has been described as an example, this configuration includes a second arm 24 as a second member with respect to a first arm 23 as a first member. It can also be applied to the arm drive unit 27 as a motor unit that rotates around the second rotation shaft J2 as the rotation shaft.

3. 3. Deformation example relating to the arrangement of the rotating body and the metal leaf spring Next, a modification relating to the arrangement of the rotating body and the metal leaf spring will be described with reference to FIG. FIG. 10 shows a modified example of the arrangement configuration of the rotating body and the metal leaf spring, and is an enlarged cross-sectional view similar to that of FIG.

In the first and second embodiments described above, regarding the arrangement of the rotating bodies 41, 41a and the metal leaf springs 42, 42a, the rotating bodies 41, 41a are arranged inside, and the metal plate is arranged outside the rotating bodies 41, 41a. A configuration example in which the springs 42 and 42a are arranged has been described. In this modification, as shown in FIG. 10, the rotating body 41b and the metal leaf spring 42b are arranged at positions opposite to those described above. In the present modification shown in FIG. 10, the arrangement configuration of the rotating body 41b and the metal leaf spring 42b will be described based on the configuration of the first embodiment.

The plurality of rotating bodies 41b have a cylindrical shape, and the first output of the second rotating portion 60b is arranged so that the central axis of the cylindrical shape is arranged along the rotating axes of the first rotating portion 50b and the second rotating portion 60b. It is held by a concave holding portion 622 dug into the inner peripheral surface of the portion 601b. The rotating body 41b is rotatably and slidably held with respect to the holding portion 622 when an external force of a magnitude that deforms the metal leaf spring 42b is applied to the first output portion 601b side. That is, the rotating body 41b does not rotate when it receives the rotational force of the first input unit 501b, and when the first output unit 601b rotates, the rotating body 41b accompanies the rotation of the first output unit 601b. It can roll and rotate along the holding portion 622. In this way, the rotating body 41b rotates and slides in the concave holding portion 622, so that external force such as an impact can be dispersed. The rotating body 41b can be formed of an iron-based alloy such as iron or stainless steel, a metal such as a copper alloy, or a hard resin.

The metal leaf spring 42b is composed of, for example, a strip-shaped spring member having a plurality of bent portions 422b facing each of the arrangement positions of the plurality of rotating bodies 41b and abutting against the rotating body 41b while applying pressurization. .. The metal leaf spring 42b is bent back in a wavy shape from the base material portion 421b, which is arranged cylindrically along the inner circumference of the first output portion 601b of the second rotating portion 60b, at the top portion 423b. It has a bent portion 422b that holds the rotating body 41b. The metal leaf spring 42b having such a configuration can reliably hold the rotating body 41b by the bent portion 422b curved from the base material portion 421b. As the spring member constituting the metal leaf spring 42b, a cold-rolled steel plate for springs, a stainless steel plate for springs, a copper alloy plate such as phosphorus bronze or beryllium copper, or the like can be used.

The metal leaf spring 42b is arranged by inserting the top portion 423b of the bent portion 422b into the groove portion 522 provided in the outer peripheral wall portion 523 of the first input portion 501b of the first rotating portion 50b. Then, the metal leaf spring 42b is pressed against the respective wall surfaces of the bent portion 422b with the top portion 423b inserted into the groove portion 522 as a base point, and the rotating body 41b comes into contact with the first input portion 501b and the first output. It is held between the parts and the parts 601b. In other words, by such a metal leaf spring 42b, the rotating body 41b is pressed and held by the holding portion 622 of the first output portion 601 by the respective wall surfaces of the bent portion 422b folded back at the top portion 423b.

By forming the elastic member with the metal leaf spring 42b in this way, the weight of the arm drive unit 26 can be reduced, and the weight of the robot 2 (see FIG. 1) can be reduced. Further, such a metal leaf spring 42b can reliably hold the rotating body 41b by the bent portion 422b curved from the base material portion 421b, and when the metal leaf spring 42b transmits the rotational force and receives an external force. Can be reliably deformed.

Even in the arrangement of the rotating body 41b and the metal leaf spring 42b according to such a modification, the same effect as that of the first embodiment and the second embodiment described above can be obtained. That is, when the arm 22 (see FIG. 2) receives an external force such as an impact, the rotating body 41b arranged between the first input unit 501b and the first output unit 601b rolls and the rotating body 41b hits the ground. Due to the bending of the metal leaf spring 42b in contact with the metal leaf spring 42b, the time until the external force is completely received can be lengthened. That is, since the robot 2 (see FIG. 2) can release an external force when the arm 22 receives an impact or the like, for example, the speed reducer 30, the rotary shaft 263, the first motor 261 and the like shown in FIG. It is possible to reduce the external force such as the impact received. As a result, it is possible to suppress damage to the speed reducer 30, the rotating shaft 263, the first motor 261 and the like when the arm 22 receives an external force such as an impact.

In the above-described embodiment and modification, the cylindrical rotating bodies 41, 41a, and 41b have been described as examples, but the shape is not limited to the cylindrical shape as long as it has a rolling shape. As another rotating body having such characteristics, for example, a sphere, a football ball-like cylinder, or the like can be applied.

Further, in the above-described embodiment and modified example, metal leaf springs 423, 423a, 423b are exemplified as elastic bodies arranged between the rotating bodies 41, 41a, 41b and the second rotating portions 60, 50a, 60b. However, it is not limited to this. As the elastic body instead of the metal leaf springs 42, 42a, 42b, for example, a resin leaf spring, an elastic structure made of natural rubber, synthetic rubber, elastic resin, or the like can be applied.

Further, the inner wall surface of the holding portions 511,511a, 622 reduces the contact resistance by reducing the contact area between the holding portions 511,511a, 622 and the rotating bodies 41, 41a, 41b, thereby reducing the contact resistance of the rotating bodies 41, 41a. , 41b can be easily rotated. For this reason, the inner wall surface of the holding portions 511, 511a, 622 may be provided with recesses dug into, for example, a single or a plurality of strip shapes or a plurality of point shapes.

Further, in the first embodiment and the second embodiment described above, as the configuration of the robots 2 and 2A, the control device 3 is provided outside the robots 2 and 2A, but the present invention is not limited to this. The control device 3 may be provided outside the robots 2 and 2A, or may be provided inside.

Further, in the first embodiment and the second embodiment described above, the robots 2 and 2A have been described by exemplifying a horizontal articulated robot also called a SCARA robot, but the present invention is not limited to this. The robot to which the configuration of the present application can be applied may be a robot having a rotatable arm portion, and for example, a 6-axis control robot, a dual-arm robot, or the like can be raised.

The contents derived from the above-described embodiments will be described below as each aspect.

[Aspect 1] The robot according to this aspect includes a first member, a second member that rotates about a rotation axis with respect to the first member, and a motor unit that rotates the second member. The motor unit rotates along the rotation direction of the motor having a rotation shaft, the first rotation portion connected to the rotation shaft, and the first rotation portion, and is connected to the second member. The second rotating part, a plurality of rotating bodies arranged between the first rotating part and the second rotating part, and between the rotating body and the first rotating part, or between the rotating body and the first rotating part. It has an elastic body arranged between the two rotating portions.

According to this aspect, when an external force such as an impact is applied to the second member, the external force is completely received by the bending of the rotating body and the elastic body arranged between the first rotating portion and the second rotating portion. Since the time can be lengthened, that is, the external force can be released, the external force such as the impact received on the rotating shaft side of the motor in the motor unit can be reduced. As a result, it is possible to suppress damage to the motor unit when the second member receives an external force such as an impact.

[Aspect 2] In the robot according to the above aspect, a rotating bearing portion may be provided between the first rotating portion and the second rotating portion at a position different from the arrangement position of the rotating body. Good.

According to this aspect, the eccentricity of the rotation center of the motor unit due to the deformation of the elastic body can be reduced by the rotating bearing portion provided between the first rotating portion and the second rotating portion.

[Aspect 3] The robot according to the above aspect may be provided with an angle sensor for measuring the rotation position of the second rotating portion.

According to this aspect, the angle sensor that measures the rotation position of the second rotating portion may be caused by the low rigidity of the elastic body provided between the first rotating portion and the second rotating portion. It is possible to reduce the angle error between the rotation angle of the rotation shaft of the motor and the rotation angle of the second member.

[Aspect 4] In the robot according to the above aspect, the first rotating portion or the second rotating portion may be provided with a concave holding portion for holding the rotating body so as to be rotatable and slidable. Good.

According to this aspect, the rotating body rotates and slides in the concave holding portion, so that an external force such as an impact can be dispersed.

[Aspect 5] In the robot according to the above aspect, the elastic body may be made of a metal leaf spring.

According to this aspect, the weight of the motor unit can be reduced and the weight of the robot can be reduced by forming the elastic body with a metal leaf spring.

[Aspect 6] In the robot according to the above aspect, the metal leaf spring has a base material portion along the first rotating portion and a bent portion curved from the base material portion to hold the rotating body. You may have it.

According to this aspect, the rotating body can be reliably held by the bent portion curved from the base material portion, the rotational force can be transmitted by the metal leaf spring, and the deformation when an external force is received can be easily generated. ..

[Aspect 7] In the robot according to the above aspect, the first rotating portion or the second rotating portion may be provided with a groove for inserting the top of the bent portion of the metal leaf spring. ..

According to this aspect, since the top of the bent portion of the metal leaf spring is held by the groove portion, the rotational force of the metal leaf spring can be reliably transmitted to the first rotating portion or the second rotating portion.

[Aspect 8] In the robot according to the above aspect, the distance between the base material portion of the metal leaf spring and the surface of the first rotating portion or the second rotating portion facing the metal leaf spring is determined. It may be shorter than the protrusion distance of the rotating body from the first rotating portion or the second rotating portion.

According to this aspect, it is possible to prevent the rotating body from coming out from between the base material portion of the metal leaf spring and the surface of the first rotating portion or the second rotating portion facing the metal leaf spring. , The positional relationship between the metal leaf spring and the rotating body can be reliably maintained.

2,2A ... robot, 3 ... control device, 21 ... base as first member, 22 ... arm as second member, 23 ... first arm, 24 ... second arm, 25 ... work head, 26 ... arm Drive unit, 28 ... Work head drive unit, 30, 30a ... Reducer, 31 ... Input side holding unit, 32 ... Bearing unit, 41 ... Rotating body, 42 ... Metal leaf spring as elastic body, 50 ... First rotating unit , 60 ... 2nd rotating part, 251 ... spline nut, 252 ... ball screw nut, 253 ... spline shaft, 254 ... payload, 261 ... 1st motor, 262 ... 1st encoder, 263 ... rotating shaft, 264 ... as angle sensor Output side encoder, 271 ... 2nd motor, 272 ... 2nd encoder, 281 ... 3rd motor, 282 ... 3rd encoder, 291 ... 4th motor, 292 ... 4th encoder, 421 ... Base material part, 422 ... Bending part 423 ... top, 501 ... first input, 502 ... second input, 503 ... rotating bearing, 511 ... holding, 511r ... chamfered, 512 ... bottom, 601 ... first output, 602 ... second output Part, 611 ... Inner peripheral wall part, 612 ... Groove part, 613 ... Inner bottom part, J1 ... First rotation shaft, J2 ... Second rotation shaft, J3 ... Third rotation shaft, L1 ... Distance, L2 ... Protrusion distance.

Claims (8)

With the first member
A second member that rotates around a rotation axis with respect to the first member,
A motor unit for rotating the second member is provided.
The motor unit is
A motor with a rotating shaft and
The first rotating part connected to the rotating shaft and
A second rotating portion that rotates along the rotation direction of the first rotating portion and is connected to the second member.
A plurality of rotating bodies arranged between the first rotating portion and the second rotating portion, and
A robot having an elastic body arranged between the rotating body and the first rotating portion, or between the rotating body and the second rotating portion. A rotating bearing portion is provided between the first rotating portion and the second rotating portion at a position different from the arrangement position of the rotating body.
The robot according to claim 1. An angle sensor for measuring the rotation position of the second rotating portion is provided.
The robot according to claim 1 or 2. In the first rotating part or the second rotating part,
A concave holding portion for holding the rotating body so as to be rotatable and slidable is provided.
The robot according to any one of claims 1 to 3. The elastic body is composed of a metal leaf spring.
The robot according to any one of claims 1 to 4. The metal leaf spring
The base material portion along the first rotating portion and
It has a bent portion that is curved from the base material portion and holds the rotating body.
The robot according to claim 5. In the first rotating part or the second rotating part,
A groove for inserting the top of the bent portion of the metal leaf spring is provided.
The robot according to claim 6. The distance between the base material portion of the metal leaf spring and the surface of the first rotating portion or the second rotating portion facing the metal leaf spring is
It is shorter than the protrusion distance of the rotating body from the first rotating portion or the second rotating portion.
The robot according to claim 6 or 7.

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