Drive device and robot provided with drive device

Abstract

A drive device includes a motor unit including a motor, and an amplifier that supplies a current to the motor. The amplifier includes a plurality of electrical components fixed to a substrate. The amplifier is coaxially fixed to an end portion of the motor unit in a direction of a rotating shaft of the motor. The amplifier is formed so as to be detachable from the motor unit by the operation of an operator.

Description

Technical Field

[0001] The present invention relates to a driving device and a robot having the driving device. Background Art

[0002] It has long been known that there is a drive device that supplies the rotational force of an electric motor to other components. The drive device can include an electric motor, a reducer that amplifies the rotational force of the electric motor, and a brake, etc. The electric motor of the drive device is supplied with an electric current generated based on a predetermined instruction. The electric current supplied to the electric motor is generated by an amplifier. For example, the amplifier is arranged inside a control device separated from the drive device. The control device can supply the electric current to the electric motor of the drive device with a cable. Alternatively, it is known that there is a drive device that has an amplifier in addition to a motor and a reducer (for example, Japanese Patent Gazette No. 2010-41747).

[0003] The driving device can be configured in the robot device. The robot device can have a robot having a joint portion with a direction-changing component such as an arm. The robot device can perform operations while changing the position and posture of a working tool by driving the components of the robot. In the case where the robot has a joint portion, a driving device for moving the component is configured at the joint portion. The driving device can be configured at each joint of each joint portion (for example, Japanese Patent Publication No. 2019-84607).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-41747

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-84607 Summary of the invention

[0008] Problems to be solved by the invention

[0009] The drive device can be configured in any machine. Furthermore, an amplifier can be configured in each motor of each motor. Here, compared with the reducer, the motor, and the brake, the amplifier has a higher frequency of failure. The drive device is preferably configured so that the amplifier can be easily replaced when the amplifier fails. In other words, it is preferably configured so that the amplifier can be easily removed from the drive device. However, in the existing drive device, it is difficult to remove only the amplifier from the drive device fixed to the machine.

[0010] For example, sometimes in a driving device, in addition to a primary encoder for detecting the rotational position of the motor, a secondary encoder for detecting the rotational position of the output shaft of the reducer is also configured. The secondary encoder is connected to a component related to the output of the reducer. For example, the secondary encoder is configured at the endmost position of the driving device in such a way as to detect the rotational position of a component that rotates together with the output shaft of the reducer. In contrast, the amplifier is configured inside the driving device. In order to remove the amplifier, it is necessary to disassemble the driving device after removing the entire driving device from the machine. In this way, there is a problem that only the amplifier cannot be removed from the driving device fixed to the machine.

[0011] Solutions to Solve Problems

[0012] The drive device of the disclosed method comprises: a motor unit including a motor; and a motor control unit that supplies current to the motor. The motor unit includes at least one of a reducer, a brake, and a rotation position detector. The motor control unit includes a substrate and a plurality of electrical components fixed to the substrate. The motor control unit is coaxially fixed to the end of the motor unit in the direction of the rotation axis of the motor. The motor control unit is formed to be removable from the motor unit by an operator's operation.

[0013] A robot according to an aspect of the present disclosure includes: the above-mentioned drive device; and a joint portion that rotates another component relative to one component of the robot. The drive device is disposed at the joint portion.

[0014] The effects of the invention are as follows.

[0015] According to the aspect of the present disclosure, it is possible to provide a drive device in which a motor control unit can be easily removed from the drive device, and a robot including the drive device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a perspective view of a robot in the embodiment.

[0017] Figure 2 It is a schematic cross-sectional view of the driving device in the embodiment.

[0018] Figure 3 is a circuit diagram of an amplifier in an embodiment.

[0019] Figure 4 It is a simplified three-dimensional diagram of the amplifier.

[0020] Figure 5 is a simplified top view of the amplifier.

[0021] Figure 6 This is an enlarged schematic cross-sectional view of a joint portion of a robot equipped with a drive device.

[0022] Figure 7 It is an enlarged schematic cross-sectional view of a joint portion of a driving device including an amplifier according to a comparative example. DETAILED DESCRIPTION

[0023] Reference Figures 1 to 7 , a driving device in an embodiment and a robot having the driving device are described. The driving device in this embodiment is arranged at a joint of the robot. The joint makes other components rotate relative to one component of the robot around a predetermined rotation axis.

[0024] Figure 1 1 is a perspective view of a robot in this embodiment. The robot 1 in this embodiment is a multi-joint robot including a plurality of joints 10a to 10f. The robot 1 in this embodiment is a collaborative robot capable of working in collaboration with an operator. The collaborative robot is configured such that when a predetermined external force acts on the robot 1, the movement of the robot 1 is restricted.

[0025] The robot 1 includes a plurality of components that can rotate at the joints 10a to 10f. Each component is formed to rotate around a drive shaft J1 to J6 as a rotation axis. The drive device of this embodiment is arranged inside the joints 10a to 10f in order to drive the components of the robot 1. The robot of this embodiment has six drive shafts, but is not limited to this. A robot that can change its position and posture by any mechanism can be used.

[0026] The robot 1 of the present embodiment includes a base portion 14, a rotating base 13, an upper arm portion 12, a forearm portion 11, and a wrist portion 15 as components of the robot 1. The rotating base 13 rotates around a drive axis J1 relative to the base portion 14 fixed to the setting surface. The upper arm portion 12 rotates around a drive axis J2 relative to the rotating base 13. The forearm portion 11 rotates around a drive axis J3 relative to the upper arm portion 12. Furthermore, the forearm portion 11 rotates around a drive axis J4 parallel to the direction in which the forearm portion 11 extends. The robot 1 includes a wrist portion 15 supported by the forearm portion 11. The wrist portion 15 rotates around a drive axis J5. Furthermore, the wrist portion 15 includes a flange 16 that rotates around a drive axis J6. A working tool corresponding to the work performed by the robot device is fixed to the flange 16.

[0027] Figure 2 A cross-sectional view of the drive device in this embodiment is shown. Figure 1 and Figure 2In the robot 1 of the present embodiment, a driving device is arranged at each joint portion 10a to 10f. That is, one driving device is arranged at one joint portion. In the present embodiment, a driving device 2 for rotating the upper arm portion 12 around the driving axis J2 relative to the rotating base 13 is used as an example for description. The driving device 2 is arranged at the joint portion 10b. The driving device 2 is arranged, for example, so that the direction indicated by the arrow 95 becomes the direction toward the rotating base 13.

[0028] The drive device 2 includes a motor 45 including a rotor 45a and a stator 45b. The drive shaft J2 corresponds to the rotation axis of the motor 45 and the axial direction of the drive device 2. The rotor 45a is fixed to the shaft 21. The shaft 21 that transmits the rotational force of the motor 45 functions as an output shaft of the motor 45. The shaft 21 of this embodiment is a hollow shaft having a cylindrical shape. The shaft 21 rotates with the drive shaft J2 as the rotation axis.

[0029] The drive device 2 includes a torque sensor 27 for detecting the torque output from the drive device 2. The torque sensor 27 detects the torque around the drive axis J2 when the drive device 2 is driven. The robot device includes a robot 1 and a robot control device for controlling the robot 1. The robot control device receives a signal related to the torque via a communication cable as a communication line. The robot control device subtracts a torque related to the deadweight of the robot and a torque related to the movement of the robot from the torque detected by the torque sensor. The calculated torque corresponds to the external force applied to the robot.

[0030] The robot of this embodiment is a collaborative robot. When the external force is greater than a predetermined judgment value, the robot control device can limit the movement of the robot. For example, when an operator touches the robot, the detected external force becomes larger. When the external force is greater than the judgment value, the robot control device can stop the robot. Although the drive device of this embodiment includes a torque sensor, it is not limited to this method. The torque sensor may not be configured in the drive device.

[0031] The flange 26 is fixed to the torque sensor 27 by bolts 57. The flange 25 is fixed to the flange 26 by bolts 56. In the present embodiment, the torque sensor 27 and the flanges 25 and 26 are fixed to the frame of the swivel base 13.

[0032] The drive device 2 includes a motor unit 4, and the motor unit 4 includes a motor 45. The motor unit 4 can include at least one device of a speed reducer, a brake, and a rotation position detector. The respective devices are arranged coaxially in the direction along the rotation axis of the motor 45. The motor unit 4 of this embodiment includes a speed reducer 31 that amplifies the rotational force of the motor 45, an electromagnetic brake 46 that brakes the shaft 21, and an encoder 47 that detects the rotation position of the output shaft of the motor 45. The torque sensor 27, the speed reducer 31, the motor 45, the electromagnetic brake 46, and the encoder 47 are arranged in a row in sequence. In addition, at least one of the speed reducer, the electromagnetic brake, and the encoder may not be arranged in the motor unit.

[0033] The drive device 2 includes a frame 22 in which a motor 45 is arranged. The frame 22 of the present embodiment is fixed to the frame of the upper arm 12. The shaft 21 is supported in a rotatable manner by bearings 51 and 52. The drive device 2 includes a frame 23 in which an electromagnetic brake 46 is arranged. The frame 22 and the frame 23 are fixed to each other by fastening members such as bolts. In addition, a bearing fixing member 28 for fixing the bearing 52 is arranged between the frame 22 and the frame 23. The bearing fixing member 28 is fixed to the frame 23 by fastening members such as bolts. By removing the fastening member, the frame 23, 22 and the bearing fixing member 28 can be removed from the side opposite to the direction indicated by the arrow 95.

[0034] A protection tube 66 is disposed inside the shaft 21. The protection tube 66 is formed in a cylindrical shape along the inner surface of the shaft 21. Electric wires such as power cables, air pipes for supplying compressed air, or linear bodies such as communication cables are inserted into the protection tube 66. The protection tube 66 is fixed by the clamping portion 66a being clamped by the flange 26 and the torque sensor 27. By disposing the protection tube 66, the linear body can be disposed inside the joint portion 10b of the robot 1.

[0035] The shaft 21 of this embodiment has step portions 21a and 21b for limiting the movement of the shaft 21 in the direction in which the rotation axis extends. Bearings 51 and 52 are engaged with the step portions 21a and 21b. The bearing 51 is fixed by the frame 22, and the bearing 52 is fixed by the bearing fixing member 28.

[0036] The reducer 31 of the drive device 2 transmits the rotational force output by the motor 45 to the frame 22. The reducer 31 of the present embodiment is a wave gear reducer. The reducer 31 has a wave generating component 32 as an input part to which the rotational force is input. The wave generating component 32 is called a wave generator. The wave generating component 32 includes a hub 36 whose shape (planar shape) is an ellipse as viewed from the direction of the rotating axis and a ball bearing 37 arranged on the outer peripheral surface of the hub 36. The hub 36 functions as a cam whose planar shape is an ellipse. The hub 36 is fixed to the shaft 21, for example, by a key connection or the like.

[0037] The reducer 31 has an elastic tubular member 33 that can be elastically deformed. The elastic tubular member 33 is called a wheel. The elastic tubular member 33 has a plurality of first teeth 33a formed on the outer peripheral surface. The elastic tubular member 33 is formed to deform with the rotation of the hub 36. The elastic tubular member 33 of this embodiment is fixed to the frame 22 with a bolt 55. The elastic tubular member 33 functions as an output shaft of the reducer 31.

[0038] The speed reducer 31 includes an annular member 34 disposed outside the elastic cylindrical member 33. The annular member 34 is called a rigid wheel. The annular member 34 is made of a rigid body that does not elastically deform. A second tooth portion that engages with the first tooth portion 33a is formed on the inner circumference of the annular member 34.

[0039] A main bearing 41 is arranged on the side of the annular member 34. The main bearing 41 of this embodiment is a cross roller bearing. The main bearing 41 has an inner ring 41a and an outer ring 41b. The inner ring 41a is fixed to the flange 25 and the annular member 34 by bolts 39. The outer ring 41b is fixed to the frame 22 together with the elastic cylindrical member 33 by bolts 55. In this embodiment, the wave generating member 32 rotates, while the annular member 34 is fixed and does not rotate. When disassembling the drive device 2, the bolts 56 and 57 are removed, and the torque sensor 27 and the flange 26 are removed from the flange 25. By removing the bolts 39 and the bolts 55, the reducer 31 and the main bearing 41 can be removed from the frame 22.

[0040] Since the hub 36 of the wave generating member 32 has an elliptical shape, the first tooth portion 33a of the elastic cylindrical member 33 and the second tooth portion of the annular member 34 are engaged with each other in the direction of the major axis of the ellipse. Here, the number of teeth of the first tooth portion 33a of the elastic cylindrical member 33 is less than the number of teeth of the second tooth portion of the annular member 34. For example, the number of teeth differs by two. When the wave generating member 32 rotates one circle, the elastic cylindrical member 33 rotates slightly due to the reduction ratio corresponding to the difference in the number of teeth of the tooth portions.

[0041] The decelerated rotational force is output to the outer ring 41b of the main bearing 41 fixed to the elastic cylindrical member 33 and the frame 22. The frame 22 of the drive device 2 is fixed to the frame of the upper arm 12. Therefore, the upper arm 12 is driven by the drive device 2 to rotate relative to the swivel base 13.

[0042] Oil seals 61 and 62 are arranged on the outer peripheral surface of the shaft 21 to prevent the lubricating oil inside from leaking out and to prevent foreign matter from entering from the outside. In addition, an oil seal 63 is arranged to prevent the lubricating oil inside the main bearing 41 from leaking out and to prevent foreign matter from entering from the outside.

[0043] The drive device 2 of the present embodiment includes an amplifier 5 as a motor control unit that supplies current to the motor 45. The amplifier 5 is also called a driver for driving the motor 45. The amplifier 5 of the present embodiment is fixed to the axial end of the motor unit 4. In particular, the amplifier 5 is coaxially fixed to the end face of the motor unit 4. The amplifier 5 is arranged at the endmost part of the components constituting the drive device 2. The amplifier 5 is coaxially arranged with the motor unit 4 including the motor 45. The torque sensor 27 is arranged at the end of the motor unit 4 on the opposite side to the end on which the amplifier 5 is arranged.

[0044] The amplifier 5 of this embodiment receives an action command from the robot control device, and controls the magnitude and frequency of the current supplied to the motor 45 based on the action command. The amplifier 5 includes a circuit for generating the current supplied to the motor 45. In the drive device of this embodiment, the amplifier 5 is configured for each motor of each motor. One amplifier 5 is configured for each motor 45, but it is not limited to this mode. One amplifier may also be configured for multiple motors. That is, it is also possible to configure an amplifier for supplying current for multiple motors.

[0045] Figure 3 The circuit diagram of the amplifier in the present embodiment is shown. The robot control device 3 is configured, for example, separately from the robot 1. The robot control device 3 includes a calculation processing device including a CPU (Central Processing Unit) as a processor. The robot control device 3 sends an action command to the drive device configured in each joint part 10a~10f. The AC current from the AC power supply 7 is converted into a DC current by the rectifier 8. The amplifier 5 of the present embodiment has the function of an inverter that converts the DC current from the rectifier 8 into an AC current.

[0046] The amplifier 5 has a capacitor 73 for smoothing the DC current. The amplifier 5 includes a main circuit 70 for generating a three-phase AC current from the DC current. The main circuit 70 is a bridge circuit including power elements 74 such as MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The amplifier 5 includes a processor 83 such as an MCU (Micro Controller Unit) that sends an operation command to each power element 74 of the main circuit 70.

[0047] The processor 83 receives an operation command for driving the motor 45 from the robot control device 3. The processor 83 receives an output signal of the encoder 47 for detecting the rotation position of the motor 45. In addition, a current detection sensor 75 is arranged on the power cable output from the main circuit 70. The processor 83 receives an output signal of the current detection sensor 75.

[0048] The processor 83 sends a switch command to the main circuit 70 based on the action command from the robot control device 3. The processor 83 can also send a command to control the power element 74 based on the output signal of the encoder 47, the output signal of the current detection sensor 75, and the output signal of the torque sensor 27. The processor 83, the capacitor 73, the power element 74 and other electrical components are arranged on the surface of the substrate included in the amplifier 5.

[0049] The drive device 2 of this embodiment has a line body for connecting with an external device. The line body includes a power cable for supplying electricity and a communication cable for sending signals. The line body of this embodiment includes a connecting component arranged at the front end of the cable for connecting with a substrate. The connecting component of the line body is connected to the component of the substrate.

[0050] The connecting part of the line body of this embodiment is composed of a connector. A connector that fits with the connector of the line body is arranged on the substrate of the amplifier. For example, a concave connector is arranged on the substrate. And a convex connector arranged at the front end of the line body is inserted or pulled out. In this way, the connector of the line body is formed so that the operator can install the connector of the line body on the connector of the substrate of the amplifier, or remove it from the connector of the substrate.

[0051] The connecting component of the line body is not limited to a connector, and any component that can be mounted on the substrate of the amplifier or removed from the substrate can be used. For example, a crimping terminal can be used as the connecting component of the line body. In addition, a terminal board that can be installed with a crimping terminal using screws can be configured on the substrate.

[0052] The umbilical body includes a component formed to be mounted on a substrate of the amplifier, or a connecting component detached from a component of the substrate, and the umbilical body can be easily detached from or mounted on the substrate. As a result, the amplifier can be easily separated from or fixed to the robot or the motor unit.

[0053] The command from the robot control device 3 is input to the processor 83 via the connector 82a arranged on the substrate. The output signal of the encoder 47 is input to the processor 83 via the connector 82b. The output signal of the current detection sensor 75 is input to the processor 83 via the connector 82c. The command output from the processor 83 is sent to the main circuit 70 via the terminal 77.

[0054] The current converted into direct current by the rectifier 8 is input to the main circuit 70 via the connector 72ba arranged on the substrate. Furthermore, the alternating currents of the U-phase, V-phase, and W-phase supplied from the main circuit 70 are supplied to the motor 45 via the connector 72a arranged on the substrate.

[0055] Figure 4 A perspective view of an amplifier in this embodiment is shown. Figure 5 A schematic top view of an amplifier in this embodiment is shown. Figures 2 to 5 , an arrow 95 indicates a direction in which the motor 45 is arranged relative to the amplifier 5. The arrow 95 indicates a direction along the drive axis J2 which is a rotation axis of the motor 45.

[0056] The amplifier 5 of this embodiment includes two substrates on which electrical components are arranged. The amplifier 5 includes a power substrate 71 on which electrical components for supplying power to the motor 45 are arranged. The amplifier 5 includes a control substrate 81 on which electrical components for generating signals for controlling the main circuit 70 are arranged. The power substrate 71 and the control substrate 81 are arranged to intersect the direction in which the drive shaft J2 extends.

[0057] In this embodiment, each power substrate 71 and control substrate 81 has a largest surface with the largest area. A plurality of electrical components are arranged on the largest surface. The power substrate 71 and control substrate 81 are arranged so that the largest surface intersects the drive axis J2 perpendicularly. Furthermore, the power substrate 71 and control substrate 81 are arranged so that the largest surfaces are parallel to each other.

[0058] In the amplifier of this embodiment, the substrate on which the electronic components are arranged is composed of a power substrate and a control substrate, but the present invention is not limited to this embodiment. The substrate on which the electronic components are arranged may be one. Alternatively, three or more substrates may be arranged.

[0059] The control substrate 81 is fixed to the power substrate 71 by the spacing bolts 67a. One spacing bolt 67a fixes the control substrate 81 with a nut 67c. The other spacing bolts 67a fix the control substrate 81 by clamping the spacing bolts 67b and the control substrate 81. The control substrate 81 is fixed to the fitting 68 by the spacing bolts 67b. The control substrate 81 is clamped by the spacing bolts 67a and the spacing bolts 67b.

[0060] The accessory 68 is formed in a circular ring shape. The accessory 68 is a component for fixing the amplifier 5 to the frame 23 of the motor unit 4. The accessory 68 has a threaded hole 68c for fixing the spacing bolt 67b. In this embodiment, the power substrate 71, the control substrate 81 and the accessory 68 are fixed as a whole by the spacing bolts 67a and 67b. The fixing method of multiple substrates is not limited to this method, and they can be fixed to each other by any components.

[0061] The amplifier 5 of this embodiment is formed so as to be detachable from the motor unit 4 by an operator's operation, and the fitting 68 has a protruding portion 68a protruding radially outward. A hole portion 68b for inserting a bolt 69 as a fastening member is formed in the protruding portion 68a. Figure 2 The end of the frame 23 of the motor unit 4 is formed with an extension portion 23a extending radially outward. A threaded hole is formed in the extension portion 23a. The extension portion 68a of the accessory 68 is fixed to the extension portion 23a of the frame 23 with a bolt 69. In this way, the amplifier 5 is directly fixed to the end of the motor unit 4 with the bolt 69. The operator can remove the amplifier 5 from the drive device 2 by removing the bolt 69.

[0062] A through hole 71c is formed in the center of the power substrate 71. Also, a through hole 81c is formed in the center of the control substrate 81. The shaft 21 and the protection tube 66 are inserted through the through holes 71c and 81c.

[0063] Reference Figures 2 to 5 The power substrate 71 is provided with capacitors 73a, 73b, and 73c having a function of smoothing direct current. The power substrate 71 is provided with a connector 72a for supplying current to the motor 45. The power substrate 71 is provided with a connector 72ba to which a power cable 86a for receiving current from the rectifier 8 is connected. The power substrate 71 is provided with a connector 72bb to which a power cable 86b for supplying power to other drive devices is connected. Furthermore, the power substrate 71 is provided with a connector 72c for supplying power to the electromagnetic brake 46.

[0064] A plurality of power elements 74 included in the main circuit 70 are arranged on the largest surface of the power substrate 71. In addition, a current detection sensor 75 for detecting the current output from the main circuit 70 is arranged. A terminal 77 for communicating with the circuit of the control substrate 81 is arranged on the power substrate 71. The terminal 77 is formed so as to be fitted with a terminal arranged on the back side of the control substrate 81.

[0065] The control substrate 81 has a shape obtained by cutting away a part of the outer circumference of a circular substrate. The control substrate 81 has a cutout portion 81d. The capacitors 73a, 73b, 73c and the connectors 72a, 72ba, 72bb, 72c of the power substrate 71 are arranged outside the cutout portion 81d.

[0066] The control substrate 81 is provided with a processor 83 that sends a command to the main circuit 70. The control substrate 81 is provided with a processing circuit 84 that processes input data. Here, the plurality of drive devices of the robot 1 of the present embodiment are configured to communicate serially with each other. One drive device is connected to the other drive devices with a communication cable. The control substrate 81 is provided with a connector 82aa to which a communication cable 87a that receives a signal from the robot control device 3 from the other drive devices is connected. The control substrate 81 is provided with a connector 82ab to which a communication cable 87b that sends a signal from the robot control device 3 to the other drive devices is connected.

[0067] The control board 81 is provided with a connector 82b to which a signal cable for receiving a signal from the encoder 47 is connected. A connector 82c to which a signal cable for receiving a signal from the current detection sensor 75 is connected is provided. A connector to which a signal cable for receiving a signal from the torque sensor 27 is provided may also be provided.

[0068] Figure 6 An enlarged schematic cross-sectional view of a joint portion when the drive device in the present embodiment is arranged at the joint portion of a robot is shown. Figure 6 It is a schematic cross-sectional view of the joint 10 b that rotates the upper arm 12 , which is another component, relative to the swivel base 13 , which is one component of the robot 1 .

[0069] Reference Figure 2 and Figure 6 The torque sensor 27 of the drive device 2 has a threaded hole 27a. A protrusion 13ab protruding inward is formed on the frame 13a of the rotary base 13. A through hole is formed in the protrusion 13ab. A bolt 58 is inserted through the through hole of the protrusion 13ab and fixed to the threaded hole 27a, thereby fixing the torque sensor 27 to the frame 13a of the rotary base 13.

[0070] The frame 22 of the motor unit 4 has a threaded hole 22a. The frame 12a of the upper arm 12 has a protruding portion 12ac protruding inward. A through hole is formed in the protruding portion 12ac. The bolt 59 is inserted through the through hole and fixed to the threaded hole 22a, thereby fixing the frame 22 of the drive device 2 to the frame 12a of the upper arm 12.

[0071] As described above, the frame 22 of the motor unit 4 rotates integrally with the elastic cylindrical member 33 of the speed reducer 31 by the driving of the motor 45. Furthermore, the frame 12a of the upper arm 12 fixed to the frame 2 of the motor unit 4 rotates integrally with the frame 22. As a result, the upper arm 12 rotates relative to the swivel base 13 about the drive axis J2.

[0072] A power cable 86a and a communication cable 87a are inserted into the protection tube 66. The power cable 86a and the communication cable 87a are connected to a drive device disposed at an adjacent joint portion 10a. Figure 4 and Figure 6 The power cable 86a is connected to the connector 72ba. The power cable 86b is connected to the connector 72bb. The power cable 86b is connected to a driving device disposed at the adjacent joint portion 10c.

[0073] Since the plurality of drive devices of the robot 1 of this embodiment communicate serially with each other, the information communicated by the communication cables 87a and 87b can include not only the action command but also the information detected by the sensor arranged in the robot 1. The communication cable 87a is connected to the connector 82aa of the drive device 2. Furthermore, the communication cable 87b connected to the connector 82ab of the drive device 2 is connected to the drive device of the adjacent joint 10c. In this way, the drive device 2 can be arranged inside the frame of the component of the robot 1.

[0074] The frame 12a of the upper arm 12 in this embodiment includes a main body 12aa and a cover 12ab that can be removed from the main body 12aa. The cover 12ab is fixed to the main body 12aa by a fastening member (not shown).

[0075] The cover 12ab is arranged to face the drive device 2. The cover 12ab has a size corresponding to the area where the drive device 2 is arranged. The cover 12ab has a shape that allows an operator to observe the entire end of the drive device 2 by removing the cover 12ab. In the present embodiment, the cover 12ab is formed larger than the radial size of the drive device 2. Furthermore, the cover 12ab is formed larger than the end surface of the amplifier 5.

[0076] Reference Figures 4 to 6The planar shape of the power substrate 71 is formed to be approximately circular. A recess 71a is formed on the outer periphery of the power substrate 71. The recess 71a is formed corresponding to the position of the bolt 69 that fixes the amplifier 5 to the frame 23. That is, the recess 71a is formed at a position corresponding to the hole 68b of the accessory 68. Similar to the power substrate 71, a recess 81a is formed on the outer periphery of the control substrate 81. The recess 81a is formed corresponding to the position of the hole 68b of the accessory 68.

[0077] Since the recessed portions 71a and 81a are formed, the operator can operate the bolt 69 that fixes the amplifier 5 to the motor unit 4 from the outside of the drive device 2. When the operator removes the amplifier 5 from the motor unit 4, the operator can operate the bolt 69 through the recessed portions 71a and 81a. By removing the bolt 69, the amplifier 5 can be removed from the motor unit 4 as a whole while the motor unit 4 is fixed to the robot. Alternatively, the amplifier 5 can be mounted on the motor unit 4 while the motor unit 4 is fixed to the robot.

[0078] In the joint part 10b of the present embodiment, when the cover part 12ab is removed, the operator can operate the bolts 69 fixing the amplifier 5 to the frame 23. The operator can remove the bolts 69 through the recessed part 71a formed in the power board 71 and the recessed part 81a formed in the control board 81.

[0079] The operator can remove the amplifier 5 from the motor unit 4 by removing the bolt 69. The amplifier 5 can be taken out of the frame 12a as a whole. Then, the connector of the filament body is pulled out from the connectors 72a, 72ba, 72bb, 72c of the power substrate 71. Furthermore, the amplifier 5 can be separated from the motor unit 4 by pulling out the connector of the filament body from the connectors 82aa, 82ab, 82b, 82c arranged on the control substrate 81.

[0080] Thus, in the drive device 2 of the present embodiment, only the amplifier 5 can be removed from the drive device 2, rather than removing the entire drive device 2 from the robot 1. In addition, the amplifier can be inspected and replaced. When the amplifier 5 is mounted on the motor unit 4, after the connectors of each line body are inserted into the connector of the substrate, the amplifier 5 can be fixed to the frame 23 of the motor unit 4 using the bolt 69.

[0081] When removing the drive device 2 from the housing 12a, 13a, the operator can operate the bolts 59 fixing the motor unit 4 to the housing 12a when removing the amplifier 5 from the drive device 2. The operator can remove the bolts 58, 59 to remove the drive device 2 from the housing 12a, 13a.

[0082] Figure 7 A schematic diagram of a driving device for a joint portion of a comparative example is shown. A driving device 91 of the comparative example includes an amplifier 92. The amplifier 92 of the comparative example includes a plurality of substrates. The amplifier 92 is fixed to an end of the motor unit 4 coaxially with the motor unit 4.

[0083] The drive device 91 of the comparative example does not have a torque sensor. The drive device 91 has an encoder 93 instead of a torque sensor. Two encoders 47 and 93 are arranged in the drive device 91. The encoder 47 is a primary encoder (first encoder) that detects the rotational position of the output shaft of the motor 45, i.e., the shaft 21. In contrast, the encoder 93 is a secondary encoder (second encoder) that detects the rotational position of the output shaft of the motor unit 4. The encoder 93 detects the rotational position of a component that rotates together with the output shaft of the reducer 31. The end face of the protective tube 66 is connected to the encoder 93.

[0084] The robot control device can calculate the amount of twisting of the output shaft of the reducer 31 relative to the input shaft of the reducer 31 (the output shaft of the motor 45) based on the rotational position output by the encoder 47, the reduction ratio of the reducer 31, and the rotational position output by the encoder 93. Based on the amount of twisting, the robot control device can calculate the torque being generated by the drive device 91. Furthermore, based on the torque of the drive device 91, the external force applied to the components of the robot can be calculated.

[0085] In the drive device 91 of the comparative example, an encoder 93 as a secondary encoder is arranged in order to calculate the torque generated by the drive device 91. The encoder 93 is arranged at the end of the drive device 91. That is, the motor 45, the electromagnetic brake 46, the encoder 47, the amplifier 92 and the encoder 93 are arranged in this order.

[0086] In the drive device 91 of the comparative example, even if the cover 12ab of the frame 12a is removed, the operator can observe the entire end of the drive device 91. However, since the encoder 93 is arranged at the end of the drive device 91, it is not possible to remove only the amplifier 92 from the drive device 91. When replacing the amplifier 92, the entire drive device 91 needs to be removed from the frames 12a and 13a of the robot 1.

[0087] Reference Figure 6 In contrast, in the drive device 2 of the present embodiment, a torque sensor is provided instead of the secondary encoder. The drive device 2 has a structure that does not include a rotation position detector for detecting the rotation position of the output shaft of the motor unit 4. The torque sensor 27 can be mounted on the output shaft of the reducer 31 or the fixed shaft of the reducer 31. The amplifier 5 can be fixed to the end of the motor unit 4. Furthermore, the torque sensor 27 can be arranged at the end of the motor unit 4 on the side opposite to the end on which the amplifier 5 is arranged.

[0088] The amplifier 5 of this embodiment is arranged at the axial end of the drive device 2. When replacing the amplifier 5 or inspecting the amplifier 5, the amplifier 5 can be easily removed from the motor unit 4 by the operation of the operator. In addition, the drive device may also include both a torque sensor and a secondary encoder. In this case, it is preferred to arrange the amplifier outside the secondary encoder in the axial direction of the drive device so that the amplifier is arranged at the end of the drive device.

[0089] Reference Figure 7 In the drive device 91 of the comparative example, it is not possible to remove only the amplifier 92 from the drive device 91. When replacing the amplifier 92, the drive device 91 needs to be removed from the robot. Here, in order to remove the drive device 91 from the frame 12a of the upper arm 12, it is necessary to form a work space around the drive device 91 so that the operator can operate the bolt 59. Therefore, the base plate of the amplifier 92 is formed small so that the work space is formed around the amplifier 92. That is, the base plate of the amplifier 92 is formed small so that the operator can operate the bolt 59.

[0090] For example, the base plate of the amplifier 92 can be formed so that the diameter DS is less than the diameter of the motor unit 4. Alternatively, the base plate of the amplifier 92 can be formed so that the diameter DS is less than the inner diameter DF of the protruding portion 12ac of the frame body on which the bolt 69 is arranged. In this way, in the drive device 91 of the comparative example, it is difficult to increase the diameter of the amplifier 92. Therefore, there is a concern that the number of substrates of the amplifier increases, and the amplifier becomes longer in the axial direction. In addition, there is a concern that the structure of the amplifier becomes complicated due to the increase in the number of substrates.

[0091] Reference Figure 6 In contrast, in the drive device 2 of the present embodiment, the amplifier 5 can be first removed from the drive device 2. Therefore, when the cover 12ab is removed, even if the bolts 59 are blocked by the substrate of the amplifier 5 and cannot be operated, the amplifier 5 can be removed from the drive device 2. Furthermore, the substrate of the amplifier 5 can be enlarged. In the present embodiment, the substrates of both the power substrate 71 and the control substrate 81 are formed so that the area of ​​the largest surface is larger.

[0092] For example, the amplifier substrate can be formed to be larger in the radial direction than at least one of the motor, the speed reducer, the brake, and the rotation position detector. Alternatively, the amplifier substrate can be formed to have a diameter larger than the diameter of the position of the bolt 59. Alternatively, the amplifier substrate can be formed to have a diameter larger than the inner diameter of the protrusion 12ac, which is the fixing part of the frame body where the bolt 59 is arranged.

[0093] In the drive device of this embodiment, the largest surface of the substrate where the electric components are arranged can be increased, so that more electric components can be arranged on one substrate. The number of substrates can be suppressed from increasing, and the amplifier can be suppressed from becoming larger.

[0094] In the present embodiment, the amplifier 5 is fixed to the end face of the motor unit 4 by a bolt 69 as a fastening member. With this structure, the amplifier 5 can be easily removed from the motor unit 4 by removing the bolt 69. The member for fixing the amplifier to the motor unit is not limited to fastening members such as screws, bolts, and nuts, and any member can be used. For example, a claw is formed in a member on one side of the frame of the motor unit and the amplifier. An engaging portion that engages with the claw is formed in the member on the other side. Then, a structure in which the claw is engaged with the engaging portion to fix the amplifier to the motor unit can also be used.

[0095] In this embodiment, a wave gear reducer is used as a reducer, but it is not limited to this mode. Any reducer such as a gear reducer can be used. In addition, as a reducer, it is preferable that the input shaft and the output shaft are arranged on the same line and can be arranged coaxially with the motor. For example, as a reducer, a planetary gear reducer can be used.

[0096] In this embodiment, a driving device that drives a component around the driving axis J2 of the robot is described, but the present invention is not limited to this form. The driving device in this embodiment can be used as a driving device that drives any component of the robot.

[0097] Furthermore, the drive device of this embodiment is disposed at the joint of the robot, but is not limited to this mode. The drive device of this embodiment can be applied to any device that causes two different components to rotate relative to each other around a rotation axis. For example, the drive device of this embodiment can be applied to a drive device that drives the wheels of an unmanned guided vehicle, a drive device that is disposed at a working tool and drives a component of the working tool, or a drive device of an automatic tool changer of a machine tool, etc.

[0098] The above-mentioned embodiments can be combined appropriately. In the above-mentioned drawings, the same or equivalent parts are marked with the same symbols. In addition, the above-mentioned embodiments are only examples and do not limit the invention. Moreover, the embodiments include changes to the embodiments shown in the claims.

[0099] Explanation of symbols

[0100] 1—robot, 2—driving device, 4—motor unit, 5—amplifier, 10a~10f—joint part, 12—upper arm part, 12a—frame, 13—rotating base, 13a—frame, 21—axis, 27—torque sensor, 27a—threaded hole, 31—reducer, 45—motor, 46—electromagnetic brake, 47—encoder, 71—power substrate, 72a, 72ba, 72bb, 72c—connector, 81—control substrate, 82aa, 82ab, 82b, 82c—connector, 86a, 86b—power cable, 87a, 87b—communication cable.

Claims

1. A driving device, characterized in that: have: a motor unit comprising a motor; and a motor control unit that supplies current to the motor, The motor unit includes at least one of a speed reducer, a brake, and a rotation position detector. The motor control unit includes a substrate and a plurality of electrical components fixed to the substrate. The motor control unit is coaxially fixed to an end portion of the motor unit in a direction of a rotation axis of the motor, and is detachable from the motor unit by an operator's operation.

2. The driving device according to claim 1, characterized in that: The motor control unit is fixed to an end portion of the motor unit by a fastening member.

3. The driving device according to claim 1 or 2, characterized in that: A linear body is provided for connection with an external device. The filament body includes a connection component for connecting with the substrate. The connection member is formed as a member to be attached to the substrate or as a member to be detached from the substrate.

4. The driving device according to claim 3, characterized in that: The connecting member includes a connector or a crimping terminal.

5. The driving device according to any one of claims 1 to 4, characterized in that: The substrate is formed to be larger in a radial direction than at least one of the motor, the speed reducer, the brake, and the rotational position detector.

6. The driving device according to any one of claims 1 to 5, characterized in that: A torque sensor is provided for detecting the torque output from the motor unit. The torque sensor is disposed at an end portion of the motor unit opposite to an end portion at which the motor control unit is disposed.

7. The driving device according to any one of claims 1 to 6, characterized in that: The motor unit has a structure including a rotational position detector for detecting a rotational position of an output shaft of the motor, but not including a rotational position detector for detecting a rotational position of the output shaft of the motor unit.

8. The driving device according to any one of claims 1 to 7, characterized in that: The motor control unit is respectively configured for each of the motors.

9. A robot, characterized in that: have: The driving device according to claim 1; and A joint part that allows one component of the robot to rotate relative to another component. The driving device is disposed at the joint portion.

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