Drive device and robot provided with drive device

Abstract

The drive device includes: a motor unit including a motor; and a motor control unit that supplies current to the motor. The motor control unit includes a plurality of electrical components fixed to the substrate. The substrate is disposed so as to intersect the extension direction of the rotating shaft of the motor. The plurality of electrical components include a specific electrical component having a longitudinal direction vertically disposed from the substrate. The specific electrical component is fixed in a direction protruding from the substrate toward the inside of the drive device. The specific electrical component is disposed further outward than the motor unit in the radial direction.

Description

Technical Field

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

[0002] The robot device can be equipped with a robot having a joint portion with a changeable orientation of components 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. The robot is provided with a drive device including a motor and a reducer for moving the components (for example, Japanese Patent Publication No. 9-29671). In the case where the robot has a joint portion, a drive device for moving the components is sometimes provided at the joint portion. The drive device can be provided at each joint portion (for example, Japanese Patent Publication No. 2019-84607).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 9-29671

[0006] Patent Document 2: Japanese Patent Application Publication No. 2019-84607 Summary of the invention

[0007] Problems to be solved by the invention

[0008] The electric current generated based on the action command of the robot is supplied to the motor of the driving device. The electric current supplied to the motor is generated by an amplifier. In the driving device, an amplifier is sometimes configured in addition to the motor and the reducer. When multiple driving devices are configured, an amplifier is sometimes configured for each driving device.

[0009] The amplifier circuit includes electrical components such as capacitors, processors, and power elements. In addition, the amplifier is connected to cables such as power cables for receiving power from the outside and communication cables for receiving motion instructions from the robot control device. The cables are connected to the amplifier substrate through connectors.

[0010] However, the electrical components of the amplifier include electrical components that become taller when arranged on the substrate. For example, a rod-shaped capacitor has a long side direction, so the height becomes taller when installed on the substrate. In addition, a connector connected to a linear body such as a cable is inserted into a connector of the substrate. The height of the connector becomes taller when it is installed on the substrate. In the case of having such electrical components, the height of the amplifier becomes taller. Moreover, in the drive device having the amplifier, space is required for arranging tall electrical components such as capacitors and connectors. There is a problem that the drive device becomes longer and larger.

[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 control unit includes a plate-shaped substrate and a plurality of electrical components fixed to the substrate. The substrate is arranged in a manner intersecting with the extension direction of the rotation axis of the motor. The plurality of electrical components include a specific electrical component having a long side direction and erected from the substrate. The specific electrical component is fixed in a direction protruding from the substrate toward the inside of the drive device, and is arranged radially at a position closer to the outside than the motor unit.

[0013] The robot disclosed in the present invention includes the aforementioned drive device and a joint portion that rotates one component relative to another component. The drive device is disposed at the joint portion.

[0014] Effects of the Invention

[0015] According to the aspects of the present disclosure, it is possible to provide a small-sized driving device and a robot including the driving device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a perspective view of a robot according to an embodiment.

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

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

[0019] Figure 4 This is a schematic three-dimensional diagram of an amplifier.

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

[0021] Figure 6 This is a schematic plan view of a power substrate of the amplifier according to the embodiment.

[0022] Figure 7 It is a schematic plan view of a control substrate of the amplifier according to the embodiment.

[0023] Figure 8 It is an enlarged schematic cross-sectional view of a driving device including an amplifier according to a comparative example.

[0024] Fig. 9 This is an enlarged schematic cross-sectional view of a joint portion of a robot equipped with a drive device. DETAILED DESCRIPTION

[0025] Reference Figures 1 to 9, a driving device in an embodiment and a robot including the driving device are described. The driving device in this embodiment rotates other components relative to one component of the robot around a predetermined rotation axis.

[0026] Figure 1 1 is a perspective view of a robot according to the present embodiment. The robot 1 according to the present embodiment is a multi-joint robot including a plurality of joints 10a to 10f. The robot 1 according to the present embodiment is a cooperative robot capable of working in cooperation with an operator. The cooperative robot is configured to restrict the movement of the robot 1 when a predetermined external force acts on the robot 1.

[0027] The robot 1 includes a plurality of components that can rotate in 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 6 drive shafts, but is not limited to this. A robot that can change its position and posture by any mechanism can be used.

[0028] The robot 1 of the present embodiment includes a base portion 14, a rotating base 13, an upper arm 12, a forearm 11, and a wrist 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 12 rotates around a drive axis J2 relative to the rotating base 13. The forearm 11 rotates around a drive axis J3 relative to the upper arm 12. Moreover, the forearm 11 rotates around a drive axis J4 parallel to the extension direction of the forearm 11. The robot 1 includes a wrist 15 supported by the forearm 11. The wrist 15 rotates around a drive axis J5. In addition, the wrist 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.

[0029] Figure 2 A cross-sectional view showing a driving device according to this embodiment. Figure 1 as well as Figure 2 In the robot 1 of the present embodiment, a drive device is arranged at each joint 10a to 10f. That is, one drive device is arranged at one joint. In the present embodiment, a drive device 2 for rotating the upper arm 12 around the drive axis J2 relative to the rotating base 13 is used as an example for explanation. The drive device 2 is arranged at the joint 10b. The drive device 2 is fixed to the housing of the rotating base 13 and the housing of the upper arm 12. The drive device 2 is arranged in such a way that the direction indicated by the arrow 95 is toward the rotating base 13, for example.

[0030] The drive device 2 includes a motor 45 including a rotor 45a and a stator 45b. The drive shaft J2 is equivalent 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 acts as an output shaft of the motor 45. The shaft 21 of this embodiment is a hollow shaft with a cylindrical shape. The shaft 21 rotates with the drive shaft J2 as the rotation axis.

[0031] The drive device 2 includes a torque sensor 27 that detects 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 control device receives a signal related to the torque via a communication cable as a communication line. The robot control device subtracts the torque related to the robot's own weight and the torque related to the robot's movement from the torque detected by the torque sensor. The calculated torque corresponds to the external force applied to the robot.

[0032] The robot of this embodiment is a collaborative robot. The robot control device can limit the movement of the robot when the external force is greater than a predetermined judgment value. For example, if an operator touches the robot, the detected external force becomes larger. The robot control device can stop the robot when the external force is greater than the judgment value. The drive device of this embodiment includes a torque sensor, but is not limited to this method. The torque sensor may not be configured in the drive device.

[0033] 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 this embodiment, the torque sensor 27 and the flanges 25 and 26 are fixed to the housing 13a of the slewing base 13. The torque sensor 27 and the flanges 25 and 26 are immovable components relative to the housing 13a.

[0034] The drive device 2 includes a motor unit 4 having a motor 45. The motor unit 4 can include at least one of a reducer, a brake, and a rotational position detector. The respective devices are arranged in parallel along the direction of the rotation axis of the motor 45. The motor unit 4 of the present embodiment includes: a reducer 31 that amplifies the rotational force of the motor 45; an electromagnetic brake 46 as a brake that brakes the shaft 21; an encoder 47 as a rotational position detector that detects the rotational position of the motor 45; and a torque sensor 27. The torque sensor 27, the reducer 31, the motor 45, the electromagnetic brake 46, and the encoder 47 are arranged in a row in this order. In addition, at least one of the torque sensor, the reducer, the electromagnetic brake, and the encoder may not be arranged in the motor unit.

[0035] The drive device 2 includes a housing 22 in which a motor 45 is arranged. The housing 22 of the present embodiment is fixed to the housing of the upper arm 12. The shaft 21 is rotatably supported by bearings 51 and 52. The drive device 2 includes a housing 23 in which an electromagnetic brake 46 is arranged. The housing 22 and the housing 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 housing 22 and the housing 23. The bearing fixing member 28 is fixed to the housing 23 by fastening members such as bolts. By removing the fastening member, the housings 23, 22 and the bearing fixing member 28 can be removed from the side opposite to the direction indicated by the arrow 95.

[0036] 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 clamped by the flange 26 and the torque sensor 27 through the clamping portion 66a and fixed. By disposing the protection tube 66, the linear body can be disposed inside the joint portion 10b of the robot 1.

[0037] The shaft 21 of this embodiment has a step portion 21a and a step portion 21b for limiting the movement of the shaft 21 in the extending direction of the rotation axis. The step portions 21a and 21b are engaged with bearings 51 and 52. The bearing 51 is fixed by the housing 22, and the bearing 52 is fixed by the bearing fixing member 28.

[0038] The reducer 31 of the drive device 2 transmits the rotational force output by the motor 45 to the housing 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 portion of the input rotational force. 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.

[0039] The reducer 31 has an elastic tubular component 33 that can be elastically deformed. The elastic tubular component 33 is arranged on the outer side of the wave generating component 32. The elastic tubular component 33 is called a flexible gear. The elastic tubular component 33 has a plurality of first tooth portions 33a formed on the outer peripheral surface. The elastic tubular component 33 is formed in a manner that deforms as the wheel hub 36 rotates. The elastic tubular component 33 of this embodiment is fixed to the housing 22 by a bolt 55. The elastic tubular component 33 acts as an output portion of the reducer 31.

[0040] The speed reducer 31 includes an annular member 34 disposed outside the elastic cylindrical member 33. The annular member 34 is called a circular spline. The annular member 34 is made of a rigid body that does not deform elastically. The inner peripheral surface of the annular member 34 is formed with a second tooth portion that engages with the first tooth portion 33a.

[0041] 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 housing 22 together with the elastic cylindrical member 33 by bolts 55. In this embodiment, the wave generating member 32 rotates, but the annular member 34 is fixed in a non-rotating manner.

[0042] Since the hub 36 of the wave generating component 32 has an elliptical shape, the first tooth portion 33a of the elastic cylindrical component 33 and the second tooth portion of the annular component 34 engage with each other in the direction of the major axis of the ellipse. Among them, the number of teeth of the first tooth portion 33a of the elastic cylindrical component 33 is less than the number of teeth of the second tooth portion of the annular component 34. For example, the number of teeth differs by two. When the wave generating component 32 rotates one circle, the elastic cylindrical component 33 rotates slightly at a reduction ratio corresponding to the difference in the number of teeth of the tooth portions. The decelerated rotational force is output to the outer ring 41b of the main bearing 41 fixed to the elastic cylindrical component 33 and the housing 22. The housing 22 of the drive device 2 is fixed to the housing of the upper arm 12. Therefore, the upper arm 12 is driven by the drive device 2 to rotate relative to the rotary base 13.

[0043] 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 the invasion of foreign matter 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 the invasion of foreign matter from the outside.

[0044] 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 arranged at the axial end of the drive device 2. In the example here, it 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 amplifier 5 of the present 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 that generates the current supplied to the motor 45.

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

[0046] The amplifier 5 has one or more capacitors 73 for smoothing the DC current. The amplifier 5 includes a main circuit 70 for generating a three-phase AC current from a DC current. The main circuit 70 is a bridge circuit including a plurality of power elements 74. In the present embodiment, a three-phase AC current is generated and supplied to the motor 45. The main circuit 70 of the present embodiment includes six power elements 74. As the power element 74, a power semiconductor device such as a MOSFET (Metal-Oxide-Semiconductor Field-EffectTransistor), an IGBT (Insulated Gate Bipolar Transistor) or an IPM (Intelligent PowerModule) can be included.

[0047] The amplifier 5 includes a processor 83 that sends an operation command to each power element 74 of the main circuit 70. As the processor 83 that controls the main circuit 70, any processor such as MCU (Micro Controller Unit), LSI (Large Scale Integration) or CPU (Central Processing Unit) can be used.

[0048] 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 rotational 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.

[0049] The processor 83 sends a switch command of the pulse width modulation control to the main circuit 70 based on the action command from the robot control device 3. The processor 83 sends a command for driving each power element 74. At this time, the processor 83 may also send a command to control the power element 74 based on the output signal of the encoder 47 and the output signal of the current detection sensor 75. Alternatively, the processor 83 may also send a command to control the power element 74 based on the output signal of the torque sensor 27.

[0050] The processor 83, capacitor 73, power element 74 and other electrical components included in the amplifier 5 are arranged on the surface of the substrate included in the amplifier 5. The command from the robot control device 3 is input to the processor via the connector 82a arranged on the substrate. The output signal of the encoder 47 is input to the processor 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 connecting component 77.

[0051] In addition, the current converted into direct current by the rectifier 8 is input to the main circuit 70 via the connector 72ba. 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. In this way, a connector for connecting the line body to the circuit is arranged on the substrate of the amplifier 5. For example, a female connector is fixed to the substrate. Then, the male connector connected to the front end of the line body is inserted into or pulled out of the female connector.

[0052] Figure 4 A perspective view showing an amplifier according to this embodiment. Figure 5 A schematic top view of an amplifier according to this embodiment is shown. Figures 2 to 5 , an arrow 95 indicates the direction in which the motor 45 is arranged relative to the amplifier 5. The arrow 95 indicates the direction along the drive axis J2 which is the rotation axis of the motor 45.

[0053] The amplifier includes a plate-shaped substrate and a plurality of electrical components fixed to the substrate. The amplifier 5 of the present embodiment includes a power substrate 71 configured with electrical components for supplying power to the motor 45. The amplifier 5 of the present embodiment includes: a control substrate 81, which is configured with electrical components for generating signals for controlling instructions for the main circuit 70. Each power substrate 71 and the control substrate 81 are configured in a manner intersecting the direction in which the drive shaft J2 extends. In the present embodiment, each power substrate 71 and the control substrate 81 has a maximum surface with the largest area. A plurality of electrical components are configured on the maximum surface. The power substrate 71 and the control substrate 81 are configured in a manner such that the maximum surface intersects perpendicularly with respect to the drive shaft J2. In addition, the power substrate 71 and the control substrate 81 are configured in a manner such that the maximum surfaces are parallel to each other.

[0054] The control substrate 81 is fixed to the power substrate 71 by the spacing bolts 67a. The spacing bolts 67a have external threads at both ends in the axial direction. The spacing bolts 67a are fixed to the threaded holes 71b formed in the power substrate 71. In addition, one spacing bolt 67a fixes the control substrate 81 by the nut 67c. The other spacing bolts 67a fix the control substrate 81 by clamping the spacing bolts 67b and the control substrate 81.

[0055] The control substrate 81 is fixed to the metal fitting 68 via the spacing bolt 67b. In the present embodiment, the spacing bolt 67b has an external thread at one end and an internal thread at the other end. The external thread of the spacing bolt 67a is inserted into and fixed to the internal thread of the spacing bolt 67b. The control substrate 81 is clamped by the spacing bolt 67a and the spacing bolt 67b.

[0056] The metal fitting 68 is formed in a circular ring shape. The metal fitting 68 is a component for fixing the amplifier 5 to the housing 23 of the motor unit 4. The metal fitting 68 has a threaded hole 68c for fixing the spacing bolt 67b. The spacing bolt 67b is fixed by inserting the external thread into the threaded hole 68c. In the present embodiment, the power substrate 71, the control substrate 81 and the metal fitting 68 are fixed integrally by the spacing bolts 67a and 67b. The spacing bolts 67a and 67b act as spacers for separating the multiple substrates from each other at a predetermined distance. The fixing method of the multiple substrates is not limited to this method, and the substrates can be fixed to each other by any components.

[0057] The metal fitting 68 has a protruding portion 68a that protrudes outward in the radial direction. A hole portion 68b for inserting the bolt 69 is formed in the protruding portion 68a. The hole portions 68b are formed at predetermined intervals in the circumferential direction. Figure 2 The end of the housing 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 metal fitting 68 is fixed to the extension portion 23a by a bolt 69. In this way, the amplifier 5 is fixed to the housing 23 by the metal fitting 68.

[0058] A through hole 71c is formed in the center of the power substrate 71. In addition, a through hole 81c is formed in the center of the control substrate 81. The shaft 21 and the protective tube 66 are inserted into the through holes 71c and 81c. In this embodiment, the substrate on which the electronic components are arranged is composed of a power substrate and a control substrate, but is not limited to this mode. The substrate on which the electronic components are arranged may also be one sheet. Alternatively, three or more substrates may be arranged. Next, the electronic components arranged on each substrate are described.

[0059] Figure 6 A schematic plan view of a power substrate according to this embodiment is shown. Figure 3 , Figure 4 as well as Figure 6 The power substrate 71 is formed in a substantially circular planar shape. Electrical components for supplying current to the motor 45 are arranged on the power substrate 71 .

[0060] The power substrate 71 is provided with a screw hole 71b for fixing the spacer bolt 67a. A recessed portion 71a is formed on the outer periphery of the power substrate 71. The recessed portion 71a is formed at a position corresponding to the bolt 69 that fixes the amplifier 5 to the housing 23. That is, the recessed portion 71a is formed at a position corresponding to the hole 68b of the metal member 68. By forming the recessed portion 71a, the operator can operate the bolt 69 that fixes the amplifier 5 to the motor unit 4 from the outside of the robot 1. By removing the bolt 69, the amplifier 5 can be removed from the motor unit 4 as a whole.

[0061] The electrical components arranged in the amplifier 5 include electrical components having a long side direction. That is, they include electrical components having a shape extending in a long and thin manner. When the electrical components are mounted on the surface of the substrate, the height becomes higher. In this embodiment, the electrical components having a long side direction and arranged vertically on the largest surface of the substrate are referred to as specific electrical components. In addition, electrical components other than the specific electrical components are referred to as normal electrical components.

[0062] For example, capacitors 73a, 73b, and 73c formed in a cylindrical shape are arranged on the power substrate 71. The capacitors 73a, 73b, and 73c have a function of smoothing a DC current. The axial direction of the cylindrical shape of the capacitors 73a, 73b, and 73c is the long side direction. The capacitors 73a, 73b, and 73c are arranged in a manner that they are vertically arranged in the long side direction on the largest surface of the power substrate 71.

[0063] A connector 72a for supplying current to the motor 45 is arranged on the power substrate 71. A connector 72ba connected to a power cable 86a for receiving current from the rectifier 8 is arranged on the power substrate 71. A connector 72bb connected to a power cable 86b for supplying power to other drive devices is arranged on the power substrate 71. In addition, a connector 72c for supplying power to the electromagnetic brake 46 is arranged on the power substrate 71. The connectors 72a, 72ba, 72bb, and 72c have a long side direction that is erected from the largest surface of the power substrate 71. These capacitors 73a, 73b, and 73c and the connectors 72a, 72ba, 72bb, and 72c correspond to specific electrical components.

[0064] On the other hand, 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. Furthermore, a gate processor 76 is arranged as a processor for supplying current to the gate of each power element 74. The power element 74, the current detection sensor 75, and the gate processor 76 are formed in a plate shape, so the height from the largest surface of the power substrate 71 is low. These electrical components do not have a long side direction vertically arranged on the largest surface of the substrate, and therefore correspond to ordinary electrical components.

[0065] In addition, a connection component 77 for communicating with the circuit of the control substrate 81 is arranged on the power substrate 71. The connection component 77 is formed so as to be fitted with a connection component arranged on the back side of the control substrate 81. By assembling the amplifier 5, the connection component 77 of the power substrate 71 is fitted with the connection component of the control substrate 81, and the circuits of the two substrates are connected to each other. The connection component 77 is equivalent to a general electrical component.

[0066] In addition, the power element 74 of the present embodiment includes a MOSFET. As a power element, an IGBT is sometimes included. A power element including an IGBT has a long side direction and sometimes has a higher height. Such a power element is equivalent to a specific electrical component. Alternatively, as a capacitor, a plate-shaped chip capacitor with a lower height is sometimes configured. The chip capacitor does not have a long side direction set upright from the substrate, and therefore is equivalent to a normal electrical component.

[0067] Thus, the specific electrical component can include at least one of a capacitor, a power element, and a connector. As the connector, any connector for connecting the linear body to the substrate can be used. The specific electrical component is arranged on the outer periphery of the substrate along the circumferential direction.

[0068] Figure 7 A schematic plan view of a control substrate according to the present embodiment is shown. Figure 3 , Figure 4 as well as Figure 7 The control substrate 81 has a shape obtained by cutting off a part of the outer circumference from a circular substrate. The control substrate 81 has a cutout portion 81d. The capacitors 73a, 73b, 73c and connectors 72a, 72ba, 72bb, 72c of the power substrate 71 are arranged outside the cutout portion 81d. The control substrate 81 has a recessed portion 81a. The recessed portion 81a is formed in a manner corresponding to the position of the hole portion 68b of the metal member 68. When the operator removes the amplifier 5 from the motor unit 4, the bolt 69 arranged in the hole portion 68b can be operated via the recessed portion 81a. In addition, the control substrate 81 has a hole portion 81b for inserting the external thread of the spacing bolt 67a.

[0069] The largest surface of the control substrate 81 is provided with electrical components for performing control. A processor 83 for sending instructions to the main circuit 70 is provided on the control substrate 81. A processing circuit 84 for processing input data is provided on the control substrate 81. The processor 83 and the processing circuit 84 are formed in a plate shape. In the present embodiment, the processor 83 and the processing circuit 84 are equivalent to ordinary electrical components.

[0070] The plurality of drive devices of the robot 1 of the present embodiment are formed in a manner of serially communicating with each other. One drive device is connected to other drive devices via a communication cable. A connector 82aa connected to a communication cable 87a for receiving a signal from the robot control device 3 from other drive devices is arranged on the control substrate 81. A connector 82ab connected to a communication cable 87b for sending a signal from the robot control device 3 to other drive devices is arranged on the control substrate 81.

[0071] The control board 81 is provided with a connector 82b connected to a signal cable for receiving a signal from the encoder 47. A connector 82c connected to a signal cable for receiving a signal from the current detection sensor 75 is also provided. Furthermore, a connector connected to a signal cable for receiving a signal from the torque sensor 27 may be provided.

[0072] The connectors 82aa, 82ab, 82b, and 82c disposed on the control board 81 correspond to specific electrical components having a longitudinal direction and erected from the surface of the board. The connectors 82aa, 82ab, 82b, and 82c are disposed on the outer periphery of the control board 81 along the circumferential direction.

[0073] In this way, the specific electrical component can include at least one of a connector into which power from a power source is input, a connector into which action instructions for the motor are input, a connector into which information from a sensor is input, a connector for supplying power to the motor, and a connector for supplying power to the brake.

[0074] The specific electrical components in this embodiment are arranged on the radial outer periphery of the substrate. The specific electrical components are fixed in a direction protruding from each substrate toward the inner side of the axial direction of the drive device. In this embodiment, the specific electrical components are fixed in a direction protruding from each substrate toward one side of the motor 45. For example, the connector and the capacitor are arranged in a manner protruding from the power substrate 71 in the direction indicated by the arrow 95. In addition, the connector is arranged in a manner protruding from the control substrate 81 in the direction indicated by the arrow 95.

[0075] Reference Figure 2 as well as Figure 4 Specific electrical components such as the connectors 72a, 82aa and the capacitor 73a are arranged radially outward from the motor unit 4. More specifically, the specific electrical components are arranged radially outward from the components included in the motor unit 4.

[0076] In the example here, specific electrical components such as the connector 72a and the capacitor 73a disposed on the power substrate 71 are disposed on the radially outer side of the encoder 47. In addition, specific electrical components such as the connector 82b disposed on the control substrate 81 are disposed on the radially outer side of the encoder 47. By adopting this structure, it is possible to ensure space for arranging specific electrical components on the outer side of the motor unit 4, and the drive device 2 can be miniaturized.

[0077] Figure 8 An enlarged schematic diagram of a drive device including an amplifier of a comparative example is shown. The drive device 91 of the comparative example includes an amplifier 92 as a motor control unit. The amplifier 92 of the comparative example includes a power substrate 71 and a control substrate 81. Each electrical component is fixed to the substrate in a manner facing the outside of the drive device 91 in the direction of the rotation axis of the drive device 91. In particular, the connectors 72a, 72ba, 72bb, 72c and the capacitors 73a, 73b, 73c as specific electrical components are fixed to the power substrate 71 in a manner of being uprightly arranged in the direction opposite to the direction indicated by the arrow 95. In addition, in the control substrate 81, specific electrical components such as connectors 82aa, 82c are also fixed in a manner facing the outside of the drive device 91 in the direction of the rotation axis of the drive device 91.

[0078] The specific electrical components are fixed to the substrate so as to protrude outward, thereby increasing the space for arranging the amplifier 92. As a result, the axial length L of the drive device 91 increases. Thus, in the comparative example, the drive device 91 increases in size.

[0079] In contrast, Figures 2 to 7 In the drive device 2 of the present embodiment shown, the specific electrical components are arranged on the radially outer side of the motor unit 4, and the specific electrical components are arranged in a manner that the direction protruding from the substrate faces the inner side of the drive device, thereby enabling the specific electrical components to be arranged in the space around the motor unit. Therefore, the axial length of the drive device along the drive axis J2 can be shortened. As a result, the drive device 2 can be miniaturized.

[0080] Fig. 9 An enlarged schematic cross-sectional view of a joint portion of a robot in which the drive device according to the present embodiment is disposed is shown. Fig. 9 It is a schematic cross-sectional view of a joint portion 10 b of an upper arm 12 as another component rotating relative to a swivel base 13 as one component.

[0081] Reference Figure 2 as well as Fig. 9The torque sensor 27 of the drive device 2 has a threaded hole 27a. A flange portion 13ab is formed on the housing 13a of the rotary base 13. The torque sensor 27 is fixed to the housing 13a by fixing a bolt 58 in the threaded hole 27a. The stationary portion of the drive device 2 is fixed to the rotary base 13.

[0082] In addition, the housing 22 of the motor unit 4 has a threaded hole 22a. The housing 12a of the upper arm 12 has a flange portion 12ab having a shape protruding inward. By inserting a bolt 59 into the threaded hole 22a, the housing 22 of the drive device 2 is fixed to the housing 12a of the upper arm 12. The rotating part of the drive device 2 is fixed to the upper arm 12.

[0083] The housing 22 rotates integrally with the elastic cylindrical member 33 of the speed reducer 31 by the driving of the motor 45. Furthermore, the housing 12a of the upper arm 12 fixed to the housing 22 rotates integrally with the housing 22. As a result, the upper arm 12 rotates relative to the rotary base 13 about the drive axis J2.

[0084] 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 as well as Fig. 9 The power cable 86a is connected to the connector 72ba. Furthermore, the power cable 86b is connected to the connector 72bb. The power cable 86b is connected to the driving device arranged at the adjacent joint part 10c.

[0085] In order for the multiple drive devices of the robot 1 of this embodiment to perform serial communication with each other, the information communicated through the communication cables 87a and 87b can include, in addition to the motion instructions, 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. In addition, the communication cable 87b connected to the connector 82ab of the drive device 2 is connected to the drive device of the adjacent joint part 10c.

[0086] In this way, the drive device 2 can be arranged inside the housing of the component of the robot 1. The drive device 2 of this embodiment is small, so the joint 10b can be reduced. In the example here, the length of the drive axis J2 of the drive device 2 can be shortened, and the housing 12a in the joint 10b of the upper arm 12 can be miniaturized.

[0087] The housing 12a of the upper arm 12 in the present embodiment has a cover portion 12aa that can be removed from the main body. The cover portion 12aa is fixed to the main body of the housing 12a by a fastening member not shown. The cover portion 12aa has a size corresponding to the area where the drive device 2 is arranged. By removing the cover portion 12aa, the operator can see the entire end of the drive device 2. In the present embodiment, the cover portion 12aa is formed to be larger in radial direction than the drive device 2. Furthermore, the cover portion 12aa is formed in a manner larger than the end face of the amplifier 5.

[0088] In the joint part 10b of the present embodiment, the amplifier 5 can be separated from the motor unit 4 by removing the bolt 69 while the cover part 12aa is removed. The amplifier 5 can be removed integrally outside the housing 12a. Furthermore, the amplifier 5 can be removed from the drive device 2 by pulling out the connector from the amplifier 5. That is, only the amplifier 5 can be removed without removing the entire drive device 2 from the robot 1. Furthermore, the amplifier can be inspected or replaced. In addition, the drive device 2 can be removed from the housings 12a and 13a by removing the bolts 58 and 59.

[0089] In the present embodiment, the amplifier 5 is disposed at the end of the drive device 2, but is not limited to this mode. In the extension direction of the drive shaft of the drive device, any device may also be disposed outside the amplifier. For example, in the drive device, a secondary encoder is sometimes disposed instead of a torque sensor. For example, the secondary encoder is connected to a protective tube. Based on the rotation angle output from the primary encoder and the rotation angle output from the secondary encoder, the magnitude of the torsion of the constituent components around the drive shaft can be calculated. Moreover, the torque around the drive shaft can be calculated based on the magnitude of the torsion of the constituent components. Such a secondary encoder may also be disposed outside the amplifier.

[0090] In this embodiment, a wave gear reducer is used as a reducer, but the invention is not limited to this method. Any reducer such as a gear reducer can be used. In addition, as a reducer, it is preferred 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.

[0091] 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 of this embodiment can be used as a driving device that drives any component of the robot.

[0092] In addition, the drive device of this embodiment is configured 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 parts to rotate relative to each other around a rotation axis. For example, the device of this embodiment can be applied to a drive device that is configured 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.

[0093] The above-mentioned embodiments can be combined appropriately. In the above-mentioned figures, the same or equivalent parts are marked with the same symbols. In addition, the above-mentioned embodiments are illustrative and do not limit the invention. In addition, in the embodiments, changes to the embodiments shown in the scope of the technical solution are included.

[0094] Explanation of symbols

[0095] 1—robot, 2—driving device, 3—robot control device, 4—motor unit, 5—amplifier, 10b—joint, 12—upper arm, 13—rotating base, 21—axis, 22, 23—housing, 31—reducer, 45—motor, 46—electromagnetic brake, 47—encoder, 72a~72c—connector, 73a~73c—capacitor, 74—power element, 81—control substrate, 82a~82c—connector, J2—drive shaft.

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 control unit includes a plate-shaped substrate and a plurality of electrical components fixed to the substrate. The substrate is arranged to intersect with the extending direction of the rotating shaft of the motor. The plurality of electrical components include a specific electrical component having a long side direction and arranged upright from the substrate, The specific electric component is fixed in a direction protruding from the substrate toward the inside of the drive device, and is arranged radially outward of the motor unit.

2. The driving device according to claim 1, characterized in that: The motor unit includes at least one of a speed reducer, a brake, and a rotation position detector, At least one device is arranged in parallel with the motor in a direction along the rotation axis of the motor and is arranged radially inside the specific electric component.

3. The driving device according to claim 1, characterized in that: The specific electrical component includes at least one of a capacitor, a power element, and a connector connecting the filament body to the substrate.

4. The driving device according to any one of claims 1 to 3, characterized in that: The specific electrical component includes at least one of a connector to which power from a power source is input, a connector to which an action command of a motor is input, a connector to which information from a sensor is input, a connector to supply power to the motor, and a connector to supply power to a brake.

5. A robot, characterized in that: have: The driving device according to claim 1; and A joint part that rotates one component relative to another component. The driving device is arranged at the joint portion.

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