Drive device and robot provided with drive device

Abstract

The robot includes: a drive device having a hollow portion extending in a direction along a rotation axis; and an optical cable disposed so as to be inserted through the inside of the hollow part. The robot includes a first support member and a second support member that support the optical cable. The first support member is fixed to a member that is stationary when driven by the drive device. The second support member is fixed to a member that rotates when driven by the drive device. The first support member and the second support member are formed to support the optical cable on the rotation axis.

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 includes a working tool for performing work and a robot for moving the working tool. The robot can change the position and posture of the working tool by driving components such as an arm. The robot is provided with a driving device including a motor for moving the components. For example, a driving device for moving each component is provided at a joint of the robot. The driving device can rotate other components relative to one component.

[0003] It is known that a linear body such as a power cable and a signal line for driving a driving device is arranged inside a component such as an arm of a robot (for example, Japanese Patent Publication No. 2008-18475). In this case, a through portion is formed in a driving device arranged at a joint. The linear body is inserted through the through portion and arranged from the internal space of one component to the internal space of another component. For example, a pipe is arranged along a rotating shaft, and a linear body such as a power cable is arranged inside the pipe (for example, Japanese Patent Publication No. 2015-211999).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-211999

[0007] Patent Document 2: Japanese Patent Application Publication No. 2008-18475 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In the joint of the robot, the relative angles of the components change due to the rotation of other components relative to one component. In the case where a line body is arranged inside the component of the robot, the extending direction of the line body changes as the component rotates. Therefore, a force in a predetermined direction is applied to the line body arranged at the joint. For example, a bending force or a torsional force acts on the line body.

[0010] In the prior art, electric wires are used as communication lines for sending control signals. However, when electric wires are used as communication lines, there is a problem that the electric signal is easily affected by noise. Or, electromagnetic noise is sometimes generated from the electric wires. Therefore, as a communication line, an optical cable can be used instead of an electric wire. By using an optical cable as a communication line, it has the following characteristics: it will not become a source of electromagnetic noise and is not easily affected by noise from the surroundings. However, the optical cable may be damaged by the force applied by the movement of the components of the robot.

[0011] Solutions to Solve Problems

[0012] The robot of the disclosed method is provided with a driving device, which rotates the second component of the robot relative to the first component of the robot around the rotation axis. The robot is provided with a component constituting a hollow portion extending in the direction along the rotation axis. The robot is provided with an optical cable, which is arranged in a manner of being inserted into the interior of the hollow portion. The robot is provided with: a first support component, which is arranged on one side of the axial direction of the hollow portion and supports the optical cable; and a second support component, which is arranged on the opposite side of the one side of the axial direction of the hollow portion and supports the optical cable. The first support component is fixed to a component that is stationary when driven by the driving device. The second support component is fixed to a component that rotates when driven by the driving device. The first support component and the second support component are formed to support the optical cable approximately on the rotation axis. The first support component and the second support component are configured so that when driven by the driving device, the second support component rotates relative to the first support component, and the optical cable twists between the first support component and the second support component.

[0013] The driving device of the disclosed method causes two different components to rotate relative to each other around a rotation axis, and has a hollow portion extending in a direction along the rotation axis. The driving device has a motor that generates a rotational force. The driving device has: a first support member, which is arranged on one side of the axial direction of the hollow portion and supports the optical cable in a manner of inserting through the interior of the hollow portion; and a second support member, which is arranged on the opposite side of the axial direction of the hollow portion and supports the optical cable. The first support member is fixed to a component of the driving device that is stationary when the motor is driven. The second support member is fixed to a component of the driving device that rotates when the motor is driven. The first support member and the second support member are formed to support the optical cable approximately on the rotation axis. The first support member and the second support member are configured so that when the motor is driven, the second support member rotates relative to the first support member, and the optical cable twists between the first support member and the second support member.

[0014] Effects of the Invention

[0015] According to the aspect of the present disclosure, it is possible to provide a driving device and a robot including the driving device, which can suppress damage to an optical cable serving as a communication line. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 2 This is a schematic cross-sectional view of a joint portion where a first drive device according to an embodiment is disposed.

[0018] Figure 3 This is a schematic partial cross-sectional view when the first drive device is viewed from the second supporting member side.

[0019] Figure 4 It is a perspective view of an optical fiber cable according to an embodiment.

[0020] Figure 5 is a schematic cross-sectional view of an optical cable.

[0021] Figure 6 This is a schematic cross-sectional view of a joint portion where a second drive device according to the embodiment is disposed.

[0022] Figure 7 It is a schematic cross-sectional view of a joint portion where a third drive device in the embodiment is arranged.

[0023] Figure 8 It is a schematic cross-sectional view of a joint portion where a fourth drive device in the embodiment is arranged.

[0024] Fig. 9 This is a schematic partial cross-sectional view of the fourth driving device as viewed from the second supporting member side.

[0025] Fig.10 This is a schematic partial cross-sectional view of a fifth driving device in the embodiment as viewed from the second supporting member side.

[0026] Fig.11 This is a schematic partial cross-sectional view of a sixth driving device in the embodiment as viewed from the second supporting member side. DETAILED DESCRIPTION

[0027] Reference Figures 1 to 11 , a driving device in an embodiment and a robot having the driving device are described. The driving device in this embodiment causes other components to rotate relative to one component of the robot around a predetermined rotation axis. An optical cable is configured as a communication line for sending information to the driving device or a communication line for receiving information from the driving device.

[0028] Figure 1: is a stereoscopic view of the robot of the present embodiment. The robot 1 of the present embodiment is a multi-joint robot including a plurality of joints 10a to 10f. The robot 1 of the present embodiment is a collaborative robot capable of working in collaboration with an operator. The collaborative robot is configured to limit the movement of the robot 1 when a predetermined external force acts on the robot 1. For example, the collaborative robot is configured to detect contact between the operator and the robot and stop the robot 1.

[0029] The robot 1 includes a plurality of components that can rotate in the joints 10a to 10f. Each component is formed to rotate around the drive shafts J1 to J6 as rotation axes. The drive device of this embodiment is arranged inside the joints 10a to 10f to drive the components of the robot 1.

[0030] The robot 1 includes a base portion 14 fixed to a setting surface and a rotating base 13 supported by the base portion 14. The rotating base 13 rotates around a driving axis J1 relative to the base portion 14. The upper arm 12 of the robot 1 rotates around a driving axis J2 relative to the rotating base 13. The forearm 11 of the robot 1 rotates around a driving axis J3 relative to the upper arm 12. Moreover, the forearm 11 rotates around a driving 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 driving axis J5. In addition, the wrist 15 includes a flange 16 that rotates around a driving axis J6. A working tool corresponding to the work performed by the robot device is fixed to the flange 16.

[0031] The robot 1 of this embodiment includes a base 14, a rotating base 13, an upper arm 12, a forearm 11, and a wrist 15 as components of the robot 1. The robot of this embodiment has six drive axes, but is not limited to this. A robot that changes position and posture by an arbitrary mechanism can be used.

[0032] Figure 2 A schematic cross-sectional view showing a joint portion including a first drive device according to the present embodiment. Figure 1 as well as Figure 2 The first drive device 2 is disposed at the joint portion 10b. The first drive device 2 rotates the upper arm 12 as the second component about the drive axis J2 as the rotation axis 71 relative to the rotation base 13 as the first component.

[0033] In this embodiment, the driving device that drives the upper arm 12 disposed at the joint 10b is used as an example for description, but the present invention is not limited to this method. The driving device of this embodiment can be disposed at a joint that causes the second component of the robot to rotate around the rotation axis relative to the first component of the robot. That is, the driving device of this embodiment is disposed at any joint and can cause any component to rotate.

[0034] The drive device 2 includes a motor 21 that generates a rotational force and a reducer 22 that amplifies the torque output by the motor 21. The drive device 2 is driven by the motor 21. The housing of the reducer 22 is fixed to the housing 12a of the upper arm 12. The motor 21 is fixed to the reducer 22. When the motor 21 is driven, the reducer 22 and the motor 21 rotate around the rotation axis 71 together with the housing 12a of the upper arm 12.

[0035] The drive device 2 includes a torque sensor 23 for detecting the torque output from the drive device 2. The torque sensor 23 of the present embodiment is composed of an inner ring portion, an outer ring portion, and a plurality of spoke-shaped detection portions connecting the inner ring portion and the outer ring portion. The outer ring portion of the torque sensor 23 is fixed to the housing 13a of the rotating base 13, and the inner ring portion is fixed to the output portion of the reducer 22. When the motor 21 is driven, the housing 13a of the rotating base 13 and the torque sensor 23 do not rotate but remain stationary. The torque sensor 23 detects the torque around the rotating shaft 71 when the drive device 2 is driven. The control device of the robot receives a signal related to the torque via a communication line. The control device of the robot 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.

[0036] The robot control device can limit the robot's movement when the external force is greater than a predetermined 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. In this case, the output shaft of the reducer can be fixed to the housing 13a of the rotating base 13.

[0037] The drive device 2 of the present embodiment includes a protective tube 24 as a component constituting a hollow portion 24a extending in the direction along the rotation axis 71. The space inside the protective tube 24 corresponds to the hollow portion 24a penetrating from one end face of the drive device 2 to the other end face. The component constituting the hollow portion 24a of the present embodiment is arranged in the drive device 2. The motor 21 has a hollow portion 21a extending in the direction along the rotation axis 71. The speed reducer 22 has a hollow portion 22a extending in the direction along the rotation axis 71. The torque sensor 23 has a hollow portion 23a extending in the direction along the rotation axis 71. In the present embodiment, these hollow portions 21a, 22a, 23a have substantially the same inner diameter and are arranged coaxially. The protective tube 24 is arranged inside the hollow portions 21a, 22a, 23a in a manner penetrating the hollow portions 21a, 22a, 23a. In the present embodiment, the protective tube 24 is arranged at the joint portion 10b of the robot 1. Furthermore, the hollow portion 24a is formed coaxially with the rotating shaft 71, but is not limited to this form. The axis of the hollow portion 24a may be away from the rotating shaft 71. In addition, the component constituting the hollow portion may also be a component disposed outside the drive device. That is, the hollow portion for inserting the optical cable may not be formed inside the drive device. For example, the hollow portion may also be formed in the housing of the component of the robot.

[0038] The protection tube 24 of the present embodiment is formed of resin. The line body can be inserted into the interior of the protection tube 24. In the present embodiment, the component extending in a linear shape is referred to as a line body. At least a part of the line body of the present embodiment is laid inside the shell of the component of the robot 1 such as an arm. The protection tube 24 is configured to protect the line body arranged inside. The flange portion at the front end of the protection tube 24 is fixed to the inner ring portion of the torque sensor 23. The protection tube 24 maintains a stationary state when the motor 21 is driven. In addition, the protection tube 24 may not be configured. For example, the hollow portions 21a, 22a, and 23a may constitute a hollow portion that passes through the drive device. In this case, the motor 21, the reducer 22, and the torque sensor 23 are equivalent to the components constituting the hollow portion.

[0039] In the robot 1 of the present embodiment, a driving device is arranged at each joint 10a to 10f. That is, one driving device is arranged at one joint. The plurality of driving devices of the robot 1 of the present embodiment are configured to communicate serially with each other. The driving device 2 includes a driver 25 for controlling the power supplied to the motor 21. The driver 25 includes, for example, an inverter, which converts direct current into alternating current and supplies it to the motor 21. A signal for controlling the motor 21 is sent from the robot's control device to the driver 25.

[0040] In this embodiment, as a communication line connected to the driver 25, an optical cable 51 is used instead of an electric wire. That is, the optical cable 51 is used as a signal line of the driver 2. The optical cable 51 connects the driver devices arranged at each joint to each other. Alternatively, the optical cable 51 connects the driver devices arranged at the joint to the control device of the robot. For example, an electrical signal can be converted into an optical signal, and the signal can be sent or received through the optical cable.

[0041] In this embodiment, any communication protocol that can perform serial communication through an optical cable can be used. For example, a communication protocol that performs optical communication through the same method as industrial Ethernet (registered trademark) such as EtherCAT (registered trademark) or field buses such as RS-485 can be used. In addition, the communication method of the robot's drive device is not limited to serial communication, and any method can be used. For example, it can also be configured to perform parallel communication through an optical cable.

[0042] In this embodiment, the control device of the robot is connected to the driver of the driving device arranged on the driving shaft J1 through an optical cable. Figure 2 The driver 25 of the drive device 2 on the drive shaft J2 shown in the figure is connected. In addition, the driver 25 of the drive device 2 arranged on the drive shaft J2 is connected to the driver of the drive device arranged on the drive shaft J3 through an optical cable. In this way, the drive devices adjacent to each other are connected to each other through optical cables until the drive device arranged on the drive shaft J6.

[0043] The information communicated through the optical cable includes the position command of the motor of each drive device, the command of the rotation speed of the motor, the current command of the motor, and the voltage command of the motor. In other words, it includes information related to the electricity supplied to the motor. The information related to the electricity of each driver is generated by the control device of the robot and received by each drive device via the communication line.

[0044] In addition, the information communicated via the optical cable can include information detected by sensors configured on the robot. For example, it includes information related to the position or speed detected by a rotation position detector (encoder) installed on the motor, and information related to the current detected by a current detector configured on the driver. Alternatively, it may also include information related to the torque output from the torque sensor. Information related to the output of these sensors is included in the signal output from the driver. The information communicated via the optical cable includes at least one of the aforementioned multiple information.

[0045] The driver 25 of the driving device 2 includes a communication device 26 for sending and receiving information through optical cable communication. The communication device 26 in this embodiment is arranged in the driving device 2. Figure 2The driver of the driving device disposed on the driving shaft J1 is connected to the optical cable 50. The optical cable 50 is connected to the optical cable 51 via the connector 66. The optical cable 51 is inserted through the hollow portion 24a inside the protection tube 24. The optical cable 51 is connected to the optical cable 53 extending from the communication device 26 of the driver 25 via the connector 66.

[0046] In addition, another optical cable 54 extending from the communication device 26 of the driver 25 is connected to the optical cable 52 via the connector 66. The optical cable 52 is connected to the driver of the driving device arranged on the driving shaft J3. In this way, by using an optical cable as a communication line and arranging a communication device for optical communication in the robot 1, optical communication can be implemented.

[0047] The optical cable of this embodiment includes at least two optical fibers as two signal lines. One signal line sends a signal from a driving device arranged on the driving shaft J1 to a driving device arranged on the driving shaft J6. The other signal line sends a signal from a driving device arranged on the driving shaft J6 to a driving device arranged on the driving shaft J1.

[0048] A power cable for supplying power to the drive motor 21 is connected to the driver 25 of the drive device 2. In the first drive device 2, the power cable for supplying power to the motor 21 can be laid, for example, outside the housing of the robot. In this way, the power cable may not be arranged inside the components of the robot.

[0049] The signal from the driver of the drive device disposed on the drive shaft J1 includes a signal for driving the motor 21 of the drive shaft J2. For example, it includes a signal for controlling an inverter that generates a current supplied to the motor 21. The driver 25 of the drive device 2 supplies power to the motor 21 based on the signal for driving the motor 21.

[0050] In addition, the driver 25 of the drive device 2 includes information related to the output of the sensor configured in the drive device 2 in the output signal. For example, the driver 25 includes at least one of the information related to the output of the torque sensor 23, the output of the rotation position detector, or the output of the current detector in the signal output from the driver 25.

[0051] The communication device 26 of the present embodiment is disposed inside the housing 12a of the upper arm 12, which is the second component of the robot 1. By disposing the communication device 26 inside the housing of the component of the robot, it is possible to suppress the robot from becoming larger.

[0052] Figure 3 A partial cross-sectional view showing a portion of the second support member in the first drive device. Figure 2 as well as Figure 3The drive device 2 of this embodiment has a first support member 31 and a second support member 32 that support the optical cable 51. Each of the first support member 31 and the second support member 32 is formed in a manner of supporting a point of the optical cable 51. The first support member 31 is fixed to a member that is stationary when the drive device 2 is driven. In the example here, the first support member 31 is fixed to the housing 13a of the rotating base 13. Alternatively, the first support member 31 may be fixed to the inner ring portion of the torque sensor 23.

[0053] The second support member 32 is fixed to a member that rotates when the drive device 2 is driven. In the example here, the second support member 32 is fixed to the housing of the motor 21. When the motor 21 is driven, the second support member 32 rotates around the rotation axis 71 together with the housing of the motor 21 as shown by the arrow 91. In addition, the second support member 32 may also be fixed to the housing 12a.

[0054] exist Figure 2 as well as Figure 3 , the robot is shown to be stopped at a reference position. The second support member 32 is arranged at the same phase as the first support member 31. The first support member 31 and the second support member 32 support the linear body such as the optical cable 51 in a manner that the linear body is bent in the interval between the first support member 31 and the second support member 32.

[0055] In the present embodiment, the linear body is fixed to the first support member 31 and the second support member 32 in the same manner. The first support member 31 has a fixing portion 31a at the front end. The fixing portion 31a has a plate-like shape. The optical cable 51 is fixed to the fixing portion 31a by a binding band 41. Similarly, the second support member 32 has a fixing portion 32a at the front end. The fixing portion 32a is formed in a plate shape. The optical cable 51 is fixed to the fixing portion 32a by a binding band 42. The binding bands 41 and 42 can be composed of elastic members such as nylon. In addition, the fixing portions 31a and 32a of the present embodiment are formed in a manner facing the outside of the protective tube 24 in the direction of the rotation axis 71, but are not limited to this form, and the fixing portions can also be formed in a manner facing the inside of the protective tube 24 in the direction of the rotation axis 71. Moreover, the fixing portions can also be arranged inside the protective tube by bending each support member toward the inside of the protective tube.

[0056] Figure 4 A perspective view showing an optical fiber cable according to the present embodiment. Figure 5 A cross-sectional view showing an optical fiber cable according to the present embodiment. Figure 5It is a cross-sectional view when cut along a plane perpendicular to the direction in which the optical cable 51 extends. In the present embodiment, a linear component including a core wire is referred to as an optical fiber. For example, the core wire includes a core as a linear light propagation portion, and has a structure in which the periphery of the core is covered with resin. The core can be formed of plastic such as quartz glass or acrylic resin, for example. In addition, the optical fiber can have a structure in which the periphery of the core wire is further covered with a sheath such as resin. In the present embodiment, a communication line including at least one optical fiber is referred to as an optical cable. For example, the optical cable can have a structure in which a plurality of optical fibers are integrated by resin.

[0057] Reference Figure 4 as well as Figure 5 The optical cable 51 of this embodiment has a structure in which two optical fibers 51a and 51b are fixed to each other and integrated. The two optical fibers 51a and 51b are fixed to each other by a sheath 51c formed of resin. The optical fibers 51a and 51b are fixed in a manner extending parallel to each other.

[0058] Thus, the optical cable 51 of the present embodiment has a structure in which a pair of optical fibers 51a and 51b are fixed to each other. In the present embodiment, in order to implement serial communication, a communication line for transmitting information to the driving device of the driving shaft J6 at the front end of the robot 1 and a communication line for transmitting information from the driving shaft J6 at the front end to the driving shaft J1 and the control device of the robot are required.

[0059] The optical cable 51 of the present embodiment is composed of the minimum number of optical fibers 51a and 51b required for serial communication. In addition, since the two optical fibers 51a and 51b are fixed to each other and integrated, the diameter of the optical cable 51 can be reduced. As a result, the drive device 2 can be reduced. Alternatively, the proportion of the optical cable 51 in the hollow portion 24a becomes smaller, and other linear bodies can be arranged in the hollow portion 24a. In addition, with this structure, the workability when laying the optical cable inside the component parts such as the arm of the robot is improved. In addition, the optical cable of the present embodiment is composed of two optical fibers, but is not limited to this method. The optical cable can contain any number of optical fibers.

[0060] In this embodiment, in order to protect the optical cable 51, a buffer material 61 is wound around the optical cable 51. The buffer material 61 can be made of an elastic member such as sponge or rubber. The buffer material 61 can be arranged in the area where the binding bands 41 and 42 are fixed to the fixing parts 31a and 32a. Alternatively, refer to Figure 2 The buffer material 61 can be arranged around the optical cable 51 in the section from the connector 66 arranged on one axial side of the protection tube 24 to the connector 66 arranged on the other axial side of the protection tube 24. Alternatively, the buffer material may not be arranged around the optical cable.

[0061] In addition, the inventor has studied and experimented on the damage of the optical cable to various movements of the optical cable, and found that the optical cable is relatively weak to bending movement, but relatively strong to torsional movement. In other words, it was found that the movement of twisting the optical cable around the axis of the optical cable is stronger than the movement of changing the extension direction. Based on this feature, the inventor has conceived a structure that suppresses the bending movement of the optical cable and preferentially generates torsional movement, as in this embodiment.

[0062] exist Figure 2 In the state shown, the first supporting member 31 and the second supporting member 32 are arranged at the same phase. Figure 2 In the state shown, the second support member 32 is arranged at a predetermined reference position. The cross-sectional shape of the linear body in the first support member 31 and the cross-sectional shape of the linear body in the second support member 32 are symmetrical with respect to the central surface 73 of the hollow portion 24a in the direction of the axis (rotation axis 71). Figure 2 as well as Figure 3 The optical cable 51 is fixed to the fixing portions 31a and 32a in such a manner that the optical fibers 51a and 51b are arranged in the horizontal direction. The optical cable 51 is arranged on the rotating shaft 71.

[0063] In the present embodiment, the first support member 31 is arranged on one side of the hollow portion 24a in the axial direction. In particular, the first support member 31 is arranged on one side with respect to the axial center surface 73 of the hollow portion 24a of the protection tube 24. The second support member 32 is arranged on the opposite side of the one side of the hollow portion 24a in the axial direction. In particular, the second support member 32 is arranged on the opposite side of the first support member 31 with respect to the axial center surface 73 of the hollow portion 24a. The first support member 31 and the second support member 32 are arranged on opposite sides with respect to the center surface 73 of the hollow portion 24a. The first support member 31 and the second support member 32 are preferably arranged near the outlets on both sides of the hollow portion 24a.

[0064] The first supporting member 31 and the second supporting member 32 are formed so as to support the optical cable 51 substantially on the rotation axis 71. Here, "substantially supporting on the rotation axis" means supporting on the rotation axis or in the vicinity of the rotation axis. That is, the first supporting member 31 and the second supporting member 32 are formed so as to support the optical cable 51 on the rotation axis 71 or in the vicinity of the rotation axis 71. For example, referring to Figure 3 The fixing parts 31a and 32a are preferably arranged with the rotating shaft 71 inside the region of the optical cable 51 when a part of the fixing parts 31a and 32a is cut. Alternatively, for example, the center of gravity of the cross-sectional shape of the optical cable 51 is preferably arranged in the region of half the inner diameter of the protective tube 24.

[0065] When the motor 21 is driven, the second support member 32 rotates relative to the first support member 31. The second support member 32 rotates in the direction indicated by the arrow 91 about the rotation axis 71 together with the motor 21 and the upper arm 12. Even when the upper arm 12 rotates, the fixed portion 32a is maintained on the rotation axis 71 or in the vicinity of the rotation axis 71.

[0066] As the fixing portion 32a rotates around the rotation axis 71, the movable portion of the optical cable 51 is twisted between the first support member 31 and the second support member 32. Since the first support member 31 and the second support member 32 support the optical cable 51 at or near the rotation axis 71, it is possible to suppress the bending of the optical cable 51. Since the optical cable 51 is highly susceptible to damage from twisting motion, damage to the optical cable 51 can be suppressed.

[0067] In addition, in the present embodiment, when the phase of the first supporting member 31 is the same as the phase of the second supporting member 32, the optical cable 51 is supported in a flexural manner between the first supporting member 31 and the second supporting member 32. Therefore, when the motor 21 is driven to twist the optical cable 51, it is possible to suppress the application of strong tension in the extending direction of the optical cable 51.

[0068] Figure 6 This is an enlarged schematic cross-sectional view showing a joint portion of a second drive device including the present embodiment. The position of the support member of the second drive device 3 is different from that of the first drive device 2. In the second drive device 3, the first support member 33 is fixed to the inner peripheral surface of the protection tube 24. The optical cable 51 is fixed to the fixing portion 33a of the first support member 33 by the binding band 43. The first support member 33 is fixed to a member that is stationary when the motor 21 is driven. The first support member 33 supports the optical cable 51 on the rotating shaft 71 or in the vicinity of the rotating shaft 71.

[0069] The second support member 34 is fixed to the arm that rotates when the motor 21 is driven. The second support member 34 is fixed to the inner surface of the housing 12a of the upper arm 12. The optical cable 51 is fixed to the fixing portion 34a of the second support member 34 by the binding band 44. The second support member 34 is formed in such a manner that the optical cable 51 is supported on the rotating shaft 71 or in the vicinity of the rotating shaft 71 even when the motor 21 is driven. In the second driving device 3, the bending action of the optical cable 51 when the motor 21 is driven can be suppressed, and damage to the optical cable 51 can be suppressed.

[0070] Furthermore, the first supporting member can be fixed to a member that remains stationary even when the motor 21 is driven, and thus, for example, can be fixed to the inner surface of the housing 13a of the rotating base 13. On the other hand, the second supporting member can be fixed to a member that rotates when the motor 21 is driven. Therefore, for example, in the case where the motor includes an encoder, the second supporting member can also be fixed to the housing of the encoder.

[0071] Figure 7 An enlarged schematic cross-sectional view of a joint portion including the third drive device of the present embodiment is shown. The third drive device 4 is different in orientation relative to the components of the robot 1 compared to the first drive device 2 and the second drive device 3. In the third drive device 4, the motor 21 and the reducer 22 are fixed to the housing 13a of the rotating base 13. On the other hand, the torque sensor 23 is fixed to the housing 12a of the upper arm 12.

[0072] In the third drive device 4, the torque sensor 23 connected to the output shaft of the speed reducer 22 rotates together with the upper arm 12 when the motor 21 is driven. On the other hand, the motor 21 and the speed reducer 22 are kept stationary when the motor 21 is driven. In the third drive device 4, the first support member 35 is fixed to the housing of the motor 21. An optical cable 51 is fixed to the fixing portion 35a of the first support member 35 by a binding band 45. The second support member 36 is fixed to the inner ring portion of the torque sensor 23. An optical cable 51 is fixed to the fixing portion 36a of the second support member 36 by a binding band 46. Each fixing portion 35a, 36a is formed in a manner to support the optical cable 51 on the rotating shaft 71 or in the vicinity of the rotating shaft 71.

[0073] The driver 25 including the communication device 26 is arranged inside the housing 13a of the rotating base 13 as the first component. The driver 25 is connected to the driver of the driving device arranged on the driving shaft J1 via the optical cables 50 and 53. In addition, the driver 25 is connected to the driver of the driving device arranged on the driving shaft J3 via the optical cables 54, 51, and 52. The optical cable 51 is inserted into the hollow portion 24a inside the protective tube 24.

[0074] In the third driving device 4, when the motor 21 is driven, the fixing portion 36a of the second supporting member 36 rotates around the rotating shaft 71. The fixing portion 35a of the first supporting member 35 is stationary. As a result, the optical cable 51 generates a torsional motion. The bending motion of the optical cable 51 can be suppressed, and damage to the optical cable 51 can be suppressed. In addition, in the third driving device 4, the first supporting member can also be fixed to the housing 13a of the rotating base 13. In addition, the second supporting member can also be fixed to the housing 12a of the upper arm 12.

[0075] Figure 8An enlarged schematic cross-sectional view showing a joint portion including a fourth drive device according to the present embodiment. Fig. 9 A schematic partial cross-sectional view showing a portion of the second support member of the fourth drive device of the present embodiment. In the aforementioned drive devices 2, 3, and 4, an optical cable 51 is arranged in the hollow portion 24a inside the protective tube 24, but the present invention is not limited to this. A plurality of linear bodies can be arranged inside the components of the robot. In the hollow portion of the drive device, a plurality of linear bodies other than the optical cable 51 can be inserted in a manner that penetrates the joint portion.

[0076] Reference Figure 8 as well as Fig. 9 , the fourth drive device 5 is different from the first drive device 2 in that the first support member 29 and the second support member 30 support a plurality of linear bodies. Each support member 29, 30 is fixed with a plurality of linear bodies by means of strapping bands 39, 40. The linear body of the present embodiment includes: a power cable 56 as an electric wire for supplying electricity from the drive motor 21 to the driver 25; an air supply pipe 57 for supplying pressurized air for driving the working tool; an electric wire 58 for supplying backup electricity to the rotational position detector (encoder); and a communication cable 59 for sending a signal for driving the working tool. The communication cable 59 is composed of a cable and is therefore included in the electric wire. The linear body is not limited to this method. Any movable linear body that is resistant to torsion or bending can be used.

[0077] The strapping band 40 is arranged so as to surround a plurality of linear bodies. The strapping band 40 is fixed integrally to the fixing portion 30a so as to bundle a plurality of linear bodies. Each linear body is arranged so as to be inserted through the hollow portion 24a inside the protective tube 24. In the first support member 29, when the second support member 30 is arranged at the same phase as the first support member 29, the plurality of linear bodies are arranged so as to be plane-symmetrical with respect to the central plane 73 relative to the arrangement of the linear bodies of the second support member 30. In the section between the fixing portion 29a and the fixing portion 30a, the plurality of linear bodies are supported in a flexural manner. In addition, in the section between the fixing portion 29a and the fixing portion 30a, the plurality of linear bodies are not fixed but are arranged so as to be able to deform freely. In the section between the fixing portion 29a and the fixing portion 30a, the linear bodies are separated from each other when the driving device is driven, thereby suppressing damage to the linear bodies.

[0078] The first supporting member 29 and the second supporting member 30 support the optical cable 51 near the rotation axis 71. The first supporting member 29 and the second supporting member 30 support the power cable 56, the spare electric wire 58, and the communication cable 59 as electric wires at positions farther from the rotation axis 71 than the optical cable 51.

[0079] Among them, the inventor has studied and experimented on the damage of the electric wires, and found the following characteristics: when the electric wire bundle is subjected to reciprocating torsional motion, the closer it is to the rotating shaft, the shorter the life of the conductor part of the electric wire until it breaks due to metal fatigue. In the fourth drive device 5, by configuring the electric wires at a position away from the rotating shaft 71, the life of the electric wires can be extended. In addition, in the fourth drive device 5, the optical cable 51 is configured near the rotating shaft 71. Therefore, in the fourth drive device 5, the life of the optical cable 51, the power cable 56, the electric wire 58 and the communication cable 59 can be extended.

[0080] Thus, in the fixing parts 29a and 30a, the optical cable 51 is preferably arranged on or near the rotating shaft 71, and the line bodies other than the optical cable 51, such as the electric wire, are arranged around the optical cable 51. Alternatively, in the cross section of the bundle of multiple line bodies, the optical cable 51 can be arranged in the central part, and the electric wire can be arranged in the outer peripheral part outside the central part. According to this structure, the life of the line bodies of both the optical cable and the electric wire can be extended.

[0081] In addition, the air supply pipe 57 for supplying compressed air is formed of a flexible material. The air supply pipe 57 is formed of, for example, polyurethane. The air supply pipe 57 has the characteristic of being difficult to be damaged by both bending and twisting movements. Therefore, the air supply pipe 57 can be arranged at any position in the cross section of the line body bundle.

[0082] As a member for fixing the filament body to the fixing portion, in addition to the above-mentioned nylon belt, a metal binding belt can also be used. When a metal belt is used, in order to prevent the filament body from being damaged by contact with the metal belt, a buffer material is preferably arranged on the inner peripheral surface of the metal belt.

[0083] Fig.10 An enlarged schematic cross-sectional view showing a portion of the second support member of the fifth drive device of the present embodiment. In the fifth drive device, the arrangement of the plurality of filaments in the cross section of the support member is different from that of the fourth drive device 5. The fifth drive device includes a second support member 37 having a fixing portion 37a. The plurality of filaments are fixed to the fixing portion 37a by a binding band 47. The first support member supports the plurality of filaments in the same structure as the second support member 37.

[0084] In the fifth driving device, the optical cable 51 is in contact with the fixing portion 37a via the buffer material 61. The optical cable 51 is in contact with the approximate center of the width direction of the fixing portion 37a. In this state, the position of the fixing portion 37a is adjusted in such a manner that the optical cable 51 is arranged on the rotating shaft 71. A power cable 56 and an electric wire 58 are arranged around the optical cable 51. In addition, an air supply pipe 57 is arranged around the optical cable 51. In the fifth driving device, a plurality of linear bodies can be bundled in a state in which the optical cable 51 is in contact with the center of the width direction of the fixing portion 37a. Therefore, the optical cable 51 can be easily arranged on the rotating shaft 71 to fix the linear body.

[0085] Fig.11 An enlarged schematic cross-sectional view showing a portion of the second support member of the sixth driving device of the present embodiment. The sixth driving device includes a second support member 38 having a fixing portion 38a. The first support member supports the umbilical body with the same structure as the second support member 38.

[0086] In the sixth driving device, the optical cable 51 and the air supply pipe 57 are arranged near the rotating shaft 71. The power cable 56 and the electric wire 58 are arranged around the optical cable 51 and the air supply pipe 57. The optical cable 51 and the air supply pipe 57 are arranged in the central part of the hollow part 24a. The power cable 56 and the electric wire 58 are arranged in the outer peripheral part around the central part. The first supporting member and the second supporting member 38 support the electric wire at a position farther from the rotating shaft 71 than the optical cable 51 and the air supply pipe 57.

[0087] As described above, the electric wires are preferably arranged at a position away from the rotating shaft 71. The diameter of the air supply pipe 57 is large, so it can be used as a spacer. By arranging the optical cable 51 and the air supply pipe 57 near the rotating shaft 71 and arranging the electric wires around the optical cable 51 and the air supply pipe 57, the electric wires can be arranged at a position away from the rotating shaft 71.

[0088] In addition, in the sixth driving device, a metal member 48 having a U-shaped cross-section is used as a member for fixing the linear body to the fixed portion 38a. The metal member 48 is made of metal. The metal member 48 is fixed to the fixed portion 38a by a fastening member such as a bolt 49. In addition, in order not to damage the linear body, a buffer material may be arranged on the inner circumferential surface of the metal member 48.

[0089] In this way, the component for fixing the line body is not limited to the binding belt, and any component such as a metal part can be used. As a component for bundling a plurality of line bodies, a component formed of plastic with a U-shaped cross-section can also be used. Alternatively, the line body can be fixed to the fixing portion by an adhesive as a component for bundling a plurality of line bodies.

[0090] In addition, refer to Fig.10In the fifth driving device, a dedicated metal member for arranging the optical cable 51 on the rotating shaft 71 or near the rotating shaft 71 may be fixed to the fixing portion. In addition, other linear bodies may be arranged around the metal member, and a plurality of linear bodies may be fixed using a binding band or the like.

[0091] 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.

[0092] 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.

[0093] Explanation of symbols

[0094] 1—robot, 2, 3, 4, 5—driving device, 10a~10f—joint part, 12—upper arm, 12a—housing, 13—rotating base, 13a—housing, 21—motor, 23—torque sensor, 24—protective tube, 24a—hollow part, 26—communication device, 29, 31, 33, 35—support component, 30, 32, 34, 36, 37, 38—support component, 29a, 31a, 33a, 35a—fixing part, 30a, 32a, 34a, 36a, 37a, 38a—fixing part, 50, 51, 52, 53, 54—optical cable, 51a, 51b—optical fiber, 51c—sheath, 56—power cable, 57—air supply pipe, 58—electric wire, 59—communication cable, 71—rotating axis.

Claims

1. A robot, characterized in that: have: a drive device that rotates the second component of the robot relative to the first component of the robot about the rotation axis; a member constituting a hollow portion extending in a direction along the rotation axis; an optical cable arranged so as to be inserted through the interior of the hollow portion; A first supporting member, which is arranged on one side of the axial direction of the hollow portion and supports the optical cable; as well as a second supporting member disposed on the opposite side of the hollow portion in the axial direction and supporting the optical cable; The first supporting member is fixed to a member that is stationary when the driving device is driving. The second supporting member is fixed to a member that rotates when the driving device is driven. The first supporting member and the second supporting member are formed in a manner to support the optical cable substantially on the rotation axis. The configuration is such that when the driving device is driven, the second supporting member rotates relative to the first supporting member, and the optical cable is twisted between the first supporting member and the second supporting member.

2. The robot according to claim 1, characterized in that: The member constituting the cavity is arranged in the driving device.

3. The robot according to claim 1 or 2, characterized in that: Equipped with electric wires for supplying electricity, The electric wire is arranged so as to be inserted into the interior of the hollow portion. The first supporting member and the second supporting member support the electric wire at a position farther from the rotation axis than the optical cable.

4. The robot according to claim 3, characterized in that: An air supply pipe for supplying pressurized air is provided, The air supply pipe is made of a flexible material. The first supporting member and the second supporting member support the electric wire at a position farther from the rotation axis than the optical cable and the air supply pipe.

5. The robot according to any one of claims 1 to 4, characterized in that: The drive device includes a driver for controlling the power supplied to the motor. The driver includes a communication device for sending and receiving information communicated via the optical cable, The communication device is disposed inside a housing of the first component or inside a housing of the second component.

6. The robot according to any one of claims 1 to 5, characterized in that: With multiple joints, The components constituting the hollow portion are arranged at the joint portion. A drive device is configured for each joint. A plurality of drive devices are configured to communicate serially. The optical cable composed of two optical fibers is inserted into the cavity.

7. The robot according to claim 6, characterized in that: The optical cable has a structure in which two optical fibers are fixed to each other and integrated.

8. The robot according to any one of claims 1 to 7, characterized in that: The information communicated via the optical cable includes at least one of a position command of the motor, a rotation speed command of the motor, a current command, a voltage command, information related to the position or speed detected by a rotational position detector, information related to the current detected by a current detector, information detected by a sensor, and a signal for controlling a working tool.

9. A driving device that causes two different components to rotate relative to each other around a rotation axis and has a hollow portion extending in a direction along the rotation axis, the driving device comprising: an electric motor, which generates a rotational force; a first supporting member disposed on one side of the hollow portion in an axial direction and supporting the optical cable so as to be inserted into the hollow portion; and a second supporting member disposed on the opposite side of the hollow portion in the axial direction to the one side and supporting the optical cable; The first support member is fixed to a component of the drive device that is stationary when the motor is driven. The second supporting member is fixed to a component of a driving device that rotates when the motor is driven. The first supporting member and the second supporting member are formed in a manner to support the optical cable substantially on the rotation axis. The configuration is such that, when the motor is driven, the second supporting member rotates relative to the first supporting member, and the optical cable is twisted between the first supporting member and the second supporting member.

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