Robot and robot system

Abstract

The utility model provides a robot and a robot system. The robot is provided with a second arm with excellent weight balance. When a straight line intersecting with the second rotating shaft and the third rotating shaft is set as an imaginary central shaft of the second arm in a plan view along the direction of the second rotating shaft, the first motor and the middle pulley are located on one side of the imaginary central shaft, and the second motor is located on the other side of the imaginary central shaft. A through hole penetrating through the arm base in a direction along the second rotation axis is formed in the arm base, and the through hole is disposed so as to be biased toward the imaginary central axis when viewed in plan from the direction along the second rotation axis.

Description

Technical Field

[0001] This utility model relates to robots and robot systems. Background Technology

[0002] The robot described in Patent Document 1 is a SCARA robot, comprising: a base; a first arm rotatably connected to the base about a first rotation axis along the vertical direction; a second arm rotatably connected to the first arm about a second rotation axis along the vertical direction; and a working head disposed on the second arm. Furthermore, the working head has a spline nut and a ball screw nut arranged coaxially along the vertical direction, and a spline shaft inserted into the spline nut and the ball screw nut. In such a working head, if the spline nut is rotated, the spline shaft rotates about its central axis and a third rotation axis along the vertical direction, and moves linearly along the third rotation axis; if the ball screw nut is rotated, the spline shaft moves linearly along the third rotation axis.

[0003] Furthermore, the robot has a first drive mechanism for the spline shaft that rotates the spline nut and causes the spline shaft to rotate about a third rotation axis. The first drive mechanism for the spline shaft includes: a first motor; a drive pulley fixed to the rotation axis of the first motor; a driven pulley fixed to the spline nut; an intermediate pulley located between the drive pulley and the driven pulley, rotating about a fourth rotation axis along the vertical direction; a first belt wound around the drive pulley and the intermediate pulley; and a second belt wound around the intermediate pulley and the driven pulley.

[0004] Furthermore, the robot has a second spline shaft drive mechanism that rotates the ball screw nut and causes the spline shaft to move linearly along a third rotation axis. The second spline shaft drive mechanism includes: a second motor; a drive pulley fixed to the rotation axis of the second motor; a driven pulley fixed to the ball screw nut; and a belt wound around the drive pulley and the driven pulley.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-079111

[0006] However, when viewed from above along the direction of the second rotation axis, when the straight line intersecting the second and third rotation axes is taken as the imaginary central axis of the second arm, in the robot of Patent Document 1, only the intermediate pulley included in the first drive mechanism of the spline shaft is configured to be biased to one side of the imaginary central axis. Therefore, due to the weight of the intermediate pulley, the difference between the weight on one side and the weight on the other side relative to the imaginary central axis becomes larger, and there is a possibility that the driving accuracy of the second arm will be reduced. Utility Model Content

[0007] The robot of this utility model has the following features:

[0008] abutment;

[0009] The first arm is connected to the base and rotates about a first rotation axis relative to the base;

[0010] The second arm has an arm base connected to the first arm, and the second arm rotates relative to the first arm about a second rotation axis parallel to the first rotation axis.

[0011] A working head, disposed on the second arm, includes a splined shaft along a third rotation axis parallel to the first rotation axis, and a splined nut and a ball screw nut mounted on the splined shaft. When the splined nut rotates, the splined shaft rotates about the third rotation axis; when the ball screw nut rotates, the splined shaft moves linearly along the third rotation axis.

[0012] A first drive mechanism and a second drive mechanism for the spline shaft are disposed within the second arm. The first drive mechanism rotates the spline nut, causing the spline shaft to rotate about the third rotation axis. The second drive mechanism rotates the ball screw nut, causing the spline shaft to move linearly along the third rotation axis.

[0013] The first drive mechanism for the splined shaft includes: a first motor fixed to the arm base; a first pulley fixed to the rotating shaft of the first motor; a second pulley fixed to the splined nut; an intermediate pulley that rotates relative to the arm base about a fourth rotating shaft parallel to the first rotating shaft; a first belt wound around the first pulley and the intermediate pulley; and a second belt wound around the intermediate pulley and the second pulley.

[0014] The second drive mechanism for the splined shaft includes: a second motor fixed to the arm base; a third pulley fixed to the rotating shaft of the second motor; a fourth pulley fixed to the ball screw nut; and a third belt wound around the third and fourth pulleys.

[0015] When viewed from above along the second rotation axis, with the straight line intersecting the second and third rotation axes as the imaginary central axis of the second arm, the first motor and the intermediate pulley are located on one side of the imaginary central axis, and the second motor is located on the other side of the imaginary central axis.

[0016] A through hole is formed on the arm base, extending through the arm base in the direction along the second rotation axis. When viewed from above in the direction along the second rotation axis, the through hole is positioned biased toward one side of the imaginary central axis.

[0017] Alternatively, the third rotation axis may be located closer to the front end of the second arm than the fourth rotation axis.

[0018] When viewed from above along the direction of the second rotation axis, the through hole is located on the side of the third rotation axis that is closer to it than the fourth rotation axis.

[0019] Alternatively, when viewed from above along the direction of the second axis of rotation, the intermediate pulley overlaps with the third belt.

[0020] Alternatively, when viewed from above along the direction of the second rotation axis, the intermediate pulley overlaps with the imaginary central axis.

[0021] Alternatively, the intermediate pulley may have: a shaft extending along the fourth rotation axis; a first intermediate pulley disposed on the shaft and wound with the first belt; and a second intermediate pulley disposed on the shaft, located further from the arm base than the first intermediate pulley, and wound with the second belt.

[0022] The robot has a support component fixed to the arm base, which holds the portion of the shaft between the first intermediate pulley and the second intermediate pulley via a first bearing, and holds the portion of the shaft that is closer to the arm base than the second intermediate pulley via a second bearing.

[0023] Alternatively, when viewed from above in a direction orthogonal to the fourth rotation axis, the third belt is located between the first belt and the second belt.

[0024] Alternatively, the diameter of the first intermediate pulley can be larger than the diameter of the second intermediate pulley.

[0025] A weight-reducing portion is formed on the first intermediate pulley, which extends through the first intermediate pulley in the direction along the fourth rotation axis.

[0026] Alternatively, the robot may have a mounting component disposed on the second arm, which carries an inertial sensor module for measuring the inertia of the second arm.

[0027] When viewed from above along the direction of the second rotation axis, the mounting component overlaps with the imaginary central axis.

[0028] Alternatively, the robot may have an inertial sensor module, which is configured on the second arm and measures the inertia of the second arm.

[0029] When viewed from above along the direction of the second rotation axis, the inertial sensor module is located on the other side of the imaginary central axis.

[0030] Alternatively, the third rotation axis may be located closer to the front end of the second arm than the fourth rotation axis.

[0031] When viewed from above along the second rotation axis, the through hole is located closer to the third rotation axis than the fourth rotation axis.

[0032] When viewed from above along the second rotation axis, the through hole overlaps with the intermediate pulley, the intermediate pulley overlaps with the third belt, and the intermediate pulley overlaps with the imaginary central axis.

[0033] The intermediate pulley includes: a first intermediate pulley with the first belt wound around it; and a second intermediate pulley arranged with the first intermediate pulley along the direction of the fourth rotation axis, and with the second belt wound around it.

[0034] When viewed from above in a direction orthogonal to the fourth rotation axis, the third band is located between the first band and the second band.

[0035] The diameter of the first intermediate pulley is larger than that of the second intermediate pulley, and a weight-reducing portion is formed on the first intermediate pulley that extends through the first intermediate pulley in the direction along the fourth rotation axis.

[0036] The robot has an inertial sensor module disposed on the second arm. When viewed from above along the direction of the second rotation axis, the inertial sensor module overlaps with the imaginary central axis or is located on the other side biased towards the imaginary central axis. The inertial sensor module measures the inertia of the second arm.

[0037] The robot system of this utility model has the following features:

[0038] Robots; and

[0039] The control device controls the robot's drive.

[0040] The robot has the following characteristics:

[0041] abutment;

[0042] The first arm is connected to the base and rotates about a first rotation axis relative to the base;

[0043] The second arm has an arm base connected to the first arm, and the second arm rotates relative to the first arm about a second rotation axis parallel to the first rotation axis.

[0044] A working head, disposed on the second arm, includes a splined shaft along a third rotation axis parallel to the first rotation axis, and a splined nut and a ball screw nut mounted on the splined shaft. When the splined nut rotates, the splined shaft rotates about the third rotation axis; when the ball screw nut rotates, the splined shaft moves linearly along the third rotation axis.

[0045] A first drive mechanism and a second drive mechanism for the spline shaft are disposed within the second arm. The first drive mechanism rotates the spline nut, causing the spline shaft to rotate about the third rotation axis. The second drive mechanism rotates the ball screw nut, causing the spline shaft to move linearly along the third rotation axis.

[0046] The first drive mechanism for the splined shaft includes: a first motor fixed to the arm base; a first pulley fixed to the rotating shaft of the first motor; a second pulley fixed to the splined nut; an intermediate pulley that rotates relative to the arm base about a fourth rotating shaft parallel to the first rotating shaft; a first belt wound around the first pulley and the intermediate pulley; and a second belt wound around the intermediate pulley and the second pulley.

[0047] The second drive mechanism for the splined shaft includes: a second motor fixed to the arm base; a third pulley fixed to the rotating shaft of the second motor; a fourth pulley fixed to the ball screw nut; and a third belt wound around the third and fourth pulleys.

[0048] When viewed from above along the second rotation axis, with the straight line intersecting the second and third rotation axes as the imaginary central axis of the second arm, the first motor and the intermediate pulley are located on one side of the imaginary central axis, and the second motor is located on the other side of the imaginary central axis.

[0049] A through hole is formed on the arm base, extending through the arm base in the direction along the second rotation axis. When viewed from above in the direction along the second rotation axis, the through hole is positioned biased toward one side of the imaginary central axis. Attached Figure Description

[0050] Figure 1 This is a side view showing the robot according to the first embodiment.

[0051] Figure 2 This is a cross-sectional view showing the connection between the base and the first arm.

[0052] Figure 3 This is a sectional view of the second arm viewed from the lateral side.

[0053] Figure 4 This is a cross-sectional view of the second arm viewed from the other side laterally.

[0054] Figure 5 It is a magnified three-dimensional view showing the front end of the frame.

[0055] Figure 6 This is a top view showing the interior of the second arm.

[0056] Figure 7 This is an enlarged cross-sectional view showing the middle pulley.

[0057] Figure 8 This is an enlarged cross-sectional view showing the front end of the frame.

[0058] Figure 9 This is a top view used to illustrate the configuration of the through holes formed in the arm base.

[0059] Figure 10 This is a top view showing the interior of the second arm of the robot according to the second embodiment.

[0060] Explanation of reference numerals in the attached figures

[0061] 1…robot, 10…base, 100…robot system, 11…first arm, 12…second arm, 121…arm base, 121a…through hole, 122…frame, 123…cover, 123a…insertion hole, 123b…guide wall, 13…working head, 131…spline nut, 132…ball screw nut, 133…spline shaft, 14…pipe, 141…base opening, 142…front opening, 16…carrying component, 17…brake release button, 181…connector, 182…connector, 2 1…First arm drive mechanism, 211…Reducer, 211a…Rigid wheel, 211b…Flexible wheel, 211c…Wave generator, 212…Motor, 22…Second arm drive mechanism, 221…Reducer, 221a…Rigid wheel, 221b…Flexible wheel, 221c…Wave generator, 222…Motor, 23…Splined shaft first drive mechanism, 231…First motor, 232…Reduction mechanism, 232a…First reduction mechanism, 232b…Second reduction mechanism, 24…Splined shaft second drive mechanism, 241…Second motor, 242…Reduction mechanism, 242a…Third pulley, 242b…Fourth pulley, 242c…Third belt, 243…Brake, 243a…Plate, 243b…Plate, 31…Wiring, 32…Wiring, 33…Wiring, 41…Support component, 42…Support component, 501…Bearing, 502…Bearing, 51…First pulley, 52…Second pulley, 54…Intermediate pulley, 541…First intermediate pulley, 541a…Belt mounting part, 541b…Connecting part, 541c…Weight reduction part, 542…Second intermediate pulley Wheel, 543…shaft, 55…first belt, 56…second belt, 59…support member, 591…first holding part, 592…second holding part, 593…connecting part, 6…inertial sensor module, 61…substrate, 62…angular velocity sensor, 8…brake control substrate, 82…light-emitting element, 85…lens, 9…control device, 91…control substrate, 92…power supply substrate, A…imaginary central axis, J1…first rotating axis, J2…second rotating axis, J3…third rotating axis, J4…fourth rotating axis, L…light. Detailed Implementation

[0062] The robot and robot system of this utility model will now be described in detail based on the embodiments shown in the accompanying drawings.

[0063] First Implementation Method

[0064] Figure 1 This is a side view showing the robot according to the first embodiment. Figure 2 This is a cross-sectional view showing the connection between the base and the first arm. Figure 3 This is a sectional view of the second arm viewed from the lateral side. Figure 4 This is a cross-sectional view of the second arm viewed from the other side laterally. Figure 5It is a magnified three-dimensional view showing the front end of the frame. Figure 6 This is a top view showing the interior of the second arm. Figure 7 This is an enlarged cross-sectional view showing the middle pulley. Figure 8 This is an enlarged cross-sectional view showing the front end of the frame. Figure 9 This is a top view used to illustrate the configuration of the through holes formed in the arm base.

[0065] It should be noted that, Figure 1 The vertical direction is the same as the vertical direction. Therefore, below, it will also be... Figure 1 The upper side is referred to as "upper" and the lower side as "lower". Furthermore, in this specification, "vertical" means not only the case of being aligned with the vertical, but also the case of being inclined relative to the vertical within the range where the effects of this invention can be achieved, for example, inclined within ±5° relative to the vertical. Similarly, in this specification, "parallel" means not only the case of being parallel to two objects, but also the case of being inclined relative to the parallel within the range where the effects of this invention can be achieved, for example, inclined within ±5° relative to the parallel.

[0066] Figure 1 The robot system 100 shown has a robot 1 and a control device 9 for controlling the drive of the robot 1.

[0067] Control device 9

[0068] like Figure 1 As shown, the control device 9 includes, for example, a control board 91 and a power supply board 92. However, it is not limited to this, and the control board 91 and the power supply board 92 may also be a single board.

[0069] The control board 91 controls the overall drive of each part of the robot 1. The control board 91 includes a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). Furthermore, the CPU reads and executes programs and data stored in the ROM to achieve the aforementioned functions. In addition, the control board 91 is electrically connected to a host computer (not shown) and controls the drive of each part of the robot 1 based on instructions from the host computer. However, it is not limited to this; the circuitry of the control board 91 may also be divided into multiple boards.

[0070] The power supply board 92 supplies power to the control board 91. The power supply board 92 includes a conversion circuit that converts externally supplied power into a predetermined value and supplies it to the control board 91. The conversion circuit varies depending on the configuration of the robot 1; however, examples include AC / DC conversion circuits that convert alternating current (AC) signals to direct current (DC) signals, boost circuits that convert the voltage level of signals, and buck circuits. However, it is not limited to these examples, and the circuitry of the power supply board 92 may be divided into multiple boards.

[0071] However, the configuration of the control device 9 is not particularly limited as long as it can control the drive of the robot 1. Furthermore, in this embodiment, the control device 9 is disposed within the base 10 of the robot 1, but its placement is not particularly limited. For example, the control device 9 may be disposed outside the base 10. In this case, the robot 1 and the control device 9 may be connected via cable or wirelessly.

[0072] Robot 1

[0073] Robot 1 is a horizontal articulated robot (SCARA robot). For example... Figure 1 As shown, robot 1 has: a base 10 fixed to the ground, etc.; a first arm 11 rotatably connected to the base 10; a second arm 12 rotatably connected to the first arm 11; a working head 13 disposed on the second arm 12; and a pipe 14 connecting the base 10 and the second arm 12.

[0074] like Figure 2 As shown, the first arm 11 is connected to the base 10 at its base end and rotates relative to the base 10 about a first rotation axis J1 along the vertical direction.

[0075] like Figure 3 and Figure 4 As shown, the second arm 12 is connected to the first arm 11 at its base end and rotates relative to the first arm 11 about a second rotation axis J2 parallel to the first rotation axis J1. Furthermore, the second arm 12 has a rigid arm base 121 connected to the first arm 11, a frame 122 fixed to the arm base 121, and a cover 123 covering the arm base 121 from the frame 122. For example, the arm base 121 and frame 122 are made of a lightweight and rigid metal material such as aluminum, and the cover 123 is made of a lightweight resin material.

[0076] Furthermore, frame 122 is a cantilever beam, with its base fixed to arm base 121 and its front end being a free end separate from arm base 121. This frame 122 is connected to pipe 14. Additionally, a connector 181 and a brake release button 17 for releasing the brake 243 (described later) are disposed on frame 122. The connector 181 and brake release button 17 are not covered by cover 123 but are exposed outside the second arm 12. Figure 1 As shown, a connector 182, which is paired with connector 181, is disposed on the back side of the base 10. The connectors 181 and 182 are connected to each other by wiring 31.

[0077] Furthermore, a lens 85 is disposed on the frame 122, which emits light when incident with light L from the light-emitting element 82 described later. Moreover, the lens 85 is not covered by the cover 123, but is exposed outside the second arm 12.

[0078] In addition, such as Figure 6 As shown, the front end of frame 122 is supported on arm base 121 via a pair of support members 41, 42. As previously mentioned, frame 122 is a cantilever beam, therefore, the front end is prone to vertical deflection. Thus, for example, due to stresses applied when the user inserts the connector 181, presses the brake release button 17, or places the wiring and devices connected to connector 181 onto frame 122, there is a possibility of plastic deformation of frame 122. Therefore, by supporting the front end of frame 122 with a pair of support members 41, 42, deformation of frame 122 can be effectively suppressed.

[0079] like Figure 1 As shown, pipe 14 is a tubular component disposed outside the first arm 11, directly connecting the base 10 and the second arm 12 without passing through the first arm 11. Furthermore, as... Figures 2 to 4 As shown, the base end of the conduit 14 is connected to the base 10, and the front end is connected to the second arm 12. It has a base end opening 141 facing into the base 10 and a front end opening 142 facing into the second arm 12. Thus, the base 10 and the second arm 12 are connected via the conduit 14. Furthermore, multiple wires 31 are wound through the conduit 14 to the base 10 and the second arm 12, and like the aforementioned connectors 181 and 182, electronic components disposed on the second arm 12 are electrically connected to electronic components disposed on the base 10 via these wires 31. Additionally, the wires 31, for example, pass through the gap between motors 231 and 241 and are wound to a position further forward than motors 231 and 241.

[0080] like Figure 3 and Figure 4As shown, the working head 13 is positioned at the front end of the second arm 12. Furthermore, the working head 13 has a spline nut 131 and a ball screw nut 132 arranged coaxially in a vertical direction, and a spline shaft 133 inserted into the spline nut 131 and the ball screw nut 132. In this working head 13, when the spline nut 131 is rotated, the spline shaft 133 rotates about its central axis and is parallel to a third rotation axis J3, and moves linearly (up and down) along the third rotation axis J3. When the ball screw nut 132 is rotated, the spline shaft 133 moves linearly along the third rotation axis J3. When both the spline nut 131 and the ball screw nut 132 are rotated, the spline shaft 133 rotates about the third rotation axis J3. Additionally, although not shown, an end effector corresponding to the operation is mounted at the lower end of the spline shaft 133.

[0081] In addition, such as Figure 2 and Figure 3 As shown, robot 1 has: a first arm drive mechanism 21 that causes the first arm 11 to rotate relative to the base 10 about a first rotation axis J1; and a second arm drive mechanism 22 that causes the second arm 12 to rotate relative to the first arm 11 about a second rotation axis J2.

[0082] like Figure 2 As shown, the first arm drive mechanism 21 includes a reducer 211 that rotatably connects the base 10 and the first arm 11, and an encoder-integrated motor 212 disposed within the base 10. The motor 212 is a servo motor, specifically a three-phase motor driven by three-phase AC, and is fixed to the base 10. The reducer 211 is a wave gear device, with a rigid gear 211a fixed to the base 10 and a flexible gear 211b fixed to the first arm 11. Furthermore, the rotation shaft of the motor 212 is fixed to a wave generator 211c. Therefore, the wave generator 211c and the motor 212 rotate together, and the flexible gear 211b rotates relative to the rotation of the wave generator 211c at a predetermined reduction ratio. As a result, the first arm 11 rotates relative to the base 10 about a first rotation axis J1. However, the configuration of the first arm drive mechanism 21 is not particularly limited.

[0083] The second arm drive mechanism 22 has the same configuration as the first arm drive mechanism 21. For example... Figure 3 and Figure 4As shown, the second arm drive mechanism 22 includes a reducer 221 that rotatably connects the first arm 11 and the second arm 12, and an encoder-integrated motor 222 disposed within the second arm 12. The motor 222 is a servo motor, particularly a three-phase motor driven by three-phase AC, and is fixed to the arm base 121. The reducer 221 is a wave gear device, with a rigid gear 221a fixed to the arm base 121 and a flexible gear 221b fixed to the first arm 11. Furthermore, the rotation shaft of the motor 222 is fixed to a wave generator 221c. Therefore, the wave generator 221c and the motor 222 rotate together, and the flexible gear 221b rotates relative to the rotation of the wave generator 221c at a predetermined reduction ratio. As a result, the second arm 12 rotates relative to the first arm 11 about a second rotation axis J2. However, the configuration of the second arm drive mechanism 22 is not particularly limited.

[0084] In addition, such as Figure 3 , Figure 4 and Figure 6 As shown, robot 1 has: a first spline shaft drive mechanism 23, which rotates spline nut 131 and rotates and linearly moves spline shaft 133; and a second spline shaft drive mechanism 24, which rotates ball screw nut 132 and linearly moves spline shaft 133.

[0085] like Figure 3 and Figure 6 As shown, the spline shaft first drive mechanism 23 has an encoder-integrated first motor 231 disposed in the second arm 12, and a reduction mechanism 232 that transmits the rotation of the first motor 231 to the spline nut 131. The first motor 231 is a servo motor, particularly a three-phase motor driven by three-phase AC, and is fixed to the arm base 121.

[0086] The reduction mechanism 232 includes: a first pulley 51 fixed to the rotating shaft of the first motor 231; a second pulley 52 fixed to the spline nut 131; a support member 59 fixed to the arm base 121; an intermediate pulley 54 supported by the support member 59 via bearings 501 and 502 (described later) and rotating relative to the arm base 121 about a fourth rotating shaft J4 in the vertical direction; a first belt 55 wrapped around the first pulley 51 and the intermediate pulley 54; and a second belt 56 wrapped around the intermediate pulley 54 and the second pulley 52.

[0087] In addition, such as Figure 7As shown, the intermediate pulley 54 includes: a first intermediate pulley 541; a second intermediate pulley 542 located below the first intermediate pulley 541, i.e., on the side of the arm base 121, and having a smaller diameter than the first intermediate pulley 541; and a shaft portion 543 disposed along the fourth rotation axis J4, connecting the first intermediate pulley 541 and the second intermediate pulley 542. It should be noted that in this embodiment, the second intermediate pulley 542 and the shaft portion 543 are integrally formed, and the shaft portion 543 and the first intermediate pulley 541 are fixed. However, this is not limited to this configuration. It is also possible that the first intermediate pulley 541 and the shaft portion 543 are integrally formed, and the shaft portion 543 and the second intermediate pulley 542 are fixed. Alternatively, it is possible that the first intermediate pulley 541, the second intermediate pulley 542, and the shaft portion 543 are separately formed and fixed to each other.

[0088] Furthermore, the lower end of the shaft portion 543 protrudes downward toward the lower side of the second intermediate pulley 542. Additionally, the intermediate pulley 54 is rotatably supported at two points on the shaft portion 543 by a bearing 501 (serving as a first bearing) and a bearing 502 (serving as a second bearing). The bearing 501 is located between the first intermediate pulley 541 and the second intermediate pulley 542, and the bearing 502 is located below the second intermediate pulley 542.

[0089] The support member 59 includes: a first retaining portion 591, which retains the portion between the first intermediate pulley 541 and the second intermediate pulley 542 of the shaft portion 543 via a bearing 501; a second retaining portion 592, which retains the lower portion of the second intermediate pulley 542 of the shaft portion 543 via a bearing 502; and a connecting portion 593, which connects the first retaining portion 591 and the second retaining portion 592. It should be noted that in this embodiment, the second retaining portion 592 and the connecting portion 593 are integrally formed, and the connecting portion 593 and the first retaining portion 591 are fixed by screws. However, this is not a limitation; the first retaining portion 591 and the connecting portion 593 may be integrally formed, and the connecting portion 593 and the second retaining portion 592 may be fixed by screws, or the first retaining portion 591, the second retaining portion 592, and the connecting portion 593 may be formed separately from each other. Furthermore, the support member 59 and the arm base 121 may also be fixed by screws. In this case, for example, through holes can be formed in the first retaining part 591, the second retaining part 592, and the connecting part 593, and screws passing through the through holes can be fastened to the arm base 121. As a result, the fixing operation between the support member 59 and the arm base 121 can be easily performed.

[0090] Furthermore, the first intermediate pulley 541 is aligned with the first pulley 51 at the same height. The first intermediate pulley 541 has a larger diameter than the first pulley 51, and a first belt 55 is wound around both the first pulley 51 and the first intermediate pulley 541. These first pulleys 51, the first intermediate pulley 541, and the first belt 55 constitute the first reduction mechanism 232a in the front section. On the other hand, the second intermediate pulley 542 is aligned with the second pulley 52 at the same height. The second intermediate pulley 542 has a smaller diameter than the second pulley 52, and a second belt 56 is wound around both the second intermediate pulley 542 and the second pulley 52. ​​These second intermediate pulleys 542, the second pulley 52, and the second belt 56 constitute the second reduction mechanism 232b in the rear section.

[0091] In this configuration, the rotation of the first motor 231 is transmitted to the first intermediate pulley 541 via the first pulley 51 and the first belt 55. The first intermediate pulley 541 and the second intermediate pulley 542 rotate together around the fourth rotation axis J4. Furthermore, the rotation of the second intermediate pulley 542 is transmitted to the second pulley 52 via the second belt 56. The second pulley 52 and the spline nut 131 rotate together around the third rotation axis J3. Thus, the spline shaft 133 rotates around the third rotation axis J3 and moves linearly along the third rotation axis J3. That is, it rotates at least once. Because the reduction mechanism 232 includes the first reduction mechanism 232a and the second reduction mechanism 232b, the rotation of the first motor 231 can be reduced in two stages, allowing the spline nut 131 to rotate with a greater torque.

[0092] Here, as Figure 7 As shown, the first intermediate pulley 541 has a cylindrical belt mounting portion 541a around which the first belt 55 is wrapped, and a connecting portion 541b located inside the belt mounting portion 541a and connecting the shaft portion 543 and the belt mounting portion 541a. Furthermore, the connecting portion 541b is thin-walled, and its thickness, i.e., its length along the direction of the fourth rotation axis J4, is smaller than that of the belt mounting portion 541a. Therefore, the intermediate pulley 54 can be lightweight. Moreover, a weight-reducing portion 541c, consisting of a through hole extending through the thickness direction, is formed in the connecting portion 541b. Therefore, the intermediate pulley 54 can be further lightweighted. In particular, the first intermediate pulley 541 has a larger diameter than the second intermediate pulley 542. Therefore, the lightweighting effect of the intermediate pulley 54 resulting from the thinning of the connecting portion 541b and the formation of the weight-reducing portion 541c is greater.

[0093] Furthermore, when viewed from above along the fourth rotation axis J4, the weight-reducing part 541c overlaps with the screws of the fixed connecting part 593 and the first retaining part 591. Therefore, tools such as screwdrivers can be inserted into the weight-reducing part 541c and the screws tightened, making it easy to fix the connecting part 593 and the first retaining part 591.

[0094] It should be noted that in this embodiment, the two fan-shaped weight-reducing portions 541c are symmetrically arranged with respect to the fourth rotation axis J4; however, the shape and number of the weight-reducing portions 541c are not particularly limited. Furthermore, the same weight-reducing portion as the first intermediate pulley 541 can be formed on the second intermediate pulley 542. This allows for further weight reduction of the intermediate pulley 54. Alternatively, the weight-reducing portions 541c can be omitted.

[0095] like Figure 4 and Figure 6 As shown, the splined shaft second drive mechanism 24 includes an encoder-integrated second motor 241 disposed within the second arm 12, a reduction mechanism 242 that transmits the rotation of the second motor 241 to the ball screw nut 132, and a brake 243 for the second motor 241. The second motor 241 is a servo motor, particularly a three-phase motor driven by three-phase AC, and is fixed to the arm base 121.

[0096] The reduction mechanism 242 includes a third pulley 242a fixed to the rotating shaft of the second motor 241, a fourth pulley 242b fixed to the ball screw nut 132, and a third belt 242c wound around the third pulley 242a and the fourth pulley 242b. In this configuration, the rotation of the second motor 241 is transmitted to the fourth pulley 242b via the third pulley 242a and the third belt 242c. The fourth pulley 242b and the ball screw nut 132 rotate integrally around the third rotating shaft J3. As a result, the spline shaft 133 moves linearly along the third rotating shaft J3. Thus, by using the reduction mechanism 242, the rotation of the second motor 241 can be reduced, and the ball screw nut 132 can be rotated with a sufficiently large torque.

[0097] It should be noted that, as Figure 3 As shown, when viewed from above in a direction orthogonal to the fourth rotation axis J4, the third belt 242c is located between the first belt 55 and the second belt 56. That is, the first belt 55 is located above the third belt 242c, and the second belt 56 is located below the third belt 242c. With this configuration, when viewed from above along the second rotation axis J2, the third belt 242c can intersect with the first and second belts 55 and 56. Therefore, the degree of freedom in the arrangement of the intermediate pulley 54 is increased. However, the configuration of the spline shaft second drive mechanism 24 is not particularly limited. For example, the third belt 242c can also be located above the first belt 55, that is, higher than the intermediate pulley 54.

[0098] like Figure 4As shown, brake 243 is an electromagnetic brake mounted on the second motor 241, having a pair of plates 243a and 243b arranged opposite each other. One plate 243a is fixed to the second motor 241, and the other plate 243b is fixed to the rotating shaft of the second motor 241 and rotates with the rotating shaft. Furthermore, by controlling the on / off state of the energized system, a braking state is switched between the plates 243a and 243b being in contact to restrict the rotation of the rotating shaft, and a braking release state is switched between the plates 243a and 243b being separated to allow the rotation of the rotating shaft. In particular, the brake 243 of this embodiment is a non-energized electromagnetic brake, which is in a braking release state when energized (ON) and in a braking state when energized (OFF). However, the configuration of brake 243 is not particularly limited.

[0099] In addition, such as Figure 5 and Figure 8 As shown, the brake control board 8, which controls the brake 243, is fixed to the frame 122. The brake control board 8 is electrically connected to the control board 91 via wiring 31. Furthermore, the brake control board 8 is electrically connected to the brake 243 via wiring 32 and to the brake release button 17 via wiring 33. This brake control board 8 controls the actuation of the brake 243 based on commands from the control board 91, switching between braking and brake release states. Additionally, the brake control board 8 controls the actuation of the brake 243 based on the operation of the brake release button 17, switching between braking and brake release states.

[0100] In addition, such as Figure 8 As shown, robot 1 has a light-emitting element 82 mounted on the brake control board 8. The light-emitting element 82 is, for example, an LED (Light Emitting Diode). The light L emitted from the light-emitting element 82 is diffusely reflected upwards by the frame 122 and then incident on the lens 85. As a result, the lens 85 emits light. Therefore, by controlling the drive of the light-emitting element 82, switching the lens 85 on / flickering / off, or switching the light emission color of the lens 85, various information can be communicated to the user through the lens 85.

[0101] During the period when power is supplied to motors 212, 222, 231, and 241, i.e., when the power supply to robot 1 is turned on, the brake control board 8 emits light L of a predetermined color from the light-emitting element 82, causing lens 85 to emit light. It should be noted that this state will be referred to below as the first emitting state. This allows for easy notification to the user that the power supply to robot 1 has been turned on. Furthermore, when the brake release button 17 is pressed and brake 243 is in the brake release state, the brake control board 8 emits light L of a different color from light L from the light-emitting element 82, causing lens 85 to emit light. It should be noted that this state will be referred to below as the second emitting state. This allows for easy notification to the user that brake 243 is in the brake release state. However, the notification method is not particularly limited; for example, the first emitting state can be set to illuminated and the second emitting state to off, or the first emitting state can be set to illuminated and the second emitting state to flashing.

[0102] The brake control board 8 described above includes a CPU (Central Processing Unit) and a ROM (Read Only Memory). Furthermore, the CPU reads and executes programs and data stored in the ROM to achieve the aforementioned functions.

[0103] In addition, such as Figure 3 , Figure 4 and Figure 6 As shown, robot 1 has a mounting component 16 disposed within the second arm 12 and carrying an inertial sensor module 6, which measures the inertia of the second arm 12. The mounting component 16 is fixed to the arm base 121 via a plurality of supports 165 and is located above the second belt 56 and the third belt 242c.

[0104] The inertial sensor module 6 includes: a substrate 61 fixed to the mounting member 16 via a plurality of spacers 164; and an angular velocity sensor 62 mounted on the substrate 61, which detects the angular velocity of the second arm 12 about a vertical axis. Furthermore, the angular velocity sensor 62 includes a package, and angular velocity sensor elements and circuit elements housed within the package. The angular velocity sensor element is, for example, a crystal oscillator, having: a driving wrist that drives vibration by applying a driving signal; and a detection wrist that detects vibration by applying a Coriolis force generated by the angular velocity and outputs a signal of a corresponding magnitude. Furthermore, the circuit elements include, for example, a driving circuit that applies a driving signal to cause the driving wrist of the crystal oscillator to vibrate; and a detection circuit that detects the angular velocity based on the signal output from the detection wrist. When viewed from above along the direction of the second rotation axis J2, the inertial sensor module 6 is positioned overlapping with the imaginary central axis A described later. However, this is not a limitation; the inertial sensor module 6 may also be positioned not overlapping with the imaginary central axis A.

[0105] Furthermore, a control circuit (not shown) is formed on the substrate 61, which controls the drive of the angular velocity sensor 62 based on instructions from the control substrate 91. The control circuit includes a CPU (Central Processing Unit) and a ROM (Read Only Memory), etc., and reads and executes programs and data stored in the ROM through the CPU to achieve the above-mentioned functions.

[0106] However, the inertial sensor module 6 is not particularly limited. For example, in this embodiment, the inertial sensor is an angular velocity sensor that detects the angular velocity of the second arm 12, but it is not limited to this. For example, it could also be an acceleration sensor that detects the acceleration of the second arm 12. Furthermore, it could also be a composite sensor capable of detecting both angular velocity and acceleration. In addition, in this embodiment, the angular velocity sensor element is a crystal oscillator, but it is not limited to this. For example, it could also be a silicon MEMS that detects angular velocity based on the change in electrostatic capacitance between the movable electrode and the fixed electrode.

[0107] Here, as Figure 3 and Figure 4As shown, a through hole 123a for inserting a splined shaft 133 is formed on the cover 123 of the second arm 12. Furthermore, because the splined shaft 133 moves vertically up and down, airflow is generated between the through hole 123a and the through hole 121a formed on the arm base 121 (described later). When this airflow impacts the inertial sensor module 6, the inertial sensor module 6 vibrates, potentially leading to a decrease in angular velocity detection accuracy. Therefore, a guide wall 123b is formed between the splined shaft 133 of the cover 123 and the inertial sensor module 6 to guide the airflow. This makes it difficult for the airflow to impact the inertial sensor module 6, effectively suppressing the decrease in the angular velocity detection accuracy of the inertial sensor module 6.

[0108] The overall structure of robot 1 has been described above. The configuration of each part included in the first spline shaft drive mechanism 23 and the second spline shaft drive mechanism 24 will now be described. It should be noted that, when viewed from above along the direction of the second rotation axis J2, the straight line intersecting the second rotation axis J2 and the third rotation axis J3 will also be referred to as the imaginary central axis A of the second arm 12.

[0109] like Figure 9 As shown, when viewed from above along the second rotation axis J2, a first motor 231 and an intermediate pulley 54 of the spline shaft first drive mechanism 23 are arranged on one side of the imaginary central axis A, and a second motor 241 of the spline shaft second drive mechanism 24 is arranged on the other side of the imaginary central axis A. It should be noted that "the first motor 231 and the intermediate pulley 54 are arranged on one side of the imaginary central axis A" means that the central axis of the rotation shaft of the first motor 231 and the fourth rotation shaft J4 are located on one side of the imaginary central axis A. Therefore, as long as the above positional relationship is satisfied, the first motor 231 and the intermediate pulley 54 can either have their entire area located on one side of the imaginary central axis A, or they can be respectively arranged to cover both sides of the imaginary central axis A. Similarly, "the second motor 241 is arranged on the other side of the imaginary central axis A" means that the central axis of the rotation shaft of the second motor 241 is located on the other side of the imaginary central axis A. Therefore, as long as the above positional relationship is satisfied, the entire area of ​​the second motor 241 can be located on the other side of the imaginary central axis A, or it can be set to cover both sides of the imaginary central axis A.

[0110] In this way, by arranging the first and second motors 231 and 241, which are weights, on opposite sides of the imaginary central axis A, the weight difference between one side and the other side of the imaginary central axis A can be reduced compared to arranging them on the same side, thus preventing the deterioration of the weight balance of the second arm 12. However, in the spline shaft first drive mechanism 23 and the spline shaft second drive mechanism 24, only the intermediate pulley 54 of the spline shaft first drive mechanism 23 is arranged on one side of the imaginary central axis A. Consequently, one side of the imaginary central axis A becomes heavier, and the weight balance of the second arm 12 deteriorates. Therefore, in the robot 1, a through hole 121a is formed on the arm base 121 to suppress the deterioration of the weight balance caused by the intermediate pulley 54. The through hole 121a will be described in detail below.

[0111] like Figure 9 As shown, when viewed from above along the direction of the second rotation axis J2, the through hole 121a is configured to be biased towards one side of the imaginary central axis A. It should be noted that "the through hole 121a is configured to be biased towards one side of the imaginary central axis A" means that the center of the through hole 121a is located on one side of the imaginary central axis A; in other words, it means that the area on one side of the imaginary central axis A is larger than the area on the other side. Therefore, as long as the above positional relationship is satisfied, the through hole 121a can be configured with its entire area on one side of the imaginary central axis A, or it can be configured to cover both sides of the imaginary central axis A. However, in this embodiment, the entire area of ​​the through hole 121a is configured on one side of the imaginary central axis A. By forming such a through hole 121a, at least a portion of the weight increase caused by the intermediate pulley 54 can be eliminated on one side of the imaginary central axis A due to the weight reduction brought about by the through hole 121a. Therefore, by forming the through hole 121a, the deterioration of the weight balance of the second arm 12 can be effectively suppressed. In other words, the difference between the weight on one side and the weight on the other side of the imaginary central axis A can be minimized. As a result, the driving accuracy of the second arm 12 is improved.

[0112] Furthermore, when viewed from above along the direction of the second rotation axis J2, the through hole 121a is located closer to the third rotation axis J3 than the fourth rotation axis J4, that is, it is located on the front end side of the second arm 12. With this configuration, the weight of the front end of the second arm 12 can be reduced through the through hole 121a, and thus the moment of inertia of the second arm 12 can be reduced.

[0113] Furthermore, when viewed from above along the second rotation axis J2, the through hole 121a overlaps with the intermediate pulley 54. With this configuration, the intermediate pulley 54, which is the main cause of weight imbalance deterioration, and the through hole 121a, which improves weight balance, can be positioned more closely together. Therefore, the deterioration of the weight balance of the second arm 12 can be effectively suppressed. However, this is not a limitation; it is also possible for the through hole 121a and the intermediate pulley 54 not to overlap when viewed from above along the second rotation axis J2.

[0114] In addition, such as Figure 9 As shown, the first intermediate pulley 541 is positioned higher than the third belt 242c, and when viewed from above along the second rotation axis J2, the first intermediate pulley 541 overlaps with the third belt 242c. Thus, when viewed from above along the second rotation axis J2, because the intermediate pulley 541 overlaps with the third belt 242c, it can be positioned as close as possible to the imaginary central axis A. Therefore, the degree of weight imbalance deterioration caused by the intermediate pulley 54 can be minimized, and correspondingly, the through hole 121a used to improve weight balance can be reduced in size. Since the size of the through hole 121a that can be formed in the arm base 121 is limited, a smaller through hole 121a is sufficient, making it easier to form a through hole 121a of a size that corresponds to the weight imbalance deterioration caused by the intermediate pulley 54, and thus more effectively suppressing the weight imbalance deterioration of the second arm 12. Furthermore, since the through hole 121a only needs to be smaller, the reduction in rigidity of the arm base 121 can also be suppressed. However, it is not limited to this. It is also possible that when viewed from above along the direction of the second rotation axis J2, the intermediate pulley 54 and the third belt 242c do not overlap.

[0115] In addition, such as Figure 9As shown, when viewed from above along the direction of the second rotation axis J2, the intermediate pulley 54 overlaps with the imaginary central axis A. By forming it in this way, the intermediate pulley 54 can be positioned as close as possible to the imaginary central axis A. Therefore, the degree of weight imbalance deterioration caused by the intermediate pulley 54 can be minimized, and correspondingly, the through-hole 121a used for weight balance improvement can be reduced in size. Since the size of the through-hole 121a that can be formed in the arm base 121 is limited, the through-hole 121a only needs to be small, making it easier to form a through-hole 121a of a size that corresponds to the weight imbalance deterioration caused by the intermediate pulley 54, thus more effectively suppressing the weight imbalance deterioration of the second arm 12. Furthermore, since the through-hole 121a only needs to be small, the reduction in rigidity of the arm base 121 can also be suppressed. In particular, in this embodiment, as described above, when viewed from a direction orthogonal to the fourth rotation axis J4, the third belt 242c is located between the first belt 55 and the second belt 56, thus allowing the third belt 242c to intersect with the first and second belts 55 and 56. Therefore, the configuration freedom of the intermediate pulley 54 is increased, making it easier to position the intermediate pulley 54 close to the imaginary central axis A. However, this is not a limitation; it is also permissible for the intermediate pulley 54 to not overlap with the imaginary central axis A when viewed from a direction along the second rotation axis J2.

[0116] Thus, in robot 1, when viewed from above along the second rotation axis J2, the intermediate pulley 54 is configured to overlap with the third belt 242c and the imaginary central axis A, thereby minimizing the degree of weight imbalance deterioration caused by the intermediate pulley 54. Based on this, in this embodiment, as described above, a weight-reducing portion 541c is formed on the first intermediate pulley 541, thereby achieving weight reduction of the intermediate pulley 54. Furthermore, the support member 59 supporting the intermediate pulley 54 is configured to support both the upper and lower sides of the lower-positioned second intermediate pulley 542 among the vertically arranged first and second intermediate pulleys 541 and 542, thus lowering the center of gravity of the support member 59. Through these configurations, the degree of weight imbalance deterioration caused by the intermediate pulley 54 is minimized. Therefore, in robot 1, not only the configuration of the intermediate pulley 54, but also the weight reduction of the intermediate pulley 54 itself and the configuration of the support member 59 supporting the intermediate pulley 54 are studied, thereby minimizing the degree of weight imbalance deterioration caused by the intermediate pulley 54.

[0117] In addition, such as Figure 9 As shown, in robot 1, when viewed from above along the direction of the second rotation axis J2, the mounting member 16 overlaps with the imaginary central axis A. By configuring the mounting member 16 in this way, it is possible to suppress the deterioration of the weight balance of the second arm 12 caused by the mounting member 16.

[0118] The robot system 100 has been described above. As previously mentioned, such a robot system 100 includes a robot 1 comprising: a base 10; a first arm 11 connected to the base 10 and rotating relative to the base 10 about a first rotation axis J1; a second arm 12 having an arm base 121 connected to the first arm 11, the second arm 12 rotating relative to the first arm 11 about a second rotation axis J2 parallel to the first rotation axis J1; and a working head 13 disposed on the second arm 12, the working head 13 having a splined shaft 133 along a third rotation axis J3 parallel to the first rotation axis J1, and a splined nut 131 mounted on the splined shaft 133 and a roller. The ball screw nut 132 rotates the spline shaft 133 at least around the third rotation axis J3 when the spline nut 131 is rotated, and the spline shaft 133 moves linearly along the third rotation axis J3 when the ball screw nut 132 is rotated; and the first drive mechanism 23 and the second drive mechanism 24 of the spline shaft are disposed in the second arm 12. The first drive mechanism 23 rotates the spline nut 131 and causes the spline shaft 133 to rotate at least around the third rotation axis J3, and the second drive mechanism 24 rotates the ball screw nut 132 and causes the spline shaft 133 to move linearly along the third rotation axis J3. Furthermore, the first drive mechanism 23 of the splined shaft includes: a first motor 231 fixed to the arm base 121; a first pulley 51 fixed to the rotating shaft of the first motor 231; a second pulley 52 fixed to the splined nut 131; an intermediate pulley 54 rotating relative to the arm base 121 about a fourth rotating shaft J4 parallel to the first rotating shaft J1; a first belt 55 wound around the first pulley 51 and the intermediate pulley 54; and a second belt 56 wound around the intermediate pulley 54 and the second pulley 52. ​​Furthermore, the second drive mechanism 24 of the splined shaft includes: a second motor 241 fixed to the arm base 121; a third pulley 242a fixed to the rotating shaft of the second motor 241; a fourth pulley 242b fixed to the ball screw nut 132; and a third belt 242c wound around the third pulley 242a and the fourth pulley 242b. Furthermore, when viewed from above along the second rotation axis J2, with the straight line intersecting the second rotation axis J2 and the third rotation axis J3 designated as the imaginary central axis A of the second arm 12, the first motor 231 and the intermediate pulley 54 are located on one side of the imaginary central axis A, and the second motor 241 is located on the other side of the imaginary central axis A. Additionally, a through hole 121a is formed on the arm base 121, extending through the arm base 121 in the direction along the second rotation axis J2. The through hole 121a is positioned on one side of the imaginary central axis A, that is, on the side biased towards the intermediate pulley 54. With this configuration, at least a portion of the weight increase caused by the intermediate pulley 54 can be eliminated on one side of the imaginary central axis A through the weight reduction brought about by the through hole 121a. Therefore, by forming the through hole 121a, the deterioration of the weight balance of the second arm 12 can be effectively suppressed.In other words, the difference between the weight on one side and the weight on the other side of the imaginary central axis A can be minimized. As a result, the driving accuracy of the second arm 12 is improved.

[0119] Furthermore, as mentioned earlier, the third rotation axis J3 is located closer to the front end of the second arm 12 than the fourth rotation axis J4. When viewed from above along the direction of the second rotation axis J2, the through hole 121a is located closer to the third rotation axis J3 than the fourth rotation axis J4. With this configuration, the weight of the front end of the second arm 12 can be reduced, and the moment of inertia of the second arm 12 can be decreased.

[0120] Furthermore, as mentioned earlier, when viewed from above along the direction of the second rotation axis J2, the through hole 121a overlaps with the intermediate pulley 54. With this configuration, the intermediate pulley 54, which is a major cause of weight imbalance deterioration, can be positioned closer to the through hole 121a used for weight balance improvement. Therefore, the deterioration of the weight balance of the second arm 12 can be effectively suppressed.

[0121] Furthermore, as mentioned earlier, when viewed from above along the direction of the second rotation axis J2, the intermediate pulley 54 overlaps with the third belt 242c. By forming it in this configuration, the intermediate pulley 54 can be positioned as close as possible to the imaginary central axis A. Therefore, the degree of weight imbalance deterioration caused by the intermediate pulley 54 can be minimized, and correspondingly, the through-hole 121a used to improve weight balance can be reduced in size. Since the size of the through-hole 121a that can be formed in the arm base 121 is limited, the through-hole 121a only needs to be small, making it easier to form a through-hole 121a of a size that corresponds to the weight imbalance deterioration caused by the intermediate pulley 54, thus more effectively suppressing the weight imbalance deterioration of the second arm 12. Furthermore, since the through-hole 121a only needs to be small, the reduction in rigidity of the arm base 121 can also be suppressed.

[0122] Furthermore, as mentioned earlier, when viewed from above along the direction of the second rotation axis J2, the intermediate pulley 54 overlaps with the imaginary central axis A. By forming it in this way, the intermediate pulley 54 can be positioned as close as possible to the imaginary central axis A. Therefore, the degree of weight imbalance deterioration caused by the intermediate pulley 54 can be minimized, and correspondingly, the through-hole 121a used to improve weight balance can be reduced in size. Since the size of the through-hole 121a that can be formed in the arm base 121 is limited, a smaller through-hole 121a is sufficient, making it easier to form a through-hole 121a of a size that corresponds to the weight imbalance deterioration caused by the intermediate pulley 54, thus more effectively suppressing the weight imbalance deterioration of the second arm 12. Furthermore, since the through-hole 121a only needs to be smaller, the reduction in rigidity of the arm base 121 can also be suppressed.

[0123] Furthermore, as previously described, the intermediate pulley 54 includes: a shaft portion 543 extending along a fourth rotation axis J4; a first intermediate pulley 541 disposed on the shaft portion 543 and wound with a first belt 55; and a second intermediate pulley 542 disposed on the shaft portion 543, the second intermediate pulley 542 being located closer to the arm base 121 than the first intermediate pulley 541, and wound with a second belt 56. Additionally, the robot 1 has a support member 59 fixed to the arm base 121, which holds the portion of the shaft portion 543 between the first intermediate pulley 541 and the second intermediate pulley 542 via a bearing 501 serving as a first bearing, and holds the portion of the shaft portion 543 closer to the arm base 121 than the second intermediate pulley 542 via a bearing 502 serving as a second bearing. With this configuration, the center of gravity of the support member 59 can be kept low. Therefore, the degree of weight imbalance deterioration caused by the intermediate pulley 54 can be minimized.

[0124] Furthermore, as mentioned earlier, when viewed from above in a direction orthogonal to the fourth rotation axis J4, the third belt 242c is located between the first belt 55 and the second belt 56. With this configuration, when viewed from above along the second rotation axis J2, the third belt 242c can intersect with the first and second belts 55 and 56. Therefore, the degree of freedom in the arrangement of the intermediate pulley 54 is increased, making it easier to position the intermediate pulley 54 towards the imaginary central axis A.

[0125] Furthermore, as mentioned above, the diameter of the first intermediate pulley 541 is larger than the diameter of the second intermediate pulley 542, and a weight-reducing portion 541c is formed on the first intermediate pulley 541, extending through the first intermediate pulley 541 in the direction along the fourth rotation axis J4. With this configuration, the intermediate pulley 54 can be made lighter, and the degree of deterioration in weight balance caused by the intermediate pulley 54 can be minimized.

[0126] Furthermore, as previously described, robot 1 has a mounting component 16 disposed on the second arm 12, which houses an inertial sensor module 6 for measuring the inertia of the second arm 12. Additionally, when viewed from above along the second rotation axis J2, the mounting component 16 overlaps with the imaginary central axis A. This configuration helps to suppress the deterioration of the weight balance of the second arm 12 caused by the mounting component 16.

[0127] Furthermore, as previously described, the robot system 100 includes a robot 1 and a control device 9 for controlling the drive of the robot 1. Additionally, the robot 1 includes: a base 10; a first arm 11 connected to the base 10 and rotating relative to the base 10 about a first rotation axis J1; a second arm 12 having an arm base 121 connected to the first arm 11, the second arm 12 rotating relative to the first arm 11 about a second rotation axis J2 parallel to the first rotation axis J1; and a working head 13 disposed on the second arm 12, the working head 13 having a splined shaft 133 along a third rotation axis J3 parallel to the first rotation axis J1, and a splined nut 131 and a ball screw nut 132 mounted on the splined shaft 133. When the spline nut 131 is rotated, the spline shaft 133 rotates at least around the third rotation axis J3. When the ball screw nut 132 is rotated, the spline shaft 133 moves linearly along the third rotation axis J3. The first drive mechanism 23 and the second drive mechanism 24 of the spline shaft are disposed in the second arm 12. The first drive mechanism 23 rotates the spline nut 131, causing the spline shaft 133 to rotate at least around the third rotation axis J3. The second drive mechanism 24 rotates the ball screw nut 132, causing the spline shaft 133 to move linearly along the third rotation axis J3. Furthermore, the first drive mechanism 23 of the splined shaft includes: a first motor 231 fixed to the arm base 121; a first pulley 51 fixed to the rotating shaft of the first motor 231; a second pulley 52 fixed to the splined nut 131; an intermediate pulley 54 rotating relative to the arm base 121 about a fourth rotating shaft J4 parallel to the first rotating shaft J1; a first belt 55 wound around the first pulley 51 and the intermediate pulley 54; and a second belt 56 wound around the intermediate pulley 54 and the second pulley 52. ​​Furthermore, the second drive mechanism 24 of the splined shaft includes: a second motor 241 fixed to the arm base 121; a third pulley 242a fixed to the rotating shaft of the second motor 241; a fourth pulley 242b fixed to the ball screw nut 132; and a third belt 242c wound around the third pulley 242a and the fourth pulley 242b. Furthermore, when viewed from above along the second rotation axis J2, with the straight line intersecting the second rotation axis J2 and the third rotation axis J3 designated as the imaginary central axis A of the second arm 12, the first motor 231 and the intermediate pulley 54 are located on one side of the imaginary central axis A, and the second motor 241 is located on the other side of the imaginary central axis A. Additionally, a through hole 121a is formed on the arm base 121, extending through the arm base 121 in the direction along the second rotation axis J2. When viewed from above along the second rotation axis J2, the through hole 121a is positioned on one side of the imaginary central axis A, i.e., biased towards the side where the intermediate pulley 54 is located. With this configuration, at least a portion of the weight increase caused by the intermediate pulley 54 can be eliminated by the weight reduction brought by the through hole 121a on one side of the imaginary central axis A. Therefore, by forming the through hole 121a, the weight balance of the second arm 12 can be improved.In other words, the difference between the weight on one side and the weight on the other side of the imaginary central axis A can be minimized. As a result, the driving accuracy of the second arm 12 is improved.

[0128] Second Implementation Method

[0129] Figure 10 This is a top view showing the interior of the second arm of the robot according to the second embodiment.

[0130] The robot 1 described in this embodiment is identical to the robot 1 of the first embodiment, except for the configuration of the mounting component 16. It should be noted that in the following description, the robot 1 of this embodiment will be described primarily for its differences from the first embodiment, while identical details will be omitted. Furthermore, in the figures of this embodiment, the same reference numerals are used for configurations identical to those in the aforementioned embodiments.

[0131] like Figure 10 As shown, in the robot 1 of this embodiment, when viewed from above along the direction of the second rotation axis J2, the mounting component 16 is located on the other side of the imaginary central axis A, that is, on the side opposite to the intermediate pulley 54. It should be noted that "the mounting component 16 is located on the other side of the imaginary central axis A" means that when viewed from above along the direction of the second rotation axis J2, the center of gravity of the mounting component 16, including the inertial sensor module 6 and the isolating plate, is located on the other side of the imaginary central axis A. Therefore, as long as the above positional relationship is satisfied, either the entire area of ​​the mounting component 16 can be located on the other side of the imaginary central axis A, or it can be located on both sides of the imaginary central axis A. With this configuration, the weight increase on the other side of the imaginary central axis A caused by the mounting component 16 can offset part of the weight increase on one side of the imaginary central axis A caused by the intermediate pulley 54. Therefore, compared to the first embodiment described above, the through hole 121a can be smaller, making it easier to form.

[0132] As described above, the robot 1 of this embodiment has a mounting member 16, which is disposed on the second arm 12 and houses an inertial sensor module 6 for measuring the inertia of the second arm 12. Furthermore, when viewed from above along the second rotation axis J2, the mounting member 16 is located on the other side of the imaginary central axis A, i.e., on the side opposite to the intermediate pulley 54. With this configuration, the weight increase on the other side of the imaginary central axis A caused by the mounting member 16 can offset a portion of the weight increase on one side of the imaginary central axis A caused by the intermediate pulley 54. Therefore, compared to the first embodiment described above, the through hole 121a can be smaller and easier to form.

[0133] This second implementation method can achieve the same effect as the first implementation method described above.

[0134] The robot and robot system of this utility model have been described above based on the illustrated embodiments. However, this utility model is not limited thereto, and the configuration of each part can be replaced with any configuration having the same function. Furthermore, other arbitrary configurations can be added to this utility model. For example, in the aforementioned embodiment, robot 1 has a pipe 14, but the pipe 14 may be omitted. In this case, wiring 31 is wound around the base 10 and the second arm 12 via the first arm 11. Furthermore, in the aforementioned embodiment, robot 1 is a ground-mounted SCARA robot with the base 10 fixed to the ground, etc., but it may also be a suspended SCARA robot with the base 10 suspended from the ceiling. In this case, the base 10 is, for example, suspended from a top plate located on the upper part of a frame with frame-shaped legs.

Claims

1. A robot, characterized in that, have: abutment; The first arm is connected to the base and rotates about a first rotation axis relative to the base; The second arm has an arm base connected to the first arm, and the second arm rotates relative to the first arm about a second rotation axis parallel to the first rotation axis. The working head is disposed on the second arm. The working head has a splined shaft along a third rotation axis parallel to the first rotation axis, and a splined nut and a ball screw nut mounted on the splined shaft. When the splined nut is rotated, the splined shaft rotates around the third rotation axis. When the ball screw nut is rotated, the splined shaft moves linearly along the third rotation axis. as well as A first drive mechanism and a second drive mechanism for the spline shaft are disposed within the second arm. The first drive mechanism rotates the spline nut, causing the spline shaft to rotate about the third rotation axis. The second drive mechanism rotates the ball screw nut, causing the spline shaft to move linearly along the third rotation axis. The first drive mechanism for the splined shaft includes: a first motor fixed to the arm base; a first pulley fixed to the rotating shaft of the first motor; a second pulley fixed to the splined nut; an intermediate pulley that rotates relative to the arm base about a fourth rotating shaft parallel to the first rotating shaft; a first belt wound around the first pulley and the intermediate pulley; and a second belt wound around the intermediate pulley and the second pulley. The second drive mechanism for the splined shaft includes: a second motor fixed to the arm base; a third pulley fixed to the rotating shaft of the second motor; a fourth pulley fixed to the ball screw nut; and a third belt wound around the third and fourth pulleys. When viewed from above along the second rotation axis, with the straight line intersecting the second and third rotation axes as the imaginary central axis of the second arm, the first motor and the intermediate pulley are located on one side of the imaginary central axis, and the second motor is located on the other side of the imaginary central axis. A through hole is formed on the arm base, extending through the arm base in the direction along the second rotation axis. When viewed from above in the direction along the second rotation axis, the through hole is positioned biased toward one side of the imaginary central axis.

2. The robot according to claim 1, characterized in that, The third rotation axis is located closer to the front end of the second arm than the fourth rotation axis. When viewed from above along the direction of the second rotation axis, the through hole is located on the side of the third rotation axis that is closer to it than the fourth rotation axis.

3. The robot according to claim 1, characterized in that, When viewed from above along the direction of the second rotation axis, the through hole overlaps with the intermediate pulley.

4. The robot according to claim 1, characterized in that, When viewed from above along the second axis of rotation, the intermediate pulley overlaps with the third belt.

5. The robot according to claim 1, characterized in that, When viewed from above along the direction of the second rotation axis, the intermediate pulley overlaps with the imaginary central axis.

6. The robot according to claim 1, characterized in that, The intermediate pulley has: a shaft extending along the fourth rotation axis; a first intermediate pulley disposed on the shaft and wound with the first belt; and a second intermediate pulley disposed on the shaft, located further from the arm base than the first intermediate pulley, and wound with the second belt. The robot has a support component fixed to the arm base, which holds the portion of the shaft between the first intermediate pulley and the second intermediate pulley via a first bearing, and holds the portion of the shaft that is closer to the arm base than the second intermediate pulley via a second bearing.

7. The robot according to claim 6, characterized in that, When viewed from above in a direction orthogonal to the fourth rotation axis, the third band is located between the first band and the second band.

8. The robot according to claim 6, characterized in that, The diameter of the first intermediate pulley is larger than the diameter of the second intermediate pulley. A weight-reducing portion is formed on the first intermediate pulley, which extends through the first intermediate pulley in the direction along the fourth rotation axis.

9. The robot according to claim 1, characterized in that, The robot has a mounting component disposed on the second arm, which houses an inertial sensor module for measuring the inertia of the second arm. When viewed from above along the direction of the second rotation axis, the mounting component overlaps with the imaginary central axis.

10. The robot according to claim 1, characterized in that, The robot has an inertial sensor module, which is configured on the second arm and measures the inertia of the second arm. When viewed from above along the direction of the second rotation axis, the inertial sensor module is located on the other side of the imaginary central axis.

11. The robot according to claim 1, characterized in that, The third rotation axis is located closer to the front end of the second arm than the fourth rotation axis. When viewed from above along the second rotation axis, the through hole is located closer to the third rotation axis than the fourth rotation axis. When viewed from above along the second rotation axis, the through hole overlaps with the intermediate pulley, the intermediate pulley overlaps with the third belt, and the intermediate pulley overlaps with the imaginary central axis. The intermediate pulley includes: a first intermediate pulley with the first belt wound around it; and a second intermediate pulley arranged with the first intermediate pulley in a direction along the fourth rotation axis, and with the second belt wound around it. When viewed from above in a direction orthogonal to the fourth rotation axis, the third band is located between the first band and the second band. The diameter of the first intermediate pulley is larger than that of the second intermediate pulley, and a weight-reducing portion is formed on the first intermediate pulley, extending through the first intermediate pulley in the direction along the fourth rotation axis. The robot has an inertial sensor module disposed on the second arm. When viewed from above along the direction of the second rotation axis, the inertial sensor module overlaps with the imaginary central axis or is located on the other side biased towards the imaginary central axis. The inertial sensor module measures the inertia of the second arm.

12. A robot system, characterized in that, have: Robots; and The control device controls the robot's drive. The robot has the following characteristics: abutment; The first arm is connected to the base and rotates about a first rotation axis relative to the base; The second arm has an arm base connected to the first arm, and the second arm rotates relative to the first arm about a second rotation axis parallel to the first rotation axis. The working head is disposed on the second arm. The working head has a splined shaft along a third rotation axis parallel to the first rotation axis, and a splined nut and a ball screw nut mounted on the splined shaft. When the splined nut is rotated, the splined shaft rotates around the third rotation axis. When the ball screw nut is rotated, the splined shaft moves linearly along the third rotation axis. as well as A first drive mechanism and a second drive mechanism for the spline shaft are disposed within the second arm. The first drive mechanism rotates the spline nut, causing the spline shaft to rotate about the third rotation axis. The second drive mechanism rotates the ball screw nut, causing the spline shaft to move linearly along the third rotation axis. The first drive mechanism for the splined shaft includes: a first motor fixed to the arm base; a first pulley fixed to the rotating shaft of the first motor; a second pulley fixed to the splined nut; an intermediate pulley that rotates relative to the arm base about a fourth rotating shaft parallel to the first rotating shaft; a first belt wound around the first pulley and the intermediate pulley; and a second belt wound around the intermediate pulley and the second pulley. The second drive mechanism for the splined shaft includes: a second motor fixed to the arm base; a third pulley fixed to the rotating shaft of the second motor; a fourth pulley fixed to the ball screw nut; and a third belt wound around the third and fourth pulleys. When viewed from above along the second rotation axis, with the straight line intersecting the second and third rotation axes as the imaginary central axis of the second arm, the first motor and the intermediate pulley are located on one side of the imaginary central axis, and the second motor is located on the other side of the imaginary central axis. A through hole is formed on the arm base, extending through the arm base in the direction along the second rotation axis. When viewed from above in the direction along the second rotation axis, the through hole is positioned biased toward one side of the imaginary central axis.

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