Robot

Abstract

To provide a robot which is excellent in damping performance.SOLUTION: A robot includes: a base; a first arm which rotates around a first axis; a second arm which rotates around a second axis parallel to the first axis; a first shaft which moves in an axial direction of a third axis parallel to the second axis and rotates around the third axis; a first motor which is provided at the second arm and driven so as to move the first shaft in the axial direction of the third axis; a second motor which is provided at the second arm and driven so as to rotate the first shaft around the third axis; a second shaft which is arranged along a fourth axis, which is different from the third axis and parallel to the third axis, and transmits a driving force of the first motor to the first shaft through a connection member; and a pulley which is disposed so that its rotation center overlaps with a central axis of the second shaft and transmits a driving force from the second motor to the first shaft. The second shaft overlaps with a straight line connecting the second axis with the third axis when viewed from an axial direction of the fourth axis.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a robot. [Background technology]

[0002] In recent years, due to rising labor costs and labor shortages in factories, automation of tasks that have been performed manually using various robots and their peripheral devices is accelerating. One example of such robots is the SCARA robot described in Patent Document 1.

[0003] The SCARA robot described in Patent Document 1 comprises a base, a first arm connected to the base, a second arm connected to the first arm, a work shaft connected to the second arm and capable of rising and falling and rotating, and a work shaft lifting mechanism for raising and lowering the work shaft.

[0004] The working shaft lifting mechanism includes a lifting belt that transmits the driving force of the working shaft lifting motor via a drive pulley and a driven pulley, a vertically movable bracket that rotatably holds the working shaft while fixed to the lifting belt and moves up and down together with the working shaft as the lifting belt moves, and a guide shaft that guides the vertical movement of the vertically movable bracket. The working shaft and the guide shaft are disposed offset from the center of the second arm in the longitudinal direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-285282 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the SCARA robot described in Patent Document 1, the weight is not balanced on both sides of the central axis, and there is a risk of excessive vibration occurring when the robot arm is driven. [Means for solving the problem]

[0007] The present invention has been made to solve at least some of the problems described above, and can be realized as follows.

[0008] The robot of the present invention comprises a base and a first arm connected to the base and configured to rotate about a first axis; a second arm connected to the first arm and configured to rotate about a second axis parallel to the first axis; a first shaft connected to the second arm, the first shaft moving in an axial direction of a third shaft parallel to the second shaft and rotating about the third shaft; a first motor provided on the second arm and configured to drive the first shaft to move in an axial direction of the third shaft; a second motor provided on the second arm and configured to drive the first shaft to rotate about the third axis; a second shaft arranged along a fourth axis different from the third axis and parallel to the third axis, the second shaft transmitting a driving force of the first motor to the first shaft via a connecting member; a pulley whose rotation center is arranged to overlap with a central axis of the second shaft and which transmits a driving force from the second motor to the first shaft; The second shaft is characterized in that, when viewed in the axial direction of the fourth shaft, it overlaps with a straight line connecting the second shaft and the third shaft. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side view showing a first embodiment of a robot of the present invention. [Diagram 2] FIG. 2 is a block diagram of the robot system shown in FIG. [Diagram 3] 2 is a partial cross-sectional view showing the inside of a second arm included in the robot arm shown in FIG. 1. [Figure 4]2 is a schematic plan view showing the inside of a second arm included in the robot arm shown in FIG. 1. [Diagram 5] FIG. 11 is a schematic plan view showing the inside of a second arm provided in a second embodiment of a robot of the present invention. [Figure 6] FIG. 11 is a schematic plan view showing the inside of a second arm provided in a robot according to a third embodiment of the present invention. [Figure 7] FIG. 11 is a partial cross-sectional view showing the inside of a second arm provided in a fourth embodiment of a robot of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a robot according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings. First Embodiment Fig. 1 is a side view showing a first embodiment of a robot of the present invention. Fig. 2 is a block diagram of the robot system shown in Fig. 1. Fig. 3 is a partial cross-sectional view showing the inside of a second arm included in the robot arm shown in Fig. 1. Fig. 4 is a schematic plan view showing the inside of the second arm included in the robot arm shown in Fig. 1.

[0011] In addition, in Figs. 1, 3, and 4 (similarly in Figs. 5 and 6), for convenience of explanation, the x-axis, y-axis, and z-axis are illustrated as three mutually orthogonal axes. In addition, hereinafter, the direction parallel to the x-axis is also referred to as the "x-axis direction", the direction parallel to the y-axis is also referred to as the "y-axis direction", and the direction parallel to the z-axis is also referred to as the "z-axis direction". In addition, hereinafter, the tip side of each illustrated arrow is referred to as "+ (plus)" and the base end side is referred to as "- (minus)", the direction parallel to the +x-axis direction is also referred to as the "+x-axis direction", the direction parallel to the -x-axis direction is also referred to as the "-x-axis direction", the direction parallel to the +y-axis direction is also referred to as the "+y-axis direction", the direction parallel to the -y-axis direction is also referred to as the "-y-axis direction", the direction parallel to the +z-axis direction is also referred to as the "+z-axis direction", and the direction parallel to the -z-axis direction is also referred to as the "-z-axis direction". In addition, the direction around the z-axis and the direction around an axis parallel to the z-axis are also referred to as the "u-axis direction".

[0012] For ease of explanation, the +z-axis direction in FIG. 1, i.e., the upper side, will be referred to as "upper" or "upward", and the -z-axis direction, i.e., the lower side, will be referred to as "lower" or "downward". As for the robot arm 20, the base 21 side in FIG. 1 will be referred to as the "base end", and the opposite side, i.e., the end effector 7 side, will be referred to as the "tip". The z-axis direction in FIG. 1, i.e., the up-down direction, will be referred to as the "vertical direction", and the x-axis and y-axis directions, i.e., the left-right direction, will be referred to as the "horizontal direction".

[0013] 1 and 2 is a device used for tasks such as holding, transporting, assembling, and inspecting workpieces such as electronic components and electronic devices. The robot system 100 includes a control device 1, a robot 2, and an end effector 7.

[0014] Moreover, the control device 1 is disposed at a different position from the robot 2, that is, outside the robot 2. Moreover, in the illustrated configuration, the robot 2 and the control device 1 are electrically connected (hereinafter also simply referred to as "connected") by a cable 200, but this is not limiting, and the cable 200 may be omitted and communication may be performed wirelessly. In other words, the robot 2 and the control device 1 may be connected by wired communication, or may be connected by wireless communication.

[0015] In the illustrated configuration, the robot 2 is a horizontal articulated robot, that is, a SCARA robot.

[0016] 1, the robot 2 includes a base 21, a first arm 22, a second arm 23, a third arm 24 that is a working head, and a force detection unit 5. The first arm 22, the second arm 23, and the third arm 24 form a robot arm 20.

[0017] The robot 2 also includes a drive unit 25 that rotates the first arm 22 relative to the base 21, a drive unit 26 that rotates the second arm 23 relative to the first arm 22, a u drive unit 27 that rotates the tip shaft (first shaft) 241 of the third arm 24 relative to the second arm 23, and a z drive unit 28 that moves the tip shaft 241 in the z-axis direction relative to the second arm 23.

[0018] As shown in Figures 1 and 2, the drive unit 25 is built into the base 21 and has a motor 251 that generates a driving force, a reducer 252 that reduces the rotational speed of the motor 251, i.e., the driving force, and a position sensor 253 that detects the rotational angle of the rotation shaft of the motor 251 or the reducer 252.

[0019] The drive unit 26 is built into the housing 230 of the second arm 23, and has a motor 261 that generates a driving force, a reducer 262 that reduces the driving force of the motor 261, and a position sensor 263 that detects the rotation angle of the rotating shaft of the motor 261 or the reducer 262.

[0020] The u drive unit 27 is built into the housing 230 of the second arm 23 , and has a motor 271 that generates a driving force, and a position sensor 273 that detects the rotation angle of the rotation shaft of the motor 271 .

[0021] The z drive unit 28 is built into the housing 230 of the second arm 23, and has a motor 281 that generates a driving force, and a position sensor 283 that detects the rotation angle of the rotation shaft of the motor 281.

[0022] As the motor 251, the motor 261, the motor 271, and the motor 281, for example, a servo motor such as an AC servo motor or a DC servo motor can be used.

[0023] Furthermore, for example, a planetary gear type reducer, a strain wave gear device, etc. can be used as the reducer 252 and the reducer 262. Furthermore, the position sensor 253, the position sensor 263, the position sensor 273, and the position sensor 283 can be, for example, an angle sensor.

[0024] Driving unit 25, driving unit 26, u driving unit 27 and z driving unit 28 are each connected to a corresponding motor driver (not shown), and are controlled by robot control unit 11 of control device 1 via the motor driver.

[0025] The base 21 is fixed to a floor surface (not shown) by, for example, bolts or the like. A first arm 22 is connected to the upper end of the base 21. The first arm 22 is rotatable around a first axis O1 that is vertical to the base 21. When a drive unit 25 that rotates the first arm 22 is driven, the first arm 22 rotates around the first axis O1 in a horizontal plane relative to the base 21. In addition, a position sensor 253 can detect the amount of rotation of the first arm 22 relative to the base 21.

[0026] Further, a second arm 23 is connected to the tip end of the first arm 22. The second arm 23 is rotatable about a second axis O2 that is aligned vertically relative to the first arm 22. The axial direction of the first axis O1 and the axial direction of the second axis O2 are the same. That is, the second axis O2 is parallel to the first axis O1. When the drive unit 26 that rotates the second arm 23 is driven, the second arm 23 rotates around the second axis O2 relative to the first arm 22 within a horizontal plane. In addition, the drive of the second arm 23 relative to the first arm 22, specifically, the amount of rotation, can be detected by the position sensor 263. That is, the second axis O2 is the center of the output rotation shaft of the reducer 262.

[0027] Second arm 23 has a housing 230 having a base portion 231, which is a plurality of walls, a top plate 232, and four side walls 233 connecting these. Inside this housing 230, i.e., on base portion 231, drive unit 26, u drive unit 27, and z drive unit 28 are arranged in this order from the +y-axis side.

[0028] 3, base portion 231 is the bottom portion of second arm 23. Although not shown, base portion 231 has recesses in which u drive unit 27 and z drive unit 28 are disposed.

[0029] Further, a third arm 24 is provided at the tip of the second arm 23. The third arm 24 has a tip shaft 241.

[0030] The tip shaft 241 is rotatable about a third axis O3 along the vertical direction relative to the second arm 23, and is also movable (raised and lowered) in the up and down direction. In this embodiment, the tip shaft 241 is a ball spline shaft, and is the arm at the very tip of the robot arm 20.

[0031] Moreover, various end effectors are detachably connected to the tip of the tip shaft 241. The end effector is not particularly limited, and examples thereof include an end effector for gripping a transported object, an end effector for processing a workpiece, an end effector for inspection, etc. In this embodiment, the end effector 7 is detachably connected.

[0032] In this embodiment, the end effector 7 is not a component of the robot 2, but a part or all of the end effector 7 may be a component of the robot 2. In this embodiment, the end effector 7 is not a component of the robot arm 20, but a part or all of the end effector 7 may be a component of the robot arm 20.

[0033] Further, in this embodiment, the end effector 7 is detachable from the robot arm 20, but this is not limited thereto. For example, the end effector 7 may be inseparable from the robot arm 20.

[0034] As shown in FIG. 2, the control device 1 includes a robot control unit 11, a motor control unit 12 (end effector control unit), a display control unit 13, a memory unit 14, and a reception unit 15, and controls the driving of each part of the robot system 100, such as the robot 2 and the motor 72 of the end effector 7.

[0035] The control device 1 is also configured to be capable of communicating with the robot control unit 11, the motor control unit 12, the display control unit 13, the storage unit 14, and the reception unit 15. That is, the robot control unit 11, the motor control unit 12, the display control unit 13, the storage unit 14, and the reception unit 15 are connected to each other via wired or wireless communication.

[0036] Further, the robot 2 and the end effector 7 are each connected to the control device 1 via wired or wireless communication.

[0037] The robot control unit 11 controls the driving of the robot 2, i.e., the driving of the robot arm 20, etc. The robot control unit 11 is a computer in which a program such as an OS is installed. The robot control unit 11 has, for example, a CPU as a processor, a RAM, and a ROM in which programs are stored. In addition, the functions of the robot control unit 11 can be realized, for example, by executing various programs by the CPU.

[0038] The motor control unit 12 controls the driving of the motor 72. The motor control unit 12 is a computer in which a program such as an OS is installed. The motor control unit 12 has, for example, a CPU as a processor, a RAM, and a ROM in which a program is stored. In addition, the functions of the motor control unit 12 can be realized, for example, by executing various programs by the CPU.

[0039] The display control unit 13 has a function of displaying various screens such as windows, characters, and the like on a display device (not shown).

[0040] The storage unit 14 has a function of storing various types of information (including data, programs, etc.). The storage unit 14 stores a control program, etc. The function of the storage unit 14 can be realized by a so-called external storage device (not shown) such as a ROM. The reception unit 15 has a function of receiving input from an input device (not shown).

[0041] Next, the inside of the second arm 23 will be described. As shown in FIG. 3, provided within the housing 230 of the second arm 23 are a u drive unit 27 that rotates the third arm 24 around the third axis O3, a z drive unit 28 that moves the third arm 24 in the z-axis direction, and a transmission shaft (second shaft) 29.

[0042] 3, the u driving unit 27 has the above-mentioned motor 271 and position sensor 273. The u driving unit 27 is fixed to the bottom of the base portion 231, although not shown.

[0043] Furthermore, z drive unit 28 has the above-mentioned motor 281 and position sensor 283. Z drive unit 28 is fixed to the bottom of base portion 231, although not shown.

[0044] Further, an end portion on the -z axis side of tip shaft 241 is rotatably supported by base portion 231. Further, a spline nut 245 and a pulley 242 are provided on the end portion on the -z axis side of tip shaft 241. A belt 243 is wound around pulley 242. Belt 243 is wound around pulley 242 and pulley 291, which is a relay member.

[0045] Further, a connecting member 244 is fixed to the end of the tip shaft 241 on the +z-axis side via a bearing 247. The connecting member 244 is a member that connects the tip shaft 241 and the transmission shaft 29. The connecting member 244 is fixed to the transmission shaft 29 via a ball screw nut 246. Further, the ball screw nut 246 is provided at the end of the transmission shaft 29 on the +z-axis side, and is attached to the above-mentioned connecting member 244 in a non-rotatable state.

[0046] The transmission shaft 29 is disposed on the +y-axis side of the tip shaft 241, and extends along a fourth axis O4 parallel to the third axis O3. The transmission shaft 29 is supported by the base portion 231 so as to be rotatable.

[0047] A pulley 291, which is a relay member, is provided at the end of the transmission shaft 29 on the -z axis side. The pulley 291 has an insertion hole 290, and has a large diameter portion 292 and a small diameter portion 293. A belt 274 is wound around the large diameter portion 292, and a belt 243 is wound around the small diameter portion 293. The belt 274 is wound around the output shaft of the u drive unit 27.

[0048] The pulley 291 is rotatably fixed to the base portion 231, and is disposed so that the center of rotation overlaps with the central axis of the transmission shaft 29. The transmission shaft 29 can rotate without interference within the insertion hole 290 of the pulley 291. In other words, the transmission shaft 29 and the pulley 291 can rotate about the fourth axis O4 independently of each other.

[0049] A belt 284 is wound around the −z-axis side end of the transmission shaft 29 and the +z-axis side of the pulley 291. The belt 284 is wound around the output shaft of the z drive unit .

[0050] The driving force of the motor 271 is transmitted to the tip shaft 241 via the belt 274, the pulley 291, the belt 243, and the pulley 242. This causes the tip shaft 241 to rotate forward and backward around the z-axis, that is, to rotate. In addition, the position sensor 273 is capable of detecting the amount of rotation of the tip shaft 241 relative to the second arm 23.

[0051] The driving force of the motor 281 is transmitted to the tip shaft 241 via the belt 284, the transmission shaft 29, the ball screw nut 246, the connecting member 244, and the bearing 247. As a result, the ball screw nut 246, the connecting member 244, the bearing 247, and the tip shaft 241 move up and down as a unit in the z-axis direction. In addition, the position sensor 283 is capable of detecting the amount of movement of the tip shaft 241 in the z-axis direction relative to the second arm 23.

[0052] Next, the positional relationship between the transmission shaft 29, the second shaft O2, and the third shaft O3 will be described. Conventionally, the member corresponding to the transmission shaft 29 was disposed at a position offset from the straight line connecting the axis corresponding to the second axis O2 and the axis corresponding to the third axis O3 when viewed in the axial direction of the z-axis. As a result, the weight balance was not achieved on both sides of the straight line connecting the axis corresponding to the second axis O2 and the axis corresponding to the third axis O3, and there was a risk of excessive vibration occurring when the robot arm was driven.

[0053] In contrast, the present invention can solve the above problem by adopting the following configuration. As shown in FIG. 4, in the robot 2, the transmission shaft 29 overlaps with the straight line L connecting the second axis O2 and the third axis O3 in a plan view seen from the axial direction of the fourth axis O4. That is, the second axis O2, the third axis O3, and the fourth axis O4 are substantially at the same position in the y-axis direction. In this embodiment, the straight line L coincides with the center line of the second arm 23 in the longitudinal direction. With this configuration, the weight is balanced on both sides of the straight line L, and it is possible to prevent or suppress the occurrence of excessive vibration when the robot arm 20 is driven. As a result, the robot 2 has excellent vibration control properties.

[0054] In this manner, the robot 2 includes the base 21, the first arm 22 connected to the base 21 and rotatable about the first axis O1, the second arm 23 connected to the first arm 22 and rotatable about the second axis O2 parallel to the first axis O1, the tip shaft 241 which is a first shaft connected to the second arm 23 and moves in the axial direction of the third axis O3 parallel to the second axis O2 and rotates about the axis of the third axis O3, the motor 281 which is a first motor provided on the second arm 23 and drives the tip shaft 241 to move in the axial direction of the third axis O3, and the motor 281 which is a first motor provided on the second arm 23 and drives the tip shaft 241 to move in the axial direction of the third axis O3. The motor 271 is a second motor that drives the motor 281 to rotate around the third axis O3, a transmission shaft 29 is a second shaft that is arranged along a fourth axis O4 that is different from the third axis O3 and parallel to the third axis O3 and transmits the driving force of the motor 281 to the tip shaft 241 via a connecting member 244, and a pulley 291 is arranged so that the center of rotation overlaps with the central axis of the transmission shaft 29 and transmits the driving force from the motor 271 to the tip shaft 241, and the transmission shaft 29 overlaps with a straight line L that connects the second axis O2 and the third axis O3 when viewed from the axial direction of the fourth axis O4. This allows the weight to be balanced on both sides of the straight line L, and it is possible to prevent or suppress the occurrence of excessive vibration when the robot arm 20 is driven. As a result, the robot 2 has excellent vibration control properties.

[0055] Moreover, the rotation centers of motor 271 and motor 281 are each located on line L. In other words, motor 271 and motor 281 are also located on the same line as tip shaft 241 and transmission shaft 29. With this configuration, the weight balance is further improved on both sides of line L, and it is possible to more effectively prevent or suppress the occurrence of excessive vibration when robot arm 20 is driven. In particular, such a configuration is advantageous when motor 271 and motor 281 have different weights, and further when u drive unit 27 and z drive unit have different weights.

[0056] In this manner, the rotation center of the motor 281 serving as the first motor and the rotation center of the motor 271 serving as the second motor overlap with the straight line L connecting the second axis O2 and the third axis O3. This makes it possible to achieve a better balance of weight on both sides of the straight line L, and more effectively prevent or suppress the occurrence of excessive vibrations when the robot arm 20 is driven.

[0057] In addition, the distance between the rotation center of the motor 281, which is the first motor, and the second axis O2 is shorter than the distance between the rotation center of the motor 281 and the fourth axis O4, and the distance between the rotation center of the motor 271, which is the second motor, and the second axis O2 is shorter than the distance between the rotation center of the motor 271 and the fourth axis O4. This allows the center of gravity of the second arm 23 to be located on the base end side. This makes it possible to prevent inertia from becoming too large when driving the robot arm 20. As a result, it is possible to prevent an increase in power consumption and excessive heat generation from components such as regenerative resistors.

[0058] As described above, the pulley 291 is provided with an insertion hole 290 through which the transmission shaft 29, which is the second shaft, is inserted, and the transmission shaft 29 and the pulley 291 rotate independently. This allows the center of rotation of the pulley 291 to be located on the straight line L. Thus, the weight balance is improved on both sides of the straight line L compared to when the pulley 291 is located on either side of the straight line L. This makes it possible to more effectively prevent or suppress excessive vibrations from occurring when the robot arm 20 is driven.

[0059] Similarly, in this embodiment, the u drive unit 27 is a unit in which the motor 271 and the position sensor 273 are fixed coaxially, but the present invention is not limited to this, and the motor 271 and the position sensor 273 may be arranged in different positions from each other.

[0060] Similarly, in this embodiment, the z drive unit 28 is a unit in which the motor 281 and the position sensor 283 are fixed coaxially, but the present invention is not limited to this, and the motor 281 and the position sensor 283 may be arranged in different positions from each other.

[0061] <Second embodiment> FIG. 5 is a schematic plan view showing the inside of a second arm provided in a robot according to a second embodiment of the present invention.

[0062] The second embodiment of the robot of the present invention will be described below with reference to this figure, and the differences from the first embodiment will be described below.

[0063] As shown in FIG. 5, in this embodiment, the u driving unit 27 and the z driving unit 28 are arranged on opposite sides of the line L. In the illustrated configuration, the motor 271 and the motor 281 are arranged with their rotation centers symmetrical with respect to the line L. This allows the weight balance on both sides of the line L to be well maintained, and the u driving unit 27 and the z driving unit 28 can be arranged at the same position in the y-axis direction. Therefore, the length of the second arm 23 in the y-axis direction can be designed to be shorter than that in the first embodiment. As a result, the robot 2 has excellent vibration damping properties and can be made smaller in size.

[0064] If the weights of u drive unit 27 and z drive unit 28 are different, it is preferable to vary the distances from line L in consideration of the balance between them.

[0065] In this way, the motor 281, which is the first motor, and the motor 271, which is the second motor, are arranged symmetrically with respect to the straight line connecting the second axis O2 and the third axis O3 as the axis of symmetry. This provides excellent vibration damping and allows the robot 2 to be made compact.

[0066] Moreover, the motor 281 which is the first motor and the motor 271 which is the second motor are disposed between the second axis O2 and the fourth axis O4. This makes it possible to more effectively reduce the size of the robot 2.

[0067] <Third embodiment> FIG. 6 is a schematic plan view showing the inside of a second arm provided in a robot according to a third embodiment of the present invention.

[0068] The third embodiment of the robot of the present invention will be described below with reference to this figure, and the differences from the second embodiment will be described below.

[0069] As shown in FIG. 6, in this embodiment, the u driving unit 27 and the z driving unit 28 are located on the +y-axis side of the second axis O2. That is, the motor 281, which is the first motor, and the motor 271, which is the second motor, are located on the opposite side of the second axis O2 to the third axis. This allows the center of gravity of the second arm 23 to be moved further toward the base end. This makes it possible to prevent the inertia from becoming too large when driving the robot arm 20. As a result, it is possible to prevent an increase in power consumption and excessive heat generation in components such as regenerative resistors.

[0070] <Fourth embodiment> FIG. 7 is a partial cross-sectional view showing the inside of a second arm 23 provided in a fourth embodiment of a robot of the present invention.

[0071] The fourth embodiment of the present invention will be described below with reference to this figure, and the differences from the third embodiment will be described below.

[0072] 7, in this embodiment, drive unit 26 is provided so as to protrude toward the -z-axis side of second arm 23. That is, drive unit 26 is provided at a position not overlapping with u drive unit 27, belt 274, z drive unit 28, and belt 284 in the axial direction of the z-axis. This makes it possible to reduce interference between drive unit 26 and belt 274 and belt 284 without increasing the size of second arm 23.

[0073] Although the robot of the present invention has been described above based on the illustrated embodiment, the present invention is not limited to this, and the configuration of each part can be replaced with any configuration having a similar function. In addition, any other configuration may be added.

[0074] In addition, in the above embodiment, the number of rotation axes of the robot arm is three, but the present invention is not limited to this, and the number of rotation axes of the robot arm may be, for example, two or four or more. That is, in the above embodiment, the number of arms is three, but the present invention is not limited to this, and the number of arms may be, for example, two or four or more. [Explanation of symbols]

[0075] 1...control device, 2...robot, 7...end effector, 11...robot control unit, 12...motor control unit, 13...display control unit, 14...storage unit, 15...reception unit, 20...robot arm, 21...base, 22...first arm, 23...second arm, 24...third arm, 25...drive unit, 26...drive unit, 27...u drive unit, 28...z drive unit, 29...transmission shaft (second shaft), 31...gripping unit, 32...side gauge, 33...stop side gauge, 41...display device, 42...input device, 71...mounting unit, 72...motor, 100...robot system, 200...cable, 230...housing, 231...base unit, 232 ...top plate, 233...side wall, 241...tip shaft (first shaft), 242...pulley, 243...belt, 244...connecting member, 245...spline nut, 246...ball screw nut, 247...bearing, 251...motor, 252...reduction gear, 253...position sensor, 261...motor, 262...reduction gear, 263...position sensor, 271...motor, 273...position sensor, 274...belt, 281...motor, 283...position sensor, 284...belt, 290...insertion hole, 291...pulley (relay member), 292...large diameter portion, 293...small diameter portion, L...straight line, O1...first axis, O2...second axis, O3...third axis, O4...fourth axis

Claims

1. The base and a first arm connected to the base and configured to rotate about a first axis; a second arm connected to the first arm and configured to rotate about a second axis parallel to the first axis; a first shaft connected to the second arm, the first shaft moving in an axial direction of a third shaft parallel to the second shaft and rotating about the third shaft; a first motor provided on the second arm and configured to drive the first shaft to move in an axial direction of the third axis; a second motor provided on the second arm and configured to drive the first shaft to rotate about the third axis; a second shaft disposed along a fourth axis different from the third axis and parallel to the third axis, the second shaft connected to the first shaft via a connecting member; Equipped with the second shaft overlaps with a straight line connecting the second shaft and the third shaft when viewed from an axial direction of the fourth shaft, the first motor and the second motor are disposed on opposite sides of the straight line, a distance between a rotation center of the first motor and the second shaft is shorter than a distance between a rotation center of the first motor and the fourth shaft; A robot characterized in that a distance between a rotation center of the second motor and the second shaft is shorter than a distance between a rotation center of the second motor and the fourth shaft.

2. The robot according to claim 1 , wherein the first motor and the second motor are disposed between the second axis and the fourth axis.

3. The robot according to claim 1 , wherein the first motor and the second motor are disposed on an opposite side of the second shaft to the third shaft.

4. The robot as described in claim 1, wherein the distance between the first motor and the straight line is different from the distance between the second motor and the straight line.

5. The base and a first arm connected to the base and configured to rotate about a first axis; a second arm connected to the first arm and configured to rotate about a second axis parallel to the first axis; a first shaft connected to the second arm, the first shaft moving in an axial direction of a third shaft parallel to the second shaft and rotating about the third shaft; a first motor provided on the second arm and configured to drive the first shaft to move in an axial direction of the third axis; a second motor provided on the second arm and configured to drive the first shaft to rotate about the third axis; a second shaft disposed along a fourth axis different from the third axis and parallel to the third axis, the second shaft connected to the first shaft via a connecting member; Equipped with the second shaft overlaps with a straight line connecting the second shaft and the third shaft when viewed from an axial direction of the fourth shaft, A robot characterized in that the first motor and the second motor overlap with a straight line connecting the second axis and the third axis.

6. A robot as described in any one of claims 1 to 5, wherein the second shaft has a ball screw nut, and the connecting member is attached to the ball screw nut.

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