Robot

Abstract

A robot (100) comprises a robot arm (10), a drive pulley (55), a driven pulley (56), a drive unit (71), a belt member (58), and an intermediate pulley (57). The drive unit (71) serves as a drive source for rotating the drive pulley (55). The belt member (58) is fixed to the drive pulley (55) and the driven pulley (56), and transmits power from the drive pulley (55) to the driven pulley (56). The intermediate pulley (57) is disposed between the drive pulley (55) and the driven pulley (56) and presses the belt member (58) in directions in which the belt member is wound around the drive pulley (55) and the driven pulley (56).

Description

robot

[0001] This disclosure pertains to robots.

[0002] Robots have been known conventionally. For example, Japanese Patent Publication No. 6786291 discloses an industrial robot for transporting objects as workpieces. The industrial robot described in Japanese Patent Publication No. 6786291 has a hollow arm. Inside the hollow arm are two pulleys and a belt stretched between the two pulleys. This belt is a steel belt made of steel plate and is fixed to each of the two pulleys by being wrapped around them in a ring shape and secured by screws.

[0003] Patent No. 6786291

[0004] However, in the industrial robot described in the above-mentioned Japanese Patent Publication No. 6786291, the belt member is screwed and fixed to each of the two pulleys in a circular fashion. Therefore, when one pulley is rotated to move the belt member, it is not possible to feed the belt member beyond the position fixed to the pulley. In other words, when one pulley is rotated, it is not possible to rotate it so that the position where the belt member is fixed on the pulley crosses the common outer tangent of the two pulleys. Therefore, in the configuration of the above-mentioned Japanese Patent Publication No. 6786291, when the rotation of one pulley is transmitted to the other pulley via the belt member, the operating range of the other pulley is limited. Thus, it is desirable to expand the operating range when power is transmitted by a belt member fixed to a pulley.

[0005] This disclosure is made to solve the problems described above, and one of its purposes is to provide a robot that can expand the range of motion when power is transmitted by a belt member fixed to a pulley.

[0006] To achieve the above objective, a robot according to one aspect of this disclosure comprises a robot arm, a drive pulley disposed inside the robot arm, a driven pulley disposed inside the robot arm separately from the drive pulley, a drive unit which serves as a drive source for rotating the drive pulley, a belt member fixed to each of the drive pulley and the driven pulley and transmitting power from the drive pulley to the driven pulley, and at least one intermediate pulley disposed between the drive pulley and the driven pulley and pressing the belt member in a direction that wraps around each of the drive pulley and the driven pulley.

[0007] A robot according to one aspect of this disclosure, as described above, includes at least one intermediate pulley positioned between a drive pulley and a driven pulley, which presses the belt member in a direction that causes it to wrap around each of the drive pulley and the driven pulley. As a result, because the belt member is pressed by at least one intermediate pulley in a direction that causes it to wrap around each of the drive pulley and the driven pulley, when the drive pulley is rotated, the portion of the belt member fixed to the drive pulley can be rotated to an inward position beyond the common outer tangent of the drive pulley and the driven pulley. Therefore, the range of motion of the belt member when the drive pulley is rotated can be increased. Consequently, the range of motion when power is transmitted by a belt member fixed to a pulley can be increased.

[0008] According to this disclosure, it is possible to provide a robot that can expand the operating range when power is transmitted by a belt member fixed to a pulley, as described above.

[0009] This is a schematic perspective view showing a robot according to one embodiment of the present disclosure. This is a schematic side view showing a robot according to one embodiment. This is a schematic cross-sectional view showing a robot arm of a robot according to one embodiment. This is a diagram illustrating the fixing of a belt member to a pulley located on the base end side of the tip link. This is a diagram illustrating the fixing of a belt member to a pulley located on the tip side of the tip link. This is a schematic diagram showing the arrangement of the drive winding portion of the belt member and the pulley that presses the belt member against it. This is a schematic diagram showing the arrangement of the driven winding portion of the belt member and the pulley that presses the belt member against it.

[0010] The embodiments of this disclosure will be described below with reference to the drawings.

[0011] The configuration of a robot 100 according to one embodiment of the present disclosure will be described with reference to Figures 1 to 7.

[0012] (Robot Configuration) As shown in Figure 1, the robot 100 according to this embodiment is a transport robot that transports a workpiece W. The workpiece W is a disc-shaped substrate or a jig that mimics a disc-shaped substrate. The workpiece W is, for example, a glass substrate or a silicon substrate. In other words, the robot 100 of this embodiment is a substrate transport robot that transports substrates. Furthermore, the robot 100 is a vacuum robot that is placed in a vacuum environment. For example, the robot 100 transports the workpiece W, which is a substrate, in a space such as a chamber that is kept under vacuum. Note that the term "disc-shaped" here is a broad concept that includes shapes that have been deformed from a circle. A "disc-shaped" substrate includes a substrate that has a notch or orientation flat that serves as a position reference. Furthermore, "disc-shaped" includes not only perfect circles but also ellipses.

[0013] The robot 100 comprises a pair of robot arms 10 and 20, a pair of hands 30 and 40, and a base 90. The base 90 has a cylindrical shape, and devices such as a drive unit 71, a drive unit 72, a drive unit 73, and a control unit 80 are arranged in its internal space. Each of the hands 30 and 40 is attached to the respective end of the robot arm 10 and robot arm 20. Each of the robot arms 10 and 20 is supported by the base 90 and rotates and extends relative to the base 90 by driving multiple joints. Each of the robot arms 10 and 20 also moves up and down relative to the base 90 by driving a lifting mechanism. The base ends of the robot arms 10 and 20 are arranged to overlap in the vertical direction. The base end of the robot arm 10 is positioned lower than the base end of the robot arm 20. Each of the robot arms 10 and 20 operates independently through control processing by the control unit 80. Hands 30 and 40 are examples of "substrate holding hands".

[0014] Robot 100 is a dual-arm type substrate transport robot that loads and unloads workpieces W, which are substrates, and is a horizontally articulated substrate transport robot. Robot arm 10 is a horizontally articulated robot arm having a base link 11 and an end link 12 that rotate relative to each other along the horizontal direction, with the vertical direction (Z) as the axis of rotation. Robot arm 20 is similarly a horizontally articulated robot arm having a base link 21 and an end link 22 that rotate relative to each other along the horizontal direction, with the vertical direction (Z) as the axis of rotation. Here, "horizontal" means parallel to the installation surface on which robot 100 is installed. If robot 100 is placed on an inclined surface or a wall, robot arms 10 and 20 rotate in a plane parallel to the installation surface, which is different from the horizontal plane relative to gravity.

[0015] Each of the robot arms 10 and 20 performs rotational and extension movements independently relative to the base 90. Specifically, the base end of the base link 11 of the robot arm 10 is rotatably attached to the base 90. The base end of the tip link 12 is rotatably attached to the tip end of the base link 11. The hand 30 is rotatably attached to the tip end of the tip link 12. The connection between the base end of the base link 11 and the base 90 constitutes a shoulder joint. The connection between the tip end of the base link 11 and the base end of the tip link 12 constitutes an elbow joint. The connection between the tip end of the tip link 12 and the hand 30 constitutes a wrist joint.

[0016] The base end of the base link 21 of the robot arm 20 is rotatably attached to the base 90 via the base link 11. The base end of the tip link 22 is rotatably attached to the tip end of the base link 21. The hand 40 is rotatably attached to the tip end of the tip link 22. The connection between the base end of the base link 21 and the base 90 constitutes the shoulder joint. The connection between the tip end of the base link 21 and the base end of the tip link 22 constitutes the elbow joint. The connection between the tip end of the tip link 22 and the hand 40 constitutes the wrist joint.

[0017] Each of the hands 30 and 40 holds a workpiece W, which is a substrate. Specifically, in each of the hands 30 and 40, one disc-shaped workpiece W is placed on a blade member, which is a thin plate-shaped support plate. In addition, the blade member that supports the workpiece W in each of the hands 30 and 40 has a U-shape with a bifurcated tip, and supports the back surface of the disc-shaped workpiece W from the Z2 direction, which is vertically downward. Each of the hands 30 and 40 is a passive type substrate holding hand that holds the workpiece W, which is a substrate, in a state where it is placed without being fixed.

[0018] Furthermore, in this embodiment, each of the robot arms 10 and 20 has a hollow arm space. For example, robot 100 is in a high vacuum 10 －１ From Pa to 10 －５The robotic arms are placed in a chamber or similar chamber filled with gas at a pressure of up to Pa. The arm space of the robotic arm 10 is a high vacuum with a pressure equal to the external vacuum environment, with the internal spaces of the base link 11 and the tip link 12 communicating with each other. Similarly, the arm space of the robotic arm 20 is a high vacuum with a pressure equal to the external vacuum environment, with the internal spaces of the base link 21 and the tip link 22 communicating with each other. In addition, the arm spaces of the robotic arms 10 and 20 are in communication with the internal space of the base portion 90. Note that "vacuum" as used here refers to a space filled with gas at a pressure lower than normal atmospheric pressure.

[0019] As shown in Figure 2, the base portion 90 contains drive units 71, 72, and 73. Drive unit 71 drives the elbow and wrist joints of the robot arm 10. Drive unit 72 drives the elbow and wrist joints of the robot arm 20. Drive unit 73 drives the shoulder joints of the robot arms 10 and 20. Drive units 71, 72, and 73 include a servo motor as a drive source and an encoder for detecting the rotation of the servo motor. In addition to drive units 71, 72, and 73, the base portion 90 also contains a drive unit for raising and lowering the robot arms 10 and 20.

[0020] Furthermore, as shown in Figure 1, the robot 100 is equipped with a control unit 80. The control unit 80 is a computer having a processing unit such as a CPU (Central Processing Unit). The control unit 80 includes a storage device including flash memory such as an SSD (Solid State Drive). The control unit 80 is a robot controller that controls the operation of each part of the robot 100 based on programs and parameters stored in the storage device. The control unit 80 includes, for example, a main control unit that controls the operation of each joint of the robot arms 10 and 20, a servo control unit that controls the drive current output to servo motors, which are drive sources arranged at each joint of the robot arms 10 and 20, based on commands from the main control unit, and a drive circuit unit that supplies power to each joint of the robot arms 10 and 20. In the control unit 80, for example, the main control unit and the servo control unit each have a processing unit such as a CPU separately from each other. The control unit 80 controls the operation of the servo motors based on the outputs from the encoders in the drive units 71, 72, and 73, thereby controlling the operation of the robot arms 10 and 20 by feedback control. The control unit 80 controls the transport operation for transporting multiple workpieces W.

[0021] <Details of the robot arm> As shown in Figure 2, a belt and pulley mechanism for transmitting the driving force of the drive unit 71 is arranged in the robot arm 10. Specifically, a pulley 51, a pulley 52, a belt member 53, and a belt member 54 for transmitting the driving force of the drive unit 71 are arranged inside the base link 11 of the robot arm 10. The pulley 51 is located on the base end side of the base link 11. The pulley 52 is located on the tip side of the base link 11. Each of the belt member 53 and the belt member 54 is stretched between the pulley 51 and the pulley 52. ​​Each of the belt member 53 and the belt member 54 is fixed to the pulley 51 and the pulley 52. ​​The rotation of one side of the drive-side pulley 51 is transmitted to the pulley 52 by the belt member 53, and the rotation of the other side of the pulley 51 is transmitted to the pulley 52 by the belt member 54. Belt members 53 and 54 are fixed to pulleys 51 and 52, respectively, with a vertical offset between them.

[0022] Furthermore, pulleys 55, 56, 57, and a belt member 58 are arranged inside the tip link 12 of the robot arm 10. Pulley 55 is located on the base end side inside the tip link 12. Pulley 56 is located separately from pulley 55 on the tip side inside the tip link 12. Pulley 57 is located inside the tip link 12 between pulley 55 and pulley 56. The belt member 58 is stretched between pulley 55 and pulley 56. In this embodiment, the belt member 58 is fixed to each of pulleys 55 and 56, and transmits power from pulley 55 to pulley 56. Each of the belt members 53, 54, and 58 is made of metal, such as stainless steel. However, each of the belt members 53, 54, and 58 may be made of a material other than metal, such as rubber. Also, pulley 55 is an example of a drive pulley. Pulley 56 is an example of a driven pulley. Pulley 57 is an example of an intermediate pulley.

[0023] Pulley 51 is connected to a rotating shaft that transmits the driving force of the drive unit 71. In the robot arm 10, the base link 11 and the tip link 12 are connected to each other via a hollow shaft portion 13. Pulley 52 is supported on the lower end side of the shaft portion 13. Inside the shaft portion 13, there is a connecting portion 14 that is fixed to the base link 11 and rotates independently of the shaft portion 13. Pulley 52 is connected to the base end side of the tip link 12 via the shaft portion 13. Pulley 55 is supported on the upper end side of the connecting portion 14. Pulley 56 is connected to a hand 30 attached to the tip of the tip link 12 via a connecting portion 15.

[0024] When the drive unit 71 rotates the rotating shaft extending from the base unit 90 to the robot arm 10, the pulley 51 rotates along the horizontal plane. The rotation of pulley 51 is transmitted by the belt members 53 and 54, causing pulley 52 to rotate along the horizontal plane inside the base link 11. When pulley 52 rotates, the tip link 12 rotates via the shaft 13. When pulley 52 rotates and the tip link 12 rotates, pulley 55 rotates along the horizontal plane inside the tip link 12 via the connecting part 14 fixed to the base link 11. In other words, the drive unit 71 is the drive source that rotates pulley 55 in the tip link 12. Then, inside the tip link 12, the rotation of pulley 55 is transmitted by the belt member 58, causing pulley 56 to rotate. When pulley 56 rotates, the hand 30 rotates via the connecting part 15. In other words, the hand 30 is connected to the pulley 56 and operates by the rotation of the pulley 56. In this way, the pulleys 51, 52, belt member 53, 54, 55, 56, and 58 work together, and the drive unit 71 drives the elbow joint and wrist joint of the robot arm 10 in conjunction.

[0025] In the robot arm 20, similar to the robot arm 10, a belt and pulley mechanism is provided to transmit the driving force of the drive unit 72. Specifically, pulleys 61, 62, belt member 63, and belt member 64 are arranged inside the base link 21 of the robot arm 20 to transmit the driving force of the drive unit 72. In addition, pulleys 65, 66, 67, and belt member 68 are arranged inside the tip link 22 of the robot arm 20. The configuration of pulleys 61, 62, belt member 63, and belt member 64 in the base link 21 of the robot arm 20 is the same as that of pulleys 51, 52, belt member 53, and belt member 54 in the base link 11 of the robot arm 10, respectively. Furthermore, the configuration of the pulleys 65, 66, 67, and belt member 68 in the tip link 22 of the robot arm 20 is the same as that of the pulleys 55, 56, 57, and belt member 58 in the tip link 12 of the robot arm 10, respectively. Pulley 65 is an example of a drive pulley. Pulley 66 is an example of a driven pulley. Pulley 67 is an example of an intermediate pulley.

[0026] Similar to the robot arm 10, the pulley 61 located on the base end side of the base link 21 is connected to a rotating shaft that transmits the driving force of the drive unit 72. The rotating shaft to which the pulley 51 of the robot arm 10 is connected and the rotating shaft to which the pulley 61 of the robot arm 20 is connected are different from each other. In the robot arm 20, the base link 21 and the tip link 22 are connected to each other via a hollow shaft portion 23. Inside the shaft portion 23, a connecting portion 24 is arranged which is fixed to the base link 21 and rotates independently of the shaft portion 23. The pulley 65 is supported on the upper end side of the connecting portion 24. The pulley 66 is connected to a hand 40 attached to the tip of the tip link 22 via a connecting portion 25. In the robot arm 20, as in the robot arm 10, when the rotating shaft extending from the base portion 90 to the robot arm 20 is rotated by the drive unit 72, the pulley 61 rotates along the horizontal plane. The rotation of pulley 61 is transmitted by belt members 63 and 64, causing pulley 62 to rotate along the horizontal plane inside the base link 21. When pulley 62 rotates, the tip link 22 rotates via the shaft 23. When pulley 62 rotates and the tip link 22 rotates, pulley 65 rotates along the horizontal plane inside the tip link 22 via the connecting part 24 fixed to the base link 21. In other words, the drive unit 72 is the drive source that rotates pulley 65 in the tip link 22. The rotation of pulley 65 is then transmitted by belt member 68, causing pulley 66 to rotate. When pulley 66 rotates, the hand 40 rotates via the connecting part 25. In other words, the hand 40 is connected to pulley 66 and operates in response to the rotation of pulley 66. In this way, similar to the robot arm 10, the pulleys 61, 62, belt member 63, belt member 64, pulley 65, pulley 66, and belt member 68 work together, causing the elbow joint and wrist joint of the robot arm 20 to be driven in conjunction by the drive unit 72.

[0027] (Configuration of the end link) Next, the details of the configuration of the end link 12 in the robot arm 10 will be explained with reference to Figures 3 to 7. Note that the details of the configuration of the end link 22 in the robot arm 20 will be omitted as the configuration is the same.

[0028] As shown in Figure 3, in this embodiment, the pulley 57 presses the belt member 58 in a direction that wraps it around each of the pulleys 55 and 56. When viewed from the direction in which the rotation axes of the pulleys 55 and 56 extend, at least a portion of the pulley 57 is positioned closer to the center line L2 connecting the center 55c, which is the rotation axis of the pulley 55, and the center 56c, which is the rotation axis of the pulley 56, than to the common outer tangent line L1 between the pulleys 55 and 56. Specifically, when viewed from the direction in which the rotation axes of the pulleys 55 and 56 extend, the center 57c of the pulley 57 is positioned at a location shifted in the pressing direction P that presses the belt member 58, relative to the center line L2 connecting the centers 55c and 56c.

[0029] Pulleys 55 and 56 have a circular shape in a plan view taken from the direction in which the axis of rotation extends. If the belt member 58 is wrapped around pulleys 55 and 56 without using pulley 57, the belt member 58 will be positioned at the common outer tangent line L1 between the two circular shapes of pulleys 55 and 56. In this embodiment, pulley 57 is positioned inside the tip link 12 as an idler pulley so as to press the belt member 58 from the outside towards the space between pulleys 55 and 56 along the pressing direction P. At this time, the center 57c of pulley 57 is positioned so as to push the belt member 58 further in the pressing direction P from the position of the common outer tangent line L1 than the center line L2. The center 57c of pulley 57 is positioned on the opposite side of the center line L2 from the common outer tangent line L1. The pressing direction P is perpendicular to the center line L2 when viewed from the direction in which the rotation axes of the pulleys 55 and 56 extend, and is also in the direction from the outside to the inside of the belt member 58 which is wrapped around the pulleys 55 and 56 in an annular shape.

[0030] Furthermore, in this embodiment, pulleys 55 and 56 have different outer diameters. Specifically, the driven end-side pulley 56 has a larger outer diameter than the driving end-side pulley 55. The pulley 57 is positioned inside the robot arm 10, closer to the pulley 55, which has the smaller outer diameter than the other pulley 56. When the elbow joint and wrist joint are linked, the rotation angle of the end-side link 12 relative to the end-side link 11 and the rotation angle of the hand 30 relative to the end-side link 12 are in a ratio of 2:1. The outer diameter of pulley 55 is smaller than the outer diameter of pulley 56. In this embodiment, pulley 57 has an outer diameter that is smaller than the outer diameter of pulley 55 and smaller than the outer diameter of pulley 56. By positioning pulley 57 between pulleys 55 and 56, the width of the robot arm 10 in the direction of extension of the end-side link 12 is reduced. In other words, in a plan view, in the width direction perpendicular to the central line L2, the pulley 57 is positioned in a region smaller than the region where the pulley 55 is located, and also smaller than the region where the pulley 56 is located.

[0031] Furthermore, in this embodiment, the belt member 58 includes a straight portion 58a and a bent portion 58b. The straight portion 58a is the part of the belt member 58 that extends linearly from pulley 55 to pulley 56. That is, the straight portion 58a is the part that is arranged along the other common external tangent line opposite to the common external tangent line L1. The bent portion 58b is the part that extends from pulley 55 to pulley 56 while being pressed by pulley 57. The bent portion 58b is the part that is bent toward the central straight line L2 by being pressed against pulley 57. The belt member 58 is wrapped around pulleys 55 and 56 in an annular shape by fixing the straight portion 58a and the bent portion 58b to pulleys 55 and 56, respectively. The belt member 58 is a single strip-shaped member, with its central portion fixed to pulley 55 and both end portions fixed to pulleys 56. As a result, the belt member 58 is wrapped around the pulleys 55 and 56 in an annular shape. Furthermore, the straight portion 58a and the bent portion 58b of the belt member 58 are positioned at the same height relative to each other in the direction in which the respective rotation axes of the pulleys 55 and 56 extend. Therefore, as shown in Figure 2, when viewed from the side of the robot arm 10, the straight portion 58a and the bent portion 58b of the belt member 58 are arranged to overlap each other.

[0032] As shown in Figure 4, each of the ends of the belt member 58 is fixed to the pulley 56 by fixing members 56a and 56b. Fixing members 56a and 56b are, for example, fastening members such as screws. Also, as shown in Figure 5, the central part of the belt member 58 is fixed to the pulley 55 by fixing member 55a. Fixing member 55a is, for example, a fastening member such as a screw. The strip-shaped belt member 58 has holes in each of its ends and in its central part into which fixing members 56a, 56b, and 55a are inserted. The belt member 58 is fixed to the pulleys 55 and 56 at the positions of the holes into which fixing members 56a, 56b, and 55a are inserted. In this embodiment, the angular range from position R1, where the straight portion 58a of the belt member 58 is in contact with the bent portion 58b, to position R2, where the bent portion 58b is in contact with the pulley 55, is the operating range of the pulley 55. Specifically, in the pulley 55, the range between position R1 and position R2 is the range in which the fixing member 55a can be positioned. That is, the operating range of the pulley 55 is from the state in which the fixing member 55a is positioned at position R1 to the state in which the fixing member 55a is positioned at position R2 after rotating counterclockwise.

[0033] Here, as shown in Figure 6, the belt member 58 has a drive winding portion 58c that is wrapped around the pulley 55 as the pulley 55 moves. The drive winding portion 58c is the part of the belt member 58 that contacts the pulley 55 when the pulley 55 is rotated within the operating range of the pulley 55. In this embodiment, the pulley 57 is positioned so that it does not contact the drive winding portion 58c even when the belt member 58 moves as the pulley 55 moves. That is, even when the pulley 55 is rotated from a position R1 to a position R2 where the belt member 58 is fixed by the fixing member 55a, the drive winding portion 58c that was in contact with the pulley 55 does not come into contact with the pulley 57. The pulley 57 is positioned sufficiently far from the pulley 55 so that the drive winding portion 58c, which is the part that is curved when it comes into contact with the pulley 55, does not curve in the opposite direction when it comes into contact with the pulley 57.

[0034] As shown in Figure 7, the belt member 58 has a driven winding portion 58d that wraps around the pulley 56 as the pulley 55 moves. The driven winding portion 58d is the part of the belt member 58 that comes into contact with the pulley 56 when the pulley 55 is rotated within the operating range of the pulley 55. Similarly, in this embodiment, the pulley 57 is positioned so that it does not come into contact with the driven winding portion 58d even when the belt member 58 moves as the pulley 55 moves. That is, even when the pulley 55 is rotated within the operating range, the driven winding portion 58d that was in contact with the pulley 56 does not come into contact with the pulley 57. The pulley 57 is positioned sufficiently far from the pulley 56 so that the driven winding portion 58d, which is the part that is curved when it comes into contact with the pulley 56, does not curve in the opposite direction when it comes into contact with the pulley 57.

[0035] Furthermore, as shown in Figure 3, the robot 100 is equipped with an adjustment mechanism 59 for adjusting the position of the pulley 57. In this embodiment, the pulley 57 also functions as a tensioner for adjusting the tension of the belt member 58 by adjusting its position using the adjustment mechanism 59. The adjustment mechanism 59 adjusts the position of the pulley 57 in the pressing direction P that presses the belt member 58 against it. The adjustment mechanism 59 includes, for example, a screw member that changes the position of the center 57c of the pulley 57. By adjusting the amount the screw member is threaded in, the position of the pulley 57 in the pressing direction P is adjusted, and the tension of the belt member 58 is adjusted. In the robot 100, for example, during shipping or maintenance, the tension of the belt member 58 is adjusted by the operator adjusting the amount the screw member of the adjustment mechanism 59 is threaded in.

[0036] [Effects of this embodiment] In this embodiment, as described above, the robot 100 is provided with at least one intermediate pulley pulley 57 positioned between the drive pulley pulley 55 and the driven pulley pulley 56, and pressing the belt member 58 in a direction that wraps around each of the pulleys 55 and 56. The robot 100 is also provided with at least one intermediate pulley pulley 67 positioned between the drive pulley pulley 65 and the driven pulley pulley 66, and pressing the belt member 68 in a direction that wraps around each of the pulleys 65 and 66. As a result, the belt member 58 is pressed by the pulley 57 in a direction that wraps around each of the pulleys 55 and 56, so when the pulley 55 is rotated, the portion of the pulley 55 to which the belt member 58 is fixed can be rotated to an inward position beyond the common outer tangent line L1 of the pulleys 55 and 56. Furthermore, since the belt member 68 is pressed by the pulley 67 in a direction that wraps around each of the pulleys 65 and 66, when the pulley 65 is rotated, the portion of the pulley 65 to which the belt member 68 is fixed can be rotated to an inward position that exceeds the common outer tangent of the pulleys 65 and 66. As a result, the range of movement of the belt members 58 and 68 when the pulleys 55 and 65 are rotated can be expanded. Consequently, the range of operation when power is transmitted by the belt member 58 fixed to the pulleys 55 and 56 can be expanded, and the range of operation when power is transmitted by the belt member 68 fixed to the pulleys 65 and 66 can be expanded.

[0037] The pulley 57, acting as an intermediate pulley, is positioned such that, when viewed from the direction in which the rotation axes of the drive pulley 55 and the driven pulley 56 extend, at least a portion of it is closer to the center line L2 connecting the rotation axis of pulley 55 and the rotation axis of pulley 56 than to the common external tangent line L1 between pulley 55 and pulley 56. This allows the belt member 58 to be easily pressed against pulley 55 and pulley 56 in the direction of wrapping by the pulley 57, which is positioned closer to the center line L2 than the common external tangent line L1 between pulley 55 and pulley 56. Therefore, the range of movement of the belt member 58 when rotating pulley 55 can be easily expanded, and thus the range of operation when power is transmitted by the belt member 58 can be easily expanded.

[0038] The belt member 58 includes a straight portion 58a that extends linearly from the pulley 55 as a driving pulley to the pulley 56 as a driven pulley, and a bent portion 58b that extends from the pulley 55 to the pulley 56 while being pressed by the pulley 57 as an intermediate pulley. Further, the belt member 58 is wound around the pulley 55 and the pulley 56 in an annular shape by fixing the straight portion 58a and the bent portion 58b to the pulley 55 and the pulley 56, respectively. Here, when an intermediate pulley is arranged on each of one side and the other side of the belt member 58 wound around the pulley 55 and the pulley 56, the belt member 58 is constituted by a pair of bent portions against which the intermediate pulley is pressed on each. In that case, since it is necessary to arrange two or more intermediate pulleys, the number of parts increases. Further, since it is necessary to arrange the belt member 58 so that the pair of bent portions do not contact each other, it is considered that the work of adjusting the pressing amount when pressing the belt member 58 becomes a burden on the operator. Considering this, in the present embodiment, the belt member 58 includes a straight portion 58a that extends linearly from the pulley 55 to the pulley 56, and a bent portion 58b that extends from the pulley 55 to the pulley 56 while being pressed by the pulley 57. Thereby, compared with the case where the belt member 58 includes a pair of bent portions, by including the straight portion 58a and the bent portion 58b in the belt member 58, an increase in the number of parts can be suppressed, and an increase in the burden of the adjustment work of the arrangement of the belt member 58 can be suppressed.

[0039] The straight portion 58a and the bent portion 58b of the belt member 58 are arranged at the same height position with respect to each other in the direction in which the rotation axes of the pulley 55 as a driving pulley and the pulley 56 as a driven pulley extend. Thereby, compared with the case where the straight portion 58a and the bent portion 58b of the belt member 58 are arranged at different height positions with respect to each other, the size in the height direction of the robot arm 10 on which the belt member 58 is arranged can be reduced.

[0040] The belt member 58 has a drive winding portion 58c that is wrapped around the pulley 55 as the pulley 55 moves as the pulley 55 moves, and a driven winding portion 58d that is wrapped around the pulley 56 as the driven pulley moves. The pulley 57 as an intermediate pulley is positioned so that it does not come into contact with the drive winding portion 58c and the driven winding portion 58d even when the belt member 58 moves as the pulley 55 moves. Here, the portion of the belt member 58 that is pressed against by the pulley 57 curves in the opposite direction to the curvature of the drive winding portion 58c wrapped around the pulley 55 or the driven winding portion 58d wrapped around the pulley 56. Therefore, if the drive winding portion 58c or the driven winding portion 58d moves to a position where it comes into contact with the pulley 57 as the pulley 55 moves, the same portion of the belt member 58 will be curved on both the front and back sides. In that case, the fatigue accumulated in the belt member 58 due to the curvature increases, leading to a higher frequency of replacement of the belt member 58. In contrast, in this embodiment, the pulley 57 is positioned so that it does not come into contact with the drive winding portion 58c and the driven winding portion 58d even when the belt member 58 moves in conjunction with the operation of the pulley 55. This prevents the belt member 58 from being curved on both the front and back sides, thus preventing an increase in the frequency of replacement of the belt member 58.

[0041] The robot 100 is equipped with an adjustment mechanism 59 for adjusting the position of a pulley 57, which acts as an intermediate pulley. By adjusting the position of the pulley 57 using the adjustment mechanism 59, the pulley 57 also functions as a tensioner for adjusting the tension of the belt member 58. As a result, by having the pulley 57 also function as a tensioner for adjusting the tension of the belt member 58, the complexity of the device configuration can be suppressed compared to a case where a separate tensioner for adjusting the tension of the belt member 58 is provided in addition to the pulley 57.

[0042] Pulley 55 as the driving pulley and pulley 56 as the driven pulley have outer diameters of different sizes. Thereby, even when pulley 55 and pulley 56 have outer diameters of different sizes, by arranging pulley 57 as the intermediate pulley that presses the belt member 58, the movement range of the belt member 58 can be set to correspond to the size of the outer diameter of each of pulley 55 and pulley 56. Therefore, even when pulley 55 and pulley 56 have outer diameters of different sizes, the operating range can be expanded.

[0043] Pulley 57 as the intermediate pulley is arranged closer to the one with the smaller outer diameter among pulley 55 as the driving pulley and pulley 56 as the driven pulley inside the robot arm 10. Thereby, since pulley 57 is arranged closer to the one with the smaller outer diameter among pulley 55 and pulley 56, the belt member 58 can be pressed more against the one with the smaller outer diameter among pulley 55 and pulley 56. Therefore, even when pulley 55 and pulley 56 have outer diameters of different sizes, the difference between the length of the portion of the belt member 58 wound around pulley 55 and the length of the portion wound around pulley 56 can be reduced. As a result, even when pulley 55 and pulley 56 have outer diameters of different sizes, the operating range can be effectively expanded.

[0044] When viewed from the direction in which the rotation axes of pulley 55 as the driving pulley and pulley 56 as the driven pulley extend, the center 57c of pulley 57 is arranged at a position shifted in the pressing direction P for pressing the belt member 58 from the center straight line L2 connecting the position of the rotation axis of pulley 55 and the position of the rotation axis of pulley 56. Thereby, by arranging the center 57c of pulley 57 at a position shifted in the pressing direction P from the center straight line L2, the pressing amount of the belt member 58 by pulley 57 can be made even larger. As a result, the operating range when power is transmitted by the belt member 58 can be further expanded.

[0045] The pulley 57, acting as an intermediate pulley, has an outer diameter smaller than that of the drive pulley 55 and smaller than that of the driven pulley 56. This reduces the area occupied by the pulley 57 for pressing the belt member 58 on the robot arm 10 compared to the case where the pulley 57 has a larger outer diameter than the pulleys 55 and 56. Therefore, it is possible to suppress an increase in the size of the robot arm 10 on which the pulleys 55, 56, and 57 are located.

[0046] The robot arm 10 includes a base link 11 and an end link 12 that rotate relative to each other along the horizontal direction. The robot arm 20 includes a base link 21 and an end link 22 that rotate relative to each other along the horizontal direction. The pulleys 55 and 65 as drive pulleys, the pulleys 56 and 66 as driven pulleys, the belt members 58 and 68, and the pulleys 57 and 67 as intermediate pulleys are respectively located inside the end links 12 and 22 of the robot arms 10 and 20. This effectively expands the operating range of the robot arms 10 and 20, or the operating range of the hands 30 and 40 as end effectors located at the ends of the robot arms 10 and 20, by positioning the pulleys 57 and 67 as intermediate pulleys that press the belt members 58 and 68 inside the end links 12 and 22 when the robot arms 10 and 20 are operated along the horizontal direction.

[0047] The robot 100 includes hands 30 and 40, which are attached to the ends of the end links 12 and 22, respectively. Hands 30 and 40 are operated by the rotation of pulleys 56 and 66, respectively, which act as driven pulleys. By arranging pulleys 57 and 67, respectively, as intermediate pulleys that press belt members 58 and 68 inside the end links 12 and 22, the operating range of the pulleys 56 and 66 positioned on the end links 12 and 22 can be expanded. Therefore, by arranging pulleys 57 and 67, the operating range of hands 30 and 40, which are operated by the rotation of pulleys 56 and 66, can be effectively expanded.

[0048] The robot 100 is equipped with hands 30 and 40, which are attached to robot arms 10 and 20 and serve as substrate holding hands for holding a workpiece W as a substrate. Hands 30 and 40, as substrate holding hands, operate by the rotation of pulleys 56 and 66, which serve as driven pulleys. This allows the operating range of the drive pulleys 55 and 65 and the driven pulleys 56 and 66 to be expanded by arranging pulleys 57 and 67, which serve as intermediate pulleys that press against the belt members 58 and 68, even when transporting a substrate held by hands 30 and 40. Therefore, by arranging pulleys 57 and 67, the operating range of hands 30 and 40 can be expanded when transporting a substrate held by hands 30 and 40, effectively expanding the operating range of the transport operation.

[0049] The robot 100 includes a base 90 that supports the robot arms 10 and 20. The drive units 71, 72, and 73 are located inside the base 90. This allows the robot arms 10 and 20 to be made smaller compared to when the drive units 71, 72, and 73 are located inside the robot arms 10 and 20, thereby suppressing physical interference between the robot arms 10 and 20 and externally located components. Furthermore, by providing pulleys 57 and 67 as intermediate pulleys, the operating range when power is transmitted by belt members 58 and 68 can be effectively expanded, even when the drive units 71, 72, and 73 are located inside the base 90.

[0050] [Variations] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the description of the embodiments above, and further includes all modifications (variations) within the meaning and scope equivalent to the claims.

[0051] For example, in the above embodiment, the hands 30 and 40, which serve as substrate holding hands, are shown to hold a workpiece W which is a disc-shaped substrate, but the disclosure is not limited to this. In the disclosure, the workpiece may be a jig that mimics a disc-shaped substrate. Alternatively, the workpiece may be a plate-shaped member having a shape other than a disc, such as a rectangle. Furthermore, the hands may be configured to hold a workpiece that is not a plate-shaped substrate.

[0052] Furthermore, in the above embodiment, an example was shown in which a pulley 57 is arranged as an intermediate pulley in the tip link 12 of the robot arm 10, and the belt member 58 has a straight portion 58a and a bent portion 58b, but the present disclosure is not limited to this. In the present disclosure, by arranging multiple intermediate pulleys, the belt member may not have a straight portion but have a pair of bent portions. Alternatively, multiple intermediate pulleys may be pressed against a single bent portion.

[0053] Furthermore, although the above embodiment shows an example in which a belt member 58, which is a single strip-shaped member, is wrapped around a pulley 55 as a drive pulley and a pulley 56 as a driven pulley in an annular shape, the present disclosure is not limited to this. In the present disclosure, the straight portion and the bent portion of the belt member may be made into separate members so that they are wrapped around the drive pulley and the driven pulley in an annular shape.

[0054] Furthermore, in the above embodiment, an example was shown in which the straight portion 58a and the bent portion 58b of the belt member 58 are positioned at the same height relative to each other in the direction in which the respective rotation axes of the drive pulley pulley 55 and the driven pulley pulley 56 extend. However, the present disclosure is not limited to this. In the present disclosure, the straight portion and the bent portion of the belt member may be positioned at different height relative to each other.

[0055] Furthermore, in the above embodiment, an example was shown in which the pulley 57, acting as an intermediate pulley, is positioned so as not to come into contact with the drive winding portion 58c and the driven winding portion 58d even when the belt member 58 moves in conjunction with the operation of the pulley 55. However, the present disclosure is not limited to this. In the present disclosure, the intermediate pulley may be positioned to come into contact with the drive winding portion, or it may be positioned to come into contact with the driven winding portion.

[0056] Furthermore, in the above embodiment, an example was shown in which the pulley 57, which serves as an intermediate pulley, also functions as a tensioner for adjusting the tension of the belt member 58 by adjusting its position with an adjustment mechanism 59. However, the present disclosure is not limited to this. In this disclosure, a tensioner for adjusting the tension of the belt member may be provided separately from the intermediate pulley.

[0057] Furthermore, although the above embodiment shows an example in which the outer diameter of the pulley 55, which serves as the drive pulley, is smaller than the outer diameter of the pulley 56, which serves as the driven pulley, the present disclosure is not limited to this. In this disclosure, the outer diameter of the drive pulley may be larger than the outer diameter of the driven pulley. Alternatively, the outer diameters of the drive pulley and the driven pulley may be the same size.

[0058] Furthermore, in the above embodiment, an example was shown in which the pulley 57, which serves as an intermediate pulley, is positioned closer to the pulley 55, which has a smaller outer diameter, among the drive pulley 55 and the driven pulley 56. However, the present disclosure is not limited to this. In the present disclosure, the intermediate pulley may be positioned closer to the drive pulley or the driven pulley with the larger outer diameter. Alternatively, the intermediate pulley may be positioned between the drive pulley and the driven pulley.

[0059] Also, in the above embodiment, an example is shown in which the center 57c of the pulley 57 as the intermediate pulley is arranged at a position shifted in the pressing direction P for pressing the belt member 58 from the center line L2 connecting the position of the rotation axis of the pulley 55 as the driving pulley and the position of the rotation axis of the pulley 56 as the driven pulley, when viewed from the direction in which the rotation axes of the pulley 55 as the driving pulley and the pulley 56 as the driven pulley extend. However, the present disclosure is not limited to this. In the present disclosure, when pressing the belt member along the pressing direction, the center of the intermediate pulley may be arranged on the front side in the pressing direction from the center line. Also, the center of the intermediate pulley may be arranged on the center line.

[0060] Also, in the above embodiment, an example is shown in which the pulley 57 as the intermediate pulley has an outer diameter smaller than the outer diameter of the pulley 55 as the driving pulley and smaller than the outer diameter of the pulley 56 as the driven pulley. However, the present disclosure is not limited to this. In the present disclosure, the outer diameter of the intermediate pulley may be larger than the outer diameter of the driving pulley or may be larger than the outer diameter of the driven pulley.

[0061] Also, in the above embodiment, an example is shown in which the hands 30 and 40 are operated by the rotation of the pulleys 56 and 66 as the driven pulleys. However, the present disclosure is not limited to this. In the present disclosure, the robot arm may be operated by the rotation of the driven pulley. For example, the driving pulley, the driven pulley, the belt member, and the intermediate pulley may be arranged inside the base end link arranged on the base end side.

[0062] Also, in the above embodiment, the robot 100 －１ Pa to 10 －５ Pa in a vacuum environment, and an example is shown in which the arm spaces inside the robot arms 10 and 20 are in a high vacuum with the same pressure as the outside. However, the present disclosure is not limited to this. In the present disclosure, the robot may be arranged in an ultra-high vacuum environment with a pressure lower than 10 －５ Pa, or may be arranged in a medium vacuum with a pressure higher than 10 －１ Pa and up to 10 ２ Pa, or may be arranged in a low vacuum from 10 －１ Pa to 10 ５ Pa and up to 10 ２The robot may be placed in a low vacuum environment down to Pa. Alternatively, the robot may be placed in a non-vacuum environment. Furthermore, the arm space may be filled with a gas at a different pressure than the space in which the robot is placed. For example, if the robot is placed in a vacuum environment, the arm space may be an airtight space, 10 ５ The space may be filled with air at atmospheric pressure of approximately Pa. In other words, the robot arm may be placed in a space with a lower pressure than the arm space. Also, the arm space may be 10 ５ The space may be filled with a gas at a pressure higher than atmospheric pressure (around Pa), or with a gas at a pressure lower than atmospheric pressure. Furthermore, the interior of the arm space may be filled with a gas other than air, such as nitrogen or carbon dioxide. Also, the pressure outside the arm space may be higher than the pressure inside.

[0063] Furthermore, while the first and second embodiments described above show examples in which the hands 30 and 40 include a bifurcated plate-shaped blade member, the present disclosure is not limited thereto. In this disclosure, the blade member of the hand does not have to be bifurcated. The blade member may be a rectangular plate. Also, the blade member may be branched into three or more parts. Also, multiple blade members may be arranged in a single hand. Also, by arranging a chuck portion for fixing a workpiece in the hand, it may be made into an active type hand.

[0064] Furthermore, although the above embodiment shows an example in which the robot 100 is a dual-arm transport robot equipped with a pair of robot arms 10 and 20, the disclosure is not limited thereto. In this disclosure, the robot may be equipped with only one robot arm, or it may be equipped with three or more robot arms. Also, multiple hands may be attached to one robot arm. Moreover, the robot does not have to be a transport robot. That is, the end effector attached to the tip of the robot arm does not have to be a hand that holds a workpiece. For example, an end effector that performs processing or painting on a workpiece may be attached to the robot arm.

[0065] Furthermore, although the above embodiments show examples in which the robot arms 10 and 20 are horizontally articulated, this disclosure is not limited thereto. In this disclosure, the robot arms may have configurations other than horizontally articulated, such as vertically articulated.

[0066] Furthermore, while the above embodiments show examples in which the elbow joint and wrist joint of the robot arms 10 and 20 are controlled in conjunction, this disclosure is not limited to this. In this disclosure, each of the multiple joints in the robot arm may be controlled independently.

[0067] Furthermore, while the above embodiment shows an example in which a pair of robot arms 10 and 20 have a common structure, and a pair of hands 30 and 40 have a common structure, the disclosure is not limited to this. In this disclosure, a pair of robot arms may have different structures. Also, a pair of hands may have different structures.

[0068] Furthermore, in the above embodiment, an example was shown in which a drive unit 71 for driving the elbow joint and wrist joint of the robot arm 10, a drive unit 72 for driving the elbow joint and wrist joint of the robot arm 20, and a drive unit 73 for driving the shoulder joints of the robot arm 10 and the robot arm 20 are arranged inside the base unit 90, but the present disclosure is not limited to this. In this disclosure, the drive unit that serves as the drive source for rotating the drive pulley may be arranged inside the robot arm. Also, if there are multiple drive units that serve as drive sources for rotating the drive pulley in the robot, some of the multiple drive units may be arranged inside the base unit.

[0069] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0070] [Embodiments] The exemplary embodiments described above will be understood by those skilled in the art to be specific examples of the following embodiments.

[0071] (Aspect 1) A robot comprising: a robot arm; a drive pulley disposed inside the robot arm; a driven pulley disposed inside the robot arm separately from the drive pulley; a drive unit that serves as a drive source for rotating the drive pulley; a belt member fixed to each of the drive pulley and the driven pulley, which transmits power from the drive pulley to the driven pulley; and at least one intermediate pulley disposed between the drive pulley and the driven pulley, which presses the belt member in a direction that wraps around each of the drive pulley and the driven pulley.

[0072] (Aspect 2) The robot according to aspect 1, wherein, when viewed from the direction in which the rotation axes of the drive pulley and the driven pulley extend, at least a portion of the intermediate pulley is positioned closer to the center line connecting the position of the rotation axis of the drive pulley and the position of the rotation axis of the driven pulley than the common outer tangent line between the drive pulley and the driven pulley.

[0073] (Aspect 3) The robot according to aspect 1 or aspect 2, wherein the belt member includes a straight portion extending linearly from the drive pulley to the driven pulley and a bent portion extending from the drive pulley to the driven pulley while being pressed by the intermediate pulley, and the straight portion and the bent portion are fixed to the drive pulley and the driven pulley respectively, so that the belt is wrapped around the drive pulley and the driven pulley in an annular shape.

[0074] (Aspect 4) The robot according to aspect 3, wherein the straight portion and the bent portion of the belt member are positioned at the same height relative to each other in the direction in which the respective rotation axes of the drive pulley and the driven pulley extend.

[0075] (Aspect 5) The robot according to any one of aspects 1 to 4, wherein the belt member has a drive winding portion that is wrapped around the drive pulley in accordance with the operation of the drive pulley and a driven winding portion that is wrapped around the driven pulley, and the intermediate pulley is positioned so as not to come into contact with the drive winding portion and the driven winding portion even when the belt member moves in accordance with the operation of the drive pulley.

[0076] (Aspect 6) The robot according to any one of aspects 1 to 5, further comprising an adjustment mechanism for adjusting the position of the intermediate pulley, wherein the intermediate pulley also serves as a tensioner for adjusting the tension of the belt member by adjusting its position by the adjustment mechanism.

[0077] (Aspect 7) The robot according to any one of aspects 1 to 6, wherein the drive pulley and the driven pulley have outer diameters of different sizes from each other.

[0078] (Aspect 8) The robot according to aspect 7, wherein the intermediate pulley is positioned inside the robot arm toward the one with the smaller outer diameter of the drive pulley and the driven pulley.

[0079] (Aspect 9) The robot according to aspect 2, wherein the center of the intermediate pulley is located at a position offset in the pressing direction for pressing the belt member, from the center line connecting the position of the rotation axis of the drive pulley and the position of the rotation axis of the driven pulley, when viewed from the direction in which the rotation axes of the drive pulley and the driven pulley extend.

[0080] (Aspect 10) The robot according to any one of aspects 1 to 9, wherein the intermediate pulley has an outer diameter smaller than the outer diameter of the drive pulley and smaller than the outer diameter of the driven pulley.

[0081] (Aspect 11) The robot according to any one of aspects 1 to 10, wherein the robot arm includes a base link and an end link that rotate relative to each other along the horizontal direction, and the drive pulley, the driven pulley, the belt member, and the intermediate pulley are arranged inside the end link of the robot arm.

[0082] (Aspect 12) The robot according to aspect 11, further comprising a hand attached to the tip of the tip link, wherein the hand operates by the rotation of the driven pulley.

[0083] (Aspect 13) The robot according to any one of aspects 1 to 12, further comprising a substrate holding hand attached to the robot arm for holding a substrate, wherein the substrate holding hand is operated by the rotation of the driven pulley.

[0084] (Aspect 14) The robot according to any one of aspects 1 to 13, further comprising a base portion that supports the robot arm, wherein the drive unit is disposed inside the base portion.

[0085] 10, 20 Robot arm 11, 21 Base link 12, 22 Tip link 30, 40 Hand (substrate holding hand) 55, 65 Pulley (drive pulley) 56, 66 Pulley (driven pulley) 57, 67 Pulley (intermediate pulley) 58, 68 Belt member 59 Adjustment mechanism 71, 72 Drive unit 80 Control unit 90 Base unit 100 Robot

Claims

1. A robot comprising: a robot arm; a drive pulley disposed inside the robot arm; a driven pulley disposed inside the robot arm separately from the drive pulley; a drive unit that serves as a drive source for rotating the drive pulley; a belt member fixed to each of the drive pulley and the driven pulley, which transmits power from the drive pulley to the driven pulley; and at least one intermediate pulley disposed between the drive pulley and the driven pulley, which presses the belt member in a direction that wraps around each of the drive pulley and the driven pulley.

2. The robot according to claim 1, wherein, when viewed from the direction in which the rotation axes of the drive pulley and the driven pulley extend, at least a portion of the intermediate pulley is positioned closer to the center line connecting the position of the rotation axis of the drive pulley and the position of the rotation axis of the driven pulley than the common outer tangent line between the drive pulley and the driven pulley.

3. The robot according to claim 1, wherein the belt member includes a straight portion extending linearly from the drive pulley to the driven pulley and a bent portion extending from the drive pulley to the driven pulley while being pressed by the intermediate pulley, and the straight portion and the bent portion are fixed to the drive pulley and the driven pulley respectively, so that the belt is wrapped around the drive pulley and the driven pulley in an annular shape.

4. The robot according to claim 3, wherein the straight portion and the bent portion of the belt member are positioned at the same height relative to each other in the direction in which the respective rotation axes of the drive pulley and the driven pulley extend.

5. The robot according to claim 1, wherein the belt member has a drive winding portion that is wrapped around the drive pulley in accordance with the operation of the drive pulley and a driven winding portion that is wrapped around the driven pulley, and the intermediate pulley is positioned so as not to come into contact with the drive winding portion and the driven winding portion even when the belt member moves in accordance with the operation of the drive pulley.

6. The robot according to claim 1, further comprising an adjustment mechanism for adjusting the position of the intermediate pulley, wherein the intermediate pulley also functions as a tensioner for adjusting the tension of the belt member when its position is adjusted by the adjustment mechanism.

7. The robot according to claim 1, wherein the drive pulley and the driven pulley have outer diameters of different sizes from each other.

8. The robot according to claim 7, wherein the intermediate pulley is positioned inside the robot arm toward the one with the smaller outer diameter of the drive pulley and the driven pulley.

9. The robot according to claim 2, wherein the center of the intermediate pulley is positioned in the pressing direction that presses the belt member, with respect to the direction in which the rotation axes of the drive pulley and the driven pulley extend, and is offset from the center line connecting the position of the rotation axis of the drive pulley and the position of the rotation axis of the driven pulley.

10. The robot according to claim 1, wherein the intermediate pulley has an outer diameter smaller than the outer diameter of the drive pulley and smaller than the outer diameter of the driven pulley.

11. The robot arm includes a base link and an end link that rotate relative to each other along the horizontal direction, and the drive pulley, the driven pulley, the belt member, and the intermediate pulley are located inside the end link of the robot arm, according to claim 1.

12. The robot according to claim 11, further comprising a hand attached to the tip of the tip link, wherein the hand is operated by the rotation of the driven pulley.

13. The robot according to claim 1, further comprising a substrate holding hand attached to the robot arm for holding a substrate, wherein the substrate holding hand is operated by the rotation of the driven pulley.

14. The robot according to claim 1, further comprising a base portion for supporting the robot arm, wherein the drive unit is disposed inside the base portion.

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