JP2020009818A - Industrial robot - Google Patents

Abstract

To provide an industrial robot that can reduce an installation area.SOLUTION: An industrial robot 1 includes a hand 10, an arm 20, an arm support 23, and an elevating mechanism 30, and the elevating mechanism 30 includes a feed screw shaft 32 and a support portion 33, and further a linear motion guide 31 that extends in the vertical direction, a motor 35, and a rotation transmission mechanism 40 that transmits rotation of the motor 35 to the feed screw shaft 32. The rotation transmission mechanism 40 includes an input rotation member 41 rotated by the motor 35, an output rotation member 43 attached to the lower end of the feed screw shaft 32, and at least one relay rotation member 42 that reduces the rotation transmitted from the input rotation member 41 to the output rotation member 43, and when the linear motion guide 31 and the output rotation member 43 are viewed in the vertical direction, the output rotation member 43 is provided in a guide area B covered by the linear motion guide 31.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an industrial robot for transferring a transfer target such as a semiconductor wafer.

  The industrial robot described in Patent Literature 1 is a robot that transports a semiconductor wafer, and is used by being incorporated in a semiconductor manufacturing system. The semiconductor manufacturing system is provided with a cassette in which a plurality of semiconductor wafers are housed in a vertically separated manner, and a processing device for performing processing such as etching on the semiconductor wafer. The semiconductor wafers are sequentially taken out, and the taken-out semiconductor wafers are transported to a processing apparatus. This robot includes a hand on which a semiconductor wafer is placed, an arm for moving the hand in a horizontal plane, and a lifting mechanism for lifting and lowering an arm support member.

JP-A-2017-127956

  For example, a ball screw mechanism is used as an elevating mechanism for elevating the arm support member. Such an elevating mechanism generally includes a motor, an input pulley attached to a rotating shaft of the motor, and a screw of the ball screw mechanism. An output pulley is attached to the shaft, and a belt is stretched between the input pulley and the output pulley. The rotation of the motor is appropriately decelerated between the input pulley and the output pulley and transmitted to the screw shaft. Although depending on the number of rotations of the motor, the output pulley may have a relatively large diameter in order to obtain a required reduction ratio. In this case, the installation area required for installing the robot may increase.

  The present invention has been made in view of the above circumstances, and has as its object to provide an industrial robot that can reduce the installation area.

  An industrial robot according to one embodiment of the present invention includes a hand that holds an object to be conveyed, an arm that moves the hand in a horizontal plane, an arm supporting unit that rotatably supports the arm, and the arm supporting unit. An elevating mechanism for elevating the elevating mechanism, the elevating mechanism includes a feed screw shaft, a column supporting the feed screw shaft, a linear motion guide extending vertically, a motor, and rotation of the motor. A rotation transmission mechanism for transmitting to the feed screw shaft, the rotation transmission mechanism comprising: an input rotation member rotated by the motor; an output rotation member attached to a lower end of the feed screw shaft; A large-diameter portion, including a small-diameter portion on the output side, having at least one relay rotary member for reducing the rotation transmitted from the input rotary member to the output rotary member, the linear motion guide and the output When viewed rolling member in the vertical direction, the output rotary member is disposed in the guide region covered by said linear guide.

  According to the present invention, it is possible to provide an industrial robot capable of reducing the installation area.

FIG. 1 is a front view of an example of an industrial robot for describing an embodiment of the present invention. It is a top view of the industrial robot of FIG. FIG. 2 is a schematic diagram illustrating an example of an operation of the industrial robot in FIG. 1. FIG. 2 is a schematic diagram illustrating an example of an operation of the industrial robot in FIG. 1. FIG. 2 is a schematic diagram illustrating an example of an operation of the industrial robot in FIG. 1. FIG. 2 is a schematic diagram illustrating an example of an operation of the industrial robot in FIG. 1. FIG. 2 is a front view of an example of a rotation transmission mechanism of the industrial robot in FIG. 1. FIG. 5 is a bottom view of the rotation transmission mechanism of FIG. 4.

(Overall configuration of industrial robot)
1 and 2 show an example of an industrial robot for explaining an embodiment of the present invention. The industrial robot 1 (hereinafter, referred to as “robot 1”) is a horizontal articulated robot for transferring a semiconductor wafer 2 as a transfer target. The robot 1 includes a hand 10 that holds the wafer 2, an arm 20 that moves the hand 10 in a horizontal plane, and an elevating mechanism 30 that moves the arm 20 up and down.

  The hand 10 has a flat end effector 11 on which the wafer 2 is placed. The wafer 2 may be fixed on the end effector 11 by, for example, an edge grip, suction, or the like, or may be merely mounted on the end effector 11 without being fixed. Further, the number of end effectors 11 is not limited to one, and a plurality of end effectors 11 may be provided at appropriate intervals in the vertical direction Z.

  The arm 20 has a first arm 21 and a second arm 22. The distal end of the first arm portion 21 supports the hand 10 rotatably in a horizontal plane. The distal end of the second arm 22 supports the proximal end of the first arm 21 so as to be rotatable in a horizontal plane. The base end of the second arm 22 is supported by an arm support 23 so as to be rotatable in a horizontal plane. The arm 20 is rotatable about a rotation axis z extending in the vertical direction Z through the base end of the second arm 22, and is capable of rotating the first arm 21 with respect to the second arm 22. By combining the rotation of the hand 10 with respect to the first arm portion 21, the hand 10 can be bent and extended so as to advance and retreat in the radial direction about the rotation axis z. The arm support portion 23 is provided with a motor for rotating the second arm portion 22, a motor for rotating the first arm portion 21, and a motor for rotating the hand 10.

  The elevating mechanism 30 has a linear guide 31, and the linear guide 31 includes a feed screw shaft 32, a support 33, and a pair of guide rails 34. The feed screw shaft 32 extends in the vertical direction Z. The support portion 33 extends in the vertical direction Z in parallel with the feed screw shaft 32 and rotatably supports the feed screw shaft 32. The pair of guide rails 34 are arranged so as to extend in the vertical direction Z in parallel with the feed screw shaft 32 with the feed screw shaft 32 interposed therebetween, and are fixed to the column 33. The arm support 23 is provided with a nut member 24 screwed to the feed screw shaft 32 and a pair of sliders 25 engaged with a pair of guide rails 34. The arm support 23 is moved up and down along the feed screw shaft 32 according to the rotation of the feed screw shaft 32.

  The elevating mechanism 30 further includes a motor 35 and a rotation transmission mechanism. A base 36 is provided at the lower end of the support 33, and the motor 35 and the rotation transmitting mechanism are assembled to the base 36. The rotation of the motor 35 is reduced by the rotation transmission mechanism and transmitted to the feed screw shaft 32. As a result, the feed screw shaft 32 is rotated, the arm support 23 is moved up and down along the feed screw shaft 32, and the arm 20 is moved up and down. The motor 35 is disposed so as not to interfere with the arm support 23 that is moved up and down, from below the arm support 23. The rotation transmission mechanism will be described later.

(Operation of industrial robot)
3A to 3D show the operation of the robot 1. The robot 1 is used by being incorporated into a semiconductor manufacturing system. The semiconductor manufacturing system is provided with a cassette 3 in which a plurality of wafers 2 are housed separately in the vertical direction Z, and a processing device 4 for performing processing such as etching on the wafers 2. In this example, the cassette 3 is disposed adjacent to the robot 1 in a first direction X in a horizontal plane, and the processing device 4 is configured to communicate with the robot 1 in a second direction Y in a horizontal plane substantially perpendicular to the first direction. They are arranged next to each other.

  As shown in FIG. 3A, the robot 1 drives the motor 35 to rotate the feed screw shaft 32, and moves the arm to a position corresponding to the transfer target wafer 2 among the plurality of wafers 2 stored in the cassette 3. 20 is raised and lowered. Then, the robot 1 extends the arm 20 along the first direction X, and holds the wafer 2 stored in the cassette 3 by the hand 10. After holding the wafer 2 by the hand 10, as shown in FIG. 3B, the robot 1 bends the arm 20 and takes out the wafer 2 from the cassette 3.

  Next, as shown in FIG. 3C, the robot 1 turns the arm 20 substantially 90 ° around the rotation axis z while the arm 20 is bent, and turns the hand 10 toward the processing device 4. Then, the robot 1 drives the motor 35 to rotate the feed screw shaft 32, and moves the arm 20 up and down to a position corresponding to the processing device 4. Next, as shown in FIG. 3D, the robot 1 extends the arm 20 along the second direction Y, and transports the wafer 2 held by the hand 10 to the processing device 4.

(Configuration of rotation transmission mechanism)
4 and 5 show a configuration example of a rotation transmission mechanism that transmits the rotation of the motor 35 to the feed screw shaft 32. The rotation transmission mechanism 40 shown in FIGS. 4 and 5 includes an input pulley 41 that is an input rotary member, a relay pulley 42 that is a relay rotary member, and an output pulley 43 that is an output rotary member. The input pulley 41 is attached to the rotating shaft 37 of the motor 35, and is rotated by the motor 35. The output pulley 43 is attached to a lower end of the feed screw shaft 32. The relay pulley 42 is rotatably supported by a rotation shaft 44 rotatably supported by the base 36 (see FIG. 2). The relay pulley 42 has a large-diameter portion 45 on the input side and a small-diameter portion 46 on the output side fixed to a rotating shaft 44, and rotates with the rotating shaft 44. Further, a first belt 47 is stretched between the input pulley 41 and the large diameter portion 45, and a second belt 48 is stretched between the small diameter portion 46 and the output pulley 43.

  The rotation of the input pulley 41 rotated by the motor 35 is transmitted to the large-diameter portion 45 of the relay pulley 42 via the first belt 47, and the large-diameter portion 45 is rotated. The small diameter portion 46 of the relay pulley 42 rotates integrally with the large diameter portion 45, and the rotation of the small diameter portion 46 is transmitted to the output pulley 43 via the second belt 48, and the output pulley 43 is rotated. Then, the feed screw shaft 32 is rotated integrally with the output pulley 43. In the transmission of the rotation described above, the relay pulley 42 transmits the rotation at a reduced speed from the input side to the output side based on the difference in the peripheral speed between the large-diameter portion 45 and the small-diameter portion 46 that rotate together.

  In order to obtain a desired speed reduction ratio, a plurality of relay pulleys 42 may be provided, but there is a concern that an increase in the transmission loss with an increase in the number of relay pulleys 42 may occur. Therefore, preferably, there is one relay pulley 42, and the reduction ratio is increased by increasing the diameter of the large diameter portion 45 and / or reducing the diameter of the small diameter portion 46. From the viewpoint of increasing the reduction ratio, as shown in FIG. 4, the large-diameter portion 45 may be formed to have a larger diameter than the input pulley 41, and the difference in the peripheral speed between the input pulley 41 and the large-diameter portion 45 may be reduced. Based on this, the reduction ratio can be increased. Further, the small diameter portion 46 may be formed to have a smaller diameter than the output pulley 43, and the reduction ratio can be increased based on the difference in the peripheral speed between the output pulley 43 and the small diameter portion 46.

  As shown in FIG. 5, when the robot 1 is viewed in the vertical direction Z, an area where the hand 10 and the arm 20 move when the bent arm 20 is rotated around the rotation axis z is referred to as a movement area A. The area covered by the linear motion guide 31 (the feed screw shaft 32, the support 33, and the pair of guide rails 34) is defined as a guide area B, and the guide area B is disposed outside the movement area A. Interference between the arm 20 and the linear guide 31 is avoided. The rectangular area C is an area that includes the moving area A and the guide area B, and the guide area B is disposed outside the moving area A at a corner of the rectangular area C. The area of the rectangular area C can be said to be the minimum installation area required for installing the robot 1.

  Since the rotation transmitted to the output pulley 43 is reduced by the relay pulley 42, the diameter of the output pulley 43 can be reduced, and the output pulley 43 can be accommodated in the guide area B. The output pulley 43 that fits in the guide area B also fits in the rectangular area C that includes the guide area B. If the rotation of the input pulley 41 is directly transmitted to the output pulley 43, to reduce the rotation transmitted to the output pulley 43, the output pulley 43 needs to have a larger diameter than the input pulley 41, The output pulley 43 may protrude outside the guide area B in some cases. The output pulley 43 protruding outside the guide area B can protrude outside the rectangular area C to increase the installation area of the robot 1. As described above, by reducing the rotation of the motor 35 by the relay pulley 42, the diameter of the output pulley 43 is reduced, the output pulley 43 is accommodated in the guide area B, and the installation area of the robot 1 can be reduced.

  In this example, the guide area B is disposed outside the moving area A at the corner of the rectangular area C, and the space utilization efficiency is excellent. Thereby, the guide area B can be made as large as possible in the rectangular area C that gives the minimum installation area of the robot 1, and the degree of freedom in designing the output pulley 43 is increased when the output pulley 43 is accommodated in the guide area B. Can be For example, the output pulley 43 can be made larger in diameter than the small diameter portion 46 of the relay pulley 42, and the reduction ratio can be increased. Further, the robot 1 can be installed at any one of the four corners, which has conventionally been a dead space of the semiconductor manufacturing system, and the space can be effectively used. Thus, the semiconductor manufacturing system can be set more compact.

  Preferably, the input pulley 41 and the output pulley 43 are arranged along one side of the rectangular area C, and the center of the relay pulley 42 (the rotating shaft 44) is located at the center of the input pulley 41 (the rotating shaft 37 of the motor 35). It is arranged at a position deviated toward the center (rotation axis z) of the movement area A with respect to a straight line L connecting the output pulley 43 and the center (feed screw shaft 32). Thereby, the diameter of the large diameter portion 45 of the relay pulley 42 can be further increased in the rectangular area C, and the reduction ratio can be further increased.

(Modification)
In the example described above, the pulleys 41, 42, 43 are used as the input rotary member, the output rotary member, and the relay rotary member of the rotation transmission mechanism 40, and these pulleys 41, 42, 43 are connected by belts 47, 48. However, the input rotary member, the output rotary member, and the relay rotary member are not limited to pulleys, but may be, for example, gears. When the input rotation member, the output rotation member, and the relay rotation member are configured by gears, these gears may directly mesh with each other, or may be connected by a chain or the like.

  As described above, the industrial robot disclosed in the present specification includes a hand that holds an object to be transported, an arm that moves the hand in a horizontal plane, and an arm supporting unit that rotatably supports the arm. A lifting / lowering mechanism for raising / lowering the arm support portion, wherein the lifting / lowering mechanism includes a feed screw shaft, a support portion for supporting the feed screw shaft, a linear motion guide extending in a vertical direction, and a motor. And a rotation transmitting mechanism for transmitting the rotation of the motor to the feed screw shaft. The rotation transmitting mechanism is attached to an input rotating member rotated by the motor and a lower end of the feed screw shaft. An output rotary member, including a large-diameter portion on the input side and a small-diameter portion on the output side, having at least one relay rotary member for reducing rotation transmitted from the input rotary member to the output rotary member. , When viewed serial linear guide and said output rotary member in the vertical direction, the output rotary member is disposed in the guide region covered by said linear guide. According to this configuration, the rotation of the motor is reduced by the relay rotating member, so that the output rotating member can be downsized. Then, by reducing the size of the output rotary member and by storing the output rotary member in a guide area covered by the linear motion guide, the installation area of the robot can be reduced.

  Further, in the industrial robot disclosed in the present specification, the arm is rotatable around a rotation axis extending vertically through a base end of the arm, and the arm is rotatable about the rotation axis. The arm includes a movable area and a guide area when the arm is rotated around the rotation axis in a state where the arm is bent while the arm is bent. The guide area is provided at a corner of the rectangular area. According to this configuration, the space utilization efficiency can be improved, and the guide area can be increased without increasing the installation area of the robot. Therefore, when the output rotary member is accommodated in the guide area, the degree of freedom in designing the output rotary member can be increased.

  Further, in the industrial robot disclosed in the specification, the input rotary member and the output rotary member are arranged along one side of the rectangular area, and a center of the relay rotary member is the input rotary member. It is arranged at a position deviated toward the center of the moving area with respect to a straight line connecting the center of the rotating member and the center of the output rotating member. According to this configuration, the relay rotating member can be enlarged, and the reduction ratio can be increased. Then, the transmission efficiency can be increased by reducing the number of stages of deceleration.

  In the industrial robot disclosed in the present specification, the large-diameter portion of the relay rotary member has a larger diameter than the input rotary member. According to this configuration, the reduction ratio can be increased, the number of reduction stages can be reduced, and the transmission efficiency can be increased.

1 industrial robot 2 semiconductor wafer (transfer object)
3 Cassette 4 Processing Device 10 Hand 11 End Effector 20 Arm 21 First Arm 22 Second Arm 23 Arm Support 24 Nut Member 25 Slider 30 Lifting Mechanism 31 Linear Guide 32 Feed Screw Shaft 33 Support 34 Guide Rail 35 Motor 36 base portion 37 motor rotation shaft 40 rotation transmission mechanism 41 input pulley 42 relay pulley 43 output pulley 44 relay pulley rotation shaft 45 relay pulley large diameter portion 46 relay pulley small diameter portion 47 first belt 48 second belt A movement Area B Guide area C Rectangular area L Straight line X First direction Y Second direction Z Vertical direction z Rotation axis

Claims (4)

A hand for holding an object to be conveyed,
An arm for moving the hand in a horizontal plane,
An arm supporting portion that rotatably supports the arm,
An elevating mechanism for elevating the arm support,
With
The lifting mechanism,
A linear motion guide including a feed screw shaft and a column supporting the feed screw shaft, and extending in a vertical direction;
Motor and
A rotation transmission mechanism that transmits the rotation of the motor to the feed screw shaft,
Has,
The rotation transmission mechanism,
An input rotating member rotated by the motor,
An output rotating member attached to the lower end of the feed screw shaft,
A large-diameter portion on the input side and a small-diameter portion on the output side, and at least one relay rotating member that reduces rotation transmitted from the input rotating member to the output rotating member,
Has,
An industrial robot, wherein the output rotary member is provided in a guide area covered by the linear guide when the linear guide and the output rotary member are viewed in the vertical direction. The industrial robot according to claim 1, wherein
The arm is rotatable around a rotation axis extending vertically through a base end of the arm, and is capable of bending and extending so as to advance and retreat the hand in a radial direction about the rotation axis. And
In a rectangular area including the movement area of the arm and the hand when the arm is rotated around the rotation axis in a bent state, and the guide area, the guide area is defined by the rectangular area. An industrial robot arranged at a corner outside the moving area. The industrial robot according to claim 2,
The input rotating member and the output rotating member are arranged along one side of the rectangular area,
An industrial robot, wherein the center of the relay rotating member is disposed at a position deviated toward the center of the moving area with respect to a straight line connecting the center of the input rotating member and the center of the output rotating member. The industrial robot according to claim 3, wherein
An industrial robot in which the large-diameter portion of the relay rotary member has a larger diameter than the input rotary member.

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