JP7191564B2 - industrial robot - Google Patents

Description

The present invention relates to an industrial robot that transports objects such as semiconductor wafers.

The industrial robot described in Patent Document 1 is a robot that transports semiconductor wafers, and is used by being incorporated in a semiconductor manufacturing system. 2. Description of the Related Art A semiconductor manufacturing system is provided with a cassette in which a plurality of semiconductor wafers are housed while being separated from each other in the vertical direction, and a processing device for performing processing such as etching on the semiconductor wafers. The semiconductor wafers are taken out in order, and the taken out semiconductor wafers are transferred to the processing equipment. This robot includes a hand on which a semiconductor wafer is placed, an arm that moves the hand in a horizontal plane, and an elevating mechanism that elevates an arm support member.

JP 2017-127956 A

A ball screw mechanism, for example, is used as an elevating mechanism for elevating the arm support member. It has an output pulley attached to the shaft and a belt stretched between the input pulley and the output pulley. Rotation of the motor is appropriately decelerated between the input pulley and the output pulley and transmitted to the screw shaft. Depending on the number of revolutions of the motor, etc., the output pulley may have a relatively large diameter in order to obtain the required reduction ratio. In this case, there is a possibility that the installation area required for installation of the robot will increase.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an industrial robot capable of reducing the installation area.

An industrial robot according to one aspect of the present invention includes a hand that holds an object to be transported, an arm that moves the hand in a horizontal plane, an arm support that rotatably supports the arm, and the arm support. an elevating mechanism for elevating the elevating mechanism, the elevating mechanism including a feed screw shaft and a strut supporting the feed screw shaft, a linear motion guide extending vertically, a motor, and rotating the motor a rotation transmission mechanism for transmitting power to the feed screw shaft, the rotation transmission mechanism including an input rotary member rotated by the motor, an output rotary member attached to the lower end of the feed screw shaft, and an input side. and at least one intermediate rotary member for reducing rotation transmitted from the input rotary member to the output rotary member, the linear motion guide and the When the output rotary member is viewed in the vertical direction, the output rotary member is provided within a guide area covered by the linear motion guide, and the arm extends vertically through the base end of the arm. The arm is rotatable about an extending rotating shaft, and is bendable and stretchable so as to move the hand forward and backward in a radial direction about the rotating shaft, and can rotate around the rotating shaft in a bent state. In a rectangular area that includes the movement area of the arm and the hand and the guide area, the guide area is arranged outside the movement area at a corner of the rectangular area. .

ADVANTAGE OF THE INVENTION According to this invention, the industrial robot which can make an installation area small can be provided.

It is a front view of an example of an industrial robot for describing an embodiment of the present invention. FIG. 2 is a plan view of the industrial robot of FIG. 1; FIG. 2 is a schematic diagram showing an example of the motion of the industrial robot in FIG. 1; FIG. 2 is a schematic diagram showing an example of the motion of the industrial robot in FIG. 1; FIG. 2 is a schematic diagram showing an example of the motion of the industrial robot in FIG. 1; FIG. 2 is a schematic diagram showing an example of the motion 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 of 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 describing embodiments of the present invention. An industrial robot 1 (hereinafter referred to as "robot 1") is a horizontal articulated robot for transporting a semiconductor wafer 2 as an object to be transported. 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 elevates the arm 20 .

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, edge gripping, suction, or the like, or may simply be placed 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 portion 21 and a second arm portion 22 . A distal end portion of the first arm portion 21 supports the hand 10 so as to be rotatable in a horizontal plane. The distal end portion of the second arm portion 22 supports the proximal end portion of the first arm portion 21 so as to be rotatable in the horizontal plane. A proximal end portion of the second arm portion 22 is supported by an arm support portion 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 portion 22 , and the first arm portion 21 is rotated with respect to the second arm portion 22 . , and the rotation of the hand 10 with respect to the first arm portion 21, the hand 10 can be bent and stretched so as to move forward and backward in the radial direction about the rotation axis z. The arm support section 23 is provided with a motor for rotating the second arm section 22 , a motor for rotating the first arm section 21 , and a motor for rotating the hand 10 .

The lifting mechanism 30 has a linear motion guide 31 , and the linear motion guide 31 includes a feed screw shaft 32 , a strut portion 33 and a pair of guide rails 34 . The feed screw shaft 32 is arranged to extend in the vertical direction Z. As shown in FIG. The strut portion 33 is arranged to extend in the vertical direction Z in parallel with the feed screw shaft 32 and supports the feed screw shaft 32 rotatably. 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 portion 33 . The arm support portion 23 is provided with a nut member 24 screwed onto the feed screw shaft 32 and a pair of sliders 25 engaged with the pair of guide rails 34 . The arm support portion 23 is vertically moved along the feed screw shaft 32 as the feed screw shaft 32 rotates.

The lifting mechanism 30 further has a motor 35 and a rotation transmission mechanism. A base portion 36 is provided at the lower end portion of the strut portion 33 , and the motor 35 and the rotation transmission mechanism are assembled to the base portion 36 . The rotation of the motor 35 is decelerated 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 portion 23 is vertically moved along the feed screw shaft 32, and the arm 20 is lifted. The motor 35 is arranged out of the lower side of the arm support portion 23 so as not to interfere with the arm support portion 23 that moves up and down. The rotation transmission mechanism will be described later.

(Operation of industrial robot)
3A-3D show the motion of the robot 1. FIG. The robot 1 is used by being incorporated in a semiconductor manufacturing system. A semiconductor manufacturing system is provided with a cassette 3 in which a plurality of wafers 2 are accommodated while being spaced apart in the vertical direction Z, and a processing apparatus 4 for performing processing such as etching on the wafers 2 . In this example, the cassette 3 is arranged adjacent to the robot 1 in a horizontal plane in a first direction X, and the processing device 4 is arranged in a horizontal plane in a second direction Y substantially perpendicular to the first direction. are placed 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 wafer 2 to be transferred among the plurality of wafers 2 accommodated in the cassette 3. As shown in FIG. 20 is raised and lowered. Then, the robot 1 extends the arm 20 along the first direction X and holds the wafer 2 accommodated in the cassette 3 by the hand 10 . After holding the wafer 2 by the hand 10, the robot 1 bends the arm 20 and takes out the wafer 2 from the cassette 3, as shown in FIG. 3B.

Next, as shown in FIG. 3C , the robot 1 rotates the arm 20 about the rotation axis z by approximately 90° while the arm 20 is bent, and directs the hand 10 toward the processing device 4 . Then, the robot 1 drives the motor 35 to rotate the feed screw shaft 32 and raises and lowers the arm 20 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 transfers the wafer 2 held by the hand 10 to the processing device 4 .

(Structure of Rotation Transmission Mechanism)
4 and 5 show a configuration example of a rotation transmission mechanism that transmits rotation of the motor 35 to the feed screw shaft 32. FIG. The rotation transmission mechanism 40 shown in FIGS. 4 and 5 has an input pulley 41 as an input rotation member, a relay pulley 42 as a relay rotation member, and an output pulley 43 as an output rotation member. The input pulley 41 is attached to the rotating shaft 37 of the motor 35 and rotated by the motor 35 . The output pulley 43 is attached to the lower end of the feed screw shaft 32 . The relay pulley 42 is rotatably supported by a rotating shaft 44 rotatably supported by the base portion 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 the rotary shaft 44 and rotates together with the rotary shaft 44 . Furthermore, 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 .

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, causing the output pulley 43 to rotate. Then, the feed screw shaft 32 is rotated integrally with the output pulley 43 . In the above rotation transmission, the relay pulley 42 decelerates and transmits the rotation from the input side to the output side based on the difference in peripheral speed between the large diameter portion 45 and the small diameter portion 46 that rotate together.

A plurality of relay pulleys 42 may be provided in order to obtain a desired speed reduction ratio, but there is concern about an increase in transmission loss as the number of relay pulleys 42 increases. 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 decreasing the diameter of the small diameter portion 46 . From the viewpoint of increasing the speed reduction ratio, as shown in FIG. Based on this, the speed reduction ratio can be increased. Also, 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 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, a movement area A is defined as an area where the hand 10 and the arm 20 move when the bent arm 20 is rotated around the rotation axis z. , 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 arranged outside the movement area A. Interference between the arm 20 and the linear motion guide 31 is avoided. The rectangular area C is an area including the moving area A and the guide area B, and the guide area B is arranged outside the moving area A at the corner of the rectangular area C. As shown in FIG. The area of this rectangular area C can be said to be the minimum installation area required for installation of the robot 1 .

Since the rotation transmitted to the output pulley 43 is decelerated by the relay pulley 42, the diameter of the output pulley 43 can be reduced, and the output pulley 43 can be accommodated within the guide region B. The output pulley 43 that fits within the guide area B also fits within the rectangular area C that includes the guide area B. As shown in FIG. If the rotation of the input pulley 41 is directly transmitted to the output pulley 43, the output pulley 43 must have a larger diameter than the input pulley 41 in order to decelerate the rotation transmitted to the output pulley 43. 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 also protrude outside the rectangular area C to increase the installation area of the robot 1 . By reducing the rotation of the motor 35 by the intermediate pulley 42 in this manner, the diameter of the output pulley 43 is reduced, and the output pulley 43 is accommodated within the guide area B, so that the installation area of the robot 1 can be reduced.

In this example, the guide area B is arranged outside the movement area A at the corner of the rectangular area C, and the space utilization efficiency is excellent. As a result, the guide area B can be made as large as possible within the rectangular area C that provides the minimum installation area for the robot 1, and when the output pulley 43 is accommodated within the guide area B, the output pulley 43 can be designed more freely. be done. For example, the output pulley 43 can be made larger in diameter than the small diameter portion 46 of the relay pulley 42 to increase the reduction ratio. In addition, it becomes possible to install the robot 1 in one of the four corners of the conventional semiconductor manufacturing system, which has been a dead space, thereby making it possible to effectively utilize the space. This allows the semiconductor manufacturing system to be set more compactly.

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 (rotating shaft 44) is aligned with the center of the input pulley 41 (rotating shaft 37 of the motor 35). and the center of the output pulley 43 (the feed screw shaft 32). Thereby, the diameter of the large-diameter portion 45 of the relay pulley 42 can be further increased within the rectangular area C, and the reduction ratio can be further increased.

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

As described above, the industrial robot disclosed in this specification includes a hand that holds an object to be conveyed, an arm that moves the hand in a horizontal plane, and an arm support that rotatably supports the arm. and an elevating mechanism for elevating the arm support portion, the elevating mechanism including a feed screw shaft and a column portion for supporting the feed screw shaft, a linear motion guide extending in the vertical direction, a motor and a rotation transmission mechanism for transmitting rotation of the motor to the feed screw shaft, wherein the rotation transmission mechanism is attached to an input rotary member rotated by the motor and a lower end portion of the feed screw shaft. an output rotary member, an input-side large-diameter portion, and an output-side small-diameter portion, and at least one intermediate rotary member for reducing rotation transmitted from the input rotary member to the output rotary member. , When the linear motion guide and the output rotary member are viewed in the vertical direction, the output rotary member is provided within a guide area covered by the linear motion guide. According to this configuration, since the rotation of the motor is decelerated by the intermediate rotary member, it is possible to reduce the size of the output rotary member. By miniaturizing the output rotary member and placing the output rotary member in the guide area covered by the linear motion guide, the installation area of the robot can be reduced.

Further, in the industrial robot disclosed in this specification, the arm is rotatable about a rotation axis extending vertically through the base end of the arm, and and includes a movement area and a guide area for the arm and the hand when the arm is rotated around the rotation axis in a bent state. In the rectangular area, the guide areas are provided at the corners of the rectangular area. According to this configuration, 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 this specification, the input rotary member and the output rotary member are arranged along one side of the rectangular area, and the center of the relay rotary member is the input rotary member. It is arranged at a position deviated toward the center side of the moving region 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 size of the relay rotating member can be increased, and the reduction ratio can be increased. In addition, the number of speed reduction steps can be reduced, and the transmission efficiency can be improved.

Further, in the industrial robot disclosed in this specification, the large-diameter portion of the relay rotary member has a larger diameter than the input rotary member. According to this configuration, it is possible to increase the speed reduction ratio, reduce the number of stages of speed reduction, and increase the transmission efficiency.

1 industrial robot 2 semiconductor wafer (transport object)
3 Cassette 4 Processing Device 10 Hand 11 End Effector 20 Arm 21 First Arm Section 22 Second Arm Section 23 Arm Support Section 24 Nut Member 25 Slider 30 Elevating Mechanism 31 Linear Motion Guide 32 Feed Screw Shaft 33 Strut Section 34 Guide Rail 35 Motor 36 base portion 37 motor rotating shaft 40 rotation transmission mechanism 41 input pulley 42 relay pulley 43 output pulley 44 relay pulley rotating 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 (3)

a hand holding an object to be conveyed;
an arm that moves the hand in a horizontal plane;
an arm support that rotatably supports the arm;
an elevating mechanism for elevating the arm support;
with
The lifting mechanism is
a linear motion guide extending in the vertical direction, including a feed screw shaft and a strut supporting the feed screw shaft;
a motor;
a rotation transmission mechanism for transmitting rotation of the motor to the feed screw shaft;
has
The rotation transmission mechanism is
an input rotary member rotated by the motor;
an output rotary member attached to the lower end of the feed screw shaft;
at least one relay rotary member including a large-diameter portion on the input side and a small-diameter portion on the output side, for reducing rotation transmitted from the input rotary member to the output rotary member;
has
When the linear motion guide and the output rotary member are viewed in the vertical direction, the output rotary member is provided within a guide area covered by the linear motion guide ,
The arm is rotatable about a rotation shaft extending vertically through the base end of the arm, and is bendable and stretchable so as to advance and retract the hand in a radial direction about the rotation shaft. and
In a rectangular area that includes the movement area of the arm and the hand when the arm is bent and rotated around the rotation axis, and the guide area, the guide area is the rectangular area. An industrial robot positioned outside said travel area at a corner . The industrial robot according to claim 1 ,
The input rotary member and the output rotary member are arranged along one side of the rectangular area,
The industrial robot, wherein the center of the relay rotary member is located at a position deviated toward the center of the movement area with respect to a straight line connecting the center of the input rotary member and the center of the output rotary member. The industrial robot according to claim 2 ,
The industrial robot, wherein the large-diameter portion of the relay rotary member has a larger diameter than the input rotary member.

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