JP2012159200A - Power transmission mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage by the inclination of an output shaft without causing a clearance between a sealing material and the output shaft in a power transmission mechanism.SOLUTION: The power transmission mechanism 10 is composed of a base wall 6 that divides a vacuum chamber 5 that is a vacuum environment and an atmospheric environment, the output shaft 16 that is provided penetrating through the base wall 6, and a seal case 17 that freely rotatably supports the output shaft 16. The power transmission mechanism includes a first sealing material 30 that sticks and interposes between the seal case 17 and the output shaft 16, and a second sealing material 40 that sticks and interposes between the seal case 17 and the base wall 6, has elasticity in an axial direction of the output shaft 16, and follows the inclination of the output shaft 16.

Description

  The present invention includes a base wall that separates a vacuum chamber, which is a vacuum environment, from an atmospheric environment, an output shaft disposed through the base wall, and a seal case that rotatably supports the output shaft. It relates to the technology of the power transmission mechanism.

  In the process of manufacturing a semiconductor, a wiring process and a thin film forming process formed on a semiconductor wafer or a liquid crystal substrate are performed in a vacuum chamber that is a vacuum environment. The vacuum chamber is separated from the atmospheric environment by a base wall. In the vacuum chamber, the semiconductor wafer or the liquid crystal substrate is handled by a robot or a manufacturing apparatus.

  However, since a drive unit such as a robot or a manufacturing apparatus is designed to be used in an atmospheric environment, it cannot be used in a vacuum environment. Therefore, a robot or a manufacturing apparatus or the like has a driving unit such as a motor or a speed reducer arranged outside a vacuum chamber that is an atmospheric environment, and a manipulator inside the vacuum chamber that is a vacuum environment via a power transmission mechanism that penetrates the base wall. Is placed. In addition, the power transmission mechanism needs to be provided with a seal material in order to prevent inflow of air and dust from the air environment to the vacuum environment.

Patent Document 1 discloses a power transmission mechanism in which a contact-type ring-shaped sealing material is disposed between an output shaft and a housing surrounding the output shaft. Patent Document 2 discloses a power transmission mechanism that includes an annular groove-shaped gasket and a spring portion that is housed in the annular groove and is in contact with the rotating shaft.
JP 2004-84920 A JP 2004-36897 A

  When a robot arm or the like supports a heavy workpiece, the output shaft is cantilevered by the gravity of the workpiece. The power transmission devices represented by Patent Documents 1 and 2 are not arranged or designed so that the sealing material can absorb the inclination of the output shaft. At this time, due to the inclination of the output shaft, a portion where the sealing material and the output shaft are intensively pressed is generated, and the sealing material is damaged or its life is shortened. Further, since the sealing material cannot follow the output shaft due to the inclination of the output shaft, a gap is generated and a leak occurs.

At present, in order to prevent a gap due to the inclination of the output shaft, the tightening force of the sealing material on the output shaft is increased. For this reason, the seal material and the output shaft are greatly worn, and the maintenance cycle is accelerated.
Therefore, the problem to be solved is to prevent leakage in the power transmission mechanism without causing a gap between the sealing material and the output shaft due to the inclination of the output shaft.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, a base wall that divides the inside of the vacuum chamber, which is a vacuum environment, from the atmospheric environment, an output shaft disposed through the base wall, and a seal that rotatably supports the output shaft A power transmission mechanism comprising: a case; a first sealing material interposed in close contact between the seal case and the output shaft; and a close contact between a bottom surface of the seal case and an upper surface of the base wall The seal case is inclined and has an elasticity in the axial direction of the output shaft, and when the output shaft is inclined, an inclined upper surface is formed with respect to a horizontal plane formed by the lower surface by elastic deformation. A hollow cylindrical shape that follows the bottom surface of the laminated rubber, and a second rubber-sealed sealing material in which a rubber material and a metal material are laminated and the surface is covered with rubber.

  In Claim 2, The base wall which divides the inside of the vacuum chamber which is a vacuum environment, and atmospheric environment, The output shaft arrange | positioned through the said base wall, The seal case which supports the said output shaft rotatably A power transmission mechanism comprising: a first seal member closely contacted between the seal case and the output shaft; and a close contact between the bottom surface of the seal case and the top surface of the base wall. And has an elasticity in the axial direction of the output shaft, and when the output shaft is tilted, an upper surface having an inclination with respect to a horizontal plane formed by the lower surface is formed by elastic deformation, and the bottom surface of the tilted seal case And a second sealing material which is a hollow cylindrical metal expansion and contraction tube following the above.

  As effects of the present invention, the following effects can be obtained.

In the first aspect, since the second sealing material is elastic in the axial direction of the output shaft, leakage can be prevented without causing a gap between the base wall and the seal case due to the inclination of the output shaft.
Further, since the second seal material has elasticity in the axial direction of the output shaft and follows the inclination of the output shaft, the seal case is made to follow the output shaft, and the first seal material and the output shaft are intensively pressed. The portion to be reduced can be reduced, and a gap is not generated between the first seal material and the output shaft. That is, the gap between the first seal material and the output shaft caused by the inclination of the output shaft can be eliminated, and leakage can be prevented.
Moreover, since the second sealing material is a laminated rubber, the elastic force in the axial direction of the output shaft of the second sealing material can be adjusted by the spring constant.

According to the second aspect of the present invention, since the second sealing material is elastic in the axial direction of the output shaft, leakage can be prevented without causing a gap between the base wall and the seal case due to the inclination of the output shaft.
Further, since the second seal material has elasticity in the axial direction of the output shaft and follows the inclination of the output shaft, the seal case is made to follow the output shaft, and the first seal material and the output shaft are intensively pressed. The portion to be reduced can be reduced, and a gap is not generated between the first seal material and the output shaft. That is, the gap between the first seal material and the output shaft caused by the inclination of the output shaft can be eliminated, and leakage can be prevented.
Moreover, since the second seal material is a metal expansion tube, a second seal material having durability can be realized even in an environment where high temperature, corrosive gas, or the like is generated.

Next, embodiments of the invention will be described.
FIG. 1 is a partial cross-sectional configuration diagram showing the overall configuration of a robot arm including a power transmission mechanism according to the present invention, FIG. 2 is a perspective view showing the overall configuration of the second sealing material, and FIG. It is a perspective view which shows the whole structure of the 2nd sealing material.
4 is a perspective view showing the overall configuration of another second sealing material, FIG. 5 is a partial cross-sectional configuration diagram showing the overall configuration of the robot arm when the output shaft has an inclination, and FIG. It is the partial cross section block diagram which showed the whole structure of the power transmission mechanism which concerns on another Example.
FIG. 7 is a partial cross-sectional configuration diagram showing the overall configuration of the power transmission device when the output shaft has a deviation.

First, the robot arm 1 including the power transmission mechanism 10 according to the first embodiment of the present invention will be described in detail with reference to FIG.
The robot arm 1 is a device for transferring a semiconductor wafer or a liquid crystal substrate in the vacuum chamber 5. The vacuum chamber 5 is a work room in a vacuum environment that is separated from the atmospheric environment by the base wall 6. In the vacuum chamber 5, a wiring process or a thin film forming process of a semiconductor wafer or a liquid crystal substrate is performed. Further, the robot arm 1 is provided with a drive unit including a motor 11 and a speed reducer 13 in an atmospheric environment outside the vacuum chamber 5, and the arm 20 is placed in the vacuum chamber 5 via a power transmission mechanism 10 penetrating the base wall 6. Is disposed, and is supported by the base wall 6 by the support portion.

  The manipulator includes an arm 20 that rotates by driving an output shaft 16 via an arm base 19.

  The support portion includes a hollow cylindrical main body portion 15a and a flange 15 formed of an outer peripheral surface of the main body portion 15a so as to project outward, and a bottom plate 14 fixed so as to close a lower opening of the main body portion 15a. And is configured. The lower surface of the flange wall 15 b is received by the opening edge of the base wall 6 via the O-ring-shaped seal body 12.

  The power transmission mechanism 10 includes an output shaft 16 disposed through the base wall 6 to transmit the output of the speed reducer 13 to an arm 20 described later, and a hollow cylindrical seal case 17 that supports the rotation of the output shaft 16. And a hollow cylindrical first seal member 30 closely attached between the outer periphery of the output shaft 16 and the inner periphery of the seal case 17, and a hollow covering the upper surfaces of the seal case 17 and the first seal member 30 A disc-shaped seal presser 18 and a second seal member 40 interposed between the upper surface of the flange wall 15b and the lower surface of the seal case 17 are provided. The axis P is defined as the axis of the output shaft 16.

  The drive unit includes a motor 11 and a speed reducer 13 that reduces the rotational speed of the motor 11 and outputs the reduced speed. Here, the motor 11 and the speed reducer 13 are supported by the bottom plate 14 described above. The output of the motor 11 is transmitted to the output shaft 16 in the seal case 17 via the speed reducer 13 mounted on the motor 11.

Here, the 2nd sealing material 40 is demonstrated in detail using FIG. 2 to 4, only the semi-cylindrical shape is shown in the hollow cylindrical shape for easy understanding.
The second sealing material 40 is a sealing material in which a rubber material having a substantially rectangular cross section is a hollow cylinder. Further, the second sealing material 40 has elasticity with respect to the axial direction of the output shaft 16. Furthermore, the second sealing material 40 is elastically deformed so as to follow the inclination of the axis P.
Thus, since the 2nd sealing material 40 is made into a rubber material, the 2nd sealing material 40 which is a cheap and comparatively free shape is realizable.

Moreover, another 2nd sealing material 50 is demonstrated in detail using FIG.
The second sealing material 50 is a known bellows as a metal expansion and contraction tube. Similarly to the second sealing material 40, the second sealing material 50 has elasticity with respect to the axial direction of the output shaft 16 and is elastically deformed so as to follow the inclination of the axis P. Thus, since the second sealing material 50 is made of laminated rubber, the elastic force in the axial direction of the output shaft 16 of the second sealing material 50 can be adjusted by the spring constant.

Furthermore, another 2nd sealing material 60 is demonstrated in detail using FIG.
The second sealing material 60 is a sealing material in which a laminated rubber obtained by stacking rubber materials and metal materials used in the construction field and covering the surfaces with rubber is formed into a hollow cylindrical shape. Similarly to the second sealing material 40, the second sealing material 60 has elasticity with respect to the axial direction of the output shaft 16 and elastically deforms so as to follow the inclination of the axis P. As described above, since the second seal member 60 is made of a metal expansion and contraction tube, the second seal member 60 having durability can be realized even in an environment where high temperature, corrosive gas, or the like is generated.

  2 to 4, the elastic deformation following the inclination of the axis P is elastic so that the horizontal surface b formed by the upper surfaces 40b, 50b and 60b has an inclination with respect to the horizontal surface a formed by the lower surfaces 40a, 50a and 60a. Deformation means that the displacement in the axial direction of the cross section of the second sealing material 40, 50, 60 is elastically deformed while maintaining its inclination. For example, the second sealing material 40, 50, 60 is elastically deformed so that the opposite side is displaced t2 (t2> t1) with respect to the side where the displacement is t1, and an upper surface 40b having an inclination with respect to the lower surface 40a is formed. Has been. At the same time, the axial displacements t1 and t2 due to elastic deformation are elastically deformed while maintaining an inclination with respect to the axis P. In this way, the second sealing material 40, 50, 60 can follow the inclination of the axis P of the output shaft 16.

The case where the output shaft 16 has an inclination will be described in detail with reference to FIG.
For example, when the robot arm 1 supports a heavy workpiece (not shown), the output shaft 16 is in a cantilever state and has an inclination that is the axis P ′ with respect to the axis P. At this time, since the second sealing material 40 has elasticity with respect to the axial direction of the output shaft 16, a gap is formed between the upper surface of the flange wall 15 b of the flange 15 and the lower surface of the seal case 17 due to the inclination of the output shaft 16. The leakage from the atmospheric environment to the vacuum chamber 5 can be prevented without causing the above.

  In addition, since the second seal material 40 follows the inclination of the axis P of the output shaft 16, the seal case 17 is caused to follow the output shaft 16, and the portion where the first seal material 30 and the output shaft 16 are intensively pressed is formed. This can be reduced, and no gap is generated between the first seal member 30 and the output shaft 16. That is, it is possible to prevent leakage from the atmospheric environment to the vacuum chamber 5 without causing a gap between the first seal material 30 and the output shaft 16 due to the inclination of the output shaft 16.

  In other words, the second sealing material 40 synchronizes the seal case 17 with the inclination of the output shaft 16, and affects the seal mechanism constituted by the output shaft 16, the first sealing material 30, and the seal case 17 due to the inclination. No power transmission mechanism 10 is realized.

Here, the effect of the power transmission mechanism 10 will be described in comparison with the prior art.
Conventionally, the power transmission mechanism has only a seal material corresponding to the first seal material 30, and due to the inclination of the output shaft, a portion where the seal material and the output shaft are intensively pressed is generated, and the seal material There was a problem such as damage to the product or shortened life. Further, since the seal material cannot follow the output shaft due to the inclination of the output shaft, a gap is generated and a leak occurs.
In the power transmission mechanism 10 of the present invention, the second sealing material 40 seals the flange 15 and the seal case 17 with respect to the first sealing material 30, and follows the first sealing material 30 and the seal case 17 to the output shaft 16. The second sealing material 40 having a function is added. Therefore, the part which intensively press-contacts to the 1st sealing material 30 can be reduced, and the 1st sealing material 30 can be extended in life. Further, the first seal member 30 can follow the output shaft 16 due to the inclination of the output shaft 16.

  In this manner, the first sealing material 30 and the second sealing material 40 have a long life, and therefore the maintenance cycle of the robot arm 1 can be shortened. Further, since the sealing performance of the power transmission mechanism 10 is improved, it becomes possible to develop a robot for ultra-high vacuum. Furthermore, the vacuum environment of the vacuum chamber 5 can be realized with a small vacuum pump. The operations and effects described above can be similarly achieved by the second sealing material 50/60.

Furthermore, the power transmission device 90 including the power transmission mechanism 10 as another embodiment will be described in detail with reference to FIG.
The power transmission device 90 is a device for transmitting the rotational drive by the input shaft 70 in the atmospheric environment to the output shaft 80 in the vacuum chamber 5 through the power transmission mechanism 10 penetrating the base wall 6. It is supported by the base wall 6. The input shaft 70 is connected to the output shaft flange 81 via the input shaft flange 71 and transmits rotational driving to the output shaft 80. Since the power transmission mechanism 10, the vacuum chamber 5, and the support portion are the same as those of the robot arm 1, description thereof is omitted.

Here, the power transmission device 90 having a deviation in the axis P will be described in detail with reference to FIG.
For example, depending on the arrangement of the manipulator in the vacuum chamber 5 and the drive unit in the atmospheric environment, the input shaft 70 and the output shaft 80 may be displaced and fixed.
At this time, since the second sealing material 40 follows the inclination of the axis P, that is, elastically deforms while maintaining the inclination with respect to the axis P, even if the output shaft 80 is displaced, Leakage from the atmospheric environment to the vacuum chamber 5 can be prevented without creating a gap with the lower surface of the seal case 17.

  In addition, the seal case 17 can be made to follow the output shaft 80, and the portion where the first seal member 30 and the output shaft 16 are intensively pressed can be reduced, and a gap is created between the first seal member 30 and the output shaft 16. I won't let you. That is, the deviation between the input shaft 70 and the output shaft 80 is absorbed by the second sealing material 40, and a gap is not generated between the first sealing material 30 and the output shaft 16. Leakage can be prevented.

  The operations and effects described above can be similarly achieved by the second sealing material 50/60. In this way, leakage from the atmospheric environment to the vacuum chamber 5 can be prevented even for the power transmission device 90 in which the axes of the input shaft 70 and the output shaft 80 are shifted in advance.

The partial cross section block diagram which shows the whole structure of the robot arm containing the power transmission mechanism which concerns on this invention. The perspective view which similarly shows the whole structure of a 2nd sealing material. The perspective view which similarly shows the whole structure of another 2nd sealing material. The perspective view which similarly shows the whole structure of another 2nd sealing material. The partial cross section block diagram which shows the whole structure of a robot arm in case an output shaft has inclination. The partial cross section block diagram which showed the whole structure of the power transmission mechanism which concerns on another Example similarly. The partial cross section block diagram which showed the whole structure of the power transmission device in case there exists a shift | offset | difference in an output shaft.

DESCRIPTION OF SYMBOLS 1 Robot arm 5 Vacuum chamber 6 Base wall 10 Power transmission mechanism 15 Flange 16 Output shaft 17 Seal case 20 Arm 30 First seal material 40 Second seal material 50 Second seal material 60 Second seal material 70 Input shaft 80 Output shaft 90 Power transmission device

Claims (2)

A base wall that separates the vacuum chamber, which is a vacuum environment, from the atmospheric environment;
An output shaft disposed through the base wall;
A seal case for rotatably supporting the output shaft;
A power transmission mechanism comprising:
A first sealing material interposed in close contact between the seal case and the output shaft;
It is interposed between the bottom surface of the seal case and the upper surface of the base wall, has elasticity in the axial direction of the output shaft, and when the output shaft is inclined, the lower surface is formed by elastic deformation. A second layer of laminated rubber that forms a top surface that is inclined with respect to a horizontal plane and that follows the inclined bottom surface of the sealing case, and is formed by laminating a rubber material and a metal material and covering the surface with rubber. Sealing material,
A power transmission mechanism comprising: A base wall that separates the vacuum chamber, which is a vacuum environment, from the atmospheric environment;
An output shaft disposed through the base wall;
A seal case for rotatably supporting the output shaft;
A power transmission mechanism comprising:
A first sealing material interposed in close contact between the seal case and the output shaft;
It is interposed between the bottom surface of the seal case and the upper surface of the base wall, has elasticity in the axial direction of the output shaft, and when the output shaft is inclined, the lower surface is formed by elastic deformation. Forming a top surface having an inclination with respect to a horizontal plane, a second sealing material that is a hollow cylindrical metal expansion and contraction tube that follows the inclined bottom surface of the sealing case;
A power transmission mechanism comprising:

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