JPH1133947A - Double shaft rotary driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the drive control by driving the only first driving motor so that a second rotary output shaft, which is coaxially fitted to a second driving motor, is synchronously rotated with a first rotary output shaft to be driven by the first driving motor. SOLUTION: A first rotary output shaft 3 is coaxially fitted to a motor rotary shaft 1a of a first driving motor 1 through a coupling 7. The first rotary output shaft 3 is formed into a hollow cylindrical shape, of which rear part 3b close to the first driving motor is closed and of which front part 3a far from the first driving motor 1 is opened. A second driving motor 2 is fitted in the hollow cylindrical first rotary output shaft 3 so that a motor rotary shaft 2a is coaxially fitted to the first rotary output shaft 3. A second rotary output shaft 4 is coaxially fitted to the motor rotary shaft 2a of the second driving motor 2 through a coupling 8. With this structure, posture of a robot arm is maintained so as to perform the rotary carrying of semi-conductor substrate without synchronously adjusting the driving motors, and complicated drive control is thereby eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-axis rotary drive device in which rotational output is taken in the same direction and coaxial with each other. 2 suitable for driving source of transfer robot
The present invention relates to a shaft rotation driving device.

[0002]

2. Description of the Related Art Conventionally, a conventional two-wheel drive system is used as a drive source of a transfer robot for transferring a semiconductor substrate between processing stations.
FIG. 6 shows the configuration of the shaft rotation drive device.

[0003] In order to enable coaxial two-axis rotation in the same direction in which the rotational output is taken out, the rotary output shafts of the two motors 21 and 22 include a hollow first rotary output shaft 23 and a hollow first rotary output shaft 23. It is composed of two shafts, a second rotation output shaft 24 coaxially arranged in the rotation output shaft 23. Drive motors 21 and 22 called direct drive motors are provided coaxially around the first rotation output shaft 23 and the second rotation output shaft 24 via a rotation load holding bearing 25. The first rotation output shaft 23 or the second rotation output shaft 24 is driven independently or synchronously by these drive motors 21 and 22.

As shown in FIG. 7, the drive of the first rotary output shaft 23 is not performed by a direct drive motor, but by a timing pulley 28 wound around the first rotary output shaft 23 and a timing belt 29 via a coupling 27. It may be performed by the general-purpose motor 21a.

When the above-described two-axis rotary drive device is employed as a drive source of a transfer robot for transferring a semiconductor substrate, the two-axis rotary drive device is connected to a robot arm 6 as shown in FIG.

The robot arm 6 has two hollow arms 6
It consists of 1, 62 and has three joints. First joint 6A
Is provided at the base of the first arm 61, the second joint 6B is provided at the connection between the first arm 61 and the second arm 62, and the third joint 6C is provided at the tip of the second arm 62. First joint 6
The first arm 61 is rotated about A, the first arm 61 and the second arm 62 are relatively rotated about the second joint 6B, and the substrate receiving plate 67 is rotated about the third joint 6C. Has become.

[0007] As described above, the two-axis rotary driving device includes a direct-rotation motor provided coaxially below the direct-drive motor 21 in a hollow cylindrical first rotary output shaft 23 driven to rotate by the direct-drive motor 21. The first rotation output shaft 23 and the second rotation output shaft 24 are inserted through the second rotation output shaft 24 driven and rotated by the drive motor 22.
Are rotatably supported.

A base end of a first arm 61 is fixed to an upper end of a second rotation output shaft 24 serving as a first joint shaft and is rotatably provided. A connecting shaft 64 serving as a second joint shaft is rotatably provided on the distal end side of the first arm 61, and the connecting shaft 64 protrudes above the first arm 61, and a second arm 62 is provided on the upper end of the connecting shaft 64.
Is fixed.

A fixed pulley 6 is mounted on the upper end of the first rotary output shaft 23.
3, a transmission pulley 64a having an enlarged diameter is provided at the lower end of the connecting shaft 64 inside the first arm 61.
And the transmission pulley 64a are connected by a belt 68.

A floating pulley 65 is fixedly mounted on the second arm 62, the second arm 62 is rotatably fitted to the floating pulley 65, and the connecting shaft 64 is rotatably penetrated through the floating pulley 65. A driven shaft 66 serving as a third joint axis is rotatably provided at the tip end of the rotation of the second arm 62, and a driven pulley 66a having an enlarged diameter is provided at the lower end of the driven shaft 66. The driven pulley 66a and the idle pulley 65 Connect by 69. Then, a substrate receiving plate 67 is fixed to the upper end of the driven shaft 66.

FIG. 9 is a plan view of the robot arm 6 at the standby position when the first arm 61 and the second arm 62 overlap with each other, and shows the semiconductor substrate on a tweezer 67 a attached to a substrate receiving plate 67. This shows a state where W is placed.

The operation of the robot arm 6 when the second drive motor is operated while the first drive motor is stopped and held will be described with reference to FIG. In addition, stopping the motor means to lock the rotation of the rotation output shaft without driving the motor. When the second drive motor is operated to rotate the rotation output shaft 24 counterclockwise, the first
The arm 61 also rotates counterclockwise. With this rotation, the fixed pulley 63 relatively rotates, and the relative rotation of the fixed pulley 63 is transmitted to the transmission pulley 64a via the belt 68, and the transmission pulley 64a moves the second arm 62 clockwise through the connection shaft 64. To rotate.

The rotation of the second arm 62 with respect to the first arm 61 causes relative rotation between the second arm 62 and the idle pulley 65, and this relative rotation is transmitted to the driven pulley 66 a via the belt 69. The driven pulley 66a rotates the substrate receiving plate 67 through the driven shaft 66 in the clockwise direction.

The fixed pulley 63 and the transmission pulley 64a
And the rotation ratio between the idler pulley 65 and the driven pulley 66a is an inverse ratio (2: 1). By this reciprocal ratio,
As shown in the schematic diagram of FIG. 11, when the first arm 61 rotates by an angle α, the second arm 62 rotates by an angle 2α in conjunction therewith. As a result, the substrate receiving plate 67 moves linearly while maintaining the same posture, and the robot arm 6 can perform one-way stable transfer of the semiconductor substrate W.

The robot arm 6 of the transfer robot described above adopts three transfer styles shown in FIGS. 12 to 14 by a combination of driving and stopping and holding the first drive motor 21 and the second drive motor 22.

(1) One-way transfer (FIG. 12) This is the transfer style already described with reference to FIG. 10, in which the first drive motor 21 is stopped and held, and only the second drive motor 22 is driven. The robot arm 6 holds the substrate receiving plate 67 in the same posture, and (a) → (b) →
As shown in (c), the semiconductor substrate W is transferred in one direction by linearly moving.

(2) Rotary conveyance (FIG. 13) When only the driving motor 21 is driven and the second driving motor 22 is stopped and held, the first arm 61 does not move and only the second arm 62 rotates. Thereby, the robot arm 6 operates in the order of (a) → (b) → (c) to carry the semiconductor substrate W by rotating the semiconductor substrate W by 90 °.

(3) Posture Holding and Conveying (FIG. 14) When the two rotation output shafts 23 and 24 are simultaneously driven while synchronizing the driving motors 21 and 22, the first arm 61 and the second arm 62 It rotates while overlapping as in the standby position. Thereby, the robot arm 6
(A) → (b) → (c), the semiconductor substrate W is transported by 90 ° while the arm posture is held.

[0019]

However, when the above-described conventional two-axis rotary driving device is used for the robot arm, the driving motors 21 and 22 are required to carry out the attitude holding and transport of the semiconductor substrate W shown in FIG. The drive control must be complicated because the drive must be performed while synchronizing the data.

Further, the use of a direct drive motor has the disadvantage that the apparatus becomes expensive.

Therefore, an object of the present invention is to solve the problems of the prior art and to solve the problem of two motors arranged coaxially.
By driving the other motors together with one motor by one motor, posture holding conveyance can be performed without synchronization adjustment.
An object of the present invention is to provide a simple and easy-to-control two-axis rotary drive.

[0022]

To achieve the above object, a two-axis rotary driving device according to the present invention is mounted coaxially on a first driving motor and a motor rotating shaft of the first driving motor. (1) A hollow cylindrical first cylinder whose rear part in the axial direction close to the drive motor side is closed and whose front part far from the motor side is open
A second drive motor, a second drive motor, and a second drive motor, the motor output shaft being integrally mounted within the first output output shaft having a hollow cylindrical shape, the rotation output shaft being coaxial with the first output output shaft. A second rotary output shaft which is coaxially attached to a motor rotary shaft of the motor and is coaxially taken out from the open front of the hollow cylindrical first rotary output shaft. .

In the present invention, when the second drive motor is stopped and held and the first drive motor is driven, the first hollow rotary output shaft rotates. Since the second drive motor is integrally mounted in the hollow cylindrical first rotation output shaft, the second drive motor itself rotates with the rotation of the first rotation output shaft. Therefore, the internal second rotation output shaft attached to the motor rotation shaft of the second drive motor also rotates. That is, by driving only the first drive motor, the second rotation output shaft is synchronously rotated with the first rotation output shaft without synchronizing the two drive motors, and the posture conveyance style of FIG. Can be realized.

Further, the second drive motor is driven to drive the first drive motor.
When the driving motor is stopped and held, the external first rotary output shaft does not rotate, and only the internal second rotary output shaft rotates. Therefore, the one-way conveyance in FIG. 12 can be realized by the rotation of only the second rotation output shaft.

According to the present invention, when the first rotation output shaft is rotated, the second rotation output shaft is simultaneously rotated even if the second drive motor is stopped and held. Unless a rotation that cancels the rotation of the shaft is given to the second rotation output shaft, the transport style of FIG. 13 in which only the first rotation output shaft is rotated cannot be realized. However, in the transfer style of the semiconductor substrate by the robot arm 6 described above, the transfer style of FIGS. 12 and 14 is mainly used and the frequency of use is high.
Since the transport style of No. 3 is special, there is no particular problem even if it is excluded.

Since the two-axis simultaneous drive in the same direction is possible as described above, when the two-axis rotary drive device of the present invention is used as a drive source of a semiconductor substrate transfer robot, a posture holding transfer frequently used is performed. It is not necessary to drive the two driving motors while adjusting them synchronously as in the prior art.
Drive control is simplified.

Further, since the second drive motor is integrally mounted in the hollow cylindrical first rotary output shaft so that the two drive motors can be arranged coaxially, it is expensive. Without using a direct drive motor,
A general-purpose motor can be used.

When deceleration is required, the motor rotation shaft of the first drive motor is connected to the first output rotation shaft via a coupling and a speed reducer, and the motor rotation shaft of the second drive motor is connected. May be connected to the second rotation output shaft via a coupling and a speed reducer.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a two-axis rotary drive device.

The first drive motor 1 and the second drive motor 2 are both general-purpose motors. A first rotation output shaft 3 is coaxially attached to a motor rotation shaft 1 a of the first drive motor 1 via a coupling 7. The first rotation output shaft 3 is formed in a hollow shape, the rear portion 3b in the axial direction near the first drive motor side is closed, and the front portion 3 far from the motor 1 side.
a has an open cylindrical shape. The first rotation output shaft 3 is
The front part 3a and the rear part 3 formed to have smaller diameters than the intermediate part.
b of the projection shaft 3e is the rotation load holding bearing 5a, 5b.
It is rotatably supported by support frames 11 and 12 via b.

The second drive motor 2 is integrally mounted in the hollow cylindrical first rotation output shaft 3 such that the motor rotation shaft 2 a is coaxial with the first rotation output shaft 3. The second rotation output shaft 4 is coaxially attached to the motor rotation shaft 2 a of the second drive motor 2 via a coupling 8. This second rotation output shaft 4 is a hollow cylindrical first shaft.
The rotation output shaft 3 is provided coaxially with the first rotation output shaft 3 so as to protrude in the axial direction from the open front portion 3a. The second rotation output shaft 4 is rotatably supported on the inner wall of the open front part 3a via a bearing 5c.

In the above configuration, when the second drive motor 2 is stopped and held and the first drive motor 1 is driven, the hollow cylindrical first rotation output shaft 3 rotates. Since the second drive motor 2 is integrally mounted in the hollow cylindrical first rotation output shaft 3, the second drive motor 2 itself rotates with the rotation of the first rotation output shaft 3. Therefore, the internal second rotation output shaft 4 attached to the motor rotation shaft 2a of the second drive motor 2 also rotates. By driving only the first drive motor 1 in this manner, the second rotation output shaft 4 can be rotated synchronously with the first rotation output shaft 3.

When the second drive motor 2 is driven and the first drive motor 1 is stopped and held, the external first rotation output shaft 3 does not rotate, but the internal second rotation output shaft 4 does not rotate. Only rotate. Therefore, rotation of only the second rotation output shaft 4 can be secured.

Next, the operation of the robot arm 6 when the above-described two-axis rotary drive device is employed as a drive source of a transfer robot will be described with reference to FIGS. Robot arm 6
Is the same as that shown in FIG. The manner in which the first and second rotation output shafts 3 and 4 of the drive motors 1 and 2 are connected to the robot arm 6 is also the same as in FIG. However, it is assumed that the first arm 61 is connected to the internal second rotation output shaft 4.

(1) The first drive motor 1 is stopped and held, and only the second drive motor 2 is driven (FIG. 2). The second drive motor 2 is operated to rotate its rotation output shaft 24 counterclockwise. Then, the first arm 61 also rotates counterclockwise, and with this rotation, the second arm 62 rotates clockwise. When the second arm 62 rotates with respect to the first arm 61, the substrate receiving plate 67 rotates counterclockwise. As a result, the robot arm 6 (a) → (b) →
The semiconductor substrate W is moved in one direction in a straight line by operating as shown in FIG.

(2) The second drive motor 2 is stopped and held, and only the first drive motor 1 is driven (FIG. 3). When the first rotation output shaft 3 is rotated by the first drive motor 1, it is held inside. The second driving motor 2 is also rotated together, so that the pulley 6
No relative rotation of 3 occurs. Therefore, the belt 6
No rotation occurs in the second pulley 64a connected via the second pulley 8. Therefore, the robot arm 6 is
1. In the state in which the second arm 62 is kept in an overlaid posture, the semiconductor substrate W is rotated and transported by operating from (a) to (b) → (c).

As described above, when only the first driving motor 1 is stopped and held, and only the second driving motor 2 is driven, one-way conveyance can be performed as in the conventional case. Also, simply the second
The drive motor 2 is stopped and held, and only the first drive motor 1 is driven, so that the rotary transfer of the semiconductor substrate W can be performed with the robot arm 6 in a posture-held state without synchronizing the two drive motors. And complicated drive control as in the related art is not required.

In the above-described embodiment, the first rotation output shaft 3 and the second rotation output shaft 4 are directly driven by the drive motors 1 and 2, however, as shown in FIG.
Transmissions 13 and 14 are provided between the first drive motor 1 and the first rotation output shaft 3 and between the second drive motor 2 and the second rotation output shaft 4, respectively. Is also possible.

To shorten the axial configuration, as shown in FIG. 5, the first driving motor 1 is
The first drive motor 1 is formed by further extending the projection shaft 3e of the rear portion 3b of the first rotation output shaft 3 and juxtaposing the extension shaft 3c.
And a timing pulley 17 is provided on the motor rotation shaft 1 a via a coupling 15, while an extension shaft 3 c of the first rotation output shaft 3 is extended via the transmission 13 and the coupling 7. A timing pulley 19 is provided in the section, and the timing pulleys 17 and 19 are connected by a timing belt 31.

On the second drive motor 2 side,
The first rotary output shaft 3 is mounted eccentrically from the center of the cylinder, and the drive motor 2 is arranged side by side with the second rotary output shaft 4 in the hollow cylindrical portion of the first rotary output shaft 3.
And a timing pulley 18 is provided on the motor rotation shaft 2 a via a coupling 16, while the second rotation output shaft 4 is extended via the transmission 14 and the coupling 8, and a timing pulley is A timing belt 20 is provided between the timing pulleys 18 and 20.

As described above, the timing pulleys 17 and 18
And the timing belts 31, 32, the driving motor 1,
By arranging the position 2 in parallel with the drive shaft, the axial length of the device can be reduced.

In the above-described embodiment, a general-purpose motor is used, but a direct drive motor may be used. Further, the present invention can be applied to a rotary drive device having three or more axes.

[0043]

According to the present invention, by driving only the first drive motor, the second rotary output shaft coaxially mounted on the second drive motor is driven by the first drive motor. Since the motor can be rotated synchronously with the first rotation output shaft, complicated control for driving the two driving motors while adjusting them synchronously is not required, and drive control is simplified.

By mounting the second drive motor in the hollow cylindrical first rotary output shaft, the two drive motors and the components are mounted coaxially to enable simultaneous two-axis drive in the same direction. Thus, a general-purpose motor can be used without using an expensive direct drive motor, and the apparatus can be configured at low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a two-axis rotary drive device according to an embodiment.

FIG. 2 is an operation explanatory view of the robot arm of the embodiment.

FIG. 3 is an operation explanatory view of the robot arm of the embodiment.

FIG. 4 is a configuration diagram of another embodiment of a two-axis rotary driving device.

FIG. 5 is a configuration diagram of still another embodiment of a two-axis rotary drive device.

FIG. 6 is a configuration diagram of a drive unit of a conventional two-axis rotary drive device.

FIG. 7 is a configuration diagram of another driving unit of a conventional two-axis rotary driving device.

FIG. 8 is a longitudinal sectional view of a conventional substrate transfer robot arm.

FIG. 9 is a plan view of a conventional substrate transfer robot arm.

FIG. 10 is an operation explanatory view of the robot arm of FIG. 8;

FIG. 11 is an explanatory diagram of an opening angle of movement of the robot arm of FIG. 8;

FIG. 12 is an operation explanatory view of a conventional substrate transfer robot arm to which a two-axis rotary drive device is applied when the motor 1 is stopped and held and the motor 2 is driven.

FIG. 13 is a diagram illustrating the operation of a conventional substrate transfer robot arm to which a two-axis rotation drive device is applied when the conventional motor 1 is driven and the motor 2 is stopped and held.

FIG. 14 is a diagram illustrating the operation of a conventional robot arm for transferring a substrate to which a two-axis rotation driving device is applied when two axes are simultaneously driven.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st drive motor 1a Motor rotation axis of 1st drive motor 2 2nd drive motor 2a Motor rotation axis of 2nd drive motor 3 1st rotation output shaft 3a Front part of 1st rotation output shaft 3b 1st Rear part of rotation output shaft 3e Projection shaft at rear part of first rotation output shaft 4 Second rotation output shaft

Claims (1)

[Claims] A first drive motor and a first drive motor, which are coaxially mounted on a motor rotation shaft of the first drive motor, have an axial rear portion close to the first drive motor side, and a front portion far from the motor side. An open hollow cylindrical first rotary output shaft; and a second drive unit integrally mounted in the hollow cylindrical first rotary output shaft such that the motor rotary shaft is coaxial with the first rotary output shaft. And a second rotation output coaxially attached to the motor rotation shaft of the second drive motor and taken out coaxially with the first rotation output shaft from the open front of the hollow cylindrical first rotation output shaft. And a shaft.