JPH0688187B2 - Rotary drive - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotary drive device that performs rotary drive. This apparatus is suitable for use in a minute positioning apparatus such as a stage for semiconductor manufacturing equipment.

[Prior Art] As a conventional rotary fine movement stage, as shown in FIG. 5, two semi-disc-shaped members 13 and 13 connected by a hinge 12 of a rotation center are clamped to a base. Piezoelectric element 1 for driving which relatively minutely rotates one of the clampers 14 and 14 and one of the semicircular disk-shaped members 13 and 13.
5, 15 and clampers 14 and 14 in the sequence shown in FIG.
There was an example in which a rotational movement was obtained by moving the driving piezoelectric elements 15, 15. Here, the hatched portion in FIG. 6 shows the member 13 fixed by the clamper 14.

[Problems to be Solved by the Invention] However, in the above-described conventional example, the central portion cannot be used for other purposes because of the presence of the hinge of the rotation center, and the two semi-disc shaped cuts are exceeded. Since it can not be rotated by rotating it, it has a maximum movable range of 180 °, 1
It has a drawback that it cannot rotate more than 80 °, for example 360 °.

The present invention solves the above-mentioned problems, enables a hollow structure, and enables rotation of more than 180 °, and when mounted in a device, it is compact and has few restrictions on movement, and highly accurate positioning is possible. The object is to provide a possible rotary drive.

[Means and Actions for Solving Problems] In order to achieve this object, a rotary drive device of the present invention includes a base and a first bearing that guides a rotary motion in which a rotary shaft is fixed with respect to the base. A second ring shape, which is concentric with the first ring-shaped member, supported by a supported first ring-shaped member and a second bearing that guides rotational movement with respect to the first ring-shaped member. A member, first clamp means fixed to the base and capable of fixing / releasing the first ring-shaped member with respect to the base, and the second ring-shaped member fixed to the base. Second clamp means that can be fixed / released with respect to the base,
It is characterized by having a driving means for relatively minutely displacing the second ring-shaped member in the circumferential direction with respect to the first ring-shaped member. Here, the ring-shaped member also includes a member having a partial ring shape, that is, an arc-shaped member, such as the outer peripheral ring 6 in FIG.

In this configuration, the rotation drive is performed by operating the drive means and the clamp means in a predetermined sequence and repeating the minute rotation, but the rotation shaft and the first and second clamp means are all fixed to the base. Therefore, accurate rotation without eccentricity is performed. Further, by making the first and second ring-shaped members have a closed and complete ring shape, the clamp means sequentially clamps the entire circumferences of the first and second ring-shaped members during rotational driving. Therefore, the rotatable angle is infinite. Also, concentrate all drive mechanisms near the outer periphery of the device,
It is also possible to make the central part of the device a hollow structure.

In this structure, the rotational drive is the above-mentioned drive means and 2
This is performed by operating one clamper in a predetermined sequence and repeating minute rotations.

According to this configuration, it is possible to concentrate all the drive mechanisms near the outer periphery of the device to make the central part of the device have a hollow structure. Furthermore, the first and second members are formed in an annular shape. It is also possible to provide a guide between the second member and the entire circumference so as to enable rotation of more than 180 ° or rotation of the entire circumference.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a rotary stage according to an embodiment of the present invention.
In the figure, 1 is a base, 2 is an inner cylinder fixed to the base, 3 is a bearing for guiding the rotation of the stage, 4 is a driven stage, 5 is elastic deformation guide, 6 is an outer ring, 7,
Reference numeral 8 is a clamper, 9 and 10 are clamper driving piezoelectric elements, and 11 is a rotation driving piezoelectric element.

In the above structure, the driven stage 4 can be fixed and released from the base 1 by the clamper 7, and the outer peripheral ring 6 can be fixed and opened from the base 1 by the clamper 8.

FIG. 2 is a diagram showing a sequence of applied voltages to the piezoelectric elements (electrostrictive elements) 9 to 11 for driving the apparatus shown in FIG. In the figure, A, B and C are piezoelectric elements 9 and 1, respectively.
The waveforms of the applied voltage for 1 and 10 are shown. FIG. 3 is a diagram showing the operation of the device of FIG. 1 when the voltage is changed in the sequence shown in FIG. In the figure, the filled portions show the clampers 7 and 8 and the piezoelectric element 11 which are in operation with a voltage applied. That is, the applied voltage is changed in the sequence shown in FIG. 2 for the piezoelectric elements 9 and 10 that drive the clampers 7 and 8 and the piezoelectric element 11 that drives the outer peripheral ring 6 in the circumferential direction relative to the driven stage 4. By driving in this manner, the rotational movement can be performed by repeating the micro steps as shown in FIG.

In this embodiment, 1) a hollow structure is possible.

2) It can rotate 360 degrees.

3) It can be used in vacuum.

4) Driven stage 4, elastic deformation guide 5, outer peripheral ring 6
By making a single body, it becomes easy to adjust the clamp gap between the clampers 7 and 8 during assembly.

And so on.

[Other Embodiments] FIG. 4 shows a rotary stage according to another embodiment of the present invention. In the figure, 1 is a base, 2 is a shaft fixed to the base, 3 is a bearing, 4 is a driven stage, and 5 is a driven stage.
Is an elastic deformation guide, 6 is an outer ring, 7 and 8 are clampers, and 9 and 1
Reference numeral 0 is a clamper driving piezoelectric element, and 11 is a rotation driving piezoelectric element.

In this structure, the driven stage 4 can be fixed and released from the base 1 by the clamper 7, and the outer peripheral ring 6 can be fixed and released from the base 1 by the clamper 8. In this state, the piezoelectric elements 9 and 10 that drive the clampers 7 and 8 and the piezoelectric element 11 that drives the outer peripheral ring 6 in the circumferential direction relative to the driven stage 4 are applied voltage sequences similar to those in FIG. Driven by, the rotary steps are performed by repeating the same minute steps as in FIG.

This embodiment is suitable for applications in which 360 ° rotation is unnecessary, and 1) a hollow structure is possible.

2) It can be used in vacuum.

3) The area of the driven stage 4 can be made large.

4) Driven stage 4, elastic deformation guide 5, outer peripheral ring 6
By making a single body, adjustment during assembly becomes easy.

And so on.

[Modification of Embodiment] In the above description, the elastic deformation guide 5 is used as a guide for the outer peripheral ring 6, but instead of this, rolling,
You may use bearings such as sliding and static pressure.

EFFECTS OF THE INVENTION As described above, according to the present invention, since accurate rotation without eccentricity can be obtained, the device of the present invention can be applied to highly accurate positioning. Further, by making the first and second ring-shaped members closed and completely ring-shaped, the rotatable angle can be infinite. It is also possible to concentrate all the drive mechanisms in the vicinity of the outer periphery of the device so that the central part of the device has a hollow structure.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is an explanatory diagram of a piezoelectric element driving sequence in the embodiment of the present invention, and FIG. 3 is a driving method in the embodiment of the present invention. 4 is a perspective view of another embodiment of the present invention, FIG. 5 is an explanatory view of a conventional example, and FIG. 6 is a drive explanatory view of the conventional example. 1: Base, 2: Fixed cylinder, 3: Bearing, 4: Driven stage, 5: Elastic deformation guide, 6: Outer ring, 7, 8: Clamper, 9,
10,11: Piezoelectric element.

Claims (4)

[Claims] 1. A base, a first ring-shaped member supported by a first bearing which has a rotation shaft fixed to the base and which guides a rotational movement, and a rotation with respect to the first ring-shaped member. A second ring-shaped member that is concentric with the first ring-shaped member and is supported by a second bearing that guides movement; and fixed to the base, and the first ring-shaped member is provided on the base. A first clamp means that can be fixed / released, a second clamp means that is fixed to the base, and that can fix / release the second ring-shaped member with respect to the base, and a first ring. And a driving unit configured to relatively minutely displace the second ring-shaped member in the circumferential direction with respect to the plate-shaped member. 2. The rotary drive device according to claim 1, wherein the first bearing is a rolling, sliding or static pressure bearing. 3. The rotary drive device according to claim 1, wherein the second bearing is a guide utilizing elastic deformation. 4. The rotary drive device according to claim 3, wherein the first ring-shaped member, the second ring-shaped member, and the elastic guide, which is the second bearing, have an integral structure.