JP2008064626A - Rotary positioning table device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly-accurate and easily-manufacturable rotary positioning table device. <P>SOLUTION: This device is equipped with a rotary table 14, an air bearing 16 and magnetic suction parts 18, 20, 22 for supporting the rotary table 14 rotatably, a roller follower 32 for applying a torque to the rotary table 14 end, and a linear actuator 30 for rotating and driving the roller follower 32. A partial domain of the rotary table 14 is floated by the air bearing 16, and the other domain of the rotary table 14 is sucked in the vertical direction by the magnetic suction parts 18, 20, 22, and balance is taken between an unbalance component caused by supporting the rotary table 14 in a cantilevered state and the load in the gravity direction of a loaded object. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary positioning table device, and in particular, is used in various precision machines for manufacturing semiconductors and liquid crystals. The positioning object such as a work or an optical head mounted on a table is minute. The present invention relates to an improvement in the structure of a rotary positioning table device that can be positioned at an angle.

2. Description of the Related Art Conventionally, as a table positioning device, there is one in which a bearing is disposed at the center of a rotary table and an arm portion protruding from an outer peripheral portion of the rotary table is driven to perform rotary positioning (see Patent Document 1).
Japanese Patent Laid-Open No. 2002-341076

  However, in the conventional rotary positioning table, if it is necessary to enlarge the hollow hole of the table or increase the size of the table, the rotary bearing itself must be enlarged. When the rotary bearing is enlarged, there is a problem that it is extremely difficult to maintain the rotational accuracy due to the limit of the processing accuracy, the manufacturing cost becomes high, and the production delivery time is also required.

  Therefore, an object of the present invention is to provide a rotary positioning table device that is easy to manufacture and highly accurate.

  In order to achieve the above object, the present invention provides an unbalanced load by mounting a rotating bearing at the end of the rotating table without mounting the rotating bearing at the center of the rotating table. The load in the gravity direction of the object is compensated by the magnetic attraction force of the magnetic attraction member provided at the other end of the rotary table.

 Specifically, the present invention includes a rotary table that is rotatably arranged, a plurality of support members that are distributed with respect to the rotary table and rotatably support the rotary table, and the rotary table. A drive unit that rotationally drives, a part of the plurality of support members levitates a part of the rotary table to restrain the rotation direction of the rotary table, and the other support members include The rotary positioning table device is constructed by sucking other areas of the rotary table in the vertical direction.

 According to the present invention, without providing a rotary bearing in the center of the rotary table, a partial area of the rotary table is levitated by a part of the support member, an unbalanced load due to the cantilever of the rotary table, and a load The load in the gravitational direction is compensated by the magnetic attractive force of the other support member provided in the other area of the rotary table, so that a small and accurate rotary positioning table device can be realized and a large bearing is used. In addition, since a large-sized rotary table can be realized, it is possible not only to freely design the intended size according to the application, but also to reduce the cost and shorten the production delivery time. In addition, since gravity compensation of the load on the load can be performed in a non-contact manner, there are absolutely no factors that deteriorate the rotation accuracy, and it is possible to easily realize development to a large size while maintaining high accuracy.

 In constructing the rotary positioning table device, some supporting members may be composed of static pressure air bearings, or the drive unit may be reciprocated along a straight line, and the reciprocating motion of the linear actuator may be rotated. Or a roller follower that applies rotational force to the end of the rotary table and an elastic body that connects the end of the rotary table and the linear actuator and pulls the end of the rotary table toward the linear actuator. Can do.

  According to the present invention, a small and accurate rotary positioning table device can be realized, and a large-sized rotary table can be realized without using a large bearing, so that it can be freely designed to an intended size according to the application. In addition, cost reduction and production delivery time can be shortened. In addition, since gravity compensation of the load on the load can be performed in a non-contact manner, there are absolutely no factors that deteriorate the rotation accuracy, and it is possible to easily realize development to a large size while maintaining high accuracy.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a rotary positioning table device showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of the rotary positioning table device, and FIG. 3 is a side view of the rotary positioning table device. is there. 1 to 3, the rotary positioning table device 10 includes a base (θ-axis base) 12 and a rotary table 14, and a hydrostatic air bearing 16 and a base 12 formed in a substantially rectangular shape. The magnetic attraction portions 18, 20, and 22 are divided and fixed at substantially four corners, and the rotary table 14 is fixed to the upper surfaces of the static pressure air bearing 16 and the magnetic attraction portions 18, 20, and 22.

The hydrostatic air bearing 16 is configured as an air bearing, the fixed body 16a is fixed to the base 12, the upper surface of the rotating body 16b is fixed to the bottom surface of the rotating table 14, and the hollow holes 14a and the corners 14b of the rotating table 14 are fixed. The area between the two is levitated without contact.
The magnetic attraction units 18, 20, and 22 are configured to include an L-shaped attraction material 24, an L-shaped support member 26, and a magnet 28, and the attraction material 24 has one end on the rotary table 14. It is fixed to the bottom surface, and the other end is arranged substantially parallel to the rotary table 14 and opposed to the magnet 28. One end of the support member 26 is fixed to the base 12, and the other end is disposed substantially parallel to the turntable 14. A magnet 28 is fixed to the side of the support member 26 facing the suction member 24. The magnet 28 is disposed opposite to the attracting material 24 while maintaining a certain gap, and the attracting material 24 is always attracted upward (on the turntable 14 side) by the magnetic attraction force of the magnet 28.

That is, the magnetic attraction unit 18 attracts the region between the hollow hole 14a and the corner 14c of the rotary table 14 in the vertical direction with the magnetic attraction force, and the magnetic attraction unit 20 has the hollow hole 14a in the rotary table 14. The magnetic attraction portion 22 is vertically attracted by the magnetic attraction force, and the magnetic attraction portion 22 is perpendicular to the area between the hollow hole 14a and the corner portion 14e of the rotary table 14 by the magnetic attraction force. It comes to be sucked into.
Thereby, it is possible to balance the unbalance component due to the cantilever of the rotary table 14 and the load in the gravity direction of the load. At this time, it is desirable to appropriately set the attraction force of each magnetic attraction unit 18 according to the weight of the turntable 14 and the load on the load. For example, the magnetic flux density and size of the magnet 28 and the gap adjustment between the magnet 28 and the attracting member 24 are not particularly limited, and the location and number of magnetic attraction by the magnet 28 may be set as appropriate.

On the other hand, a uniaxial actuator (linear actuator) 30 capable of linear positioning is installed in the vicinity of the end 14f of the rotary table 14 that is a movable body. The uniaxial actuator 30 is configured as one element of a drive unit, and a roller follower 32 is connected to the tip of the uniaxial actuator 30 in this embodiment. The roller follower 32 is pressed against the end portion 14 f of the rotary table 14 by the elastic force of a tension coil spring (elastic body) 34 that connects the uniaxial actuator 30 and the end portion 14 f of the rotary table 14. In this state, when the uniaxial actuator 30 is driven forward and backward with respect to the rotary table 14, the reciprocating linear motion accompanying the forward and backward movement of the uniaxial actuator 30 is converted into rotational motion by the roller follower 32, and the rotational force is converted into the rotary table. 14, the rotary table 14 is positioned.
Since the uniaxial actuator 30 is arranged at a position different from the static pressure air bearing 16, the distance between the rotation center of the static pressure air bearing 16 and the drive point of the uniaxial actuator 30 (end 14f of the rotary table 14) is increased. By setting, the rotational positioning resolution can be increased in proportion to the distance from the rotation center of the hydrostatic air bearing 16 to the drive point of the uniaxial actuator 30.

 According to the present embodiment, it is possible to realize a small and accurate rotary positioning table device 10. Specifically, since a large-sized rotary table can be realized without using a large bearing, it can be freely designed to an intended size according to the application, and cost reduction and production delivery time can be shortened.

In addition, since the gravity compensation of the load on the load can be made non-contact, there is no limit to the factors that deteriorate the rotation accuracy, and it is possible to easily realize development to a large size with high accuracy.
Furthermore, if high accuracy is desired, the use of a hydrostatic air bearing as a rotary bearing enables gravity compensation for unbalanced loads, so a small air bearing can be used, and low-cost, high-accuracy rotational positioning is possible. The table device 10 can be realized.

It is a top view of the rotation positioning table apparatus which shows one Example of this invention. It is sectional drawing which follows the AA line of a rotation positioning table apparatus. It is a side view of a rotary positioning table device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rotation positioning table apparatus 12 Base 14 Rotation table 16 Static pressure air bearing 18, 20, 22 Magnetic attraction part 24 Attraction material 28 Magnet 30 Uniaxial actuator 32 Roller follower 34 Pulling coil spring

Claims (3)

A rotary table that is rotatably arranged, a plurality of support members that are distributed with respect to the rotary table and rotatably support the rotary table, and a drive unit that rotationally drives the rotary table, Among the plurality of support members, a part of the support members levitates a part of the rotary table to restrain the rotation direction of the rotary table, and the other support members set other areas of the rotary table. A rotary positioning table device that sucks in the vertical direction. The rotary positioning table device according to claim 1, wherein the part of the support members is configured by a static pressure air bearing. The drive unit includes a linear actuator that reciprocates along a straight line, a roller follower that converts the reciprocating motion of the linear actuator into a rotary motion and applies a rotational force to an end of the rotary table, and an end of the rotary table The rotary positioning table device according to claim 1, further comprising: an elastic body that connects the linear actuator to the linear actuator and pulls an end of the rotary table toward the linear actuator.

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