JP2696262B2 - Rotation restraint device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device in an exposure printing apparatus used in various processing machines, measuring machines, or semiconductor lithography processes.

[Prior Art] FIG. 3 shows a longitudinal sectional view of a conventional example. FIG. 4 is a view on arrow A of FIG. 1 is a table, 2 is a base plate (ball push outer cylinder), 3 is a ball push inner cylinder, 4
Is a steel ball. The table 1 is guided by sliding vertically with respect to the base plate 2. The guide member 14 is fixed to the cable 1. Reference numeral 15 denotes a roller follower, which is fixed to a bearing housing 18 by a shaft 17 via a spacer 16. The bearing housing 18 is fixed to the base plate 2. A first spring hook 19 is fixed to the shaft 17. Reference numeral 20 denotes a second spring hook, which is fixed to the guide member 14. 21 is a preload spring.

In the above configuration, the guide member 14 is abutted against the roller follower 15 with an appropriate preload by the preload spring 21.
As a result, the degree of freedom of the table 1 in the rotation direction with respect to the base plate 2 is restricted, and the table 1 is driven vertically by a driving device (not shown).

[Problems to be Solved by the Invention] However, in the above-described conventional example, the rolling friction of the contact portion between the guide member 14 and the roller follower 15 for restricting the degree of freedom in the rotational direction of the table 1 with respect to the base plate 2 and the rolling of the roller follower 15 itself. Due to the friction, when the table 1 was driven, the table was tilted as shown by a two-dot chain line in FIG. 3, and high-precision feeding was not possible.

The component accuracy (flatness, squareness) of the guide member 14 and the roundness and rotation accuracy of the roller follower 15 are directly determined by the table 1.
There is a drawback that it is expressed as a positional deviation amount in the rotation direction of.

The present invention has been made in view of the above-described disadvantages of the related art, and achieves a high-precision feeding operation by improving a guide mechanism between members that slide through each other or move via a rolling bearing, and achieves a guide member. It is an object of the present invention to provide a rotation restraining device in which the component accuracy does not directly affect the feeding operation accuracy.

[Means and Actions for Solving the Problems] In order to achieve the above object, according to the present invention, the means for restraining the degree of freedom in the rotation direction of the table 1 with respect to the base plate 2 is constituted by a static pressure bearing, and the rolling friction and the like are reduced. This eliminates resistance, prevents inclination when the table 1 is driven, and enables high-precision feeding.

Embodiment FIG. 1 is a longitudinal sectional view of an embodiment of the present invention. FIG. 2 shows an AA cross section of FIG. 1 is a table, 2 is a base plate (ball push outer cylinder), 3 is a ball push inner cylinder, and 4 is a steel ball. The table 1 is mounted movably in the normal direction with respect to the base plate 2. The guide member 5 is fixed to the table 1. Reference numerals 6 and 7 denote bearing housings, which are fixed to the base plate 2. For example, porous bodies 8, 8 'made of a carbon-based porous material are fixed to bearing housings 6, 7 by means such as adhesion. 9, 9 '
Are hollow air supply holes provided in the bearing housings 6 and 7. Reference numerals 10 and 10 'denote gap adjusting members. Micro gaps 13, 13 'are formed between the guide member 5 and the porous bodies 8, 8'. Supply holes 9, 9 'provided in bearing housings 6, 7
The air supply hoses 15 and 15 'respectively communicate with the air supply hoses. Air supply hose 1
Valves 16 and 16 'are provided in the middle of 5, 15'.

In the above configuration, when the pressurized gas is supplied to the air supply hoses 15 and 15 'and the valves 16 and 16' are opened, the pressurized gas is supplied to the porous bodies 8 and 8 'through the air supply holes 9 and 9'. . As a result, a fluid lubricating film is formed in the minute gaps 13 and 13 ', and both sides of the guide member 5 are supported in a non-contact manner in a direction in which the porous bodies 8 and 8' face each other. Thereby, the movement of the table 1 in the rotation direction is restricted. In this state, the table 1 is
, The one valve 16 is closed at an arbitrary position, and the supply of the pressurized gas to the air supply hole 9 on the side where the valve 16 communicates is stopped. As a result, the guide 5 is pressed against the porous body 8 on which the air supply has been stopped by the pressure of the fluid lubricating film formed in the minute gap 13 'on the opposite side, and the table 1 is fixedly held. That is, by supplying a pressurized gas to both the porous bodies 8 and 8 ', the movement of the table 1 in the rotation direction can be restrained in a non-contact manner without generating a resistance such as friction on the guide 5 and so on. , High-precision table feed depending on the accuracy of the ball push composed of the ball push inner cylinder 3 and the steel ball 4 becomes possible. In addition, the table 1 holds the porous bodies 8, 8 'when stopped.
The guide 5 is stopped by stopping the supply of one pressurized gas.
High rigidity can be maintained in the moving direction by the frictional force generated between the and the porous body.

FIG. 5 and FIG. 6 show a second embodiment of the present invention.
FIG. 6 shows an AA cross section of FIG. The same members as those in the first embodiment are given the same numbers. In this embodiment, the guide member 5 is made of a magnetic material and fixed to the base plate 2. Numeral 14 denotes a magnet, which is fixed to the bearing housing 6 by means such as adhesion.

When the pressurized gas is supplied to the air supply hose 15 and the valve 16 is opened, the pressurized gas is supplied to the porous body 8 through the air supply hole 9 and a fluid lubricating film is formed in the minute gap 13. When the pressure of the fluid lubricating film applied to the guide member 5 and the attraction force of the magnet 14 acting on the guide member are balanced, the guide member 5 is supported in a non-contact manner in a direction facing the porous body 8, and the rotation of the table 1 is performed. Constrain movement in direction.

In this state, when the table 1 is moved in the normal direction with respect to the base plate 2 and the valve 16 is closed at an arbitrary position to stop the pressurized gas supplied to the air supply hole 9, the guide 5
The attractive force of the magnet 14 attracts and contacts the porous body 8 to generate a frictional force, thereby fixing and holding the table 1.

That is, when the table 1 is moved, by supplying a pressurized gas to the porous body 8, the rotation in the rotation direction of the table can be restrained in a non-contact manner without generating resistance such as friction on the guide 5. , High-precision table feed depending on the accuracy of the ball push composed of the ball push inner cylinder 3 and the steel ball 4 becomes possible. In addition, when the supply of the pressurized gas to the porous body 8 is stopped when the table 1 is stopped, the table 1 can be held with high rigidity in the moving direction by the frictional force generated between the guide 5 and the porous body.

Further, the rotation restraining mechanism including the guide member 5, the bearing housing 6, the porous body 8, and the magnet 14 can be reduced in thickness, so that the weight can be reduced.

Although the hydrostatic bearing according to each of the first and second embodiments uses a porous restrictor made of the porous body 8, other restricting methods such as a magnetic restrictor, an orifice restrictor, and a surface restrictor may be used. .

 Further, a plurality of rotation restraining mechanisms may be provided.

Further, the base plate 2 is not limited to a fixed member, and may be a member constituting a table for positioning in, for example, a rotation direction, an inclination direction, or the like.

[Effect of the Invention] As described above, the base plate 2 of the table 1
By using a hydrostatic bearing to restrict the degree of freedom in the rotational direction with respect to the above, the conventional resistance such as rolling friction is eliminated, the inclination when the table 1 is driven is stopped, and high-precision feeding can be performed.

Further, a table locking means is configured by controlling the supply of pressurized gas to the static pressure bearing, and after the table 1 is positioned, the static pressure bearing is locked so that a change in posture when any external force is applied to the apparatus is minimized. be able to.

Further, it is possible to prevent the precision (partiality, squareness) of the guide member 14, the roundness of the roller follower 15, and the rotational accuracy, which are disadvantages of the related art, from being directly expressed as a positional deviation amount in the rotation direction of the table 1.

[Brief description of the drawings]

1 is a longitudinal sectional view of one embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is a longitudinal sectional view of a conventional example, and FIG. FIG. 5 is a longitudinal sectional view of another embodiment of the present invention, and FIG. 6 is a sectional view taken along line AA of FIG. 1: Table, 2: Base plate, 5: Guide member, 6, 7:
Bearing housing, 8: porous body, 9, 9 ': air supply hole, 14:
magnet.

Claims (3)

(57) [Claims] A rotating member and a fixed member that rotate relative to each other, the rotating member being mounted on the fixed member so as to be movable in a rotation axis direction, and fixing the rotating member to one of the rotating member and the fixed member. A guide member for guiding the member in the rotation axis direction is provided, and the other of the rotation member and the fixed member includes a hydrostatic bearing that engages with a side surface of the guide member to restrain rotation of the rotation member. A lock mechanism for providing rotation control means, and the rotation control means pressing the rotation control means against the side surface of the guide member to lock the rotary member to the fixed member by controlling the supply of pressurized gas to the hydrostatic bearing; A rotation restraint device comprising: 2. The rotation restricting device according to claim 1, wherein said rotation restricting means has hydrostatic bearings on both sides of said guide member in the circumferential direction of rotation. 3. The rotation restricting device according to claim 1, wherein said guide member is made of a magnetic material, and said rotation restricting means includes a magnet provided on a side surface of said guide member.