JPS62236638A - Positioning table - Google Patents

Abstract

PURPOSE:To permit the positioning with high precision by pressing a turntable onto a fixed table by an elastic body through spheres and holding the revolution shaft free from gap onto the fixed table by the spheres pressed by the V-type bearing and the elastic body. CONSTITUTION:A turntable 2 is pressed by a fixed table 1 by the aid of a compression spring 7 through at least three arranged spheres 6, and a rotary shaft 8 is held at three points by a V-type bearing 5 whose revolution shaft 8 is fixed onto the fixed table 1 and the sphere 3 pressed by an elastic body 4 free from clearance. Therefore, even if the turntable 2 is applied with a moment load in the thrust direction, the turntable 2 can endure, and the positioning with high precision by the turntable 2 is permitted. Further, even if abrasion is generated, said abrasion is absorbed, and durability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a positioning table that allows highly accurate positioning of a machine.

2. Description of the Related Art A conventional positioning table of this type has a structure as shown in FIG. 3, for example.

That is, the bearing 1 installed in the fixed table e
1 holds the rotary shaft 12 and the rotary table 10 for positioning.

Problems to be Solved by the Invention However, with such a structure, in addition to the fit between the bearing 11 and the rotating shaft 12 and the fit between the bearing 11 and the fixed table 9, there are problems due to play in the bearing 11 itself. 1. There is a problem in that clearances occur in the radial and thrust directions, making it impossible to perform highly accurate positioning.

In addition, if only the bearing 11 is supported, the rotary table 1
There was also the problem that when a moment load was applied to o, it was weak against the moment.

Therefore, the present invention enables highly accurate positioning by eliminating the clearance in the radial and thrust directions, and also allows moment loads to be received.

Means for Solving the Problems The technical means of the present invention for solving the above problems consists of a fixed table, a rotary table integrated with a rotating shaft, a ■-shaped bearing attached to the fixed table, and a rotary table integrated with a rotating shaft. An elastic body and a first ball that press the rotating shaft against the bearing, at least three balls g2 arranged in the gap between the fixed table and the rotating table, and the rotating table fixed to the rotating table via the second balls. It has an elastic body that presses and holds it.

Effects According to the present invention, in the radial direction, due to the above configuration,
The first rotary shaft is pressed by a V-shaped bearing and an elastic body.
The ball is held at three points, eliminating clearance. On the other hand, in the thrust direction, the rotary table
Since the ball is pressed against the fixed table at three or more points by the elastic body, there is no clearance.

As a result, the machine can be positioned with high precision without creating clearances in the radial and thrust directions as in the conventional case.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2. FIG. 1 is a simple front sectional view of the positioning table of this embodiment, and FIG. 2 is a sectional view taken along the line AA in FIG. 1.

In FIGS. 1 and 2, reference numeral 2 denotes a rotary table, which is rotated by a drive source and used to position the machine. This rotary table 2 is held with respect to the fixed table 1 in the following manner. In the radial direction, a rotating shaft 8 integrated with the rotating table 2 is held at three points: a V-shaped bearing 6 attached to the fixed table 1 and a steel ball 3.

Since the steel ball 3 presses the rotary shaft 8 against the 7 portion of the bearing 6 by the compression spring 4, rotation of the rotary shaft 8 is freely transmitted and the rotary shaft 8 is held without any clearance. On the other hand, in the thrust direction, the rotary table 2 is held by at least three steel balls 6 arranged in the gap between the rotary table 2 and the fixed table 1. Since the steel ball 6 presses the rotary table 2 against the fixed table 1 by the compression spring 7, the clearance between the rotary table 2 and the fixed table 1 in the thrust direction is zero.

As described above, the rotary table 2 is rotatable with respect to the fixed table 1, and the clearance in the radial and thrust directions is maintained at zero, so that highly accurate positioning is possible.

Furthermore, by arranging three or more steel balls 6 under the outer periphery of the rotary table 2, the rotary table 2 becomes strong against the moment load in the thrust direction.

Effects of the Invention According to the present invention, the clearance between the rotary table and the fixed table in both the radial and thrust directions can be reduced to zero, so the rotary table enables highly accurate positioning. Furthermore, since it is supported at three or more points in the thrust direction, it can withstand moment loads in the thrust direction, and also has the following effects. In other words, since it is pressed through a compression spring in the radial and thrust directions,
It can absorb wear and tear and is durable.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a positioning table according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a front sectional view of a conventional positioning table. 1... Fixed table, 2... Rotating table, 3... Steel ball A, 4... Compression spring A, s... Bearing , 6... Steel ball B, 7...
...Compression spring B, 8...Rotation shaft.

Claims (1)

[Claims] A fixed table, a rotating table integrated with a rotating shaft,
A V-shaped bearing attached to a fixed table, an elastic body and a first ball that press the rotating shaft to the bearing, and at least three second balls arranged in a gap between the fixed table and the rotating table. , a positioning table having an elastic body that presses and supports the rotary table against the fixed table via the second ball.