JP2013050154A - Moving guide device using static pressure bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moving guide device using static pressure bearing capable of simplifying a bearing structure including a static pressure bearing and an oil feeding structure to the static pressure bearing, constituting the whole device compact.SOLUTION: A moving body 13 is supported on a guide body 12 via static pressure pockets 14A, 14B, and the moving body 13 is moved by a drive means. A linear motor 15 is used as a drive means. Attracting force or repelling force between a stator 15a and moving element 15b of the linear motor 15 acts as force in an approaching direction of the guide body 12 and the moving body 13 in a part of the static pressure 14A.

Description

  The present invention relates to a movement guide device using a hydrostatic bearing, which is applied when, for example, a machining table is moved and guided in a machine tool.

  Conventionally, for example, a configuration as disclosed in Patent Document 1 has been proposed as a movement guide device using this type of hydrostatic bearing. In this conventional configuration, a slider having a substantially square frame cross section is supported on a slide shaft extending substantially along a single axis so as to be movable in a non-contact state via a hydrostatic bearing. A pair of linear motors including a coil and a magnet for moving the slider are provided between both side surfaces of the slide shaft and both side inner surfaces of the slider. The hydrostatic bearings are provided between the upper and lower outer surfaces of the slide shaft and the upper and lower inner surfaces of the slider, and between the side surfaces of the slide shaft and the inner surfaces of the slider at the vertical position of the linear motor. The slider is moved in the axial direction along the slide axis by the linear motor.

JP-A-63-283835

  However, in this conventional configuration, as described above, the hydrostatic bearings are provided between the upper and lower and left and right opposing surfaces between the slide shaft and the slider. For this reason, the bearing structure using the hydrostatic bearing becomes complicated, and the structure for supplying oil to the hydrostatic bearing becomes complicated, resulting in a problem that the entire apparatus is increased in size.

  The present invention has been made paying attention to such problems existing in the prior art. The purpose is to use a hydrostatic bearing that can simplify the bearing structure including the hydrostatic bearing and the supply structure of lubricating fluid such as oil to the hydrostatic bearing, and that can be configured in a compact size. It is to provide a movement guide device.

  In order to achieve the above object, the present invention provides a moving guide apparatus in which a moving body is supported on a guide body via a hydrostatic bearing, and the moving body is moved by a driving means. As a linear motor, the suction force or the repulsive force between the stator and the moving element of the linear motor was applied as the force in the approaching direction between the guide body and the moving body in the static pressure bearing portion. It is a feature.

  Accordingly, in the movement guide device of the present invention, the suction force between the stator and the mover of the linear motor is configured to act as a force in the approaching direction between the guide body and the mover in the hydrostatic bearing portion. In this case, the hydrostatic bearing between the guide body and the moving body on the side opposite to the installation position of the linear motor can be omitted. In addition, when the repulsive force between the stator and the moving element acts as a force in the approaching direction between the guide body and the moving body in the hydrostatic bearing portion, the guide on the installation position side of the linear motor is used. The hydrostatic bearing between the body and the moving body can be omitted. Therefore, the bearing structure including the hydrostatic bearing and the supply structure of the lubricating fluid to the hydrostatic bearing can be simplified, and the entire apparatus can be configured in a small size.

  As described above, according to the present invention, the structure for supplying the lubricating fluid to the hydrostatic bearing can be simplified, and the entire apparatus can be configured to be small.

Sectional drawing which shows the movement guide apparatus using the hydrostatic bearing of 1st Embodiment. Sectional drawing which shows the movement guide apparatus using the hydrostatic bearing of 2nd Embodiment. Sectional drawing which shows the movement guide apparatus using the hydrostatic bearing of 3rd Embodiment.

(First embodiment)
A first embodiment in which the present invention is embodied in a machining guide device for a machining table of a machine tool will be described below with reference to FIG.

  As shown in FIG. 1, a guide body 12 having a substantially rectangular cross section is disposed on the machine base 11 so as to extend in a direction perpendicular to the drawing sheet along one axis. A movable body 13 constituting a processing table is supported on the guide body 12 so as to be movable in a non-contact state through oil films overflowing from pockets 14A and 14B of a plurality of hydrostatic bearings in a recess 13a on the lower surface thereof. Yes. Between the upper surface of the guide body 12 and the lower surface of the moving body 13, a linear motor 15 is disposed as a driving means for moving the moving body. The linear motor 15 includes a stator 15a made of a coil provided on the guide body 12 side and a mover 15b made of a magnet provided on the moving body 13 side.

  Of the plurality of static pressure pockets 14 </ b> A and 14 </ b> B, a pair of static pressure pockets 14 </ b> A is disposed between the upper surface of the guide body 12 and the lower surface of the moving body 13 on both sides of the linear motor 15. Further, the remaining pair of static pressure pockets 14 </ b> B are disposed between the outer surfaces on both sides of the guide body 12 and the inner surfaces on both sides of the moving body 13. The suction force between the stator 15a and the moving element 15b of the linear motor 15 is configured to act as a force in the approaching direction between the guide body 12 and the moving body 13 at the static pressure pocket 14A. ing. This eliminates the provision of a hydrostatic bearing between the lower surface of the guide body 12 and the moving body 13 on the side opposite to the installation position of the linear motor 15.

  A pair of oil discharge grooves 16 are formed on the upper surface of the guide body 12 between the stator 15a of the linear motor 15 and the pair of static pressure pockets 14A. Then, the oil overflowing from the static pressure pocket 14A is discharged through the oil discharge groove 16. Thereby, infiltration of the oil to the linear motor 15 side is suppressed.

The machine tool according to the embodiment configured as described above operates as follows.
That is, when the machine tool is operated, lubricating oil is supplied to the static pressure pockets 14A and 14B from a hydraulic pressure supply source (not shown), and an oil film is formed between the guide body 12 and the moving body 13. With the operation of the linear motor 15, the oil film is formed sufficiently thin by the suction force between the stator 15a and the mover 15b. Therefore, the moving body 13 is supported with a low load via static pressure and is moved smoothly and with high accuracy, and the oil film is formed extremely thin, so that the positional accuracy of the moving body 13 can be appropriately ensured.

Therefore, according to this embodiment, the following effects can be obtained.
(1) In this movement guide device, the moving body 13 is supported on the guide body 12 via the static pressure pockets 14A and 14B, and the moving body 13 is moved by the linear motor 15 as the driving means. It has become. The suction force or repulsive force between the stator 15a and the moving element 15b of the linear motor 15 acts as a force in the approaching direction between the guiding body 12 and the moving body 13 at the static pressure pocket 14A. It is configured.

  For this reason, the suction force between the stator 15a and the moving element 15b of the linear motor 15 is configured to act as a force in the approaching direction between the guiding body 12 and the moving body 13 at the static pressure pocket 14A. In this case, the hydrostatic bearing between the guide body 12 and the moving body 13 on the side opposite to the installation position of the linear motor 15 can be omitted. In the case where the repulsive force between the stator 15a and the moving element 15b acts as a force in the approaching direction between the guide body 12 and the moving body 13 in the hydrostatic bearing portion, the linear motor 15 It is possible to omit the hydrostatic bearing between the guide body 12 and the moving body 13 on the installation position side. Therefore, the bearing structure including the static pressure pockets 14A and 14B and the oil supply structure to the static pressure pockets 14A and 14B can be simplified, and the entire apparatus can be downsized.

  It is also conceivable that the suction force of the linear motor 15 is not used by providing a static pressure pocket opposite to the static pressure pocket 14A in FIG. However, if this is done, the number of static pressure pockets will increase, and a portion for forming an oil film around the static pressure pockets will be required, resulting in a complicated structure and an increase in size.

(2) In this movement guide device, since the oil film is formed extremely thin, the positional accuracy of the movable body 13 can be ensured appropriately, and high-precision machining of the workpiece becomes possible.
(3) In this movement guide device, an oil discharge groove 16 is formed between the stator 15a of the linear motor 15 and the static pressure pocket 14A, and oil overflowing from the static pressure pocket 14A passes through the oil discharge groove 16. Discharged. Accordingly, the infiltration of oil to the linear motor 15 side is suppressed, and problems with the function of the linear motor 15 are suppressed.

(Second Embodiment)
Next, a second embodiment of a movement guide device using a hydrostatic bearing embodying the present invention will be described with a focus on differences from the first embodiment.

  In the second embodiment, as shown in FIG. 2, a pair of guide bodies 12 having an approximately L-shaped cross section are extended and disposed on the machine base 11 at intervals. On the lower surface of the moving body 13, a pair of grooves 13b having a substantially inverted L-shaped cross section that can be engaged with each guide body 12 is formed. A static pressure pocket 14 </ b> A is disposed between the upper and lower surfaces of each guide body 12 and the opposing inner surface of each groove portion 13 b in the moving body 13. A static pressure pocket 14 </ b> B is disposed between the side surface of one guide body 12 and the inner side surface of one groove portion 13 b in the moving body 13.

  On the side opposite to the static pressure pocket 14B, a linear motor 15 including a stator 15a and a moving element 15b is disposed between the side surface of the other guiding body 12 and the inner surface of the other groove 13b of the moving body 13. ing. The repulsive force between the stator 15a and the moving element 15b of the linear motor 15 is configured to act as a force in the approaching direction between the guiding body 12 and the moving body 13 at the static pressure pocket 14B. ing. Thereby, on the installation position side of the linear motor 15, provision of a hydrostatic bearing between the side surface of the guide body 12 and the inner surface of the groove portion 13 b of the moving body 13 is omitted.

Therefore, also in the second embodiment, it is possible to obtain substantially the same effects as the effects described in (1) and (2) in the first embodiment.
(Third embodiment)
Next, a description will be given of a third embodiment of a movement guide apparatus using a hydrostatic bearing embodying the present invention, centering on differences from the first embodiment.

  In the third embodiment, as shown in FIG. 3, a cylindrical first guide body 12 </ b> A and a columnar second guide body 12 </ b> B are arranged concentrically on the machine base 11. On the first guide body 12A, a disk-shaped moving body 13 constituting a rotary table is fitted and supported by the second guide body 12B so as to be rotatable about an axis at a boss portion 13c on the lower surface. Between the upper surface of the first guide body 12A and the lower surface of the moving body 13, a static pressure pocket 14A is arranged in an annular shape. An annular static pressure pocket 14B is disposed between the outer peripheral surface of the second guide body 12B and the inner peripheral surface of the boss portion 13c of the moving body 13.

  Inside the static pressure pocket 14A, between the upper surface of the first guide body 12A and the lower surface of the moving body 13, a linear motor 15 including a stator 15a and a moving element 15b is arranged in an annular shape. The suction force between the stator 15a and the movable element 15b of the linear motor 15 is configured to act as a force in the approaching direction between the guide body 12 and the movable body 13 in the static pressure pocket 14A. ing. Thereby, it is omitted to provide a hydrostatic bearing between the lower surface of the first guide body 12A and the moving body 13 on the side opposite to the installation position of the linear motor 15.

Therefore, also in the third embodiment, it is possible to obtain substantially the same effect as the effect described in (1) in the first embodiment.
(Example of change)
In addition, this embodiment can also be changed and embodied as follows.

-In each said embodiment, changing the shape structure of the guide bodies 12, 12A, 12B and the mobile body 13 arbitrarily.
The configuration of each of the above embodiments is applied to a moving guide device for a moving body different from a processing table for a machine tool.

  ・ Use air instead of oil as a medium to provide lubrication.

  DESCRIPTION OF SYMBOLS 12 ... Guide body, 12A ... 1st guide body, 12B ... 2nd guide body, 13 ... Moving body, 14A, 14B ... Static pressure bearing, 15 ... Linear motor as drive means, 15a ... Stator, 15b ... Mover .

Claims (1)

In the movement guide device that supports the moving body via a hydrostatic bearing on the guide body and moves the moving body by the driving means,
A linear motor is used as the driving means, and a suction force or a repulsive force between the stator and the moving element of the linear motor is applied as a force in the approaching direction between the guide body and the moving body in the hydrostatic bearing portion. A movement guide device using a hydrostatic bearing characterized by the above.

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