# US 2014/0153847 A1 · Hydrostatic guide device and machine tool using the hydrostatic guide device

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- Number: US 2014/0153847 A1
- Document ID: US20140153847A1
- Status: Published application
- Kind: A1
- Application number: 14/089,039
- Filed: 2013-11-25
- Published: 2014-06-05
- Earliest claimed: 2012-12-04
- Assignees: Jtekt Corporation
- Applicants: JTEKT Corporation
- Inventors: Hiroki YAMATO
- Web page: https://patentgrep.com/patent/US20140153847A1

## CPC

- F16C 29/025: {Hydrostatic or aerostatic (this type of bearing for rotary parts F16C32/06)}
- B23Q 1/385: {in which the thickness of the fluid-layer is adjustable}
- F16C 32/0648: {by sensors or pressure-responsive control devices in or near the bearings}
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- B23Q: DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING (tools of the kind used in lathes or boring machines B23B27/00); MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT

## Abstract

A hydrostatic guide device includes: a fixed member having vertical guide faces; a movable member having vertical slide faces; a fluid supply device; a hydrostatic pocket to which a first fluid pressure based on a dimension of a gap is applied, and that urges the movable member with a first urging force; and a hydraulic pocket to which a second fluid pressure based on a dimension of a gap is applied, and that urges the movable member with a second urging force. A variation of the second fluid pressure is smaller than a variation of the first fluid pressure. When the first urging force and the second urging force are balanced with each other in a horizontal direction, the gap between the vertical guide face and the vertical slide face becomes a set value.

## Claims

### Claim 1

A hydrostatic guide device comprising:
a fixed member having a pair of vertical guide faces that face in opposite directions;
a movable member having a pair of vertical slide faces that are opposed to the respective vertical guide faces;
a fluid supply device;
a hydrostatic pocket that is formed in one of the vertical slide faces, the one of the vertical slide faces being opposed to one of the vertical guide faces, the one of the vertical guide faces serving as a reference face, to which a fluid is supplied by the fluid supply device, to which a first fluid pressure based on a dimension of a gap between the one of the vertical guide faces and the one of the vertical slide faces is applied, and that urges the movable member toward the other of the vertical guide faces with a first urging force; and
a hydraulic pocket that is formed in other one of the vertical slide faces, the other of the vertical slide faces being opposed to the other one of the vertical guide faces, to which the fluid is supplied by the fluid supply device, to which a second fluid pressure based on a dimension of a gap between the other one of the vertical guide faces and the other one of the vertical slide faces is applied, and that urges the movable member toward the one of the vertical guide faces with a second urging force, wherein
a variation of the second fluid pressure with respect to a variation of the gap between the other one of the vertical guide faces and the other one of the vertical slide face is smaller than a variation of the first fluid pressure with respect to a variation of the gap between the one of the vertical guide faces and the one of the vertical slide faces, and
when the first urging force and the second urging force are balanced with each other in a horizontal direction, the gap between the one of the vertical guide faces, the one of the vertical guide faces serving as the reference face, and the one of the vertical slide faces becomes a set value.

### Claim 2 (depends on 1)

The hydrostatic guide device according to claim 1, wherein:
an area of the hydrostatic pocket that receives the first fluid pressure is set larger than an area of the hydraulic pocket that receives the second fluid pressure; and
the first fluid pressure is set smaller than the second fluid pressure, based on a ratio between the area of the hydrostatic pocket and the area of the hydraulic pocket.

### Claim 3 (depends on 2)

The hydrostatic guide device according to claim 2, wherein:
the second fluid pressure is a discharge pressure of the fluid supply device; and
the first fluid pressure is a fluid pressure supplied through an orifice provided on a supply passage from the fluid supply device to the hydrostatic pocket.

### Claim 4 (depends on 1)

The hydrostatic guide device according to claim 1, wherein:
the fixed member has a pair of horizontal guide faces outside the vertical guide faces;
the movable member has a pair of horizontal slide faces that are opposed to the respective horizontal guide faces; and
a vertical center position of the hydrostatic pocket is set lower than a vertical center position of the hydraulic pocket.

### Claim 5 (depends on 1)

The hydrostatic guide device according to claim 1, wherein:
the fixed member has a pair of horizontal guide faces outside the vertical guide faces;
the movable member has a pair of horizontal slide faces that are opposed to the respective horizontal guide faces; and
the one of the vertical guide faces and the vertical slide face opposed to the one of the vertical guide faces are formed so as to be inclined so that the movable member is urged downward by a force component of the first urging force.

### Claim 6 (depends on 5)

The hydrostatic guide device according to claim 5, wherein the other one of the vertical guide faces and the vertical slide face opposed to the other one of the vertical guide faces are formed so as to be inclined so that the movable member is urged downward by a force component of the second urging force.

### Claim 7 (depends on 1)

A machine tool including a tool for machining a workpiece, comprising the hydrostatic guide device according to claim 1,
wherein the tool or the workpiece is mounted on the movable member, at a position closer to the reference face than the other one of the vertical guide faces.