Machine tool

Patent metadata

Field	Value
Publication number	US-9579763-B2
Application number	US-201214110711-A
Country	US
Kind code	B2
Filing date	Aug 30, 2012
Priority date	Aug 30, 2011
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A machine tool including: a table disposed on a saddle movable along an X-axis; a pair of linear motors that moves the table along a Y-axis; position detectors that detect a first position and a second position of the table on the Y-axis; a pair of guide rails attached to the saddle; and four bearings engaged with the pair of guide rails, is provided. The machine tool includes a connecting unit connecting the table to the four bearings such that the table is rotatable relative to the four bearings, and a control unit that controls the pair of linear motors on the basis of the first and second positions.

First claim

What is claimed is:

1. A machine tool, comprising:
a saddle movable along a first axis;
a table disposed on the saddle and movable along a second axis orthogonal to the first axis;
a first linear motor installed at one side of the saddle along a direction of the first axis and moving the table along the second axis, wherein the first linear motor comprises a first mover and a first stator, the first mover is attached to a bottom surface of the table, and the first stator is attached to a top surface of the saddle, and a predetermined gap is formed between the first mover and the first stator;
a second linear motor installed in parallel to the first linear motor with an interval therebetween at the other side of the saddle along the direction of the first axis and moving the table along the second axis, wherein the second linear motor comprises a second mover and a second stator, the second mover is attached to the bottom surface of the table, and the second stator is attached to the top surface of the saddle, and a predetermined gap is formed between the second mover and the second stator;
a first position detector detecting a first position of the table in the second axis at the one side of the saddle along the direction of the first axis;
a second position detector detecting a second position of the table in the second axis at the other side of the saddle along the direction of the first axis;
a first guide rail installed at one side of the saddle along the direction of the first axis and extending in a direction of the second axis;
a second guide rail installed at the other side of the saddle along the direction of the first axis and extending in the direction of the second axis;
at least two first bearings engaged with the first guide rail;
at least two second bearings engaged with the second guide rail;
a connecting unit, wherein the table is fixed to the at least two first bearings and the at least two second bearings in the direction of the first axis through the connecting unit, so that the table is rotatable around a vertical axis relative to the direction of the first axis and the direction of the second axis, and wherein the table is rotatable relative to the saddle by having the connecting unit as a support; and
a control unit controlling the first linear motor based on the first position and controlling the second linear motor based on the second position.

2. The machine tool according to claim 1 , wherein the control unit comprises a target position computer, which generates a target position for the first linear motor and the second linear motor to make the first position and the second position consistent with each other.

3. The machine tool according to claim 1 , wherein the connecting unit comprises a table base, which is attached to the at least two first bearings and the at least two second bearings, and a rotation bearing, which connects the table to a center of the table base in a rotatable way.

4. The machine tool according to claim 3 , wherein the connecting unit further comprises a roller that is rotatable around the center of the table base.

5. The machine tool according to claim 3 , further comprising at least four rollers that are disposed right above the at least two first bearings and the at least two second bearings to sandwich the table base therebetween.

6. The machine tool according to claim 3 , wherein the control unit comprises a target position computer, which generates a target position for the first linear motor and the second linear motor to make the first position and the second position consistent with each other.

7. The machine tool according to claim 1 , wherein the connecting unit comprises a flexible spacer, which connects the table to the at least two first bearings and the at least two second bearings in a rotatable way.

8. The machine tool according to claim 7 , wherein the flexible spacer has a slit for bending the flexible spacer in the direction of the first axis.

9. The machine tool according to claim 7 , further comprising a third bearing, which is disposed between the at least two first bearings and engaged with the first guide rail, and a fourth bearing, which is disposed between the at least two second bearings and engaged with the second guide rail, wherein the connecting unit comprises a fixing spacer that fixes the table to the third bearing and the fourth bearing.

10. The machine tool according to claim 7 , wherein the control unit comprises a target position computer, which generates a target position for the first linear motor and the second linear motor to make the first position and the second position consistent with each other.

11. The machine tool according to claim 1 , wherein the connecting unit comprises a table base, which is attached to the at least two first bearings and the at least two second bearings, and a flexible spacer, which connects the table to the table base in a rotatable way.

12. The machine tool according to claim 11 , wherein the flexible spacer has a slit for bending the flexible spacer in a direction around a center of the table base.

13. The machine tool according to claim 11 , wherein the control unit comprises a target position computer, which generates a target position for the first linear motor and the second linear motor to make the first position and the second position consistent with each other.

Assignees

• Hosaka Akio
• Sodick Co Ltd

Inventors

• Hosaka Akio

Classifications

• G03F7/70758

  Drive means, e.g. actuators, motors for long- or short-stroke modules or fine or coarse driving · CPC title

• B23Q1/621 Primary

  a single sliding pair followed perpendicularly by a single sliding pair · CPC title

• B23Q5/28

  Electric drives · CPC title

• G03F7/70716

  Stages · CPC title

• G03F7/70725

  control · CPC title