Damping device

• US 6,789,651 B2
• Filed: 03/19/2002
• Issued: 09/14/2004
• Est. Priority Date: 03/29/2001
• Status: Expired due to Fees

• Current Assignee: Mitutoyo Corporation
• Original Assignee: Mitutoyo Corporation
• Inventors: Ogura, Katsuyuki, Takesako, Koji
• Primary Examiner(s): RODRIGUEZ, PAMELA
• Application Number:
  US10/099,991
• Publication Number:
  US 20030006109A1
• Time in Patent Office: 910 Days
• Field of Search: 188/267.1, 188/290, 188/293, 188/378-380, 248/562, 248/566, 248/581, 248/637, 248/638, 384/9, 384/40, 384/45, 384/57, 384/99, 745/72, 745/74
• US Class Current: 188/267.1
• CPC Class Codes: F16F 15/1201 for damping of axial or radial, i.e. non-torsional vibrations F16F15/13107 takes precedence
• CPC Class Codes: F16F 15/167 having an inertia member, e.g. ring
• CPC Class Codes: F16F 15/315 characterised by their supporting arrangement, e.g. mountings, cages, securing inertia member to shaft F16F15/31 takes precedence
• CPC Class Codes: F16F 9/532 Electrorheological [ER] fluid dampers
• CPC Class Codes: Y10T 74/2122 with fluid balancing means

Abstract

This invention is intended to provide a damping device capable of conducting highly precise damping control. To attain this object, this invention is a damping device used in a machine which includes a rotating object and a motor rotating the rotating object, wherein the damping device includes: a vibration damper filled with an electroviscous fluid having a viscosity changing according to a value of a voltage applied to the electroviscous fluid, and rotatably supporting at least a part of the rotating object in the electroviscous fluid; a voltage applicator applying the voltage to the electroviscous fluid in the vibration damper; and a controller controlling an operation of the voltage applicator so that an optimum voltage, at which the viscosity of the electroviscous fluid absorbing a vibration of the rotating object most effectively is obtained, can be applied to the electroviscous fluid in the vibration damper in accordance with a rotating speed of the rotating object.

Claims

1. A damping device used in a machine comprising a movable object and a motor moving said movable object,

the damping device comprising:

a vibration damper filled with an electroviscous fluid having a viscosity changing according to a value of a voltage applied to the electroviscous fluid, and movably supporting at least a part of said movable object in the electroviscous fluid;

a voltage applicator applying the voltage to the electroviscous fluid in said vibration damper;

a controller controlling an operation of said voltage applicator so that an optimum voltage, at which the viscosity of the electroviscous fluid absorbing a vibration of said movable object most effectively is obtained, can be applied to the electroviscous fluid in said vibration damper in accordance with a moving speed of said movable object;

an indicator indicating the moving speed of said movable object; and

a memory storing control information representing a relationship between the moving speed of said movable object and the optimum voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid absorbing the vibration of the movable object most effectively at the moving speed, is obtained in advance, for each expected moving speed of the movable object, wherein;

when said indicator indicates the moving speed of said movable object, said controller indicates said motor to move the movable object at the indicated moving speed, selects the optimum voltage applied to the electroviscous fluid to correspond to the indicated moving speed, and controls the operation of said voltage applicator so that the selected voltage can be applied to the electroviscous fluid in said vibration damper.

2. The damping device according to claim 1, further comprising a rotating object rotating about a rotation axis, wherein:

the motor rotates said rotating object, which moves the movable object;

the vibration damper rotatably supports at least a part of said rotating object in the electroviscous fluid; and

the controller controls the operation of said voltage applicator so that the optimum voltage, at which the viscosity of the electroviscous fluid absorbing the vibration of said rotating object most effectively is obtained, can be applied to the electroviscous fluid in said vibration damper in accordance with the rotating speed of said rotating object.

3. The damping device according to claim 2, further comprising:

a rotating indicator indicating the rotating speed of said rotating object; and

the memory storing control information representing relationship between the rotating speed of said rotating object and the optimum voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid absorbing the vibration of the rotating object most effectively at the rotating speed, obtained in advance, for each expected rotating speed of the rotating object, wherein

when said rotating indicator indicates the rotating speed of said rotating object, said controller indicates said motor to rotate the rotating object at the indicated rotating speed, selects the optimum voltage applied to the electroviscous fluid to correspond to the indicated rotating speed and controls the operation of said voltage applicator so that the selected voltage can be applied to the electroviscous fluid in said vibration damper.

4. The damping device according to claim 3, wherein

said controller selects, from the control information in said memory, the voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid in said vibration damper becomes lower as an indicated value of the rotating speed of the rotating object indicated by said indicator is higher;

and

said controller selects, from the control information in said memory, the voltage applied to the electroviscous fluid at which the viscosity, of the electroviscous fluid in said vibration damper becomes higher as the indicated value of the rotating speed of the rotating object indicated by said indicator is lower.

5. The damping device according to claim 3, comprising:

a detector detecting the rotating speed of said rotating object at real time, wherein

said controller selects the optimum voltage applied to the electroviscous fluid to correspond to the rotating speed detected by said detector from the control information in said memory, and actively controls the operation of said voltage applicator so that the selected voltage can be applied to the electroviscous fluid.

6. The damping device according to claim 5, wherein

said controller selects the voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid in said vibration damper becomes lower as the speed value of the rotating object detected by said detector is higher;

said controller selects the voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid in said vibration damper becomes higher as the speed value of the rotating object detected by said detector is lower; and

said controller actively controls the operation of said voltage applicator in accordance with the rotating speed detected by said detector.

7. The damping device according to claim 2, wherein

said rotating object comprises:

a damping rotation shaft supported in the electroviscous fluid in said vibration damper;

a driving rotation shaft transmitting a driving force from said motor; and

a coupling connecting said damping rotation shaft to said driving rotation shaft, wherein

a rotating force from said driving rotation shaft is surely transmitted to said damping rotation shaft through the coupling, and the coupling absorbs misalignment between the damping rotation shaft and the driving rotation shaft.

8. The damping device according to claim 1, further comprising:

a rotating object rotating about a rotation axis, wherein the motor rotates said rotating object; and

a driving coupling section transforming rotating motion of the rotating object into a linear motion, wherein;

the movable object is provided in the driving coupling section and making the linear motion,

the vibration damper is provided between the driving coupling section and the movable object, and

the movable object makes the linear motion in a state that the movable object is supported in the electroviscous fluid in the vibration damper.

9. A damping device according to claim 8, wherein

said controller selects, from the control information in said memory, the voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid in said vibration damper becomes higher as an indicated value of the moving speed of the movable object indicated by said indicator is higher;

and

said controller selects, from the control information in said memory, the voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid in said vibration damper becomes lower as the indicated value of the moving speed of the movable object indicated by said indicator is lower.

10. A damping device according to claim 8, comprising:

a detector detecting the moving speed of said movable object at real time, wherein

said controller actively selects the optimum voltage applied to the electroviscous fluid to correspond to the moving speed detected by said detector from the control information in said memory, and controls the operation of said voltage applicator so that the selected voltage can be applied to the electroviscous fluid.

11. A damping device according to claim 10, wherein

said controller selects the voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid in said vibration damper becomes higher as the speed value of the movable object detected by said detector is higher;

said controller selects the voltage applied to the electroviscous fluid at which the viscosity of the electroviscous fluid in said vibration damper becomes lower as the speed value of the movable object detected by said detector is lower; and

said controller actively controls the operation of said voltage applicator in accordance with the moving speed detected by said detector.