Active vibrational damper

• US 7,584,685 B2
• Filed: 10/20/2004
• Issued: 09/08/2009
• Est. Priority Date: 10/20/2004
• Status: Expired due to Fees

• Current Assignee: Dayco IP Holdings, LLC (Dayco Products LLC)
• Original Assignee: Dayco Products LLC
• Inventors: Crist, Robert J.
• Primary Examiner(s): Johnson; Vicky A
• Application Number:
  US10/969,887
• Publication Number:
  US 20060081086A1
• Time in Patent Office: 1,784 Days
• Field of Search: 745/722, 745/741
• US Class Current: 74/574.1
• CPC Class Codes: F16F 1/361 comprising magneto-rheological elastomers [MR], magneto-rheological fluid dampers F16F9/535
• CPC Class Codes: F16F 15/1442 with a single mass
• CPC Class Codes: Y10T 74/2127 with electrical or magnetic damping

Abstract

A vibration damper and/or isolator for a rotating shaft is provided comprising a hub, an inertia element, a magneto-rheological elastic element interposed between the hub and the inertia element to non-rigidly couple the inertia element to the hub, and an electromagnet operable to produce a magnetic field across the elastic element when energized. The magneto-rheological elastic element, which may comprise a composite of magnetic-responsive particles dispersed within an elastic material, possesses a variable shear modulus that is dependent, at least in part, on the strength of a magnetic field applied to the elastic element.

Claims

1. A vibration damper comprising:

a vibrating element coupled to a rotating shaft for rotational movement therewith;

an annular inertia element having an axially extending slot in an outer face thereof;

a magneto-rheological elastic element interposed between the inertia element and the vibrating element; and

an electromagnet operable to produce a magnetic field across the elastic element when energized;

wherein the inertia element is elastically coupled to the vibrating element by the magneto-rheological elastic element; and

wherein at least one of a portion of the electromagnet, a portion of the magneto-rheological elastic element, or a portion of the vibrating element is located within the slot in the annular inertia element.

2. A vibration damper as claimed in claim 1, wherein the magneto-rheological elastic element comprises a composite of magnetic-responsive particles dispersed within an elastic material.

3. A vibration damper as claimed in claim 2, wherein the magneto-rheological elastic element comprises magnetic-responsive particles in the range of 10 % to 50 % by volume.

4. A vibration damper as claimed in claim 1, wherein the magneto-rheological elastic element possesses a variable elastic modulus that is dependent, at least in part, on the strength of a magnetic field applied to the elastic element.

5. A vibration damper as claimed in claim 1, wherein the magneto-rheological elastic element possesses a variable shear modulus that is dependent, at least in part, on the strength of a magnetic field applied to the elastic element.

6. A vibration damper as claimed in claim 1, further comprising:

a vibration sensor; and

a controller operatively coupled to the vibration sensor for receiving a signal therefrom, wherein the controller is operable to energize the electromagnet based, at least in part, on the signal received from the sensor.

7. A vibration damper as claimed in claim 1, further comprising:

a fluid chamber formed between the inertia element and the associated vibrating element, wherein the chamber contains a viscous fluid to provide viscous damping when the inertia element moves relative to the associated vibrating element.

8. A vibration damper as claimed in claim 7, wherein the viscous fluid is an magneto-rheological fluid and wherein the electromagnet is operable to produce a magnetic field across the fluid when energized.

9. A vibration damper as claimed in claim 1, further comprising:

a fluid chamber defined by the slot of the inertia element, the vibrating element, and the magneto-rheological elastic element, wherein the fluid chamber contains a viscous fluid to provide viscous damping.

10. A vibration damper as claimed in claim 9, wherein the viscous fluid is a magneto-rheological fluid and the electromagnet is operable to produce a magnetic field across the magneto-rheological fluid.

11. A vibration damper as claimed in claim 1, wherein the electromagnet is fixedly mounted and the vibrating element and magneto-rheological elastic element rotate relative to the electromagnet.

12. A vibration damper comprising:

a hub adapted to be coupled to an associated rotating shaft for rotational movement therewith;

an inertia element having a an axially extending slot in an outer face thereof;

a magneto-rheological elastic element interposed between the hub and the inertia element to non-rigidly couple the inertia element to the hub for rotation therewith;

a fluid chamber defined by the slot in the inertia element, the hub, and the magneto-rheological elastic element, the fluid chamber containing a magneto-rheological fluid; and

an electromagnet operable to produce a magnetic field across the magneto-rheological elastic element and the magneto-rheological fluid.

13. A vibration damper as claimed in claim 12, wherein the magneto-rheological elastic element comprises a composite of magnetic-responsive particles dispersed within an elastic material.

14. A vibration damper as claimed in claim 13, wherein the magneto-rheological elastic element comprises magnetic-responsive particles in the range of 10 to 50 % by volume.

15. A vibration damper as claimed in claim 14, wherein the elastic material of the elastic element comprises either natural or synthetic rubber.

16. A vibration damper as claimed in claim 12, wherein the magneto-rheological elastic element possesses a variable elastic modulus that is dependent, at least in part, on the strength of a magnetic field applied to the elastic element.

17. A vibration damper as claimed in claim 12, wherein the magneto-rheological elastic element possesses a variable shear modulus that is dependent, at least in part, on the strength of a magnetic field applied to the elastic element.

18. A vibration damper as claimed in claim 12, further comprising:

a vibration sensor; and

a controller operatively coupled to the vibration sensor for receiving a signal therefrom, wherein the controller is operable to energize the electromagnet based, at least in part, on the signal received from the sensor.

19. A vibration damper as claimed in claim 12, further comprising:

a fluid chamber formed between the inertia element and the hub, wherein the chamber contains a viscous fluid to provide viscous damping when the inertia element moves relative to the hub.

20. A vibration damper as claimed in claim 19, wherein the viscous fluid is an magneto-rheological fluid and wherein the electromagnet is operable to produce a magnetic field across the fluid when energized.

21. A vibration damper as claimed in claim 12, wherein at least one of a portion of the electromagnet, a portion of the magneto-rheological elastic element, or a portion of the vibrating element is located within the slot in the inertia element.

22. A vibration damper as claimed in claim 12, wherein the electromagnet is fixedly mounted and the hub rotates relative to the electromagnet.