ACTIVE VIBRATIONAL DAMPER

• US 20090314129A1
• Filed: 07/23/2009
• Published: 12/24/2009
• Est. Priority Date: 10/20/2004
• Status: Active Grant

• Current Assignee: Dayco IP Holdings, LLC (Dayco Products LLC)
• Original Assignee: Dayco Products LLC
• Inventors: Crist, Robert J.
• Granted Patent: US 8,028,602 B2
• Time in Patent Office: Days
• US Class Current: 74/574.100
• 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 method of controlling vibrations in a vibrating element, the method comprising the steps of:

coupling a vibrating element to a vibration damper comprising a magneto-rheological elastic element and an inertia element, wherein the frequency of the vibration damper is dependent, at least in part, on the shear modulus of the elastic element;

monitoring the vibrations of the vibrating element; and

applying a magnetic field to the magneto-rheological elastic element of the damper based, at least in part, on the monitored vibrations of the vibrating element to control the shear modulus of the elastic element and therefore the frequency of the damper.

2. A method of controlling vibrations in a vibrating element as claimed in claim 1, wherein the vibration damper further comprises a viscous damper portion containing a magneto-rheological viscous fluid, the method further comprising the step of applying a magnetic field to the magneto-rheological viscous fluid based, at least in part, on the monitored vibrations of the vibrating element.

3. A method of controlling vibrations in a vibrating element as claimed in claim 1, wherein the vibrating element is a rotating shaft and wherein the vibrations of the vibrating element comprise torsional vibrations.

9. A method as claimed in claim 1, wherein the inertia element is an annular inertia element comprising an axially extending slot in an outer face thereof.

10. A method as claimed in claim 9, wherein applying the magnetic field includes positioning an electromagnet to produce a magnetic field across the magneto-rheological elastic element when the electromagnet is energized.

11. A method as claimed in claim 10, wherein the slot of the inertia element has received therein at least one of a portion of the electromagnet, a portion of the magneto-rheological elastic element, or a portion of the vibrating element.

4. A method of directly controlling the torsional vibrations of a rotating shaft, the method comprising the steps of:

providing a vibration damper comprising a magneto-rheological elastic element interposed between an inertia element and a hub, the inertia element being elastically coupled to the vibrating element by the magneto-rheological elastic element, wherein the frequency of the vibration damper is dependent, at least in part, on the shear modulus of the elastic element;

coupling the hub of the vibration damper to a rotating shaft for movement therewith;

monitoring the vibrations of the rotating shaft; and

applying a magnetic field to the magneto-rheological elastic element of the damper based, at least in part, on the monitored vibrations of the rotating shaft to control the shear modulus of the elastic element and therefore the frequency of the damper.

5. A method of indirectly controlling the torsional vibrations of a rotating shaft in an engine system, the method comprising the steps of:

providing a vibration damper comprising a magneto-rheological elastic element interposed between an inertia element and a hub, the inertia element being elastically coupled to the vibrating element by the magneto-rheological elastic element, wherein the frequency of the vibration damper is dependent, at least in part, on the shear modulus of the elastic element;

coupling the hub of the vibration damper to a rotating shaft in an engine system for movement therewith;

monitoring the operating conditions of the engine system; and

applying a magnetic field to the magneto-rheological elastic element of the damper based, at least in part, on the monitored operating conditions of the engine system to control the shear modulus of the elastic element and therefore the frequency of the damper.

6. A method of isolating an associated element from the vibrations of a vibrating element, the method comprising the steps of:

providing a vibration damper comprising a magneto-rheological elastic element, wherein the frequency of the vibration damper is dependent, at least in part, on the shear modulus of the elastic element;

interposing the vibration damper between a vibrating element and an associated element to couple the associated element to the vibrating element;

monitoring the vibrations of the associated element; and

applying a magnetic field to the magneto-rheological elastic element of the damper based, at least in part, on the monitored vibrations of the associated element to control the shear modulus of the elastic element and therefore the frequency of the damper.

7. A method of isolating an associated element from the vibrations of a vibrating element, the method comprising the steps of:

providing a vibration damper comprising a magneto-rheological elastic element, wherein the damping value of the vibration damper is dependent, at least in part, on the damping characteristics of the elastic element;

interposing the vibration damper between a vibrating element and an associated element to couple the associated element to the vibrating element;

monitoring the vibrations of the associated element; and

applying a magnetic field to the magneto-rheological elastic element of the damper based, at least in part, on the monitored vibrations of the associated element to control the damping characteristics of the elastic element and therefore the damping value of the damper.

8. A method as claimed in claim 7, wherein the frequency of the vibration damper is dependent, at least in part, on the shear modulus of the elastic element;

and further comprising the step of applying a magnetic field to the magneto-rheological elastic element of the damper based, at least in part, on the monitored vibrations of the associated element to control the shear modulus of the elastic element and therefore the frequency of the damper.