Method and Apparatus for Improved Vibration Isolation

• US 20110316207A1
• Filed: 03/12/2009
• Published: 12/29/2011
• Est. Priority Date: 03/12/2009
• Status: Active Grant

• Current Assignee: Textron Innovations Incorporated (Textron Inc)
• Original Assignee: Textron Innovations Incorporated (Textron Inc)
• Inventors: Smith, Michael R., Stamps, Frank B.
• Granted Patent: US 9,297,439 B2
• Time in Patent Office: Days
• US Class Current: 267/140.15
• CPC Class Codes: B64C 2027/002 mounted between the rotor drive and the fuselage
• CPC Class Codes: B64C 2027/005 using suspended masses
• CPC Class Codes: B64C 27/001 Vibration damping devices
• CPC Class Codes: F16F 15/027 comprising control arrangements F16F15/0237 takes precedence
• CPC Class Codes: F16F 2224/0283 piezoelectric; electro- or magnetostrictive
• CPC Class Codes: F16F 7/108 on plastics springs

Abstract

A vibration isolator having a housing defining a fluid chamber, piston assembly, tuning passage, and a switchable fluid path assembly for changing the isolation frequency of the vibration isolator. The piston assembly is resiliently disposed within the housing. A vibration tuning fluid is allowed to flow within the housing. Actuation of a valve in the switchable fluid path assembly selectively controls fluid flow within the fluid path of the switchable fluid path assembly.

Claims

1. A vibration isolator, comprising:

a housing defining a fluid chamber having opposing ends;

a fluid disposed within the fluid chamber;

a piston assembly resiliently disposed within the housing;

a tuning passage defined by the piston assembly, for providing fluid communication between the ends of the fluid chamber; and

a switchable fluid path assembly in fluid communication with the fluid chamber for changing the isolation frequency.

2. The vibration isolator according to claim 1, wherein the switchable fluid path assembly comprises:

a fluid path providing fluid communication between each end of the fluid chamber; and

a valve for selectively controlling fluid flow in the fluid path.

3. The vibration isolator according to claim 1, wherein the piston is resiliently coupled to the housing with at least one elastomer member.

4. The vibration isolator according to claim 1, further comprising:

at least one additional switchable fluid path assembly for providing at least one additional isolation frequency.

5. The vibration isolator according to claim 4, wherein each switchable fluid path assembly comprises:

a fluid path providing fluid communication between each end of the fluid chamber; and

a valve for selectively controlling fluid flow in each fluid path.

6. The vibration isolator according to claim 2, wherein the switchable fluid path assembly further comprises:

a valve actuator operably associated with the valve for selectively adjusting fluid flow in the fluid path.

7. The vibration isolator according to claim 6, wherein the valve actuator is an actuation device selected from the group consisting of:

an electric actuator;

a hydraulic actuator;

a pneumatic actuator;

an electromagnetic actuator; and

a shape memory alloy.

8. The vibration isolator according to claim 1, wherein the housing is configured for coupling to a roof beam of an aircraft.

9. The vibration isolator according to claim 1, wherein the piston assembly is configured for coupling to a pylon assembly of an aircraft.

10. The vibration isolator according to claim 1, wherein the fluid has a low viscosity and a high density.

11. A vibration isolator, comprising:

a housing defining a fluid chamber having opposing ends;

a fluid disposed within the isolator;

a piston assembly resiliently disposed within the isolator;

a tuning passage defined by the piston assembly, for providing fluid communication between the ends of the fluid chamber; and

a switchable fluid path assembly in fluid communication with the fluid chamber for changing the isolation frequency;

at least one tuning element operably associated with at least one of the upper fluid chamber and the lower fluid chamber; and

an actuating piston coupled to each tuning element for amplifying the displacement of the fluid in the corresponding fluid chamber.

12. The vibration isolator according to claim 11, wherein the switchable fluid path assembly comprises:

a fluid path providing fluid communication between each end of the fluid chamber; and

a valve for selectively controlling fluid flow in the fluid path.

13. The vibration isolator according to claim 11, wherein each tuning element is electrically coupled via electrical leads to control circuitry for controlling the actuation of actuating pistons.

14. The vibration isolator according to claim 11, wherein the tuning fluid has a low viscosity and a high density.

15. The vibration isolator according to claim 11, wherein the tuning element comprises a material selected from the group consisting of:

piezoceramic;

magnetostrictive; and

electromagnetic.

16. A method of changing an isolation frequency in a vibration isolator, comprising:

providing a housing defining a fluid chamber;

resiliently disposing a piston within the housing, the piston forming a tuning passage within the fluid chamber;

operably associating a switchable fluid path assembly for changing the isolation frequency of the vibration isolator; and

selectively actuating a valve in the switchable fluid path assembly, thereby changing the isolation frequency of the vibration isolator.

17. The method according to claim 16, further comprising:

operably associating at least one additional switchable fluid path assembly for providing at least one additional isolation frequency.

18. The method according to claim 16, further comprising the step of:

providing at least one tuning element operably associated with at least one tuning chamber; and

selectively actuating a piston coupled to each tuning element for amplifying the displacement of a fluid in the fluid chamber.