ROTORCRAFT VIBRATION SUPPRESSION SYSTEM IN A FOUR CORNER PYLON MOUNT CONFIGURATION

• US 20130270415A1
• Filed: 01/08/2013
• Published: 10/17/2013
• Est. Priority Date: 01/10/2012
• Status: Active Grant

• Current Assignee: Textron Innovations Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Lee, Taeoh, Heverly, David E. II, Griffin, Maurice, Smith, Michael R., Hendricks, Matthew W.
• Granted Patent: US 9,777,788 B2
• Time in Patent Office: Days
• US Class Current: 248/638
• CPC Class Codes: B64C 2027/002 mounted between the rotor drive and the fuselage
• CPC Class Codes: B64C 27/001 Vibration damping devices
• CPC Class Codes: F16F 13/24 the central part of the unit being supported by one element and both extremities of the unit being supported by a single other element, i.e. double acting mounting
• CPC Class Codes: F16F 7/00 Vibration-dampers; Shock-absorbers using fluid F16F5/00, F16F9/00; specific for rotary systems F16F15/10 ; belt tensioners F16H7/12

Abstract

The vibration suppression system includes a vibration isolator located in each corner in a four corner pylon mount structural assembly. The combination of four vibration isolators, two being forward of the transmission, and two being aft of the transmission, collectively are effective at isolating main rotor vertical shear, pitch moment, as well as roll moment induced vibrations. Each opposing pair of vibration isolators can efficiently react against the moment oscillations because the moment can be decomposed into two antagonistic vertical oscillations at each vibration isolator. A pylon structure extends between a pair of vibration isolators thereby allowing the vibration isolators to be spaced a away from a vibrating body to provide increased control.

Claims

1. A vibration suppression system for an aircraft, comprising:

a pylon mount structural assembly configured to control pitch and roll dynamics of a vibrating body within the aircraft, the pylon mount structural assembly having a pylon structure configured to support the vibrating body at a point of coupling; and

a vibration isolator located at each end of the pylon structure to control the transmission of vibrations through the aircraft, the vibration isolator being spaced away from the vibrating body.

2. The vibration suppression system according to claim 1, wherein the pylon structure is conformed to locate the point of coupling inboard of the vibration isolator.

3. The vibration suppression system according to claim 1, wherein the pylon structure is located above a roof beam.

4. The vibration suppression system according to claim 1, wherein the vibration isolator is spaced away from the vibrating body to be at least one of forward of the vibrating body and aft of the vibrating body.

5. The vibration suppression system according to claim 1, wherein the pylon structure is configured to correlate the motion of the vibrating body by suspending a portion of the vibrating body between a plurality of vibration isolators along the pylon mount.

6. The vibration suppression system according to claim 1, the vibration isolator comprising:

a piston spindle resiliently coupled to an upper housing with an upper elastomer member, the piston spindle being resiliently coupled to a lower housing with a lower elastomer member; and

a spherical bearing assembly having an attachment member, the spherical bearing assembly is located at least partially around the lower housing for coupling to the pylon structure.

7. The vibration isolator according to claim 6, wherein the spherical bearing assembly is located to have a waterline location similar to a driveshaft axis.

8. The vibration isolator according to claim 6, wherein the piston spindle is configured for coupling to the vibrating body.

9. The vibration isolator according to claim 6, wherein the piston spindle is configured for coupling to a pylon assembly of an aircraft.

10. The vibration isolator according to claim 6, wherein the spherical bearing assembly is configured for coupling to a roof structure of an aircraft.

11. The vibration isolator according to claim 1, wherein the vibrating body is at least one of an aircraft engine, an aircraft transmission, an aircraft propeller, or an aircraft rotor.

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

a vibration control system configured to detect and convey vibration data through a plurality of feedback sensors to regulate an isolation frequency of at least one vibration isolator.

13. A pylon mount structural assembly for an aircraft, comprising:

a first pylon structure extending between a first set of vibration isolators, the pylon structure being configured to suspend a portion of a vibrating body between the first set of vibration isolators; and

a second pylon structure extending between a second set of vibration isolators, the pylon structure being configured to suspend a portion of a vibrating body between the second set of vibration isolators;

wherein each pylon structure is formed to locate the vibration isolators away outboard from a point of coupling between the vibrating body and each of the first and the second pylon structure.

14. The pylon mount structural assembly according to claim 13, wherein each vibration isolator includes a spherical bearing assembly having a spherical elastomeric member coupled to the airframe.

15. The pylon mount structural assembly according to claim 14, wherein the spherical elastomeric member is configured to rotationally deform about a center point, the center point lying on a centerline plane of attachment member.

16. The pylon mount structural assembly according to claim 14, wherein the location of the spherical bearing assembly minimizes chucking in the coupling.

17. The pylon mount structural assembly according to claim 13, wherein each set of vibration isolators are separated from the vibrating body increase control the roll and pitch of the vibrating body.

18. The pylon mount structural assembly according to claim 13, further comprising a cross member configured to extend between the first and the second pylon structure.

19. The pylon mount structural assembly according to claim 13, wherein each vibration isolator includes a piston spindle resiliently coupled to an upper housing with an upper elastomer member, the piston spindle being resiliently coupled to a lower housing with a lower elastomer member

20. The pylon mount structural assembly according to claim 19, wherein the piston spindle is configured for coupling to the vibrating body.