Elastomeric bearing having tapered layers

Patent metadata

Field	Value
Publication number	US-9334048-B2
Application number	US-201314029906-A
Country	US
Kind code	B2
Filing date	Sep 18, 2013
Priority date	Sep 18, 2013
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A rotor hub for an aircraft that includes a yoke, a rotor mast; and a hub spring assembly. The hub spring assembly includes an upper outer member; an upper inner member; and an upper spring member having a plurality of elastomeric layers and shim layers sandwiched between the upper outer member and the upper inner member, the shim layers being tapered such that a thickness of each shim layer is smaller at a side portion as compared to the thickness of the shim at a center portion.

First claim

The invention claimed is:

1. A rotor hub for an aircraft, the rotor hub comprising:
a yoke;
a rotor mast; and
a hub spring assembly, comprising:
an upper outer member;
an upper inner member; and
an upper spring member having a plurality of elastomeric layers and shim layers sandwiched between the upper outer member and the upper inner member, the shim layers being tapered such that a thickness of each shim layer is smaller at a side portion as compared to the thickness at a center portion;
wherein the shim layers are shaped with an arc taper such that the most interior portions of the shim layers and the most exterior portions of the shim layers have smaller thickness as compared to a center portion of the shim layers.

2. The rotor hub according to claim 1 , further comprising:
a trunnion;
a pillow block;
wherein torque is carried between the yoke and the rotor mast via the trunnion and the pillow block.

3. The rotor hub according to claim 2 , wherein the upper outer member is a rigid member that is coupled to the yoke through the pillow block.

4. The rotor hub according to claim 1 , the hub spring assembly further comprising:
a lower outer member;
a lower inner member; and
a lower spring member having a plurality of elastomeric layers and shim layers sandwiched between the lower outer member and the lower inner member, the shim layers being tapered such that a thickness of each shim layer is smaller at a side portion as compared to the thickness at a center portion.

5. The rotor hub according to claim 4 , wherein the lower outer member is a rigid member that is coupled to the yoke.

6. The rotor hub according to claim 4 , wherein the lower outer member and the upper outer member are coupled together and coupled to the yoke.

7. The rotor hub according to claim 4 , wherein the upper inner member and the lower inner member each having a partial spherical surface at a common radius.

8. The rotor hub according to claim 1 , wherein the plurality of elastomeric layers and shim layers are tapered with an arc geometry.

9. The rotor hub according to claim 1 , wherein the hub spring assembly is configured to react thrust loads, shear loads, and moment loads during operation of the aircraft.

10. The rotor hub according to claim 1 , wherein the aircraft is a tiltrotor aircraft.

11. The rotor hub according to claim 1 , wherein the aircraft is a helicopter.

12. The rotor hub according to claim 1 , wherein the rotor hub is a main rotor hub for a helicopter.

Assignees

• Bell Helicopter Textron Inc

Inventors

• Burnett Michael C

Classifications

• B64C27/35 Primary

  having elastomeric joints · CPC title

• F16C27/063

  Sliding contact bearings · CPC title

• F16F1/41

  the spring consisting of generally conically arranged elements {(if sleeve-like, i.e. a surface of revolution F16F1/3935)} · CPC title