Inner member for main rotor centrifugal force bearing
A back-to-back spherical bearing assembly for a rotary system of a rotary aircraft includes a spherical bearing member having an interior cavity and a spherical bearing surface defining a bearing focal point, a first elastomeric and a second elastomeric bonded to the spherical bearing surface on opposite sides of the bearing focal point, an inboard attachment bonded to the first elastomeric and configured to be secured to a rotor hub of the rotary system, and an outboard attachment bonded to the second elastomeric and configured to be secured to a rotor blade of the rotary system.
1. A back-to-back spherical bearing, comprising:
a spherical bearing member having an interior cavity and a spherical bearing surface defining a bearing focal point; and
a first elastomeric and a second elastomeric bonded to the spherical bearing surface on opposite sides of the bearing focal point;
wherein a distance from the bearing focal point to any point on the spherical bearing surface is identical;
wherein the spherical bearing member has a first opening and a second opening formed opposite each other in the spherical bearing surface into the interior cavity;
wherein the first opening, the interior cavity, and the second opening form a throughbore.
2. The back-to-back spherical bearing of claim 1 , wherein the spherical bearing member is a metal member.
3. The back-to-back spherical bearing of claim 2 , wherein one of the first elastomeric or the second elastomeric is positioned over the first opening.
4. The back-to-back spherical bearing of claim 2 , wherein one of the first elastomeric or the second elastomeric is positioned over the second opening.
5. The back-to-back spherical bearing of claim 1 , further comprising:
a first plug closing the first opening, the first plug having an outer surface that is contoured to match the spherical bearing surface; and
a second plug closing the second opening, the second plug having an outer surface that is contoured to match the spherical bearing surface.
6. The back-to-back spherical bearing of claim 1 , wherein the spherical bearing member is a metal member formed of two or more interconnected portions fully enclosing the interior cavity.
7. The back-to-back spherical bearing of claim 1 , wherein the spherical bearing member is a continuous chopped fiber composite member.
8. A back-to-back spherical bearing assembly for a rotary system of a rotary aircraft, the back-to-back spherical bearing assembly comprising:
a spherical bearing member having an interior cavity and a spherical bearing surface defining a bearing focal point;
a first elastomeric and a second elastomeric bonded to the spherical bearing surface on opposite sides of the bearing focal point;
an inboard attachment bonded to the first elastomeric and configured to be secured to a rotor hub of the rotary system; and
an outboard attachment bonded to the second elastomeric and configured to be secured to a rotor blade of the rotary system;
wherein a distance from the bearing focal point to any point on the spherical bearing surface is identical;
wherein the spherical bearing member comprises an opening formed in the spherical bearing surface into the interior cavity, the opening being closed with a plug having an outer surface that is contoured to match the spherical bearing surface.
9. The back-to-back spherical bearing assembly of claim 8 , wherein the spherical bearing member is a metal member formed of two or more interconnected portions fully enclosing the interior cavity.
10. The back-to-back spherical bearing assembly of claim 8 , wherein the spherical bearing member is a continuous chopped fiber composite member.
11. The back-to-back spherical bearing assembly of claim 10 , wherein the interior cavity contains a second material having a lower density than the continuous chopped fiber composite member.
12. The back-to-back spherical bearing assembly of claim 8 , wherein one of the first elastomeric or the second elastomeric is positioned over the opening.
13. The back-to-back spherical bearing assembly of claim 8 , wherein the inboard attachment is secured to the rotor hub and the outboard attachment is secured to the rotor blade, whereby in operation of the rotary system the back-to-back spherical bearing assembly reacts flapping and feather motion of the rotor blade and centrifugal force load.