Hub bolt supported inboard bearing assemblies

Patent metadata

Field	Value
Publication number	US-10494091-B2
Application number	US-201815990625-A
Country	US
Kind code	B2
Filing date	May 26, 2018
Priority date	Jul 13, 2017
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

A proprotor system for a tiltrotor aircraft having helicopter and airplane flight modes includes a yoke having a plurality of blade arms each having an inboard pocket. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets with each bearing assembly including a bearing cage, a shear bearing and a centrifugal force bearing. Each of a plurality of inboard beams is disposed at least partially between one of the centrifugal force bearings and one of the shear bearings. Each of a plurality of proprotor blades is coupled to one of the inboard beams. Hub bolts couple each of the bearing cages to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assemblies and the yoke inboard of the inboard pockets.

First claim

What is claimed is:

1. A proprotor system for a tiltrotor aircraft having a helicopter flight mode and an airplane flight mode, the proprotor system comprising:
a yoke having a plurality of blade arms including a first blade arm having an inboard pocket;
a bearing assembly disposed at least partially within the inboard pocket, the bearing assembly including a bearing cage, a shear bearing and a centrifugal force bearing;
an inboard beam disposed at least partially between the centrifugal force bearing and the shear bearing;
a proprotor blade coupled to the inboard beam; and
a plurality of hub bolts coupling the bearing cage to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assembly and the yoke inboard of the inboard pocket.

2. The proprotor system as recited in claim 1 wherein the yoke further comprises first and second surfaces and defines a plurality of hub bolt openings extending between the first and second surfaces inboard of the inboard pocket.

3. The proprotor system as recited in claim 2 further comprising a bushing disposed within each of the hub bolt openings of the yoke.

4. The proprotor system as recited in claim 2 wherein the bearing cage further comprises first and second clamp plates each having a plurality of hub bolt openings and a bearing retainer coupled to the centrifugal force bearing.

5. The proprotor system as recited in claim 4 wherein the centrifugal force bearing further comprises an elastomeric element that is vulcanized with the bearing retainer.

6. The proprotor system as recited in claim 4 wherein the bearing cage further comprises a bearing ring coupled to the shear bearing.

7. The proprotor system as recited in claim 6 wherein the shear bearing is bolted to the bearing ring.

8. The proprotor system as recited in claim 4 wherein the centrifugal force bearing is disposed within the bearing retainer.

9. The proprotor system as recited in claim 4 wherein the bearing retainer further comprises a spindle that passes through the centrifugal force bearing and the shear bearing.

10. The proprotor system as recited in claim 4 wherein the inboard beam is coupled to the shear bearing.

11. The proprotor system as recited in claim 4 wherein the first clamp plate and the second clamp plate each has two hub bolt openings.

12. The proprotor system as recited in claim 4 wherein each of the hub bolts passes through aligned hub bolt openings of the first and second clamp plates and the yoke to clamp the bearing cage to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assembly and the yoke inboard of the inboard pocket and maintain a spaced apart relationship between the bearing cage and the inboard pocket to prevent centrifugal force load transfer therebetween.

13. The proprotor system as recited in claim 12 wherein the first clamp plate of the bearing cage has a contact relationship with the first surface of the yoke and the second clamp plate of the bearing cage has a contact relationship with the second surface of the yoke.

14. A proprotor system for a tiltrotor aircraft having a helicopter flight mode and an airplane flight mode, the proprotor system comprising:
a yoke having a plurality of blade arms including a first blade arm having an inboard pocket with an outboard surface and a plurality of hub bolt openings inboard of the inboard pocket;
a bearing assembly disposed at least partially within the inboard pocket, the bearing assembly including a bearing cage with an outboard surface, a shear bearing and a centrifugal force bearing;
an inboard beam disposed at least partially between the centrifugal force bearings and the shear bearing;
a proprotor blade coupled to the inboard beam; and
a plurality of hub bolts coupling the bearing cage to the yoke at the hub bolt openings such that the hub bolts provide centrifugal force load paths between the bearing assembly and the yoke inboard of the inboard pocket and such that there is a spaced apart relationship between the outboard surface of the bearing cage and the outboard surface of the inboard pocket to prevent centrifugal force load transfer therebetween.

15. The proprotor system as recited in claim 14 wherein the bearing cage further comprises first and second clamp plates each having a plurality of hub bolt openings and a bearing retainer coupled to the centrifugal force bearing.

16. The proprotor system as recited in claim 15 wherein the bearing cage further comprises a bearing ring coupled to the shear bearing.

17. The proprotor system as recited in claim 15 wherein the centrifugal force bearing is disposed within the bearing retainer.

18. The proprotor system as recited in claim 15 wherein the bearing retainer further comprises a spindle that passes through the centrifugal force bearing and the shear bearing and wherein the inboard beam is coupled to the shear bearing.

19. The proprotor system as recited in claim 15 wherein each of the hub bolts passes through aligned hub bolt openings of the first and second clamp plates and the yoke to clamp the bearing cage to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assembly and the yoke inboard of the inboard pocket and maintain a spaced apart relationship between the outboard surface of the bearing cage and the outboard surface of the inboard pocket to prevent centrifugal force load transfer therebetween.

20. A tiltrotor aircraft having a helicopter flight mode and an airplane flight mode, the tiltrotor aircraft comprising:
a fuselage;
a wing extending from the fuselage;
first and second pylon assemblies coupled to the wing outboard of the fuselage; and
first and second proprotor systems operably associated respectively with the first and second pylon assemblies, each proprotor system including:
a yoke having a plurality of blade arms including a first blade arm having an inboard pocket;
a bearing assembly disposed at least partially within the inboard pocket, the bearing assembly including a bearing cage, a shear bearing and a centrifugal force bearing;
an inboard beam disposed at least partially between the centrifugal force bearing and the shear bearing;
a proprotor blade coupled to the inboard beam; and
a plurality of hub bolts coupling the bearing cage to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assembly and the yoke inboard of the inboard pocket.

Assignees

• Bell Helicopter Textron Inc
• Bell Textron Inc

Inventors

• Kizhakkepat Amarjit Olenchery
• Wardlaw Robert Patrick
• Mccullough John Richard
• Stamps Frank Bradley
• Baldwin Tyler Wayne

Classifications

• F16C33/22

  Sliding surface consisting mainly of rubber or synthetic rubber (F16C33/24 - F16C33/28 take precedence) · CPC title

• B64C29/0033 Primary

  the propellers being tiltable relative to the fuselage · CPC title

• F16C33/06

  Sliding surface mainly made of metal (F16C33/24 - F16C33/28 take precedence; {casting metal bearing surfaces B22D15/02, B22D19/08}) · CPC title

• F16C17/10

  for both radial and axial load · CPC title

• B64C11/06

  for variable-pitch blades · CPC title