ARTICULATED MAIN ROTOR HUB WITH INWARDLY CF BEARING AND 3% FLAPPING HINGE OFFSET

• US 20150251753A1
• Filed: 03/10/2014
• Published: 09/10/2015
• Est. Priority Date: 03/10/2014
• Status: Active Grant

• Current Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Jarrett, Chad Lewis, Stamps, Frank Bradley, Shimek, Glenn
• Granted Patent: US 9,764,831 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64C 27/35 having elastomeric joints
• CPC Class Codes: B64C 27/605 including swash plate, spider or cam mechanisms

Abstract

A rotary system including a grip having an opening forming a first bridge for receiving a centrifugal force bearing that faces inwardly towards the rotor mast. A rotor blade couples to the grip and a pitch horn positioned outside the opening pitches the rotor blade during flight. A bearing assembly attaches the first bridge to the yoke and controls blade forces exerted against the hub assembly during flight.

Claims

1. A rotary system for a rotary aircraft, comprising:

a rotor mast;

a swashplate rotatably carried by the rotor mast; and

a hub assembly for securing a rotor blade to the rotor mast, the hub assembly having;

a yoke rigidly attached to the rotor mast, the yoke having;

an upper plate; and

a lower plate;

a blade grip for securing the rotor blade to the yoke, the grip having;

a thickness; and

an opening extending through the thickness, the opening forming a bridge;

wherein the blade grip is operably associated with the swashplate for providing pitching movement of the blade during flight;

a damper pivotally attached to the blade grip and the yoke; and

a bearing assembly configured to attach the blade grip to the yoke;

wherein the bearing assembly controls blade forces exerted against the hub assembly during flight.

2. The rotary system of claim 1, wherein the bearing assembly comprises:

a spherical centrifugal bearing having a conical profile.

3. The rotary system of claim 2, wherein the spherical centrifugal bearing is composed of elastomeric material.

4. The rotary system of claim 3, wherein a focal center of the spherical centrifugal bearing is positioned inwardly towards the rotor mast.

5. The rotary system of claim 4, wherein the focal center of the spherical centrifugal bearing is located at a first distance from the rotor mast;

and

wherein a center of the pivotal attachment between the damper and the yoke is located the first distance from the rotor mast.

6. The rotary system of claim 2, wherein an apex of the spherical centrifugal bearing is positioned towards the rotor mast.

7. The rotary system of claim 2, wherein the spherical centrifugal bearing is asymmetrical shaped.

8. The rotary system of claim 3, further comprising a coning stop.

9. The rotary system of claim 8, the coning stop having:

a weighed first member; and

a second member;

wherein the blade grip rests on the second member during periods of low centrifugal force exerted on the rotary system.

10. The rotary system of claim 2, wherein the spherical centrifugal bearing is composed of a plurality of plies of elastomeric material having a conical shape;

and

wherein an apex of the spherical centrifugal bearing faces the bridge.

11. A rotary system for a rotary aircraft, comprising:

a yoke;

a grip having an opening forming a bridge and rigidly attached to a rotor blade; and

a bearing assembly operably associated with the grip, the bearing assembly being configured to attach the grip to the yoke;

wherein the bearing assembly controls blade forces exerted against the hub assembly during flight.

12. The rotary system of claim 11, the yoke comprising:

an upper plate; and

a lower plate.

13. The rotary system of claim 12, further comprising:

a coning stop.

14. The rotary system of claim 11, the bearing assembly comprising:

a spherical centrifugal bearing having a conical profile.

15. The rotary system of claim 14, wherein a focal center of the spherical centrifugal bearing is positioned towards a center of the yoke.

16. The rotary system of claim 14, wherein the spherical centrifugal bearing is located within the opening of the grip.

17. The rotary system of claim 11, further comprising:

a damper pivotally connecting the yoke to the grip;

wherein a focal center of bearing assembly is located at a blade station equal to a blade station of a center of the pivotal attachment between the damper and the yoke.