Rotor hub with blade-to-blade dampers attached to the pitch change axis

Patent metadata

Field	Value
Publication number	US-10773798-B2
Application number	US-201715720626-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Sep 29, 2017
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

An aircraft rotor assembly has a yoke and a plurality of rotor blade assemblies coupled thereto. Each of the rotor blade assemblies include a rotor blade, a bearing, and a blade grip coupling the rotor blade to the bearing. Each of the rotor blades is rotatable about a lead-lag axis, flap axis, and a pitch change axis, wherein all the axes intersect within the bearing. Adjacent pairs of rotor blade assemblies are coupled together via a damper assembly that is coupled to the pitch change axis of each of the rotor blade assemblies.

First claim

What is claimed is:

1. An aircraft rotor assembly, comprising:
a yoke configured to be coupled to and rotate with a mast about a mast axis, the yoke defining a plurality of bearing pockets;
a plurality of rotor blade assemblies, each rotor blade assembly comprising:
a rotor blade;
a bearing, wherein the bearing is at least partially disposed within one of the plurality of bearing pockets, the bearing forming a lead-lag hinge with a lead-lag axis that is substantially parallel to the mast axis, a flap hinge with a flap axis that is substantially perpendicular to and intersects the lead-lag axis, and a pitch change hinge with a pitch change axis that is substantially perpendicular to and intersects both the lead-lag axis and the flap axis; and
a blade grip, the blade grip coupling the rotor blade to the bearing, the blade grip including a shaft between the yoke and the rotor blade, wherein the shaft intersects the pitch change axis; and

a plurality of damper assemblies, each of the plurality of damper assemblies including a first end and a second end, the first end of each damper assembly and the second end of an adjacent damper assembly both being connected to a single concentric rod end bearing, each concentric rod end bearing comprising a ball and concentric inner and outer races, each race being connected to either the first end of one of the damper assemblies or to the second end of an adjacent damper assembly, each of the concentric rod end bearings being coupled to the shaft of one of the plurality of blade grips such that a center point of the ball of each of the concentric rod end bearings is approximately coincident to the pitch change axis of each of the plurality of rotor blade assemblies.

2. The aircraft rotor assembly of claim 1 , wherein each of the plurality of damper assemblies do not include another joint between the concentric rod end bearings to which it is attached.

3. The aircraft rotor assembly of claim 1 , wherein the blade grip includes a central portion connecting an upper plate of the blade grip to a lower plate of the blade grip, the central portion being located between the shaft and the rotor blade.

4. The aircraft rotor assembly of claim 1 , further comprising:
a control system for collective and cyclic control of a pitch of each of the plurality of rotor blade assemblies.

5. The aircraft rotor assembly of claim 4 , the control system, comprising:
a pitch horn coupled to each of the blade grips;
a swashplate; and
a pitch link coupled to each of the pitch horns and the swashplate, each of the pitch links being located closer to the mast axis than an outermost surface of the yoke.

6. The aircraft rotor assembly of claim 5 , wherein each of the pitch links is located closer to the mast axis than the outermost portion of the bearing pockets.

7. The aircraft rotor assembly of claim 6 , wherein the yoke is constructed of a composite material.

8. The aircraft rotor assembly of claim 7 , wherein each of the plurality of rotor blade assemblies are able to rotate about the lead-lag hinge by at least 1 degree in a lead direction and at least 1 degree in a lag direction.

9. An aircraft, comprising:
a fuselage;
a powerplant;
a mast coupled to the powerplant; and
a rotor assembly, comprising:
a yoke coupled to the mast and being configured to rotate about a mast axis, the yoke defining a plurality of bearing pockets;
a plurality of rotor blade assemblies, each rotor blade assembly comprising:
a rotor blade;
a bearing, wherein the bearing is at least partially disposed within one of the plurality of bearing pockets, the bearing forming a lead-lag hinge with a lead-lag axis that is substantially parallel to the mast axis, a flap hinge with a flap axis that is substantially perpendicular to and intersects the lead-lag axis, and a pitch change hinge with a pitch change axis that is substantially perpendicular to and intersects both the lead-lag axis and the flap axis; and
a blade grip, the blade grip coupling the rotor blade to the bearing, the blade grip including a shaft between the yoke and the rotor blade, wherein the shaft intersects the pitch change axis; and

a plurality of damper assemblies, each of the plurality of damper assemblies including a first end and a second end, the first end of each of the plurality of damper assemblies and the second end of an adjacent damper assembly both being connected to a single concentric rod end bearing, each concentric rod end bearing comprising a ball and concentric inner and outer races, each race being connected to either the first end of one of the damper assemblies or to the second end of an adjacent damper assembly, each of the concentric rod end bearings being coupled to the shaft of one of the plurality of blade grips such that a center point of the ball of each of the concentric rod end bearings is approximately coincident to the pitch change axis of each of the plurality of rotor blade assemblies.

10. The aircraft of claim 9 , further comprising:
a control system for collective and cyclic control of a pitch of each of the plurality of rotor blade assemblies.

11. The aircraft of claim 10 , the control system, comprising:
a pitch horn coupled to each of the blade grips;
a swashplate; and
a pitch link coupled to each of the pitch horns and the swashplate, each of the pitch links being located closer to the mast axis than an outermost surface of the yoke.

Assignees

• Bell Helicopter Textron Inc
• Bell Textron Inc

Inventors

• Haldeman Andrew Paul
• Hampton Dalton T
• Marshall Bryan
• Stamps Frank Bradley

Classifications

• B64C27/35 Primary

  having elastomeric joints · CPC title

• B64C27/72

  Means acting on blades · CPC title

• B64C27/605

  including swash plate, spider or cam mechanisms · CPC title

• B64C27/48

  Root attachment to rotor head · CPC title

• B64C27/06

  with single rotor · CPC title