Multiple-Yoke Main Rotor Assembly

• US 20130149151A1
• Filed: 12/13/2011
• Published: 06/13/2013
• Est. Priority Date: 12/13/2011
• Status: Active Grant

• Current Assignee: Textron Innovations Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Rauber, Richard E., Stamps, Frank B., Popelka, David A., Tisdale, Patrick R., Wood, Tommie L.
• Granted Patent: US 8,985,951 B2
• Time in Patent Office: Days
• US Class Current: 416/141
• CPC Class Codes: B64C 27/43 see-saw type, i.e. two-bladed rotor
• CPC Class Codes: B64C 29/0033 the propellers being tiltable relative to the fuselage

Abstract

The present application includes a main rotor assembly for an aircraft. The rotor assembly has a main rotor mast configured for rotation about a mast axis and two yokes pivotally connected to the mast for rotation therewith about the mast axis. Each yoke is independently pivotable relative to the mast about at least one flap axis that is generally perpendicular to the mast axis. In at least one embodiment, a torque splitter connects the yokes and allows for limited rotation of the yokes relative to each other about the mast axis. Each yoke is configured for the attachment of rotor blades extending generally radially relative to the mast axis.

Claims

1. A main rotor assembly for an aircraft, the rotor assembly comprising:

a main rotor mast configured for rotation about a mast axis;

two yokes pivotally connected to the mast for rotation therewith about the mast axis, each yoke being independently pivotable relative to the mast about at least one flap axis generally perpendicular to the mast axis;

wherein each yoke is configured for the attachment of rotor blades extending generally radially relative to the mast axis.

2. The rotor assembly of claim 1, wherein the flap axes are spaced from each other along a length of the mast axis.

3. The rotor assembly of claim 1, wherein the flap axes are angularly oriented about the mast axis so that the flap axes are perpendicular to each other.

4. The rotor assembly of claim 1, wherein the flap axes are angularly oriented about the mast axis so that the flap axes are non-perpendicular to each other.

5. The rotor assembly of claim 1, wherein each yoke is connected to the mast with a teetering configuration, allowing each yoke to pivot relative to the mast about one associated flap axis.

6. The rotor assembly of claim 1, wherein each yoke is connected to the mast with a gimbal configuration, allowing each yoke to pivot relative to the mast about at least two associated flap axes.

7. The rotor assembly of claim 1, further comprising:

a sleeve for connecting each yoke to the mast, each sleeve having a pivot for defining one flap axis.

8. The rotor assembly of claim 1, further comprising:

a sleeve for connecting each yoke to the mast, each sleeve having a pivot for defining one flap axis; and

a torque splitter connecting the sleeves and transferring torque from the mast to the sleeves, the torque splitter allowing for limited rotation of the sleeves relative to each other about the mast axis.

9. A main rotor assembly for an aircraft, the rotor assembly comprising:

a main rotor mast configured for rotation about a mast axis;

two yokes pivotally connected to the mast for rotation therewith about the mast axis, each yoke being independently pivotable relative to the mast about at least one flap axis generally perpendicular to the mast axis;

a torque splitter connecting the yokes and transferring torque from the mast to the yokes, the torque splitter allowing for limited rotation of the yokes relative to each other about the mast axis;

wherein each yoke is configured for the attachment of rotor blades extending generally radially relative to the mast axis.

10. The rotor assembly of claim 9, wherein the flap axes are spaced from each other along a length of the mast axis.

11. The rotor assembly of claim 9, wherein the flap axes are angularly oriented about the mast axis so that the flap axes are perpendicular to each other.

12. The rotor assembly of claim 9, wherein the flap axes are angularly oriented about the mast axis so that the flap axes are non-perpendicular to each other.

13. The rotor assembly of claim 9, wherein each yoke is connected to the mast with a teetering configuration, allowing each yoke to pivot relative to the mast about one associated flap axis.

14. The rotor assembly of claim 9, wherein each yoke is connected to the mast with a gimbal configuration, allowing each yoke to pivot relative to the mast about at least two associated flap axes.

15. The rotor assembly of claim 9, further comprising:

a sleeve for connecting each yoke to the mast, each sleeve having a pivot for defining one corresponding flap axis, the torque splitter connecting the sleeves and allowing for limited rotation of the sleeves relative to each other about the mast axis.

16. An aircraft having a main rotor assembly, the aircraft comprising:

a main rotor mast configured for rotation about a mast axis;

two yokes pivotally connected to the mast for rotation therewith about the mast axis, each yoke being independently pivotable relative to the mast about at least one flap axis generally perpendicular to the mast axis;

a torque splitter connecting the yokes and transferring torque from the mast to the yokes, the torque splitter allowing for limited rotation of the yokes relative to each other about the mast axis;

wherein each yoke is configured for the attachment of rotor blades extending generally radially relative to the mast axis.

17. The aircraft of claim 16, wherein the flap axes are spaced from each other along a length of the mast axis.

18. The aircraft of claim 16, wherein each yoke is connected to the mast with a teetering configuration, allowing each yoke to pivot relative to the mast about one associated flap axis.

19. The aircraft of claim 16, wherein each yoke is connected to the mast with a gimbal configuration, allowing each yoke to pivot relative to the mast about at least two associated flap axes.

20. The aircraft of claim 16, further comprising:

a sleeve for connecting each yoke to the mast, each sleeve having a pivot for defining one corresponding flap axis, the torque splitter connecting the sleeves and allowing for limited rotation of the sleeves relative to each other about the mast axis.