Rotor drive system

Patent metadata

Field	Value
Publication number	US-9758245-B2
Application number	US-201414300533-A
Country	US
Kind code	B2
Filing date	Jun 10, 2014
Priority date	Jul 2, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A rotor drive for a tail rotor of a helicopter is provided. The system includes a stator and a rotor mounted to the stator with a rotatable central carrier. Rotor blades are radially attached to the rotatable central carrier and each of the rotor blades is pivotable about their respective radial central axis for variation of blade pitch. At least one permanent magnet is provided on each rotor blade. A plurality of electromagnets is provided on the stator close enough to allow inductive interaction between the plurality of electromagnets and the at least one permanent magnet on each rotor blade. The permanent magnets are offset from the radial central axis in a direction perpendicular to the rotation plane for individual pitch control of the rotor blades by individual control of electric supply to the electromagnets.

First claim

What is claimed is:

1. A rotor drive system of a tail rotor of a helicopter, the rotor drive system comprising:
a stator and a rotor, the rotor being mounted to the stator with a rotatable central carrier and rotor blades radially attached to the rotatable central carrier, the rotor blades defining one rotation plane with a radial central axis of each of the rotor blades and each of the rotor blades being pivotable about their respective radial central axis for variation of blade pitch,
drive means for the rotor, and
pitch control means for the pivotable rotor blades wherein along at least one blade radius at least one permanent magnet is fixed on each rotor blade and a plurality of electromagnets on the stator is provided coaxially on at least one stator radius to allow inductive interaction between the plurality of electromagnets and the at least one permanent magnet on each rotor blade, the at least one permanent magnet offset from the radial central axis of each rotor blade in a direction perpendicular to the rotation plane for individual pitch control of each of the rotor blades by individual control of electric supply to each of the electromagnets.

2. The rotor drive system according to claim 1 , wherein the stator is a ducted fan, the rotor is mounted radially inside the ducted fan, each of the rotor blades is provided with two electrically separated permanent magnets at a tip of each rotor blade, each of the two electrically separated permanent magnets is fixed offset from the radial central axis in the direction perpendicular to the rotation plane on opposed sides to the rotation plane and the electromagnets are provided along two coaxial, electrically separate rings on an inner circumference of the ducted fan next to the tips, each of the separate rings positioned relative to the permanent magnets on one of the opposed sides to allow electrically separate induction of the permanent magnets on both of the opposed sides of each rotor blade.

3. The rotor drive system according to claim 2 , wherein the ducted fan is an anti-torque system for a ducted tail rotor of a helicopter, in a shroud and the drive means for the rotor are the electromagnets of the two coaxial, electrically separate rings on the inner circumference of the ducted fan operated as individually controlled motors.

4. The rotor drive system according to claim 2 , wherein the rotatable central carrier is a driven hub and the electromagnets provided along the two separate rings on the inner circumference of the ducted fan are operated as electrically separated generators for supply of power to electric consumers.

5. The rotor drive system according to claim 3 , wherein the electromagnets are respectively supplied with three phase alternating current.

6. The rotor drive system according to claim 1 , wherein each rotor blade is provided with a magnet blade connector having bilateral ends spaced apart in a direction of rotation with one permanent magnet at each of its bilateral ends, each of the permanent magnets being coincident with the one of the plurality of electromagnets to define at least two separate motors.

7. The rotor drive system according to claim 1 , wherein a shifting system is provided for shifting the electromagnets in a Y HC -direction.

8. The rotor drive system according to claim 1 , wherein the permanent magnets are mounted at the end of a lever rotatable in an axis parallel to a pitch axis wherein the lever is hinged at the permanent magnets.

9. The rotor drive system according to claim 1 , wherein the two permanent magnets define individual tips of the rotor blades.

10. A rotor drive system of a tail rotor of a helicopter, the system comprising:
a shroud defining a circular duct;
a central carrier mounted in the circular duct;
a plurality of rotor blades extending radially from the central carrier and rotatable within the circular duct, a rotation plane defined by a radial central axis of each of the rotor blades, each of the rotor blades being pivotable about a respective radial central axis to vary a blade pitch,
at least one permanent magnet fixed to each of the plurality of rotor blades, and offset from the radial central axis of each blade in a direction perpendicular to the rotation plane; and
a plurality of electromagnets provided on at least one of the shroud and the central carrier and positioned relative to the at least one permanent magnet to allow inductive interaction between the plurality of electromagnets and the at least one permanent magnet on each rotor blade,
wherein electric supply to each of the plurality of electromagnets is controlled individually to vary the blade pitch of each of the plurality of rotor blades individually.

11. The rotor drive system according to claim 10 , wherein the plurality of electromagnets is defined on an inner circumference of the circular duct and the at least one permanent magnet is positioned at a distal tip of each of the rotor blades.

12. The rotor drive system according to claim 10 , wherein the plurality of electromagnets is defined on an outer circumference of the central carrier.

13. The rotor drive system according to claim 10 , further comprising:
two electrically permanent magnets fixed to each of the plurality of rotor blades, each of the two permanent magnets offset from the radial central axis in the direction perpendicular to the rotation plane on opposed sides to the rotation plane,
two coaxial rings defined by the plurality of electromagnets provided on an inner circumference of the circular duct, each of the two coaxial rings on one of the opposed sides of each rotor blade to allow electrically separate induction of each of the two permanent magnets on both of the opposed sides of each rotor blade.

14. The rotor drive system according to claim 10 , wherein the plurality of electromagnets is respectively supplied with three phase alternating current.

15. The rotor drive system according to claim 10 , wherein each of the plurality of rotor blades is provided with a magnet blade connector having bilateral ends spaced apart in a direction of rotation with one permanent magnet at each of its bilateral ends, each of the permanent magnets being coincident with the one of the plurality of electromagnets to define at least two separate motors.

Assignees

• Airbus Helicopters Deutschland GmbH

Inventors

• Ries Tobias

Classifications

• B64C27/82 Primary

  characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor torque or changing direction of rotorcraft · CPC title

• B64C27/72 Primary

  Means acting on blades · CPC title

• B64C27/12

  Rotor drives · CPC title

• B64C2027/8254

  Shrouded tail rotors, e.g. "Fenestron" fans · CPC title