System for electromechanical pitch actuation for a turbine engine propeller

Patent metadata

Field	Value
Publication number	US-10766604-B2
Application number	US-201715849464-A
Country	US
Kind code	B2
Filing date	Dec 20, 2017
Priority date	Dec 21, 2016
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

A pitch actuation system for a turbine engine propeller includes an actuator with movable part configured to rotate the blades of the propeller relative to the blade pitch axes. The actuator includes a transmission screw that is rotatable and movable in translation along a longitudinal axis, and a nut that engages the screw to move in translation along the longitudinal axis to adjust the pitch of the propeller blades. The actuator further includes non-rotatable decoupler for decoupling the rotation between the propeller and the nut. A blade feathering device has at least one electric drive motor and is configured to translate a member along the longitudinal axis. A blade pitch control device includes at least one electric motor configured to drive a rotor about the longitudinal axis, wherein that rotation rotates the screw and transmits translation of the member.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A pitch actuation system for a turbine engine propeller, comprising an actuator having a main transmission screw configured to be connected to blades of the propeller to rotate said blades relative to blade pitch axes, wherein the actuator is an electromechanical actuator comprising:
the main transmission screw that is rotatable and movable in translation along a longitudinal axis;
a main nut through which said main transmission screw passes and which engages the main transmission screw to move in translation along the longitudinal axis;
a decoupling means comprising a ring surrounding the main nut, a first rolling bearing and a second rolling bearing, the first rolling bearing being mounted between the ring and the main nut, the second rolling bearing being mounted between the ring and an element configured to be connected to the blades, the decoupling means being configured such that when the main nut moves in translation, the pitch of the propeller blades changes but rotation of the propeller does not rotate the main nut;
a blade pitch control means, comprising at least one electric motor configured to drive a first rotor about the longitudinal axis, the main transmission screw being rotated by said first rotor; and
a blade feathering means, comprising at least one electric motor configured to drive a second rotor about the longitudinal axis, and a transmission device comprising a first member that is rotated by said second rotor and a second member that engages said first member to move in translation along the longitudinal axis,
wherein the blade pitch control means are configured to transmit to the main transmission screw the translation of the second member of the transmission device of the blade feathering means.

2. The system according to claim 1 , wherein at least one electric motor of the blade feathering means is configured to have a resisting reluctance torque that prevents the first member of the transmission device of the blade feathering means from rotating.

3. The system according to claim 1 , wherein said at least one electric motor of the blade feathering means comprises a stator supported by a first immovable casing, and said at least one electric motor of the blade pitch control means comprises a stator supported by a second casing that is mounted solely so as to slide in translation along the longitudinal axis within the first immovable casing.

4. The system according to claim 1 , wherein the main transmission screw is connected to an external ring gear of a first planetary reduction gear, the first rotor being connected to a planetary shaft of said first planetary reduction gear, and/or the first member of the transmission device of the blade feathering means is connected to an external ring gear of a second planetary reduction gear, the second rotor being connected to a planetary shaft of said second planetary reduction gear.

5. The system according to claim 4 , wherein said blade pitch control means comprise at least one first electric motor configured to drive the first rotor, and a controller programmed to control said at least one first electric motor to apply a resisting torque that prevents the main transmission screw from rotating when the blade feathering means are activated.

6. The system according to claim 5 , wherein said first electric motor of the blade pitch control means is an asynchronous motor.

7. The system according to claim 1 , wherein the blade pitch control means comprise at least one mechanical device configured to prevent the main transmission screw from rotating, which mechanical device is arranged to engage when said at least one electric motor of said blade pitch control means is not applying any torque to the first rotor and to unlock as a result of axial forces exerted by said at least one electric motor on the first rotor.

8. The system according to claim 1 , wherein the blade pitch control means comprise at least one electric motor arranged to have a resisting reluctance torque that prevents the main transmission screw from rotating.

9. The system according to claim 1 , wherein each of said blade pitch control means and said blade feathering means comprises a first and a second electric motor for driving the same rotor, the first electric motor, being controlled by a controller programmed to control the blade pitch, the second electric motor being controlled by the controller to feather the blades.

10. The system according to claim 9 , wherein the first electric motor is a synchronous motor and the second electric motor is an asynchronous motor.

11. A turbine engine comprising a propeller, the blades of which are variable-pitch blades, and a system according to claim 1 , wherein the main nut drives a member that engages eccentrics provided on plates, the eccentrics supporting and rotating the blades.

12. The turbine engine according to claim 11 , wherein the turbine engine is a turboprop engine.

13. A method for actuating the pitch of the blades of a turbine engine propeller with a system according to claim 1 , the method comprising the steps of:
adjusting the blade pitch by actuating the at least one electric motor of the blade pitch control means, in such a way that rotation of the first rotor leads to rotation of the main transmission screw,
feathering the blades by actuating the at least one electric motor of the blade feathering means, in such a way that rotation of the second rotor causes the main transmission screw to move axially.

14. The system according to claim 1 , wherein the first member of the transmission device is a nut, and the second member of the transmission device is a screw.

Assignees

• Safran Aircraft Engines

Inventors

• De Wergifosse Huguette

Classifications

• F05D2260/79

  Bearing, support or actuation arrangements therefor · CPC title

• F01D7/00

  Rotors with blades adjustable in operation; Control thereof (for reversing F01D1/30) · CPC title

• F05D2260/74

  by turning around an axis perpendicular the rotor centre line · CPC title

• F05D2270/09

  to cope with emergencies · CPC title

• B64C11/44

  electric · CPC title