Electric actuator for engine control

Patent metadata

Field	Value
Publication number	US-9816390-B2
Application number	US-201514789218-A
Country	US
Kind code	B2
Filing date	Jul 1, 2015
Priority date	Jul 1, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

An electric actuator for control of an engine includes an electric motor coupled to a drive shaft that extends to align a gear interface of the electric actuator with a variable geometry adjustment interface of the engine. A position feedback shaft extends coaxially with respect to the drive shaft. The position feedback shaft is coupled to an output shaft of the gear interface at a gear interface end of the position feedback shaft. A rotational position sensor is coupled to a motor end of the position feedback shaft proximate the electric motor. The drive shaft and the position feedback shaft are sized to position an output ring gear of the output shaft in contact with the variable geometry adjustment interface within a casing of the engine and to further position the electric motor and the rotational position sensor external to the casing of the engine.

First claim

What is claimed is:

1. An electric actuator for control of an engine, the electric actuator comprising:
an electric motor coupled to a drive shaft that extends to align a gear interface of the electric actuator with a variable geometry adjustment interface of the engine;
a position feedback shaft that extends coaxially with respect to the drive shaft, wherein the position feedback shaft is coupled to an output shaft of the gear interface at a gear interface end of the position feedback shaft; and
a rotational position sensor coupled to a motor end of the position feedback shaft proximate the electric motor, wherein the drive shaft and the position feedback shaft are sized to position an output ring gear of the output shaft in contact with the variable geometry adjustment interface within a casing of the engine and to further position the electric motor and the rotational position sensor external to the casing of the engine.

2. The electric actuator according to claim 1 , further comprising a retracting mechanism configured to selectively retract the drive shaft and a portion of the gear interface to decouple the drive shaft from the output shaft.

3. The electric actuator according to claim 2 , wherein the gear interface further comprises a wave generator operatively coupled to the drive shaft and a flex gear interposed between the wave generator and the output shaft.

4. The electric actuator according to claim 3 , wherein the flex gear is configured to move between a deformed state and a free state, and the flex gear is in the free state when the wave generator is in a retracted condition.

5. The electric actuator according to claim 2 , wherein the retracting mechanism is a disconnect solenoid, and the wave generator is the portion of the gear interface.

6. The electric actuator according to claim 1 , wherein the variable geometry adjustment interface is operable to adjust a flow path geometry axially downstream of a combustor of the engine in response to rotation of the output ring gear.

7. The electric actuator according to claim 6 , wherein the drive shaft and the position feedback shaft extend radially to align the gear interface of the electric actuator with the variable geometry adjustment interface, and the position feedback shaft is concentrically positioned within the drive shaft.

8. An electric actuation system for an engine comprising:
a first electric actuator comprising:
a first electric motor coupled to a first drive shaft that extends to align a first gear interface of the first electric actuator with a variable geometry adjustment interface of the engine;
a first position feedback shaft that extends coaxially with respect to the first drive shaft, wherein the first position feedback shaft is coupled to a first output shaft of the first gear interface at a first gear interface end of the first position feedback shaft; and
a first rotational position sensor coupled to a first motor end of the first position feedback shaft proximate the first electric motor, wherein the first drive shaft and the first position feedback shaft are sized to position a first output ring gear of the first output shaft in contact with the variable geometry adjustment interface within a casing of the engine and to further position the first electric motor and the first rotational position sensor external to the casing of the engine; and

a second electric actuator comprising:
a second electric motor coupled to a second drive shaft that extends to align a second gear interface of the second electric actuator with the variable geometry adjustment interface of the engine;
a second position feedback shaft that extends coaxially with respect to the second drive shaft, wherein the second position feedback shaft is coupled to a second output shaft of the second gear interface at a second gear interface end of the second position feedback shaft; and
a second rotational position sensor coupled to a second motor end of the second position feedback shaft proximate the second electric motor, wherein the second drive shaft and the second position feedback shaft are sized to position a second output ring gear of the second output shaft in contact with the variable geometry adjustment interface within the casing of the engine and to further position the second electric motor and the second rotational position sensor external to the casing of the engine.

9. The electric actuation system according to claim 8 , wherein the first electric actuator further comprises a first retracting mechanism configured to selectively retract the first drive shaft and a portion of the first gear interface to decouple the first drive shaft from the first output shaft; and the second electric actuator further comprises a second retracting mechanism configured to selectively retract the second drive shaft and a portion of the second gear interface to decouple the second drive shaft from the second output shaft.

10. The electric actuation system according to claim 9 , wherein the first gear interface further comprises a first wave generator operatively coupled to the first drive shaft and a first flex gear interposed between the first wave generator and the first output shaft; and the second gear interface further comprises a second wave generator operatively coupled to the second drive shaft and a second flex gear interposed between the second wave generator and the second output shaft.

11. The electric actuation system according to claim 10 , wherein the first flex gear and the second flex gear are configured to move between a deformed state and a free state, wherein the first flex gear is in the free state when the first wave generator is in a retracted condition, and the second flex gear is in the free state when the second wave generator is in the retracted condition.

12. The electric actuation system according to claim 9 , wherein the first retracting mechanism and the second retracting mechanism are each a disconnect solenoid, the first wave generator is the portion of the first gear interface, and the second wave generator is the portion of the second gear interface.

13. The electric actuation system according to claim 8 , wherein the variable geometry adjustment interface is operable to adjust a flow path geometry axially downstream of a combustor of the engine in response to rotation of one or more of the first output ring gear and the second output ring gear.

14. The electric actuation system according to claim 13 , wherein the first drive shaft and the first position feedback shaft extend radially to align the first gear interface of the first electric actuator with the variable geometry adjustment interface; the first position feedback shaft is concentrically positioned within the first drive shaft; the second drive shaft and the second position feedback shaft extend radially to align the second gear interface of the second electric actuator with the variable geometry adjustment interface; and the second position feedback shaft is concentrically positioned within the second drive shaft.

15. A method of installing an electric actuator in an engine, comprising:
positioning a gear interface of the electric actuator within a casing of the engine such that an output ring gear of an output shaft of the gear interface contacts a variable geometry adjustment interface of the engine;
passing a drive shaft and a position feedback shaft through the casing, wherein the position feedback shaft is concentrically positioned within the drive shaft; and
positioning an electric motor and a rotational position sensor external to the casing of the engine, wherein the electri

Assignees

• Hamilton Sundstrand Corp

Inventors

• Bloxham Keith
• Balsiger Derick S

Classifications

• F05D2240/60

  Shafts · CPC title

• F01D17/162

  for axial flow, i.e. the vanes turning around axes which are essentially perpendicular to the rotor centre line (F01D17/167 takes precedence) · CPC title

• F05D2270/62

  Electrical actuators · CPC title

• F05D2250/90

  Variable geometry · CPC title

• F05D2260/40

  Transmission of power · CPC title