Piezo-electric motor for bowed rotor mitigation

Patent metadata

Field	Value
Publication number	US-10208629-B2
Application number	US-201715475855-A
Country	US
Kind code	B2
Filing date	Mar 31, 2017
Priority date	Mar 31, 2017
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

A piezoelectric motor comprising one or more concentric stator rings arranged to transfer energy and provide torque to an engine rotor or to an engine transmission. Such a piezo-electric motor improves spatial integration of an engine turning motor in a gas turbine engine.

First claim

What is claimed is:

1. An aircraft engine assembly, comprising:
a gas turbine engine including a rotor shaft, the rotor shaft having a longitudinal axis;
a nacelle housing the rotor shaft and comprising trapped air creating a temperature gradient perpendicular to the longitudinal axis; and
means for rotating the rotor shaft using a piezoelectric motor, the rotating reducing or preventing thermal bowing of the rotor shaft in the temperature gradient.

2. The aircraft engine assembly of claim 1 , wherein the means further comprises:
the piezoelectric motor comprising one or more stators and one or more rotor members disposed around at least one shaft selected from a rotor shaft and a drive shaft in a transmission connected to the rotor shaft, wherein the rotor members are connected to the at least one shaft; and
a circuit connected to the one or more stators, wherein the rotor rotates when the one or more stators press against the one or more rotor members in response to one or more electric fields applied by the circuit onto the one or more stators.

3. The aircraft engine assembly of claim 2 , wherein:
the electric fields generate one or more traveling waves in the stators, and
the traveling waves press against the one or more rotor members, thereby rotating the one or more rotor members and the rotor shaft connected to the one or more rotor members.

4. The aircraft engine assembly of claim 2 , further comprising a plurality of the stators and a plurality of the rotor members alternately disposed in a stack.

5. The aircraft engine assembly of claim 2 , further comprising a plurality of the stators paired with a surface of one of the rotor members, wherein the plurality of the stators press against different radial positions on the surface.

6. The aircraft engine assembly of claim 2 , further comprising one or more of the stators paired with a surface of one of the rotor members, wherein:
the one or more of the stators each comprise piezoelectric actuators disposed in a concentric ring around the rotor shaft or the drive shaft, and
the actuators sequentially press against the surface when the circuit applies the electric fields to each of the actuators, thereby delivering torque to the surface.

7. The aircraft engine assembly of claim 1 , wherein the means further comprises:
a plurality of piezoelectric actuators disposed on an inner surface of an annulus around the at least one shaft; and
a circuit connected to the actuators, wherein the at least one shaft rotates when the actuators sequentially press against an outer surface of the at least one shaft in response to the electric fields applied by the circuit.

8. An aircraft engine assembly, comprising:
a gas turbine engine including a rotor shaft; and
a piezoelectric motor attached to at least one shaft selected from the rotor shaft and a drive shaft, wherein the piezoelectric motor rotates the rotor shaft in response to one or more electric fields.

9. The aircraft engine assembly of claim 8 , wherein:
the piezoelectric motor comprises one or more stators and one or more rotor members disposed around the at least one shaft,
the rotor members are connected to the at least one shaft; and
the rotor rotates when the one or more stators press against the one or more rotor members in response to the one or more electric fields applied onto the one or more stators.

10. The aircraft engine assembly of claim 9 , wherein:
the electric fields generate one or more traveling waves in the stators, and
the traveling waves press against the one or more rotor members, thereby rotating the one or more rotor members and the rotor shaft connected to one or more rotor members.

11. The aircraft engine assembly of claim 9 , further comprising a plurality of the stators and a plurality of the rotor members alternately disposed in a stack.

12. The aircraft engine assembly of claim 9 , further comprising a plurality of the stators paired with a surface of one of the rotor members, wherein the plurality of the stators press against different radial positions on the surface.

13. The aircraft engine assembly of claim 9 , further comprising one or more of the stators paired with a surface of one of the rotor members, wherein:
the one or more stators each comprise piezoelectric actuators disposed in a concentric ring around the rotor shaft or the drive shaft, and
the actuators sequentially press against the surface in response to the one or more electric fields applied to each of the actuators, thereby delivering torque to the surface.

14. The aircraft engine assembly of claim 8 , wherein:
the piezoelectric motor comprises a plurality of piezoelectric actuators disposed on an inner surface of an annulus around the rotor shaft or the drive shaft, and
the rotor shaft or the drive shaft rotates when the actuators sequentially press against an outer surface of the shaft in response to the one or more electric fields applied to the actuators.

15. A method of rotating a shaft in an aircraft engine, comprising:
obtaining a piezoelectric motor comprising one or more stators and one or more rotor members disposed around at least one shaft selected from a rotor shaft and a drive shaft in an aircraft engine,
driving a shaft in an aircraft engine using a piezoelectric motor, wherein the driving comprises:
connecting the one or more rotor members to the shaft; and
generating one or more traveling waves in the stators such that the traveling waves deliver mechanical output to the one or more rotor members and rotate the rotor shaft or the drive shaft.

16. The method of claim 15 , further comprising rotating the rotor shaft using the piezoelectric motor when the rotor shaft is cooling down in a temperature gradient perpendicular to a longitudinal axis of the rotor shaft, thereby reducing or preventing thermal bowing of the rotor shaft in the temperature gradient.

17. A method of rotating a shaft in an aircraft engine, comprising:
providing a piezoelectric motor comprising actuators paired with a surface of a rotor member; and
connecting the rotor member to at least one shaft in an aircraft engine; and
driving the at least one shaft using the piezoelectric motor, wherein the driving comprises applying one or more electric fields to the actuators such that the actuators press against different radial positions on the surface, delivering torque to the rotor member and the at least one shaft connected to the rotor member.

18. The method of claim 17 ,
wherein the actuators are stators each comprising piezoelectric actuators disposed in a concentric ring around the at least one shaft selected from a rotor shaft and a drive shaft in a transmission connected to the rotor shaft;
wherein the driving further comprises sequentially applying one or more electric fields to the actuators such that the actuators sequentially press against the surface, delivering torque to the rotor member and the at least one shaft connected to the rotor member.

19. The method of claim 17 , wherein:
providing the piezoelectric motor comprising a plurality of the actuators comprising piezoelectric actuators disposed on an inner surface of an annulus around the at least one shaft selected from the rotor shaft and a drive shaft in a transmission connected to the rotor shaft, wherein the driving further comprises sequentially applying one or more electric fields to the actuators such that the actuators sequentially press against an outer surface of the at least one shaft, delivering torque to the at least one shaft.

Assignees

• Boeing Co

Inventors

• Jackowski Jason J
• Karnofski Kent E

Classifications

• H02N2/12

  Constructional details · CPC title

• H02N2/10 Primary

  producing rotary motion, e.g. rotary motors · CPC title

• F02C6/00

  Plural gas-turbine plants; Combinations of gas-turbine plants with other apparatus; Adaptations of gas-turbine plants for special use · CPC title

• F01D25/36 Primary

  using electric motors · CPC title

• F05D2270/114

  by limiting mechanical stresses · CPC title