Starter air valve system with dual electromechanical controls

Patent metadata

Field	Value
Publication number	US-10669945-B2
Application number	US-201715425043-A
Country	US
Kind code	B2
Filing date	Feb 6, 2017
Priority date	Feb 6, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

According to an aspect, a system includes a starter air valve in fluid communication with an air turbine starter to drive motoring of a gas turbine engine responsive to a compressed air flow from a compressed air source. The system also includes a variable-position electromechanical device operable to adjust positioning of the starter air valve and a discrete-position electromechanical device operable to adjust positioning of the starter air valve and limit a motoring speed of the gas turbine engine below a resonance speed of the gas turbine engine responsive to a pulse width modulation control based on a failure of the variable-position electromechanical device.

First claim

What is claimed is:

1. A system of a gas turbine engine, the system comprising:
an air turbine starter coupled to a rotor shaft of the gas turbine engine;
a starter air valve comprising a valve plate configured to provide fluid communication between a compressed air source and the air turbine starter;
a pneumatic actuator in fluid communication with the compressed air source and coupled to the valve plate to establish a valve-controlled starter air flow to the air turbine starter based on a compressed air flow from the compressed air source;
a discrete-position electromechanical device in fluid communication with the pneumatic actuator and configured to control delivery of a portion of the compressed air flow to adjust positioning of the valve plate using the pneumatic actuator;
a variable-position electromechanical device in fluid communication with the discrete-position electromechanical device and the pneumatic actuator, the variable-position electromechanical device configured to control delivery of the portion of the compressed air flow to adjust positioning of the valve plate using the pneumatic actuator; and
a controller coupled to the discrete-position electromechanical device and the variable-position electromechanical device, the controller comprising a processor and memory programmed with a plurality of instructions executable by the processor to cause the controller to command a pulse width modulation of the discrete-position electromechanical device, responsive to a failure of the variable-position electromechanical device, to limit a motoring speed of the gas turbine engine below a resonance speed of the gas turbine engine based on a detected motoring speed of the gas turbine engine, wherein the pulse width modulation alternates a sequence of on and off commands to dither the pneumatic actuator about a target setting to achieve a partially open position of the valve plate.

2. The system as in claim 1 , wherein the compressed air source is an auxiliary power unit, a ground cart, or a cross-engine bleed.

3. The system as in claim 1 , wherein the variable-position electromechanical device is positioned in a pneumatic flow path between the discrete-position electromechanical device and the pneumatic actuator, and the variable-position electromechanical device defaults to an open position.

4. The system as in claim 3 , wherein the variable-position electromechanical device is a torque motor, and the discrete-position electromechanical device is a solenoid.

5. The system as in claim 1 , wherein further configured to dynamically command the variable-position electromechanical device and to command pulse width modulation of the discrete-position electromechanical device based on one or more of: the motoring speed of the gas turbine engine and a speed of the air turbine starter.

6. A gas turbine engine comprising:
a starting spool coupled to a gearbox;
an air turbine starter coupled to the gearbox;
a starter air valve comprising a valve plate configured to provide fluid communication between a compressed air source and the air turbine starter;
a pneumatic actuator in fluid communication with the compressed air source and coupled to the valve plate to establish a valve-controlled starter air flow to the air turbine starter based on a compressed air flow from the compressed air source;
a discrete-position electromechanical device in fluid communication with the pneumatic actuator and configured to control delivery of a portion of the compressed air flow to adjust positioning of the valve plate using the pneumatic actuator;
a variable-position electromechanical device in fluid communication with the discrete-position electromechanical device and the pneumatic actuator, the variable-position electromechanical device configured to control delivery of the portion of the compressed air flow to adjust positioning of the valve plate using the pneumatic actuator; and
a controller coupled to the discrete-position electromechanical device and the variable-position electromechanical device, the controller comprising a processor and memory programmed with a plurality of instructions executable by the processor to cause the controller to command a pulse width modulation of the discrete-position electromechanical device, responsive to a failure of the variable-position electromechanical device, to limit a motoring speed of the gas turbine engine below a resonance speed of the gas turbine engine based on a detected motoring speed, wherein the pulse width modulation alternates a sequence of on and off commands to dither the pneumatic actuator about a target setting to achieve a partially open position of the valve plate.

7. The gas turbine engine as in claim 6 , wherein the compressed air source is an auxiliary power unit, a ground cart, or a cross-engine bleed.

8. The gas turbine engine as in claim 6 , wherein the variable-position electromechanical device is positioned in a pneumatic flow path between the discrete-position electromechanical device and the pneumatic actuator, and the variable-position electromechanical device defaults to an open position.

9. The gas turbine engine as in claim 8 , wherein the variable-position electromechanical device is a torque motor, and the discrete-position electromechanical device is a solenoid.

Assignees

• United Technologies Corp
• Raytheon Tech Corp

Inventors

• Greenberg Michael D
• Gelwan David
• Clauson Jesse W
• Goodman Robert
• Dehais John M
• Kelly Myles R

Classifications

• F02C7/277 Primary

  the starter being a {separate} turbine · CPC title

• F05D2260/4031

  as in toothed gearing · CPC title

• F05D2260/57

  using servos, independent actuators, etc. · CPC title

• F05D2270/02

  to control rotational speed (n) · CPC title

• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title