# US 10,864,979 B2 · System and method for propeller feedback ring position detection

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- Number: US 10,864,979 B2
- Document ID: US10864979B2
- Status: Granted
- Kind: B2
- Application number: 16/020,930
- Filed: 2018-06-27
- Published: 2020-01-02
- Granted: 2020-12-15
- Earliest claimed: 2018-06-27
- Assignees: Pratt & Whitney Canada Corp.
- Applicants: Pratt & Whitney Canada Corp.
- Inventors: Joseph Ernesto Marone; Ian Farrell
- Web page: https://patentgrep.com/patent/US10864979B2

## CPC

- B64C 11/301: {characterised by blade position indicating means}
- B64D 45/0005: {Devices specially adapted to indicate the position of a movable element of the aircraft, e.g. landing gear}
- F01D 7/00: Rotors with blades adjustable in operation; Control thereof (for reversing F01D1/30)
- F05D 2260/74: by turning around an axis perpendicular the rotor centre line
- F05D 2260/76: the adjusting mechanism using auxiliary power sources
- B64C: AEROPLANES; HELICOPTERS
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A system and method for determining a position of a feedback ring of a propeller of an aircraft engine are provided. The feedback ring is coupled to the propeller to rotate with the propeller and to be displaced along a longitudinal axis with adjustment of a blade angle. An engagement member is configured to engage the feedback ring and to be displaced along a longitudinal direction substantially parallel to the longitudinal axis with displacement of the feedback ring. A sensor comprises a first member coupled to the engine and a second member coupled to the engagement member. The second member is moveable relative to the first member along the longitudinal direction as the engagement member is displaced. The sensor generates a signal indicative of a longitudinal position of the second member relative to the first member. A controller determines an axial position of the feedback ring from the sensor signal.

## Claims

### Claim 1

A feedback ring position detection system for a propeller of an aircraft engine, the propeller rotatable about a longitudinal axis and having an adjustable blade angle, the system comprising:
a feedback ring coupled to the propeller to rotate with the propeller and to be displaced along the longitudinal axis with adjustment of the blade angle;
an engagement member configured to moveably engage the feedback ring and to be displaced along a longitudinal direction substantially parallel to the longitudinal axis with displacement of the feedback ring;
a sensor comprising a first member coupled to the aircraft engine and a second member coupled to the engagement member, the first member stationary and the second member moveable relative to the first member along the longitudinal direction as the engagement member is displaced, the sensor configured to generate a sensor signal indicative of a longitudinal position of the second member relative to the first member; and
a controller configured to receive the sensor signal and to determine an axial position of the feedback ring along the longitudinal axis based on the longitudinal position of the second member relative to the first member.

### Claim 2 (depends on 1)

The system of claim 1, wherein the feedback ring has a channel formed around a circumference thereof.

### Claim 3 (depends on 2)

The system of claim 2, wherein the engagement member is configured to be retained in the channel.

### Claim 4 (depends on 3)

The system of claim 3, wherein the channel is u-shaped and the engagement member is a block.

### Claim 5 (depends on 1)

The system of claim 1, wherein the sensor is a linear variable differential transformer, the first member comprising a plurality of solenoidal coils and the second member comprising a ferromagnetic core.

### Claim 6 (depends on 1)

The system of claim 1, wherein the first member is secured to a gear box of the aircraft engine.

### Claim 7 (depends on 1)

The system of claim 1, wherein the sensor is configured to generate the sensor signal indicative of a longitudinal displacement of the second member relative to a reference position of the first member.

### Claim 8

An aircraft engine comprising:
a propeller rotatable about a longitudinal axis and having blades with an adjustable blade angle;
a feedback ring coupled to the propeller to rotate with the propeller and to be displaced along the longitudinal axis with adjustment of the blade angle;
an engagement member configured to moveably engage the feedback ring and to be displaced along a longitudinal direction substantially parallel to the longitudinal axis with displacement of the feedback ring;
a sensor comprising a first member coupled to the aircraft engine and a second member coupled to the engagement member, the first member stationary and the second member moveable relative to the first member along the longitudinal direction as the engagement member is displaced, the sensor configured to generate a sensor signal indicative of a longitudinal position of the second member relative to the first member; and
a controller configured to receive the sensor signal and to determine an axial position of the feedback ring along the longitudinal axis based on the longitudinal position of the second member relative to the first member.

### Claim 9 (depends on 8)

The engine of claim 8, wherein the feedback ring has a channel formed around a circumference thereof.

### Claim 10 (depends on 9)

The engine of claim 9, wherein the engagement member is configured to be retained in the channel.

### Claim 11 (depends on 10)

The engine of claim 10, wherein the channel is u-shaped and the engagement member is a block.

### Claim 12 (depends on 8)

The engine of claim 8, wherein the sensor is a linear variable differential transformer, the first member comprising a plurality of solenoidal coils and the second member comprising a ferromagnetic core.

### Claim 13 (depends on 8)

The engine of claim 8, wherein the first member is secured to a gear box of the aircraft engine.

### Claim 14 (depends on 9)

The engine of claim 9, wherein the sensor is configured to generate the sensor signal indicative of a longitudinal displacement of the second member relative to a reference position of the first member.

### Claim 15

A method for determining an axial position of a feedback ring of a propeller of an aircraft engine, the propeller rotatable about a longitudinal axis and having an adjustable blade angle and the feedback ring rotatable with the propeller, the method comprising:
displacing a moveable sensor member relative to a stationary sensor member, the stationary sensor member coupled to the aircraft engine and the moveable sensor member displaceable relative to the stationary sensor member along a longitudinal direction substantially parallel to the longitudinal axis as the feedback ring is displaced along the longitudinal axis;
receiving a sensor signal indicative of a longitudinal position of the moveable sensor member relative to the stationary sensor member; and
determining the axial position of the feedback ring along the longitudinal axis based on the longitudinal position of the moveable sensor member relative to the stationary sensor member as obtained from the sensor signal.

### Claim 16 (depends on 15)

The method of claim 15, wherein the sensor signal is indicative of a longitudinal displacement of the moveable sensor member relative to a reference position of the stationary sensor member.

### Claim 17 (depends on 16)

The method of claim 16, wherein the axial position of the feedback ring is determined based on the longitudinal displacement of the moveable sensor member relative to the reference position of the stationary sensor member.

### Claim 18 (depends on 15)

The method of claim 15, wherein the moveable sensor member comprises a ferromagnetic core of a linear variable differential transformer, and the stationary sensor member comprises a plurality of solenoidal coils of the linear variable differential transformer.