# US 11,306,955 B2 · Method of monitoring a shutdown cycle of an air cycle machine of an aircraft

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- Number: US 11,306,955 B2
- Document ID: US11306955B2
- Status: Granted
- Kind: B2
- Application number: 16/401,914
- Filed: 2019-05-02
- Published: 2020-11-05
- Granted: 2022-04-19
- Earliest claimed: 2019-05-02
- Assignees: Simmonds Precision Products, Inc.
- Applicants: Simmonds Precision Products, Inc.
- Inventors: Bernard Dion; Brian R. Shea; Peter Zywiak; Jeffrey J. Nieter
- Web page: https://patentgrep.com/patent/US11306955B2

## CPC

- F25B 49/02: for compression type machines, plants or systems
- B64D 13/02: the air being pressurised
- F25B 9/004: {the refrigerant being air}
- G01M 13/04: Bearings
- F05D 2260/80: Diagnostics
- F25B 2500/27: characterised by the stop of the refrigeration cycle
- F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A method of monitoring an air cycle machine including driving a rotary shaft of an air cycle machine, disconnecting a driving source to allow the rotary shaft to slow the rotary shaft, and monitoring a shutdown cycle of the rotary shaft.

## Claims

### Claim 1

A method of monitoring an air cycle machine of an aircraft comprising:
driving a rotary shaft of an air cycle machine;
disconnecting a driving source to allow the rotary shaft to slow the rotary shaft;
extrapolating a shutdown cycle data and estimating when a shutdown cycle time will breach a predetermined threshold; and
monitoring a shutdown cycle of the rotary shaft.

### Claim 2 (depends on 1)

The method of claim 1, wherein the monitoring further includes monitoring time required for the rotary shaft to slow to a selected rotational velocity from an operational rotational velocity.

### Claim 3 (depends on 1)

The method of claim 1, further comprising communicating monitored data to a controller and performing an action in response to shutdown cycle times breaching a selected threshold.

### Claim 4 (depends on 1)

The method of claim 1, wherein monitoring takes place during a ramp down period of air cycle machine operation.

### Claim 5 (depends on 1)

The method of claim 1, wherein the monitoring step lasts at least 30 seconds.

### Claim 6 (depends on 5)

The method of claim 5, wherein the monitoring step includes a sampling rate of between 1 and 2 samples per second.

### Claim 7 (depends on 1)

The method of claim 1, wherein at least one sensor operatively connected to the rotary shaft monitors the shutdown cycle of the rotary shaft.

### Claim 8 (depends on 7)

The method of claim 7, further comprising monitoring at least two ramp down cycle times.

### Claim 9 (depends on 7)

The method of claim 7, further comprising monitoring multiple shutdown cycles.

### Claim 10 (depends on 9)

The method of claim 9, further comprising monitoring changes between shutdown cycles.

### Claim 11 (depends on 7)

The method of claim 7, further comprising performing an action with respect to the air cycle machine prior to a shutdown cycle time reaching the predetermined threshold.

### Claim 12 (depends on 11)

The method of claim 11, wherein the action includes sending an alert to a flight crew or maintenance crew of an aircraft on which the air cycle machine is included.

### Claim 13 (depends on 11)

The method of claim 11, wherein the action includes removal of the air cycle machine from operation.