Rotor blade damage
AssigneeROLLS-ROYCE plc
InventorsArthur L ROWE, Mark N BINNINGTON, Colin J WOODWARD, Paul R THORNTON
Life of this patent
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Abstract
A rotor assembly (30) comprising a rotor (32) having an annular array of rotor blades (34), the rotor mounted to a shaft (38). A phonic wheel (40) coupled to the shaft. A speed sensor (44) axially aligned with the phonic wheel and configured to measure voltage (V), amplitude of the voltage being proportional to clearance (46) between the sensor and phonic wheel. A processor (48) configured to: receive the voltage measurement; derive shaft speed (ω) from the voltage measurement; identify modulation of the voltage amplitude at a frequency which is an integer multiple of the shaft speed; compare voltage amplitude to a threshold; and output a rotor damage signal based on the comparison.
Claims18
A rotor assembly (30) in a gas turbine engine (10), the rotor assembly (30) comprising:
- a rotor (32) having an annular array of rotor blades (34), the rotor mounted to a shaft (38);
- a phonic wheel (40) coupled to the shaft (38);
- a speed sensor (44) axially aligned with the phonic wheel (40) and configured to measure voltage (V), amplitude of the voltage (V) being proportional to clearance (46) between the sensor (44) and phonic wheel (40);
- and
- a processor (48) configured to:
- i. receive the voltage (V) measurement;
- ii. derive shaft speed (ω) from the voltage (V) measurement;
- iii. identify modulation of the voltage (V) amplitude at a frequency which is an integer multiple of the shaft speed (ω);
- iv. compare voltage (V) amplitude to a threshold (56);
- and
- v. output a rotor damage signal based on the comparison.
A method to detect rotor damage in a gas turbine engine (10), the method comprising steps to:
- monitor speed (ω) of a rotor shaft (38) using a phonic wheel (40) and speed sensor (44);
- monitor voltage (V) amplitude from the speed sensor (44),
- identify modulation of the voltage (V) amplitude at a frequency that is an integer multiple of the shaft speed (ω);
- compare the voltage (V) amplitude to a threshold (56);
- and
- declare rotor damage based on the comparison.
Dependencies are inferred from the claim text.