United Technologies Corporation

Sikorsky Aircraft Corporation

William C Boyce

Michael W Hawman

Bruce E Zepke

Christopher L Winslow

John A Roncallo

Robert T Bonitz

A system for monitoring the structural condition of a helicopter rotor assembly component includes a piezoelectric sensor. Acoustic emission signal techniques allow for recognizing the relatively high frequency stress waves associated with the propagation of cracks or defects in a rotor assembly component. A signal conditioner processes the sensor signal and provides an output signal that includes at least one characteristic that is indicative of the content of the sensor signal and, therefore, the structural condition of the item of interest. A signal analyzer utilizes the output signal from the signal processor to determine the structural condition of the component.

Structural monitoring system for helicopter rotor components

A bearing assembly monitoring system provides continuous, real time monitoring of the operating condition of a powertrain support bearing assembly and real time alarm signals indicative of degradation and/or impending catastrophic failure thereof. One embodiment of the monitoring system includes a vibration sensing device, first and second primary temperature sensing devices, an ambient temperature sensing device, vibration and temperature signal processing subcircuits, and an alarm subsystem. The vibration sensing device monitors complex vibration signals emanating from the bearing assembly and provides signals corresponding thereto. The vibration signal processing circuit filters such complex vibration signals to provide a predetermined bandwidth thereof that are converted to stabilized DC voltage signals which are compared to reference voltages corresponding to higher than normal and excessive vibration levels. Exceedance of such reference voltages generates a corresponding vibration alarm signal. The temperature sensing devices monitor the operating and ambient temperatures of the bearing assembly and provide signals corresponding thereto. The temperature signal processing circuit converts such temperature signals to differential temperature signals which are compared to a reference voltage corresponding to a temperature differential indicative of impending catastrophic failure. Exceedance of the reference voltage generates a temperature alarm signal. The alarm subsystem is operative in response to the vibration and/or temperature alarm signals to provide a real time early warning of degradation and/or impending catastrophic failure of the bearing assembly.

Bearing assembly monitoring system

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Shelton, CT, United States of America

William C Boyce