Bearing assembly monitoring system

In combination with a support bearing assembly for a driveshaft of a helicopter, the support bearing assembly having at least one bearing, a bearing assembly monitoring system, comprising:

• vibration sensing means for continuously monitoring complex vibrations emanating from the support bearing assembly and providing complex vibration signals corresponding thereto;
• vibration signal processing circuit means operative in response to said complex vibration signals for providing at least one vibration alarm signal, said vibration signal processing circuit means including
• means for filtering said complex vibration signals to pass a predetermined bandwidth of said complex vibration signals,
• means for converting said predetermined bandwidth of said complex vibration signals to DC voltage signals,
• means for generating at least one vibration reference voltage indicative of excessive vibration levels in the bearing support assembly, said at least one vibration reference voltage corresponding to degradation of the support bearing assembly, and
• means for comparing said at least one vibration reference voltage and said DC voltage signals to cause generation of said at least one vibration alarm signal when said DC voltage signals exceed said at least one vibration reference voltage;
• first temperature sensing means for continuously monitoring the operating temperature of each bearing of the support bearing assembly and providing bearing operating temperature signals corresponding thereto;
• second temperature sensing means for continuously monitoring the ambient temperature adjacent the support bearing assembly and providing ambient temperature signals corresponding thereto;
• temperature signal processing circuit means operative in response to said bearing operating and ambient temperature signals for providing a temperature alarm signal, said temperature signal processing circuit means including
• means for transforming said bearing operating temperature signals and said ambient temperature signals to corresponding differential temperature signals,
• means for generating a temperature differential reference voltage corresponding to a predetermined temperature differential indicative of impending catastrophic failure of the support bearing assembly due to excessive operative temperature, and
• means for comparing said differential temperature signals and said differential temperature reference voltage to cause generation of said temperature alarm signal when said differential temperature signals exceed said differential temperature reference voltage;
• and
• alarm subsystem means operative in response to said at least one vibration alarm signal and said temperature alarm signal for providing real time early warning of degradation of the support bearing assembly as a result of fatigue wear thereof due to excessive vibration levels and impending catastrophic failure of the support bearing assembly due to excessive operating temperature therein, respectively.