Magnetic bearing incorporating capacitive monitor for high-speed shaft

摘要

A high-speed shaft is supported in a radial magnetic bearing having a fixed stator wound with salient poles dimensioned to provide a radial airgap with a concentric magnetic rotor secured to the shaft. A shaft deflection sensor is formed by a capacitive assembly comprising a measurement electrode (1) and guard electrode (4) within a stable mechanical bearer (2) positioned centrally between pole pieces. Sensor signals are brought out to a surrounding ring-shaped terminal board at the side of the bearing where deflections identified by amplitude, sign and phase enable the characteristic oscillatory modes of the shaft to be determined and any tendency to resonate anticipated.