FIBER OPTIC SENSOR FOR MAGNETIC BEARINGS

摘要

A fiber optic sensor for magnetic bearings includes a stator (12), a rotor (14), and an optical transmit/receive fiber (50) which propagates transmit light (112) which is launched across a gap (15) between the stator and the rotor and which receives reflected light (114) that is reflected off of the rotor (14) and travels along the fiber (50) as the light (116). The gap (15) distance is determined by the change in intensity of the return light (114). The transmit/receive fiber (50) may be located radially through or longitudinally along the stator (12). The receive light (116) is detected by a photodetector (120) which provides an electrical signal to a control circuit (124) which controls electromagnetic coils (31-34) of the magnetic bearing. Alternatively, two separate fibers may be used for the transmit and receive light. Also, time or wavelength multiplexing may be employed to allow for remote optical source and detection/control of the gap (15) distance. Further, a plurality of such sensors may be used around the gap (15). Also, a temperature sensor may be embedded within the distance sensor. Further, radial and/or axial gaps may be measured.