Abstract: In allusion to the complexity in measuring the dynamic stiffness of active magnetic bearings, a simple measurement system of stiffness is established to measure the dynamic stiffness for active magnetic bearings automatically. This system uses digital controller, amplifier, electromagnet of the active magnetic bearings as vibration exciter, eddy sensor of the active magnetic bearings as vibration pickup and a self-developed measurement and analysis system as measurement and analysis instrument. The measurement result of dynamic stiffness for active magnetic bearings is presented, and it shows that this measurement system can take fairly accurate measurement of the dynamic stiffness for magnetic bearings. This measure system can be applied to the measurement of stiffness for other kinds of bearings, and to the system identification.

Key words: Active magnetic bearings (AMB), Digital control, Measurement, Stiffness, Synchronized sample, Crack susceptibility, Laser cladding, Pulsed Nd: YAG laser, Stellite-6, Vanadium carbide, Wear resistance