Dynamic Characteristics Of The Magnetic Bearing System With The Damper

A magnetic damper is introduced into the ordinary magnetic bearing system to increase the supporting damp. Dynamic characteristics of the system with the damper are studied in the paper. The main contents and conclusions are summarized as follows:Each part of the system is presented, and the mathematic models of the system without damper and with the damper are established. The theoretic analysis shows that the damper has obvious effects on the dynamic characteristics of the system, including the stability, the natural frequencies, the mode shapes, and the unbalance response. The damper can increase the supporting damp and help the system to get across the first and the second bending critical speed.The theoretic analysis also shows that the gyroscopic effect, the time constant of the sensor and the time constant of the power amplifier have obvious influence on the dynamic characteristics of the system. The gyroscopic effect can increase the stability of the system; however the time constant has bad influence on the stability of the system.The experiment table is developed, and the above analysis is demonstrated by the Experimental Modal Analysis and actual operation of the experiment table. The rotor can get across the first and the second bending critical speed safely, and can operate on 18,000 rotations per minute.