A NEW-TYPE OF SUPERCONDUCTING BEARING SYSTEM USING HIGH T-C SUPERCONDUCTORS AND THE DYNAMICS

To further the practical use of superconducting bearings, a supercondu cting bearing system using high T-c superconductors has been newly con structed. The superconducting beating system consists of two supercond ucting bearings and a rotor. The rotor is supported by the bearings wi th field-cooled superconductors. Static and dynamic characteristics of the superconducting bearing system are investigated. To evaluate the load capacity of the system, relationships between restoring force and displacements of the rotor in the radial direction and the axial dire ction are investigated. Moreover, to construct a vibration model of th e superconducting bearing system, responses for impulsive forces appli ed in the radial direction of the stationary rotor are measured using an FFT analyzer. The rotor has a maximum speed of 63,000 rpm driven by air force. Spin-down tests are performed to evaluate dynamics of the rotor, after the driving force is cut off. The results show that the d isplacements are smaller than 30 mu m peak to peak at all speeds excep t critical speeds of the system. The bearing system is very well self- centered in the speed range up to 63,000 rpm in our experiments. Since the structure of the superconducting bearing system is very simple an d easy to use, the bearing system is full of promise for industrial ap plications.