Application Advances in HTS Bearing Technology

Superconducting magnetic bearings (SMB) are of increasing technical interest. Based on passive magnetic levitation and the flux pinning effect of melt textured YBCO a number of SMB modules have been developed and tested in prototype machines. The individual bearing components superconductors and permanent magnets and their interaction is investigated. Characterization experiments are conducted to understand the rotor dynamic behavior and the acting forces. In terms of unbalance and critical speeds the suspended wheels and rotors compare favorably with conventional bearing devices. The rationale of our present bearing technology lies in the assembling of a first 30 000 rpm - centrifuge prototype with complete passive HTS bearings. A high-speed 40 mm rotor of a scanning device is accelerated to 174 000 rpm confirming stable low-drag and low energy operation. Finally, the necessary vacuum and cryogenics technology is discussed. Based on experimental results various cooling solutions are suggested.