Conduction Cooled High-Temperature Superconducting Magnetic Bearing Module
We have designed, built and tested a prototype of a conduction cooled HTSC bearing module. A superconducting ring, measuring ∅ 102 mm × 13 mm high was assembled from HTSC bulk material. Total mass is 547 g. Lifting force and stability at 77 K and 2 mm gap are approximately 150 N and 80 N/mm, respectively. The superconductor is integrated on a metallic cold plate. Modelling has been used for evaluation of thermal losses and optimization of the cryogenic design. For the present module, total losses at 0.01 Pa insulation vacuum are as small as 1 W, mainly due to radiation. Based on the thermal model the scaling behavior with respect to thermal losses as a function of maximum lifting capability was evaluated. The cooling power was found to be equivalent to about 400 mW electrical power per kg of levitated mass which compares quite favorably to the typical 0.1 …1 W per kg for conventional active magnetic bearings. Details of both experimental work and modelling will be reported.
KeywordsLevitation Force Magnetic Bearing Cooling Power Total Heat Transfer Cold Plate
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- 2.FZK Internet Online Product Information: www.infp.fzk.de/wheel/english/home.htmGoogle Scholar
- 3.S. Gauss and S. Elschner, Levitation and magnetic properties of melt processed high temperature superconductor cylinders, in “Proceed. 4th Int. Symp. Magn. Bearings,” G. Schweitzer, R. Siegwart, and R. Herzog, eds, Zürich, Switzerland, (1994), p.435.Google Scholar
- 5.FZK Test Bench Model TB-STML-ZM04Google Scholar
- 6.“VDI Wärmeatlas,”Verein Deutscher Ingenieure, Düsseldorf, Germany (1991)Google Scholar
- 7.“Handbuch Kryotechnik BW 41–07-03,” VDI Bildungswerk, Düsseldorf, Germany (1975).Google Scholar
- 8.K. Gieck. “Technische Formelsammlung,” Gieck Verlag, Heilbronn, Germany (1989).Google Scholar