| 摘要 |
1,186,663. Electric motors. -GENERAL ELECTRIC CO. 20 Feb., 1968 [24 March, 1967], No. 8185/68. Heading H2A. [Also in Division F1] A pump for cryogenic liquids, e.g. liquid helium, has a piston 1 of superconductive material, e.g. niobium, suspended out of contact with the working chamber walls by electromagnetic flux generated by coils 6 to 9, and reciprocated by passing A.C. current through coils 18, 19, which act on a piston flange 4 of superconductive material. Flux loss in coils 18, 19 is avoided by the provision of a superconducting ring 20 having a radial slot. A weak D.C. current is maintained in coils 18, 19 to prevent contact by flange 4 at the end of each stroke. Holes 5 in flange 4 permit passsage of leakage liquid in space 17 during reciprocation. |
