| 摘要 |
976,176. Bearings. MAGNETFABRIK BONN G.m.b.H. June 17, 1963 [June 16, 1962], No. 23990/63. Heading F2A. [Also in Division G1] In an electricity meter (see Division G1) a rotatable member 11 comprises a cylindrical portion 17 of diamagnetic material such as bismuth or carbon which lies in the air-gap 15 between the chamfered edges of a cup 13 and a polepiece 14 of magnetic material, the field in the gap due to a permanent magnet 12 being non-homogeneous and freely suspending the rotatable member, which also comprises a conductive disc portion 18. In order to eliminate air friction, the rotatable member may be enclosed in an hermetically closed housing which is evacuated or filled with a low viscosity gas such as hydrogen. |
