HARRY C RIPPEL
Engineers in Delaware

4526484, Jul 2, 1985

Sep 21, 1983

6/534415

Philip Stahl - Holliston MA
Dudley D. Fuller - Lake Hill NY
Harry C. Rippel - Sharon Hill PA

Ferrofluidics Corporation - Nashua NH

F16C 3382

384133

A ferrofluid thrust and radial bearing assembly for a rotatable shaft element, which assembly comprises: a housing characterized by a shaft-receiving space, to define a radial bearing inner surface and a thrust bearing surface at the one end of the shaft-receiving space; a shaft element within the shaft-receiving space, one end of the shaft element disposed to rotate on the thrust bearing surface, and the other end of the shaft extending from the other end of the housing; a ferrolubricant in the shaft-receiving space, to form a lubricant for the thrust bearing and the radial bearing assembly; and a ferrofluid exclusion seal at the other end of the housing and about the other end of the shaft-receiving space, the exclusion seal comprising an annular permanent magnet and at least one annular pole piece, one end of which extends into a close, noncontacting relationship with the exterior surface of the shaft, to form a radial gap, and the ferrofluid within the shaft-receiving space defining a ferrofluid seal at the other end and about the shaft element, so as to retain the ferrofluid within the shaft-receiving space of the housing during the bearing operation.