US 6,982,510 B1 | ||
Low profile fluid dynamic bearing | ||
Anthony Joseph Ajello, Aptos, Calif. (US); Klaus Dieter Kloeppel, Watsonville, Calif. (US); and Gregor Paco Flores, Felton, Calif. (US) | ||
Assigned to Seagate Technology LLC, Scotts Valley, Calif. (US) | ||
Filed on Mar. 13, 2002, as Appl. No. 10/99,205. | ||
Claims priority of provisional application 60/342681, filed on Dec. 20, 2001. | ||
Int. Cl. H02K 7/09 (2006.01); H02K 21/22 (2006.01) |
U.S. Cl. 310—90 | 28 Claims |
1. A fluid dynamic bearing comprising a shaft supporting a hub at one end, the shaft being adapted to rotate within a sleeve supported from a base, the base including a counterplate facing an end of the shaft distal from the one end on which the hub is mounted, the shaft being supported for rotation within the sleeve by a biased journal bearing comprising fluid in the gap between the shaft and the sleeve, one of the distal end of the shaft or the surface of the counterplate which faces the end face of the shaft having a grooved pattern thereon to maintain fluid in the gap between the shaft and the counterplate, wherein the distal end of the shaft has an outer radial surface at a first radial distance from the center of the shaft and the grooved pattern is disposed within the first radial distance thereby supporting the shaft for rotation relative to the counterplate and sleeve, wherein at least one of the shaft or a center of the counterplate comprises a raised island defining a small touchdown surface for the bottom surface of the shaft, thereby reducing wear on the surfaces of the fluid dynamic bearing defined by the bottom surface of the shaft and the facing surface of the counterplate. |