US 6,981,797 B2
Hydrodynamic bearing unit
Natsuhiko Mori, Kuwana (Japan); Yoshinobu Akamatsu, Kuwana (Japan); and Kazuo Okamura, Kuwana (Japan)
Assigned to NTN Corporation, Osaka (Japan)
Filed on Jan. 09, 2004, as Appl. No. 10/753,448.
Application 10/753448 is a continuation of application No. 09/925830, filed on Sep. 09, 2001, granted, now 6,712,514.
Claims priority of application No. 2000-252423 (JP), filed on Aug. 23, 2000; application No. 2000-252945 (JP), filed on Aug. 23, 2000; and application No. 2001-155930 (JP), filed on May 24, 2001.
Prior Publication US 2004/0247212 A1, Dec. 09, 2004
This patent is subject to a terminal disclaimer.
Int. Cl. F16C 32/06 (2006.01)
U.S. Cl. 384—107 3 Claims
OG exemplary drawing
 
1. A hydrodynamic bearing unit comprising a shaft member having a shaft portion and a flange portion, a bearing member arranged on an outer circumference of the shaft member; and a radial bearing portion and a thrust bearing portion respectively comprising bearing surfaces with grooves for generating hydrodynamic pressure and bearing clearances facing the bearing surfaces, and supporting the shaft member in non-contact state, in the radial direction and the thrust direction respectively, with hydrodynamic pressure generated in the bearing clearances when the shaft member and the bearing member relatively rotate;
wherein the squareness of the both end surfaces of the flange portion with respect to the outer circumference of the shaft portion of the shaft member is 0.001 mm or less respectively, and the flatness of both end surfaces of the flange portion is 0.001 mm or less respectively.