Patent ID: 6702464
Filing Date: 2004-03-09
Classification: F16C,G02B,G11B,H02K

Abstract:
A hydrodynamic bearing assembly, comprising:a column shaft having an outer surface and a top and bottom surfaces, said shaft extending in a longitudinal direction; a thrust plate secured on the bottom surface of said shaft so as to extend in a perpendicular direction to the longitudinal direction, said thrust plate having a circumference end and an upper and lower surfaces; a cylindrical hollow sleeve arranged around said shaft with a predetermined radial gap, said sleeve having an inner surface and a thrust opposing surface opposing to said thrust plate; a plurality of grooves formed on a surface selected from a group consisting of the outer surface of said shaft and the inner surface of said sleeve, for preventing a half-whirl, each of said grooves defining an upstream and downstream sides along a direction of a relative rotation; wherein upon the relative rotation of said sleeve and said shaft, a thrust gap is formed in fluid communication with the radial gap and between the thrust opposing surface of said sleeve and the upper surface of said thrust plate, and each of said grooves varying its depth for reducing the dynamic pressure generated adjacent to the downstream side of the groove.