Patent ID: 6059459
Filing Date: 2000-05-09
Classification: F16C,G11B

Abstract:
A hydrodynamic bearing comprising:a shaft;a sleeve member for receiving said shaft, said shaft and said sleeve member defining a gap therebetween;said gap having upper and lower open ends and hydrodynamic fluid filled within said gap;at least one set of asymmetric grooves on one of said shaft and said sleeve member aligned to pump said hydrodynamic fluid along said shaft;a thrust plate coupled to said shaft in the vicinity of an upper open end thereof, said thrust plate having an upper and a lower surface having asymmetric grooves thereon to pump said hydrodynamic fluid toward an outer circumferential portion of said thrust plate and away from said shaft, said thrust plate further having a plurality of communicating holes traversing said thrust plate to open at said upper and lower surfaces, an upper opening of said communicating holes connecting with external atmosphere;said sleeve member being provided with an annular groove disposed in the vicinity of a lower opening of said communicating holes such that air which enters into said gap through said communicating holes by atmospheric pressure is retained by said annular groove and said hydrodynamic fluid filled within said gap is controlled and balanced by said air so as to contain said hydrodynamic fluid in the bearings; andsaid thrust plate also including a plurality of through holes extending radially from said communicating holes to said outer circumferential portion of said thrust plate such that said hydrodynamic fluid is pumped toward said outer circumferential portion and away from said shaft and circulates to said upper and lower surface of said thrust plate through said through holes and said communicating holes.