Patent ID: 7586223
Filing Date: 2009-09-08
Classification: F16C

Abstract:
1. An ultra-thin spindle motor having a groove formed on the outer circumferential surface of a thrust bearing which uses a hydro dynamic bearing, comprising: a hub ( 10 ) of a cap shape opened downwardly to mount a plurality of platters thereon, wherein a magnet ( 20 ) is installed in the inner side or outer side of vertical wall surface of the hub and a coupling portion ( 12 ) is formed on the center portion of the hub to couple a thrust bearing sleeve ( 50 ) to the center portion; the thrust bearing sleeve ( 50 ) being coupled to the coupling portion ( 12 ) of the hub ( 10 ) for coupling the hub ( 10 ) and a thrust bearing ( 40 ) wherein the thrust bearing sleeve ( 50 ) is of a cylindrical shape having a closed surface at one side thereof and has a first inner circumferential hole ( 52 ) to which a cover plate ( 90 ) is coupled from the opened side and a second inner circumferential hole ( 54 ) extended from the first inner circumferential hole ( 52 ) and having the thrust bearing ( 40 ) insert-mounted thereon; the cover plate ( 90 ) coupled to the first inner circumferential hole ( 52 ) of the thrust bearing sleeve ( 50 ) for shielding the thrust bearing sleeve ( 50 ) having the thrust bearing ( 40 ) mounted thereon and thus restricting the thrust bearing ( 40 ) in a vertical direction; a first through hole ( 100 ) formed on the closed surface ( 56 ) of the thrust bearing sleeve ( 50 ) or the center portion of the cover plate ( 90 ) in order to couple the shaft ( 30 ) coupled to the thrust bearing ( 40 ) to a base ( 60 ); the thrust beating ( 40 ) being of a disc shape having a given thickness, being inserted into the second inner circumferential hole ( 54 ) of the thrust bearing sleeve ( 50 ) and having a shaft coupling hole ( 42 ) for coupling the shaft ( 30 ) formed on the center portion thereof, a radial hydro dynamic pressure generating groove ( 82 ) formed on the outer circumferential surface of the thrust bearing ( 40 ); an axial dynamic pressure generating groove ( 84 ) formed on the upper and lower surfaces of the thrust bearing ( 40 ) or the closed surface ( 56 ) of the thrust bearing sleeve ( 50 ) and an one surface of the cover plate ( 90 ); the shaft ( 30 ) being insert-fixed into the shaft coupling hole of the thrust bearing ( 40 ) and fixedly coupled vertically to the base ( 60 ) with contactlessly penetrating the first through hole ( 100 ); the base ( 60 ) couple vertically to the shaft ( 30 ) for fixedly supporting the shaft ( 30 ); and a stator core ( 70 ) having coil wound thereto and coupling the base ( 60 ) to face the magnet ( 20 ).