Ultra-Thin Spindle Motor Having Groove Formed on the Outer Circumferential Surface of Thrust Bearing

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 its one side 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 bearing 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.