Patent ID: 7309937

Claim:
A spindle motor of a small-scale design having a hydrodynamic bearing system which comprises: a rotor ( 6 ) having a rotor hub ( 7 ) and a shaft ( 8 ) connected to the rotor hub; a cylindrical bearing sleeve ( 10 ) having a central bore to receive the shaft ( 8 ) and a collar ( 11 ) disposed at a receiving aperture; a baseplate ( 13 ) to hold a bearing receiving portion; a stopper ring ( 14 ) disposed at the inside circumference of the rotor hub ( 7 ) between the collar ( 11 ) and the baseplate ( 13 ); and at least one radial bearing region ( 15 , 16 ) formed between the outside diameter of the shaft and the inside diameter of the bore and defined by surface patterns ( 19 ), characterized by a cup-shaped bearing housing ( 12 ) closed at one end to accommodate the bearing sleeve ( 10 ); an annular axial bearing region ( 18 ) formed between a lower face of the collar ( 11 ) and an upper face of the stopper ring ( 14 ), and further characterized in that between the regions facing each other of the bearing housing ( 12 ) and the bearing sleeve ( 10 ), at least one fluid channel ( 24 ) is provided which connects a section ( 17 ) of the bearing gap between the bearing sleeve ( 10 ) and the shaft ( 8 ) to the end of a section ( 20 ), adjacent to the sealing region ( 23 ), of the bearing gap between the collar ( 11 ) and the stopper ring ( 14 ).