Patent ID: 7153028

Claim:
A hydrodynamic bearing system for the rotary bearing of spindle motors to drive platters in hard disk drives which comprises: at least one inner bearing part ( 10 ; 23 ; 41 ; 54 ); at least one outer bearing part ( 12 , 13 , 13 ′; 25 , 26 ; 43 , 44 ; 56 ), the bearing parts being rotatable about a rotational axis ( 22 ) with respect to one another, at least one radial bearing region and/or at least one axial bearing region which are formed on surfaces of the bearing parts facing each other; a bearing gap ( 16 ; 29 ; 48 ; 59 ) filled with a lubricant formed between surfaces of the bearing parts facing each other, and a fluid-conducting equalizing volume connected to the bearing gap for the lubricant, a single or multiple thread is formed on the circumference of the outer bearing part ( 12 , 13 , 13 ′; 25 , 26 ; 43 , 44 ; 56 ), the outer bearing part being enclosed by a sleeve ( 14 ; 14 ′; 27 ; 45 ; 57 ) so that an equalizing volume taking the form of a winding channel ( 18 ; 18 ′, 31 ; 50 ; 60 ) is formed between the outer bearing part and the sleeve; and a reflow channel ( 17 ; 30 ; 49 ) extending in an axial direction is arranged within the sleeve and/or outer bearing part ( 12 , 13 , 13 ′; 25 , 26 ; 43 , 44 ; 56 ) which connects a section of the bearing gap ( 16 ; 29 ; 48 ; 59 ) associated with the radial bearing region to a section of the bearing gap associated with the axial bearing region.