The invention relates to a hydrodynamic bearing system particularly for the rotary bearing of spindle motors to drive the platters in hard disk drives which comprises at least one inner bearing part and at least one outer bearing part, the bearing parts being rotatable about a rotational axis with respect to one another. The bearing system has 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 filled with lubricant is formed between the surfaces of the bearing parts facing each other and is connected to an equalizing volume in a fluid-conducting way.According to the invention, the equalizing volume is formed from a single or multiple thread provided on the circumference of the outer bearing part. The outer bearing part is enclosed by a sleeve so that a winding channel acting as an equalizing volume is formed between the outer bearing part and the sleeve.