Fluid dynamic bearing system and a spindle motor having this kind of bearing system

Abstract

The invention relates to a fluid dynamic bearing system having a bearing bush and a shaft that are rotatable with respect to one another about a common rotational axis and form a bearing gap filled with bearing fluid between associated bearing surfaces. The bearing surfaces form at least one fluid dynamic radial bearing. A rotor component is disposed on the shaft. A stopper ring is disposed on the shaft or on the rotor component and adjoins the bearing bush, wherein a gap is formed between the mutually facing surfaces of the bearing bush and the stopper component that is filled with a bearing fluid and connected to the bearing gap and extends substantially in a radial direction. According to the invention, the surfaces of the bearing bush and/or the stopper component are formed such that the gap is tapered, narrowing radially outwards. Moreover, a recirculation channel may be provided in the bearing bush that connects a gap region between the bearing gap and the sealing gap radially outside the axial bearing to a gap region radially outside the stopper component.