Patent attributes
The invention relates to a fluid dynamic bearing system particularly for the purpose of rotatably supporting a spindle motor, having a first bearing part that comprises a bearing sleeve, and a second bearing part that comprises a shaft, the two bearing parts being spaced apart from one another by a bearing gap and being rotatable with respect to each other, wherein the bearing sleeve is closed at one end by a counter plate that is accommodated in an annular recess in the bearing sleeve and connected to the bearing sleeve by a welded joint. According to the invention, a bearing system is provided in which the counter plate has a reduced thickness (D2) at its outer edge and is welded in the region of its reduced thickness (D2) to the bearing sleeve. The reduced thickness of the counter plate at the region of its outer edge means that the vertical gap between the bearing sleeve and the counter plate is made very much shorter, or is done away with altogether, so that no unwanted air can remain in the gap.