Hydrodynamic bearing for a spindle motor
AssigneeMinebea Co., Ltd.
InventorOlaf Winterhalter
Life of this patent
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Abstract
A hydrodynamic bearing for use in a spindle motor, having a shaft, a bearing sleeve encompassing the shaft with a small radial space, and a skewback at one end face of the bearing sleeve which is fixedly connected to the bearing sleeve. The shaft features a thrust plate or a conical or cone-like extension at its end face which faces the skewback. The diameter of the conical extension increases in the direction of the end face of the shaft. A bearing gap formed between the shaft and the bearing sleeve is filled with a bearing fluid. Dynamic pressure generating grooves are provided on one of the outer surface of the shaft and the inner surface of the bearing sleeve to generate an excess pressure in the bearing fluid.
Claims20
A spindle motor for use in hard disk drives comprising:
- a shaft, said shaft comprising a gradually expanding lower portion;
- a bearing sleeve surrounding said shaft such that a bearing gap is formed between said shaft and said bearing sleeve;
- and
- a plurality of pressure generated grooves being formed on one of an outer surface of said shaft and an inner surface of said bearing sleeve, wherein said gradually expanding lower portion expands toward an end face of said shaft, and wherein said gradually expanding lower portion of said shaft is provided with at least one fluid channel, said fluid channel comprising a large diameter.
A hydrodynamic bearing for use in a spindle motor, comprising:
- a shaft;
- a bearing sleeve, the bearing sleeve rotatably surrounding said shaft;
- a counter-plate enclosing one end face of said bearing sleeve;
- a bearing gap formed between the shaft, the bearing sleeve and the counter-plate, said bearing gap being filled with a bearing fluid;
- and
- means for generating an excess pressure in the bearing fluid in the area of the counter-plate, the excess pressure being greater than the atmospheric pressure.
Dependencies are inferred from the claim text.