Motor having single cone fluid dynamic bearing balanced with shaft end magnetic attraction
AssigneeKura Laboratories Corporation
InventorYoshikazu Ichiyama
Life of this patent
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Abstract
A single cone fluid dynamic bearing motor, including a shaft having a diminishing conical taper surface, a sleeve having a concavity opposite the shaft, lubricant filled in a clearance between the shaft and the sleeve, and magnetic members to generate magnetic attraction between one end of the shaft and a cone apex of the sleeve. Grooves are formed on the conical taper surface of the shaft or the sleeve so as to create load capacity when the motor rotates, whereby rotating parts of the motor are supported by the axial components of the load capacity balanced with the magnetic attraction. The motor thereby achieves reduction in thickness, current, and cost, and inhibits non-repeatable runout.
Claims11
A fluid dynamic bearing motor, comprising:
- a shaft having a diminishing conical taper surface;
- a sleeve having a conical concavity opposite the shaft;
- lubricant filled in a clearance between the shaft and the sleeve;
- and
- means for generating magnetic attraction between one end of the shaft and a cone apex of the sleeve, including a magnet and a magnetic material, the magnet being provided in one of the shaft and the sleeve and the magnetic being provided in the other one thereof;
- and
- an annular wall arranged around the shaft to face an outer circumferential wall of the sleeve, a clearance between the annular wall and the outer circumferential wall of the sleeve being increased in width toward an open end to form a taper seal of the lubricant;
- wherein
- a plurality of grooves are formed on at least a conical taper surface of one of the shaft and the sleeve, the grooves being provided for creating load capacity when the motor rotates, whereby rotating parts of the motor are supported by axial components of the load capacity balanced with said magnetic attraction.
Dependencies are inferred from the claim text.