US 5,246,294 A · Flow-regulating hydrodynamic bearing

Abstract

A self-lubricating hydrodynamic spindle bearing for support of a spindle of a magnetic disk drive assembly includes a crankcase design which provides large reservoirs for oil storage with an air cover in communication with the ambient environment through an air vents provided by clearance seals formed between respective central passages of housing-sealing endcaps and the shaft. The crankcase reservoir volume is defined within the bearing so that natural body force effects cause the lubricant to be fed into the hydrodynamic bearing. A leak-preventing capillary trap of minimal continuous axial length may be provided at the clearance seal for passive capture of wandering lubricant when the bearing is at rest. Full evacuation of lubricant trapped at the clearance seal is achieved toward the interior of the housing by centrifugal pumping, e.g., the inboard side of the rotating part of the seal is coned and fluted such that the rotating centrifugal field will throw all statically trapped oil into the lubricant reservoir. A three way restrictive valve is provided to assure balanced feeding of lubricant to both ends of the spindle for either vertical or horizontal spindle orientation. A pressure-actuated bladder may be attached to the bearing to deliver a volume of lubricant to the bearing on demand.

Claims20

Dependent claims

A self-lubricating hydrodynamic spindle bearing comprising:

a stationary stator having a bearing surface;
a rotatably mounted rotor having a bearing surface, the bearing surface of the rotor and the bearing surface of the stator being in sufficiently close spaced apart relationship to form a bearing gap for carrying liquid lubricant, the shape and the position of the rotor and of the stator being effective to form a reservoir for holding liquid lubricant with an outlet to the exterior environment effective to form a clearance seal, the bearing gap being in communication with the reservoir;
and
means for rotating the rotor, the rotation of the rotor generating a centrifugal force that urges the liquid lubricant out of the reservoir and into the bearing gap, the clearance seal effective to retain liquid lubricant therein forming a barrier to the leakage of the liquid lubricant to the external environment when the rotor is idle.

1 more element

Dependencies are inferred from the claim text.

Flow-regulating hydrodynamic bearing

Life of this patent

Flow-regulating hydrodynamic bearing

Life of this patent

Abstract

Claims20