Seagate Technology Incorporated

Gregor Flores

Klaus Dieter Kloeppel

Norbert Steven Parsoneault

Troy Michael Herndon

Robert Alan Nottingham

Jeffry Arnold LeBlanc

Anthony Joseph Ajello

According to various embodiments of the invention, a motor with a rotatable hub having fluid dynamic journal and thrust bearings can be assembled from four major components: a spindle, a hub, a thrust washer, and a base. The spindle can integrate journal bearing, axial limiter, and ring seal functions. The hub can integrate journal bearing, thrust bearing, ring seal, axial limiter, capillary seal, and bumper functions. The thrust washer can integrate thrust bearing and lubricant circulation functions. The base can integrate capillary seal and lubricant storage and circulation functions. Each function can be integrated as structural feature in its corresponding component. The spindle, hub, and thrust bearing can be preassembled. The base can be loaded with lubricant prior to assembly with the spindle/hub/thrust bearing combination.

Spindle regions

The design comprises a shaft and sleeve supported for relative rotation by a journal type fluid dynamic bearing utilizing grooves on one of the shaft or sleeve surfaces. A grooved pattern of a design similar to that usually found on a thrust plate is defined on an axial end surface of the shaft or the counterplate facing the axial end of the shaft, so that thrust is created to maintain separation of the end of the shaft and the facing thrust plate during relative rotation. In one embodiment, to establish and maintain the gap between the shaft end and the facing counterplate, the journal bearing has an asymmetry to pump toward the shaft end having the bearing. In a further refinement, to maintain the shaft and gap within an optimum spacing, a magnet is mounted to provide an axially directed magnetic force on the shaft which works against the axial force created by shaft end thrust bearing. To prevent separation of the shaft and sleeve or hub, the hub which is integrated with a rotating shaft, further incorporates a shoulder which extends axially beneath a cooperating shoulder on the sleeve surrounding the shaft to prevent any more than a limited axially displacement of the hub and shaft relative to the sleeve.

Low profile fluid dynamic bearing

A method for detecting air-contamination within a hydrodynamic bearing used with a disc drive comprises in one embodiment, a method to detect air-contamination with hydrodynamic fluid by measuring operating signals of the disc drive between different external air pressure conditions (including ambient) on the hydrodynamic bearing and comparing the operating signals to predetermined threshold values. In another aspect, the invention provides an air-contamination detecting apparatus adapted to detect air-contamination within the fluid of a hydrodynamic bearing. In another aspect, the invention provides a method to determine air-contamination within hydrodynamic bearings using the change in disc drive input/output signals responsive to air-pressure changes on the hydrodynamic bearings.

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Felton, CA, United States of America

Gregor Flores