Distortion free laser welded fluid bearing design
AssigneeSeagate Technology LLC
InventorsLynn Bich-Quy Le, Donald J. Macleod, Anthony J. Aiello
Life of this patent
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Abstract
The counterplate and/or sleeve are modified to reduce or eliminate distortion in the counterplate in a laser welded fluid bearing design. It is known to directly weld the counterplate which lies across the end of the shaft and the thrust plate to a wall or shoulder of the sleeve in which the counterplate is fit. The radial stiffness of the sleeve is weakened by cutting grooves or the like at or near the interface between the sleeve wall and the counterplate, or on the outer diameter of the sleeve wall to essentially weaken the sleeve wall. This weakening of the sleeve wall prevents bowing or distortion of the counterplate being imposed by the sleeve.
Claims20
A spindle motor for use in a disk drive comprising a shaft supporting a thrust plate at one end thereof, a sleeve surrounding the shaft, and rotatable relative to the shaft and supporting a hub on the outer surface thereof, the sleeve having a surface adjacent the thrust plate and cooperating with the shaft to define a journal bearing and with the thrust plate to define a first fluid dynamic thrust bearing, a counterplate welded to an upraised axial shoulder of the sleeve and having a surface located adjacent a surface of the thrust plate to define at least a second fluid dynamic thrust bearing, fluid within the first and second thrust bearings and the journal bearing supporting relative rotation of shaft and sleeve, and a groove region defined in the shoulder of the sleeve radially aligned with adjacent the counterplate.
A fluid dynamic bearing comprising a shaft supporting a thrust plate at one end thereof, a sleeve surrounding the shaft, and rotatable relative to the shaft and supporting a hub on the outer surface thereof, the sleeve having a surface adjacent the thrust plate and cooperating with the shaft to define a journal bearing and with the thrust plate to define a first fluid dynamic thrust bearing, a counterplate welded to an upraised axial wall of the sleeve and having a surface located adjacent a surface of the thrust plate to define at least a second fluid dynamic thrust bearing, fluid within the first and second thrust bearings and the journal bearing supporting relative rotation of the shaft and sleeve, and a groove defined in the arm of the sleeve radially adjacent the counterplate.
A fluid dynamic bearing comprising a shaft supporting a thrust plate at one end thereof, a sleeve surrounding the shaft, and rotatable relative to the shaft and supporting a hub on the outer surface thereof, the sleeve having a surface adjacent the thrust plate and cooperating with the shaft to define a journal bearing and with the thrust plate to define a first fluid dynamic thrust bearing, a counterplate welded to an upraised axial shoulder of the sleeve and having a surface located adjacent a surface of the thrust plate to define at least a second fluid dynamic thrust bearing, fluid within the first and second thrust bearings and the journal bearing supporting relative rotation of shaft and sleeve, and means defined in the upraised wall for weakening the radial stiffness of the wall.
Dependencies are inferred from the claim text.