Seagate Technology Incorporated

Alireza Rahimi

Kamran Oveyssi

Long Van Nguyen

Robert Alan Nottingham

Donald J MacLeod

A spindle for a disc drive which can be assembled without the use of adhesives is disclosed. Stator electromagnets are encapsulated in a plastic overmold. The stator is clamped to the base with a clamp spring arrangement. An offset between the stator surface and the base flange is covered by a clamp spring such that binding of the clamp spring by a fastener allows for an adjustable biasing force to secure the stator in place. The magnet and flux shield are attached to the rotor sleeve by an easily positioned retaining ring. An elastic foam washer provides a controlled force to secure the magnet and flux shield in place on the rotor. A second elastic foam washer and a shield provide a controlled biasing force to hold magnetic fluid and magnetic poles to the rotor. Bearings are laser welded to the rotor and the shaft to rotatably mount the rotor about the shaft.

Adhesiveless disc drive spindle assembly

A head-arm assembly having a pair of trapezoidal-like shaped coil bobbins for improved torque and moments of inertia in a voice coil motor (VCM) for a disk drive. The VCM includes a magnetic structure that employs three magnet polarity zones having two flux transition zones. The magnetic structure is able to employ relatively thin pole pieces without saturation or leakage. The thin pole pieces permit use of a thicker magnet in the same envelope size. The result is an increased flux density in the air gap of the VCM, giving higher torque and shorter access time. In addition to improving the torque and moments of inertia, the present invention allows use of thicker magnets (thinner pole pieces) and allows the option of using a thinner coil that is wider radially. In another version, an oval-shaped coil may be used for increased effective length when disposed within a magnetic field of a VCM.

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Los Altos, CA, United States of America

Alireza Rahimi