T.h.t. Presses, Inc.

Michael W Thieman

Richard J Kamm

A hermetically sealed disc drive comprising at least one aluminum alloy housing component manufactured with a thermally directed die casting press subassembly is disclosed. In one embodiment, the thermally directed die casting press subassembly comprises a thermally directed funnel gate that is skewed to sample molten material from an off-center portion of the shot sleeve. Disc drive housing components can be manufactured by injecting an aluminum alloy slurry from the shot sleeve through the thermally directed funnel gate and the injection nozzle into the die cavity. The aluminum alloy slurry may be a thixotropic slurry comprising a uniform primary aluminum particle size in the range of approximately 50 to 80 microns. The primary aluminum particles of cast products produced according to the methodology of the present disclosure, with the aforementioned particle size distribution, are free of encapsulated eutectic at the micron scale.

Thermally directed die casting suitable for making hermetically sealed disc drives

A rotor core for an electric motor includes a stack of laminations having peripherally spaced openings receiving copper bars with opposite end portions projecting from the stack. The core is mounted on an arbor and is inserted into a mold on a vertical die cast press having a shot chamber. The mold has upper and lower mold members defining annular cavities receiving end portions of the bars. Molten copper or aluminum is poured into the shot chamber and forced upwardly by a shot piston through passages in the lower mold member and into the cavity around the lower end portions of the bars. The pressurized molten metal solidifies and shrinks around the bar end portions to form an endring for the rotor. The core, endring and arbor are inverted and confined in the mold, and the casting steps are repeated to form the opposite endring.

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Dayton, OH, United States of America

Michael W Thieman