Precision Motors Deutsche Minebea Gmbh

J&ouml;rg Hoffmann

Thilo Rehm

The invention related to a spindle motor for hard disk drives with improved running accuracy where the sheet metal package or the complete stator consisting of sheet metal package and windings is encompassed by a centering casing of plastic, which is preferably applied by means of an injection molding operation. Depending on the design of the spindle motor the centering casing can be centered on the stationary shaft and/or on the outer rings/inner raceways pertaining to the sets of roolling bodies. Furthermore, a stator without centering casing is described whose sheet metal package is centered directly on the outer rings/inner raceways.

Spindle motor for hard disk drives with improved running accuracy

The invention relates to a spindle motor having a sealing support film which prevents exchange of air between the interior and surroundings of the spindle motor. In spindle motors for hard disk drives it is extremely important to construct the spindle motor so that it is sealed tight against the external environment, ie so that from the connecting side of the spindle motor no admission of air to the interior of the spindle motor can occur. A further characteristic of the invention consists in that the support film is bonded and fixed in place in sealing manner by means of an adhesive which does not give off gas or does so only very slightly.

Spindle motor with sealing, flexible support film

A spindle-drive motor for hard drives having a baseplate, a shaft and one or more bearings for rotational mounting of a rotationally driven rotor, with at least one magnetic fluid seal arranged between the stationary part and the rotating part of the spindle-drive motor. The seal is formed of an upper and a lower yoke lamination and a magnet disk arranged between the yoke laminations, where a concentric chamber is formed so that it is open toward the inside on one side to hold a magnetically conducting fluid. A flux concentrating lamination extends into this chamber. In one embodiment of this invention, the flux concentrating lamination is in direct or indirect contact with one end face of the inner bearing ring of the bearing, while the outer part of the magnetic fluid seal is in direct or indirect contact with the end face of the outer bearing ring of the bearing. In another embodiment, the flux concentrating lamination on the inside is in direct or indirect contact with a radial reference shoulder of the shaft.

Growing community of inventors

Mettlach, Germany

Jörg Hoffmann

Growing community of inventors

Mettlach, Germany

J&ouml;rg Hoffmann

Jörg Hoffmann