Abstract: The invention relates to a spindle motor for hard disk drives with improved running accuracy where either 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 rolling bodies. Furthermore, a stator without centering casing is described whose sheet metal package is centered directly on the outer rings/inner raceways.

Abstract: 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.