Abstract: A device to press a rotatably supported shaft of a rotor of a spindle motor for a hard disk drive into a shaft receiving portion of an associated stator housing by means of a first pressing tool acting on the rotor and a second pressing tool acting on the stator housing. A first aligning apparatus for the rotor and a second aligning apparatus for the stator housing are provided. The first and second aligning apparatuses are formed in such a way that they guide the rotor by means of a rotor carrier and the stator housing by means of a stator carrier. The rotor carrier and the stator carrier are exactly aligned with respect to each other during the pressfitting process. The first pressing tool has a first pressing element acting on the shaft of the rotor that is independent of the first aligning apparatus and the second pressing tool has a second pressing element acting on the stator housing that is independent of the second aligning apparatus.

Abstract: In order to improve a device to press a rotatably supported shaft of a rotor of a spindle motor for a hard disk drive into a shaft receiving portion of an associated stator housing by means of a first pressing tool acting on the rotor and a second pressing tool acting on the stator housing, inasmuch as high manufacturing precision, with low process tolerances in particular, can be achieved, it is proposed that a first aligning apparatus for the rotor and a second aligning apparatus for the stator housing are provided, that the first and second aligning apparatuses are formed in such a way that they guide the rotor by means of a rotor carrier and the stator housing by means of a stator carrier exactly aligned with respect to each other during the pressfitting process, and that the first pressing tool has a first pressing element acting on the shaft of the rotor that is independent of the first aligning apparatus and the second pressing tool has a second pressing element acting on the stator housing that is ind

Abstract: The invention concerns a spindle motor, comprising a stationary base flange that supports a central spindle, a hub that is positioned pivoting on the spindle with the aid of suitable bearings and on which at least on fixed-memory disc is arranged, wherein the hub has a rotor magnet on the inside circumference, and comprising a stator-side winding packet, which is arranged at the base flange and is positioned opposite the rotor magnet, wherein the winding packet is extrusion-coated completely with an elastic mass and is thereby connected to the base flange.

Abstract: In a method and apparatus for determining the rotary angular position of a rotary member when measuring unbalance on the rotary member, during an unbalance measuring run the rotary member is twice sensed in the peripheral direction in a given succession in respect of time, resulting in the formation of first and second angle signals which are displaced in respect of time. The two signals are stored, having regard to their spacing in respect of time. The two signals are evaluated for rotating the rotary member, in dependence on the measured angular position of an unbalance, into a balancing position for carrying out a balancing operation on the rotary member.

Abstract: An apparatus for unbalance measurement on a rotary member comprising a rotary mounting device for the rotary member and an oscillatable support for the rotary mounting device for supporting same on the foundation of the apparatus. A force and/or oscillation measuring equipment is operatively disposed between the foundation and the rotary mounting device for measuring centrifugal forces and/or oscillations which result from unbalance of the rotary member. To determine the mass of the rotary member in the rotary mounting device, the apparatus measures the force due to the weight of the rotary member, disposed in the path of transmission of force between the rotary mounting device and the foundation.

Abstract: A mechanical drive arrangement for a measuring spindle of a wheel balancing machine has an actuator in the form of a lever which is actuable by hand for producing a torque which is transmitted to the measuring spindle for driving same.

Abstract: Apparatus for gripping a workpiece such as a rotor is provided which includes gripper arms, a pressure-sensitive sensing member on one of the arms for continuously measuring the gripping force applied by the arms, and a piezoelectric actuator on the outer arm which is actuated to provide fine adjustment of the gripping force in dependence on the output of the sensing member.

Abstract: A measuring apparatus in which a rotary member is mounted and rotated for measurement or testing thereof, with measuring devices including measurement value pick-up structures for periodically detecting varying forces and/or moments caused by the rotating rotary member. The measuring apparatus includes a machine bed which serves as a component for carrying the measuring devices and for mounting the rotary member. The machine bed is in the form of a casting comprising polymer concrete.