Abstract: A synchronous machine, in particular a motor for a motor vehicle has an excitation system composed of a plurality of electrically excited individual poles in a stator or a rotor, preferably formed as claw poles excited by at least one joint excitation coil, wherein for compensation of a magnetic stray flux in the intermediate spaces between the mutually oriented and alternatingly nested claw poles, the permanent magnets are inserted on the pole plates on the ends of the stator or rotor, so as to facilitate and simplify the insertion of the permanent magnets required for compensation of the stray flux and to improve their compensation action.

Abstract: A dynamoelectric machine having a permanent magnet rotor construction which contains the permanent magnets while inhibiting flux leakage. The invention further permits rapid, substantially conventional manufacturing techniques to be employed in the formation of rotor laminations used to build the rotors. Flux leakage and formation of reluctance components are inhibited either within the individual rotor laminations or along the length of the rotor by interleaving rotor lamination of different types. The rotor may further be constructed to absorb vibrations within the rotor core and insulate the rotor shaft. The rotor may be still further be constructed for counterbalancing the unbalance of a shaft on which the rotor is mounted.

Abstract: A brushless DC motor for a disc drive having a base and a coil-wound stator secured to an upper portion of the base. One or more first stoppers are secured to the stator and a shaft is rotatably secured in a bearing forcibly inserted in a bore in the upper portion of the base. A hub of a rotor is secured to the shaft and a cylindrical wall extends downwardly at the rim of the hub and carries a magnet facing the stator with an air gap therebetween. A second stopper is secured to the rotor, to face the first stopper to retain the rotor in the axial direction. The second stopper has a flange over which the first stopper is placed with slight clearance. An elastomer rests on the first stopper and carries guides which extend in slots in the rotor to engage and center a hole in a disc.

Abstract: In a stator core, an intermediate portion of a projection and a groove have respectively formed therein: straight portions extending in a certain width in a direction normal to each end surface of yoke portions; and, near the straight portions closer to end surfaces of yoke portions, contracted portions having a width smaller than the width of the straight portions. When the projection is fit by press fitting into the groove in the normal direction, groove walls on both diametrically outer and inner sides of the groove are deflected within an elastic region. When fit by pressing, the straight and contracted portions of the projection are elastically tightened together at the straight and contracted portions of the groove, respectively. An apparatus for assembling a stator core has a plurality of radially disposed and radially movable jigs for holding the segmented cores. Vertically movable cams are provided vertically downwards on an upper vertically movable plate.