Abstract: An electric machine can include a stator, a rotor frame and a pole arrangement with: plural segment pieces disposed circumferentially around, and fastened to, the rotor frame; permanent magnet pieces positioned on inclined side edges of each segment piece; and plural pole pieces disposed circumferentially around the rotor frame and disposed alternatingly with the segment pieces. The magnet pieces are pressed between inclined side edges of the pole pieces and the inclined side edges of the segment pieces. The segment pieces, the permanent magnet pieces and the pole pieces form a closed ring around the outer surface of the rotor frame, with plural such rings being arranged after each other in an axial direction. An axial air channel can pass through the rings, and at least one radial air duct (R1, R2) between the rings.

Abstract: An electric motor with a permanent magnet excitation comprises permanent magnets retained in a pole housing and associated with the flux-conducting element, wherein at least one permanent magnet and a flux-conducting element are arranged so that they are in positively interlocking engagement.

Abstract: A fuel pump may include a motor section comprising a rotor and a stator. One of the rotor and the stator may have at least a pair of permanent magnet parts disposed along a first circumferential surface at an interval in a circumferential direction, and at least two magnetic material parts disposed between ends of adjacent permanent magnet parts. The other one of the rotor and the stator may have a first yoke disposed so as to face the permanent magnet parts, wherein a plurality of slots are formed on the first yoke at an interval in the circumferential direction. A surface facing the slots of the magnetic material parts may be shifted, in at least a partial range in the circumferential direction including a permanent magnet part side end where a polarity of a first circumferential surface side is a north pole, from the first circumferential surface in a direction along which a distance to the slots increases.

Abstract: Engaging protrusions of a lower end housing are axially snap-fitted into through holes, respectively, of a yoke housing to couple therebetween. Each of spacers is circumferentially placed between and is press-fitted between corresponding adjacent two of permanent magnets fixed to an inner peripheral surface of the yoke housing. Each spacer axially contacts a corresponding contact part of the end housing. A lower ball bearing and an upper ball bearing are supported by the lower end housing and an upper end housing, respectively, to rotatably support a shaft. A wave washer is axially positioned between the lower ball bearing and the lower end housing to exert an urging force between the lower end housing and the upper end housing through the shaft.

Abstract: When the magnet holding spring is in the deployed state of the plate-like shape, the auxiliary pole is beforehand fixed to one of the side-plates, then the magnet holding spring is bent into a “]”-like sectional shape. As a result, the magnet holding spring and the auxiliary pole that are assembled integrally constitute the sub-assy. Convex parts are formed on the auxiliary pole. The auxiliary pole is fixed to one of the side-plates by press fitting the convex parts to the fitting holes formed on one of the side-plates. The auxiliary pole is laid on one of the side-plates in the direction of a plate thickness for positioning before forming the convex parts on the auxiliary pole. In the positioned state here, by embossing the auxiliary pole, the convex parts are formed on the auxiliary pole, and at the same time, the convex parts are press fit into the fitting holes thus the auxiliary pole is fixed to one of the side-plates.