Abstract: An ac generator comprising a rotor coil for generating a magnetic flux, a pole core disposed to cover the rotor coil and having pawl-shaped magnetic poles projecting in staggered and alternating relationship, permanent magnets disposed on both side surfaces of the pawl-shaped magnetic poles for reducing the leakage of the magnetic flux, and a fan for cooling. The permanent magnets are samarium-iron alloy magnets containing Ti and B, or plastic magnets made of magnet powder bonded together by a resin, bonded magnets of Sm8.2—Fe75.6—Ti2.3—B0.9—N13. One portion of the side opposing to the pawl-shaped magnetic pole side surfaces of the permanent magnet may be resin-coated. A restricting means for restricting the displacement of the magnetic pole in the radial direction may be disposed in the vicinity of the tips of the magnetic poles.

Abstract: For achieving a constant capacity range by way of field weakening of a permanent magnet excited drive the magnetic transverse resistance (Rm) of the rotor plate pack is increased by pole gaps (P1, P2), which are produced by milling into the upper surface (O) of the rotor plate section (L), or are punched into the rotor plate section (L), whereby a covering of the poles of Tp in the range of from 70% to 80% has been shown to be particularly advantageous.

Abstract: A rotor structure for an electric motor includes a cylindrical rotor core assembly and a plurality of permanent magnets disposed on an outer circumference of the rotor core assembly. Wrapped around the rotor core assembly is a bandage to secure the permanent magnets in place, wherein the bandage has a bandage edge arranged in proximity of an end surface of the rotor core assembly. In order to securely fix the bandage edge in place, a securing ring is disposed radially over the bandage edge of the bandage to hold the bandage against the rotor core assembly.

Abstract: The vehicle alternator comprises a rotor having interleaved pole pieces, permanent magnets disposed between the pole pieces, and at least one magnet-support strip which extends over a circumferential outside face of the pole pieces.

Abstract: A spindle motor rotor having windows at plural places in a flange of a rotor yoke of a spindle motor, as well as projections protruding outwards through the windows, integrally provided in some areas of a ring rotor magnet fitted to the inner circumference of the flange, wherein the rotor magnet is joined to the rotor yoke by welding these projections and one of the projections stretches over both an N pole and an S pole of the rotor magnet.