Abstract: An electrical commutator machine which serves to actuate units is proposed. The commutator machine comprises a ring-like carrying plate, which surrounds the axis of rotation of the commutator, for tubular guide casings which are made of metal, have a square cross section, are permanently connected to said carrying plate and in which brushes belonging to the commutation device are guided along the longitudinal axis of the tube and are placed under load on a contact face of the commutator. A particularly simple and advantageous structure of the commutator machine is produced if, in order to secure the casing on the carrying plate, at least two tongues which are upright with respect to the wall plane are arranged on one of the casing walls, to which tongues there are assigned insertion slits which are located in the one end of the carrying plate and detain the tongues.

Abstract: In a permanent-magnet-excited commutator motor, especially a small motor for motor vehicles, the short-circuit ring (13) of the stator (12) has soft iron auxiliary poles (16), to attain an inverse speed characteristic. The permanent magnets (15) rest with their arc-shaped outer face on the short-circuit ring (13) and are laterally supported on one side by a side flank of the auxiliary poles (16) and on the other side by a supporting element retained on the short-circuit ring (13). To enable securing the permanent magnets in a manner suitable for large-scale mass production, the supporting elements are embodied as protrusions (19) bulging radially in the inward direction and integral with the short-circuit ring (13). Assembly is accomplished by simple insertion of the permanent magnets (15) between the auxiliary poles (16) and the associated protrusions (19).

Abstract: A permanent-magnet excited commutator motor, particularly a multipole small motor, has a stator yoke, an armature, two permanent magnet elements having a relatively low permeability, the permanent magnet elements having end tips with a gap formed between, the permanent magnet elements having one tip located forwardly as considered in the rotary direction of the armature, and a ferromagnetic auxiliary pole arranged on the stator yoke and having a relatively high permeability, the auxiliary pole being a U-shaped bracket having legs abutting against the end faces of the low permeability magnet elements, the bracket which forms the auxiliary pole being elastic and asymmetrical and formed as a holding spring, and legs of the bracket including a thicker leg and a thinner leg, where the thicker leg is formed as a stray web abutting against the permanent magnet tip lying forwardly in the rotary direction of the armature.

Abstract: Two-component, permanent field magnets are located opposite the armature and protrude beyond the armature core at both axial ends. The flux yield of the field magnets is improved in comparison with conventional two-component magnets by positioning a section (14) of highly coercive magnetic material (2) at the trailing edge, with an axial length only of substantially the axial length (1.sub.A) of hte armature core, and placing protruding portions (16), protruding axially beyond (1.sub.M) the armature core (10) of a highly remanent magnetic material (1).

Abstract: A permanent magnet stator having two arcuate permanent magnet segments, each composed of two subsegments.

Abstract: An electric machine includes a flux-return yoke, a plurality of segmental permanent-magnet stator magnets mounted in the yoke with their outer peripheral surfaces engaging the inner peripheral surface of the flux-return yoke, and a wound rotor mounted for rotation in the space defined by the segmental stator magnets. Either the segmental stator magnets on their outer peripheral surfaces or else the flux-return yoke on its inner peripheral surface is provided with a structured surface portion adapted to properly position the stator magnets relative to the yoke. The structured surface portion has the form of a multitude of projections of identical height arranged in rows to form an array.

Abstract: The spark plug center electrode is a composite of a jacket of corrosion resistant material, central filamentary core electrode elements, likewise of corrosion resistant material, and a matrix of thermally and electrically highly conductive material in which the corrosion resistant filamentary elements are embedded, filling the electrode within the outer jacket; in accordance with the present invention, the matrix material is recessed with respect to the jacket and the sparking ends of the corrosion resistant filamentary material to increase lifetime and to provide protection for the electrically and thermally highly conductive material and ensure ignition of even comparatively lean fuel-air mixtures. The electrode has an overall diameter in the order of about 2.4 mm, the recess of the matrix material being between 50 to 500 .mu. m, preferably about 100 to 250 .mu. m; a platinum coating having a thickness of preferably between 40 and 50 .mu. m can be provided to cover the exposed end of the electrode.