Abstract: In a rotating machine, for example heteropolar, auxiliary poles (14) are placed in practically the field poles (4) and close to the peripheral of a salient section (.delta.) of rotor (2), the same azimuth symmetry plane as the poles are supplied by a current (i) regulated by a power supply and auxiliary regulation device (16), the armature current (I) and rotation speed (N) of the rotor expose armature conductors (8) in commutation to an equalizing flux providing for arc-free commutation. Auxiliary poles can be supplied with a current regulated by the field current to cancel the currents flowing in the armature conductors on the field poles. These machines, for example also acyclic with voltage step-up, have high specific power and efficiency, and can be employed for example, in electric traction or propulsion.

Abstract: In a homopolar dynamoelectric machine in which a magnetic flux moves across a generally cylindrical clearance space between the stator and rotor, counterproductive magnetic fields produced by axial electric currents are avoided by providing, on the mutually confronting surfaces of the stator and rotor, nonmagnetic electrical conductors which are electrically insulated from the magnetic portions of the stator and rotor. The conductors are connected together electrically by contacts, providing an electrically conductive loop which encloses no magnetic members. Leads from the electrically conductive loop may be connected to an external circuit.The electrical conductors in one embodiment are of solid cylindrical shape, and in other embodiments are formed of spaced bars as in a squirrel cage. When spaced bars are used, the bars on one member are axially oriented and the bars on the other member are arranged in two sets which are equally but oppositely inclined to the machine axis.

Abstract: Sliding electrical contact devices comprising a conducting track and a brush bearing on the track. The brush is formed by at least one bundle of stiff and very fine wires whose diameter is of about 40 microns, tightly retained in a sole piece 14, projecting from the sole piece and slidingly bearing on the track.