GB1323484A - Electric machine of disc construction - Google Patents

Abstract

1323484 Dynamo-electric machines H BEYERSDORF 18 Dec 1970 [29 Dec 1969] 60128/70 Heading H2A A planar air gap dynamo-electric machine comprises a discoidal rotor 11 axially dispersed between two stators 21, 22, the rotor being toothed on both its axial sides, the stators carrying approximately radially extending A.C. windings 13, 14 and also each carrying an annular energizing winding 18, 19 disposed between the respective working air gap and an auxiliary air gap 23, 24 located radially within the working gap. The A.C. windings may be single- or poly-phase and are located in slots in laminated stator portions 15, 16. The rotor teeth may be substantially radial, Fig. 3 (not shown) or of curved formation, Fig. 5 (not shown) to reduce the harmonic content of the current in the A.C. windings. Instead of taking the form shown, the auxiliary air gaps may be cylindrical or radial; in the latter ease, Fig. 6 (not shown) the rotor includes a non-magnetic barrier (34) to prevent flux short-circuiting and consequent asymmetric magnetic attraction on the rotor. A cooling system for the rotor and windings is depicted in Fig. 7 (not shown). The air flowing over the rotor and windings is passed through a heat exchanger on one of the stators wherein it is cooled by liquid, e.g. water. The rotor and stator may be made of sintered or bonded ferrite material at least in the region of the working air gaps and the rotor may comprise a hub portion of coiled metal strip. The machine may operate as a generator or motor.