GB191510711A - Improvements in Cooling or Ventilating Devices for Dynamo Electric Machines. - Google Patents

Abstract

10,711. Mond, A., [Maschinenfabrik Oerlikon]. July 23. A r m a t u r e s and field magnets, cooling; field magnets, dampers on poles of; coils; cores.-In a cooling-arrangement for cylindrical rotors, of the kind in which air passes axially through slots b arranged between the winding-slots a from both ends simultaneously towards the central part of the rotor and thence is discharged towards the stator c in a radial direction, the cooling-slots b are made of approximately the same radial depth as the winding-slots a and are provided with large radial outlets near the central part of the rotor, the walls of which act as fans when the rotor is running. The slots b give rise to increased magnetic saturation at the roots of the rotor teeth, producing a marked bend in the no-load characteristic. The cooling air is caused to bathe the coil-heads e, and slots f may be provided through the end caps, as shown. The bottoms of the cooling-slots b may be semicircular, and the tops of these slots may be partly closed by magnetic or other wedges g; these wedges may be of goodconducting material and may act as damper windings. The central openings may be distributed axially, as shown in Fig. 5. The bridges d which guide the cooling-air may be integral with the rotor, or may be inserted in axial slots extending the whole length of the machine.