GB197339A - Improvements in dynamo-electric machines - Google Patents

Abstract

197,339. Graichen, E. May 4, 1923. Rotary machines; cores; commutators and collecting-rings; terminals and accessories, arrangement on machine; field magnets, short-circuited screens on poles of.-A machine for generating continuous and alternating currents for motor-car lighting and ignition &c. comprises a field magnet rotating inside the armature which has a transformer and a condenser disposed around it. In the construction shown, the rotating field magnet 6 has series and shunt windings 9, 10, and permanent magnets 7, 8 at the sides. Bare copper rings 12 are placed around the poles to prevent eddy currents. A brush-holder 13 of fibre carries brushes 22, 22<a> in contact with the commutator 15, and continuous current is led to the terminals 24, 25 through the brushes 19, 23 and slip-rings 16, 17. Part of the outer circumference of the stator laminations is cut away to accommodate the transformer 29, 30 and condenser 31. A toothed wheel 35, driven at the speed of the engine cam shaft by a pinion 36 on the dynamo shaft, carries two carbon contacts 38, 39 in a fibre tube 37. Contact 39 slides on an insulated ring 40 connected to the secondary of the transformer, and contact 38 passes over the segments 51 of the distributor. A make-and-break device 46 mounted in the insulating plate 33 shortcircuits the primary, and is actuated by the wheel 35. A safety spark-gap 49, 50 is provided in the connection between the secondary and the ring 40. According to the Specification as open to inspection under Sect. 91 (3) (a), the field magnet may be fixed and the armature may rotate. This subject-matter does not appear in the Specification as accepted.