GB190606223A - Improvements in Dynamo Electric Machines. - Google Patents

Abstract

6223. Hunt, L. J., and Sandycroft Foundry Co. March 14. Armatures; field magnets; rotary converters.- The rotors of machines having two or more windings of different pole-numbers on the rotor and stator adapted for cascade connexion, as described in Specification No. 14,401, A.D. 1905, or having the equivalent cross-connected windings described in Specification No. 6224, A.D. 1906, are fitted with one or more commutators, the machines then serving as self-excited alternators, rotary converters, repulsion motors, &c. In the arrangement shown in Fig. 1, the rotor windings 2, 4 are connected by slip-rings k . . . p, and the winding 4 is connected to a commutator 29 on which bear brushes 30. On the stator winding 1 being excited with alternating current and the second stator winding 3 with continuous current, the machine works as a rotary converter. If the winding 3 is connected to the brushes 30 and the machine mechanically rotated, it becomes a self-exciting alternator, or both stator windings may be fed with continuous current from the brushes 30, and the slip-rings k, m, o connected to supply the mains. If the rotor winding 2 is connected to the stator winding 3 through a pair of slip-rings and in series with the brushes 30, the machine works as a series motor; on short-circuiting the brushes 30, as a repulsion motor ; or, by providing an extra pair of shortcircuited brushes at right-angles to the brushes 30, as a series repulsion motor. In the arrangement shown in Fig. 3, the rotor connexions are broken, each rotor winding is connected to a commutator, and both stator windings are excited by continuous current, the machine then acting as a continuouscurrent tranformer, which may be used as a booster, balancer, &c. One stator winding may serve as a commutating-winding for the other by suitably arranging their magnetic axes. In another modification, Fig. 4, a compounded alternator is obtained by connecting the rotor and stator windings through the commutators and arranging an auxiliary winding 33 to assist the winding 3, current being taken from slip-rings r, s.