| 摘要 |
480,245. Dynamo - electric machines. LA ROVERE, G. May 15, 1936, No. 13843. [Class 35] A dynamo-electric machine; particularly for high-tension, has a salient pole armature and field magnet, the armature having two windings in parallel, each pole carrying a coil of each winding, and the number of armature poles differs from that of the field poles by an odd number ; means for injecting an alternating voltage to improve commutation are also described. Fig. 1 shows a machine with a rotating field magnet having six poles excited by a separate machine and seven armature poles A .. G. The windings on successive armature poles a,re wound in opposite directions and the coils of one winding are alternately nearer to and further from the axis than those of the other. The armature poles may carry damping windings of the ordinary type and in addition current is supplied to the coils undergoing commutation by an alternator M. The terminals 1 .. 14 of the armature windings are connected to commutator segments similarly numbered on two rings on which bear two sets of brushes rotating with the field magnet. The alternator M has two armature windings connected through slip-rings to the two sets of brashes so 'as to supply current for improving commutation. Fig. 2 shows an alternative form of commutator in which the segments occupy one-sixth of the circumference only. The alternator M may be connected to the brushes through a transformer' and the circuit may include a condenser. - In a modification the condenser is omitted and the commutation-improving voltage obtained by resonance only. A biphase alternator co-operating with four banks of brushes may also be employed. The Specification as open to inspection under Sect. 91 describes arrangements in which the numbers of armature and field poles differ by an even number and the armature poles carry one winding only, but the description is not clear. This subject matter does not appear in the Specification as accepted. |
