Field Structure

Author: E.E. Kimberly

In most direct-current generators the frame is used as part of the magnetic circuit. Fig. 10-12 shows a common type of construction. The pole pieces are usually built up of rather thick (1/16) laminations and are either cast in the frame or bolted to it. The bolted type of construction permits removal, for repair, of a pole piece with its exciting coil without disturbing other parts of the generator. The exciting coils on the pole pieces are connected in series in such manner that the current in them produces north and south poles alternately around the frame, as in Figs. 10-6 and 10-8.

Fig. 10-12. Direct-Current Generator Frame