摘要 |
1,269,019. Coils for dynamo-electric machines. GENERAL ELECTRIC CO. 9 March, 1970 [14 April, 1969], No. 11118/70. Heading H2A. [Also in Division H1] In making a coil, e.g. for a salient pole in a dynamo-electric machine, a plurality of turns of insulated wire are wound on a former, the coil so formed is wrapped with heat shrinkable material leaving openings in the resulting layer of shrinkable material, insulating liquid varnish is applied to the wrapped coil and the coil then heated to shrink the wrapping material so as to compress the coil and at least partially cure the varnish so as to fill the voids between the turns of wire. The openings in the shrinkable material may be formed by skip taping, Fig. 1 (not shown) or by using porous wrapping material. The coil which may be random wound may be bent to its final desired shape after the wrapping operation. The varnish may be poured or sprayed on the wrapped coil or the coil may be immersed in a bath of varnish. The coil may finally be provided with layers of insulating and protective material. Irradiated polyethylene tape or polyethylene terephthalate tape may be used as the heat shrinkable material. Synthetic polyester resin or a silicone may be used as the varnish. |