Hitachi, Ltd.

Syoichi Maruyama

Kenji Mishima

Katuo Sugawara

Tohru Koyama

Toru Koyama

Katsuo Sugawara

Sinichi Yamashiro

Shinichi Yamashiro

Mitsuo Mashiko

A method of manufacturing electrical windings, according to which it is possible to manufacture, with high efficiency, the electrical windings differing in function and capable of performing the functions required of the respective windings. In the steps of forming the windings by winding the conductors and applying insulation on the windings, there are formed the insulating layers and suitable for the respective types of windings, viz. main pole coil interpole coil and compensating coils and a same impregnating resin is impregnated and hardened in each of said main pole coil interpole coil and compensating coils

Method of manufacturing electrical windings

In the production of electrically insulated coils which make up insulating layers, insulating material is wound around an electric conductor to form an insulating substrate, then impregnating varnish consisting of thermosetting resin is applied to the insulating substrate and hardened. In this electrically insulated coil production method, the impregnating varnish is made up of acid anhydride setting epoxy resin elements that include latent accelerators. These accelerators take more than 30 days to increase their initial viscosity by three times during storage at 25 degrees centigrade. After the insulating substrate is impregnated with the varnish, the substrate is heated at a temperature which will cause the impregnating varnish on the surface of the insulating substrate to lose its fluidity in under 30 minutes in order to preset the varnish. Next, the varnish is set at a heat at least 10 degrees centigrade lower than the presetting temperature and thereby, electrically insulated coils with high reliability are obtained.

Method for producing electrically insulated coils

Electrically insulated coils having excellent moisture resistance or water resistance utilize a simple material that is readily available. Using a simple method of manufacture, rotating electric machines such as motors for driving pumps, traction motors for rolling stocks and the like suitable for use in the outdoors may be built with the electrically insulated coils. The coils are coated with a fluorine-containing coating at least on portions which are exposed out of the side of the core. Since a uniform hydrophobic layer utilizing the repellent action of fluorine atoms is capable of being provided on the surface of the electrically insulated coils, the electrically insulated coils and the rotating electrical machines incorporating them feature excellent moisture resistance and water resistance.

Electrically insulated coils and a method of manufacturing thereof

Growing community of inventors

Yamatsuri, Japan

Syoichi Maruyama