Siemens Aktiengesellschaft

Joachim Eckert

Franz Spirk

A turbine type synchronous motor capable of starting directly and asynchronously when coupled to a work-performing machine is constructed with a drum rotor of high mass, made of solid magnetic material containing iron, and having no damper winding. The field windings, short-circuited or closed through a resistance during starting, are radially disposed in insulated slots which are closed by insulated wedges wherein the insulation is of highly temperature resistant material.

Synchronous turbine type electric motor

In an asynchronous machine including a rotor of solid iron and a squirrel cage winding, the rotor is further provided with closed slots of any cross sectional shape which receive the bars of the squirrel cage winding whose upper edge is spaced from the outer surface of the rotor by a distance which is equal to the depth of penetration a of the eddy currents generated for a given starting voltage and for a slip s.gtoreq.0.8.

Growing community of inventors

Berlin, Germany

Joachim Eckert