Totally enclosed electric motor

In a totally enclosed electromotive device having a stator and a rotor in a stator-rotor arrangement, said stator being fixedly supported by an internal cylindrical wall of a main housing for said device and the rotor being rotatably mounted in front and rear housings of said device on suitable bearings therein, said front and rear housings being detachably secured to said main housing, the improvement comprising:

• an internal ventilation system comprising an internal fan driven by said rotor disposed in an internal fan compartment defined between said stator-rotor arrangement and said rear housing, a series of annular internal longitudinally extending ducts surrounding the internal cylindrical wall of the main housing and communicating with said fan compartment, and means for directing the internal ventilating air from said internal ducts to said stator-rotor arrangement to return to said internal fan compartment, and
• an external ventilation system comprising an external fan driven by said rotor disposed in an external fan compartment defined by said rear housing and an exterior rear cover, said rear housing sealing said external fan compartment from said internal ventilation system, a series of annular external longitudinally extending ducts in said main housing discharging into exhaust compartment which exhausts to the atmosphere arranged in said front housing, said exhaust compartment means being sealed from said internal ventilation system by said front housing.