Patent ID: 6919656

Claim:
An electric asynchronous motor for driving one of a shaft, a roll shell and a machine element, comprising: a housing; an annular stator having a first face at one end of said stator and a second face at an other end of said stator; an annular rotor having a first face at one end of said rotor and a second face at an other end of said rotor, said rotor at least partially disposed within said stator, both said stator and said rotor disposed within said housing; at least one connecting element; a motor shaft connected to said rotor by said at least one connecting element; and a cooling system disposed substantially in said housing, including: a cooling liquid; at least one annular heat exchanger disposed within said housing proximate at least one said face of said rotor, said at least one annular heat exchanger carrying said cooling liquid; and at least one annular air circulation channel in at least one of said annular stator and said annular rotor, said at least one annular air circulation channel being configured to guide air streams from at least one of said first face of said stator and said first face of said rotor to at least one of said second face of said stator and said second face of said rotor; wherein said cooling system is configured to provide an internal cooling air circuit by way of an air stream flowing proximate said at least one annular air circulation channel, said rotor, said stator, said shaft and said heat exchanger, said internal cooling air circuit defining an internal toroidal air stream.