Patent ID: 7489057
Filing Date: 2009-02-10
Classification: H02K

Abstract:
1. An electric motor cooling system comprising: an electric motor rotor assembly comprised of a rotor rigidly coupled to a rotor shaft, said rotor shaft comprised of an open end located at a first end of said rotor shaft and along a centerline defined by a long axis of said rotor shaft, a closed end located at a second end of said rotor shaft and along said rotor shaft centerline, and a hollow portion between said open end and said closed end and located coaxially along said rotor shaft centerline; a coolant feed tube extending through said open end of said rotor shaft and positioned within said hollow portion of said rotor shaft, said coolant feed tube comprised of a first open end located at a first end of said coolant feed tube and along a centerline defined by a long axis of said coolant feed tube, a second open end located at a second end of said coolant feed tube and along said coolant feed tube centerline, and a hollow portion therebetween defining a first coolant flow path, said first open end of said coolant feed tube defining a coolant inlet, said second open end of said coolant feed tube defining a coolant outlet, said second open end of said coolant feed tube proximate to and spaced apart from said closed end of said rotor shaft, wherein a separation between an outer, lengthwise surface of said coolant feed tube and an inner, lengthwise surface of said hollow portion of said rotor shaft defines a second coolant flow path, wherein coolant exiting said second open end of said coolant feed tube is redirected from said first coolant flow path to said second coolant flow path by an inner surface of said rotor shaft corresponding to said closed end of said rotor shaft; means for rigidly coupling said coolant feed tube to said rotor shaft; and means for pumping coolant through said coolant inlet of said coolant feed tube, through said first coolant flow path, through said coolant outlet of said coolant feed tube, through said second coolant flow path, and through said open end of said rotor shaft.