Cooling arrangement for an electric motor and method of fabricating a hollow shaft therefor

摘要

An electric motor includes a stator operable to produce a magnetic field and defining an opening, and a rotor at least partially disposed within the opening. The rotor includes a shaft extending along a rotational axis, a first rotor magnetic core portion including a plurality of laminations stacked contiguously on the shaft, and a second rotor magnetic core portion coupled to the plurality of laminations. The first rotor magnetic core portion and the second rotor magnetic core portion cooperate to define the rotor magnetic core. A plurality of windings is coupled to the rotor magnetic core and an air flow path is formed as part of the second rotor magnetic core portion. The air flow path includes an axial portion that passes through the shaft axially along the rotational axis and a radial portion that extends radially outward through the second rotor magnetic core portion. The present invention also discloses methods of fabricating a hollow shaft for the electric motor. 5203707_1 (GHMatters) P96541.AU 14/03/14 ,37 -' FIG. 1 ~5' PRIOR ART