Patent ID: 9653967
Date: 2017-05-16
CPC Classifications: H02K

Claim:
1. An electric motor comprising: a stator operable to produce a magnetic field, the stator defining an opening; and a rotor at least partially disposed within the opening, the rotor comprising, a shaft extending along a rotational axis; a first rotor magnetic core portion including a first plurality of laminations stacked contiguously on the shaft, each lamination including a predetermined number of teeth; a second rotor magnetic core portion coupled to the first rotor magnetic core portion, the second rotor magnetic core portion including a second plurality of laminations, each of the second plurality of laminations including at least one less than the predetermined number of teeth and a slot that extends radially through the lamination, the first rotor magnetic core portion and the second rotor magnetic core portion cooperating to define at least a portion of a rotor magnetic core; wherein each of the second plurality of laminations includes a central aperture for the shaft and an exterior and wherein the slot extends from the central aperture to the exterior surface to define a continuous passage radially through the lamination; a plurality of windings coupled to the rotor magnetic core; and an air flow path formed as part of the second rotor magnetic core portion, the airflow path including an axial portion that passes through the shaft axially along the rotational axis and a radial portion formed by the slots that extends radially outward through the second rotor magnetic core portion.