An internal permanent magnet machine includes a rotor assembly having a shaft comprising a plurality of protrusions extending radially outward from a main shaft body and being formed circumferentially about the main shaft body and along an axial length of the main shaft body. A plurality of stacks of laminations are arranged circumferentially about the shaft to receive the plurality of protrusions therein, with each stack of laminations including a plurality of lamination groups arranged axially along a length of the shaft and with permanent magnets being disposed between the stacks of laminations. Each of the laminations includes a shaft protrusion cut formed therein to receive a respective shaft protrusion and, for each of the stacks of laminations, the shaft protrusion cuts formed in the laminations of a respective lamination group are angularly offset from the shaft protrusion cuts formed in the laminations in an adjacent lamination group.
GOVERNMENT LICENSE RIGHTS
This invention was made with Government support under contract number DE-EE0005573 awarded by the United States Department of Energy. The Government has certain rights in the invention.