Patent ID: 7815535

Claim:
A drive for imparting rotation about an axis; said drive comprising; a housing; an axial flux motor located in the housing and including a stator having axially spaced windings and a radially directed rotor that is located between the windings and revolves about the axis; and a transmission located within and surrounded by the motor, the transmission including a first ring gear that is fixed in position with respect to the housing, a second ring gear that rotates about the axis, and a carrier that rotates about the axis and is coupled to the rotor of the axial flux motor so that the motor will apply torque to and impart rotation to the carrier, the carrier having spaced apart walls and pins that extend between the walls, the transmission further including planet gear clusters that rotate on the pins of the carrier and orbit about the axis when the carrier rotates, with each cluster having united first and second planet gears that are offset axially from each other, the first planet gear of each cluster being larger than the second planet gear of the cluster and being engaged with the first ring gear, the second planet gear of each cluster being engaged with the second ring gear to drive the second ring gear, a drive spindle connected to the second ring gear, and a drive flange coupled with and driven by the second ring gear through the drive spindle, the drive flange being exposed beyond the housing and including a sleeve that projects into the housing and receives the drive spindle and is coupled with a key or spline to the drive spindle; and an antifriction bearing located between the sleeve of the drive flange and the housing.