An electric motor assembly including an electric motor and a flywheel assembly. The electric motor includes a rotatable shaft, at least a portion of the shaft being tapered as the shaft extends from the electric motor to an outer end of the shaft, the outer end of the shaft being threaded to receive a securing member. The flywheel assembly, which optionally includes a pulley and/or fan, includes a bore extending through a center of the flywheel assembly, at least a portion of the bore being tapered as the bore extends from an inner periphery facing the electric motor to the outer periphery of the flywheel assembly. The shaft of the electric motor extends through the bore of the flywheel assembly such that the taper of the shaft and the bore center the flywheel-pulley assembly on the shaft and create a self-holding taper arrangement. A securing member can be secured onto the outer end of the shaft to fix the flywheel assembly axially. Methods of forming and use are also provided.
