Character print wheel with drive elements

摘要

A print wheel comprising a plurality of character elements for use in a serial impact printer such as a typewriter is directly attached to a rotor of a high performance rotary stepper motor. The rotor which is characterized by a high force-to-mass ratio includes a plurality of circumferentially spaced magnetic drive elements which are integrally formed with the rotor hub which also supports the print wheel. In one embodiment, the stator of the rotary motor forms an axial air gap between an active stator portion and an inactive stator portion, and the rotor and print wheel are removably mounted in the air gap. In another embodiment, the stator of the rotary motor forms a radial air gap between the active stator portion and the inactive stator portion.