Patent ID: 8766493

Claim:
An electric device comprising: an actuator including a coil having an axis; and a stator assembly comprising: a stator core arranged along a linear axis, said stator core comprising a first plurality of magnets each characterized by a magnetic moment, said first plurality of magnets arranged in a stack along said linear axis with the magnet moments of the first plurality of magnets being co-linearly aligned parallel to the linear axis, wherein the magnetic moments of the plurality of magnets reverse direction along the linear axis at a boundary between neighboring magnets of said plurality of magnets, and wherein the actuator is arranged on the stator core with the coil of the actuator encircling the linear axis and the first plurality of magnets with the axis of the coil parallel to the linear axis, said stator core further comprising a second plurality of magnets arranged outside of the coil with the coil positioned between the first plurality of magnets and the second plurality of magnets, said magnets of the second plurality of magnets in positions fixed relative to the first plurality of magnets.