A reliable and cost-efficient direct drive force feedback motor is
suitable for joystick applications, allowing multiple degrees of output
freedom, requiring no coil commutation, and permitting compact packaging.
A multiple degree-of-freedom motor consistent with the invention
comprises an output shaft, a stator, and a rotor. The stator comprises
first and second lamination stacks, each lamination stack having an
interior curved surface and a coil wound thereon, the lamination stacks
being disposed adjacent the output shaft. The rotor is fixed to the
output shaft and movably supported adjacent the stator with an air gap
disposed between the rotor and the stator, the rotor including at least
one magnet disposed thereon and being movable along the interior curved
surface of the lamination stacks in directions defining at least first
and second degrees of freedom. Energization of the coil of the first
lamination stack establishes a first magnetic field to urge the output
shaft to rotate in a first plane, and energization of the coil of the
second lamination stack establishes a second magnetic field to urge the
output shaft to rotate in a second plane substantially orthogonal to the
first plane.