Patent ID: 7963529

Claim:
An apparatus comprising: a first rotary motor comprising a first motor housing coupled to a support structure; a second rotary motor comprising a second motor housing coupled to said support structure; a transmission coupled to the first and second rotary motors comprising: a first ball nut having a first thread direction coupled to the first rotary motor, a second ball nut having a second thread direction opposite the first direction coupled to the second rotary motor a ball screw having a first threaded region matching the thread direction of the first ball nut and a second threaded region matching the thread direction of the second ball nut; wherein the transmission converts rotation of the first rotary motor in a first direction and simultaneous rotation of the second rotary motor in a second direction which is opposite the first direction to linear motion of an output shaft in a single direction, wherein the reaction torque applied by the pair of oppositely rotating rotary motors to said support structure is reduced compared to the reaction torque applied to said support structure by a single one of the first and second rotary motors operating alone.