Patent ID: 6991573

Claim:
A steering actuator of an independent type steer-by-wire system comprising: a housing fixed to a vehicle body; an ultrasonic motor having a stator internally fixed to said housing and a rotator rotating relative to said stator when an electric current is applied; a steering rod having a first end and a second end, the steering rod penetrating through a center portion of said ultrasonic motor, the first end of said steering rod extending out of said housing for connection to a tie rod; and a movement conversion means operably associated with said steering rod for converting rotating movement of said ultrasonic motor into linear movement of said steering rod, wherein said movement conversion means includes: a rotator ring gear integrally and internally formed at said rotator of said ultrasonic motor; a plurality of pinions each having a rotating shaft, said plurality of pinions being rotatably engaged with said rotator ring gear, said rotating shafts being fixed to said housing; a plurality of worm gears integrally connected to said pinions; and a plurality of racks formed at said steering rod so as to be engaged with said plurality of worm gears.