Patent attributes
A variable gear ratio steering apparatus has a steering operating member, a turning unit to turn a vehicle wheel and a gear ratio varying unit arranged between the steering operating member and the turning unit. The gear ratio varying unit comprises a differential gear mechanism, a gear ratio control motor and a steering torque assistance motor. The differential gear mechanism has a first internally toothed gear coupled to the steering operating member, a second internally toothed gear coupled to an input shaft of the turning unit and arranged coaxially with respect to the first internally toothed gear, at least one inside gear meshing with both the first and second internally toothed gears, and an inside gear support member rotatably supporting the inside gear. The gear ratio control motor is connected to the inside gear support part. The steering torque assistance motor is connected to the second internally toothed gear.
