Power-assisted steering system
AssigneeMazda Motor Corporation
InventorToshihiko Yamamoto
Life of this patent
Estimating the term…
Abstract
A power-assisted steering system for an automotive vehicle has a steering shaft rotatably supported by a steering column, a steering wheel and an electric motor for assisting in rotating the steering shaft when the steering torque is too great. The electric motor has an output shaft offset from the steering shaft. A power-assisting structure includes a motor driven member and is mounted on the steering shaft for selectively connecting a steering torque transmitted from the steering wheel or the motor output transmitted from motor driven member to the steering shaft. A torque detector is disposed between the steering wheel and the steering shaft to detect a predetermined torque imparted to the steering wheel so as to actuate the electric motor, whereby assisting in rotating the steering shaft.
Claims18
A power-assisted steering system for an automotive vehicle having a steering shaft rotatably supported by a steering column and a steering wheel through which a steering torque is transmitted to said steering shaft, said steering system comprising:
- an electric motor mounted on said steering column having an output shaft offset from said steering shaft;
- a connecting structure, said connecting structure comprising a driven steering member fixed to said steering shaft, a drive member fixed to said steering wheel, a motor driven member engaging said output shaft disposed radially outwardly of said driven steering member, a clutch mechanism disposed between said motor driven member and said driven steering member, and at least one spring disposed between said driven steering member and said drive member, said at least one spring providing a torsional resistance to movement of said drive member relative to said driven steering member, said connecting structure selectively connecting said steering shaft to a steering torque transmitted from said steering wheel when said steering torque is smaller than a predetermined torque equal to said torsional resistance and a motor output transmitted from said output shaft when said steering torque is greater than said predetermined torque;
- and
- torque detecting means disposed in cooperation with said connecting structure for detecting said predetermined torque so as to actuate said electric motor, thereby rotating said output shaft and said motor driven member, engaging said clutch, and assisting in rotating said steering shaft.
Dependencies are inferred from the claim text.