|Also called: power-assisted steering a form of steering used on vehicles, where the torque applied to the steering wheel is augmented by engine power|
system to aid the steering of an automobile by use of a hydraulic device (driven from the engine) that amplifies the turning moment, or torque, applied to the steering wheel by the driver. To reduce the torque required from the driver as cars became heavier and tires softer, gears were introduced between the steering wheel shaft and the linkage that turns the wheels. The gears multiplied the torque supplied by the driver to a much greater torque on the shaft that drives the front wheels to right or left. A disadvantage arose, however, in the higher steering ratio required; i.e., amount of turn of the steering wheel needed.
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