Automotive Steering Systems
In a typical mechanical steering system the driver’s steering input is transmitted by a steering shaft through some type of gear reduction mechanism to generate steering motion at the front wheels. In the present day automobiles, power steering assist has become a standard feature. A hydraulic power steering uses hydraulic pressure supplied by an engine-driven pump. Power steering amplifies and supplements the driver-applied torque at the steering wheel so that steering effort is reduced. The recent introduction of electric power steering in production vehicles eliminates the need for the hydraulic pump. Electric power steering is more efficient than conventional power steering, since the electric power steering motor only needs to provide assist when the steering wheel is turned, whereas the hydraulic pump must run constantly. The assist level is also easily tunable to the vehicle type, road speed, and even driver preference. An added benefit is the elimination of environmental hazard posed by leakage and disposal of hydraulic power steering fluid. Types of steering system
1. Electric systems
Electric power steering (EPS or EPAS) is designed to use an electric motor to reduce effort by providing steering assist to the driver of a vehicle. Sensors detect the motion and torque of the steering column, and a computer module applies assistive torque via an electric motor coupled directly to either the steering gear or steering column. This allows varying amounts of assistance to be applied depending on driving conditions. On Fiat group cars the amount of assistance can be regulated using a button named "CITY" that switches between two different assist curves, while most other EPS systems have variable assist, which allows for more assistance as the speed of a vehicle decreases and less assistance from the system during high-speed situations. In the event of component failure, a mechanical linkage such as a rack and pinion serves as...
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