The Steering is comprised of linkages which allow your vehicle to follow a desired path. The most conventional steering arrangement is to turn the front wheels using the steering wheel which is position in front of the driver via a steering column. This is usually done through a universal joint and be part of a collapsible steering column designed for road safety. The basic aim of the steering is to ensure that the wheels are pointing in the desired direction applied by the driver on the steering wheel.
Now for a technical explanation; This is typically achieved by a series of linkages, rods, pivots and gears. One of the fundamental concepts is that of the ‘caster angle’ – each wheel is steered with a pivot point ahead of the wheel, this makes the steering tend to be self-centering towards the direction of travel. The steering linkages connecting the steering box and the wheels usually conforms to a variation of ‘Ackermann’ steering geometry, to account for the fact that in turn, the inner wheel is actually travelling a path of smaller radius than the outer wheel, so that the degree of ‘toe’ suitable for driving in a straight path is not suitable for turning. The angle of the wheels on a vertical plane (‘Camber angle’) also influences steering dynamics.
Power steering helps the driver of a vehicle to steer by directing some of the power to assist in swivelling the steered road wheels about their steering axis. There are two types of power steering; hydraulic and electric/electronic. A hybrid version of both is now also possible to find on modern vehicles.
In a hydraulic power steering system it uses hydraulic pressure supplied by an engine driven pump to assist the motion of turning the steering wheel.
Where as Electric power steering is more efficient than the hydraulic power steering, since the electric power steering motor only needs to provide assistance when the steering wheel is turned, whereas the hydraulic pump must run constantly. In electric power steering system the amount of assistance is easily tuneable to the vehicle type, road speed and even driver preference. An additional benefit is the elimination of environmental hazards posed by leakage and disposal of hydraulic fluids. Yet also electrical assistance is not lost when the engine fails or stalls, where as hydraulic assistance stops when the engine stops, making the power steering extra heavy as the driver is now turning not only the heavy power steering system but also the power assistance system itself.