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Power Steering - How Car Steering Works

Power Steering - How Car Steering Works
There are a couple of key components in power steering in addition to the rack-and-pinion or recirculating-ball mechanism. Pump The hydraulic power for the steering is provided by a rotary-vane pump (see diagram below). As the vanes spin, they pull hydraulic fluid from the return line at low pressure and force it into the outlet at high pressure. The pump contains a pressure-relief valve to make sure that the pressure does not get too high, especially at high engine speeds when so much fluid is being pumped. Rotary Valve A power-steering system should assist the driver only when he is exerting force on the steering wheel (such as when starting a turn). The key to the rotary valve is a torsion bar. The input from the steering shaft forms the inner part of a spool-valve assembly. Animation showing what happens inside the rotary valve when you first start to turn the steering wheel As the bar twists, it rotates the inside of the spool valve relative to the outside. Related:  Suspension

eps system Steering column EPS system 1 Steering gearbox Caster, Camber, Toe The following article is reprinted with the permission of Grassroots Motorsports magazine. For more information from this fine publication, please point your browser to Grassroots Motorsports magazine. Pointed the Right Way story by john hagerman Camber, Caster and Toe: What Do They Mean? The three major alignment parameters on a car are toe, camber, and caster. When a pair of wheels is set so that their leading edges are pointed slightly towards each other, the wheel pair is said to have toe-in. For minimum tire wear and power loss, the wheels on a given axle of a car should point directly ahead when the car is running in a straight line. So if minimum tire wear and power loss are achieved with zero toe, why have any toe angles at all? When the wheel on one side of the car encounters a disturbance, that wheel is pulled rearward about its steering axis. With toe-in (left) a deflection of the suspension does not cause the wheels to initiate a turn as with toe-out (right).

What is steering Gearbox? KPI and included angle basics | Technical Theory | Car Tyres Fitting and Wheel Alignment Specialists K.P.I - kingpin inclination, S.A.I - swivel arm inclination, B.J.I - ball joint inclination, The kpi is the angle formed between the true vertical, and the centre line through the ball joints or struts, the term kpi is no longer relevant since it is reliant on older forms of construction, in fact, as far back as the horse and cart, the evolution of new technology forming the cars geometry, commanded new terminology such as S.A.I and B.J.I, my preference is K.P.I as this term is recognized globally, The kpi is designed into the suspension system and is there to aid keeping the wheels straight, and to aid self centring of the steering, to understand how this is achieved, it is necessary to imagine a system with 0 degree kpi. As there is a resistance between the tyre and the road surface, this makes the wheel want to turn around ( in this case ) the upper and lower swivel joints, with equal force on the front tyres, this results in a force that tries to compress the steering rack. Summary

Ball joints Home Page Here we tackle the tough questions : "Ackerman? Or not? Dale Thompson from Racing Car Technology looks for some answers. Ackerman? Ackerman steering geometry is used to change the dynamic toe setting, by increasing front wheel toe out as the car is turned into the corner. Our interest at Racing Car Technology is to look for further developments in racing car set up for our customers. Ackerman Steering Geometry Figure 1 The typical steering system, in a road or race car, has tie-rod linkages and steering arms that form an approximate parallelogram, which skews to one side as the wheels turn. Full Ackerman geometry requires steering angles, inner wheel and outer wheel, as per Figure 1. In practise, the steering angles achieved are not perfect Ackerman geometry. We will also look at the static toe setting, because of it's interaction with Ackerman. Suspension movement may also cause changes in toe (bump steer). Tyre Slip Angle - the major variable in the Ackerman story Figure 2 Figure 3 Figure 4

Purpose of Ball Joints? Camber, Caster, Toe-in/Toe-out, explained - Intrax Racing TOE-IN / TOE-OUT Affects 3 majore areas; Tire wear, straight-line stability and corner entry handling. For minimum tire-wear it would be ideal to have the wheels parralel / 0 degrees while riding. This can be acomplished to give a bit static toe-out to a frontwheel-drive car, or toe-in to a rearwheel-driver. A frontwheel-drive car has the tendency to understeer. Excessive toe-in will cause the tire to scrub on the outboards and so will shorten the tire-life. Steering response will be improved with toe-out. Sometimes toe-in or toe-out is used for another effect; Tire-temperature. Street cars often are set up with toe-in; For good straight-line stability cornering is sacrefied. If the suspension is independent; Toe-in or -out can also be applied to the rear-wheels. Also there's a difference between static and dynamic toe.

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