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RACK AND PINION

SUDHAN

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STEERING SYSTEMRACK AND PINION STEERINGPOWER STEERINGPOWER RACK AND PINIONBASIC COMPONENTSWORKINGADVANTAGESBIBLIOGRAPHY

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Any mode of transportation used by people must have means of control. For the automobile, two primary csystems are at the driver's disposal: (1) the steering system(2) the braking system.The steering mechanism converts the driver's rotational in

the steering wheel into a change in the steering angle vehicle's steering road wheels.

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For a car to turn smoothly, each wheel mustfollow a different circle. Since the insidewheel is following a circle with a smallerradius, it is actually making a tighter turnthan the outside wheel. If you draw a lineperpendicular to each wheel, the lineswill intersect at the center point of the turn.The geometry of the steering linkage makes

the inside wheel turn more than the outsidewheel.

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Basically, as the name implies, the rack-and-pinion sconsists of a rack and a pinion, The steering ratio is definthe ratio of pinion revolutions (steering-wheel revolutiorack travel. Suitable toothing of the rack allows the ratiomade variable over the travel. This lowers the actuating foreduces the travel for steering corrections.

Rack-and-pinion steering is quickly becoming tcommon type of steering on cars, small trucks. It is actpretty simple mechanism. A rack-and-pinion gearset is encin a metal tube, with each end of the rack protruding frotube. A rod, called a tie rod , connects to each end of the

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The pinion gear is attached to the steering shaft . Whethe steering wheel, the gear spins, moving the rack.

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The rack-and-pinion gearset does two things:It converts the rotational motion of the steering wheel inlinear motion needed to turn the wheels.It provides a gear reduction, making it easier to turn the whOn most cars, it takes three to four complete revolutions

steering wheel to make the wheels turn from lock to lockfar left to far right).

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The primary components of the rack and pinion steering sare:

Rubber bellowsPinion

RackInner ball joint or socketTie-rod

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Power steering helps drivers steer vehicles by increasingsteering effort of the steering wheel. Hydraulic or electricactuators add controlled energy to the steering mechanism, the driver needs to provide only slight effort regardless ofconditions. Power steering helps considerably when a vehicstopped or moving slowly. As well, power steering providesome feedback of forces acting on the front wheels to give ongoing sense of how the wheels are interacting with the rothis is typically called " rad feel"

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Representative power steering for cars increase steering effortactuator, a hydraulic cylinder, wpart of a servo system. These have a direct mechanical conbetween the steering wheel alinkage that steers the wheelmeans that power-steering systemstill permits the vehicle to be using manual effort alone.

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When the rack-and-pinion is in a power-steering system, thrack has a slightly different design.

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Part of the rack contains a cylinder with a piston in the midThe piston is connected to the rack. There are two fluid porone on either side of the piston. Supplying higher-pressure to one side of the piston forces the piston to move, which inmoves the rack, providing the power assist.

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Pump

The hydraulic power for the steering is provided by a rotapump . This pump is driven by the car's engine via a belt and pIt contains a set of retractable vanes that spin inside an ovalchamber.

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The pump contains a pressure-relief valve to make sure thapressure does not get too high, especially at high engine spwhen so much fluid is being pumped.

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The steering effort is considerably reduced.The vehicle can be steered lock to lock with approximatelyand half steering wheel turns.The hydraulics of power steering system absorbs the roadshocks.

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www.Wikipedia.org www.howstuffworks.com

http://www.wikipedia.org/http://www.howstuffworks.com/http://www.howstuffworks.com/http://www.wikipedia.org/

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