Rack And Pinion steering mechanism

How Rack And Pinion Steering Mechanism Works?


What Is Rack And Pinion Steering Mechanism?

The Rack and Pinion is a type of steering mechanism with a pair of gears which convert the rotary motion into the linear motion. This system consists of a circular gear called pinion engages with the teeth on the linear gear shaft called the rack. The rotary motion applied to the pinion causes it to turn while it moves rack sideways.

Rack and Pinion mechanical steering
mechanical version

This mechanism is simple and driver-friendly. It is the most effective and hence; widely used steering system by car manufacturers around the world. It is universally accepted that it is the best system to use. The mechanism consists of a pinion at the end of the steering column that meshes with the rack. The pinion is fixed to the steering column at its end. It meshes with the rack which moves either to the left or the right side depending upon the movement of the pinion.

Design:

In this steering mechanism, rack acts as the center section of the three piece rod. The rack has ball joints at each end that allow the up & down movement of the wheels. Also, there is a spring loaded pad underside the rack which reduces the backlash between the gears. The rack engages with the pinion mounted on the steering shaft. Furthermore, the ball joints further connect to the stub axles thru' tie rods.

The rotary motion of the steering wheel directly conveys to the wheels thru' the sideways movement of the rack. In case of most of the steering gears, on a right-hand drive car, the far-side wheel is steered directly while the near side wheel is driven thru’ the linkage. In case of light sports cars, this type of steering gear has significantly lower gear reduction.

How Rack and Pinion Steering works?

The rack always connects to either side of the steering wheel arms. The moving rack moves the wheel in either one or other way. The movements are usually part of a simple mechanism. The rotation of the steering shaft, thru' either hand or by a motor, converts rotary motion into linear motion. The load of the rack is usually minimal. However, it requires some torque because the gear ratio is low.

Rack and Pinion steering mechanism
hydraulic version

ZF, Rane TRW, & SKF are some of the leading manufacturers of this type of steering gears in the world.

Watch Rack and Pinion steering mechanism in action:

Read more: How Volvo Dynamic Steering works?>>

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