automotive steering

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automotive steering

[¦ȯd·ə¦mōd·iv ′stir·iŋ]
(mechanical engineering)
Mechanical means by which a driver controls the course of a moving automobile, bus, truck, or tractor.

Automotive steering

The means by which a motor vehicle is controlled about the vertical axis. It allows the driver to control the course of vehicle travel by turning the steering wheel, which turns the input shaft in the steering gear. The steering system has three major components: (1) the steering wheel and attached shaft in the steering column which transmit the driver's movement to the steering gear; (2) the steering gear that increases the mechanical advantage while changing the rotary motion of the steering wheel to linear motion; and (3) the steering linkage (including the tie rod and tie-rod ends) that carries the linear motion to the steering-knuckle arms. See Mechanical advantage

When the only energy source for the steering system is the force that the driver applies to the steering wheel, the vehicle has manual steering. When the driver's effort is assisted by hydraulic pressure from an electric or engine-driven pump, or by an electric motor, the vehicle has power-assisted steering, commonly known as power steering. Power steering allows manual steering to always be available, even if the engine is not running or the power-assist system fails.

Two types of automotive steering gears are rack-and-pinion and recirculating-ball. In a rack-and-pinion steering gear (see illustration), a tubular housing contains the toothed rack and a pinion gear. The housing is mounted rigidly to the vehicle body or frame to take the reaction to the steering effort. The pinion gear is attached to the lower end of the steering shaft, and meshes with rack teeth. Tie rods connect the ends of the rack to the steering-knuckle arms at the wheels. As the steering wheel turns, the pinion gear moves the rack right or left. This moves the tie rods and steering-knuckle arms, which turn the wheels in or out for steering.

Speed-sensitive rack-and-pinion power-steering system that provides variable assistenlarge picture
Speed-sensitive rack-and-pinion power-steering system that provides variable assist

In a recirculating-ball steering gear, a worm gear is attached to the lower end of the steering shaft. The worm gear turns inside a ball nut which rides on a set of recirculating ball bearings. These ball bearings roll in the grooves in the worm and inside the ball nut. Gear teeth on one outside flat of the ball nut mesh with a sector of teeth on the output or sector shaft to which the pitman arm is attached. As the steering wheel is turned, the rotary motion of the worm gear causes the ball nut to move up or down, forcing the sector shaft and pitman arm to rotate. This action moves the steering linkage to the right or left, turning the front wheels in or out for steering. See Antifriction bearing, Gear

References in periodicals archive ?
TechNavio's report, the Automotive Steering Market in India 2011-2015, has been prepared based on an in-depth analysis of the market with inputs from industry experts.
6% market share in China automotive steering system industry, while electric power system accounted for 24.
Since just-auto's last edition of automotive steerings systems was published in November 2008, the outlook for the automotive industry has significantly changed.
In this, the fifth edition of this report, just-auto reviews the key market drivers for automotive steering systems, and updates the market analysis.
The global automotive steering system market is highly concentrated in six big producers - JTEKT, ZF Lenksysteme, TRW, NSK, Mando and Nexteer, in which JTEKT and ZF Lenksysteme act as leaders with the respective market share of more than 15%.
Strong sales in industrial markets and the favorable impact of currency were partially offset by the impact of the strategic divestment of the company's automotive steering and European steel tube manufacturing operations.
1, 2015 /PRNewswire/ -- About automotive steering systems Automotive steering systems have evolved from being rigid to being more flexible, technologically advanced and reliable, smooth, and easy to use.
com adds Global and China Automotive Steering System Industry Report, 2014-2018 market research of 120 pages, published in February 2015, to the automotive and transportation intelligence collection of its store.
Strong sales in industrial markets were partially offset by the strategic divestment of the company's automotive steering and European steel operations.
NASDAQ:KBALB), announced today that the Company's Kimball Electronics-Poland facility has been awarded a major new business program to manufacture automotive steering systems for the European market.

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