Power steering helps drivers steer vehicles by augmenting steering effort of the steering wheel. Hydraulic or electric actuators add controlled energy to the steering mechanism, so the driver needs to provide only modest effort regardless of conditions. Power steering helps considerably when a vehicle is stopped or moving slowly. Also, power steering provides some feedback of forces acting on the front wheels to give an ongoing sense of how the wheels are interacting with the road; this is typically called "rοad feel".
Representative power steering systems for cars augment steering effort via an actuator, a hydraulic cylinder, which is part of a servo system. These systems have a direct mechanical connection between the steering wheel and the linkage that steers the wheels. This means that power-steering system failure (to augment effort) still permits the vehicle to be steered using manual effort alone.
Other power steering systems (such as those in the largest off-road construction vehicles) have no direct mechanical connection to the steering linkage; they require power. Systems of this kind, with no mechanical connection, are sometimes called "drive by wire" or "steer by wire", by analogy with aviation's "fly-by-wire". In this context, "wire" refers to electrical cables that carry power and data, not thin-wire-rope mechanical control cables.
In other power steering systems, electric motors provide the assistance instead of hydraulic systems. As with hydraulic types, power to the actuator (motor, in this case) is controlled by the rest of the power-steering system.
Some construction vehicles have a two-part frame with a rugged hinge in the middle; this hinge allows the front and rear axles to become non-parallel to steer the vehicle. Opposing hydraulic cylinders move the halves of the frame relative to each other to steer.
Other articles related to "steering, power steering, power":
... Steering wheels for passenger automobiles are generally circular, and are mounted to the steering column by a hub connected to the outer ring of the steering wheel ... In countries where cars must drive on the left side of the road, the steering wheel is typically on the right side of the car (right-hand drive or RHD) the converse applies ... In addition to its use in steering, the steering wheel is the usual location for a button to activate the car's horn ...
... launched the S2000 Type V equipped with the world's first electric power variable gear ratio steering (VGS) system ... In 2003, Toyota introduced their own "Variable Gear Ratio Steering (VGRS)" system introduced on the Lexus LX 470 and Landcruiser Cygnus, and also incorporated the ... In 2003, BMW introduced their "Active Steering" system on the 5-series ...
... An outgrowth of power steering is speed sensitive steering, where the steering is heavily assisted at low speed and lightly assisted at high speed ... that motorists might need to make large steering inputs while manoeuvering for parking, but not while traveling at high speed ... the amount of assistance as in modern power steering systems, it altered the pressure on a centring cam which made the steering wheel try to "spring" back to the straight-ahead position ...
... DIRAVI is the name given by Citroën to its proprietary power steering system, first seen in 1970 ... acronym for "Direction à rappel asservi" literally meaning "steering with controlled return" more accurately described in English as "power steering with power ... This was the first commercially available variable assist power steering arrangement, allowing the motorist power assist when parking, but recognizing that less steering ...
... Power steering is supplied as standard ... not available on an electric vehicle, an electric motor is used to power a power steering hydraulic pump ...
Famous quotes containing the words steering and/or power:
“Behind the steering wheel
The boy took out his own forehead.
His girlfriends head was a green bag
Of narcissus stems. OK you win
But meet me anyway at Cohens Drug Store
In 22 minutes.”
—John Ashbery (b. 1927)
“First, there is the power of the Wind, constantly exerted over the globe.... Here is an almost incalculable power at our disposal, yet how trifling the use we make of it! It only serves to turn a few mills, blow a few vessels across the ocean, and a few trivial ends besides. What a poor compliment do we pay to our indefatigable and energetic servant!”
—Henry David Thoreau (18171862)