A wheel is a circular component that is intended to rotate on an axial bearing. The wheel is one of the main components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing labor in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel and flywheel.
Common examples are found in transport applications. A wheel greatly reduces friction by facilitating motion by rolling together with the use of axles. In order for wheels to rotate, a moment needs to be applied to the wheel about its axis, either by way of gravity, or by the application of another external force or torque.
Famous quotes containing the word wheel:
“But if you know that you are a man too, and that even such are those that rule, learn this first of all: that all human affairs are a wheel which, as it turns, does not allow the same men always to be fortunate.”
—Herodotus (c. 484424 B.C.)
“It might become a wheel spoked red and white
In alternate stripes converging at a point
Of flame on the line, with a second wheel below,
Just rising, accompanying, arranged to cross,
Through weltering illuminations, humps
Of billows, downward, toward the drift-fire shore.”
—Wallace Stevens (18791955)
“Having a wheel and four legs of its own
Has never availed the cumbersome grindstone
To get it anywhere that I can see.”
—Robert Frost (18741963)