Wheel

Wheel is the name of a circular disc or torus shaped object. It is a primitive machine? the fundamental operation of which is to transfer linear motion (that is, going along) into rotary motion (that is, going around).

Wheels can be fastened on a [wheel axle]? and attached to a vehicle. The wheel will then roll over the ground. Compared to a vehicle without wheels, a sled? say, the friction from "ground against vehicle" is largely eliminated and replaced with friction from "wheel axle against socket", where a lubricant or [ball bearing]?s may minimize it. Movement along is thereby achieved with much less friction which means much less work is necessary.

In order for wheeled vehicles to work well, one must employ them on roads, or fit the vehicle with superior suspension?.

Variations on wheels produce the pulley and the windlass?.

The wheel was most likely invented in all ancient civilizations, although not always used. A development of wheels to allow them to travel through rough terrain is the track.

The wheel is often viewed as the quintessential invention?.

/Talk