A sprocket[1] or sprocket-wheel[2] is a profiled wheel with the teeth, or cogs,[3][4] that mesh with a chain, track or other perforated or indented material.[5][6] The name ‘sprocket’ applies generally to any wheel upon which radial projections engage a chain passing over it. It really is distinguished from a equipment in that sprockets should never be meshed together straight, and differs from a chain sprocket pulley in that sprockets have teeth and pulleys are soft.
Sprockets are used in bicycles, motorcycles, cars, tracked vehicles, and other machinery either to transmit rotary movement between two shafts where gears are unsuitable or to impart linear motion to a track, tape etc. Probably the most common form of sprocket could be within the bicycle, in which the pedal shaft bears a big sprocket-wheel, which drives a chain, which, in turn, drives a small sprocket on the axle of the trunk wheel. Early automobiles were also largely driven by sprocket and chain mechanism, a practice mainly copied from bicycles.
Sprockets are of varied designs, no more than efficiency becoming claimed for every by the originator. Sprockets typically don’t have a flange. Some sprockets used in combination with timing belts have flanges to keep the timing belt centered. Sprockets and chains are also utilized for power transmission in one shaft to some other where slippage is not admissible, sprocket chains being used rather than belts or ropes and sprocket-wheels rather than pulleys. They could be operate at high speed plus some forms of chain are so built as to be noiseless actually at high speed.