An Introduction to Sprockets

An Introduction to Sprockets

The rotation of a sprocket and its shaft transmits power to the chain, and the chain passes it on through a second sprocket to another shaft. By hub shape, sprockets fall into three types: A type (plate), B type (hub on one side) and C type (hub on both sides).

With a belt drive an exact, constant speed ratio cannot be obtained; with a gear drive the two shafts cannot be far apart. So when the speed ratio between two shafts must be exact but the distance is too great for gears, a chain drive is the most suitable choice.

Advantages of chain and sprocket drives

• There is no slip, so the speed ratio is exact.
• Only the tight side is under tension while the slack side carries almost none, so the effective pull is high and transmission efficiency is good; bearing loads are low, so wear is reduced.
• Power is transmitted regardless of moisture, cold or heat, so service life is long.
• It suits both short and long shaft centre distances.
• Chain length is easy to adjust, and a broken chain is easy to repair.