Also known as a roller chain, a sprocket chain is a type of chain that is mainly used for the transmission of mechanical power. These chains can be found in many different machines and are most commonly found on two-wheeled vehicles, such as bicycles and motorcycles. A sprocket chain runs along two or more sprockets, where mechanical rotational energy is transferred. Sprocket chains are known to be incredibly reliable, simple, and efficient in operation. They have been employed in many different mechanical applications.
The construction of a sprocket chain is relatively simple and consists of sets of inner and outer plates. These plates make up each link of the chain. Two outer plates will hold an inner plate, resulting in an alternating pattern of inner and outer plates forming the links. There are two different types of sprocket chains depending on how the plates are held together. Some have bushings, while others do not.
A sprocket chain with bushings will often deliver the best performance due to less friction, but is more expensive and complicated to manufacture. The linkage consists of a bushing between the two plates of an inner link. Inside these bushings is a pin, which couples them to the outer links. Some sprocket chains, however, employ a different type of linkage system. Instead of using a bushing and pin, a tube is stamped into the inner plates along with holes to hold everything together. While less expensive than a sprocket chain with bushings, these types typically do not perform quite as well.
Lubrication is considered an important part of sprocket chain maintenance and can vary depending on the environment in which the chain is located. Ideally, sprocket chains operate in a closed and controlled environment, free from contaminants that could ultimately increase friction. Many machines that employ a sprocket chain will often keep them inside a separate chamber, where they can be protected and lubricated on a regular basis. Depending on the machine, however, a sprocket chain may need to be exposed to harsh environments. A great example of this is a bicycle or motorcycle sprocket chain, where the chain is commonly exposed to dirt and other contaminants.
Sprocket roller chains are not exclusive to vehicles such as bicycles, however. Another common application is a chainsaw, where the chain itself makes up the blades of the saw. The sprockets on either end revolve at high speeds, helping the chainsaw cut through many different materials. A sprocket chain can also be found on internal combustion engines, serving as a more reliable alternative to mass-produced timing belts.