Chain drive

The oldest known application of a chain drive appears in the Polybolos, described by the Greek engineer Philon of Byzantium (3rd century BC).

Two flat-linked chains were connected to a windlass, which by winding back and forth would automatically fire the machine's arrows until its magazine was empty.

[3] Although the device did not transmit power continuously since the chains "did not transmit power from shaft to shaft, and hence they were not in the direct line of ancestry of the chain-drive proper",[4] the Greek design marks the beginning of the history of the chain drive since "no earlier instance of such a cam is known, and none as complex is known until the 16th century.

[7] The chain drive itself converted rotary to reclinear motion and was given power via the hydraulic works of Su's water clock tank and waterwheel, the latter which acted as a large gear.

Although chains can be made stronger than belts, their greater mass increases drive train inertia.

Toothed belt drives are designed to limit this issue by operating at a constant pitch radius[11]).

However, some newer synchronous belts claim to have "equivalent capacity to roller chain drives in the same width".

For this reason virtually all high-performance motorcycles use chain drive, with shaft-driven arrangements generally used for non-sporting machines.

[citation needed] A common design was using a differential located near the centre of the car, which then transferred drive to the rear axle via roller chains.

Frazer Nash were strong proponents of this system using one chain per gear selected by dog clutches.

[citation needed] Their chain drive system, (designed for the GN Cyclecar Company) was very effective, allowing for fast gear selections.