The chain is generally a metal link or ring, which is mostly used for mechanical transmission and traction. Chain-shaped objects used to obstruct traffic passages (such as at the entrance of streets, rivers or harbors), chains used for mechanical transmission.

1. The chain includes four series: transmission chain; conveyor chain; drag chain; special special chain.

2. A series of links or loops often made of metal: chain-shaped objects used to obstruct traffic passages (such as at the entrance of a street, river or harbor); a chain used for mechanical transmission.

3. Chains can be divided into short-pitch precision roller chains; short-pitch precision roller chains; curved plate roller chains for heavy-duty transmission; chains for cement machinery and plate chains; high-strength chains.

The structure of the transmission chain is composed of inner chain links and outer chain links. It is composed of five small parts: inner chain plate, outer chain plate, pin, sleeve and roller. The quality of the chain depends on the pin and sleeve.

In the transmission of machine tools, the commonly used transmission parts include pulleys, gears, worm gears, racks and pinions, and screw nuts. Through these transmission parts, the power source and the actuator, or the connection between the two actuators, is called the transmission connection. A series of sequential transmission elements forming a transmission connection is called a transmission chain.

The transmission chain usually contains two types of transmission mechanisms: one type is a transmission mechanism with a fixed transmission ratio and transmission direction, such as a fixed ratio gear pair, a worm turbine pair, etc., called a fixed ratio transmission mechanism; the other type is based on processing requirements The transmission mechanism that can change the transmission ratio and transmission direction, such as the change gear transmission mechanism, the sliding gear transmission mechanism, etc., is called the replacement mechanism.