According to different uses, chains can be divided into three categories: lifting chains, traction chains and transmission chains. The lifting chain is mainly used for lifting heavy objects in hoisting machinery, and its working speed is v≤0.25m / s; the traction chain is mainly used for moving heavy objects in chain conveyors, and its working speed is v≤4m / s; Movement and power are transmitted in general machinery, usually working speed v≤15m / s.
There are two types of transmission chain: toothed chain and roller chain. Toothed chain uses a specific toothed chain to mesh with a sprocket to achieve transmission, as shown in Figure 9-2. The toothed chain drive is stable and has low noise, so it is also called silent chain drive. The toothed chain allows a working speed of up to 40m / s, but it has high manufacturing cost and heavy weight, so it is mostly used in high-speed or high-accuracy applications.
There are two types of chains used in power transmission: sleeve roller chains and toothed chains. The sleeve roller chain is composed of an inner link plate, an outer link plate, a sleeve, a pin, and a roller. The outer chain plate is fixed on the pin and the inner chain plate is fixed on the sleeve. The roller and the sleeve and the sleeve and the pin can rotate relative to each other. Therefore, the meshing between the chain and the sprocket is mainly rolling friction. The sleeve roller chain can be used in a single row and multiple rows, and multiple rows can be used to transfer larger power. The sleeve roller chain is lighter in weight, longer in life and lower in cost than a toothed chain. It is widely used in power transmission.
Toothed chain is assembled by using pins to connect multiple pairs of chain pieces with 60 ° working surface. The working surface of the chain plate meshes with the sprocket. To prevent the chain from falling off the sprocket during work, the chain is equipped with an inner guide or an outer guide. When engaged, the guides fit into the corresponding guide grooves on the sprocket (Figure 1). Toothed chain transmission is smooth and has low noise, so it is also called silent chain, which is often used for high-speed transmission. The tooth profile of the sleeve roller chain and the toothed sprocket should ensure that the energy-saving chain can freely enter or exit the meshing, the impact is small when the meshing, and the contact is good when meshing.
