Basic type of chain drive:
According to different uses, the chain can be divided into three categories: lifting chain, traction chain and transmission chain.
The lifting chain is mainly used for lifting heavy objects in lifting machinery, and its working speed v≤0.25m/s; the traction chain is mainly used for moving heavy objects in the chain conveyor, and its working speed v≤4m/s; the transmission chain is used for General machinery transfers motion and power, usually working speed v≤15m/s. There are two types of transmission chains, toothed chains and roller chains.
The toothed chain is realized by the meshing of the chain plate of the specific tooth shape and the sprocket. The toothed chain transmission is stable and the noise is very small, so it is also called silent chain transmission. The allowable working speed of the toothed chain can reach 40m/s, but the manufacturing cost is high and the weight is large, so it is often used in the occasions where high speed or high motion accuracy are required. The chains used for power transmission mainly include sleeve roller chains and toothed chains.
Sleeve roller chain is composed of inner chain plate, outer chain plate, sleeve, pin shaft and roller. The outer chain plate is fixed on the pin shaft, and the inner chain plate is fixed on the sleeve. Both the roller and the sleeve and the sleeve and the pin shaft can rotate relatively. Therefore, the meshing of the chain and the sprocket is mainly rolling friction. Sleeve roller chains can be used in single row and multiple rows in parallel. Multiple rows can be used together to transfer larger power. The sleeve roller chain is lighter in weight, longer in life and lower in cost than the toothed chain. It is widely used in power transmission.
The toothed chain is assembled by using a pin to assemble multiple pairs of chains with a 60° working face. The working surface of the chain meshes with the sprocket. In order to prevent the chain from falling off the sprocket during work, the chain is equipped with inner or outer guides. When engaged, the guide piece is fitted with the corresponding guide groove on the sprocket. The toothed chain transmission is stable and the noise is very small, so it is also known as the silent chain and is often used for high-speed transmission. The tooth shape of the sleeve roller chain and the toothed chain sprocket should ensure that the energy-saving chain can freely enter or exit the meshing, the impact is small during the meshing, and the contact is good during the meshing.
The chain transmission is a transmission method that transmits the motion and power of the active sprocket with special tooth shape to the driven sprocket with special tooth shape through the chain. Chain transmission has many advantages. Compared with belt transmission, there is no elastic sliding and slipping phenomenon. The average transmission ratio is accurate, the work is reliable, and the efficiency is high. The transmission power is large, the overload capacity is strong, and the transmission size under the same working conditions is small. Low tightening force and low pressure on the shaft; can work in harsh environments such as high temperature, humidity, dust and pollution. The shortcomings of the chain drive are: only used for transmission between two parallel shafts; high cost, easy to wear, easy to extend, poor transmission stability, additional dynamic load, vibration, impact and noise will occur during operation, not suitable for rapid use In reverse transmission.
