Basic type of chain drive:
According to different uses, chains 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 to move heavy objects in the chain conveyor, and its working speed v ≤ 4m / S; The transmission chain is used to transmit motion and power in general machinery, and the working speed is usually V ≤ 15m / s. There are two kinds of transmission chains: toothed chain and roller chain.
The toothed chain is driven by meshing the chain piece of specific tooth shape with 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 toothed chain can reach 40m / s, but it has high manufacturing cost and heavy weight, so it is mostly used in occasions with high speed or high motion accuracy requirements. There are mainly two kinds of chains for power transmission: sleeve roller chain and toothed chain.
The 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. The roller and the sleeve and the sleeve and the pin shaft can rotate relatively. Therefore, the meshing between the chain and the sprocket is mainly rolling friction. The sleeve roller chain can be used in a single row or in combination with multiple rows, which can transfer large power. The sleeve roller chain has the advantages of light weight, long service life and low cost. It is widely used in power transmission.
The toothed chain is composed of a plurality of pairs of chain pieces with 60 ° working face with pin shaft. The working surface of the chain piece is meshed with the sprocket. In order to prevent the chain from falling off from the sprocket during operation, the chain is equipped with an inner guide plate or an outer guide plate. When engaged, the guide plate is embedded with the corresponding guide groove on the sprocket. Toothed chain has stable transmission and low noise, so it is also known as silent chain and is often used for high-speed transmission. The tooth shape of sleeve roller chain and toothed chain sprocket shall ensure that the chain can enter or exit the meshing freely, with little impact during meshing and good contact during meshing.
Chain transmission is a transmission mode that transmits the motion and power of the driving sprocket with special tooth shape to the driven sprocket with special tooth shape through the chain. Compared with belt drive, chain drive has many advantages, such as no elastic sliding and slipping, accurate average transmission ratio, reliable operation and high efficiency; Large transmission power, strong overload capacity and small transmission size under the same working conditions; The required tension is small and the pressure acting on the shaft is small; It can work in harsh environments such as high temperature, humidity, dust and pollution. The main disadvantages of chain drive are: it can only be used for the transmission between two parallel shafts; High cost, easy wear, easy elongation, poor transmission stability, additional dynamic load, vibration, impact and noise will be generated during operation, so it is not suitable for rapid reverse transmission.