According to different purposes, 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 the lifting machinery, and its working speed is v≤0.25m/s; the traction chain is mainly used for moving heavy objects in the chain conveyor, and its working speed is v≤4m/s; the transmission chain is used for Generally, the motion and power are transmitted in the machine, and the working speed is usually v≤15m/s.
The drive chain has two types of toothed chains and roller chains. The toothed chain is driven by the engagement of a specific toothed chain and a sprocket, as shown in Figure 9-2. The toothed chain transmission is stable and the noise is very small, so it is also called the silent chain transmission. The toothed chain allows a working speed of up to 40 m/s, but it is expensive to manufacture and heavy, so it is often used in applications where high speed or motion accuracy is required.
The chains used for power transmission mainly include sleeve roller chains and toothed chains. The sleeve roller chain is composed of an inner chain plate, an outer chain plate, a sleeve, a pin shaft and a roller. The outer chain plate is fixed on the pin shaft, the inner chain plate is fixed on the sleeve, and the roller and the sleeve and the sleeve and the pin shaft are relatively rotatable, so that the meshing of the chain and the sprocket is mainly rolling friction. Sleeve roller chains can be used in a single column and in multiple columns. Multiple columns can be used to transfer large 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 a combination of a plurality of pairs of working faces having a 60° angle with a pin. The working face of the chain engages the sprocket. In order to prevent the chain from falling off the sprocket during operation, the chain is provided with an inner guide or an outer guide. When engaged, the guide piece is engaged with the corresponding guide groove on the sprocket (Fig. 1). The toothed chain transmission is stable and the noise is very small, so it is also known as the silent chain, which is often used for high speed transmission. The tooth profile of the sleeve roller chain and the toothed chain sprocket should ensure that the chain is energy-saving free to enter or exit the engagement, the impact is small when engaged, and the contact is good when engaged.
