What are the advantages of synchronous belts compared to chain drives

To understand the advantages of synchronous belts and chain drives, it is necessary to first have an understanding of both. Synchronous belt drives are generally composed of driving wheels, driven wheels, and transmission belts tightly fitted to the two wheels. By utilizing intermediate flexible components, rotational motion and power are transmitted between the main and driven shafts through friction. The synchronous belt is made of steel wire as the tensile body, wrapped with polyurethane or rubber. A circular transmission belt with a rectangular cross-section and equidistant transverse teeth on the surface, and the synchronous belt wheel surface is also made into corresponding tooth shapes. The transmission is achieved through the meshing between the synchronous belt teeth and the synchronous belt wheel teeth, without relative sliding between the two, and the circumferential speed is synchronized, hence it is called synchronous belt transmission. Chain drive consists of a sprocket and a circular chain, and the meshing between the chain and sprocket teeth is achieved through the same direction transmission between parallel axes. Compared with belt drive, chain wheel drive has no elastic sliding and slipping, can maintain accurate average transmission ratio, requires less tension, and exerts less pressure on the shaft, which can reduce friction loss of bearings. It has a compact structure and can work in harsh environments such as high temperatures and oil stains; Compared with gear transmission, its manufacturing and installation accuracy is lower, and its transmission structure is simpler when the center distance is larger.

Synchronous belt transmission is composed of a closed circular tape with equidistant teeth on the inner surface and a pulley with corresponding teeth. During operation, the convex teeth of the belt mesh with the groove of the pulley to transmit motion and power. Compared with other transmission ratios, synchronous belt transmission has the following advantages. When working, there is no sliding and accurate transmission ratio. Synchronous belt transmission is a type of meshing transmission. Although the synchronous belt is an elastic body, the load-bearing rope in it has the characteristic of not extending under tension, so it can maintain the belt pitch unchanged, so that the belt can correctly mesh with the gear groove, achieve synchronous transmission without slip, and obtain accurate transmission ratio.

Synchronous belt
Smooth operation, able to absorb vibrations;
No need for lubrication, oil and water resistance, high temperature resistance, corrosion resistance, convenient maintenance and upkeep;
Smooth transmission, with buffering and vibration reduction capabilities, and low noise;
High transmission efficiency, up to 0.98, with significant energy-saving effect;
Convenient maintenance, no need for lubrication, and low maintenance costs;
The speed ratio range is large, usually up to 10, and the linear speed can reach 50m/s, with a large power transmission range of several watts to several hundred kilowatts;
Can be used for long-distance transmission, with a center distance of over 10m.
Strict center distance requirements and high installation accuracy are required;
The manufacturing process is complex and the cost is high.

Chain drive
Advantages:
① Accurate average transmission ratio;
② Chain transmission does not require a large initial tension, and the pressure on the shaft is small;
③ High transmission efficiency;
④ High carrying capacity
⑤ Capable of long-distance transmission;
⑥ Low cost.

Disadvantages:
① Instantaneous transmission ratio is not constant;
② There are certain dynamic loads and impacts in the transmission, and the transmission is unstable;
③ There is noise during transmission.
The general range applicable to chain transmission is: transmission ratio: i ≤ 8, power P ≤ 100KW, chain speed V ≤ 12-15m/s, transmission efficiency is 0.95-0.98.