The idler is an important part of the belt conveyor, with many types and large quantities. The function is to support the belt, reduce the running resistance of the belt, and make the verticality of the belt not exceed a certain limit to ensure the smooth operation of the belt.
The idlers are classified into self-aligning idlers, buffer idlers, troughing idlers, and parallel idlers according to their uses. The function of the self-aligning idler is to correct the deviation of the belt conveyor. Usually, a rotary groove-shaped self-aligning roller is installed on the heavy-duty section of the conveyor, and a parallel self-aligning roller is installed on the unloaded section. The buffer idler is applied to the tailstock according to the actual situation. When receiving the material, it can reduce the impact of the material on the belt, which is beneficial to the long service life of the belt. The grooved idler is generally composed of two side idlers and a flat idler, and the groove angle is generally 30 degrees. For a detachable belt conveyor, the three idlers of the slotted idler are hinged to each other, so It is called hinged idler. The parallel idler is generally a long roller, which is installed at the lower end under pressure, so it is called the lower idler.
The rollers are divided into steel rollers and plastic rollers in terms of material. The bearing seat of the idler has three types: cast iron, steel stamping and phenolic plastic.
The seal of the idler is divided into steel and plastic. Their seals are internally filled with grease. The quality of the idler directly affects the power consumption of the belt conveyor and the life of the belt. Therefore, reliable dustproof sealing and good lubrication are important usage criteria.
The idler accounts for 35% of the total cost of a belt conveyor and produces more than 70% of the resistance, so the quality of the idler is particularly important.
The influence of the radial runout of the idler on the belt conveyor: within the range of the runout specified by the state, the belt conveyor can be kept running smoothly, otherwise the belt of the belt conveyor will vibrate in resonance, causing material to be thrown, polluting the environment, and in the belt The higher the speed, the smaller the radial runout will be. The amount specified by my country's national standard is 0.7 mm, and the amount specified by the Japanese JIS standard is 0.5 mm.
The influence of the flexibility of the idler on the belt conveyor: During the operation of the belt conveyor, the flexibility of the idler is very important. If the flexibility of the idler is not good and the rotation resistance coefficient is high, the entire belt conveyor system will be affected. It has to pay more power, consume more power, and sometimes cause the tape to tear, the motor to burn out, and in more serious cases, it can cause a fire. Therefore, the selection of rollers with low rotation resistance coefficient (preferably lower than 0.020) is an important part of belt conveyor design and selection.
The influence of axial movement on the belt conveyor: my country's belt conveyor manufacturing technology is more and more advanced, but the axis movement is still a subject that needs to be studied, because my country's belt manufacturing technology and belt conveyor installation technology are still in line with the world's There is a big gap in the advanced countries, and the tape tends to deviate. If the axial movement of the idler is large, it will cause early damage to the idler. Generally, it is better to control the amount of axial movement within 0.5-0.7 mm.
There are also five criteria for judging the quality of idlers:
1. Dustproof performance of idler
2. Waterproof performance of idler
3. Axial bearing performance of idler
4. Roller impact resistance
5. Service life of idler