The idler is used to support the tape and with the movement of the tape for rotary motion of the components, the role of the idler is to support the tape, reduce the movement resistance of the tape, so that the tape sag does not exceed the specified limit, to ensure the smooth operation of the tape. According to the material of the idler, most of the idlers are made of seamless steel pipes. In recent years, newly developed ceramic idlers and nylon idlers are mainly used before and after the iron remover.

Classification of idlers
According to its different uses, can be divided into: groove roller, parallel roller, buffer roller and aligning roller four kinds.

trough idler
It is mainly used on the load branch of the belt conveyor, generally composed of 2 to 5, and its number is determined by the bandwidth and groove angle. The angle between the outermost roller and the horizontal line is called the roller angle. After the roller groove angle is increased (within the range of 0 ° ~ 60 °), the material accumulation section is increased, which can improve the production capacity and prevent the scattering, deviation and improve the conveying inclination. The groove angle of TD62 series groove support stick is generally 20 °, and TD62 type changes the groove angle to 30 °, which can increase the conveying capacity of adhesive tape by about 20% and make the cargo load run smoothly.

The roller body is generally made of seamless steel pipe, and the main problem of seamless steel pipe is the large deviation of size and geometry. The bearing seat of the roller is made of cast iron type, steel plate stamping type and phenolic plastic cloth. The lubrication of the roller is mostly lithium-based grease, and the second lithium-based grease is generally used. Most of the reasons for the damage of the roller is not good sealing, dust into the bearing and stuck. Roller bearing seal is generally used labyrinth seal, sealing materials are nylon 6 and 1010 two.

parallel idler
It is mainly used as the lower roller of the column load branch to support the belt of the empty section of the conveyor belt. It is generally a long roller with the same structure as the short roller. There are two kinds of common steel structure roller and rubber ring roller.

1. The characteristics of ordinary steel structure roller: the rotating part is heavy and easy to stick coal.
2. The characteristics of the rubber ring roller: the rotating part is light in weight, stable operation and less coal sticking.

Buffer idler
In fact, it is also a groove-shaped idler, which is used on the carrier roller of the loaded branch of the belt conveyor to protect the adhesive tape and prevent the carrier roller bearing from being damaged by impact. It is generally installed in the guide trough section. Buffer roller is divided into two kinds of rubber ring type and spring plate type. Rubber ring type buffer roller, that is, the groove roller three short roller outside the rubber ring, to achieve the purpose of buffering. The spring plate buffer roller only changes the support frame of the three-section short roller into a spring plate, and the elastic deformation of the spring plate support frame can play a buffering role.

aligning roller
The function is to adjust the longitudinal center line of the conveyor belt to make it coincide with the center line of the conveyor, so as to prevent and reduce the wear and torsion caused by the deflection of the belt during transportation, as well as the scattering of transported materials. The self-aligning idlers installed on the belt conveyor and the groove idlers with load branches include: one-way rotating automatic aligning idlers, forward-tilting groove-shaped aligning idlers, reversible automatic aligning idlers and conical automatic aligning idlers. Under no-load branch, the idlers are: parallel automatic aligning idlers and V-shaped forward-tilting return idlers.

When the belt conveyor is running, the following factors may cause the belt to deviate: uneven distribution of tension along the bandwidth, eccentric accumulation of materials, deformation of the frame, damage to the roller bearing, wind load, etc. Any of the above factors will cause the running belt to run off, so various forms of belt conveyors inevitably have different degrees of running off. In order to reduce this problem, in addition to the installation, maintenance and operation of the adjustment, but also should be installed a certain number of self-aligning roller. Usually every ten sets of self-aligning rollers are installed.