The idler is one of the key components that affect the use effect of the conveyor, accounting for about 30%~40% of the weight of the whole machine and 5%~30% of the price of the whole machine. In belt conveyors, idlers are used to support the conveyor belt and the load, and to ensure that the sag of the conveyor belt is within the design limits. In the design of belt conveyor, the selection and quantity of pallets have an important impact on the normal use, stable operation, maintenance cost, power consumption and price of the belt conveyor.
Due to the special position of belt conveyors in the field of transportation, the research on conveyor idlers is becoming more and more important. Now, the research and analysis of the roller is mainly the internal structure of the roller and the shape structure of the roller, and has achieved good research results, so that the roller in the internal structure to achieve reasonable structure, good sealing, reliable operation, durable, in the shape and structure to achieve good contact with the tape, protection to prevent deviation, increase the amount of conveying and other effects. In addition, the material used in the tray is also an important part of the design. Nowadays, new materials are increasing, and there are more and more materials for manufacturing rollers, so it is necessary to choose reasonable materials to make the rollers achieve better performance. In order to ensure the working efficiency of the conveyor and reduce the cost, it is necessary to carry out reasonable structural design and processing and manufacturing methods for the support.
Depending on the type of belt conveyor, the idlers can be divided into different types. Specific to a belt conveyor, in terms of structure, the idler is divided into the upper idler and the lower idler. The number of upper rollers is generally 3-4, and the types include automatic ordinary rollers, self-aligning rollers and buffer rollers. The number of brackets is generally 1-2, and the main types are cleaning belt idlers and ordinary idlers. With the technological development of belt conveyor, the research on new types of pallets has also been paid attention to, and some new products with unique structure and excellent performance have emerged. The following is a brief introduction to (1) flexible idlers
Flexible idlers refer to those with flexible properties, good contact and protection of the tape during operation. In terms of working performance, it can increase the capacity of the conveyor and improve the inclination angle of the conveyor. It is generally used in the general transportation industry. Flexible idlers can be divided into the following types according to the different materials they are made of:
1) Parabolic idlers. The roller shaft of this roller unit is a flexible mandrel that allows the belt to sag naturally into a parabolic shape. It mainly includes two long and short rolling elements, a flexible mandrel and a connecting device. On the mandrel, long and short cylindrical rolling elements are installed in a certain distribution and are able to rotate.
2) Spring-loaded idlers. The structure mainly consists of cylindrical coil springs and suspension mechanisms. When the spring is working, it is naturally concave and in line contact with the tape, which plays the role of supporting the tape and the load, and its biggest feature is that it can effectively solve the problem of tape deviation.
3) Adjustable spring idlers. This type of roller consists of a cylindrical coil spring, a hanging device and an adjustment device. The coil spring is installed alternately according to the left and right rotations, and the preload can be applied through the coupling shaft, which can control the sag amplitude of the spring, so that it can realize the functions of automatic self-alignment and prevent the tape from mistracking.
4) Flexible spiral idler. It is composed of a bracket, a spiral roller, a flexible shaft and a bearing seat. Structurally, the helical shaft is not subjected to loads, so there is no deformation and failure, and the spiral parameters are independent of the glue width and load.
5) Wire rope core idler. It is composed of steel wire rope mandrel, rubber roller body, slewing mechanism, etc. The flexible steel wire rope mandrel is formed by the mandrel and the steel wire, and the concave-convex grooved rubber roller body and the steel wire rope mandrel form a whole. In addition, there is a slewing mechanism. It is generally suitable for mines, ports and other transportation fields.
