No matter what we use, we hope that the products we buy are durable. The more durable, our consumers feel that they are worth the money, and the conveyor belt is the same. For conveyor belts, due to different conveyor belts, different fields of application and different materials to be transported, its impact on the conveyor belt is also different. Therefore, how to extend the service life of the conveyor belt and achieve the cost-saving effect is a matter worth studying. Today, I will tell you about several factors that determine the service life of conveyor belts:
One, the idler rolls into the groove angle:
The bearing branch usually adopts a trough-shaped roller group composed of three rollers, and the angle between the side roller and the middle roller is called the groove angle. Within a certain limit, the greater the groove angle, the greater the material flow. However, when the grooving angle exceeds the grooving capacity of the conveyor belt itself, the conveyor belt will not be close to the middle idler during no-load operation, resulting in strong wear on the edge of the conveyor belt and unstable operation; when operating under heavy load, the conveyor belt At the corners of the side roller and the middle roller, a large bending stress is bound to occur, causing the conveyor belt to break longitudinally or the canvas layer to peel off quickly.
Therefore, in the design, it is required that the roller groove angle must be consistent with the grooving capacity of the selected conveyor belt. This principle should also be observed when replacing the new conveyor belt in use. The groove angle of the idler is usually 30. When the conveyor belt has a good groove performance, it can be increased to 35.
2. Driving roller diameter:
When the conveyor belt goes around the roller, bending stress will be generated, causing the core fatigue. The smaller the diameter, the greater the bending stress. Obviously increasing the diameter of the roller is beneficial to improve the service life of the conveyor belt, but after increasing to a certain value, the bending stress will not decrease significantly, and the volume of the equipment will increase.
Therefore, in order to ensure that the bending stress of the conveyor belt is not too large, the minimum diameter of the roller should be limited.
The principle of selecting the diameter of the driving drum is:
1. When the multi-layer core conveyor belt adopts mechanical joints, D≥100i, mm (i is the number of canvas layers);
2. When vulcanized joints are used, since the joints are trapezoidal lap joints, they are easy to peel off under bending stress, so D≥125i, mm.
3. When the integrated core conveyor belt uses mechanical joints, D≥K8, mm (k depends on the parameters of the core frame material; 8 is the core thickness, mm).
4. When steel rope core conveyor belt is used, D=(150～200)(t, mm (d is the diameter of steel rope, mm).
5. The diameter of the reversing roller is determined according to the conditions of the driving roller diameter, the force percentage and the wrapping angle of the conveyor belt to the roller.
3. Convex arc radius:
When there is a convex arc on the conveyor line, there is also a great tensile stress on the edge of the conveyor belt when it passes, causing the conveyor belt and the roller to be prematurely damaged, so the radius of the convex arc should not be too small. When using steel cord conveyor belt, the radius of the convex arc should not be less than (75～85)B.
Four. Over distance:
The section of the conveyor belt between the head and tail rollers of the conveyor and the first set of supporting rollers is called the transition section. In the transition section, the conveyor belt changes from groove shape to parallel or from parallel to groove shape, and the edge of the conveyor belt is stretched to generate additional tensile stress. The smaller the length of the transition section, the greater the additional tensile stress, which will cause serious wear on the edge of the conveyor belt and the side rollers, which will cause the conveyor belt to fatigue prematurely and even cause the edge of the conveyor belt to break.
In order to make the edge of the conveyor belt partially stretch not to exceed the elongation rate of the conveyor belt, the length of the transition section should not be too small. For the fiber core conveyor belt, the transition section length is taken as 1.3 times the distance between the idlers;
Since the allowable elongation rate of the steel cord conveyor belt is 0.2%, the transition section length is calculated according to the formula L≥2.67cc B, where B is the bandwidth
D is the groove angle of the idler, rad. If the L value is much larger than the distance between the supporting rollers, several transition roller groups should be installed between the roller and the first group of supporting rollers to prevent the belt from sagging and sprinkling.
