Conveyor belt is the key equipment of the conveying system, and its safe and stable operation directly affects production operations. The deviation of the conveyor belt is the most common fault of the belt conveyor, and its timely and accurate handling is the guarantee of its safe and stable operation. There are many phenomena and causes of deviation, and different adjustment methods must be adopted according to different phenomena and reasons of deviation to effectively solve the problem. This article is based on years of field practice, starting from the user's point of view, using the principles of mechanics to analyze and explain the causes and treatment methods of such failures.
1. The axis of the head driving roller or the tail redirecting roller is not perpendicular to the center line of the conveyor, causing the conveyor belt to deviate at the head roller or tail redirecting roller. When the roller is skewed, the tightness of the conveyor belt on both sides of the roller is inconsistent, and the traction force Fq received along the width direction is also inconsistent, increasing or decreasing. This will add a moving force Fy to the decreasing direction of the conveyor belt. , Causing the conveyor belt to run to the loose side, that is, the so-called "run loose but not tight." The adjustment method is as follows: For the head roller such as the conveyor belt deviating to the right side of the roller, the bearing seat on the right side should move forward, and the conveyor belt deviating to the left side of the roller should be adjusted repeatedly until the conveyor belt is adjusted to the ideal s position. Before adjusting the drive or changing the direction of the roller, it is best to install its position accurately.
2. The outer surface of the drum is not uniform in diameter due to processing errors, sticky materials or uneven wear, and the conveyor belt will deviate to the larger diameter side. It is the so-called "run big but not run small". The traction force Fq of the conveyor belt produces a moving component force Fy to the larger diameter side. Under the action of the component force Fy, the conveyor belt deflects. For this situation, the solution is to clean up the sticky material on the surface of the drum. If there is processing error and uneven wear, it must be replaced and reprocessed.
3. The wrong position of the blanking position at the reloading point causes the conveyor belt to deviate. The blanking position of the material at the reloading point has a great influence on the conveyor belt's deviation, especially in the projection of the upper conveyor and this conveyor on the horizontal plane. The impact is greater when it is vertical. Generally, the relative height of the upper and lower belt conveyors at the transfer point should be considered. The lower the relative height, the greater the horizontal velocity component of the material, and the greater the lateral impact force Fc on the lower belt, and the material is also difficult to center. The material on the cross section of the conveyor belt is deflected, and the horizontal component Fy of the impact force Fc will eventually cause the belt to deviate. If the material deviates to the right, the belt deviates to the left, and vice versa. For the deviation in this case, the relative height of the two conveyors should be increased as much as possible during the design process. The form and size of the upper and lower funnels, guide troughs and other parts of belt conveyors that are restricted by space should be carefully considered. Generally, the width of the guide groove should be about three-fifths of the belt width. In order to reduce or avoid belt deviation, a baffle plate can be added to block the material, and the direction and position of the material can be changed.
4. The verticality error between the installation position of the supporting roller group and the center line of the conveyor is large, which causes the conveyor belt to deviate in the direction of the loading section. When the conveyor belt moves forward, a forward traction force Fq is given to the idler roller. This traction force is decomposed into a component force Fz that causes the idler roller to rotate and a transverse component force Fc. This horizontal component force causes the idler roller to move axially. The fixed roller of the bracket cannot move axially, it will inevitably produce a reaction force Fy on the conveyor belt, which causes the conveyor belt to move to the other side, which leads to deviation. After clarifying the force situation of the load-bearing roller set when the installation is skewed, it is not difficult to understand the reason for the deviation of the conveyor belt, and the adjustment method is also clear.
The first method is to process long holes on both sides of the roller set during manufacturing for adjustment.
The second method is to install a self-aligning roller set. There are many types of self-aligning roller sets, such as intermediate shaft type, four-link type, vertical roller type, etc. The principle is to block or block the rotation of the roller in the horizontal plane. Or generate lateral thrust to make the belt automatically centripetal to achieve the purpose of adjusting the belt deviation, and its force is the same as the deflection force of the load-bearing roller group. Generally, it is reasonable to use this method when the total length of the belt conveyor is short or when the belt conveyor is running in both directions. The reason is that the shorter belt conveyor is easier to deviate and is not easy to adjust. Long belt conveyors are best not to use this method, because the use of the self-aligning roller set will have a certain impact on the service life of the conveyor belt.
