Telescopic belt conveyors are widely used as bulk material transportation machinery in terminals, power plants, metallurgy, grain and other industries. Some new users are not very familiar with the purchase, design, manufacture, installation and use of telescopic belt conveyor equipment. This article analyzes and explains the causes and treatment methods of common faults of telescopic belt conveyor equipment from the user's point of view. 1. Treatment of belt deviation of telescopic belt conveyor Belt running is the most common fault when the belt conveyor is running. Pay attention to the dimensional accuracy of the installation and daily maintenance. There are many reasons for deviation, and it needs to be treated differently according to different reasons. 1.1 Adjusting the telescopic belt conveyor carrying roller set When the entire belt conveyor is in the middle of the belt conveyor, the position of the roller group can be adjusted to adjust the deviation; during the manufacturing, the mounting holes on both sides of the roller group are processed to grow holes for adjustment. Which side of the belt is biased, which side of the roller set moves forward toward the belt advancement direction, or the other side moves backward. When the belt is deflected in the upward direction, the lower position of the roller set should move to the left, and the upper position of the idler set moves to the right. 1.2 Installation of the telescopic belt conveyor centering roller set There are many types of self-aligning roller sets, such as intermediate shaft type, four-bar type type, vertical roller type, etc., which are blocked or idled in the horizontal direction to block or generate lateral thrust to make the belt automatically adjust to the belt. the goal of. This method is generally reasonable when the total length of the belt conveyor is short or when the belt conveyor is operated in both directions, because the shorter belt conveyor is more prone to deviation and is not easy to adjust. 1.3 Adjusting the position of the drive roller and the reversing roller of the telescopic belt conveyor The adjustment of the driving roller and the redirecting roller is an important part of the belt deviation adjustment. Since a belt conveyor has at least 2 to 5 rollers, all drums must be installed at a position perpendicular to the centerline of the belt conveyor. If the deflection is too large, deviation will occur. The adjustment method is similar to the adjustment of the roller set. For the head roller, such as the belt, to the right side of the drum, the bearing housing on the right side should move forward, and the belt should be moved to the left side of the drum. The bearing housing on the left side should move forward, and the corresponding bearing can also Move the left bearing housing back or the right bearing housing back. 1.4 Adjustment of the tensioning belt conveyor tensioning The adjustment of the belt tension is a very important part of the belt conveyor's deviation adjustment. The two redirecting rollers on the upper part of the heavy hammer tensioning should be perpendicular to the vertical line of gravity in addition to the longitudinal direction of the belt, that is, the horizontal centerline of the shaft is ensured. 1.5 Influence of the blanking position at the transfer point of the telescopic belt conveyor on the deviation of the belt The blanking position of the material at the transfer point has a very large influence on the deviation of the belt, especially when the projection of the two belt conveyors in the horizontal plane is vertical. The relative heights of the upper and lower belt conveyors at the transfer point should normally be considered. The lower the relative height, the greater the horizontal velocity component of the material, and the greater the lateral impact on the lower belt, and the material is also difficult to center. The material on the cross section of the belt is deflected, which eventually causes the belt to run off. 1.6 Two-way operation of belt conveyor adjustment The adjustment of the deviation of the belt conveyor belt of the two-way operation is much more difficult than the adjustment of the deviation of the one-way belt conveyor. In the specific adjustment, one direction should be adjusted first, and then the other direction should be adjusted. When adjusting, carefully observe the relationship between the direction of belt movement and the trend of deviation, and adjust them one by one. 2. Spreading of the telescopic belt conveyor The spread of belt conveyors is a common problem, and the reasons are many. To strengthen daily maintenance and maintenance. 2.1. Spreading at the transfer point The material at the transfer point is mainly at the falling hopper, the guide trough, and the like. If the belt conveyor is seriously overloaded, the rubber skirt of the belt conveyor of the belt conveyor is damaged. The steel plate at the guide groove is designed to be longer than the rubber skirt of the belt to make the material rush out of the guide groove. 2.2. Spreading when the concave belt is suspended In the concave belt section, when the radius of curvature of the concave section is small, the belt will be suspended. At this time, the groove forming condition changes, because the belt has left the grooved roller set, and generally the groove angle becomes small, so that some materials are sprinkled. Therefore, a larger concave radius of curvature should be used as much as possible during the design phase to avoid such a situation. 2.3. Spreading when running off The material is deflected when the belt is deflected because the height of the two edges of the belt changes during operation, one side is high, and the other side is low, and the material is sprinkled from the lower side. The treatment method is to adjust the deviation of the belt. 3. Unusual noise of the telescopic belt conveyor When the belt conveyor is running, its driving device, drive roller and reversing roller, and the roller group will emit abnormal noise when it is not normal, and the malfunction of the device can be judged according to abnormal noise. 3.1. Noise when the roller is severely eccentric When the belt conveyor is running, the idler often has abnormal noise accompanied by periodic vibration. Especially for the return roller, because of its large length, it is self-important and the noise is relatively large. There are two main reasons for noise. First, the wall thickness of the seamless steel pipe for manufacturing the idler is uneven, and the centrifugal force generated is large. Second, during machining, the center of the bearing hole at both ends is greatly deviated from the center of the outer circle, so that the centrifugal force is too large. 3.2. Noise of the two shafts of the coupling without heart Abnormal noise at the coupling between the high-speed end motor of the drive unit and the reducer or the coupling with the brake wheel. This noise is also accompanied by the same vibration as the motor. When such noise occurs, the position of the motor reducer should be adjusted in time to avoid breakage of the input shaft of the reducer. 3.3. Abnormal noise of the reversing drum and the driving drum When the reversing drum and the driving drum work normally, the noise is very small. When abnormal noise occurs, the bearing is generally damaged, and the bearing housing is rattled. At this time, the bearing is replaced. 4. The shaft of the reducer The shaft of the telescopic belt conveyor reducer is generated on the high speed shaft of the reducer. The most common one is the high speed shaft of the vertical bevel gear shaft. There are two main reasons for a broken shaft. 4.1. The high speed shaft of the reducer is not strong enough. This situation generally occurs at the shoulder of the shaft. Because of the rounded corners here, it is prone to fatigue damage. If the round corner is too small, the reducer will break the shaft in a short time. The fracture after the broken shaft is usually flush. In this case, the gear unit should be replaced or the design of the gear unit should be modified. 4.2. High speed shafts are different When the motor shaft is not concentric with the high speed shaft of the reducer, the radial input of the input shaft of the reducer is increased, the bending moment on the shaft is increased, and the shaft breakage occurs during long-term operation. Carefully adjust the position during installation and maintenance to ensure that the two axes are concentric. In most cases, the motor shaft does not break. This is because the material of the motor shaft is generally 45 steel. The motor shaft is thicker and the stress concentration is better, so the motor shaft usually does not break. 4.3 Broken shaft in case of double motor drive The dual motor drive is equipped with two reducers and two motors on the same drive roller. When the high speed shaft of the reducer is designed or the margin is small, the shaft breakage is more likely to occur. In the past, the belt conveyor drive did not use a hydraulic coupling. This situation is more likely to occur because the speed synchronization and force balance of the two motors during start-up and operation are difficult to guarantee. Nowadays, most of the hydraulic couplings have been used to break the shaft, but the use of the coupling should not be too much, so that it can limit the torque and improve the life of the coupling. 5. The belt has a short service life The life of the belt and the condition of the belt are related to the quality of the belt. When the belt conveyor is running, the cleaner should be reliable and easy to use. There should be no material on the return belt. If the above contents are not guaranteed, the material on the return belt will enter the drive roller or the reverse roller with the return belt, and the belt will be damaged by the material and will damage the vulcanized rubber layer on the surface of the drum. A break will appear on the belt, reducing the life of the belt. The manufacturing quality of the belt is a concern of the user. After selecting a certain model, the quality of its manufacture should also be assessed. The state has a special quality appraisal agency to test it. It is customary to perform a visual inspection to see if there is cracking or aging, and whether the storage time after manufacture is too long. One of the above situations should not be procured. Belts that were initially found to be cracked tend to be damaged when used for a short period of time. 6. Influence of radius of curvature of convex and concave sections on belt conveyor 6.1. The middle section of the convex section belt is arched The convex section of the belt conveyor often takes place in the middle of the belt cross-section, and is convex in the middle. And the belt will be discounted, and the damage of the belt will be aggravated after entering the reversing drum or driving drum section after stacking. The main reason for arching and discounting is that the tensile force values ​​on the unit length of the middle and outer sides of the belt cross-section are too large, so that the belt slides to the middle to form an arch or a discount. The magnitude of the difference in tensile force per unit length is related to the radius of curvature of the segment and the angle of the idler groove. The larger the groove angle, the smaller the radius of curvature of the convex segment, and the more serious the arching and folding. When the groove angle of the belt conveyor reaches 40 degrees or more, the arching and folding can occur even in the transition section of the straight section of the belt conveyor straight section or the tail idler groove angle. In this case, the groove angle should be reduced or the length of the transition interval should be lengthened. The distance makes the belt groove angle slowly transition. For the convex belt conveyor, the radius of curvature of the convex section should be increased as much as possible and the angle of the idler groove should be reduced under the condition that the conveying capacity is satisfied. 6.2. The flange belt is caught between the flat roller and the skew roller The situation in which the belt is caught between the flat and skew rollers of the idler set generally occurs on the mobile bulk transporter. Such as ship loading machine, stacker and reclaimer. This type of device has a cantilever beam root position that tends to occur when the cantilever is lowered. At this time, it is equivalent to the convex section of the belt. Due to the limitation of the geometrical position, it is difficult to achieve the required size of the radius of curvature of the transitional projection. If the belt is located at the root of the cantilever, only one set of two sets of rollers is passed. When the projection is formed, a belt is caught between the flat roller and the skew roller of the roller set. The solution is to change the convex segments formed by the original two sets of roller sets here to four or five or more groups. 6.3. When the concave section starts, it bounces off and is blown off by the wind. If there is no material on the belt at the start of the belt conveyor, the belt will bounce in the concave section and the belt will be deflected when it encounters windy weather. Therefore, it is better to add a pressure roller to the concave section of the belt conveyor. Avoid bouncing the belt or being deflected by the wind. 7. Belt slipping 7.1. Heavy hammer tension belt conveyor belt slippage A belt conveyor that uses a weight tensioner can be added with a counterweight when the belt is slipping, added to the belt without slipping. 7.2. Spiral tension or hydraulic tensioning belt conveyor slippage When the belt conveyor using screw tension or hydraulic tensioning slips, the tension stroke can be adjusted to increase the tension.