Thread Content
After operating for a long time, belt conveyors inevitably cause certain wear and damage to their conveying components. It is necessary to carry out appropriate maintenance on these conveying devices to ensure they meet the required quality standards, thereby bringing better economic benefits to manufacturing enterprises. When repairing the truss of belt conveyor components, it is necessary to remove the conveyor belt, place the truss on a flat surface, and carry out the repairs section by section. The reinforced supplementary steel members should be of the same type; welding must be secure, and after repair, they should be straightened and leveled. The truss must be free of cracks and deformations, and it must not experience abnormal vibrations or displacements during operation. If the belt clip connection has cracked, cut off 150 to 200 millimeters from each end of the old belt at that connection point, and replace it with a new belt segment of the desired length. The belt should be replaced when its wear exceeds 40% to 50% of its thickness, or when the rubber layer of the belt has severely peeled off. Small belt connectors use circular or flat hooks for joining belts, with belt clamps selected according to the belt size. During assembly, it is necessary to ensure that the clip is perpendicular to the center line of the belt; the ends of the belt buckle must not extend beyond the edge of the belt, with a distance of 5 to 8 millimeters from the edge being appropriate. It is not allowed to use the drum as a base for leveling. For large and medium-sized belts that are joined by screws or cover plates aligned with each other, M10 countersunk bolts are used. The connecting bolts must be secure and not loose; any protruding parts after tightening must be sawed off. The cover plates must make tight contact with the belt’s surface, and their sharp edges must penetrate into the belt. When large and medium-sized belts are overlapped in a stepped manner, the overlap length is approximately 1.5 times the belt width; the cutting angle is 20 degrees, the spacing between each step is 200 millimeters, and the overlapping areas must be vulcanized. When large and medium-sized belts are joined using layered overlapping, the overlapping angle can range from 30 to 45 degrees; the overlapping seams should intersect at different layers, and the joints need to be vulcanized. Drums and idlers (excluding motorized drums): Drums and idlers must rotate smoothly, and the connection between the drive drum and the drive shaft must be firm and secure, with no looseness allowed. The straightness error at both axis ends is less than 0.5 millimeters. The surface of the metal drum and its spokes must be free of cracks or severe defects; otherwise, they should be repaired or replaced. The ellipticity of the drum shall not exceed one percent of the drum diameter. The belt thickness at the metal drum should be replaced if the wear exceeds 60 percent. Rubber or plastic drums and idlers should be replaced when the outer belt surface is worn by 40 to 50 percent, or when the drum expands at both ends, causing the bearings to loosen or come loose from the drum. When installing the idler rollers, the idler roller frame must be perpendicular to the longitudinal center line of the truss. To check this, a straight line can be drawn along the center lines at both ends of the truss, and then a right-angled ruler can be used for verification. Direction-changing load-bearing idlers must not be ordinary flat idlers or deformed idlers; the diameter of such idlers must be at least 219 millimeters. The shaft and journal should be free from defects such as damage or cracks, and the surface finish of the journal should be at least 7. The straightness of the shaft shall not exceed half of the journal tolerance specification; otherwise, it should be straightened or replaced. The bearing should rotate smoothly without any noise; there should be no pitting, rust, or delamination on the surfaces of the balls or rollers as well as on the inner and outer rings. If such conditions exist, the bearing should be replaced. Measure the bearing clearance with a dial indicator. The contact angle between the shaft and the bearing shell should be in the range of 60 to 90 degrees at the bottom, and there should be no less than 2 imprint points per square centimeter of contact area. Bearing alloys should be free from defects such as cracks, flaking, heavy scaling, and sand holes. Exposed drive gears: The tooth surfaces should be smooth, free of burrs and cracks. The dimensions meet the requirements of the drawings. If the tooth thickness wear exceeds one-quarter, it should be replaced. The contact length of the tooth thickness shall not be less than 40 percent of the total tooth width, and the contact height shall be 30 percent of the total tooth height. When gears are in mesh, the tooth tip clearance should be within the range of 0.2 times. Before installing the gear, clean the gear and the shaft first, apply a thin layer of oil on the shaft, and install it evenly using specialized tools; the fit should be of type H7/M6 or H7/K6. During assembly, the gear and key must not get stuck to each other to avoid misalignment. The safety guard or casing of the exposed gear drive mechanism is in good condition. Belt cleaner: Adjust the cleaning scraper tip so that the rubber makes firm contact with the belt surface, but without applying excessive pressure. When the rubber belt of the cleaning scraper wears down to a distance of 5–10 millimeters between the metal frame and the surface of the belt, it is necessary to adjust the flip plate and replace the rubber belt, in order to prevent the metal clamps from coming into contact with the metal frame of the cleaning scraper, which could damage the belt clamps or even tear the belt. A rubber baffle must be installed between the feed hopper and the belt to prevent scratches or jamming of the belt. The repaired or newly manufactured hoppers should be free from welding deformation; quality must be ensured, and their installation height should be appropriate and secure. Special tools should be used for the disassembly and repair of couplings; striking them may cause damage.