In the roller quality inspection system, appearance and dimension inspection are fundamental links to ensure the roller’s adaptability, safety, and subsequent operational stability. These inspections must be strictly conducted in accordance with standards such as GB/T 10595-2023 Belt Conveyors. Even minor defects or deviations may lead to subsequent equipment failures.
Appearance inspection requires a comprehensive check for obvious defects in all components of the roller. For the roller tube, a combination of visual inspection and tactile assessment is necessary: the surface must be free of structural defects such as cracks, sand holes, and penetrating air holes. Such defects will cause uneven local stress on the conveyor belt, accelerate wear, and may even result in roller tube breakage in heavy-load scenarios like mines and ports. For welded roller tubes, the welds should be smooth and continuous, without issues such as weld beads, undercuts, or incomplete penetration. The edges of the welds can be touched by hand to ensure there are no raised burrs. If the roller tube is equipped with an anti-corrosion coating (e.g., galvanizing, plastic spraying), a coating thickness gauge should be used to measure the coating thickness, with the deviation controlled within ±10%. Meanwhile, the coating must be checked for no peeling, sagging, or bubbles to prevent the roller tube from being eroded in humid or corrosive environments.
Regarding the bearing housing and bracket: castings must be free of shrinkage holes, looseness, and cracks; stamped parts must have no obvious deformation; the height of burrs on the edges must be measured with a burr detector and ensured to be ≤ 0.2mm, so as to avoid scratching seals or operators during assembly. The surface of the shaft head should be smooth, without bumps, scratches, or rust; the threaded connection parts must be free of broken threads or thread slippage to ensure tight assembly.
Dimension accuracy inspection requires the use of precision instruments to control details. A digital caliper (with an accuracy of 0.01mm) is used to measure the total length of the roller, and the deviation must be ≤ ±0.5mm. Excessive deviation will make it impossible for the roller to match the conveyor frame accurately, leading to problems such as excessive gaps or failure to install after assembly. A micrometer (with an accuracy of 0.001mm) is used to measure the diameter of the roller tube, with the deviation ≤ ±0.3mm (for example, the actual measurement of a Φ89mm roller tube should be within the range of 88.7-89.3mm). Excessive diameter deviation will cause uneven contact area between the conveyor belt and the roller tube, intensifying local wear. The diameter of the shaft head at the part matching the bearing is inspected in accordance with the tolerance grade h6/h7 (for example, the actual measurement of a Φ20mm shaft head should be 19.987-20mm). An excessively loose fit may cause bearing slippage, while an excessively tight fit will lead to bearing overheating and jamming. A run-out tester paired with a dial indicator is used to inspect coaxiality, with the deviation per meter length ≤ 0.1mm. Excessive coaxiality deviation will generate centrifugal force when the roller rotates, causing conveyor vibration, noise, and shortening the service life of the equipment.
Although appearance and dimension inspection are basic links, they are the "first line of defense" for roller quality. Only by strictly controlling every indicator can a solid foundation be laid for the subsequent performance and safe operation of the roller.
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