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The primary issue with idler rollers during use is their operational problems. The sluggish rolling behavior of the idlers, or even the complete absence of rolling in severe cases, causes the resistance coefficient associated with their operation to change from that of rolling to that of sliding; this value increases by about 10 times. As a result, the operating resistance rises, power consumption increases, and accordingly, the conveying distance or volume handled by the belt conveyor decreases ； Secondly, due to the inflexible rolling of the idlers, wear on the idlers and conveyor belt increases, reducing their service life. The decrease in the service life of idlers necessitates frequent replacement of these idlers, resulting in a severe shortage of idler spare parts. This increases the workload associated with the maintenance of conveyor equipment, thereby raising transportation costs. 1. Quality analysis of idler rollers and process development: There are many factors that affect the operational efficiency and service life of idler rollers, including the structure of the rollers, the quality of their manufacturing, sealing and lubrication systems, as well as maintenance practices. The structure of an idler roller mainly consists of pipes, bearing housings, bearings, seals, lubricant, and shafts. The impact of each of these main components on the quality of the idler roller is analyzed as follows: (1) Pipes. The manufacturing quality of pipe fittings is an important factor affecting the quality of idlers; their own out-of-roundness and misalignment during processing directly influence the radial runout and rotational resistance of the idlers, ultimately affecting their service life. Therefore, to improve the quality of idler rollers, we use high-frequency welded pipes of better quality, as well as machine tools for drilling holes at both ends of the steel pipes. By using the chamfered ends of the pipes as a reference, we drill the inner hole ends at both sides, thereby ensuring the required dimensions and precision of the pipe bodies and avoiding quality issues that can arise due to misalignment of the pipe ends. (2) Bearing housing. The DTⅡ type idler is a idler with a stamped bearing seat; experience has shown that a bearing seat made by stamping 3mm thick steel plate provides high strength, and it is easy to ensure the installation accuracy and operational flexibility of the idler. The precision of the bearing seat’s surface also has a direct impact on the quality of the idler rollers. To ensure the dimensions of the internal hole after stamping as well as its coaxiality with the outer diameter, we used high-quality sheet materials and specialized die materials for the manufacturing process. Using the bearing area as a reference point, CO2 gas shielded welding was employed to weld the bearing seat to the tube body. This approach not only meets the required three-level precision standards for the internal hole, ensuring that the rotational resistance and radial runout of the idler roller remain within acceptable limits, but it also **reduces the overall weight of the idler roller**. (3) Bearings. The service life of a idler roller primarily depends on the performance of its bearings and seals; if the idler roller has good sealing properties, its service life is essentially equivalent to that of its bearings. Bearings not only have a significant impact on the service life of idler rollers, but also exert a certain influence on the rotational resistance of these rollers. The test results show that the frictional resistance of the bearing accounts for 1/4 to 1/8 of the rotational resistance of the idler roller. The primary causes of roller bearing failure are as follows: ① A large amount of coal dust or sludge enters the bearing, filling the bearing channels and the holes in the retainer with sludge, preventing it from rotating and thus leading to failure ； ②When the grease in the bearing is lost, a large amount of external water or moisture penetrates in, causing severe rusting of the steel cage, steel balls, and the internal and external channels, which prevents it from rotating and renders it ineffective. Oil degradation can also cause bearings to fail ； ③Failure caused by the poor quality of the bearing itself ； ④Poor quality of the device after machining leads to bearing failure. To address this issue, we replaced the idler roller bearings with 305KA bearings designed for large clearance. Test data show that even under extremely harsh operating conditions, the service life of these specialized bearings is **longer than that of ordinary bearings, and their rotational resistance is more than half lower. (4) Smooth lipids. The common lubricating greases used for idlers in coal mines today are calcium-based greases and lithium-based greases suitable for mining use. Calcium-based greases have good water resistance, but they have a low melting point; they tend to solidify at high temperatures. After being used for some time, they easily change color and dry out, becoming unsuitable for further use, which in turn affects the service life of the bearings. In addition to possessing the main advantages of calcium-based greases, mining lithium-based greases have strong resistance to hydrolysis and good mechanical stability. They are suitable for use in environments with temperatures ranging from -20 to 120°C, and can cope with the harsh working conditions in coal mines, such as constant exposure to coal dust and moisture. Therefore, it is essential to use lithium-based lubricants to improve the lubrication conditions of idler bearings, in order to extend their service life. (5) Axis. The machining quality of the shaft is another important factor affecting the quality of the idler roller; its own out-of-roundness will directly influence the radial runout and rotational resistance of the idler roller, ultimately affecting its service life. Therefore, we adopted a one-time machining method using pins at both ends of the shaft, and grinding was employed to ensure the shaft’s dimensions and precision requirements, thereby avoiding quality issues caused by shaft misalignment in the idlers. 2. Quality requirements for the idler roller device and measures to ensure compliance with these requirements: (1) Inspection – ① Parts (including those purchased from external suppliers) must meet the requirements specified in the drawings after passing inspection ； ②It is necessary to thoroughly clean the bearing housings of the roller bodies, ensuring that no debris remains. (2) Apply lubricant: ① Fill the recessed area inside the seal with lithium-based mineral lubricant ； ②The same lubricating grease fills 2/3 of the space inside the bearing ； ③The internal and external seals are filled with mining-grade lithium-based lubricant in their respective 1/2-cavity spaces, while the cavity between the sealing disc and the inner retainer is also filled with mining-grade lithium-based lubricant ； ④The recess of the outer retaining ring is filled with a mining-grade lithium-based lubricant that occupies 2/3 of the cavity. (3) Press-fitting ① Press the seal ring together with the bearing into the bearing housing. Note that when using KA series bearings with a large clearance designed for idler rollers, the installation direction of the bearing must be such that the nylon retainer faces outward (toward the shaft end). After the bearing is installed in the idler roller body, an appropriate clearance must be maintained; it must not be compressed too tightly ； ②Gently press the inner seal into the bearing housing until it makes contact with the outer ring of the bearing, then stop applying pressure. Check the condition of the grease; if it has been squeezed out by the pressing head, smooth grease should be added ； ③Press the inner and outer retaining rings into the bearing housing one after another, applying gentle pressure until they come into contact with the inner seal ring, then stop pressing immediately ； ④After the idler roller installation is complete, it is necessary to check whether the rotation is smooth and to inspect the gap between the adjusting baffle and the retaining ring. During the full press-fitting process, the seals must not be damaged or have any bent edges; the inner and outer seals must not be installed together. By formulating the production processes for standard idlers and establishing and improving quality control methods, the product quality of these idlers has seen significant improvement. As conveyor systems evolve towards longer distances, higher capacities, and greater speeds, the requirements for idlers become increasingly stringent. Only by continuously improving manufacturing processes and optimizing product design can high-quality idlers be produced, thereby meeting the speed requirements of large-scale belt conveyor systems.