The vibrating screen is a key component of asphalt mixers, and its stable operation directly affects the efficiency and quality of asphalt mixture production. A tripping fault occurred in the vibrating screen of an M365 asphalt mixer during no-load operation, and the tripping phenomenon recurred immediately after restarting. This fault seriously interrupted the normal production process, so it is crucial to quickly locate the cause and implement effective troubleshooting. After the fault occurred, the maintenance team first carried out a comprehensive inspection of the electrical system. They replaced the new thermal relay, but the tripping fault still existed. Subsequently, they checked key electrical components and parameters including contactors, motor phase-to-phase resistance, grounding resistance, and phase-to-phase voltage, and no abnormalities were found. To further verify whether the electrical part was faulty, the maintenance personnel removed the transmission belt and started the vibrating screen independently. The ammeter showed a normal value of 10A, and no tripping occurred during 30 minutes of no-load operation. This result confirmed that the fault was not caused by the electrical system, and the problem should lie in the mechanical part of the vibrating screen. After reinstalling the transmission belt and restarting the vibrating screen, the maintenance team observed that the eccentric block of the vibrating screen vibrated more violently than usual, which became an important clue for fault location. To confirm the problem, the maintenance personnel removed the eccentric block and restarted the vibrating screen. At this time, the ammeter reading increased to 15A, which was significantly higher than the normal value, indicating that there was an abnormality in the mechanical transmission part related to the eccentric block. In order to accurately find the root cause of the fault, the maintenance team fixed a magnetic dial indicator on the vibrating screen box and used a stylus to check the radial runout of the shaft end. The measurement results showed that the maximum radial runout of the shaft end reached 3.5mm, which exceeded the normal range. Then, they disassembled the bearing of the vibrating screen for inspection and found that the maximum ellipticity of the inner diameter of the bearing was 0.32mm, which did not meet the technical requirements. The excessive radial runout of the shaft end and the elliptical deformation of the bearing inner diameter led to abnormal mechanical operation, increased load, and thus caused the tripping of the vibrating screen during operation. Based on the above inspection results, the maintenance team replaced the faulty vibrating screen bearing, reinstalled the eccentric block, and restarted the vibrating screen. After the maintenance, the ammeter indicated a normal value of 10A, and the tripping phenomenon no longer occurred. This case shows that for the tripping fault of the asphalt mixer vibrating screen, it is necessary to conduct a systematic inspection from both electrical and mechanical aspects, and accurately locate the fault point through targeted tests. Timely replacement of damaged mechanical components such as bearings can effectively ensure the stable operation of the vibrating screen, and then guarantee the continuous and efficient progress of asphalt mixing production.

Asphalt mixing plants are core equipment in road construction and maintenance, and their stable and efficient operation is inseparable from a series of matching accessory equipment. These accessory devices cover functions such as dust removal, material storage, grading, heating, recycling, and fuel processing, which not only ensure the quality of asphalt mixture production but also improve production efficiency, reduce environmental pollution, and meet the diverse needs of different construction scenarios. The following are the most commonly used accessory equipment for asphalt mixing plants and their core roles in the production process. Dust removal equipment is an essential part of asphalt mixing plants to meet environmental protection requirements, including bag dusting and water dust removal. Bag dusting equipment is widely used for its high dust removal efficiency. It captures and filters dust generated during the mixing and drying process in a dry state, effectively reducing dust emissions and avoiding air pollution. Water dust removal, on the other hand, uses water as the medium to absorb and settle dust, which is suitable for some specific working conditions and can also play a role in cooling while dedusting. Both types of dust removal equipment help asphalt mixing plants comply with environmental protection standards and create a cleaner production environment. Material storage and handling accessory equipment mainly include the finished material storage warehouse and asphalt bucket machine. The finished material storage warehouse is used to store the produced asphalt mixture, which can effectively keep the mixture at a suitable temperature and prevent it from caking or deteriorating, ensuring the continuity of subsequent construction operations. The asphalt bucket machine is a key device for asphalt transportation and feeding. It can accurately transport asphalt to the designated position in the mixing system, ensuring the stability and accuracy of asphalt supply, which is crucial for controlling the proportion of asphalt mixture and improving product quality. Grading and heating equipment, such as grading machine and fast-heating asphalt tank, play an important role in optimizing the performance of asphalt mixture. The grading machine is responsible for classifying aggregates according to particle size, ensuring that the aggregate gradation meets the design requirements of asphalt mixture, which directly affects the strength and durability of the final pavement. The fast-heating asphalt tank can quickly heat asphalt to the required temperature for mixing, improving the efficiency of asphalt melting and shortening the production cycle. It also has the function of heat preservation to avoid energy waste caused by repeated heating. With the promotion of green construction concepts, the asphalt recycled material crushing and screening system has become an increasingly important accessory equipment. This system can crush and screen waste asphalt pavement materials, process them into recyclable aggregates, and reuse them in the production of new asphalt mixture. This not only reduces the waste of resources and environmental pollution but also lowers the production cost of asphalt mixture, in line with the development trend of energy conservation and emission reduction in the construction industry. For asphalt mixing plants that use coal as fuel, coal crusher and coal mill are essential supporting equipment. The coal crusher crushes large pieces of coal into small particles of appropriate size, facilitating subsequent combustion and processing. The coal mill further grinds the crushed coal into fine powder, which can fully burn in the combustion system, improve fuel utilization efficiency, and reduce fuel consumption and pollutant emissions. These two devices ensure the stable supply and efficient utilization of fuel, providing reliable power support for the normal operation of asphalt mixing plants. In summary, the above nine types of accessory equipment are closely related to the entire production process of asphalt mixing plants. Each type of equipment undertakes unique functions and plays an irreplaceable role in improving production efficiency, ensuring product quality, and protecting the environment. Choosing suitable, high-quality accessory equipment is of great significance for the stable operation and long-term development of asphalt mixing plants, and is also an important guarantee for promoting the high-quality development of the road construction industry.