Crocodile Crusher Small Jaw Crusher High Calcium Jaw Crusher Output

Crocodile crusher small jaw crusher high calcium jaw crusher output

Frame welding inspection and reinforcement

As the skeleton of the jaw crusher, the frame will withstand the impact and vibration of materials for a long time, making its welds prone to cracks. In a sand and gravel plant in the south, during an inspection in June 2024, it was discovered that there was a PE-600×900 crusher with a small crack in the main weld in the lower part of the frame. The length of the crack was about 150 mm. It was not dealt with in time at that time. After two weeks of operation, the crack extended to 1,200 mm, causing the frame to deform. Eventually, the production line was forced to shut down for three days for emergency repairs, causing direct economic losses of more than 80,000 yuan.

During daily maintenance, you must regularly inspect all welded parts of the frame, focusing on the surroundings of the feed inlet, where the eccentric shaft bearing seat is fixed, and the welds connecting the bottom support ribs. Once a crack is found, it must be polished and cleaned immediately, and E5015 electrodes are used for repair welding. After welding, it needs to be cooled slowly to prevent secondary cracking. Most of the small jaw crusher frames are made of welded steel plates. It is recommended to conduct a comprehensive flaw detection every 3,000 hours of operation. The large cast steel frames should be inspected once a quarter, and any problems discovered and how they were dealt with should be recorded.

Jaw plate wear replacement standards

The consumable jaw plate is in direct contact with the material. The wear of the fixed jaw plate and the movable jaw plate directly affects the crushing efficiency and product quality. There is a stone factory in Shandong. Its operation data in 2024 shows that when the jaw plate tooth shape is worn to two-thirds of the original height, the output is reduced by about 18%, the power consumption is increased by 12%, and the finished grain shape is also significantly worse. After the factory promptly replaced the jaw plate in accordance with regulations, All indicators have returned to normal, and the production cost per ton of stone has been reduced by about 3 yuan.

When inspecting the jaw plate, you must use a caliper to measure the remaining thickness. Once the tooth tip wear exceeds 15 mm, you must consider replacing it. Before installing the new jaw plate, be sure to clean the surface of the jaw bed and check whether the fixing bolt holes are deformed. The bolts are made of grade 12.9 high-strength material and the torque must be tightened evenly. The contact surface between the jaw plate bead and the jaw plate must be smooth and close, and the wedge iron must be tight and not loose. Generally speaking, the service life of the fixed jaw plate is 4 to 6 months. Since the impact of the movable jaw plate is stronger, the service life is about 3 to 5 months. The specific situation depends on the hardness of the material and the feed size.

Eccentric shaft bearing lubrication and maintenance

The eccentric shaft is the core transmission component of the jaw crusher. The lubrication state of the bearing directly determines the operating life of the equipment. A return visit record from a mining machinery factory in Henan in 2024 shows that a customer's eccentric shaft bearing burned out due to poor lubrication. The repair cost was as high as 23,000 yuan, and production was resumed after 7 days of shutdown. Under the same working conditions, another piece of equipment strictly implemented the lubrication system and ran continuously for 18,000 hours, with the bearings intact.

Lubricating oil maintenance must meet such requirements. In the centralized lubrication system, the oil level and oil pressure must be checked once a week. Manual lubrication points must be filled with grease once every shift. The temperature of the babbitt bearing should not exceed 70 degrees Celsius under normal circumstances. It will feel hot when touched by hand, but it is suitable to stay there for a short time. In winter, use NLGI No. 2 lithium-based grease, and in summer, you can use NLGI No. 1 or 2. The lubrication pipeline must be cleaned every six months and all lubricating oil must be replaced. If the bearing gap exceeds 0.3 mm, it must be adjusted or replaced in time.

Maintenance of discharge port adjustment device

Among the adjustment devices that control the particle size of finished products, although the wedge-type adjustment structure is simple, it is prone to powder accumulation and stagnation. In Chengdu, Sichuan, there is a machine-made sand factory. Its production records in the spring of 2024 show that after the jaw crusher outlet of the factory was adjusted from the original 80 mm to 60 mm, the stone powder accumulated at the rear thrust plate support was not cleaned in time. After three months, the adjusting screw became rusty and could not move. It was eventually forced to stop and clean it before the normal adjustment function could be restored.

During daily use, the surface of the adjusting wedge should be cleaned of stone powder and impurities every week, especially the gasket gap between the rear thrust plate support and the frame. When adjusting the discharge port, both wedges must move synchronously to avoid deflection that would cause the movable jaw and the fixed jaw to become out of center. Carry out lubrication work on the adjusting screw and nut parts, and check whether the screw has bending deformation every quarter. When small equipment is adjusted by adding or removing gaskets, the gaskets must be combined in two specifications: 0.5 mm and 1 mm. After adjustment, the fixing bolts must be tightened to prevent loosening.

Flywheel balance detection and correction

The flywheel stores energy to keep the crusher running smoothly. If the balance is not optimal, it will cause severe vibrations in the equipment. There is a sand and gravel company in Chenzhou, Hunan. During an equipment inspection in August 2024, it was discovered that the vibration value of a PE-900×1200 jaw crusher reached 4.5 mm per second, which far exceeded the standard value of 2.5 mm per second. After some investigation, it was finally confirmed that three bolts on the pulley on the side of the flywheel were loose, and the balance weight was removed, causing the static balance to be destroyed. After tightening the bolts and adding a weight, the vibration returned to normal.

When performing flywheel maintenance, it is necessary to check the rim for cracks, especially the gate area of ​​the cast flywheel and the spoke roots. After disassembling and inspecting the flywheel and reassembling it, a static balance test must be performed. The allowable unbalance amount shall not exceed 200 g·mm. The mating surfaces of the pulley and flywheel need to be clean, and the keyway must fit tightly without looseness. The cylindrical runout of a flywheel in normal operation should be less than 0.5 mm. If it is found to exceed the standard, it must be corrected or replaced in time. Check the tightening torque of the flywheel fixing bolts every six months and tighten them diagonally twice to the specified value.

Lubrication pipeline system maintenance

The lubrication system of the jaw crusher is like its blood vessels. Only when the pipelines are kept unobstructed can reliable oil supply be ensured to each friction part. There is a cement factory in Huangshan, Anhui Province. When the raw material workshop equipment was overhauled in 2024, it was discovered that the oil return pipeline of the jaw crusher thin oil station was extremely blocked. A large amount of colloid sediments adhered to the inner wall of the oil pipe. It took two shifts to clean the oil return pipeline, and all aging sealing rings were replaced at the same time. If the fault is not discovered in time, it may cause the bearing to burn due to dry friction.

For daily maintenance of the lubrication system, the oil level in the oil tank should be checked every shift to ensure that it is within the marked range. The oil temperature cannot exceed 60 degrees Celsius, and the oil pressure needs to be stable between 0.15 and 0.3 MPa. Every 1,000 hours of operation, it is necessary to take samples to test the oil quality. If the acid value rises or the moisture exceeds the standard, the oil needs to be replaced in time. Pipe joints should be tightened once a month. Once oil leakage is found, seals should be replaced immediately. Clean the filter element every 500 hours and replace it with a new one every 2000 hours. Before starting in winter, the lubricating oil should be preheated to above 10 degrees Celsius before starting the machine to prevent poor lubrication caused by excessive viscosity.

Have you done regular riveting and welding maintenance on the small jaw crusher used in sand and gravel factories? Have you encountered similar types of failures with your related equipment? Welcome to the comment area to share your experiences and lessons learned!