Loader gearbox shift mechanism damaged repair and maintenance

Loader power shift transmission hydraulic pressure multi-piece wet clutch shift gear shift, each gear from 2-5 friction plates and the corresponding pressure plate, hydraulic cylinder and other components. When manipulating the gear lever in a gear, the pressure oil flows into the corresponding hydraulic cylinder through the control valve to push the piston to compress the driving plate and the driven plate, so as to achieve the purpose of transmitting power. In actual use, often wait until the machine does not work properly when maintenance, resulting in the loss of the best time to repair and shorten the life of the transmission. In this paper, the reasons for the clutch damage of the power shift transmission are analyzed. A method to detect the clutch piston sealing and the measures to prevent the transmission failure are introduced to improve the service life of the power shift transmission. 1 . Causes of clutch damage Power shift transmission When the clutch is engaged, the pressure of the hydraulic oil compresses the friction plate against the spring force. As the pressure of the hydraulic oil increases, the friction plate comes into contact with the metal plate and gradually compresses so that the clutch transmits the power of the flywheel smoothly to the transmission input shaft. Each shift, the friction plate and the steel friction occurs, the heat generated by the coolant is emitted. When the friction plates and the steel sheet become thinner, more hydraulic oil is needed to fully engage them, the engine needs to be further accelerated, the friction time of the friction plate on the steel plate also increases, and the resulting frictional heat More, prompting the hydraulic oil temperature increases, when sufficient to change the performance of the transmission seal temperature, the transmission will have internal leakage. The internal leakage and from two aspects continue to cause increased heat: high-pressure oil leaks through the damaged seal, so that the oil temperature continues to rise; due to oil spills, the hydraulic pump potential delivery of more oil to ensure the engagement clutch The pressure required to fully engage the clutch also requires the engine to continue accelerating to produce greater flow to the hydraulic pump. Such a vicious cycle will eventually lead to clutch overheating or burning until it completely fails. 2 . Clutch Piston Sealing Test When the loader is running weak or the oil temperature is too high, it is necessary to determine whether the clutch piston is not tightly sealed or under-pressured. However, it is sometimes difficult to determine the cause of the conventional test. This is especially so in the case of In the absence of power, it is more difficult to inspect the seal rings of the assembled transmission assembly. At this point, the pressure valve can be used for testing. First of all, remove the transmission control valve (before the assembled transmission should be installed with the control valve), then turn on the 0.6-0.8mpa gas to each oil hole of the transmission. If one of the holes passes through the gas,嘭 "and no sound leakage or leakage is very small, then the corresponding seal between the clutch piston and the cylinder well; if you can not hear the piston compression of the friction plate and a large leak sound, Then the clutch piston and cylinder seal between the failure, the seal should be replaced. 3. Prevention of Transmission Failure Transmission and transmission gearbox bearings and gear are vulnerable parts, so the transmission should be regularly checked and serviced. Foreign typical transmission maintenance interval is 5000 a 10000h. According to China's national conditions, it is recommended that every 2500 a 5000h that should check the clutch wear and tear, and catch anomalies at any time. Due to the power shift transmission can not be quickly failed, wear debris in the friction plate for the first time, usually can continue to use 750-1000h. During this period, regular inspection and maintenance, and the timely replacement of friction plates, seals and individual bearings, can be undamaged parts (such as steel, gears, shafts, hydraulic cylinders and most of the bearing, etc.) damage. Clutches tend to have the following abnormalities before they fail: (1) Although the machine can still work, the oil in the transmission has long been deteriorated, viscosity has been reduced, and metal impurities have been contained and should therefore be analyzed more frequently than before the recommended oil change intervals Transmission oil sample. Because the clutch wear and tear is a sign of the expansion of the transmission failure, if the metal impurities into the gear or stuck gear so that it can not be in the center, and if no downtime will smash the other components in the transmission. (2) shift performance degradation is a sign of clutch damage. When the clutch starts to slip, the machine will rush forward even if it accelerates smoothly. At this time, it should be shut down for maintenance. (3) Clutch control oil level drops, when the machine must accelerate to make the clutch engaged, it shows that the clutch has been excessive wear or seal failure phenomenon. Therefore, measuring the transmission oil pressure and observe the oil temperature rise can determine the clutch wear and tear. At the same time should also analyze the oil, if the oil appears in iron or chromium particles, it shows that the gear pair has begun to wear. To sum up, if the seals and friction plates are replaced before the clutch fails, the maintenance costs will be 30% lower than after a clutch failure. Similarly, if the service is done before the planetary gear or gear pair fails, the cost is two-thirds lower than when a completely damaged transmission is being repaired.