When the shift lever is operated integrally, the pressure oil can reach the corresponding hydraulic cylinder and loader parts through the control valve. Push the piston clamp and actively push the block to obtain transmission power. In actual use, often waiting for maintenance machines not working, this loss is a good repair time and shortens the life of the transmission. This paper analyzes the cause of power shift clutch damage, introduces a method of measuring clutch piston seal and transmission failure prevention measures to improve the service life of power transmission.
1, the cause of clutch failure
The power shift clutch is engaged, and the hydraulic oil pressure spring compacts the friction plate. As the pressure of the hydraulic oil increases, the friction lining gradually contacts the metal plate and the pressure, so that the clutch flywheel power is smoothly transmitted to the transmission input shaft. Each time the steel is rubbed and rubbed, the heat generated by the coolant is dispersed. When the steel friction plates become thinner, more hydraulic oil is needed to make them fully combined, the engine is further accelerated, the sliding time of the steel plate friction plates is extended, and the resulting friction heat increases the temperature when the hydraulic oil is sufficient. The temperature at which the transmission sealing performance changes, and internal propagation causes leakage. Internal leakage causes heat to increase in two ways. High-pressure damaged seals leak oil and the oil temperature continues to rise. Due to the oil, the hydraulic pump will inevitably bring more oil to ensure the required pressure. When the clutch is engaged and the clutch is fully engaged, it also needs to continue to accelerate the engine, which generates more flow. The vicious cycle will eventually cause the clutch to overheat or burn until it fails completely.
2, clutch piston seal detection
When the loader is walking or the oil temperature is too high, it is necessary to ensure that the clutch piston seal is not tight or the oil pressure is low, but the traditional detection method is sometimes difficult to determine the failure. The reason, especially in the absence of electricity, is that it is more difficult to inspect the gearbox assembly of the assembled seal.
At this time, the pneumatic valve can be used for testing. First, the transmission control valve (assembling the transmission should be in front of the loading control valve), and sequentially transfer the oil hole 0.6 0.8 MPa gas to leave the factory. If there is gas leaving the factory, the first time you hear "explosion" there is no air or intake metering pump, piston and The small program between the cylinders and the well-matched clutch. If you hear the sound of the piston friction block and the air, the seal between the clutch piston and the cylinder fails. The seal should be replaced.
3, transmission failure prevention
Power transmission drive bearings and gears are fragile parts, so they should be regularly inspected and maintained for transmission. The typical overseas transmission maintenance interval is 5000 5000 h. According to the situation in China, it is recommended to check the clutch wear every 2,500 5,000 h and catch abnormal signals at any time. Due to the failure of the power transmission drive, the wear debris of the friction plate cannot be changed quickly, and it can usually continue to be used for 750-1000 hours for the first time. During this period, regular inspection and maintenance, timely replacement of friction plates, seals and single bearings can avoid undamaged parts (such as steel, gears, shafts, hydraulic cylinders and most bearings, etc.).
The following abnormal conditions often occur before the clutch failure
(L), the machine can still work, the transmission oil has deteriorated, the viscosity has dropped and the metal impurities, so it should be recommended to change the oil interval more frequently. Sampling analysis before transmission. Because the wear of the clutch is an indication of the expansion of the gear box, if the metal impurities of the gear or the gear make it impossible, if he does not close it will destroy other workpieces.
(2) The decrease in transmission performance is a sign of damage. The clutch slips. Even if the acceleration is smooth, the machine will move forward, and it should be stopped at this time.
(3) When the machine must accelerate the clutch engagement, the clutch working oil level drops, which means that the clutch has been excessively worn or sealed. Therefore, measuring the gearbox oil pressure and observing the increase in oil temperature can determine clutch wear.
If iron or chromium particles are in the oil, the oil should also be analyzed to show that the gears have begun to wear.
In short, if the seal replacement fails, the maintenance cost of the friction clutch will be less than 30% and then the clutch failure is repaired. Similarly, if the grounding or gear failure is repaired, the cost is completely damaged. 2/3 of the maintenance drive
