Some things that are easily overlooked in the maintenance of diesel generator sets

I believe that many diesel generator set users have such doubts. I have done every maintenance and maintenance. Why do equipment still have frequent failures or have not had a long life? According to the summary of Haixing Dynamic's communication and interaction with customers over the years, this is actually largely related to everyone's misunderstanding of maintenance and neglecting some small details. In summary, it is just doing XXX and ignoring XXX. Let’s take a look at some of the things that are easily overlooked in maintenance and maintenance:

1. Only replace the plunger and oil nozzle, and ignore the technical status of the oil outlet valve. After the oil outlet valve is worn, the remaining pressure of the high-pressure oil pipe will be too high, causing the oil injector to be cut off and the oil dripped, causing smoke from the exhaust of the diesel engine, knocking on the cylinder, and unstable operation. The method is to check the oil outlet valve and use a pressure gauge of 0-600 kg/square centimeter to detect it. When the needle drops from 200 kg to 180 kg/square centimeter, the holding time should be greater than 15 seconds, otherwise the oil outlet valve should be replaced; or the high-pressure oil pipe port is pushed upward, and the diesel should be pumped out to make the oil surface flush with the pipe port, put the accelerator back to the stop supply position, and reverse the wheel for half a turn. The diesel at the high-pressure oil pipe port is qualified to not suction, otherwise the oil outlet valve should be replaced.

2. Only adjust the valve clearance and ignore the timing of the air distribution. Most people only adjust the valve clearance according to the specified values ​​in the instructions, but ignore checking whether the air distribution phase is timing. Especially for the elderly machine, due to changes in geometric shape after cam wear, the valve opens late and closes early, which will lead to insufficient intake, unclean exhaust, increased fuel consumption and reduced power. Therefore, when adjusting the valve gap of an elderly diesel engine, the valve gap value should be appropriately reduced according to the mechanism to make up for the error in the distribution phase. For example, for the S195 diesel engine, the valve clearance decreases by 0.1 mm, the gas distribution phase changes by 3 degrees. However, the valve clearance should not be less than 0.2 mm, otherwise it will be affected by expansion and will cause the valve to be closed tightly. If the valve clearance is already 0.2 mm, and the gas distribution phase still has an error of more than 5 degrees, and the working conditions of the diesel generator set are significantly deteriorated, the camshaft should be replaced.

3. Only look at the amount of oil in the oil pan and ignore the quality of the oil. Many people only replenish engine oil, never check the quality of the oil, nor replace it. Little do they know that the waste oil that should be replaced contains a large amount of oxidized substances and metal chips, which reduces the lubricating performance, aggravate the wear of the machine, and shortens its service life. Therefore, the quality of the engine oil in the machine should be checked at any time. The general method is to twist the oil by hand. If you feel that there are mechanical impurities or insufficient viscosity, you should replace it in time. Another method of inspection is to drop used engine oil on white paper. If the black dot is small and light in color, the yellow moist spots around it can continue to be used; if the dot is black and large and there is no yellow moist spots around it, it should be replaced.

4. Only know how to maintain air filters and ignore air short circuits. There are many reasons for air short circuit, such as the air inlet pipe of the air filter fixed to the tricycle frame is not welded properly, the gasket is not added at the junction of the air inlet pipe, the air inlet pipe is loose and clamped is not added, the air inlet hose is broken and the air inlet hose is not found, and the air inlet hose is missing is missing, etc. These will cause air short circuit, causing unfiltered air to enter the cylinder, aggravate the wear of cylinders, pistons, piston rings, valves and other components.

5. Only clean the oil filter and ignore the cleaning of the purified oil chamber. The connecting rod journal of most diesel generator sets is hollow and has oil blocked at both ends, which is called a purification chamber. Under the action of centrifugal force, the engine oil of the lubricating connecting rod bearing shells adheres to the cavity wall, thereby improving the lubricating quality. Generally, the oil blockage must be removed every 500 hours of working in the diesel generator set, and impurities in the oil chamber and oil passage should be purified according to the prescribed methods.