Types and hazards of lubricating oil contamination of excavator

Contaminants in lubricating oil include various substances mixed in the working medium that are harmful to the surface life of internal combustion engine parts, such as solid particles, water, exhaust gas, diesel (gasoline) oil and polluting energy.

1) Solid particles. Solid particle pollutants are the most common type of pollutants in lubrication systems. It includes the remaining metal chips that are not cleaned during the processing and assembly of the parts, the dust and debris that intrudes into the system from the outside during the mechanical driving (or construction), the wear debris and erosion flakes generated on the surface of the parts, and the oil oxidation And the sediment produced by decomposition. These solid particles mixed in the lubricating oil penetrate into the mating surfaces of the moving parts like abrasives, accelerating the surface wear of the parts (such as Swing Ring Gear, planetary gear carrier assembly, Travel Reduction Gearbox, Sun Gear,etc), greatly shortening its use life.

2) Water. When water is immersed in the lubricating oil, the lubricating oil becomes milky white and rapidly oxidizes and deteriorates. Not only loses lubrication, but also corrodes the metal surface.

3) Exhaust gas. During the operation of the internal combustion engine, there is always a certain amount of high temperature and high pressure exhaust gas from the combustion chamber into the crankcase. The exhaust gas contains water vapor and SO2. Water vapor condenses in the engine oil to form bubbles, which disrupts the normal oil supply. This phenomenon is particularly serious in winter; SO2 meets water to generate H2SO3, and H2SO3 meets O2 to generate H2SO4, which will corrode mechanical parts.

4) Diesel (gasoline) oil. The lubricating oil mixed with diesel (gasoline) oil will make the lubricating oil thinner, lower the viscosity, and increase leakage. The surface of the moving pair cannot form a thick enough oil film, and the lubrication effect is prematurely lost.

5) Pollution energy. Pollution energy refers to the thermal energy of lubricating oil. If the oil temperature is too low, the lubricating oil has high viscosity, poor fluidity, and it is difficult for the oil pump to absorb oil, and at the same time it makes it difficult to start the internal combustion engine; Dry friction can even oxidize, decompose and deteriorate the lubricating oil.