The construction machinery industry has become an important pillar industry of China's national economic construction, and the reliability and stability of equipment operation are increasingly valued by people. Taking excavators as an example, according to relevant data statistics, about 50% of common failures occur in hydraulic systems, and 75% of hydraulic system failures are caused by problems with hydraulic oil cleanliness. Therefore, it is particularly important to summarize the impact of particulate matter pollution on the reliability of construction machinery, analyze the relevant reasons, and formulate corresponding countermeasures.

The reliability of hydraulic systems in construction machinery is closely related to the cleanliness of the hydraulic system. Particle pollution is a direct cause of affecting the cleanliness of hydraulic systems in construction machinery and can have a series of impacts on the reliability of construction machinery, mainly reflected in the following aspects:

1. Reduce the working efficiency of hydraulic pumps. The intrusion of particles of a certain size can cause wear and tear on hydraulic pumps, leading to an increase in leakage during operation and a decrease in output flow rate, pressure, and efficiency;

2. Affects the reliability of hydraulic cylinders. The intrusion of particulate matter can cause wear and tear on hydraulic cylinder seals under certain circumstances, and to a certain extent, it can lead to the failure of hydraulic cylinder seals, resulting in leakage of hydraulic oil inside and outside the hydraulic cylinder, ultimately reducing the reliability of hydraulic cylinder operation;

3. Reduce the reliability of hydraulic valves, causing malfunctions such as valve jamming and valve component control failure. Research has shown that particulate matter pollution can cause hysteresis in the operation of overflow valves, sticking or jamming of slide valve cores, reduced output stability and response speed of servo valves, decreased accuracy of proportional control characteristics of proportional valves, and even loss of control characteristics;

4. Accelerate the aging of hydraulic oil. The decrease in efficiency of hydraulic pumps can lead to an increase in the working temperature of hydraulic oil. The metal particles generated by the wear of hydraulic pumps and valve components will become catalysts for the oxidation of hydraulic oil at higher temperatures, accelerating the aging and deterioration of hydraulic oil;

5. Chain reaction causing wear of hydraulic components. After the particles in the hydraulic system cause wear and tear of hydraulic components, if not effectively controlled, the particles generated by wear will become new pollutants, and some abrasive particles may even become harder than their raw materials, leading to more severe wear and creating a vicious cycle.

Objectively carrying out the monitoring of particulate matter in hydraulic oil is a meticulous and challenging task, as many factors may affect the final detection results and cannot truly reflect the degree of particulate matter pollution in hydraulic systems. To ensure the objectivity of the test results, the following points should be noted:

1. Reduce the impact of sampling environment and sampling process on test results. When sampling hydraulic oil, special attention should be paid to the particulate matter and dust situation in the sampling environment. It is recommended to choose a relatively clean, windless, and dust-free environment for sampling. At the same time, when sampling, the oil outlet and its surroundings should be cleaned first to ensure that there are no particles, dust, or other substances that are easily detached.

2. Reduce the impact of sampling tools and container contamination on test results. For hydraulic oil used for cleanliness testing, the sampling tools and containers need to be sufficiently clean. After sampling, they should be immediately sealed and the sealing of the sampling container should be ensured.

The impact of particle pollution on the reliability of construction machinery is enormous. However, controlling particle pollution in hydraulic oil is a complex system that requires joint efforts from multiple dimensions, such as the manufacturing and selection of hydraulic components, the assembly of parts and the whole machine, and the use and maintenance of equipment, to ensure the cleanliness of the hydraulic system of construction machinery to the maximum extent possible and reduce the harm caused by particle pollution to the stable and reliable operation of construction machinery.