Hydraulic gear pumps are commonly used power components in hydraulic transmission systems. Due to their high pressure, strong pollution resistance, and low price, they are widely used in various hydraulic systems such as construction machinery and construction machinery. During the running-in process of the gear pump in the factory test, due to the phenomenon of sweeping the bore, pollutants will inevitably be generated. These pollutants will directly pollute the hydraulic test system. Moreover, due to the limitations of the conventional control technology and means of oil pollution on the test bench, pollution Substances will also contaminate the gear pump itself through the oil remaining in the gear pump, and reduce the reliability of the gear pump hydraulic system. Therefore, the research on the oil purification technology of the gear pump test bench has received general attention in the system industry.
The current status of oil pollution degree of the hydraulic gear pump test bench: According to industry standards, the pollution degree of the oil used in the gear pump test bench shall not be higher than IS04406-19/16, which is equivalent to NAS1638-10. In order to find out the pollution status of the hydraulic oil of the gear pump test bench, we sampled, analyzed and tracked the test bench oil in 2006. The measurement results show that the oil cleanliness of the gear pump test bench is NASl638-13, and the pollution has been quite serious. The particle size distribution in the oil is more than 80% in the range of 10-30μm. It can be seen that in the test process, the pollutants generated by the sweeping phenomenon are filtered by the conventional oil filter, and the pollutant particle size Mainly distributed in the range of 10-30μm, and because the pump body is mostly aluminum alloy and other metal materials, particulate pollutants are suspended in the oil. With the increase in the frequency of use of the test bench and the passage of time, the cleanliness of the oil With the continuous deterioration, the physical properties of the oil have also dropped sharply, and the test results have become worse. The contaminated oil remaining in the pump body will also bury hidden dangers for future failures. In the past, the company's measures were to frequently replace the test bench oil and clean the gear pump after the test, which greatly wasted manpower and financial resources. The problem of oil pollution is a major problem that plagues the development of the company, and has attracted widespread attention in the industry.
Oil pollution control on the test bench. Through analysis and comparison, we agree that: due to the structure of the gear pump, the sweeping phenomenon during the test is inevitable. Only by starting from the purification equipment of the test system can the oil be fundamentally solved. In addition, the purification equipment must have large pollution holding capacity and high filtration accuracy. For this reason, we recommend ultra-fine filtration devices. The filter medium of the device is composed of long fibers with polypropylene. It has high particle delay and dehydration ability. Fine particles above 1 μm can be filtered, and water is locked in the core component. The additives in the oil will not be filtered by the filter element. Through filtering and pollution control, the catalysis of the additives in the oil can be preserved. The purified oil returns to the oil tank to enter the next cycle. After the cycle, the cleanliness of the oil fully meets the test requirements.
In the gear pump production process, with the improvement of the single-piece cleaning process, the pollution situation between the gear pump production processes can be greatly improved, but the sweeping phenomenon in the test running-in process is inevitable, and the oil and liquid are filtered outside the cycle. The combined application of the system and the ultra-micro filter device effectively solves the problem of oil purification in the test bench, laying a foundation for eliminating hidden troubles and improving product quality.