Hydraulic gear pump is widely used in hydraulic drive system. Because of its characteristics of high pressure, strong resistance to pollution and low price, hydraulic gear pump is widely used in various hydraulic systems such as construction machinery and construction machinery. Gear pump run in the factory during the trial run, because of the phenomenon of brooming, inevitably produce pollutants, these pollutants will be directly contaminated hydraulic test system, and due to the current test bed oil pollution control technology and means of conventional restrictions, pollution The material will also contaminate the gear pump itself by the oil remaining in the gear pump to reduce the reliability of the hydraulic system of the gear pump. Therefore, the research on the oil purification technology of the gear pump test stand has gained universal attention in the system industry. Hydraulic gear pump factory test-bed oil pollution status: According to industry standards, gear pump test-bed oil contamination level shall not exceed IS04406-19 / 16, equivalent to NAS1638-10 level. In order to find out the status quo of gear pump test bed hydraulic oil pollution, in 2006 we chose to gear pump industry with large-scale and representative Shandong Runuang Hydraulic Technology Co., Ltd. (now Haldex (Qingzhou) Co., Ltd.) as a test point , And the test bed oil sampling, analysis and tracking test. The results show that the company gear pump test bed oil cleanliness NASl638-13 level, the pollution has been quite serious. Oil particle size distribution in the 10-30μm range accounted for more than 80%, we can see that during the test, due to the broom phenomenon generated by conventional oil filter filter, the particle size of pollutants Mainly distributed in the range of 10-30μm, and because the pump body is mostly aluminum alloy and other metal materials, particle contaminants in the suspension in the oil state, with the frequency of test bed increases and the passage of time, oil cleanliness Deterioration, the physical properties of the oil also dropped sharply, the test results become worse, the residual oil in the pump body is also hidden trouble for future use. In the past, the company took the measure of frequent replacement of the test bed oil and after the test gear pump secondary cleaning, a great waste of human and financial resources. The problem of oil pollution is a big problem that plagued the development of the company and has caused widespread attention in the industry. Test-bed oil pollution control, through analysis and comparison, we agreed that: due to the structure of the gear pump, the phenomenon of the broom during the test is inevitable, only from the test system to clean up equipment to fundamentally solve the oil Of the pollution problems, but also requires purification equipment must accommodate dirt capacity, high filtration accuracy. To this end, we recommend introducing the German KLEENOIL ultrafiltration device next to the tank. The device filter media consists of long fibers with polypropylene, which has high particle retardation and dehydration ability. Fine particles above 1μm can be filtered while water is locked in the core assembly. Oil additives will not be filtered by the filter, by filtering and control pollution, oil additives can be preserved catalysis. Purified oil back to the tank into the next cycle, after the cycle, the oil cleanliness fully meet the test requirements. Germany KLEENOIL (Ke Reynolds) ultrafiltration device with high filtration accuracy, dirt capacity, a filter can accommodate impurities 2500g, water 780ml. Multi-cycle filter can remove more than 1μm particles, and there is no plug problem, long service life, low maintenance costs and so on. KLEENOIL (Correno) through a separate oil sample test to determine the replacement of the filter and the number of lubricating oil or hydraulic oil. Practice has proved that the application of Germany KLEENOIL (Ke Renuo) ultrafiltration device, the service life of lubricating oil or hydraulic oil can extend the original 5 to 10 times. In the gear pump production process, with the improvement of single-piece cleaning process, the pollution condition between the gear pump production process can be greatly improved, but the phenomenon of swallowing during the test running-in process is inevitable, and the fluid extracorporeal circulation filtration System and Germany KLEENOIL (Correno) ultrafiltration device combined with the application, effectively solve the test-bed oil purification problems, to eliminate hidden dangers and improve product quality and lay the foundation. At present, Hydraulics (Qingzhou) Co., Ltd. hydraulic gear pump factory experimental platform to design their own extracorporeal circulation filtration system, and the use of Germany KLEENOIL (Correno) ultrafiltration device, oil pollution has been effectively controlled, hydraulic gear pump product clean Degree by major OEMs at home and abroad recognized.