Temperature rise characteristics of oil film in flow distribution pair of high-pressure intra-vane type pump

With the development of vane pump toward high pressure direction, the requirement for the friction condition of its flow distribution pair is more stringent. The temperature rise of oil film in flow distribution pair which is composed by distribution plate and rotor will cause thermal deformation of flow distribution pair and affect the fitting clearance. Especially when the valid oil film cannot be formed by the flow distribution pair, the local temperature rise is more obvious, which will lead to the solid surface contact friction in the local area of the friction surface, and affect the normal operation of the vane pump. In order to improve the performance of high-pressure vane pump and the friction characteristics of the flow distribution pair, in this paper, the temperature rise of different parts of the oil film in the flow distribution pair was studied by means of theoretical analysis, numerical simulation and experimental test. For the convenience of analysis, the oil film was divided into six parts, which were shared out equally in the oil suction area and the oil discharge area. According to the flow state of the oil film in the flow distribution pair, the mathematical models of oil film temperature rise in the oil suction area and the oil discharge area were established respectively. The curves of temperature rise with working pressure in oil suction area and with sliding velocity in oil discharge area were obtained by calculation. The geometric model of the oil film was set up and meshed. Through the numerical calculation, the temperature distribution nephograms were obtained when pump working in the pressure of 3, 7 and 11 MPa. Finally, eight temperature sensors were installed at different radial and circumferential positions to measure the temperature of the oil film at eight acquisition points when the pump worked on three different pressures above. The actual temperature rise curve of the oil film of the flow distribution pair was obtained by subtracting the oil temperature rise data from the original data. The results showed that theoretical calculation, numerical simulation and experimental test results were close with small relative error. The temperature rise was affected by the working pressure and the thickness of the oil film, and it increased with the increase of pressure when the thickness of oil film was constant, while decreased with the increase of the thickness of oil film when the working pressure was constant. The temperature rise of oil film in the inner and outer layer of the oil suction area was different. And the temperature rise of oil film in the outer layers was 0.5 ℃ to 1 ℃, higher than that in the inner layer. The temperature rise of oil film in oil suction area was affected by both shear flow and differential pressure flow, while the temperature rise of oil film in oil discharge area was mainly affected by shear flow. Under the same working pressure, the temperature rise of oil film in oil suction area was 1.5 - 3.5 ℃, higher than that in oil discharge area. The temperature rise of the oil film in the outer layer of the oil discharge area was higher than that in the inner layer. The temperature rise of inner layer and outer layer oil film increases along the circumference from both sides to the center, and the largest temperature rise in the center position, with the difference being about 0.25 - 0.5 ℃. The research provides a reference for the oil film design of the flow distribution pair in high-pressure vane pump.