高速轴向柱塞泵柱塞腔空化机理研究

Study on Cavitation Mechanism in Piston of High-speed Axial Piston Pump

针对高速轴向柱塞泵内的空化问题,以某型号高速轴向柱塞泵为研究对象,搭建了其CFD数值仿真模型,研究柱塞泵旋转过程中的空化机理及演变规律。首先,对额定工况下柱塞泵的空化现象进行可视化分析,揭示空化的发生位置及在该位置处产生空化的机理;其次,以转速为变量,研究转速对空化的影响规律及其影响机理。结果表明:空化主要发生在柱塞腔内,充液率不足和流体漩涡影响是空化的主要原因;空化程度随着转速的升高而不断升高,这是由于流体流速的提高导致静压低,另一方面流体的离心力增大造成了充油率不足,同时还使流体进入柱塞腔的射流角增大;最后,根据空化机理对柱塞缸体底孔进行结构改进。在额定工况下,改进后柱塞腔内的空化程度与改进前相比下降了59.3%,空化抑制效果显著。

Aiming at the problem of cavitation in high-speed axial piston pump, CFD numerical model is established to study the cavitation mechanism and evolution law during rotation. Firstly, the cavitation phenomenon of piston pump under the rated working condition is visualized to reveal the location and mechanism of cavitation in the position. Secondly, the influence law and mechanism of speed on cavitation are studied with speed as variable. The results show that cavitation mainly occurs in the piston, and the insufficient filling rate and the influence of fluid vortex are the main reasons. The degree of cavitation increased with the increase of rotational speed, which is due to the increase of rotational speed leads to lower static pressure, higher centrifugal force and the larger jet angle of fluid. Finally, bottom structure of the piston cylinder block is improved. After the optimization, the degree of cavitation in the piston is reduced by 59.3%, and it has remarkable effect on cavitation suppression.