轴向柱塞泵功率密度影响因素分析

为进一步提高轴向柱塞泵功率密度,首先结合前人工作针对功率密度给出量化计算公式,并对其中最重要的2个因素进行了研究。分析表明,影响因素1单位体积的每转排量主要由斜盘倾角与柱塞分布圆半径决定,并提出采用柱塞包覆滑靴形式提高该因素值,计算表明其柱塞泵功率密度可提高60%;影响因素2最高转速主要受自吸性能影响,且普通柱塞泵自吸性能受缸体腰型槽粘性阻力与强制漩涡阻力影响,并随着转速提高而下降,对此提出一种双向倾斜式腰型槽缸体,其仿真证明该结构具有离心甩油作用,其最高转速最高可提高45.4%。最后针对大排量双联泵功率密度下降问题提出了一种对称X型高功率密度轴向柱塞泵结构,其功率密度提高了43%。

Analysis of Factors Influencing Power Density for Axial-piston Pump

In order to further increase the power density for axial-piston pump, the quantitative formulas were derived and the most important factors were studied. One factor was the amount of volumetric displacement of pump per revolution divided by the spatial volume of pump, and the analysis indicated that it was determined by swash plate angle and piston pitch-radius, and 60% increase of it could be obtained by using an inverted piston-slipper design. The other factor was the maximal speed which was determined by the self-priming ability (SPA) of pump. The analysis result showed that the SPA was affected by resistance caused by viscous resistance and forced vortex, and the ability dropped with the rotating speed increasing, which was the defect of current structure of cylinder block. In order to overcome the defect, a new structure of cylinder block with bidirectional inclined cylinder block hole was presented, and the results of simulation demonstrated that SPA of axial-piston pump was increased by 45.4%. Finally, to meet the requirement of large displacement pump, a symmetrical X shape axial-piston pump was proposed and its power density was verified theoretically. The analysis result showed that the power density was increased by 43% compared with a double-pump.