齿轮泵困油径向力的研究与量化分析

针对齿轮泵现有径向力计算的局限性问题，采用困油压力影响径向力的定量分析法，在1个困油周期内，先对从动轮齿顶圆上吸压、过渡、排压和困油的4区段内的动态液压分布，后基于实例困油压下的困油径向力进行研究和间接验证。结果表明：1）排压、吸压、过渡卸载下困油径向力的改善率分别为9.9%、-10.2%、-1.1%，困油压能改善排压卸载下的径向力，不过却恶化了吸压卸载下的径向力，对过渡卸载下径向力的影响不大，实际应用中，应尽量采用排压卸载的径向力减少措施；2）排压、吸压、过渡卸载下困油压力的冲击率分别为24.5%、38.5%和13.8%，对径向力的冲击很大，一方面要求通过卸荷槽创新尽量释放困油压力，另一方面应采用困油径向力的定量计算方法；3）困油压力对径向力的影响不仅在于本身更在于径向力的卸载措施，困油力由困油压力和作用面积共同决定，困油压、径向力、困油力的极值位置并非完全一致。困油径向力的定量计算方法为泵尤其是轴承的全流体润滑设计提供了动态的外载荷依据。

Research and quantitative analysis of the radial force impacted by trapped-oil pressure in external gear pumps

To overcome the limitations of current static calculation method of radial force without trapped-oil pressure in gear pumps, a new quantitative method for the influence of trapped-oil pressure on dynamic radial force was built. In a trapped-oil cycle, the dynamic fluid pressure distribution of four pressure sections, suction oil, transition oil pressure, discharge oil and trapped-oil pressure, on driven addendum circle were investigated, and the dynamic trapped-oil radial force were then studied and verified indirectly. The results showed that:The first improvement rate of new trapped-oil radial force to current radial force released differently by discharge oil, suction oil and transition oil was 9.9%, -10.2% and -1.1%, respectively. Then the radial force could be improved under relief by discharge oil. However, it was intensified under relief by suction oil and weakly impacted under relief by transition oil. Therefore, the relief by discharge oil was highly recommended in practice; The second impact rate of new trapped-oil radial force to current radial force released differently by discharge oil, suction oil and transition oil was 24.5%, 38.5% and 13.8%, respectively. The radial force was strongly impacted by trapped-oil pressure, so it was necessary to release trapped-oil pressure by innovated relief groove, and the new quantitative method was recommended to radial force calculation; The third effect of trapped-oil pressure on radial force was not only itself but also more other radial force relief measures. The trapped-oil force was collectively determined by trapped-oil pressure and its action area, so the extreme position of trapped-oil pressure, radial force and trapped-oil force was not completely consistent. In conclusion, the calculation results of the new quantitative method provided an accurate external load for full fluid lubrication design of bearings and other