齿轮泵困油的分析模型及侧隙计算

Analysis model on trapped oil and backlash calculation in external gear pump

为解决外啮合齿轮泵侧隙的现有选用方法误差较大的问题,在分析齿侧间隙组合卸荷槽对缓解困油压力的影响及对侧隙要求的基础上,通过困油容积及其变化率和困油区内卸荷槽口和侧隙处的两种主要泄漏量计算,根据困油的体积弹性模量,建立了困油分析的简易模型,并由困油压力最大峰值的仿真计算,给出了侧隙的精确计算方法,最后就工况参数的影响结果与现有文献的试验结果进行对比分析.结果表明:所建立的困油模型和侧隙计算方法是可靠的,在侧隙计算中可以忽略困油中含气的影响,出口压力对侧隙计算的影响不大,但是转速的影响较大.在最小卸荷槽间距配小侧隙和最大卸荷槽间距配大侧隙的两种卸荷组合中,应优先采用最小卸荷槽间距配小侧隙的卸荷组合.侧隙的精确计算为外啮合齿轮泵的设计提供了一种新的方法,具有一定的工程应用价值.

In order to resolve bigger errors in the current method applied to calculate backlash in external gear pumps,based on analyzing the impact of backlash and relief groove on trapped oil pressure and required backlash,by the calculation of trapped volume and change rate of trapped volume and two major leakage rates from trapped oil area through opening of relief groove and gap of backlash,a simple analysis model on trapped oil was established.By simulation of the maximum peak of trapped pressure,the accurate calculation method was given to determine the reasonable backlash,and all results of backlash affected by working parameters were compared with that tested from existed literature.The results show that the established trapped oil model and calculated backlash are reliable,the effect of the air mixed in trapped oil and the outlet pressure on the select of backlash value can be ignored,but the rotate speed of pump has a greater effect on the select of backlash,in both combinations of narrow space distance of two relief grooves with small backlash and wide space distance of two relief grooves with small backlash,the former combination should be used preferentially.The accurate calculation of backlash value is proved to be a viable option for the design of the external gear pump.