齿轮泵齿侧间隙与卸荷槽间距关系的定量分析

Quantitative analysis of relationship between backlash value and distance of two relief grooves in external gear pump

为探索在一定的容积效率和最大限度缓解困油现象的前提下,齿轮泵无侧隙时的最小卸荷槽间距是否适用于有侧隙情况,该文在主要考虑困油的齿侧间隙泄漏和卸荷槽槽口泄漏的基础上,通过前期所建立且被验证的困油模型,对齿侧间隙泄漏量、槽口泄漏量及两者的泄漏容积率进行仿真计算,给出了2种泄漏容积率针对不同的齿侧间隙值、转速和出口压力的变化曲线。结果表明,现有针对有、无侧隙的判别式过于苛刻;侧隙越大、出口压力越高时,容积效率越低,困油现象越轻;转速越高时,容积效率越高,困油现象越严重;无侧隙时的最小卸荷槽间距极大地改善了困油现象,容积效率得以提高,较大侧隙下仍可采用小侧隙下的卸荷槽间距。研究结果可为齿轮泵的卸荷槽布置提供一种新的参考。

For meeting higher volumetric efficiency and minimizing pressure of trapped oil in external gear pump, the topic that whether the minimum distance between two relief grooves in small backlash could be applied in a large backlash or couldn’t be proposed. Based on only considering two main leakages produced from the gap between backlash gap and relieving grooves, through trapped oil model created and verified in the early literature, two main leakages and it’s volumetric ratios were calculated by simulation, and the curves of two volumetric ratios were respectively generated with different backlash values or speeds or output pressures. All the results indicated that the determination of no backlash or a backlash in external gear pump was meaningless. The volumetric efficiency was decreased with the increasing of the backlash value and output pressure. The trapped-oil phenomenon was more seriou with higher rotate speed and volumetric efficiency. The minimum distance between two relieving grooves in no backlash made trapped-oil phenomenon to be greatly improved, and the improvement made the volumetric efficiency higher. Finally, the minimum distance between the two relieving grooves in a small backlash can be applied in a large backlash, which provides a new reference in layout of relieving grooves for external gear pump.