摘要
为探求建立齿轮泵最小困油压力解析式以克服试验和仿真上的局限性,分大、小侧隙2种情况,针对困油的膨胀阶段,采用细长孔的流量公式计算侧隙内的压差流量,在对困油的轴向泄漏路径做适当简化后,由困油区内的"困油容积的膨胀率=泄漏量",即困油压力变化率为零的瞬态位置,计算出最小的困油压力,并与现有文献的试验结果做比对分析.结果表明,最小困油压力发生在卸荷槽开口附近,处于内侧时一般会出现负值的最小困油压力,处于外侧时可近似为进口压力;最小困油压力由出口压力和转速2部分的线性贡献所得,出口压力的影响为正,转速的影响为负;泵卸荷槽整体向进油侧偏置比较合理.所建解析式可快速求出最小困油压力及其发生位置,从而节省大量的过程计算,减少过程仿真的累积误差,结果更精确.
To overcome the limitations of testing and simulation,an analytic formula on minimal trapped-oil pressure in an external gear pump was tentatively established.For the expansion phase of trapped-oil,both cases of small backlash value and large backlash value,the long hole flow formula was applied to calculate the differential pressure flow through backlash.The leak path was simplified to calculate the axial leak flow from trapped-oil zone.The minimal trapped-oil pressure was calculated in the transient position that the expansion ratio of trapped-oil volume was equal to trapped-oil leak flow,that is to say,the change ratio of trapped-oil pressure with time was zero.The calculated results were then compared with the experimental results of the existing literature.The results show that,the position of minimal trapped-oil pressure was around the opening of relief groove,when in the inside,the negative minimal trapped-oil pressure would occur;while in the outside,the minimal trapped-oil pressure would approach closely the inlet-pressure;the minimal trapped-oil pressure was contributed by the outlet-pressure and rotation speed,among which,the minimum trapped-oil pressure was in a negative linear relationship with speed and a positive linear relationship with outlet-pressure;the overall offset of two relief grooves to inlet side was reasonable,etc.It can be finally concluded that,with the established analytic formula,the minimal trapped-oil pressure and its position can be promptly found without going through a large number of processes.Thus,the accumulated errors from process simulation are reduced and the minimal trapped-oil pressure is more accurate.
出处
《排灌机械工程学报》
EI
北大核心
2013年第12期1049-1055,共7页
Journal of Drainage and Irrigation Machinery Engineering
基金
安徽省自然科学研究项目(2004KJ317)
成都大学人才引进基金资助项目(20804)
关键词
外啮合齿轮泵
最小困油压力
轴向泄漏
齿侧间隙
卸荷槽间距
external gear pump
the minimal trapped-oil pressure
axial leakage
backlash
distance of two relief grooves
