压力角对齿轮泵整体性能的耦合影响与分析

Comprehensive Influence and Following Analysis of Pressure-angle on Overall Performance of Gear Pumps

为挖掘压力角对齿轮泵整体性能的综合影响及分析,以20°标准压力角及25°大压力角和大侧隙齿轮副为例,在分析压力角对齿轮副传动平稳性、泵内密封、输出流量特性、泵轻量化效果等性能的基础上,重点分析大压力角对重迭系数和卸荷面积及其困油压力的综合影响。结果表明:相对于20°的标准压力角,25°时虽然重迭系数下降9.64%,流量脉动系数下降7.33%,单位排量泵体积下降0.37%,最大困油流量下降49.14%,但齿顶压力角增大10.58%,顶齿厚角下降16.36%,卸荷面积大幅下降69.20%,由此虽然明显改善了流量脉动,但是降低了传动平稳性和径向密封效果,且对泵的轻量化效果和困油现象的改善很小;轴向缝隙对困油现象的缓解效果更灵敏更明显;针对齿轮泵整体性能的改善而言,大压力角并非有效方案。

In order to explore and analyse the comprehensive effect of pressure-angle on the overall performance of gear pumps,by a large pressure-angle of 25°relative to the standard pressure-angle of 20°and gear pair with large backlash as example,the influence of pressure-angle on the performance of gear transmission stability,radial seal inside gear pump,output flow characteristics,pump lightweight effect firstly;the comprehensive effect of high pressure-angle on overlap coefficient,relief area and following trapped-oil pressure is analyzed finally.All results show that compared with the standard pressure-angle of 20°,contact ratio,flow ripple factor,pump volume per unit displacement,the maximum trapped-oil flow respectively decreased by 9.64%,7.33%,0.37%,49.14%at 25°,but addendum pressure angle increased by 10.58%,addendum thickness angle decreased by 16.36%,and relief area decreased by 69.20%significantly;therefore,flow-ripple is obviously improved,but the transmission stability and radial sealing effect are reduced,and the lightweight effect and trapped oil phenomenon are little improved;the axial gap has a more sensitive and obvious effect on the relieving trapped-oil phenomenon,etc.It is concluded that the large pressure-angle is not an effective scheme to improve overall performance of gear pump.