泵用双斜型卸荷槽及困油性能分析

Trapped-oil Performance Analysis for Double Oblique-shaped Relief Groove of Pumps

为满足渐开线外啮合齿轮泵困油卸荷之需要,提出了一种具有更大卸荷面积、易加工的双斜型卸荷槽。基于常用的矩形卸荷槽,针对双齿啮合区与单齿啮合区之间不同的困油特点和卸荷措施,首先给出了双斜型卸荷槽的结构和形位设计;其次,由三维模型旋转面积的测量方法,得到一个困油周期内的卸荷面积,最后通过所建立的困油模型,进行双斜型、矩形卸荷槽下两类区域内的困油压力仿真。结果表明:双斜型较矩形能大幅提升卸荷面积,其中,双区的最大卸荷面积提升1.17倍,单区提升11.7倍;最大困油压力峰值,双区降低46.2%,对排油压力仅增加4.3%;单区则降低60.2%和仅增加1.6%,可视为无困油现象;双斜型两侧的型线轮廓,均由5个直线段和3个?2.0mm圆弧段组成,结构简单、易加工等。为卸荷槽创新提供一种新的途径。

For the need to release trapped-oil pressure in external gear pumps with in-volutes gear pairs.Firstly,compared with current rectangle-shaped relief groove,and based on the different trapped-oil characteristics and relief measure in double meshing teeth range from single meshing tooth range,a new double oblique-shaped profile with larger relief area and simple processing was proposed for trapped-oil relief,then it’s construction was described,its shape and location dimensions was designed in detail.Secondly,by the 3D model rotating method and area measurement method,all dynamic relief areas of each different meshing position were measured.Thirdly,form the trapped-oil process cycle and a created simple emulating model,different trapped-oil pressure simulation calculations in double meshing teeth range from single meshing tooth range,was respectively executed in different grooves with double oblique-shaped from rectangle-shaped.All results indicated that relief area was greatly enlarged by the new double oblique-shaped relief groove than current rectangle-shaped relief groove,among them,the maximum relief area in double meshing teeth range was enlarged by 1.17 times,by 11.7 times in single meshing tooth range;the maximum trapped-oil pressure in double meshing teeth range was decreased by 46.2%and only was 4.3%more than discharge pressure,and by 60.2%and only was 1.6%in single meshing tooth range,which could be considered as a no trapped-oil phenomenon;and each profiled outlines of double oblique-shaped relief grooves on both sides of suction oil and discharge oil was enclosed by 5 straight line segments and 3 circular arc segments with?2.0 mm,which could be considered as a simple structure and an easy processing,etc.It is concluded that a new design approach to relief groove is provided for gear pumps.