upper device——includes parts of upper casing, top cover, discharge outlet (with anti back feed plate), head shaft and backstop.
上部装置——有上部机壳、上罩、卸料口(装有防回料板)、头轴装配、逆止器等部件。
in order to improve the efficiency of the quality test and control of the head shaft of oil pump, we designed a general measurement apparatus for measuring the diameter of the head shaft.