我厂精矿工段共有九台S_2—4型水环式真空泵。在泵的运转中,经常发生真空泵的轴断裂事故。据统计,真空泵轴的使用寿命最长4到5个月,最短的只有一个多月。仅去年就更换了21根轴,造成检修频繁,备件消耗量大,对生产非常不利。从轴折断部位分析,大部分是在螺纹退刀槽处断裂(图1A—A断面)。此处轴径较小,受力大,而且此处有应力集中,为此我们将轴 I plant a total of nine mine concentrate section S_2-4 type water ring vacuum pump. In the pump operation, the vacuum pump shaft rupture often occur. According to statistics, the longest shaft life of vacuum pump 4 to 5 months, the shortest only more than a month. In the past year alone, 21 axles were replaced, causing frequent maintenance and spare parts consumption. This was very detrimental to production. Analysis of the break from the shaft, mostly at the thread undercut groove rupture (Figure 1A-A section). Here the shaft diameter is smaller, the force is great, and here there is stress concentration, for which we will shaft