我矿自1996年二期扩建投产以来,碎破车间3台圆锥破碎机频繁发生主轴折断事故,严重影响了矿山的正常生产。断轴的部位多发生在破碎圆锥底部球面的下方I－I断面处(参见图1)。从折断断面I－I的状态可以判断是属于疲劳破坏。一般来说它先是在危险断面处产生裂纹,然后随着 Since the second phase mine was put into operation in 1996, three mine shaft crushers frequently broke off in the crushing workshop, seriously affecting the normal production of mines. Broken axis of the site occurred in the bottom of the crushing cone spherical I-I section below (see Figure 1). From the broken section I-I state can be judged to belong to the fatigue damage. In general, it first cracks at the dangerous section and then follows