凹端圆柱滚子轴承在牙轮钻头上的应用分析

国内现有牙轮钻头滚动轴承多采用短圆柱滚子轴承结构,滚子边缘处存在应力集中现象,使得轴承接触表面极易发生疲劳破坏,为提高牙轮钻头滚动轴承抗接触疲劳寿命,提出在牙轮钻头滚动轴承中采用凹端圆柱滚子的方案。利用有限元方法,分析普通圆柱滚子和凹端圆柱滚子在径向载荷作用下,滚子外圆柱面上的接触应力分布情况,并对凹端圆柱滚子结构参数(凹端深度及凹口直径)进行优化分析。与普通圆柱滚子相比,凹端圆柱滚子最大接触应力降低22.33%,其优化结构参数为凹端深度4.4 mm,凹口直径5 mm。结果表明,凹端圆柱滚子能有效克服普通圆柱滚子的两端应力集中现象,接触应力沿轴向分布均匀,最大接触应力明显减小,提高了滚动轴承的抗接触疲劳能力并延长其疲劳寿命。

Application of deep end-cavity cylindrical roller bearings to cone bits

In China, the roller bearing cone bit is now equipped with short cylindrical roller, which has stress centralization on the edge, and it easily causes fatigue failure on the contact area. In order to prolong the service life of roller bearing, a deep end-cavity roller is applied to roller bearing of cone bits. Using Finite Element Analysis (FEA) methods, the contact stresses of common column roller and deep end-cavity roller are analyzed under the radical stress, and the structure parameters of latter are optimized. The deep end-cavity roller reduces its maximum contact stress by 22.33 percent than the common column roller, and the depth of its deep end and the diameter of its notch are optimized to 4.4 mm and 5 mm respectively. Results show that the deep end-cavity roller can overcome stress centralization which appears easily to common column roller, and reduce the maximum contact stress apparently and increase the anti-fatigue failure, at the same time prolong the service time of the bearing.