牙轮钻头采用空心圆柱滚子轴承的理论探讨

Adopting hollow cylindrical roller bearing in cone bit.

为了提高牙轮钻头滚动轴承的抗接触疲劳能力 ,提出在牙轮钻头滚动轴承中采用空心圆柱滚子的方案 ,在对其接触情况进行了深入研究。首先应用弹性曲梁理论分析了单个空心圆柱滚子在径向对顶集中压力作用下的压缩变形以及滚子内外圆柱面上的拉压应力分布情况 ,并采用当量弹性模量法计算其与半空间平面接触时的接触应力分布。为了分析空心圆柱滚子轴承的载荷分布 ,在分析滚子与内外滚道接触变形量构成的基础上 ,提出了空心圆柱滚子载荷分布的迭代算法。结果表明 ,无论是单个滚动体的最大接触应力 ,还是整个轴承的载荷分布情况 ,只要有效控制空心滚子的空心度 。

In order to improve the contact fatiue resistance of the roller bearing in a cone bit, it is proposed to adopt hollow cylindrical rollers. By adopting the elastic curved-beam theory ,the radial compressive deformation of single roller is analyzed, and the distribution of compressive/tensile stress on the inner/outer cylindrical surface is also investigated. By using the equivalent-elastic-modulus method, the contact stress distrbution between the howwlow roller and half space is calculated. To study the load distribution of hollow roller bearing,the iterative algorithm is adopted based on understanding the construction of the total elastic deformation of roller and raceways. It is illustrated that, if the hollowness is controlled properly, the hollow cylindrical roller will be more preferable than the corresponding solid cylindrical roller whether consdering the single roller's maximum contact pressure or the bearng system's load distribution.