牙轮钻头滑动轴承浮动套优化设计

Optimized Design of the Floating Bushing for the Sliding Bearing of Roller Bit

为了延长牙轮钻头滑动轴承的使用寿命,对带浮动套的牙轮钻头滑动轴承结构进行理论分析,并采用ANSYS软件对其进行有限元仿真。以浮动套的内、外间隙比和浮动套厚度为设计变量,以接触有限元分析的峰值接触压力为目标函数,用接触有限元方法建立了带浮动套的滑动轴承优化设计模型。优化结果表明,选择合适的浮动套内、外间隙比,不管其是否正常工作,都能大大改善牙轮钻头滑动轴承的接触压力和最大Mises应力,推荐内、外间隙比为2.2～2.8;浮动套能改善滑动轴承局部磨损,且浮动套厚度对其接触压力及峰值应力影响较小;选择合理的浮动套与不带浮动套的牙轮钻头滑动轴承相比,其接触压力降低了25.0%,最大Mises应力降低了32.2%。

To lengthen the service life of the sliding bearing of roller bit, a theoretical analysis of the sliding bearing structure of roller bit with floating ＇bushing was conducted. The ANSYS software was adopted to carry out a finite element simulation of it. The internal and external clearance ratio and thickness of floating bushing were taken as the design variables. The peak contact pressure of contact finite element analysis was taken as the objective function. The contact finite element method was used to establish the optimized design model of sliding bearing with floating bushing. The optimization shows that selection of suitable internal and external clearance ratio of the bushing, whether it works properly or not, can remarkably improve the contact pressure and the maximum Mises stress of the sliding bearing of roller bit. It is recommended that the internal and external clearance ratio be 2.2 to 2. 8. The bushing can improve the local wear of the bearing. The bushing thickness has relatively small effect on its contact pressure and peak stress. Compared with the sliding bearing of roller bit without the bushing, the bearing with reasonable bushing reduces its own contact pressure by 25.0% and its maximum Mises stress by 32.2%.