Seal element is an important component of roller-cone bit. In order to improve the sealing performance and service life of roller-cone bit under high temperature, a new seal structure with multi-segment arcs is designed and the structural parameters of this sealing ring are optimized by response surface method and finite element method. Firstly, the hydrogenated nitrile-butadiene rubber is used to improve the seal performance under high temperature, and the uniaxial, planar, and biaxial tensile experiments are carried out to study the constitutive model of this rubber. Then, a three-dimension transient thermo-mechanical coupling model is established. The comparison of sealing performance between the new structural seal and the traditional O-ring seal is implemented under high temperature through the proposed FEM and laboratory experiments. The results show that the new structural seal has lower contact pressure and Mises stress than the standard O-ring seal, and the service life of the former is almost twice of the later one. Additionally, a composite drill bit using the new structural seal is applied to a deep drilling. After servicing a certain time, it shows that the wearing capacity is very small. The results show that the new structure seal ring can adapt to high temperature environment and the optimization method is feasible.

密封元件是牙轮钻头的重要组成部分。为了提高高温条件下圆锥锥钻头的密封性能和使用寿命，设计了一种新型的多段弧形密封结构，并通过响应面法和有限元法对该密封圈的结构参数进行了优化。首先，使用氢化丁腈橡胶提高了高温下的密封性能，并进行了单轴，平面和双轴拉伸试验，以研究该橡胶的本构模型。然后，建立了三维瞬态热力耦合模型。通过提出的有限元分析和实验室实验，在高温下对新型结构密封件和传统O形圈密封件的密封性能进行了比较。结果表明，新型结构密封件的接触压力和Mises应力均低于标准O型圈密封件，前者的使用寿命几乎是后者的两倍。此外，使用新的结构密封件的复合钻头可用于深孔钻削。维修一定时间后，表明磨损量很小。结果表明，该新型结构密封圈能适应高温环境，优化方法是可行的。这表明磨损量很小。结果表明，该新型结构密封圈能适应高温环境，优化方法是可行的。这表明磨损量很小。结果表明，该新型结构密封圈能适应高温环境，优化方法是可行的。