Research on sealing mechanism and structural improvement of metal sealing structures for high speed drill bits

The main causes of metal seal failure are studied and the main judgment criteria for metal seal failure are provided based on the structural characteristics in this paper. Mechanical analysis is conducted on the assembly and compression process of single metal seals, and the theoretical relationship between the contact pressures of the dynamic sealing surface of single metal seals is obtained. The finite element software was adopted to simulate the assembly process of a single metal seal. The results show that the sealing washer limited the downward deformation of the energy supply ring. The stress is concentrated at the chamfer at the lower end of the original sealing washer and metal ring, which is leading to the failure of the sealing washer. The new sealing structure can not only enhance the function of the energy supply ring on the metal sealing force, but also reduce the normal force of the sealing washer. It is concluded that the new sealing structure can improve the bearing sealing performance of small-sized cone drills through on-site drilling experiments. The conclusion has a certain guiding effect on the design and application of high speed bit.