Mechanical behavior and sealing performance of HAR sealing system in roller cone bits.

Two numerical models of HAR ring and O-ring sealing systems for roller cone bits were established in this paper. The stress-strain distribution was analyzed by finite element method. Effects of compression ratio, fluid pressure, ambient temperature and friction coefficient on mechanical behavior and sealing performance were studied. The results show that the HAR ring has better sealing performance than O-ring in the same working condition. The HAR ring can realize multi-stage sealing to increase the reliability of sealing. The high stress region appears at the sharp corner below the shaft. The sealing performance and the von Mises stress is enhanced with compression ratio and fluid pressure increasing. Under a high working temperature field, the sealing surface of HAR ring fails easily. The contact pressure fluctuation of the sealing surface easily appears by friction coefficient. Sharp-angled regions of the HAR ring near S.S.3, S.S.5 and S.S.6 fail easily. [ABSTRACT FROM AUTHOR]