Research On The Mechanism Of High-speed Roller Cone Bit Spiral Seal Sealing And Sealing

Bearing seal is the weakest point in cone bit,the entry of cuttings is one of the most critical factors affecting the life of high-speed cone bits,designing a sealed structure with automatic sand removal is one of the most critical technologies to improve the life of drilling.This paper presents a new "helix combined seal" structure,using a new idea of sand removal and combined sealing,to solve this difficult problem,the purpose of this research was to provide a helical pump with a helical seal ring under high speed rotation,discharging the cuttings outside the sealed chamber,trying to improve the rubber ring sealing conditions so as to improve its sealing performance.In this paper,in view of this research,the following work has been done:(1)Developing theory research of helix combination sealing structure design:including the design of structural programs.comparison of structural programs;To determine the structure program,the design of structural parameters,including the design of the helix seal structural parameters,O-ring structure design parameters.(2)Developing simulation research on sand removal performance of new type of sealed structure,discrete phase model was used to simulate the movement of cuttings particles,through the analysis of fluid velocity field,pressure field,cuttings particle migration path,cutting particle retention time,analyzing the sand removal performance of the helix ring under the single speed.(3)Developing research on the influence of helix structure parameters on sand removal performance,by analyzing the velocity field,the pressure field and the time of the seal particles in the sealed cavity at different pitch,different sealing gaps,different helix angles,finding out the influence of structural parameters on the performance of sand removal,and a set of structural parameters with good sand removal performance are obtained.(4)A criterion for the evaluation of helix sand removal performance is proposed.(5)Finally,the comparative analysis of the new structure and the prototype structure of the sand removal performance,provide preliminary structural parameters for the follow-up study.This combination seal has a broad application prospects,and is suitable for all kinds of cone bit,composite drill bit,abrasive media mechanical seals such as mining machinery,drilling pumps,the successful development of the new structure broke the idea of the current passive seal,turn the passive seal to active seal,marking the birth of a new type of sealing concept,is expected to break the foreign monopoly on the field,will receive the sealing technology with independent intellectual property rights,resulting in huge economic value and social benefits.