Patent ID: 6769500
Filing Date: 2004-08-03
Classification: E21B

Abstract:
A rock bit sealing structure assembly comprising:a spindle exterior surface and a cone interior surface defining seal compression surfaces therebetween; a seal positioned between said seal compression surfaces, and deformed under stress from said surfaces, and resting statically with respect to a first one of said surfaces while moving dynamically with respect to a second one of said surfaces; and an extension of said second surface which confines said seal from motion along said second surface; said extension having a profile which is complementary to the profile of said seal as deformed, and which provides a nonzero distributed preload stress to all portions of said seal in contact therewith, when standard lubricant-filling hydrostatic pressure is applied thereto; whereby said seal is constrained by said extension against moving in response to hydraulic pressure differentials, but is not dragged along by friction with said extension during normal operation.