Dual-W-shaped combined type metal sealing structure for roller cone bit

Abstract

The invention discloses a dual-W-shaped combined type metal sealing structure for a roller cone bit. A movable sealing ring is positioned on the top of a sealing cavity, and is in interference fit toa roller cone inner hole, and rotates along with a roller cone; the sealing cavity is enclosed by the roller cone inner hole and a palm shaft neck root part; the movable sealing ring and a fixed sealing ring rotate relatively, and end surfaces of the movable sealing ring and the fixed sealing ring are mutually matched to form a movable sealing surface; an outer rectangular groove is formed in theouter cylindrical surface of the upper part of the fixed sealing ring; an outer W-shaped rubber ring is embedded into the outer rectangular groove; the opening of the outer W-shaped rubber ring facestowards the outer cylindrical surface of the sealing cavity; the outer W-shaped rubber ring tightly fits to the fixed sealing ring and the outer cylindrical surface of the sealing cavity to define a fixed sealing surface; the bottom of the fixed sealing ring is embedded into a groove of an inner W specially-shaped rubber ring; the inner W specially-shaped rubber ring is compressed and embedded between the fixed sealing ring and the palm shaft neck root part, and tightly fits to the fixed sealing ring, the lower end surface of the sealing cavity, and an inner cylindrical surface to define a fixed sealing surface; the opening of the inner W-shaped rubber structure faces towards the inner surface of the sealing cavity; and an oil storage slot is formed in the groove of the inner W specially-shaped rubber ring.

Description

technical field [0001] The invention relates to a double W-shaped combined metal sealing structure for a roller cone bit. Background technique [0002] Metal seal is a common rotary dynamic seal in downhole roller cone bits. Compared with traditional O-ring rubber seals, it has the advantages of high temperature resistance, wear resistance, and wide application speed. It is widely used in oil and gas and ore mining, etc. related professions. Taking the single metal seal as an example, the sealing structure is composed of a dynamic seal ring, a static seal ring, an O-shaped rubber ring and a rubber support ring. When the roller cone bit is working, the O-shaped rubber ring and the rubber support ring are compressed and deformed by the inner lubricating grease and the outer mud fluid of the sealing system at the same time, and they are close to the static ring to form a static seal; There is relative rotation, and an oil film is formed on the sealing end face to form a dynam...

AI Technical Summary

Problems solved by technology

However, in the downhole high-temperature, high-pressure multiphase flow environment, the end face of the metal seal is prone to thermal deformation, coupled with the high-frequency vibration of the roller cone bit, the metal seal is in a long-term unstable working state, and the abrasiveness of the surrounding mud fluid Particles continue to invade, and the abrasive wear on the end face of the metal seal is intensified, which will soon cause the seal to fail, thereby affecting the working efficiency and service life of the drill bit

[0003] Therefore, in order to overcome the problems of short working life, prone to seal failure and weak anti-vibration ability of the existing metal sealing structure under high temperature, high pressure and abrasive working conditions, it is necessary to further design a new metal sealing structure to effectively block the entry of external particles. Seal the end face, maintain the stable and reliable operation of the metal seal, and improve the operating life of the sealing system

Images