Double W-type combined metal seal structure for roller drill bits

Abstract

The double W-shaped combined metal sealing structure is used for the roller bit. The dynamic sealing ring is located at the top of the sealing cavity, interference fits in the inner hole of the roller, and rotates with the roller. The sealing cavity is surrounded by the inner hole of the roller and the root of the roller shaft neck. The dynamic sealing ring and the static sealing ring rotate relatively, and the end faces cooperate with each other to form a dynamic sealing surface. An outer rectangular groove is provided on the outer cylindrical surface of the upper part of the static sealing ring. An outer W-shaped rubber ring is embedded in the outer rectangular groove. The opening of the outer W-shaped rubber ring faces the outer cylindrical surface of the sealing cavity. The outer W-shaped rubber ring fits tightly with the static sealing ring and the outer cylindrical surface of the sealing cavity to form a static sealing surface. The bottom of the static sealing ring is embedded in the groove of the inner W-shaped rubber ring. The inner W-shaped rubber ring is compressed and embedded between the static sealing ring and the root of the roller shaft neck, and keeps tight fit with the static sealing ring, the lower end surface of the sealing cavity and the inner cylindrical surface to form a static sealing surface. The opening of the inner W-shaped rubber structure faces the inner cylindrical surface of the sealing cavity. An oil storage tank is provided on the groove of the inner W-shaped rubber ring.

Description

Technical Field

[0001] The invention relates to a double W-type combined metal sealing structure for a roller drill bit. Background Art

[0002] Metal seal is a common rotating dynamic seal in downhole roller drill bits. Compared with traditional O-ring rubber seals, it has the advantages of high temperature resistance, wear resistance, and wide applicable speed. It is widely used in oil and gas and mineral mining and other related industries. Taking a single metal seal as an example, the sealing structure consists of a dynamic seal ring, a static seal ring, an O-shaped rubber ring and a rubber support ring. When the roller drill bit is working, the O-shaped rubber ring and the rubber support ring are compressed and deformed by the grease inside the sealing system and the mud outside the sealing system, and they are close to the static ring to form a static seal; at the same time, there is relative rotation between the dynamic ring and the static ring, and an oil film is formed at the sealing end face to form a dynamic seal. However, in the high-temperature and high-pressure multiphase flow environment underground, the metal seal end face is prone to thermal deformation. In addition, the high-frequency vibration of the roller drill bit makes the metal seal in a long-term unstable working state. At the same time, the abrasive particles in the surrounding mud continue to invade, and the abrasive wear of the metal seal end face is aggravated, which soon causes 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, easy sealing failure and weak vibration resistance of existing metal sealing structures under high temperature, high pressure and abrasive working conditions, it is necessary to further design a new metal sealing structure to effectively block external particles from entering the sealing end face, maintain stable and reliable operation of the metal seal, and improve the service life of the sealing system. Summary of the invention

[0004] The present invention aims to overcome the above problems of the prior art and proposes a double W-shaped combined metal seal structure for a roller drill bit which has a simple structure, strong wear resistance and good anti-vibration effect.

[0005] The double W-shaped combined metal seal structure for a roller drill bit of the present invention is characterized by:

[0006] It includes a dynamic seal ring, a static seal ring, an outer W-shaped rubber ring and an inner W-shaped special-shaped rubber ring. The dynamic seal ring is located at the top of the seal cavity, is press-fitted into the inner hole of the cone, and rotates with the cone. The seal cavity is formed by the inner hole of the cone and the root of the cone journal of the cone palm, and includes an upper end face, a lower end face, an outer cylindrical surface and an inner cylindrical surface. The dynamic seal ring and the static seal ring rotate relative to each other, and their end faces cooperate with each other to form a dynamic seal surface. An outer rectangular groove is provided on the outer cylindrical surface of the upper part of the static seal ring, and the outer W-shaped rubber ring is embedded in the outer rectangular groove. The opening of the outer W-shaped rubber ring faces the outer cylindrical surface of the seal cavity, and the outer W-shaped rubber ring is closely attached to the static seal ring and the outer cylindrical surface of the seal cavity to form a static seal surface. The bottom of the static seal ring is embedded in the groove of the inner W-shaped special-shaped rubber ring. The inner W-shaped special-shaped rubber ring includes an inner W-shaped rubber structure in the upper part and a U-shaped rubber structure in the lower part, and is compression-embedded between the static seal ring and the root of the cone journal of the cone palm, and is closely attached to the static seal ring, the lower end face and the inner cylindrical surface of the seal cavity to form a static seal surface. The opening of the inner W-shaped rubber structure faces the inner cylindrical surface of the seal cavity. An oil storage groove is provided on the groove of the inner W-shaped special-shaped rubber ring.

[0007] Preferably, a plurality of the oil storage grooves are spaced apart on the groove.

[0008] Another technical solution of the double W-shaped combined metal seal structure for a cone bit according to the present invention is characterized in that:

[0009] It includes a dynamic seal ring, a static seal ring, an outer W-shaped rubber ring, an inner W-shaped rubber ring and a rubber support ring. The dynamic seal ring is located at the top of the seal cavity, is press-fitted into the inner hole of the cone, and rotates with the cone. The seal cavity is formed by the inner hole of the cone and the root of the cone journal of the cone palm, and includes an upper end face, a lower end face, an outer cylindrical surface and an inner cylindrical surface. The dynamic seal ring and the static seal ring rotate relative to each other, and their end faces cooperate with each other to form a dynamic seal surface. An outer rectangular groove and an inner rectangular groove are respectively provided on the outer cylindrical surface and the inner cylindrical surface of the upper part of the static seal ring, and a lower rectangular groove is provided on the bottom end face. The outer W-shaped rubber ring is embedded in the outer rectangular groove. The opening of the outer W-shaped rubber ring faces the outer cylindrical surface of the seal cavity, and the outer W-shaped rubber ring is closely attached to the static seal ring and the outer cylindrical surface of the seal cavity to form a static seal surface. The inner W-shaped rubber ring is embedded in the inner rectangular groove. The opening of the inner W-shaped rubber ring faces the inner cylindrical surface of the seal cavity, and the inner W-shaped rubber ring is closely attached to the static seal ring and the inner cylindrical surface of the seal cavity to form a static seal surface. The upper part of the rubber support ring is provided with an inner groove and an outer groove. The bottom of the rubber support ring is embedded in the groove of the root of the cone journal of the cone palm to form a static seal surface. The bottom of the static seal ring is embedded in the inner groove and the outer groove of the rubber support ring and is closely attached to form a static seal surface. An oil storage groove is provided on the inner groove and the outer groove of the rubber support ring.

[0010] Preferably, 1 to 3 oil storage grooves are spaced apart on the inner groove and the outer groove.

[0011] The beneficial effects of the present invention are:

[0012] The double W-type combined metal seal structure for roller drill bits adopts a static seal ring side wall slot supplemented by a double W-type rubber ring group to achieve multiple seals in a narrow sealing space. It has a simple structure, easy installation, and is stable and reliable.

[0013] The double W-shaped rubber ring group can be arranged on both sides of the static sealing ring in an up-down staggered or symmetrical manner, or can be integrated with the bottom rubber support ring to form an integrated inner W-shaped rubber ring. Within the expected service life of the sealing system, only the W-shaped rubber ring can be replaced to ensure good overall sealing performance.

[0014] The outer W-shaped rubber ring in the double W-shaped rubber ring group can act as the first barrier before the mud enters the dynamic seal surface, using the multi-stage seal and multiple closed cavities formed by itself to block and retain abrasive particles in advance, greatly reducing the possibility of particles entering the dynamic seal surface; the inner W-shaped rubber ring (or inner W-shaped rubber ring) can effectively prevent the leakage of grease, and on the other hand, it works together with the outer W-shaped rubber ring to offset the frequently changing three-way force on the static seal ring through its own compression and expansion deformation and the dynamic balance of the side wall double ring group, and weaken the axial and radial vibration of the sealing system caused by the operation of the roller bit. Even under high pressure, it can ensure that the static seal ring is relatively stable and the offset is small, enhancing the reliability and overall performance of the sealing system.

[0015] The bottom of the static seal ring is embedded in the inner W-shaped rubber ring or rubber support ring, which can not only keep the position of the static seal ring relatively fixed, further enhance the anti-vibration performance, but also effectively prevent the mud from entering the sealing system through the bottom, ensuring the reliability of the bottom static seal. In addition, an oil storage tank is opened on the contact surface between the bottom of the static seal ring and the rubber support ring, which can reduce friction and also retain and buffer a small amount of intruding particles, greatly reducing the generation of abrasive wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic cross-sectional view of the roller drill shaft used in the present invention.

[0017] Figure 2 It is a partially enlarged view of Example 1 of the present invention.

[0018] Figure 3 It is a partial enlarged view of Example 2 of the present invention.

[0019] Figure 4 It is a partial enlarged view of the outer W-shaped rubber ring of the present invention. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings.

[0021] Refer to the attached figure:

[0022] Example 1: The double-W-shaped combined metal seal structure for a roller cone bit according to the present invention includes a dynamic seal ring 1, a static seal ring 2, an outer W-shaped rubber ring 3, and an inner W-shaped special-shaped rubber ring 4. The dynamic seal ring 1 is located at the top of the seal cavity 5 and is in interference fit with the inner hole of the roller cone 6 and rotates with the roller cone 6. The seal cavity 5 is formed by the inner hole of the roller cone 6 and the root of the journal 7 of the cutter, and includes an upper end face 51, a lower end face 52, an outer cylindrical surface 53, and an inner cylindrical surface 54. The dynamic seal ring 1 and the static seal ring 2 rotate relative to each other, and their end faces cooperate with each other to form a dynamic seal surface. An outer rectangular groove 21 is provided on the outer cylindrical surface of the upper part of the static seal ring 2, and the outer W-shaped rubber ring 3 is embedded in the outer rectangular groove 21. The opening of the outer W-shaped rubber ring 3 faces the outer cylindrical surface 53 of the seal cavity 5, and the outer W-shaped rubber ring 3 is in close contact with the static seal ring 2 and the outer cylindrical surface 53 of the seal cavity 5 to form a static seal surface. The bottom of the static seal ring 2 is embedded in the groove 41 of the inner W-shaped special-shaped rubber ring 4. The inner W-shaped special-shaped rubber ring 4 includes an inner W-shaped rubber structure 42 in the upper part and a U-shaped rubber structure 43 in the lower part, and is compression-fitted between the static seal ring 2 and the root of the journal 7 of the cutter, and is in close contact with the static seal ring 2, the lower end face 52 and the inner cylindrical surface 54 of the seal cavity 5 to form a static seal surface. The opening of the inner W-shaped rubber structure 42 faces the inner cylindrical surface 54 of the seal cavity 5. An oil storage groove 44 is provided on the groove 41 of the inner W-shaped special-shaped rubber ring 4. One to three oil storage grooves 44 can be provided at intervals on the groove 41.

[0023] Embodiment 2 is based on the double W-shaped combined metal sealing structure for the roller bit of the present invention, and the arrangement and matching of the W-shaped rubber ring and the rubber support ring are changed, including a dynamic sealing ring 1, a static sealing ring 2, an outer W-shaped rubber ring 3, an inner W-shaped rubber ring 8 and a rubber support ring 9. The dynamic sealing ring 1 is located at the top of the sealing cavity 5, interference fits in the inner hole of the roller 6, and rotates with the roller 6. The sealing cavity 5 is surrounded by the inner hole of the roller 6 and the root of the roller journal 7, including an upper end face 51, a lower end face 52, an outer cylindrical surface 53 and an inner cylindrical surface 54. The dynamic sealing ring 1 and the static sealing ring 2 rotate relative to each other, and the end faces cooperate with each other to form a dynamic sealing surface. An outer rectangular groove 21 and an inner rectangular groove 22 are respectively provided on the outer cylindrical surface and the inner cylindrical surface of the upper part of the static sealing ring 2, and a lower rectangular groove 23 is provided on the bottom end face. The outer rectangular groove 21 is embedded with an outer W-shaped rubber ring 3, the opening of the outer W-shaped rubber ring 3 faces the outer cylindrical surface 53 of the sealing cavity 5, and the outer W-shaped rubber ring 3 is tightly fitted with the static sealing ring 2 and the outer cylindrical surface 53 of the sealing cavity 5 to form a static sealing surface. The inner rectangular groove 22 is embedded with an inner W-shaped rubber ring 8, the opening of the inner W-shaped rubber ring 8 faces the inner cylindrical surface 54 of the sealing cavity 5, and the inner W-shaped rubber ring 8 is tightly fitted with the static sealing ring 2 and the inner cylindrical surface 54 of the sealing cavity 5 to form a static sealing surface. The upper part of the rubber support ring 9 is provided with an inner groove 91 and an outer groove 92, and the bottom of the rubber support ring 9 is embedded in the groove at the root of the tooth palm journal 7 to form a static sealing surface. The bottom of the static sealing ring 2 is embedded in the inner groove 91 and the outer groove 92 of the rubber support ring 9 to form a static sealing surface. The inner groove 91 and the outer groove 92 of the rubber support ring 9 are provided with oil storage grooves 93. The oil storage grooves 93 can be arranged 1 to 3 at intervals on the inner groove 91 and the outer groove 92.

[0024] The working principle of the present invention is as follows:

[0025] When the roller bit is working, the dynamic seal ring 1 is located at the top of the sealing cavity 5, interference fits the inner hole of the roller 6, rotates relative to the static seal ring 2, and the end faces cooperate with each other to form a dynamic seal surface. There are 1 to 2 rectangular grooves on the side wall of the static seal ring 2. The outer W-shaped rubber ring 3 fits tightly with the outer cylindrical surface 53 of the static seal ring 2 and the sealing cavity 5, forming a static seal surface on the outside of the static seal ring 2; the inner W-shaped rubber ring 4 (or the inner W-shaped rubber ring 8 and the rubber support ring 9) fits tightly with the lower end surface 52 and the inner cylindrical surface 54 of the static seal ring 2, the sealing cavity 5, and forms a static seal surface on the inside and lower part of the static seal ring 2.

[0026] High-pressure grease enters the sealing chamber 5 from the flow channel I, and mainly flows into the dynamic sealing surface along the gap between the inner wall surface of the dynamic sealing ring 1 and the tooth palm journal 7. In addition, a small amount of grease entering the gap between the inner cylindrical surface of the static sealing ring 1 and the tooth palm journal 7 is sealed by the inner W-shaped rubber ring 4 (or the inner W-shaped rubber ring 8), and the grease leaking from the dynamic sealing surface into the gap between the outer cylindrical surface of the static sealing ring 1 and the gear 6 is sealed by the outer W-shaped rubber ring 3.

[0027] The mud enters the sealing chamber 5 from the flow channel II. A part of the mud flows along the outer cylindrical surface 53 of the sealing chamber 5 toward the dynamic sealing surface, and is sealed by the outer W-shaped rubber ring 3. The other part of the mud flows along the lower end surface 54 of the sealing chamber 5 toward the other side of the static sealing ring, and is sealed by the inner W-shaped rubber ring 4 (or rubber support ring 9).

[0028] Taking the flow process of the mud liquid in the outer W-shaped rubber ring 3 as an example, the working principle of the W-shaped rubber ring is specifically described: the outer W-shaped rubber ring 3 is closely attached to the static sealing ring 2 and the outer cylindrical surface 53 of the sealing chamber 5 to form five closed spaces. The mud liquid is further divided when flowing through the outer W-shaped rubber ring 3, and flows to the gap between the outer W-shaped rubber ring 3 and the outer cylindrical surface 53 of the sealing chamber 5 (i.e., flow channel III) and the gap between the outer W-shaped rubber ring 3 and the outer rectangular groove 21 (i.e., flow channel IV). In flow channels III and IV, the mud liquid undergoes 3rd and 4th level sealing in turn. Due to the effect of multi-level sealing, most of the abrasive particles in the mud liquid are retained in the above five closed spaces, which greatly reduces the wear and disturbance caused by the intrusion of the mud liquid on the metal sealing end face.

[0029] In addition, an oil storage groove is provided on the contact surface between the bottom of the static sealing ring 2 and the inner W-shaped rubber ring 4 (or the rubber support ring 9), which can store a small amount of leaked grease to reduce end surface friction and play a good buffering role against the invasion of external mud liquid.

[0030] The contents described in the embodiments of this specification are merely an enumeration of implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms described in the embodiments. The protection scope of the present invention also includes equivalent technical means that can be thought of by those skilled in the art based on the inventive concept.

Claims

1. Double W-shaped combined metal seal structure for roller cone bit, characterized in that: It includes a dynamic seal ring, a static seal ring, an outer W-shaped rubber ring and an inner W-shaped special-shaped rubber ring; the dynamic seal ring is located at the top of the seal cavity, is interference-fitted in the inner hole of the roller cone, and rotates with the roller cone; the seal cavity is formed by the inner hole of the roller cone and the root of the journal of the cutter arm, and includes an upper end face, a lower end face, an outer cylindrical surface and an inner cylindrical surface; the dynamic seal ring and the static seal ring rotate relatively, and the end faces cooperate with each other to form a dynamic seal surface; an outer rectangular groove is provided on the outer cylindrical surface of the upper part of the static seal ring, and the outer W-shaped rubber ring is embedded in the outer rectangular groove, and the opening of the outer W-shaped rubber ring faces the outer cylindrical surface of the seal cavity, and the outer W-shaped rubber ring is in close contact with the static seal ring and the outer cylindrical surface of the seal cavity to form a static seal surface; the bottom of the static seal ring is embedded in the groove of the inner W-shaped special-shaped rubber ring; the inner W-shaped special-shaped rubber ring includes an inner W-shaped rubber structure in the upper part and a U-shaped rubber structure in the lower part, and is compression-fitted between the static seal ring and the root of the journal of the cutter arm, and is in close contact with the static seal ring, the lower end face and the inner cylindrical surface of the seal cavity to form a static seal surface; the opening of the inner W-shaped rubber structure faces the inner cylindrical surface of the seal cavity; an oil storage groove is provided on the groove of the inner W-shaped special-shaped rubber ring.

2. The double W-shaped combined metal seal structure for a roller drill according to claim 1, characterized in that: A number of the oil storage grooves are spacedly arranged on the groove.

3. Double W-shaped combined metal seal structure for roller cone bit, characterized in that: It includes a dynamic seal ring, a static seal ring, an outer W-shaped rubber ring, an inner W-shaped rubber ring and a rubber support ring; the dynamic seal ring is located at the top of the seal cavity, is interference-fitted in the inner hole of the roller cone, and rotates with the roller cone; the seal cavity is formed by the inner hole of the roller cone and the root of the journal of the cutter arm, and includes an upper end face, a lower end face, an outer cylindrical surface and an inner cylindrical surface; the dynamic seal ring and the static seal ring rotate relatively, and the end faces cooperate with each other to form a dynamic seal surface; an outer rectangular groove and an inner rectangular groove are respectively provided on the outer cylindrical surface and the inner cylindrical surface of the upper part of the static seal ring, and a lower rectangular groove is provided on the bottom end face; the outer W-shaped rubber ring is embedded in the outer rectangular groove, and the opening of the outer W-shaped rubber ring faces the outer cylindrical surface of the seal cavity, and the outer W-shaped rubber ring is in close contact with the static seal ring and the outer cylindrical surface of the seal cavity to form a static seal surface; the inner W-shaped rubber ring is embedded in the inner rectangular groove, and the opening of the inner W-shaped rubber ring faces the inner cylindrical surface of the seal cavity, and the inner W-shaped rubber ring is in close contact with the static seal ring and the inner cylindrical surface of the seal cavity to form a static seal surface; the upper part of the rubber support ring is provided with an inner groove and an outer groove, and the bottom of the rubber support ring is embedded in the groove of the root of the journal of the cutter arm to form a static seal surface; the bottom of the static seal ring is embedded in the inner groove and the outer groove of the rubber support ring and is in close contact to form a static seal surface; an oil storage groove is provided on the inner groove and the outer groove of the rubber support ring.

4. The double W-shaped combined metal seal structure for a roller drill according to claim 3, characterized in that: 1 to 3 oil storage grooves are spacedly arranged on the inner groove and the outer groove.

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