Sealing connection structure and method for coal mine underground near-bit data receiver

Abstract

The invention discloses a sealing connection structure and method for an underground coal mine near-bit data receiver. The sealing connection structure comprises a head assembly, an electronic instrument shell and a tail assembly which are arranged in an outer pipe. The head assembly and the tail assembly are sealed at two ends of the electronic instrument shell, stepped holes and connecting threads are arranged at two ends of an inner hole of the electronic instrument shell, and a flat square is arranged on the outer wall. The head assembly comprises a head connector body, a rotating ring, a blocking piece and a semi-ring, the head connector body is provided with a stepped outer circle, a small section is provided with a positioning plane to be matched with an electronic instrument shell to achieve axial circumferential positioning, and a large section is provided with a sealing piece to be sealed with an outer pipe. And the rotating ring is sleeved on the middle section, is connected with the connecting thread, and is axially limited through the separation blade and the semi-ring to realize thread sealing and fixing. The connecting mode of the tail assembly is similar to that of the head assembly. The connecting method comprises the steps of mounting the rotating ring for axial limiting, threaded connection for positioning and looseness prevention, and support imbedding into the outer pipe communicating channel. The problems of connection loosening and sealing failure are solved, and the device is suitable for narrow underground environments.

Description

Technical Field

[0001] This invention belongs to the technical field of underground drilling measurement equipment in coal mines, specifically relating to a sealed connection structure and method for a near-drill bit data receiver in coal mines. Background Technology

[0002] In underground coal mine drilling, the connection structure of the near-bit data receiver directly affects the real-time transmission of measurement data and the reliability of the equipment. Traditional underground drilling systems rely on a screw motor to transmit real-time data collected by near-bit sensors, such as drill bit position and rock formation parameters. However, the rotational vibration and high torque characteristics of the screw motor make the connecting parts prone to loosening and misalignment, causing signal interruption or delay. Specifically, the receiver assembly is placed inside the outer tube of the near-bit data receiving section. The head assembly needs to establish a cable signal connection with the receiving antenna assembly and handle the high-pressure water passage. However, in existing designs, the connectivity between the cable passage and the water passage is poor, and improper sealing can easily lead to high-pressure water (pressure exceeding 10 MPa) seeping into the cable passage, corroding electronic components or short-circuiting circuits, causing signal transmission interruption. The threaded connection between the head connector and the electronic instrument housing is prone to loosening in the strong vibration environment downhole. The lack of axial limiting and circumferential anti-rotation mechanisms causes misalignment of the positioning plane, and the cable hole cannot accurately align with the wiring compartment of the outer tube. The cable insertion deviation reaches the millimeter level, affecting the stable transmission of weak electromagnetic wave signals (amplitude <1mV).

[0003] The connection issues of the tail assembly are also prominent. The tail needs to interface with the conventional MWD system via a transmission shaft, but the engagement connection between the two wing connectors and the outer tube relies on a single flange, which is prone to dislocation under vibration. The transition joint at the end of the transmission shaft is not well sealed. Although the material difference between the non-metallic outer joint and the metallic inner joint facilitates signal coupling, the sealing ring is prone to aging, causing radial leakage and interrupting signal connection. The threaded connection lacks anti-loosening design, and the rotating ring rotates circumferentially under torque, causing the stepped end face contact to fail, reducing the axial fixing force by more than 30%, and making it unable to withstand the axial tension and radial force during drilling.

[0004] These connection and sealing issues make it difficult to achieve a miniaturized, high-strength design for the downhole near-bit data receiver within the narrow space (diameter <150mm) behind the screw motor. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to solve the above problems and provide a sealed connection structure and method for a near-drill bit data receiver in coal mines. By using threaded sealing connection of the head assembly and tail assembly, positioning plane fit, axial limiting and anti-loosening limiting mechanism, the problem of loose connection and sealing leakage is solved, and stable signal transmission and environmental adaptability are achieved.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A sealed connection structure for a near-bit data receiver in a coal mine, the near-bit data receiver comprising a head assembly, an electronic instrument housing, and a tail assembly disposed within an outer tube of a near-bit data receiving subsection; the head assembly and the tail assembly are respectively sealed to both ends of the electronic instrument housing and supported within the outer tube by the head assembly and the tail assembly; The electronic instrument housing has stepped holes at both ends of its inner bore, and each stepped hole has a connecting thread; the outer wall of the electronic instrument housing has a flat square for a tool to turn the connecting thread. The head assembly includes a head connector body, a first rotating ring, a first baffle, and a first half-ring. The head connector body is disposed inside the outer tube, and its outer circumference is stepped, including a large section, a middle section, and a small section connected in sequence. The small section has a positioning plane, and the electronic instrument housing has a positioning plane that mates with the positioning plane, thereby achieving axial and circumferential positioning of the head connector body and the electronic instrument housing. The outer circumference of the large section has a sealing element, which is used to seal the connection with the outer tube. The first rotating ring is rotatably fitted onto the middle section. The first rotating ring has a thread for connecting with the electronic instrument housing. One end of the first rotating ring contacts the stepped end face of the head connector body, and the other end has the first baffle and the first half-ring. The first half-ring is fixed to the small section, and the first baffle axially limits the first rotating ring, thereby achieving threaded sealing connection and axial fixation between the head connector body and the electronic instrument housing. The tail assembly includes two wing connector bodies, a second half-ring, a second baffle, and a second rotating ring. The two wing connector bodies have an axially extending transmission shaft for signal transmission. The outer circumference of the two wing connector bodies is stepped, comprising a large section, a middle section, and a small section connected in sequence. The small section has a positioning plane that mates with a positioning plane on the electronic instrument housing to achieve axial and circumferential positioning of the two wing connector bodies relative to the electronic instrument housing. The large section has radially protruding two wing flanges that engage with grooves inside the outer tube to restrict the two wing connectors. The head body rotates circumferentially; the second rotating ring is rotatably fitted onto the middle section, and the second rotating ring is provided with a thread for connecting to the electronic instrument housing. One end of the second rotating ring contacts the stepped end face of the two-wing connector body, and the other end is provided with a second baffle and a second half-ring. The second half-ring is fixed to the small section, and the second rotating ring is axially limited by the second baffle, thereby realizing the threaded sealing connection and axial fixation between the two-wing connector body and the electronic instrument housing, as well as the engaging connection between the two-wing flanges and the outer tube.

[0007] Furthermore, the head connector body is provided with a cable passage hole and a water passage hole, and a water passage cavity is formed between the electronic instrument housing and the outer tube, with the water passage hole communicating with the water passage cavity; the head assembly is connected to the receiving antenna assembly of the near-drill bit data receiving section through the cable in the cable passage hole, and the tail assembly is connected to the conventional MWD through a transmission shaft, thereby realizing the signal connection between the head assembly and the receiving antenna assembly, the signal transmission between the tail assembly and the conventional MWD, and the water passage connection between the water passage hole and the water passage cavity.

[0008] Furthermore, one end of the wire-passing hole extends axially along the head connector body to the end face of the small segment and communicates with the inner cavity of the electronic instrument housing, while the other end extends radially along the head connector body to the outer circle of the large segment and communicates with the wiring compartment on the outer tube, thereby enabling the cable in the wire-passing hole to connect to the signal of the receiving antenna assembly through the wiring compartment and the inner cavity of the electronic instrument housing.

[0009] Furthermore, the water passage includes a first water passage and a second water passage; one end of the first water passage extends axially along the head connector body to the end face of the large section and communicates with the water passage inner hole of the receiving antenna assembly at the front end of the outer tube, and the other end extends radially along the head connector body to the outer circle of the middle section and communicates with the water passage cavity; the second water passage is located outside the first water passage, and the second water passage is waist-shaped, directly penetrating both end faces of the large section of the head connector body, thereby realizing radial and axial communication between the first water passage and the second water passage and the water passage cavity.

[0010] Furthermore, the first rotating ring includes a threaded section and a locking section. The threaded section is used for threaded connection with the electronic instrument housing. The locking section is provided with a screw. The middle section of the head connector body is provided with circumferentially distributed limiting grooves. The screw is screwed into the limiting grooves, thereby restricting the circumferential rotation of the first rotating ring, preventing the threads from loosening, and realizing an anti-loosening connection between the head connector body and the electronic instrument housing.

[0011] Furthermore, the locking section is provided with a flat square for a tool to turn the first rotating ring, thereby facilitating the threaded connection operation between the first rotating ring and the electronic instrument housing.

[0012] Furthermore, the first half-ring is provided with screws, and the small section of the head connector body is provided with screw holes. The first half-ring is fixed to the head connector body by the screws and screw holes. There are two first half-rings, which are fixed to the head connector body, thereby realizing the axial limiting and fixed connection of the first half-ring to the first rotating ring.

[0013] Furthermore, the head connector body has two sets of seals on the larger section, and the opening of the wire passage hole is located between the two sets of seals; the head connector body also has a seal, and is sealed to the electronic instrument housing through the seal, thereby achieving multiple sealing connections between the head connector body, the outer tube, and the electronic instrument housing, preventing high-pressure water from entering the wire passage hole.

[0014] Furthermore, multiple first water passage holes are distributed circumferentially within the head connector body; the opening of the first water passage hole on the middle section of the head connector body is located between the first rotating ring and the large section, thereby realizing multi-channel communication of the first water passage hole and avoidance positioning of the first rotating ring.

[0015] Furthermore, both the first rotating ring and the first half-ring are fixed to the head connector body by multiple circumferentially distributed screws, thereby achieving multi-point fixed connection of the first rotating ring and the first half-ring and improving the overall stability of the head assembly.

[0016] Furthermore, the second rotating ring includes a threaded section and a locking section. The threaded section is used for threaded connection with the electronic instrument housing, and the locking section is provided with a screw. The middle section of the two-wing connector body is provided with circumferentially distributed limiting grooves. The screw is screwed into the limiting grooves, thereby restricting the circumferential rotation of the second rotating ring, preventing the threads from loosening, and realizing the anti-loosening connection between the two-wing connector body and the electronic instrument housing.

[0017] Furthermore, the second half-ring is provided with screws, and the small section of the two-wing connector body is provided with screw holes. The second half-ring is fixed to the two-wing connector body by the screws engaging with the screw holes. There are two second half-rings, which are fixed to the two-wing connector body, thereby realizing the axial limiting and fixed connection of the second half-ring to the second rotating ring. The positioning plane and the two-wing flange are in the same direction as the two-wing connector body, thereby realizing the coordinated positioning and limiting function of the positioning plane and the two-wing flange.

[0018] Furthermore, a transition joint is provided within a large section of the two-wing connector body. The transition joint is connected to the end of the transmission shaft and is used to achieve signal docking between the transmission shaft and a conventional MWD system. The transition joint includes an outer joint and an inner joint. The outer joint is sealed to the two-wing connector body, and the inner joint is located inside the outer joint and connected to the transmission shaft. The outer joint is made of non-metallic material, while the inner joint and the transmission shaft are made of metallic material, thereby achieving a sealed signal docking connection between the transmission shaft and the conventional MWD system.

[0019] A method for connecting a downhole near-bit data receiver as described above includes the following steps: The first rotating ring is installed on the head connector body and is axially limited by the first baffle and the first half ring; the head assembly is sealed and connected to one end of the electronic instrument housing, and axial and circumferential positioning is achieved by the positioning plane, and the first rotating ring is connected to the connecting thread of the electronic instrument housing by the thread, while the circumferential rotation of the first rotating ring is limited by screws screwed into the limiting groove; at the same time, the head assembly is supported and placed in the outer tube to ensure that the wire hole is opposite to the wiring compartment of the outer tube and the water hole is connected to the water cavity; The first rotating ring is installed on the two-wing connector body and axially limited by the second half-ring and the second baffle. The tail assembly is sealed and connected to the other end of the electronic instrument housing. Axial and circumferential positioning and locking are achieved by the positioning plane and the two-wing flanges. The second rotating ring is connected to the connecting thread of the electronic instrument housing by the thread. At the same time, the circumferential rotation is limited by screws screwed into the limiting groove. The tail assembly support is placed inside the outer tube, and the transmission shaft is connected to the conventional MWD signal, thereby realizing the signal transmission and water connection of the downhole near-bit data receiver.

[0020] The beneficial effects of this invention are as follows: 1. This invention solves the problems of loose connections and signal delays in near-drill bit wireless data transmission across the screw motor by using a threaded sealing connection design for the head and tail components. Traditional systems suffer from seal failure leading to water intrusion into the cable passage. This invention utilizes multiple sets of seals to clamp the opening and precisely align the radial and axial cable passages with the junction box, ensuring stable transmission of cable signals to the inner cavity of the electronic instrument housing, avoiding interruptions, and improving real-time performance to the second level.

[0021] 2. Significantly improved connection positioning and anti-loosening mechanisms. The threaded sections of the first and second rotating rings match the stepped hole connection threads of the electronic instrument housing. The locking section screws are screwed into the circumferential limiting groove to restrict circumferential rotation, and the flat shape facilitates the tightening operation. The first and second half-rings are fixed with double-ring screws to fix the small screw holes, providing axial limiting. The circumferential distribution of multiple screws enhances the fixing force and ensures the accuracy of the wire hole relative to the wiring compartment and the MWD of the transmission shaft.

[0022] 3. To address the signal misalignment issue between the tail section and conventional MWD, the transmission shaft achieves signal coupling through an outer metal and inner non-metal sealing structure of the transition joint. The two wing flanges engage with the outer tube groove to restrict circumferential rotation, and the positioning planes work in the same direction to ensure continuous axial fixation, prevent vibration and loosening, and improve stability.

[0023] 4. This invention optimizes the connection design between the water passage hole and the water passage cavity. The first water passage hole is distributed in multiple circumferential directions to avoid the opening of the first rotating ring, and the second water passage hole is waist-shaped and penetrates a large section of the end face to realize a radial and axial water passage channel, reducing the pump pressure burden. It is suitable for the miniaturization requirements of the narrow space behind the screw motor, and the overall pressure resistance is improved, meeting the explosion-proof standards of coal mines.

[0024] 5. Modular assembly method improves economy and maintainability. The process involves first installing the axial limit of the rotating ring, then using threaded connections for positioning and anti-loosening, and finally inserting the support into the outer tube connecting channel. This facilitates quick assembly and disassembly downhole, requiring no special tools, only a standard wrench. The transition joint's sealed connection further isolates high-pressure water, strengthens signal transmission anti-interference, improves drilling trajectory accuracy, reduces hysteresis deviation, lowers costs and risks, and extends equipment life by 50%.

[0025] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the installation of the sealed connection structure of the near-drill bit data receiver in a coal mine according to the present invention.

[0027] Figure 2 This is a perspective view of the sealed connection structure of the near-drill bit data receiver in a coal mine according to the present invention.

[0028] Figure 3 This is a cross-sectional view of the sealed connection structure of the near-drill bit data receiver in a coal mine according to the present invention.

[0029] Figure 4 This is a cross-sectional view of the head assembly in this invention.

[0030] Figure 5 for Figure 4 The left view.

[0031] Figure 6 This is a perspective view of the head assembly in this invention.

[0032] Figure 7 This is a structural diagram of the head connector body in this invention.

[0033] Figure 8 This is a schematic diagram of the tail assembly in this invention.

[0034] Figure 9 This is a cross-sectional view of the tail assembly in this invention.

[0035] Figure 10 This is a schematic diagram of the electronic instrument casing structure in this invention.

[0036] Figure 11 for Figure 10 Side view.

[0037] Reference numerals: 1-Receiving antenna assembly; 2-Head assembly; 3-Outer tube; 4-Receiving board assembly; 5-Battery assembly; 6-Signal board assembly; 7-Electronic instrument housing; 8-Tail assembly; 201-Head connector body; 201a-Wire passage hole; 201b-Wire passage hole; 201c-First water passage hole; 201d-Second water passage hole; 201e-Positioning plane; 201f-Limiting groove; 201g-Semi-ring mounting groove; 202-Seal; 203-Rotating ring; 204-Fixing screw; 205-Block 206-Half-ring; 207-Screw; 208-Seal; 301-Connector compartment; 701-Tail positioning surface; 702-Head positioning surface; 703-Head connecting thread; 704-Tail connecting thread; 801-Two-wing connector body; 801a-Positioning plane; 801b-Two-wing flange; 801c-Limiting groove; 802-Half-ring; 803-Screw; 804-Baffle; 805-Fixing screw; 806-Rotating ring; 807-Transmission rod; 808-Outer connector; 809-Inner connector. Detailed Implementation

[0038] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0039] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0040] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0041] Example 1 like Figures 1-11The diagram shows a sealed connection structure for a near-drill bit data receiver in a coal mine. The near-drill bit data receiver includes a head assembly 2, an electronic instrument housing 7, and a tail assembly 8, all housed within an outer tube 3 of a near-drill bit data receiving sub. The head assembly 2 and tail assembly 8 are respectively sealed to both ends of the electronic instrument housing 7 and supported within the outer tube 3. The electronic instrument housing 7 has stepped holes at both ends of its inner bore, and each stepped hole contains connecting threads 703 and 704. The outer wall of the electronic instrument housing 7 has a flat square for screwing the connecting threads 703 and 704. The head assembly 2 includes a head connector body 201, a first rotating ring 203, a first baffle 205, and a first half-ring 206. The head connector body 201 is located inside the outer tube 3, and its outer circumference is stepped, including a large section, a middle section, and a small section connected in sequence. The small section has a positioning plane 201e, and the electronic instrument housing 7 has a positioning plane 702 that mates with the positioning plane 201e, achieving axial and circumferential positioning of the head connector body 201 and the electronic instrument housing 7. The outer circumference of the large section has a sealing element 208, which seals the connection with the outer tube 3. A first rotating ring 203 is rotatably fitted onto the middle section. The first rotating ring 203 has threads for connecting with the connecting threads 703 of the electronic instrument housing 7. One end of the first rotating ring 203 contacts the stepped end face of the head connector body 201, and the other end has a first baffle 205 and a first half-ring 206. The first rotating ring 203 is axially limited by the first baffle 205 in the semi-ring mounting groove 201g fixed on the small section, thereby realizing the threaded sealing connection and axial fixation between the head connector body 201 and the electronic instrument housing 7; the tail assembly 8 includes two wing connector bodies 801, a second semi-ring 802, a second baffle 804, and a second rotating ring 806. The two wing connector bodies 801 are provided with a transmission shaft 807 that passes through the axis along the axis. The transmission shaft 807 is used for signal transmission; the outer circle of the two wing connector bodies 801 is stepped, including a large section, a middle section, and a small section connected in sequence; the small section is provided with a positioning plane 801a, which cooperates with the positioning plane 701 on the electronic instrument housing 7 to realize the axial and circumferential connection between the two wing connector bodies 801 and the electronic instrument housing 7. The large section has radially protruding two-wing flanges 801b, which engage with the grooves inside the outer tube 3 to restrict the circumferential rotation of the two-wing connector body 801. The second rotating ring 806 is rotatably fitted onto the middle section. The second rotating ring 806 has threads that connect with the connecting threads 704 of the electronic instrument housing 7. One end of the second rotating ring 806 contacts the stepped end face of the two-wing connector body 801, and the other end has a second baffle 804 and a second half-ring 802. The second half-ring 802 is fixed to the small section and the second baffle 804 axially limits the second rotating ring 806, thereby achieving threaded sealing connection and axial fixation between the two-wing connector body 801 and the electronic instrument housing 7, as well as the engaging connection between the two-wing flanges 801b and the outer tube 3.

[0042] The head connector body 201 has cable passage holes 201a and 201b and water passage holes 201c and 201d. A water passage cavity is formed between the electronic instrument housing 7 and the outer tube 3, and the water passage holes 201c and 201d communicate with the water passage cavity. The head assembly 2 is connected to the receiving antenna assembly 1 of the near-drill bit data receiving section through the cable in the cable passage hole 201a. The tail assembly 8 is connected to the conventional MWD through the transmission shaft 807. One end of the cable passage hole 201a extends axially along the head connector body 201 to the end face of the short section and communicates with the inner cavity of the electronic instrument housing 7. The other end extends radially along the head connector body 201 to the outer circle of the long section and communicates with the wiring compartment 301 on the outer tube 3, thereby realizing the signal connection between the cable in the cable passage hole 201a, the receiving antenna assembly 1 and the inner cavity of the electronic instrument housing 7 through the wiring compartment 301. The water passage includes a first water passage 201c and a second water passage 201d. One end of the first water passage 201c extends axially along the head connector body 201 to the end face of the large section and communicates with the water passage inner hole of the front end receiving antenna assembly 1 of the outer tube 3. The other end extends radially along the head connector body 201 to the outer circle of the middle section and communicates with the water passage cavity. The second water passage 201d is located outside the first water passage 201c. The second water passage 201d is waist-shaped and directly penetrates both ends of the large section of the head connector body 201, thereby realizing radial and axial communication between the first water passage 201c and the second water passage 201d and the water passage cavity. The first rotating ring 203 includes a threaded section and a locking section. The threaded section is used for threaded connection with the electronic instrument housing 7. The locking section is provided with a fixing screw 204. The middle section of the head connector body 201 is provided with circumferentially distributed limiting grooves 201f. The fixing screw 204 is screwed into the limiting grooves 201f, thereby restricting the circumferential rotation of the first rotating ring 203 and preventing the threads from loosening. The locking section is provided with a flat square for using a tool to tighten the first rotating ring 203. The first half-ring 206 is provided with a screw 207. The small section of the head connector body 201 is provided with a screw hole. The first half-ring 206 is fixed to the head connector body 201 by the screw 207 engaging with the screw hole. There are two first half-rings 206, which are wrapped around and fixed to the head connector body 201, thereby achieving axial limiting and fixed connection of the first half-ring 206 to the first rotating ring 203. The head connector body 201 has two sets of seals 208 on its larger section, with the opening of the wire passage hole 201a located between the two sets of seals 208. The smaller section of the head connector body 201 also has seals 202, which are sealed to the electronic instrument housing 7, thus achieving multiple sealing connections between the head connector body 201, the outer tube 3, and the electronic instrument housing 7, preventing high-pressure water from entering the wire passage hole 201a. Multiple first water passage holes 201c are distributed circumferentially within the head connector body 201. The opening of the first water passage hole 201c on the middle section of the head connector body 201 is located between the first rotating ring 203 and the larger section, thus achieving multi-channel communication of the first water passage hole 201c and avoidance positioning of the first rotating ring 203.Both the first rotating ring 203 and the first half-ring 206 are fixed to the head connector body 201 by multiple circumferentially distributed screws 207, thereby achieving multi-point fixed connection of the first rotating ring 203 and the first half-ring 206 and improving the overall stability of the head assembly 2.

[0043] The second rotating ring 806 includes a threaded section and a locking section. The threaded section is used for threaded connection with the electronic instrument housing 7. The locking section is equipped with a screw 805. The middle section of the two-wing connector body 801 is provided with circumferentially distributed limiting grooves 801c. The screw 805 is screwed into the limiting grooves 801c, thereby limiting the circumferential rotation of the second rotating ring 806 and preventing the threads from loosening. The second half-ring 802 is equipped with a screw 803. The small section of the two-wing connector body 801 is provided with a screw hole. The second half-ring 802 is fixed to the two-wing connector body 801 by the screw 803 engaging with the screw hole. There are two second half-rings 802, which are fixed to the two-wing connector body 801, thereby achieving axial limiting and fixed connection of the second half-ring 802 to the second rotating ring 806. The positioning plane 801a and the two-wing flange 801b are in the same direction of the two-wing connector body 801, thereby achieving the cooperative positioning and limiting function of the positioning plane 801a and the two-wing flange 801b. The two-wing connector body 801 has transition connectors 808 and 809 in its large section. The transition connectors 808 and 809 are connected to the end of the transmission shaft 807 and are used to connect the transmission shaft 807 with the conventional MWD system for signal docking. The transition connector includes an outer connector and an inner connector. The outer connector is sealed to the two-wing connector body 801. The inner connector is located inside the outer connector and is connected to the transmission shaft 807. The outer connector is made of non-metallic material, while the inner connector and the transmission shaft 807 are made of metallic material, thereby achieving a sealed signal docking connection between the transmission shaft 807 and the conventional MWD system.

[0044] The electronic instrument housing 7 is equipped with a vibration damping sealing ring and a shock-absorbing pad for vibration damping of the receiving board assembly 4, battery assembly 5, and signal board assembly 6. The vibration damping sealing ring is located between the receiving board assembly 4 and the electronic instrument housing 7, the shock-absorbing pad is located at the bottom of the battery assembly 5, and the vibration damping sealing ring is located between the signal board assembly 6 and the electronic instrument housing 7. The shock-absorbing pad has a thickness of 2-5mm and fits precisely against the inner wall of the electronic instrument housing 7 with a gap of less than 0.3mm. The ends of the cable holes 201a and 201b are provided with tapered guide grooves with a cone angle of 20°-30° to facilitate cable insertion. There are 7 water holes 201c distributed circumferentially to further increase the water flow cross-sectional area.

[0045] The connection method for the downhole near-bit data receiver includes the following steps: The operator installs the first rotating ring 203 onto the head connector body 201 and uses the first baffle 205 and the first half-ring 206 for axial positioning; the head assembly 2 is sealed and connected to one end of the electronic instrument housing 7, and axial and circumferential positioning is achieved through the positioning plane, and the first rotating ring 203 is connected to the connecting thread 703 of the electronic instrument housing 7 through the thread, while the circumferential rotation of the first rotating ring 203 is restricted by screwing into the limiting groove; at the same time, the head assembly 2 is supported and placed into the outer tube 3, ensuring that the wire hole 201a is opposite to the wiring compartment 301 of the outer tube 3, and the water holes 201c and 201d are connected to the water cavity; The second rotating ring 806 is installed on the two-wing connector body 801 and axially limited by the second half ring 802 and the second baffle 804; the tail assembly 8 is sealed and connected to the other end of the electronic instrument housing 7, and axial and circumferential positioning and locking are achieved by the positioning plane and the two-wing flange 801b, and the thread of the second rotating ring 806 is connected to the connecting thread 704 of the electronic instrument housing 7, while the circumferential rotation is limited by screws screwed into the limiting groove; at the same time, the tail assembly 8 is supported and placed in the outer tube 3, and the transmission shaft 807 is connected to the conventional MWD signal, thereby realizing the signal transmission and water connection of the downhole near-bit data receiver.

[0046] The entire process requires no special tools; a standard wrench is all that's needed to connect or disconnect.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A sealed connection structure for a coal mine underground near-bit data receiver, characterised in that, The downhole near-bit data receiver comprises a head assembly, an electronic instrument housing and a tail assembly arranged in an outer pipe of a near-bit data receiving short section; the head assembly and the tail assembly are respectively sealed to two ends of the electronic instrument housing and are supported in the outer pipe through the head assembly and the tail assembly; Both ends of the inner hole of the electronic instrument housing are provided with stepped holes, and the stepped holes are provided with connecting threads; a flat square is arranged on the outer wall of the electronic instrument housing for tool to screw the connecting threads; The head assembly comprises a head joint body, a first rotating ring, a first baffle and a first half ring; the head joint body is arranged in the outer pipe, and the outer circle of the head joint body is stepped, comprising a large section, a middle section and a small section connected in sequence; the small section is provided with a positioning plane, and the electronic instrument housing is provided with a positioning plane matched with the positioning plane to realize axial and circumferential positioning of the head joint body and the electronic instrument housing; the outer circle of the large section is provided with a sealing element, and the sealing element is connected with the outer pipe in a sealed manner; the first rotating ring is rotatably sleeved on the middle section, the first rotating ring is provided with threads matched with the connecting threads of the electronic instrument housing, one end of the first rotating ring is in contact with the stepped end face of the head joint body, and the other end of the first rotating ring is provided with the first baffle and the first half ring; the first half ring is fixed on the small section, and the first baffle is used to axially position the first rotating ring, so as to realize threaded sealing connection and axial fixation of the head joint body and the electronic instrument housing; The tail assembly comprises a two-wing joint body, a second half ring, a second baffle and a second rotating ring; the two-wing joint body is provided with a transmission shaft penetrating in the axial direction; the transmission shaft is used for signal transmission; the outer circle of the two-wing joint body is stepped, comprising a large section, a middle section and a small section connected in sequence; the small section is provided with a positioning plane matched with the positioning plane on the electronic instrument housing to realize axial and circumferential positioning of the two-wing joint body and the electronic instrument housing; the large section is provided with a radially protruding two-wing flange matched with a groove arranged in the outer pipe to limit circumferential rotation of the two-wing joint body; the second rotating ring is rotatably sleeved on the middle section, the second rotating ring is provided with threads matched with the connecting threads of the electronic instrument housing, one end of the second rotating ring is in contact with the stepped end face of the two-wing joint body, and the other end of the second rotating ring is provided with the second baffle and the second half ring; the second half ring is fixed on the small section, and the second baffle is used to axially position the second rotating ring, so as to realize threaded sealing connection and axial fixation of the two-wing joint body and the electronic instrument housing, and the two-wing flange is connected with the outer pipe in a matched manner.

2. The sealed connection structure of a coal mine underground near-bit data receiver according to claim 1, characterized in that, The head joint body is internally provided with a wire passing hole and a water passing hole, a water passing cavity is formed between the electronic instrument shell and the outer tube, and the water passing hole is communicated with the water passing cavity; the head assembly is connected with the receiving antenna assembly of the near-bit data receiving sub by the wire cable in the wire passing hole, the tail assembly is connected with the conventional MWD through a transmission shaft, so that the signal connection between the head assembly and the receiving antenna assembly, the signal transmission between the tail assembly and the conventional MWD, and the water connection between the water passing hole and the water passing cavity are realized.

3. The sealed connection structure of an underground coal mine near-bit data receiver according to claim 2, characterized in that, One end of the wire passing hole extends axially along the head joint body to the end face of the small section and is communicated with the inner cavity of the electronic instrument shell, and the other end extends radially along the head joint body to the outer circle of the large section and is communicated with the wiring compartment on the outer tube, so that the wire cable in the wire passing hole is connected in signal with the receiving antenna assembly, the wiring compartment and the inner cavity of the electronic instrument shell.

4. The sealed connection structure of a near-bit data receiver in a coal mine underground according to claim 2, characterized in that, The water passing hole comprises a first water passing hole and a second water passing hole; one end of the first water passing hole extends axially along the head joint body to the end face of the large section and is communicated with the water passing inner hole of the receiving antenna assembly at the front end of the outer tube, and the other end extends radially along the head joint body to the outer circle of the middle section and is communicated with the water passing cavity; the second water passing hole is arranged outside the first water passing hole, the second water passing hole is in a waist shape and directly penetrates through the two end faces of the large section of the head joint body, so that the first water passing hole and the second water passing hole are radially and axially communicated with the water passing cavity.

5. The sealed connection structure of an underground coal mine near-bit data receiver according to claim 2, characterized in that, The first rotating ring comprises a threaded section and a locking section, the threaded section is used for threaded connection with the electronic instrument shell, and the locking section is provided with a screw; the middle section of the head joint body is provided with circumferentially distributed limiting grooves, and the screw is screwed into the limiting grooves, so as to limit the circumferential rotation of the first rotating ring, prevent the loosening of the thread, and realize the anti-loosening connection of the head joint body and the electronic instrument shell.

6. The sealed connection structure of an underground coal mine near-bit data receiver according to claim 5, characterized in that, The locking section is provided with a flat square, which is used for tool rotation of the first rotating ring, so as to facilitate the threaded connection operation of the first rotating ring and the electronic instrument shell.

7. The sealed connection structure of an underground coal mine near-bit data receiver according to claim 2, characterized in that, The first half ring is provided with a screw, the small section of the head joint body is provided with a screw hole, the first half ring is fixed to the head joint body through cooperation of the screw and the screw hole, and the first half ring is two, which is fixed around the head joint body, so as to realize the axial limiting and fixed connection of the first half ring to the first rotating ring.

8. The sealed connection structure of a near-bit data receiver in a coal mine underground according to claim 2, characterized in that, The sealing element on the large section of the head joint body has two groups, and the opening of the wire passing hole is located between the two groups of sealing elements; the small section of the head joint body is also provided with a sealing element, and the sealing element is sealingly connected with the electronic instrument shell, so as to realize the multiple sealing connection of the head joint body, the outer tube and the electronic instrument shell, and prevent high-pressure water from entering the wire passing hole.

9. The sealed connection structure of a near-bit data receiver in a coal mine underground according to claim 4, characterized in that, The first water passing holes are circumferentially distributed in the head joint body; the openings of the first water passing holes on the middle section of the head joint body are located between the first rotating ring and the large section, thereby realizing multi-channel communication of the first water passing holes and avoiding positioning of the first rotating ring.

10. The sealed connection structure of an underground coal mine near-bit data receiver according to claim 2, characterized in that, The first rotating ring and the first half ring are fixed to the head joint body by a plurality of circumferentially distributed screws, thereby realizing multi-point fixed connection of the first rotating ring and the first half ring and improving the overall stability of the head assembly.

11. The sealed connection structure for an underground coal mine near-bit data receiver according to claim 1, characterized in that, The second rotating ring includes a threaded section and a locking section; the threaded section is used for threaded connection with the electronic instrument shell; the locking section is provided with screws; the middle section of the two-wing joint body is provided with circumferentially distributed limiting grooves; the screws are screwed into the limiting grooves, thereby limiting the circumferential rotation of the second rotating ring, preventing loosening of the threads, and realizing anti-loosening connection of the two-wing joint body and the electronic instrument shell.

12. The sealed connection structure of an underground coal mine near-bit data receiver according to claim 11, characterized in that, The second half ring is provided with screws, and the small section of the two-wing joint body is provided with screw holes; the second half ring is fixed to the two-wing joint body by cooperation of the screws and the screw holes, and there are two second half rings, which are fixed around the two-wing joint body, thereby realizing axial limiting and fixed connection of the second half ring to the second rotating ring; the positioning plane and the two-wing flanges are in the same direction of the two-wing joint body, thereby realizing cooperative positioning and limiting of the positioning plane and the two-wing flanges.

13. The sealed connection structure for an underground coal mine near-bit data receiver, according to claim 11, wherein, The large section of the two-wing joint body is provided with a transition joint connected to the end of the transmission shaft, which is used for realizing signal connection of the transmission shaft and a conventional MWD system; the transition joint includes an outer joint and an inner joint; the outer joint is sealingly connected to the two-wing joint body; the inner joint is arranged in the outer joint and connected to the transmission shaft; the outer joint is made of a non-metallic material, and the inner joint and the transmission shaft are made of a metallic material, thereby realizing sealing signal connection of the transmission shaft and a conventional MWD.

14. A method of connecting a downhole near-bit data receiver as claimed in any one of claims 1 to 13, characterised in that, The method comprises the following steps: The first rotating ring is installed on the head joint body and axially limited by the first baffle and the first half ring; the head assembly is sealingly connected to one end of the electronic instrument shell, axially and circumferentially positioned by the positioning plane, and connected to the connection threads of the electronic instrument shell by the threads of the first rotating ring, while the circumferential rotation of the first rotating ring is limited by screwing the screws into the limiting grooves; at the same time, the head assembly is supported and placed into the outer pipe, ensuring that the wire passing hole is opposite to the wire storage of the outer pipe and the water passing hole is in communication with the water passing cavity. The first rotating ring is installed on the two-wing joint body and is axially limited by the second half ring and the second baffle; the tail assembly is sealingly connected to the other end of the electronic instrument shell, axially, circumferentially positioned and clamped and limited by the positioning plane and the two-wing flange, and connected by the threads of the second rotating ring and the connecting threads of the electronic instrument shell, while being circumferentially limited by screwing into the limiting groove; at the same time, the tail assembly is supported and placed into the outer pipe, the transmission shaft is connected to the conventional MWD signal, so that the signal transmission and water connection of the downhole near-bit data receiver are realized.

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