Gearbox of large-diameter drilling machine in underground coal mine

Abstract

The utility model belongs to the technical field of drilling machine transmission mechanism, concretely relates to a gear box of coal mine underground large aperture drilling machine, including the box, there are three parallel rotating shafts in the box, are input shaft, intermediate shaft and output shaft, are driven through gear between input shaft, intermediate shaft and output shaft, the output shaft is the hollow shaft, one end of output shaft is torque output part, the other end is the rotating waterway interface, one end of input shaft is torque input part, torque output part and torque input part are located the two sides of the box reverse, the outside of torque input part constructs the motor connection structure on the box, the outside of torque output part constructs the drill rod connector connection structure on the output shaft, the utility model discloses through the structure optimization has realized the technical target of big torque high -efficient transmission, strong sealing environment adaptation, high adaptation operation demand, has effectively solved the pain point of traditional gear box in the application in the large aperture drilling machine, has provided reliable transmission guarantee for the efficient implementation of the coal mine underground " with hole instead of lane " craft.

Description

Technical Field

[0001] This utility model belongs to the technical field of drilling rig transmission mechanism, specifically relating to a gearbox for a large-diameter drilling rig in coal mines. Background Technology

[0002] Large-diameter directional drilling rigs for coal mines are advanced drilling equipment used underground. They possess the capability for large-diameter drilling and controllable drilling trajectories, and are widely used in critical operations such as gas drainage, water hazard control, and geological exploration. Large-diameter drilling rigs operating in underground roadways aim to achieve Φ800mm holes in a single pass, realizing a "hole-for-roadway" process. By expanding the gas drainage channel area, they increase the drainage volume and concentration, thereby reducing the gas content in the coal seam.

[0003] However, the operating environment and construction requirements of large-diameter drilling rigs pose severe challenges to the core transmission components. To achieve one-time drilling of large-diameter boreholes, the drilling rig needs to drive the drill rod to operate continuously in complex coal seams and hard rock formations, and overcome huge resistances such as borehole wall friction and rock pressure. Therefore, the demand for driving torque is much higher than that of conventional small-diameter drilling rigs, and ultra-high torque needs to be output to ensure drilling penetration and continuity.

[0004] As the core transmission mechanism of large-diameter drilling rigs, the gearbox plays a crucial role in efficiently transmitting the torque from the power source to the drill rod and achieving speed-torque matching. Its performance directly determines the drilling rig's operating efficiency, stability, and service life. However, existing conventional gearboxes have significant shortcomings when adapting to large-diameter drilling rigs. In ultra-high torque transmission scenarios, problems such as insufficient gear meshing strength and shaft deformation are prone to occur, leading to decreased transmission efficiency or even component damage. Therefore, developing a gearbox that can adapt to high torque output, has high structural strength, and reliable sealing has become a key technical challenge in improving the performance of large-diameter drilling rigs in coal mines. Utility Model Content

[0005] This invention aims to solve the problem that existing gearboxes cannot match the ultra-high torque requirements of large-diameter drilling rigs.

[0006] This utility model provides the following technical solution: a gearbox for a large-diameter drilling rig in a coal mine, comprising a housing, three parallel rotating shafts inside the housing, namely an input shaft, an intermediate shaft, and an output shaft, which are connected by gear transmission; the output shaft is a hollow shaft, with one end being a torque output section and the other end being a rotary water interface; one end of the input shaft is a torque input section; the torque output section and the torque input section are located on opposite sides of the housing; a motor connection structure is constructed on the outside of the torque input section on the housing, and a drill rod connector connection structure is constructed on the outside of the torque output section on the output shaft.

[0007] Furthermore, a third gear is fitted in the middle of the output shaft, and the third gear and the output shaft are connected by a spline; tapered roller bearings and bushings are fitted on both sides of the third gear on the output shaft.

[0008] The bushing is fitted with a first end cover, which is bolted to the housing to enclose the tapered roller bearing. A rectangular sealing ring and two back-to-back skeleton seals are provided between the inside of the first end cover and the bushing, and a V-shaped sealing ring is provided between the outside of the first end cover and the bushing.

[0009] The torque input section of the output shaft is connected to a mounting ring via a thread. The mounting ring has bolt holes for connecting the drill pipe connector. A washer is placed between the mounting ring and the bushing. The washer axially restricts the bushing and V-shaped seal on the left side. The rotating water passage interface of the output shaft is connected to a second end cap via bolts. The second end cap axially restricts the bushing and V-shaped seal on the right side.

[0010] Furthermore, the intermediate shaft is fixed inside the housing, and a second gear is connected to the intermediate shaft via a cylindrical roller bearing.

[0011] Furthermore, one end of the input shaft is supported by a double-row self-aligning roller bearing inside the housing, and the other end is axially limited and radially supported by a positioning ring inside the housing. The input shaft is connected to a first gear via a key.

[0012] Furthermore, a centering step and bolt holes are constructed on the outside of the torque input section of the housing, and the centering step and bolt holes form the motor connection structure.

[0013] Furthermore, the torque input section at the end of the input shaft is an internal spline, and the torque input section is connected to the external spline on the motor shaft.

[0014] Furthermore, the torque output section at the end of the output shaft is an external spline, and the torque output section is connected to the internal spline on the drill pipe connector.

[0015] Furthermore, the housing has an oil filling hole, which is a stepped hole. The second step of the oil filling hole is fitted with a perforated sealing plate, and a sealing ring is provided between the sealing plate and the hole wall of the second step hole. The first step of the oil filling hole is fitted with an opening cover plate, and the opening cover plate and the hole on the sealing plate are connected. The opening cover plate is fixed to the sealing plate with screws, and the opening cover plate is fixed to the housing with screws. A plug is installed on the hole of the opening cover plate.

[0016] Compared with the prior art, the advantages of this utility model are:

[0017] This utility model provides a gearbox for a large-diameter drilling rig in coal mines, employing a gear transmission structure with three parallel shafts (input shaft, intermediate shaft, and output shaft). Power is transmitted step-by-step through gear meshing, optimizing the torque distribution path. The output shaft and the third gear are connected by a spline. The spline structure provides higher load-bearing capacity and centering accuracy, effectively distributing torque loads and preventing relative slippage or stress concentration between the gear and shaft. This ensures stable gear meshing even under extremely high torque output, solving the problems of easy loosening and low transmission efficiency associated with traditional connection methods. The input shaft is supported by double-row self-aligning roller bearings, which can automatically compensate for installation errors and shaft deformation, and avoid bearing jamming caused by downhole vibration or off-center loading. The output shaft is equipped with tapered roller bearings on both sides, providing high radial / axial stiffness to resist the huge reaction forces during rock drilling and reduce the impact of shaft deformation on gear meshing accuracy. The intermediate shaft floats and supports the second gear through cylindrical roller bearings, further dispersing meshing stress and improving the system's impact resistance. It can effectively resist shaft deformation during high torque transmission, ensuring long-term stable operation of the transmission system and meeting the ultra-high torque output requirements for Φ800mm single-hole drilling.

[0018] This utility model achieves the technical goals of high-efficiency transmission of high torque, strong sealing environment adaptability, and high adaptability to operational requirements through structural optimization. It effectively solves the pain points of traditional gearboxes in the application of large-diameter drilling rigs and provides a reliable transmission guarantee for the efficient implementation of the "hole-for-tunnel" process in underground coal mines. Attached Figure Description

[0019] Figure 1 A front view of the gearbox of a large-diameter drilling rig in an underground coal mine. Figure 1 ;

[0020] Figure 2 for Figure 1 Cross-sectional view at point AA;

[0021] Figure 3 This is a schematic diagram of the output shaft;

[0022] Figure 4 A front view of the gearbox of a large-diameter drilling rig in an underground coal mine. Figure 2 ;

[0023] Figure 5 for Figure 4 Cross-sectional view at point BB;

[0024] Figure 6 A schematic diagram of the gear transmission between the input shaft, intermediate shaft, and output shaft;

[0025] Figure 7 This is a schematic diagram of the oil filling hole on the housing.

[0026] In the diagram: 1-Box body; 1.1-Centering step; 1.2-Oil injection hole; 2-Input shaft; 3-Intermediate shaft; 4-Output shaft; 4.1-Torque output section; 4.2-Rotating water channel interface; 5-Tap roller bearing; 6-Third end cover; 7-Third gear; 8-Shaft sleeve; 9-First end cover; 10-Rectangular sealing ring; 11-Skeleton seal; 12-V-ring seal; 13-Mounting ring; 14-Washer; 15-Second end cover; 16-Cylindrical roller bearing; 17-Second gear; 18-Double row self-aligning roller bearing; 19-Positioning ring; 20-First gear; 21-Opening cover plate; 22-Plug; 23-Sealing plate. Detailed Implementation

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] like Figures 1-6 As shown: A gearbox for a large-diameter drilling rig in a coal mine includes a housing 1. Inside the housing 1 are three parallel rotating shafts: an input shaft 2, an intermediate shaft 3, and an output shaft 4. The input shaft 2, intermediate shaft 3, and output shaft 4 are connected by gear transmission. The output shaft 4 is the end of the entire transmission chain and is a hollow shaft. One end of the output shaft 4 is a torque output section 4.1, which efficiently transmits the high torque, amplified by the gearbox, to the drill rod, driving it to rotate and drill. The other end is a rotary water interface 4.2, connected to a water supply pipe via a rotary water seal device, allowing high-pressure cooling water to directly reach the drill bit through the internal channel of the hollow shaft, thus cooling the drill bit and lubricating the drill rod. One end of the input shaft 2 is a torque input section 2.1. The torque output section 4.1 and the torque input section 2.1 are located on opposite sides of the housing 1, forming a compact linear transmission layout. A motor connection structure is constructed on the outside of the torque input section 2.1 on the housing 1, and a drill rod connector connection structure is constructed on the outside of the torque output section 4.1 on the output shaft 4.

[0029] The torque input section 2.1 at the end of the input shaft 2 is an internal spline. The torque input section 2.1 is connected to the external spline on the motor shaft. The input shaft 2 receives the prime mover and large torque from the motor through the torque input section 2.1. The motor is a hydraulic motor.

[0030] The torque output section 4.1 at the end of the output shaft 4 is an external spline, and the torque output section 4.1 is connected to the internal spline on the drill pipe connector.

[0031] The spline structure has higher load-bearing capacity and centering accuracy, which can effectively distribute torque load, avoid stress concentration between shafts, and ensure stable gear meshing when outputting ultra-high torque.

[0032] The output shaft 4 is fitted with a third gear 7 in the middle, and the third gear 7 and the output shaft 4 are connected by a spline. Tapered roller bearings 5 ​​and bushings 8 are fitted on both sides of the third gear 7 on the output shaft 4. The tapered roller bearings 5 ​​can withstand huge radial and axial forces (from the thrust of drilling) at the same time, providing extremely high shaft rigidity, effectively resisting the reaction force during the rock drilling process, minimizing shaft deformation, and ensuring gear meshing accuracy and transmission efficiency.

[0033] A first end cover 9 is fitted onto the bushing 8. The first end cover 9 is bolted to the housing 1, enclosing the tapered roller bearing 5 inside. A rectangular sealing ring 10 and two back-to-back skeleton seals 11 are installed between the inside of the first end cover 9 and the bushing 8. A V-shaped sealing ring 12 is installed between the outside of the first end cover 9 and the bushing 8. The rectangular sealing ring 10 provides a static seal, preventing lubricating oil from leaking out of the housing. The back-to-back skeleton seals 11 form a tight dynamic seal, further preventing lubricating oil leakage and initially blocking the intrusion of external contaminants. The V-shaped sealing ring 12, with its excellent lip sealing performance and self-tightening characteristics, is specifically designed to prevent the intrusion of contaminants such as coal dust and mud from harsh external environments.

[0034] The torque input section 2.1 of the output shaft 4 is connected to a mounting ring 13 by a thread. The mounting ring 13 has bolt holes for connecting the drill pipe connector, which is used to securely connect the drill pipe connector and realize the efficient and reliable transmission of ultra-high torque to the drill pipe. A washer 14 is placed between the mounting ring 13 and the bushing 8. The washer 14 axially restricts the bushing 8 and the V-shaped seal ring 12 on the left side. The rotary water passage interface 4.2 of the output shaft 4 is connected to a second end cover 15 by bolts. The second end cover 15 axially restricts the bushing 8 and the V-shaped seal ring 12 on the right side.

[0035] The intermediate shaft 3 is fixed inside the housing 1. A second gear 17 is connected to the intermediate shaft 3 via a cylindrical roller bearing 16, allowing the second gear 17 to rotate freely while bearing radial loads.

[0036] One end of the input shaft 2 is supported by a double-row self-aligning roller bearing 18 inside the housing 1, and the other end is axially limited and radially supported by a positioning ring 19 inside the housing 1. The input shaft 2 is connected to a first gear 20 via a key. The axial displacement of the double-row self-aligning roller bearing 18 is limited by a third end cover 6 on the housing 1. The third end cover 6 and the housing 1 are connected by bolts.

[0037] The housing 1 has a centering step 1.1 and bolt holes on the outside of the torque input section 2.1. The centering step 1.1 and bolt holes form the motor connection structure. The motor housing is nested in the centering step 1.1 of the housing 1 and then locked with bolts. The fit between the motor housing and the centering step 1.1 of the housing 1 makes it difficult for the motor to run axially and radially. The positioning ring 19 at the end of the input shaft 2 only supports the input shaft 2 after the motor is disassembled. After the motor and housing 1 are combined, one end of the input shaft 2 is connected to the motor shaft through a spline, and the double-row self-aligning roller bearing 18 at the other end has a strong radial load capacity and self-aligning function, which can automatically compensate for slight misalignment of the shaft system caused by downhole vibration or installation error and prevent jamming.

[0038] The power flow path is: input shaft 2 > first gear 20 > second gear 17 > third gear 7 > output shaft 4. This three-stage gear transmission design effectively realizes torque splitting and speed conversion, significantly reduces the load on single-stage gear pairs, and lays the foundation for reliable transmission of ultra-high torque (meeting the drilling requirements of Φ800mm diameter holes).

[0039] like Figure 7 As shown: The housing 1 has an oil injection hole 1.2, which is a stepped hole. A perforated sealing plate 23 is installed in the second step of the oil injection hole 1.2. A sealing ring is set between the sealing plate 23 and the hole wall of the second step hole to form a leak-proof barrier. An opening cover plate 21 is installed in the first step of the oil injection hole 1.2. The holes on the opening cover plate 21 and the sealing plate 23 are connected. The opening cover plate 21 is fixed to the sealing plate 23 with screws to form a stable and easy-to-disassemble structure. The opening cover plate 21 is fixed to the housing 1 with screws. A plug 22 is installed on the hole of the opening cover plate 21. The plug 22 and the opening cover plate 21 are connected by threads. The easy-to-disassemble design of the plug 22 and the opening cover plate 21 makes the lubrication and maintenance operation simple and quick, which is suitable for the operation requirements of the confined space downhole. After the opening cover plate 21 and the sealing plate 23 are disassembled as a whole, it is easy to discharge the waste oil and metal shavings generated by the gearbox operation inside the housing.

[0040] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gearbox for a large-diameter drilling rig in a coal mine, characterized in that: The housing (1) contains three parallel rotating shafts: an input shaft (2), an intermediate shaft (3), and an output shaft (4). The input shaft (2), intermediate shaft (3), and output shaft (4) are connected by gear transmission. The output shaft (4) is a hollow shaft with a torque output section (4.1) at one end and a rotating water channel interface (4.2) at the other end. One end of the input shaft (2) is a torque input section (2.1). The torque output section (4.1) and the torque input section (2.1) are located on opposite sides of the housing (1). A motor connection structure is constructed on the outside of the torque input section (2.1) on the housing (1), and a drill pipe connector connection structure is constructed on the outside of the torque output section (4.1) on the output shaft (4).

2. The gearbox of a large-diameter underground drilling rig in a coal mine according to claim 1, characterized in that: The output shaft (4) is fitted with a third gear (7) in the middle, and the third gear (7) and the output shaft (4) are connected by a spline; tapered roller bearings (5) and bushings (8) are fitted on both sides of the third gear (7) on the output shaft (4). The bushing (8) is fitted with a first end cover (9). The first end cover (9) and the housing (1) are connected by bolts to enclose the tapered roller bearing (5). A rectangular sealing ring (10) and two back-to-back skeleton seals (11) are provided between the inside of the first end cover (9) and the bushing (8). A V-shaped sealing ring (12) is provided between the outside of the first end cover (9) and the bushing (8). A mounting ring (13) is threadedly connected to one side of the torque input section (2.1) of the output shaft (4). Bolt holes for connecting the drill pipe connector are distributed on the mounting ring (13). A washer (14) is placed between the mounting ring (13) and the bushing (8). The washer (14) axially restricts the bushing (8) and the V-shaped seal (12) on the left side. A second end cap (15) is bolted to one side of the rotary water interface (4.2) of the output shaft (4). The second end cap (15) axially restricts the bushing (8) and the V-shaped seal (12) on the right side.

3. The gearbox of a large-diameter underground drilling rig in a coal mine according to claim 2, characterized in that: The intermediate shaft (3) is fixed inside the housing (1), and a second gear (17) is connected to the intermediate shaft (3) via a cylindrical roller bearing (16).

4. The gearbox of a large-diameter underground drilling rig in a coal mine according to claim 3, characterized in that: One end of the input shaft (2) is supported by a double-row self-aligning roller bearing (18) in the housing (1), and the other end is axially limited and radially supported by a positioning ring (19) in the housing (1). The input shaft (2) is connected to a first gear (20) via a key.

5. The gearbox of a large-diameter underground drilling rig in a coal mine according to claim 4, characterized in that: The housing (1) has a centering step (1.1) and bolt holes on the outside of the torque input part (2.1), and the centering step (1.1) and bolt holes form a motor connection structure.

6. The gearbox of a large-diameter underground drilling rig in a coal mine according to claim 1, characterized in that: The torque input section (2.1) at the end of the input shaft (2) is an internal spline, and the torque input section (2.1) is connected to the external spline on the motor shaft.

7. The gearbox of a large-diameter underground drilling rig in a coal mine according to claim 1, characterized in that: The torque output section (4.1) at the end of the output shaft (4) is an external spline, and the torque output section (4.1) is connected to the internal spline on the drill pipe connector.

8. A gearbox for a large-diameter underground drilling rig in a coal mine according to any one of claims 1 to 7, characterized in that: The housing (1) has an oil injection hole (1.2), which is a stepped hole. A perforated sealing plate (23) is installed in the second step of the oil injection hole (1.2). A sealing ring is provided between the sealing plate (23) and the hole wall of the second step hole. An opening cover plate (21) is installed in the first step of the oil injection hole (1.2). The opening cover plate (21) and the hole on the sealing plate (23) are connected. The opening cover plate (21) is fixed to the sealing plate (23) by screws. The opening cover plate (21) is fixed to the housing (1) by screws. A plug (22) is installed on the hole of the opening cover plate (21).

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