Directional drilling rig power head

Abstract

A directional drilling rig power head, relating to the technical field of coal mine drilling rigs. The directional drilling rig power head comprises a main motor (1), a transmission (2), a main shaft (10), a driving drill pipe (6), and a water braid (4). The transmission is provided with a driving shaft (201), one end of the driving shaft is connected to the main motor, the driving shaft is in meshing transmission with the main shaft by means of a gear in the transmission, one end of the main shaft is fixedly connected to the driving drill pipe in the circumferential direction, and the other end of the driving shaft is connected to an angle adjuster (3) by means of the transmission, so that the directional drilling rig power head has the functions of efficiently and accurately adjusting the tool face and braking the main motor. A mandrel (402) in the water braid is connected to, by means of a connecting shaft (7), the driving drill pipe having an axial floating structure, and the end of the main shaft close to the water braid is provided with a connecting sleeve (8) forming a hexagonal sleeve sliding pair together with the connecting shaft, so that a mandrel supporting bearing (401) is free from axial impact in the drilling process, thereby prolonging the service life and reducing the number of times of device maintenance.

Description

Directional drilling rig power head Technical Field

[0001] The invention belongs to the technical field of coal mine drilling rigs and relates to a directional drilling rig power head. Background Art

[0002] During directional drilling, tool face angle adjustment is often required to change the direction of the drilling trajectory. Existing directional drill heads are essentially the same as traditional drill heads and lack a device for accurately controlling the rotation angle. Tool face angle adjustment relies on a rotary drilling motor, which rotates rapidly. This, combined with the high inertia of the power head's transmission system, results in poor control accuracy and inefficient adjustment. Existing directional drills typically have only one (or a set of) motors: the main motor that drives the main shaft. Therefore, tool face angle adjustment also relies on this main motor. During drilling, multiple drill rods are inevitably threaded together within the hole. Therefore, tool face angle adjustment can only be achieved by using the main motor to drive the main shaft and drill rods in the forward direction. Reverse rotation could potentially loosen the threaded connections within the hole, leading to drill loss. Due to the required drilling speed in coal mines, the main motor drives the drill rod at a relatively high speed, even at low speeds of approximately 50 rpm (300° / s). Consequently, the adjustment accuracy of this system is very low. In addition, the power head transmission system (spindle, gears, etc.) has a large mass and inertia, and often cannot stop accurately when the tool face angle is adjusted. Once the preset angle is missed, it must be rotated forward for about one circle and readjusted, and repeated over and over again, resulting in very low adjustment efficiency and lack of accuracy.

[0003] Secondly, during the directional drilling process, the water braid is one of the essential accessories for directional drilling rig construction. It serves as a connection between the drilling rig and the external pressure medium, and supplies the pressure fluid required for drilling and slag removal to the drill pipe and drill bit. The water braid of existing drilling rigs is generally independent of other components and is installed in isolation at the end of the last drill pipe of the power head main shaft. The water braid usually includes a core shaft, a water inlet assembly mounted on the core shaft, a bearing seat mounted on the core shaft, an end cover detachably connected to the bearing seat, and a rear cover detachably connected to the end cover. A bearing is provided between the bearing seat and the core shaft, and the water braid is then directly installed in isolation at the end of the last drill pipe of the power head main shaft through the core shaft. Because the water braid of existing drilling rigs is generally independent of other components and is installed in isolation at the end of the last drill pipe of the power head main shaft, the water braid of existing drilling rigs is subjected to uneven axial hydraulic pressure. In addition, without other force transmission structures, the water braid is subjected to axial hydraulic shock and drilling vibration shock during drilling. The core shaft support bearing of the core shaft is very easily damaged, requiring frequent maintenance, which seriously affects construction efficiency.

[0004] The Chinese patent with publication number CN103061669B is a typical representative of the existing technology. It discloses a large through-hole power head of a coal mine underground directional drilling rig with a braking function. The key is that it includes a motor, a gearbox, a main shaft, a shaft I, and a chuck. The motor is connected to the main shaft through the gearbox. The shaft I is engaged with the main shaft through the gear in the gearbox. The chuck is arranged at the front end of the main shaft. A support ring is installed at the rear end of the main shaft. An oil sleeve is set on the main shaft. The shaft I is connected to a brake through the gearbox. The brake adopts a wet friction disc structure. The brake dial is connected to the shaft I of the power head through a spline. The active friction plate is connected to the main shaft. The fork claw of the dial is connected, and the passive friction plate is connected to the end cap shaft fixed to the brake end cap via a spline. The brake is provided with a piston rod, which is evenly distributed around the piston rod. The front end of the piston rod is provided with a pressure plate, and the front end of the pressure plate is provided with six active friction plates and five passive friction plates arranged in a stacked manner. The rear end of the piston rod presses against the front end of the end cap shaft. A pressure cap is installed in the slot at the front end of the end cap shaft, and the bottom of the pressure cap is provided with a shaft end spring. A locking nut is provided at the front end of the end cap shaft. The oil drain port of the motor is connected to the lower oil port of the brake housing, and the oil flows back to the oil tank through the upper oil port of the brake housing. The piston rod spring and the piston rod are tightly matched. This enables the large through-hole power head of the coal mine underground directional drilling rig to have a spindle braking function and meet both rotary drilling and bottom-hole motor directional drilling processes. However, the large through-hole power head of the coal mine underground directional drilling rig does not have a device that can accurately control the tool face angle rotation angle. The spindle motor is still required to adjust the tool face angle rotation angle, so the tool face angle cannot be accurately adjusted; secondly, its brake device has a single function. Not only does it not have an angle adjustment function, but it also uses a traditional friction plate method, with many internal wearing parts, which requires frequent replacement of parts and maintenance, making maintenance during later operation more difficult.

[0005] Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a directional drilling rig power head to solve the problem that the tool face angle cannot be accurately adjusted in the existing directional drilling process and the problem that the core shaft support bearing in the water braid is easily damaged due to axial hydraulic impact and drilling vibration impact during drilling.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A directional drilling rig power head includes a main motor, a transmission, and a main shaft. The transmission has a drive shaft, one end of which is connected to the main motor. The drive shaft is meshed with the main shaft through gears in the transmission. The key point is that the other end of the drive shaft is connected to an angle adjuster through the transmission.

[0009] The angle adjuster includes a transmission shaft, a fixed gear plate, a movable gear plate, a slewing seat and a slewing reducer with a self-locking function, one end of the transmission shaft is circumferentially fixedly connected to the drive shaft, the fixed gear plate and the movable gear plate are both sleeved on the transmission shaft, and the fixed gear plate and the movable gear plate are engaged with each other in a helical gear, the fixed gear plate and the transmission shaft are circumferentially fixedly connected, the movable gear plate and the transmission shaft are rotatably connected, and the movable gear plate can slide along the axial direction of the transmission shaft;

[0010] The rotary seat is sleeved on the movable gear disc and is fixedly connected in the circumferential direction. The output disc of the rotary reducer is coaxial with the rotary seat and is fixedly connected to the movable gear disc so as to transmit the rotation of the output disc of the rotary reducer to the movable gear disc.

[0011] Furthermore, the angle adjuster further comprises a driving piston and a connecting seat, wherein the driving piston is sleeved on the driving shaft and is located on a side of the fixed gear disc away from the movable gear disc, and an end of the driving piston away from the driving shaft is connected to the movable gear disc;

[0012] The connecting seat is sleeved on the driving piston. The outer diameter of the connecting seat is divided into three levels of diameter, and the diameter of the middle section is the largest. The end faces of both sides of the middle section are respectively connected to the transmission and the rotary reducer to achieve relative axial positioning between the transmission, the connecting seat and the rotary reducer. The inner diameter of the connecting seat is divided into three levels of aperture, among which the two sections of aperture away from the transmission match the outer diameter of the driving piston and are sleeved on the driving piston.

[0013] The driving piston is a two-stage stepped shaft, and a sealing groove is provided on the outer circle of its small diameter end. A sealing ring is installed in the sealing groove and cooperates with the corresponding position of the connecting seat mounted thereon to form a first seal. The outer circle of the large diameter end cooperates with the sealing ring installed at the corresponding position of the connecting seat to form a second seal. A sealed cavity is formed between the driving piston and the connecting seat between the first seal and the second seal, and an oil inlet connected to the sealed cavity is provided on the connecting seat. Under the action of hydraulic oil entering the sealed cavity through the oil inlet, the driving piston pushes the movable gear disc in the direction away from the fixed gear disc, so that the movable gear disc can slide along the axial direction of the transmission shaft.

[0014] Furthermore, the angle adjuster also includes an angle adjuster end cover, the other end of the transmission shaft is rotatably connected to the angle adjuster end cover, the movable gear disc is a disc-shaped part with a central through hole, and the central through hole is a stepped through hole, and the stepped through hole is a large-diameter through hole facing the angle adjuster end cover, the movable gear disc is sleeved on the angle adjuster end cover through the large-diameter through hole and slidably connected, the end surface of the movable gear disc facing the driving piston is provided with first helical teeth distributed along the circumference, and the fixed gear disc is provided with second helical teeth meshing with the first helical teeth, and a spring is provided between the inner end surface of the large-diameter through hole and the end surface of the angle adjuster end cover opposite to the inner end surface, so that the first helical teeth and the second helical teeth are meshed under the thrust of the spring;

[0015] The outer circumferential surface of the movable gear disc is provided with evenly distributed bosses, the rotary seat is sleeved on the movable gear disc and is provided with grooves matching the bosses so as to be fixedly connected to the movable gear disc in the circumferential direction, and one end of the rotary seat is provided with a rotary reducer connecting plate fixedly connected to the output plate of the rotary reducer so as to transmit the rotation of the output plate in the rotary reducer to the movable gear disc.

[0016] Furthermore, a transmission piston is provided between the driving piston and the movable gear disc. The transmission piston is sleeved on the transmission shaft and slidably connected. One end of the transmission piston is connected to the driving piston, and the other end is connected to the movable gear disc to transmit the thrust of the driving piston.

[0017] Furthermore, the slewing seat is cylindrical, and an end portion thereof away from the slewing reducer connecting disk is provided with an end cover connecting disk for fixed connection with the angle adjuster end cover.

[0018] Furthermore, the fixed gear disc has a gear disc and a fixed shaft located at the center of the gear disc, the second bevel teeth are arranged on the gear disc, the fixed shaft is inserted into the central through hole of the movable gear disc, and a keyway is provided in the fixed shaft so that the fixed gear disc is circumferentially fixedly connected to the transmission shaft through a key connection.

[0019] Furthermore, the angle adjuster end cover is a three-step stepped hollow disc structure, which is mounted on the transmission shaft through a bearing sleeve. Its maximum outer diameter section is provided with a flange connected to the swivel seat, and the maximum outer diameter section is located at the end away from the drive shaft. The middle diameter section is used to support the swivel seat and limit the axial movement distance of the movable gear disc. The minimum diameter section is axially slidably connected to the large diameter through hole of the movable gear disc, and the end face of the minimum diameter section is provided with a plurality of spring mounting holes evenly distributed along the circumference for installing springs.

[0020] Furthermore, the drive shaft is arranged in the transmission, one side end face of the middle section in the connecting seat is connected to the transmission, a section of the connecting seat close to the transmission is inserted into the transmission and serves as an axial stop for the bearing sleeved on the drive shaft, and a section close to the rotary reducer extends toward the interior of the rotary reducer to serve as a guide for the installation of the rotary reducer.

[0021] A directional drilling rig power head includes a main motor, a transmission, a main shaft, an active drill pipe, and a water braid. The main motor is connected to the main shaft through the transmission. One end of the main shaft is circumferentially fixedly connected to the active drill pipe. The key point is that it also includes a connecting shaft and a connecting sleeve. The water braid includes a core shaft, a water inlet assembly, a bearing seat, a sealing shaft, and a core shaft support bearing. The water inlet assembly is sleeved on the core shaft and rotatably connected. The bearing seat is sleeved on the core shaft through the core shaft support bearings provided at both ends of the bearing seat and rotatably connected.

[0022] The core shaft is a hollow shaft, the left end of which is fixedly connected to the connecting shaft, and the inner side of the right end of which is connected to the sealing shaft to seal the right end of the core shaft, and a water inlet hole is provided on the core shaft, and the water inlet hole is connected to the water inlet assembly, and the water inlet assembly includes a water inlet and a shell connected to the water inlet, the inner cavity of the shell is a symmetrical structure, and the symmetry plane is perpendicular to the axis of the core shaft to balance the axial force thereof, the water inlet assembly is sleeved on the core shaft through the shell, and the inner cavity of the shell is connected to the water inlet hole of the core shaft;

[0023] The connecting shaft is a hollow shaft and is arranged inside the main shaft. Its two ends are respectively connected to the core shaft and the active drill rod with an axial floating structure, and a hexagonal head is provided at the end of the connecting shaft close to the core shaft. The connecting sleeve is fixedly connected to the end of the main shaft close to the water braid and is sleeved on the connecting shaft. A hexagonal hole matching the hexagonal head is provided inside the connecting sleeve to form a sliding connection between the connecting shaft and the connecting sleeve to limit rotation, thereby allowing the connecting shaft and the core shaft to have axial floating.

[0024] Furthermore, the directional drilling rig power head also includes a chuck, which is connected to the end of the main shaft away from the water braid and rotates with the main shaft. The axial floating structure of the active drill rod includes a spring and a drill rod end cover. The active drill rod and the chuck are keyed so that the main shaft and the active drill rod are fixedly connected circumferentially, and the spring is arranged on the end face of the active drill rod close to the chuck so that the active drill rod can float axially. The drill rod end cover is sleeved on the active drill rod and fixedly connected to the chuck to limit the axial floating distance of the active drill rod.

[0025] Furthermore, assuming that the maximum distance between the end face of the active drill rod close to the chuck and the end face of the chuck corresponding thereto is a, and the pitch of the threads of the active drill rod and the drill rod joint connected thereto is p, a≤p.

[0026] Furthermore, the hexagonal head of the connecting shaft and its middle cylindrical section form multiple evenly distributed axial stop end faces, and the stop end faces match the end face of the connecting sleeve close to the connecting shaft. Assuming that when the active drill rod floats axially to the leftmost end, the distance between the stop end face and the end face of the connecting sleeve close to the connecting shaft is b, then b>a.

[0027] Furthermore, the core shaft and the connecting shaft are fixedly connected via threads, and the threads of the core shaft are external threads, while the threads of the connecting shaft are internal threads.

[0028] Furthermore, a cover plate is fixedly connected to the right end of the core shaft to axially fix the sealing shaft.

[0029] A directional drilling rig power head includes a main motor, a transmission, a main shaft, an active drill rod, and a water braid. The transmission has a drive shaft, one end of which is connected to the main motor. The drive shaft is meshed with the main shaft through gears in the transmission. One end of the main shaft is circumferentially fixedly connected to the active drill rod. The key point is that the other end of the drive shaft is connected to an angle adjuster through the transmission.

[0030] The angle adjuster includes a transmission shaft, a fixed gear plate, a movable gear plate, a slewing seat and a slewing reducer with a self-locking function, one end of the transmission shaft is circumferentially fixedly connected to the drive shaft, the fixed gear plate and the movable gear plate are both sleeved on the transmission shaft, and the fixed gear plate and the movable gear plate are engaged with each other in a helical gear, the fixed gear plate and the transmission shaft are circumferentially fixedly connected, the movable gear plate and the transmission shaft are rotatably connected, and the movable gear plate can slide along the axial direction of the transmission shaft;

[0031] The rotary seat is sleeved on the movable gear disc and is circumferentially fixedly connected, and the output disc of the rotary reducer is coaxial with and fixedly connected to the rotary rotary seat to transmit the rotation of the output disc of the rotary reducer to the movable gear disc;

[0032] The directional drilling rig power head also includes a connecting shaft and a connecting sleeve. The water braid includes a core shaft, a water inlet assembly, a bearing seat, a sealing shaft and a core shaft support bearing. The water inlet assembly is sleeved on the core shaft and rotatably connected. The bearing seat is sleeved on the core shaft and rotatably connected through the core shaft support bearings provided at both ends of the bearing seat.

[0033] The core shaft is a hollow shaft, the left end of which is fixedly connected to the connecting shaft, and the inner side of the right end of which is connected to the sealing shaft to seal the right end of the core shaft, and a water inlet hole is provided on the core shaft, and the water inlet hole is connected to the water inlet assembly, and the water inlet assembly includes a water inlet and a shell connected to the water inlet, the inner cavity of the shell is a symmetrical structure, and the symmetry plane is perpendicular to the axis of the core shaft to balance the axial force thereof, the water inlet assembly is sleeved on the core shaft through the shell, and the inner cavity of the shell is connected to the water inlet hole of the core shaft;

[0034] The connecting shaft is a hollow shaft and is arranged inside the main shaft. Its two ends are respectively connected to the core shaft and the active drill rod with an axial floating structure, and a hexagonal head is provided at the end of the connecting shaft close to the core shaft. The connecting sleeve is fixedly connected to the end of the main shaft close to the water braid and is sleeved on the connecting shaft. A hexagonal hole matching the hexagonal head is provided inside the connecting sleeve to form a sliding connection between the connecting shaft and the connecting sleeve to limit rotation, thereby allowing the connecting shaft and the core shaft to have axial floating.

[0035] Furthermore, the angle adjuster further comprises a driving piston and a connecting seat, wherein the driving piston is sleeved on the driving shaft and is located on a side of the fixed gear disc away from the movable gear disc, and an end of the driving piston away from the driving shaft is connected to the movable gear disc;

[0036] The connecting seat is sleeved on the driving piston. The outer diameter of the connecting seat is divided into three levels of diameter, and the diameter of the middle section is the largest. The end faces of both sides of the middle section are respectively connected to the transmission and the rotary reducer to achieve relative axial positioning between the transmission, the connecting seat and the rotary reducer. The inner diameter of the connecting seat is divided into three levels of aperture, among which the two sections of aperture away from the transmission match the outer diameter of the driving piston and are sleeved on the driving piston.

[0037] The driving piston is a two-stage stepped shaft, and a sealing groove is provided on the outer circle of its small diameter end. A sealing ring is installed in the sealing groove and cooperates with the corresponding position of the connecting seat mounted thereon to form a first seal. The outer circle of the large diameter end cooperates with the sealing ring installed at the corresponding position of the connecting seat to form a second seal. A sealed cavity is formed between the driving piston and the connecting seat between the first seal and the second seal, and an oil inlet connected to the sealed cavity is provided on the connecting seat. Under the action of hydraulic oil entering the sealed cavity through the oil inlet, the driving piston pushes the movable gear disc in the direction away from the fixed gear disc, so that the movable gear disc can slide along the axial direction of the transmission shaft.

[0038] Furthermore, the angle adjuster also includes an angle adjuster end cover, the other end of the transmission shaft is rotatably connected to the angle adjuster end cover, the movable gear disc is a disc-shaped part with a central through hole, and the central through hole is a stepped through hole, and the stepped through hole is a large-diameter through hole facing the angle adjuster end cover, the movable gear disc is sleeved on the angle adjuster end cover through the large-diameter through hole and slidably connected, the end surface of the movable gear disc facing the driving piston is provided with first helical teeth distributed along the circumference, and the fixed gear disc is provided with second helical teeth meshing with the first helical teeth, and a spring is provided between the inner end surface of the large-diameter through hole and the end surface of the angle adjuster end cover opposite to the inner end surface, so that the first helical teeth and the second helical teeth are meshed under the thrust of the spring;

[0039] The outer circumferential surface of the movable gear disc is provided with evenly distributed bosses, the rotary seat is sleeved on the movable gear disc and is provided with grooves matching the bosses so as to be fixedly connected to the movable gear disc in the circumferential direction, and one end of the rotary seat is provided with a rotary reducer connecting plate fixedly connected to the output plate of the rotary reducer so as to transmit the rotation of the output plate in the rotary reducer to the movable gear disc.

[0040] The beneficial effects of the present invention are:

[0041] 1. The present invention provides a directional drilling rig power head. By improving the power head structure, an angle adjuster is provided on the side of the transmission away from the main motor. The transmission shaft in the angle adjuster is circumferentially fixedly connected to the drive shaft. The angle adjuster, which has accurate angle adjustment and anti-rotation locking functions, not only achieves accurate and efficient adjustment of the tool face angle, but also prevents rebound rotation of the power head spindle caused by elastic deformation of the drill pipe. This solves the problem of the existing drilling rig lacking a dedicated tool face angle adjustment device, resulting in low trajectory adjustment accuracy and efficiency, and difficulty in achieving automatic directional drilling.

[0042] At the same time, the driving force required for tool face angle adjustment is greatly reduced, which has a good energy-saving effect, simplifies the structure of the main motor's rotary brake device, and converts the functions of a large number of internal parts into an external rotary reducer, which greatly reduces the difficulty of maintenance and reduces the consumption of wearing parts.

[0043] 2. The present invention integrates the water braid and the active drill rod through a connecting shaft, thereby avoiding manual loading and unloading of the water braid during construction and being more suitable for intelligent drilling rigs. The water inlet assembly in the water braid adopts a shell symmetrical along the middle plane to connect with the core shaft, so that it is subjected to balanced force in the axial direction of the core shaft, thereby avoiding unbalanced force on the core shaft support bearing caused by the drilling drive medium entering the core shaft, and the core shaft is connected to the active drill rod with an axial floating structure through the connecting shaft, which effectively avoids the water braid from being subjected to axial impact from the drill rod during drilling. Instead, the water braid is transmitted to the main shaft and chuck through the active drill rod, and is buffered by the spring, further protecting the core shaft support bearing from axial impact, thereby improving its service life and reducing the number of equipment maintenance times.

[0044] 3. The present invention adopts a drill rod connection device that combines an active drill rod and a chuck, which can achieve rapid switching between drilling and fishing drill rod working conditions by disassembling a small number of parts.

[0045] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0047] FIG1 is a schematic structural diagram of a directional drilling rig power head in the invention;

[0048] FIG2 is a schematic cross-sectional view of a directional drilling rig power head according to the present invention;

[0049] FIG3 is a schematic structural diagram of the angle adjuster in the present invention;

[0050] FIG4 is a schematic structural diagram of a driving piston of an angle adjuster in the present invention;

[0051] FIG5 is a schematic structural diagram of a movable toothed disc of an angle adjuster in the present invention;

[0052] FIG6 is a schematic structural diagram of a fixed toothed disc of an angle adjuster according to the present invention;

[0053] FIG7 is a schematic structural diagram of the end cover of the angle adjuster in the present invention;

[0054] FIG8 is a schematic structural diagram of a rotary seat of an angle adjuster in the present invention;

[0055] FIG9 is a partial enlarged structural diagram of the angle adjuster in the present invention;

[0056] FIG10 is a schematic diagram of the structure of the water braid in the present invention;

[0057] FIG11 is a schematic structural diagram of the connecting shaft in the present invention.

[0058] Figure markings: 1-main motor, 2-transmission, 201-drive shaft, 3-angle adjuster, 301-transmission shaft, 302-drive piston, 302a-sealing groove, 302b-large diameter end outer circle, 303-rotary reducer, 304-transmission piston, 305-fixed gear plate, 305a-gear plate, 305b-fixed shaft, 306-movable gear plate, 306a-boss, 306b-first oblique tooth, 307-angle adjuster end cover, 307a-maximum outer diameter section, 307b-intermediate diameter section, 307c-minimum outer diameter section, 307d-spring mounting hole, 308-shaft Pressure cover, 309-spring, 310-slewing seat, 310a-slewing reducer connecting plate, 310b-end cover connecting plate, 310c-groove, 311-flat key, 4-water braid, 401-core shaft support bearing, 402-core shaft, 403-water inlet assembly, 404-bearing seat, 405-grease nipple, 406-distance sleeve, 407-water braid end cover, 408-cover plate, 409-sealing shaft, 5-chuck, 6-active drill rod, 7-connecting shaft, 701-external thread, 702-hexagonal head, 703-internal thread, 8-connecting sleeve, 9-connecting seat, 10-spindle, Y-sealing chamber. DETAILED DESCRIPTION

[0059] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways 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 illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0060] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0061] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships 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 direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0062] Please refer to Figures 1 to 11, which show a directional drilling rig power head, including a main motor 1, a transmission 2, an angle adjuster 3, a water braid 4, a chuck 5, a main shaft 10, a connecting shaft 7, a connecting sleeve 8 and an active drill rod 6. The main motor 1 is connected to the main shaft 10 through the transmission 2, and the active drill rod 6 is connected to one end of the main shaft 10 through the chuck 5. The water braid 4 is arranged at the end of the transmission 2 corresponding to the active drill rod 6, and is connected to the active drill rod 6 through the connecting shaft 7 built into the main shaft 10. The angle adjuster 3 is arranged at the end of the transmission 2 corresponding to the main motor 1, and the transmission shaft 301 in the angle adjuster 3 is fixedly connected circumferentially with the drive shaft 201 in the transmission 2.

[0063] The main motor 1 is one of the power sources that drives the active drill rod 6. The rotational power required for rotary drilling, combined drilling, and drill rod connection and breakout all comes from the main motor 1. The main motor 1 can be any of a variety of rotary power drive devices, such as a hydraulic motor, an electric motor, or other power drive devices. Due to the complex working conditions and explosion-proof requirements of coal mines, the main motor 1 in this embodiment is preferably a hydraulic motor.

[0064] The transmission 2 is a speed-changing transmission mechanism of the directional drilling rig power head, which mainly transmits the speed and torque output by the main motor 1 and the angle adjuster 3 to the main shaft 10 (i.e., to the drill rod) at a certain transmission ratio, thereby meeting the requirements of drilling and drill rod connection and disconnection. According to existing hydraulic motor technology and drilling requirements, the transmission 2 generally selects a transmission with speed reduction and torque increase transmission functions. The transmission 2 has a drive shaft 201, and one end of the drive shaft 201 is spline-connected to the output shaft of the main motor 1 to achieve a circumferential fixed connection, and the other end is spline-connected to the transmission shaft 301 in the angle adjuster 3 to achieve a circumferential fixed connection, thereby transmitting the speed and torque output by the main motor 1 and the angle adjuster 3 to the main shaft 10 and the active drill rod 6 at a certain transmission ratio, thereby meeting the requirements of directional drilling and drill rod connection and disconnection.

[0065] The angle adjuster 3 includes a transmission shaft 301, a slewing seat 310, a connecting seat 9, a bearing cover 308, a spring 309, a driving piston 302, a transmission piston 304, a fixed gear plate 305, a movable gear plate 306 and an angle adjuster end cover 307 which are sequentially sleeved on the transmission shaft 301 from left to right, and a slewing reducer 303 with a self-locking function, and the transmission ratio of the slewing reducer 303 is greater than the transmission ratio of the transmission 2; the left end of the transmission shaft 301 is a spline, which is inserted into the drive shaft 201 of the transmission 2, and the drive shaft 201 is provided with a keyway that matches the spline on the transmission shaft 301, so that the transmission shaft 301 forms a self-locking reducer with the drive shaft 201. A spline connection is formed to form a circumferential fixed connection; the right end of the transmission shaft 301 is connected to the fixed gear disc 305 sleeved on the transmission shaft 301 through a flat key 311 to form a circumferential fixed connection, and is rotatably connected to the angle adjuster end cover 307 through a bearing, and the angle adjuster end cover 307 is located on the side of the fixed gear disc 305 away from the drive shaft 201, that is, on the right side of the fixed gear disc 305, and a distance sleeve 406 is provided on both sides of the bearing, and a bearing pressure cover 308 is provided on the side of the angle adjuster end cover 307 away from the fixed gear disc 305, which is fixed to the angle adjuster end cover 307 by bolts to position the bearing.

[0066] The driving piston 302 is a hollow two-stage stepped shaft, which is sleeved on the transmission shaft 301, and the outer circle of the small diameter end is provided with a sealing groove 302a, and a sealing ring is installed in the sealing groove 302a, and cooperates with the inner hole at the corresponding position of the connecting seat 9 sleeved on the driving piston 302 to form a first seal, and the outer circle 302b of the large diameter end cooperates with the sealing ring installed in the sealing ring installation groove at the corresponding position on the connecting seat 9 to form a second seal; the first seal and the second seal form a sealing chamber Y between the driving piston 302 and the connecting seat 9, and an oil inlet connected to the sealing chamber Y is provided on the connecting seat 9. Hydraulic oil enters the sealing chamber Y through the oil inlet on the connecting seat 9, pushing the driving piston 302 to move from the small diameter end to the large diameter end, and the small diameter end of the driving piston 302 is the end close to the driving shaft 201;

[0067] Preferably, the driving piston 302 is provided with a two-step inner hole, and the side facing the angle adjuster end cover 307 is a large-diameter inner hole, and the transmission shaft 301 is provided with a corresponding shoulder matching the two-step inner holes, thereby limiting the displacement distance of the driving piston 302 in the axial direction to prevent the driving piston 302 from moving beyond the limit.

[0068] The transmission piston 304 is a disc-shaped part with a central through hole. It is sleeved on the transmission shaft 301, and the left end is in contact with the large diameter end of the driving piston 302, and the right end is in contact with the moving gear disc 306. Its main function is to transmit the driving force of the driving piston 302 (the driving force for displacement to the right end) to the moving gear disc 306, so that the moving gear disc 306 moves toward the angle adjuster end cover 307.

[0069] The main body of the movable toothed disc 306 is a disc-shaped part with a central through hole, and a stepped through hole in the middle for passing the transmission shaft 301 and the fixed shaft 305b of the fixed toothed disc 305, and the through hole facing the angle adjuster end cover is a large-diameter through hole, the inner end surface of the large-diameter through hole is used to withstand the end thrust of the spring 309, and the end surface of the movable toothed disc 306 facing the transmission piston 304 is provided with first bevel teeth 306b distributed along the circumference, and the outer circumferential surface is provided with evenly distributed bosses 306a, which cooperate with the grooves 310c in the inner hole of the rotary seat 310 sleeved thereon, so as to transmit the rotation and torque of the rotary reducer 303 connected to the rotary seat 310;

[0070] The fixed gear disc 305 comprises a gear disc 305a and a fixed shaft 305b located at the center of the gear disc 305a. The fixed shaft 305b is a hollow shaft with a keyway provided in the internal through hole, which allows the fixed gear disc 305 to form a key connection with the transmission shaft 301, thereby fixing the connection in the circumferential direction to limit the rotation between the fixed gear disc 305 and the transmission shaft 301. The fixed shaft 305b is inserted into the central through hole of the movable gear disc. The end surface of the gear disc 305a facing the movable gear disc 306 is provided with a second helical tooth distributed along the circumference and meshing with the first helical tooth 306b of the movable gear disc 306. Specifically, the fixed gear disc 305 is fixed to the transmission shaft 301 by a flat key 311, preventing the fixed gear disc 305 and the transmission shaft 301 from rotating relative to each other. The two ends of the fixed gear disc 305 are further axially stopped by means of a shaft shoulder of the transmission shaft 301 and a distance sleeve 406.

[0071] The main body of the angle adjuster end cover 307 is a three-step stepped hollow disc structure, which is mounted on the transmission shaft 301 through a bearing sleeve, and the maximum outer diameter section 307a is respectively provided with a flange connected to the rotary seat 310 mounted on the mobile gear disc 306, and a flange connected to the bearing cover 308, the middle diameter section 307b is used to cooperate with the rotary seat 310 for installation and to limit the axial movement distance of the mobile gear disc 306, and the minimum diameter section 307c is used to cooperate with the mobile gear disc 306 for installation, that is, the large diameter through hole in the mobile gear disc 306 and the minimum diameter section 307c are connected. The outer circles match and form an axial sliding connection, and the end face of the minimum diameter section is provided with a plurality of mounting holes 307d evenly distributed along the circumference for mounting a spring 309, wherein the minimum diameter section 307c is the end of the angle adjuster end cover 307 close to the drive shaft 201, and the bearing pressure cover 308 is fixed to the outside of the angle adjuster end cover 307 by bolts to limit the axial position of the bearing; the spring 309 is installed between the angle adjuster end cover 307 and the movable gear disc 306 through the mounting hole 307d to provide a thrust to the movable gear disc 306 toward the fixed gear disc 305.

[0072] The main body of the swivel seat 310 is cylindrical and is sleeved on the outside of the movable gear disc 306. The left end of the swivel seat 310 is a swivel reducer connecting disc 310a, which is used to connect the output disc of the swivel reducer 303 with a self-locking function. The right end is an end cover connecting disc 310b, which is used to install the angle adjuster end cover 307, and the middle diameter section 307b in the angle adjuster end cover 307 is matched with the inner cavity of the swivel seat 310 to leave space for installing the movable gear disc 306; the interior of the swivel seat 310 is a through hole, and is provided with a groove 310c corresponding to the boss 306a of the movable gear disc 306. A circumferential fixed connection is formed between the swivel seat 310 and the movable gear disc 306 through the boss 306a and the groove 310c, and the movable gear disc 306 can be axially displaced relative to the swivel seat 310.

[0073] The connecting seat 9 is used to connect the angle adjuster 3 with the transmission 2. The transmission 2 is mounted on the drive shaft 201 and is mainly used to transmit the torque and rotation of the drive shaft 201 to the main shaft 10. The connecting seat 9 is a hollow cylinder, and its outer circle is divided into three diameter levels, among which the diameter of the middle section is the largest to form a middle bulge. The end faces on both sides of the middle section are respectively attached to and fixedly connected with the transmission 2 and the rotary reducer 303 to achieve relative axial positioning between the three elements, wherein the left section (close to the end of the drive shaft 201) is inserted into the cavity of the transmission 2 and connected to the bearing mounted on the drive shaft 201, and serves as an axial stop for the bearing mounted on the drive shaft 201, and a sealing groove is provided on it, and the cavity of the transmission 2 is sealed by installing a sealing ring; the right section extends toward the inside of the rotary reducer 303 to facilitate the installation guide of the rotary reducer 303.

[0074] The inner diameter of the connecting seat 9 is also divided into three levels of aperture, among which the inner diameter of the left inner section matches the transmission shaft 301 and is provided with a sealing groove, and the transmission 2 is sealed for the second time by installing a sealing ring; the middle inner section and the right inner section respectively match the outer diameter of the two-stage stepped shaft of the driving piston 302, and a sealing ring installation groove is provided on the right inner section, and a sealing ring is installed, that is, the middle inner section and the right inner section respectively match the outer circle 302b of the small diameter end and the large diameter end of the driving piston 302, forming the first seal and the second seal respectively, thereby forming a sealed cavity Y, wherein the sealing groove 302a corresponding to the middle inner section and the sealing ring installed is provided on the driving piston 302 On, a first seal is formed, a sealing groove is provided on the right inner section and a sealing ring is installed to match the outer circle 302b of the large diameter end to form a second seal, and a sealing chamber Y is formed between the connecting seat 9 and the driving piston 302 through the first seal and the second seal, and an oil inlet is provided on the outer surface of the connecting seat 9 at a position corresponding to the sealing chamber Y. The hydraulic oil enters the sealing chamber Y through the oil inlet on the connecting seat 9, pushing the driving piston 302 to move from the right end, and then pushing the transmission piston 304 and the moving gear disc 306, and further compressing the spring 309 through the moving gear disc 306, thereby releasing the helical tooth engagement between the moving gear disc 306 and the fixed gear disc 305.

[0075] The rotary reducer 303 is mounted on the right section of the connecting seat 9 and is fixedly connected to the middle section of the connecting seat 9. The output disk (such as a gear disk or worm gear) of the rotary reducer 303 is fixedly connected to the rotating seat 310 by bolts, thereby limiting the relative rotation of the output disk of the rotary reducer 303 and the rotating seat 310. The rotary reducer 303 has two main functions. First, it drives the drive shaft 201 to rotate relatively slowly (compared to the drive of the main motor 1) through the transmission shaft 301, and transmits this rotation through the transmission 2, thereby accurately controlling the output rotation angle. Second, because the rotary reducer 303 has a self-locking function and the self-locking torque of the rotary reducer 303 is greater than the output torque of the main motor 1, it can prevent the main motor 1 from driving the drive shaft 201 to rotate under the locked working condition, thereby achieving the locking and anti-rotation of the entire transmission 2.

[0076] Preferably, the rotary reducer 303 is a worm gear rotary reducer with a self-locking function, that is, the rotary reducer connecting plate 310a is connected to the worm wheel, which serves as the output plate of the worm gear rotary reducer, and the worm wheel is mounted on the drive shaft 301 via the connecting seat 9 and the drive piston 302 to ensure synchronous rotation of the worm wheel and the rotary seat 310. Existing worm gear rotary reducers have a transmission ratio of 1:100 or higher. However, in the prior art, the minimum speed of the main shaft driven by the main motor 1 (the main shaft is driven by the transmission 14) reaches approximately 50 rpm (300° / s). Therefore, the angle adjuster 3, through the worm gear rotary reducer, can control the spindle output speed to within 1 / 100 of the prior art (≤3° / s), which is very conducive to accurate adjustment and timely stopping, significantly improving the accuracy and efficiency of tool face angle adjustment.

[0077] Specifically, the worm gear rotary reducer includes a drive source, a worm, a worm wheel, and a slewing bearing. The slewing bearing is sleeved on the connecting seat and fixedly connected. The worm wheel is rotatably connected to the outer circle of the slewing bearing via a roller and is connected in conjunction with the worm, thereby achieving the purpose of coaxiality between the output disk (i.e., the worm wheel) of the rotary reducer and the slewing seat. The drive source is connected to one end of the worm to drive the worm to rotate. Since the worm gear transmission has the characteristic of reverse self-locking, reverse self-locking can be achieved, that is, only the worm can drive the worm wheel, and the worm wheel cannot drive the worm to move, thereby providing it with a self-locking function. The drive source is an electric motor or a hydraulic motor. In this embodiment, a hydraulic motor is preferably used to adapt to complex underground coal mine operations.

[0078] In another embodiment, the rotary reducer 303 is any one of the rotary reducers such as RV reducer, harmonic reducer, etc., and the structure serving as the output disk (or called rotary disk) in the aforementioned rotary reducer 303 is also fixedly connected to the rotary seat 10.

[0079] The above-mentioned angle adjuster 3 has two working conditions, and its working principle is as follows:

[0080] Locking working condition: no pressure oil enters the sealed chamber Y formed by the driving piston 302 and the connecting seat 9 from the oil inlet of the connecting seat 9, the driving piston 302 is not driven by the external pressure oil, and the spring 309 always applies an axial force to the movable gear disc 306 toward the fixed gear disc 305, keeping the helical teeth of the movable gear disc 306 meshing with the helical teeth of the fixed gear disc 305; at this time, the main motor 1 and the driving shaft 201 are connected to the rotary reducer 303 through the transmission shaft 301, the fixed gear disc 305, the movable gear disc 306, and the rotary seat 310, and the rotary reducer 303 is in its working state. It has a self-locking function within the force range (that is, the self-locking torque of the slewing reducer 303 is greater than the output torque of the main motor 1), thereby forming a locking effect on the transmission system of the transmission 2, and the main motor 1 cannot transmit motion through the transmission 2; however, if the slewing reducer 303 is driven at this time, the slewing reducer 303 can drive the drive shaft 201 to rotate at a relatively slow speed (compared with the main motor drive), and transmit the rotation and torque through the transmission 2, thereby accurately controlling the rotation angle of the main shaft 10 and the active drill rod 6, thereby accurately and efficiently adjusting the tool face angle.

[0081] Unlocking condition: Pressurized oil is injected into the sealed chamber Y between the drive piston 302 and the connecting seat 9 through the oil inlet of the connecting seat 9. The hydraulic pressure drives the drive piston 302, pushing the transmission piston 304 and the movable gear plate 306 in the direction of disengaging from the fixed gear plate 305. At this time, the spring 309 is squeezed by the movable gear plate 306 and contracts, disengaging the helical teeth of the movable gear plate 306 from the fixed gear plate 305. The self-locking effect of the rotary reducer 303 cannot be transmitted to the transmission shaft 301, the drive shaft 201, and the main motor 1. Therefore, the main motor 1 can drive the drive shaft 201 to rotate, thereby outputting rotation and torque through the transmission 2.

[0082] The water braid 4 is a water inlet device for drilling drive water. The driving water enters the main shaft 10 of the power head through the water braid 4, and then reaches the drill bit position through several connected drill rods. The main feature of the water braid 4 is axial force balance. It includes a core shaft 402, a water inlet assembly 403, a bearing seat 404, a sealing shaft 409 and a core shaft support bearing 401. The water inlet assembly 403 is sleeved on the core shaft 402 and rotatably connected. The bearing seat 404 is sleeved on the core shaft 402 and rotatably connected through the core shaft support bearings 401 built into both ends of the bearing seat 404. The sealing shaft 409 is threadedly connected to the right end of the core shaft 402 to seal the right end of the core shaft 402.

[0083] The core shaft 402 is a hollow shaft, and its left end is fixedly connected to the connecting shaft 7 by a thread, wherein the thread on the core shaft 402 is an external thread, and the thread on the connecting shaft 7 is an internal thread. A water inlet hole is provided in the middle of the core shaft 402, and the water inlet hole is connected to the water inlet assembly 403. The inside of the right end is provided with a mounting thread for mounting the sealing shaft 409;

[0084] The water inlet assembly 403 includes a water inlet and a shell connected to the water inlet. The water inlet is used to connect to the water pipe joint. The shell is sleeved on the core shaft and rotatably connected. The inner cavity of the shell is connected to the water inlet hole of the core shaft 402, and the shell cooperates with the bearing seat 404, that is, one side of the shell is connected to one side of the bearing seat 404 to form a core shaft mounting structure. At the same time, the inner cavity of the shell is a symmetrical structure, and the symmetrical plane is perpendicular to the axis of the core shaft 402 to balance its axial force, thereby achieving axial force balance of the water braid 4. Because the inner cavity of the shell in the water inlet assembly 403 is completely symmetrical about the middle plane, the force exerted by the driving water on the water inlet assembly 403 is balanced in the direction of the core shaft axis, thereby improving the force condition of the core shaft support bearing 401 and extending its service life.

[0085] Preferably, a sealing ring is provided between the housing and the core shaft 402 to form a sealing structure.

[0086] Specifically, a cover plate 408 is screwed onto the right end of the core shaft 402 to axially secure the sealing shaft 409. A water braid end cap 407 is screwed onto the right end of the bearing seat 404 to axially secure the core shaft support bearing 401. A grease nipple 405 is provided on the bearing seat 404, connecting to the inner cavity of the bearing seat 404. A sealing ring is also provided at the connection between the sealing shaft 409 and the core shaft 402 to prevent water leakage.

[0087] The connecting shaft 7 is a hollow shaft and is internally arranged in the main shaft 10. Its two ends are respectively connected to the core shaft 402 of the water braid 4 and the active drill rod 6, so as to transmit the axial impact received by the water braid 4 to the active drill rod 6 with an axial floating structure, thereby improving the stress condition of the water braid 4. An external thread 701 is provided at the left end of the connecting shaft 7 for connecting to the threaded hole at the right end of the active drill rod 6, and an internal thread 703 is provided at the right end of the connecting shaft 7 for connecting to the external thread of the water braid core shaft 402; a hexagonal head 702 is provided on the outer side of the right end of the connecting shaft 7, and the connecting sleeve 8 is fixedly connected to the end of the main shaft 10 of the power head close to the water braid 4 through a threaded connection, and the inner hole of the connecting sleeve 8 is a hexagonal hole matching the hexagonal head 702, and the hexagonal head 702 at the right end of the connecting shaft 7 is inserted into the hexagonal hole of the connecting sleeve 8, so that a moving pair is formed between the connecting sleeve 8 and the connecting shaft 7, and the rotation of the connecting shaft 7 is restricted. The moving pair formed between the connecting sleeve 8 and the connecting shaft 7 cooperates with the axial floating structure for limiting displacement of the active drill rod 6, so that the core shaft 402, the connecting shaft 7, and the active drill rod 6 as a whole also have an axial floating structure for limiting displacement, thereby making the connecting shaft 7 and the core shaft 402 in the water braid 1 also have an axial floating function.

[0088] Among them, the axial floating structure of the active drill rod 6 includes a spring and a drill rod end cover. The active drill rod 6 can be connected to the chuck 5 by transmitting torque through a spline, a flat key, etc., and a spring mounting hole is provided on the right end face of the active drill rod 6. A spring is installed between the active drill rod 6 and the chuck 5 through the spring mounting hole, so that the active drill rod 6 has an axial floating function for buffering axial impact, and then the drill rod end cover fixedly connected to the chuck 5 is used for axial limitation, so that the active drill rod 6 has an axial floating function for limiting displacement.

[0089] Specifically, assuming that the maximum distance between the right end face of the active drill rod 6 and the left end face of the chuck 5 corresponding thereto is a, and the pitch of the thread of the active drill rod 6 and the drill rod joint connected thereto is p, then a≤p. This is because the axial impact of the threaded joint must occur within the displacement of one pitch (of course, it is very likely that the impact will occur at each pitch). If one thread (one pitch) cannot be connected, the subsequent threads will certainly not be able to connect. However, the floating distance should not be too small. If it is too small, the floating buffering effect will not be achieved due to insufficient floating distance. Therefore, based on the basic symmetry of the two sides of the thread, the minimum value of a is selected to be slightly larger than 0.5p. Preferably, a∈[0.65p,0.95p], and 0.65p is most preferred.

[0090] The hexagonal head 702 and intermediate cylindrical section of the connecting shaft 7 naturally form multiple, evenly distributed axial stop faces. These stop faces, in conjunction with the left end face of the connecting sleeve 8, limit rightward axial displacement of the connecting shaft 3. Assuming the distance b between the stop face and the left end face of the connecting sleeve 8 when the active drill rod 6 and the connecting shaft 7 are at the forwardmost position under floating conditions, then b should be greater than a. This distance ensures that the active drill rod's floating function is fully utilized, preventing axial rightward impacts from being directly transmitted from the connecting shaft 7 to the core shaft support bearing. In addition, the distance b is appropriately larger (i.e. not too larger) than the distance a between the active drill rod and the end face of the chuck, preferably b≥a+0.35p, so that even when a is selected to the minimum preferred value of 0.65p, a buffer distance of more than one pitch can be ensured, so that the axial buffer structure has a better buffering protection effect, and can limit the rightward displacement of the connecting shaft 3 in extreme cases where the floating function of the active drill rod fails or the active drill rod and the chuck end face are crushed, thereby avoiding serious damage to the chuck 6 or other parts of the power head.

[0091] The main shaft 10 is housed within the transmission 2 and rotates under the drive of the transmission 2. The end of the main shaft 10, away from the water braid 4, is connected to the chuck 5, driving the rotation of the chuck 5. The chuck 5 then transmits torque to the active drill rod 6. Specifically, the active drill rod 6, the connecting shaft 7, the connecting sleeve 8, and the core shaft 1402, sealing shaft 409, and cover plate 408 in the water braid 4 all rotate relative to the water inlet assembly 403, the bearing seat 404, the water braid end cover 407, and the transmission 2 housing.

[0092] Through the above connection relationship, the water braid 4 can achieve axial force balance during the drilling process, thereby solving the problem that the core shaft support bearing 401 is easily damaged. Its working principle is as follows:

[0093] Drilling drive water is fed from the water inlet assembly 403 into the core shaft 402, then passes through the core shaft 402, the connecting shaft 7, and the active drill rod 6 directly to the bottom hole motor and drill bit. Firstly, because the inner cavity of the housing of the water inlet assembly 403 is completely symmetrical about the midplane, the force exerted by the drive water on the water inlet assembly 403 is balanced along the axis of the core shaft 402, greatly improving the stress on the core shaft support bearing 401 and thereby extending its service life.

[0094] Secondly, the core shaft 402 of the water braid 4 is connected to the active drill rod 6 through the connecting shaft 7. The cooperation between the hexagonal head and the hexagonal hole of the connecting shaft 7 and the connecting sleeve 8 forms a stable moving pair, which prevents relative rotation. Combined with the axial floating function of limiting displacement of the active drill rod 6, it can not only float back and forth to buffer the axial impact received by the power head during drilling, but also limit the axial floating distance of the active drill rod 6, the connecting shaft 7 and the core shaft 402, thereby protecting other related parts, so that the connecting shaft 7 and the core shaft 402 have axial floating displacement. Therefore, the water braid 4 (core shaft 402) moves axially with the active drill rod 6 and the connecting shaft 7 during the rotation process of the active drill rod 6 and the drilling process of the power head. The axial impact received is transmitted to the active drill rod 6, and the active drill rod 6 is damped and absorbed by the spring installed between the active drill rod 6 and the main shaft 10, thereby further improving the stress condition of the core shaft support bearing 401.

[0095] The axial displacement restriction of the active drill rod 6 by the drill rod end cover can be adaptively adjusted according to the actual needs of other related components to adapt to different coal mine drilling rigs.

[0096] To sum up, the solution of the symmetrical shell cavity of the water inlet assembly in the water braid 4 combined with the connecting shaft 7 to transmit the impact to the active drill rod 6 with floating function improves the stress condition of the core shaft support bearing 401. The axial force generated by the pressure of the drilling drive water in the water braid 4 is evenly distributed, and the working impact of the power head is borne by the active drill rod 6 with floating function. Therefore, the drilling drive water pressure balancing mechanism solves the problems of unbalanced liquid pressure inside the water braid of the existing drilling rig, lack of force transmission mechanism, and easy damage of the core shaft support bearing 401. It is particularly suitable for situations where the drilling drive water pressure is high, such as when mud pulses are used in directional drilling.

[0097] The chuck 5 is the drill rod clamping mechanism of the directional drilling rig's power head. Generally, the chuck 5 in this embodiment does not hold the drill rod during drilling, so a normally open chuck is preferred. This allows for the removal of the active drill rod 6 at the front of the chuck 5 when a larger diameter drill rod needs to be temporarily replaced or salvaged during downhole drilling. Specifically, a piston-type hydraulic chuck, such as that disclosed in Chinese Patent Publication No. CN105822238B, is preferably used.

[0098] The active drill rod 6 is a drill rod connection mechanism during normal drilling. The front end of the active drill rod 6 is provided with a threaded joint similar to the drill rod male joint, which is used to connect with the drill rod added to the drilling rig during drilling. It is connected to the front end of the chuck 5 through the drill rod end cover and bolts to limit the axial displacement of the active drill rod, and a spring is provided between the active drill rod 5 and the chuck 6 to enable the active drill rod 5 to have an axial floating function.

[0099] In another embodiment, the active drill rod 6 is directly connected to the main shaft 10. Its specific structure is a floating drill rod connection device disclosed in Chinese patent publication number CN112253017B, which also has axial floating kinetic energy to meet the requirement that one end of the connecting shaft 7 is connected to an active drill rod with an axial floating structure. The focus is on transferring the active drill rod 6 from being connected to the chuck 5 to being connected to the main shaft 10. The remaining details are disclosed in the above patent and will not be repeated here.

[0100] The above-mentioned directional drilling rig power head with rotation angle control and braking function can provide various operating conditions for the directional drilling rig, including sliding directional drilling, tool face angle adjustment, rotary drilling, composite drilling and drill pipe fishing. Its working principle is as follows:

[0101] (1) Sliding directional drilling

[0102] During sliding directional drilling, the angle adjuster 3 is locked, preventing the main shaft 10 from rotating under the drive of the main motor 1. The power head is connected to multiple drill rods via the active drill rod 6, with the front end of the drill rod being equipped with a downhole motor. The drilling drive medium (pressure fluid) enters the power head through the water braid 4, passes through the connecting shaft, the active drill rod, and the drill rod, and enters the downhole motor, driving the downhole motor to rotate, implementing sliding directional drilling.

[0103] (2) Tool face angle adjustment

[0104] Under the tool face angle adjustment condition, the angle adjuster 3 is in a locked condition, and the main shaft 10 cannot rotate under the drive of the main motor 1, but can only rotate under the drive of the rotary reducer 303. At this time, oil is not supplied to the main motor 1, but oil is supplied to the hydraulic motor in the rotary reducer 303.

[0105] The rotary reducer 303 drives the transmission shaft 301, which in turn drives the main shaft 10 and the active drill rod 6 via the drive shaft 201 in the transmission 2. The active drill rod 6 then drives the connected drill rods, thereby adjusting the tool face angle. Because the rotary reducer 303 has a large transmission ratio, combined with the transmission ratio of the transmission 2, efficient and accurate tool face angle adjustment can be achieved by controlling the rotational speed of the rotary reducer 303.

[0106] (3) Rotary drilling

[0107] Under rotary drilling conditions, the angle adjuster 3 is in the unlocked condition, and the main shaft 10 can rotate under the drive of the main motor 1. Supplying oil to the main motor 1 can drive the main shaft 10 and the drill pipe to rotate, and implement rotary drilling. At this time, the driving medium is not provided to the bottom hole motor through the water braid 4.

[0108] (4) Composite drilling

[0109] During hybrid drilling, angle adjuster 3 is unlocked, allowing spindle 10 to rotate under the drive of main motor 1. This allows the water braid 4 to provide drive medium to the bottom-hole motor, which in turn drives the motor, while the main motor 1 also drives the drill rod, achieving hybrid drilling.

[0110] (5) Salvage drill pipe

[0111] When a drill is lost, a salvage drill rod is needed to remove the drill rod from the hole. Generally, the diameter of the salvage drill rod is larger than the diameter of the construction drill rod, so a chuck 5 is needed to clamp the salvage drill rod for construction. In the salvage drill rod working condition, the active drill rod 6, the connecting shaft 7, and the water braid 4 must be removed first, the salvage drill rod must be installed into the power head, and the salvage drill rod must be clamped by the chuck 5, and then several salvage drill rods must be connected in sequence until they contact the lost drill rod in the hole. In this working condition, the angle adjuster 3 is in the unlocked working condition, and the main shaft 10 can rotate under the drive of the main motor 1.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A power head of a directional drilling rig, comprising a main motor, a transmission and a main shaft. The transmission has a drive shaft. One end of the drive shaft is connected to the main motor, and the drive shaft is in meshing transmission with the main shaft through gears in the transmission. It is characterized in that: The other end of the drive shaft is connected with an angle adjuster through a transmission. The angle adjuster includes a drive shaft, a fixed gear disk, a movable gear disk, a rotary seat and a rotary speed reducer with a self-locking function. One end of the drive shaft is circumferentially and fixedly connected with the drive shaft. The fixed gear disk and the movable gear disk are both sleeved on the drive shaft, and the fixed gear disk and the movable gear disk are in helical engagement. The fixed gear disk is circumferentially and fixedly connected with the drive shaft. The movable gear disk is rotatably connected with the drive shaft, and the movable gear disk can slide along the axial direction of the drive shaft. The rotary seat is sleeved on the movable gear disk and circumferentially and fixedly connected. The output disk of the rotary speed reducer is coaxially and fixedly connected with the rotary seat to transmit the rotation of the output disk of the rotary speed reducer to the movable gear disk.

2. The power head of the directional drilling rig according to claim 1, characterized in that: The angle adjuster further includes a drive piston and a connecting seat. The drive piston is sleeved on the drive shaft and is located on the side of the fixed gear disk away from the movable gear disk. One end of the drive piston away from the drive shaft is connected with the movable gear disk. The connecting seat is sleeved on the drive piston. The outer diameter of the connecting seat is divided into three levels of diameters, and the diameter of the middle section is the largest. The two end faces of the middle section are respectively connected with the transmission and the rotary speed reducer to realize the relative axial positioning among the transmission, the connecting seat and the rotary speed reducer. The inner diameter of the connecting seat is divided into three levels of apertures. The two apertures away from the transmission match the outer diameter of the drive piston and are sleeved on the drive piston. The drive piston is a two-stage stepped shaft. A sealing groove is provided on the outer circle of the small-diameter end. A sealing ring is installed in the sealing groove and cooperates with the corresponding position of the connecting seat sleeved on it to form a first seal. The outer circle of the large-diameter end cooperates with the sealing ring installed at the corresponding position of the connecting seat to form a second seal. A sealing cavity is formed between the first seal and the second seal and is located between the drive piston and the connecting seat. An oil inlet communicating with the sealing cavity is provided on the connecting seat. The drive piston pushes the movable gear disk in the direction away from the fixed gear disk under the action of the hydraulic oil entering the sealing cavity through the oil inlet, so that the movable gear disk can slide along the axial direction of the drive shaft.

3. The power head of the directional drilling rig according to claim 2, characterized in that: The angle adjuster further includes an angle adjuster end cover. The other end of the drive shaft is rotatably connected in the angle adjuster end cover. The movable gear disk is a disk-shaped part with a central through hole, and the central through hole is a stepped through hole. The through hole on the side facing the angle adjuster end cover is a large-diameter through hole. The movable gear disk is sleeved on the angle adjuster end cover through the large-diameter through hole and is slidably connected. The end face of the movable gear disk facing the drive piston is provided with first helical teeth distributed along the circumference, and the fixed gear disk is provided with second helical teeth meshing with the first helical teeth. A spring is arranged between the inner end face of the large-diameter through hole and the end face of the angle adjuster end cover opposite to the inner end face, so that the first helical teeth and the second helical teeth are meshed under the thrust of the spring. The outer circumferential surface of the movable gear disk is provided with evenly distributed bosses. The rotary seat is sleeved on the movable gear disk and is provided with grooves matching the bosses to be circumferentially fixedly connected to the movable gear disk. One end of the rotary seat is provided with a rotary reducer connection disk fixedly connecting the output disk of the rotary reducer to transmit the rotation of the output disk in the rotary reducer to the movable gear disk.

4. The power head of the directional drilling rig according to claim 3, wherein: A transmission piston is further provided between the driving piston and the movable gear disk. The transmission piston is sleeved on the transmission shaft and is slidably connected. One end of the transmission piston is connected to the driving piston, and the other end is connected to the movable gear disk to transmit the thrust of the driving piston.

5. The power head of the directional drilling rig with a rotation angle control and braking function according to claim 3, wherein: The rotary seat is cylindrical. One end thereof away from the rotary reducer connection disk is provided with an end cover connection disk to be fixedly connected to the angle adjuster end cover.

6. The power head of the directional drilling rig according to claim 3, wherein: The fixed gear disk has a gear disk and a fixed shaft located at the center of the gear disk. The second helical gear is arranged on the gear disk. The fixed shaft is inserted into the central through hole of the movable gear disk, and a key groove is arranged in the fixed shaft so that the fixed gear disk is circumferentially fixedly connected to the transmission shaft through key connection.

7. The power head of the directional drilling rig according to claim 3, characterized in that: The angle adjuster end cover is a three-stage stepped hollow disk-shaped structure. It is sleeved on the transmission shaft through a bearing. The largest outer diameter section is provided with a flange connected to the rotary seat, and the largest outer diameter section is located at one end away from the driving shaft. The middle diameter section is used to carry the rotary seat and limit the axial movement distance of the movable gear disk. The smallest diameter section is axially slidably connected to the large-diameter through hole of the movable gear disk, and the end face of the smallest diameter section is provided with a plurality of spring mounting holes evenly distributed along the circumference for installing springs.

8. The directional drilling rig power head according to claim 3, wherein: The driving shaft is arranged inside the transmission. One side end face of the middle section in the connecting seat is in contact with the transmission. A section of the connecting seat close to the transmission is inserted into the transmission and serves as an axial stop for the bearing sleeved on the driving shaft. A section close to the rotary reducer extends into the rotary reducer for guiding the installation of the rotary reducer.

9. A power head of a directional drilling rig, comprising a main motor, a transmission, a main shaft, a driving drill pipe and a water swivel. The main motor is connected to the main shaft through the transmission. One end of the main shaft is fixedly connected to the driving drill pipe in a circumferential direction. It is characterized in that: It further includes a connecting shaft and a connecting sleeve. The water braid includes a core shaft, a water inlet assembly, a bearing seat, a sealing shaft, and a core shaft support bearing. The water inlet assembly is sleeved on the core shaft and is rotatably connected. The bearing seat is sleeved on the core shaft through the core shaft support bearings arranged at both ends of the bearing seat and is rotatably connected. The core shaft is a hollow shaft. Its left end is fixedly connected to the connecting shaft. The inner side of its right end is connected to the sealing shaft to seal the right end of the core shaft. The core shaft is provided with a water inlet hole, and the water inlet hole communicates with the water inlet assembly. The water inlet assembly includes a water inlet and a housing communicating with the water inlet. The inner cavity of the housing is a symmetric structure, and the symmetry plane is perpendicular to the axis of the core shaft to make its axial force balanced. The water inlet assembly is sleeved on the core shaft through the housing, and the inner cavity of the housing communicates with the water inlet hole of the core shaft. The connecting shaft is a hollow shaft and is internally disposed in the main shaft. Its two ends are respectively connected to the mandrel and the active drill pipe with an axial floating structure. A hexagon head is provided at one end of the connecting shaft close to the mandrel. The connecting sleeve is fixedly connected to one end of the main shaft close to the water braid and is sleeved on the connecting shaft. A hexagonal hole matching the hexagon head is provided inside it to form a sliding connection restricting rotation between the connecting shaft and the connecting sleeve, so that the connecting shaft and the mandrel have axial floating.

10. The directional drilling rig power head according to claim 9, characterized in that: It further includes a chuck. The chuck is connected to the end of the main shaft away from the water braid and rotates with the main shaft. The axial floating structure of the active drill pipe includes a spring and a drill pipe end cover. A key connection is provided between the active drill pipe and the chuck to make the main shaft and the active drill pipe fixedly connected in the circumferential direction. And the spring is arranged on the end face of the active drill pipe close to the chuck so that the active drill pipe can float axially. The drill pipe end cover is sleeved on the active drill pipe and fixedly connected to the chuck to limit the axial floating distance of the active drill pipe.

11. The power head of the directional drilling rig according to claim 10, characterized in that: Let the maximum distance between the end face of the active drill pipe close to the chuck and the corresponding end face of the chuck be a, and the pitch of the thread of the active drill pipe and the drill pipe joint connected thereto be p. Then a ≤ p.

12. The directional drilling rig power head according to claim 10, characterized in that: The hexagon head and the middle cylindrical section of the connecting shaft form a plurality of axially stopping end faces evenly distributed. And the stopping end faces match the end faces of the connecting sleeve close to the connecting shaft. Let the distance between the stopping end face and the end face of the connecting sleeve close to the connecting shaft be b when the active drill pipe floats axially to the leftmost end. Then b > a.

13. The directional drilling rig power head according to claim 9, characterized in that: The mandrel and the connecting shaft are fixedly connected by threads. The thread of the mandrel is an external thread, and the thread of the connecting shaft is an internal thread.

14. The directional drilling rig power head according to claim 9, characterized in that: A cover plate is fixedly connected to the right end of the mandrel to axially fix the sealing shaft.

15. A power head of a directional drilling rig, comprising a main motor, a transmission, a main shaft, a driving drill pipe and a water swivel. The transmission has a driving shaft. One end of the driving shaft is connected to the main motor, and the driving shaft is meshed with the main shaft through gears in the transmission. One end of the main shaft is circumferentially and fixedly connected to the driving drill pipe. It is characterized in that: The other end of the drive shaft is connected to an angle adjuster through a transmission. The angle adjuster includes a drive shaft, a fixed gear disk, a moving gear disk, a rotary seat, and a rotary reducer with a self-locking function. One end of the drive shaft is fixedly connected to the drive shaft in the circumferential direction. The fixed gear disk and the moving gear disk are both sleeved on the drive shaft, and the fixed gear disk and the moving gear disk are meshed with helical teeth. The fixed gear disk is fixedly connected to the drive shaft in the circumferential direction. The moving gear disk is rotatably connected to the drive shaft, and the moving gear disk can slide axially along the drive shaft. The rotary seat is sleeved on the moving gear disk and fixedly connected in the circumferential direction. The output disk of the rotary reducer is coaxially and fixedly connected to the rotary seat to transmit the rotation of the output disk of the rotary reducer to the moving gear disk. This directional drilling rig power head further includes a connecting shaft and a connecting sleeve. The water braid includes a mandrel, a water inlet assembly, a bearing seat, a sealing shaft, and a mandrel support bearing. The water inlet assembly is sleeved on the mandrel and rotatably connected. The bearing seat is sleeved on the mandrel through mandrel support bearings provided at both ends of the bearing seat and rotatably connected. The mandrel is a hollow shaft, its left end is fixedly connected to the connecting shaft, the inner side of its right end is connected to a sealing shaft to seal the right end of the mandrel, and the mandrel is provided with a water inlet hole which communicates with the water inlet assembly. The water inlet assembly includes a water inlet and a housing communicating with the water inlet. The inner cavity of the housing is a symmetric structure, and the symmetry plane is perpendicular to the axis of the mandrel to balance the axial force thereon. The water inlet assembly is sleeved on the mandrel through the housing, and the inner cavity of the housing communicates with the water inlet hole of the mandrel; The connecting shaft is a hollow shaft and is arranged inside the main shaft. Its two ends are respectively connected to the mandrel and the active drill pipe with an axial floating structure. A hexagon head is provided at one end of the connecting shaft close to the mandrel. The connecting sleeve is fixedly connected to one end of the main shaft close to the water braid and is sleeved on the connecting shaft. A hexagon hole matching the hexagon head is arranged inside it to form a sliding connection restricting rotation between the connecting shaft and the connecting sleeve, so that the connecting shaft and the mandrel have axial floating.

16. The directional drilling rig power head according to claim 15, characterized in that: The angle adjuster further includes a driving piston and a connecting seat. The driving piston is sleeved on the transmission shaft and is located on the side of the fixed gear disk away from the moving gear disk close to it. One end of the driving piston away from the driving shaft is connected to the moving gear disk; The connecting seat is sleeved on the driving piston. The outer diameter of the connecting seat is divided into three levels of diameters, and the diameter of the middle section is the largest. The two end faces on both sides of the middle section are respectively connected to the transmission and the slewing reducer to realize the relative axial positioning between the transmission, the connecting seat and the slewing reducer. The inner diameter of the connecting seat is divided into three levels of apertures. The apertures of the two sections away from the transmission match the outer diameter of the driving piston and are sleeved on the driving piston; The driving piston is a two-stage stepped shaft. A sealing groove is provided on the outer circle of its small-diameter end. A sealing ring is installed in the sealing groove and cooperates with the corresponding position of the connecting seat sleeved on it to form a first seal. The outer circle of the large-diameter end cooperates with the sealing ring installed at the corresponding position of the connecting seat to form a second seal. A sealing cavity is formed between the first seal and the second seal and is located between the driving piston and the connecting seat. An oil inlet communicating with the sealing cavity is provided on the connecting seat. The driving piston pushes the moving gear disk in the direction away from the fixed gear disk under the action of the hydraulic oil entering the sealing cavity through the oil inlet, so that the moving gear disk can slide axially along the transmission shaft.

17. The power head of the directional drilling rig according to claim 15, characterized in that: The angle adjuster further includes an angle adjuster end cover. The other end of the transmission shaft is rotatably connected within the angle adjuster end cover. The moving gear disk is a disk-shaped part with a central through hole, and the central through hole is a stepped through hole. The large-diameter through hole of the stepped through hole faces the side of the angle adjuster end cover. The moving gear disk is sleeved on the angle adjuster end cover through the large-diameter through hole and is slidably connected. The end face of the moving gear disk facing the driving piston is provided with first helical teeth distributed along the circumference. The fixed gear disk is provided with second helical teeth meshing with the first helical teeth, and a spring is arranged between the inner end face of the large-diameter through hole and the end face of the angle adjuster end cover opposite to the inner end face, so that the first helical teeth and the second helical teeth are meshed under the thrust of the spring; The outer circumferential surface of the moving gear disk is provided with evenly distributed bosses. The rotary seat is sleeved on the moving gear disk and is provided with grooves matching the bosses to be circumferentially fixedly connected to the moving gear disk. One end of the rotary seat is provided with a rotary reducer connecting disk fixedly connecting the output disk of the rotary reducer to transmit the rotation of the output disk in the rotary reducer to the moving gear disk.

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