Rotation angle control and braking apparatus for power head of directional drilling rig

Abstract

A rotation angle control and braking apparatus for a power head of a directional drilling rig, relating to the technical field of coal mine drilling rigs. The apparatus comprises a propeller shaft (1), a driving piston (2), a fixed toothed disc (5), a movable toothed disc (6), an end cover (7), a rotary base (10), a connection base (12), and a rotary reducer (3) having a self-locking function. One end of the propeller shaft (1) is circumferentially fixedly connected to a drive shaft (13) in the power head of the directional drilling rig. The driving piston (2), the fixed toothed disc (5), and the movable toothed disc (6) are all sleeved on the propeller shaft (1), and the fixed toothed disc (5) and the propeller shaft (1) are circumferentially fixedly connected. A spring (9) is arranged between the movable toothed disc (6) and the end cover (7). Under the action of the spring (9), helical teeth of the movable toothed disc (6) and the fixed toothed disc (5) mesh with one another. A sealing cavity (Y) is arranged between the connection base (12) and the driving piston (2), and by means of injecting oil into the sealing cavity (Y), the driving piston (2) and the movable toothed disc (6) are driven to move towards the end cover (7), so as to disengage the meshing between the helical teeth. The rotary base (10) is circumferentially fixedly connected on the outer side of the movable toothed disc (6), and is fixedly connected to an output disc of the rotary reducer (3).

Description

Rotation angle control and braking device for directional drilling rig power head Technical Field

[0001] The invention belongs to the technical field of coal mine drilling rigs and relates to a rotation angle control and braking device for a power head of a directional drilling rig. 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] 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.

[0004] Summary of the Invention

[0005] In view of this, an object of the present invention is to provide a rotation angle control and braking device for a directional drilling rig power head, so as to solve the problem that the tool face angle cannot be accurately adjusted during the existing directional drilling process.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A rotation angle control and braking device for a directional drilling rig power head, the key of which is that it includes a transmission shaft, a driving piston, a fixed gear disc, a movable gear disc, an end cover, a slewing seat, a connecting seat and a slewing reducer with a self-locking function, one end of the transmission shaft is circumferentially fixedly connected to the driving shaft of the main motor in the directional drilling rig power head, and the other end is rotatably connected to the end cover, the driving piston, the fixed gear disc and the movable gear disc are all sleeved on the transmission shaft, and the driving piston is located at the end of the transmission shaft close to the driving shaft, and the end of the driving piston away from the driving shaft is connected to the movable gear disc, the fixed gear disc and the transmission shaft are circumferentially fixedly connected, and the fixed gear disc is located between the driving piston and the movable gear disc;

[0008] 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 end cover. The movable gear disc is sleeved on the 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 end cover corresponding to the inner end surface, so that the first helical teeth and the second helical teeth are meshed under the thrust of the spring;

[0009] 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 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;

[0010] The connecting seat is sleeved on the driving piston, the outer circle of the connecting seat is divided into three levels of diameter, and the diameter of the middle section is the largest, and the end faces on both sides of the middle section are respectively connected to the directional drilling rig power head and the rotary reducer to achieve relative axial positioning between the directional drilling rig power head, 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 directional drilling rig power head match the outer diameter of the driving piston and are sleeved on the driving piston, and the output disk of the rotary reducer is coaxial with the rotary seat;

[0011] 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, so that the driving piston pushes the movable gear disc toward the end cover under the action of hydraulic oil.

[0012] 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.

[0013] Furthermore, the slewing seat is cylindrical, and an end cover connecting plate is provided at one end thereof away from the slewing reducer connecting plate, so as to be fixedly connected to the end cover.

[0014] 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.

[0015] Furthermore, the rotary reducer is a worm gear rotary reducer with a self-locking function.

[0016] Furthermore, the transmission shaft and the drive shaft are spline-connected.

[0017] Furthermore, the end cover is a three-step stepped hollow disc structure, which is mounted on the transmission shaft through a bearing sleeve. The maximum outer diameter section is provided with a flange connected to the movable 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 mounting springs.

[0018] Furthermore, the drive shaft is installed in the transmission in the directional drilling rig power head, 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 for guiding the installation of the rotary reducer.

[0019] Furthermore, the small-diameter end of the driving piston is the end close to the driving shaft.

[0020] The beneficial effects of the present invention are:

[0021] The present invention provides a rotation angle control and braking device for the power head of a directional drilling rig, which has the functions of accurately adjusting the tool face angle and locking the drive shaft to prevent rotation. It not only realizes accurate and efficient adjustment of the tool face angle, but also prevents the rebound rotation of the power head main shaft caused by the elastic deformation of the drill pipe. It solves the problem that the drilling rig in the prior art lacks a special tool face angle adjustment device, has low trajectory adjustment accuracy and efficiency, and is difficult to achieve automatic directional drilling; at the same time, it greatly reduces the driving force required for tool face angle adjustment, has a good energy-saving effect, simplifies the structure of the rotation braking device of the main motor, and converts the functions of a large number of internal parts into an external rotary reducer, thereby eliminating the need for a large number of friction plates, greatly reducing the difficulty of maintenance, and reducing the consumption of wearing parts.

[0022] Secondly, the present invention preferably adopts a worm gear rotary reducer with a self-locking function, and the transmission ratio of the existing worm gear rotary reducer can reach more than 1:100. However, the minimum speed of the main shaft driven by the main motor in the existing technology has also reached 50r / min (300° / s). The rotation angle control and braking device can control the main shaft output speed to within 1 / 100 of the existing technology (≤3° / s) through the worm gear rotary reducer, which will be very beneficial for accurate adjustment and timely stopping, and greatly improve the tool face angle adjustment accuracy and adjustment efficiency.

[0023] 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

[0024] 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:

[0025] FIG1 is a schematic structural diagram of a rotation angle control and braking device for a directional drilling rig power head according to the present invention;

[0026] FIG2 is a schematic structural diagram of the driving piston in the present invention;

[0027] FIG3 is a schematic structural diagram of a movable toothed disc in the present invention;

[0028] FIG4 is a schematic structural diagram of a fixed toothed disc in the present invention;

[0029] Figure 5 is a schematic structural diagram of the end cover of the present invention;

[0030] FIG6 is a schematic structural diagram of a rotary seat in the present invention;

[0031] FIG7 is a schematic structural diagram of a connecting base in the present invention;

[0032] FIG8 is a partial enlarged view of FIG1 .

[0033] Figure 1: Transmission shaft, 2: Driving piston, 201: Sealing groove, 202: Outer circle of large diameter end, 3: Rotary reducer, 4: Transmission piston, 5: Fixed gear plate, 501: Gear plate, 502: Fixed shaft, 6: Moving gear plate, 601: Boss, 602: First helical tooth, 7: End cover, 701: Maximum outer diameter section, 702: Middle diameter section, 703: Minimum diameter section, 704: Spring mounting hole , 8-bearing cover, 9-spring, 10-slewing seat, 1001-slewing reducer connecting plate, 1002-end cover connecting plate, 1003-groove, 11-flat key, 12-connecting seat, 1201-left section, 1202-middle section, 1203-right section, 1204-left inner section, 1205-middle inner section, 1206-right inner section, 13-drive shaft, 14-transmission, 15-main motor. DETAILED DESCRIPTION

[0034] 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.

[0035] 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.

[0036] 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.

[0037] Please refer to Figures 1 to 8, which are a rotation angle control and braking device for a directional drilling rig power head, including a transmission shaft 1, a slewing seat 10, a connecting seat 12, a bearing cover 8, a spring 9, a driving piston 2, a transmission piston 4, a fixed gear plate 5, a movable gear plate 6 and an end cover 7, which are sequentially sleeved on the transmission shaft 1 from left to right, and a slewing reducer 3 with a self-locking function, and the transmission ratio of the slewing reducer 3 is greater than the transmission ratio of the transmission 14 in the directional drilling rig power head; the left end of the transmission shaft 1 is splined and inserted into the drive shaft 13 of the main motor 15 in the directional drilling rig power head, and the drive shaft 13 is provided with a gear that is connected to the gear The splines on the transmission shaft 1 match the keyways, so that the transmission shaft 1 forms a spline connection with the drive shaft 13, thereby forming a circumferential fixed connection; the right end of the transmission shaft 1 is connected to the fixed gear disc 5 sleeved on the transmission shaft 1 through a flat key 11 to form a circumferential fixed connection, and is rotatably connected in the end cover 7 through a bearing, and the end cover 7 is located on the side of the fixed gear disc 5 away from the drive shaft 13, and is located on the right side of the fixed gear disc 5; a distance sleeve is provided on both sides of the bearing, and a bearing pressure cover 8 fixedly connected by bolts is provided on the side of the end cover 7 away from the fixed gear disc 5 to position the bearing.

[0038] The driving piston 2 is a hollow two-stage stepped shaft, which is sleeved on the transmission shaft 1, and the outer circle of the small-diameter end is provided with a sealing groove 201, in which a sealing ring is installed, which cooperates with the inner hole at the corresponding position of the connecting seat 12 sleeved thereon to form a first seal, and the outer circle 202 of the large-diameter end cooperates with the sealing ring installed in the sealing ring mounting 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 2 and the connecting seat 12, and an oil inlet connected to the sealing chamber Y is provided on the connecting seat 12. Hydraulic oil enters the sealing chamber Y through the oil inlet on the connecting seat 12, pushing the driving piston 2 to move from the small-diameter end to the large-diameter end, and the small-diameter end of the driving piston 2 is the end close to the driving shaft 13;

[0039] Preferably, the driving piston 2 has a two-step inner hole, and the side facing the end cover 7 is a large-diameter inner hole. The transmission shaft 1 is correspondingly provided with a shoulder matching the two-step inner holes, thereby limiting the displacement distance of the driving piston 2 in the axial direction.

[0040] The transmission piston 4 is a disc-shaped part with a central through hole. It is sleeved on the transmission shaft 1, and its left end is in contact with the large-diameter end of the driving piston 4, and its right end is in contact with the movable toothed disc 6. Its main function is to transmit the driving force of the driving piston 2 (the driving force for displacement to the right end) to the movable toothed disc 6, causing it to move to the right end as shown in Figure 1;

[0041] The main body of the movable toothed disc 6 is a disc-shaped part with a central through hole, with a stepped through hole in the middle for passing the transmission shaft 1 and the fixed shaft 502 of the fixed toothed disc 5, and the through hole facing the 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 9, the end surface of the movable toothed disc 6 facing the transmission piston 4 is provided with first bevel teeth 602 distributed along the circumference, and the outer circumferential surface is provided with evenly distributed bosses 601, which cooperate with the grooves 1003 of the inner hole of the rotary seat 10 to transmit the rotation of the rotary reducer 3 connected to the rotary seat 10;

[0042] The fixed gear disc 5 has a gear disc 501 and a fixed shaft 502 located at the center of the gear disc 501. The fixed shaft 502 is a hollow shaft with a keyway provided in the internal through hole, which allows the fixed gear disc 5 to form a key connection with the transmission shaft 1, thereby being fixedly connected in the circumferential direction to limit the rotation between the fixed gear disc 5 and the transmission shaft 1. The end surface of the gear disc 501 facing the movable gear disc 6 is provided with second helical teeth distributed along the circumference and meshing with the first helical teeth 602 of the movable gear disc 6. Specifically, the fixed gear disc 5 is fixed to the transmission shaft 1 by a flat key 11 to prevent relative rotation between the fixed gear disc 5 and the transmission shaft 1. The two ends of the fixed gear disc 5 are then axially stopped by means of the shaft shoulder and distance sleeve of the transmission shaft 1;

[0043] The main body of the end cover 7 is a three-step stepped hollow disc structure, which is mounted on the transmission shaft 1 through a bearing sleeve, and the maximum outer diameter section 701 is respectively provided with a flange connected to the rotary seat 10 sleeved on the movable gear disc 6, and a flange connected to the bearing pressure cover 8, the intermediate diameter section 702 is used to cooperate with the rotary seat 10 for installation and limit the axial movement distance of the movable gear disc 6, and the minimum diameter section 703 is used to cooperate with the movable gear disc 6 for installation, that is, the large diameter through hole in the movable gear disc 6 matches the outer circle of the minimum diameter section 703 and forms an axial sliding connection, and the end face of the minimum diameter section 703 is provided with a plurality of spring mounting holes 704 uniformly distributed along the circumference for installing the spring 9, wherein the minimum diameter section 703 is the end of the end cover 7 close to the drive shaft 13, and the bearing pressure cover 8 is fixed to the outside of the end cover 7 by bolts to axially limit the bearing; the spring 9 is installed between the end cover 7 and the movable gear disc 6 through the mounting hole 704 to provide the movable gear disc 6 with a thrust toward the fixed gear disc 5.

[0044] The main body of the swivel seat 10 is cylindrical and is sleeved on the outside of the movable gear disc 6. The left end of the swivel seat 10 is a swivel reducer connecting disc 1001, which is used to connect the output disc of the swivel reducer 3 with a self-locking function. The right end is an end cover connecting disc 1002, which is used to install the end cover 7 and cooperates with the middle diameter section 702 in the end cover 7 to leave space for installing the movable gear disc 6; the interior of the swivel seat 10 is a through hole, and is provided with a groove 1003 corresponding to the boss 601 of the movable gear disc 6. A circumferential fixed connection is formed between the swivel seat 10 and the movable gear disc 6 through the boss 601 and the groove 1003, and the movable gear disc 6 can be axially displaced relative to the swivel seat 10.

[0045] The connecting seat 12 is used to connect the rotation angle control and braking device with the transmission 14 in the directional drilling rig power head. The transmission 14 is sleeved on the drive shaft 13 and is mainly used to transmit the torque and rotation of the drive shaft 13 to the main shaft or drill pipe. The connecting seat 12 is a hollow cylinder, and its outer circle is divided into three levels of diameter. Among them, the diameter of the middle section 1202 is the largest to form a middle bulge. The end faces on both sides of the middle section 1202 are respectively attached to and fixedly connected with the transmission 14 and the rotary reducer 3 to achieve relative axial positioning between the three components. The left section 1201 (close to one end of the drive shaft 13) is inserted into the cavity of the transmission 14 and connected to the bearing sleeved on the drive shaft 13, and serves as an axial stop for the bearing sleeved on the drive shaft 13. A sealing groove is provided on it, and the cavity of the transmission 14 is sealed by installing a sealing ring; the right section 1203 extends into the interior of the rotary reducer 3 to facilitate the installation and guidance of the rotary reducer 3.

[0046] The inner diameter of the connecting seat 12 is also divided into three levels of aperture, among which the inner diameter of the left inner section 1204 matches the transmission shaft 1 and is provided with a sealing groove, and the transmission 14 is sealed for the second time by installing a sealing ring; the middle inner section 1205 and the right inner section 1206 respectively match the outer diameter of the two-stage stepped shaft of the driving piston 2, and a sealing ring installation groove is provided on the right inner section 1206, and a sealing ring is installed, that is, the middle inner section 1205 and the right inner section 1206 respectively match the outer circle of the small diameter end and the outer circle of the large diameter end 202 of the driving piston 2, forming a first seal and a second seal, respectively, thereby forming a sealed cavity Y, wherein the sealing ring corresponding to the middle inner section 1205 is installed. The sealing groove 201 of the sealing ring is provided on the driving piston 2 to form a first seal. A sealing groove is provided on the right inner section 1206 and a sealing ring is installed to match the large diameter outer circle 202 to form a second seal. A sealing chamber Y is formed between the connecting seat 12 and the driving piston 2 through the first seal and the second seal, and an oil inlet is provided on the outer surface of the connecting seat 12 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 12, pushing the driving piston 2 to move from the right end, and then pushing the transmission piston 4 and the moving gear disc 6, and further compressing the spring 9 through the moving gear disc 6, thereby releasing the helical tooth engagement between the moving gear disc 6 and the fixed gear disc 5.

[0047] The rotary reducer 3 is mounted on the right section 1203 of the connecting seat 12 and is fixedly connected to the middle section 1202 of the connecting seat 12. The output disk (such as a gear disk or worm gear) of the rotary reducer 3 is fixedly connected to the rotating seat 10 by bolts, thereby limiting the relative rotation between the output disk of the rotary reducer 3 and the rotating seat 10. The rotary reducer 3 has two main functions. First, it drives the drive shaft 13 to rotate relatively slowly (compared to the drive of the main motor 15) through the transmission shaft 1, and transmits this rotation through the transmission 14, thereby accurately controlling the output rotation angle. Second, because the rotary reducer 3 has a self-locking function and the self-locking torque of the rotary reducer 3 is greater than the output torque of the main motor 15, it can prevent the main motor 15 from driving the drive shaft 13 to rotate under the locking condition, thereby achieving the locking and anti-rotation of the entire transmission 14.

[0048] Preferably, the rotary reducer 3 is a worm gear rotary reducer with a self-locking function, that is, the rotary reducer connecting plate 1001 is connected to the worm wheel serving as the output plate in the worm gear rotary reducer, and the worm wheel is sleeved on the transmission shaft 1 via the connecting seat 12 and the driving piston 2 to ensure synchronous rotation of the worm wheel and the rotary seat 10. The transmission ratio of existing worm gear rotary reducers can reach 1:100 or above. However, the minimum speed of the spindle driven by the main motor 15 in the prior art (the spindle is driven by the transmission 14) is at least 50 r / min (300° / s). Therefore, the rotation angle control and braking device can control the spindle output speed to within 1 / 100 of the prior art (≤3° / s) through the worm gear rotary reducer, which is very conducive to accurate adjustment and timely stopping, greatly improving the tool face angle adjustment accuracy and adjustment efficiency.

[0049] 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 by bolts. The worm wheel is connected to the outer circle of the slewing bearing through a roller and is connected in conjunction with the worm, thereby achieving the purpose of the output disk of the rotary reducer (i.e., the worm wheel) being coaxial with 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 giving it 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.

[0050] In another embodiment, the rotary reducer 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 3 is also fixedly connected to the rotary seat 10.

[0051] The above-mentioned rotation angle control and braking device for the power head of a directional drilling rig has two working conditions, and its working principle is as follows:

[0052] Locking working condition: no pressure oil enters the sealed chamber Y formed by the driving piston 2 and the connecting seat 12 from the oil inlet of the connecting seat 12. The rotation angle control and braking device is not driven by the external pressure oil. The spring 9 always applies an axial force to the movable gear disc 6 toward the fixed gear disc 5 to keep the helical teeth of the movable gear disc 6 meshing with the helical teeth of the fixed gear disc 5. At this time, the main motor 15 and the driving shaft 13 are connected to the rotary reducer 3 through the transmission shaft 1, the fixed gear disc 5, the movable gear disc 6 and the rotary seat 10, and the rotary reducer 3 is within its working capacity. It has a self-locking function (i.e., the self-locking torque of the slewing reducer 3 is greater than the output torque of the main motor 15), thereby forming a locking effect on the transmission system of the transmission 14, and the main motor 15 cannot transmit motion through the transmission 14; however, if the slewing reducer 3 is driven at this time, the slewing reducer 3 can drive the drive shaft 13 to rotate at a relatively slow speed (compared with the main motor drive), and transmit the rotation and torque through the transmission 14, thereby accurately controlling the rotation angle of the main shaft and the drill rod, thereby accurately and efficiently adjusting the tool face angle.

[0053] Unlocking condition: Pressurized oil is injected into the sealed chamber Y between the drive piston 2 and the connecting seat 12 through the oil inlet of the connecting seat 12. The hydraulic pressure drives the drive piston 2, pushing the transmission piston 4 and the movable gear plate 6 in the direction of disengaging from the fixed gear plate 5. At this time, the spring 9 is squeezed by the movable gear plate 6 and contracts, disengaging the helical teeth of the movable gear plate 6 and the fixed gear plate 5. The self-locking effect of the rotary reducer 3 cannot be transmitted to the transmission shaft 1, the drive shaft 13, and the main motor 15. Therefore, the main motor 15 can drive the drive shaft 13 to rotate, thereby outputting rotation and torque through the transmission 14.

[0054] 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 rotation angle control and braking device for a directional drilling rig power head, characterized in that: It includes a transmission shaft, a driving piston, a fixed toothed disc, a movable toothed disc, an end cover, a slewing seat, a connecting seat and a slewing reducer with a self-locking function. One end of the transmission shaft is circumferentially fixedly connected to the driving shaft of the main motor in the directional drilling rig power head, and the other end is rotatably connected to the end cover. The driving piston, the fixed toothed disc and the movable toothed disc are all sleeved on the transmission shaft, and the driving piston is located at one end of the transmission shaft close to the driving shaft, and the end of the driving piston away from the driving shaft is connected to the movable toothed disc. The fixed toothed disc is circumferentially fixedly connected to the transmission shaft, and the fixed toothed disc is located between the driving piston and the movable toothed disc. The movable toothed 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 end cover. The movable toothed disc is sleeved on the end cover through the large-diameter through hole and slidably connected. The end surface of the movable toothed disc facing the driving piston is provided with first helical teeth distributed along the circumference, and the fixed toothed 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 end cover corresponding to the inner end surface, 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 toothed disc is provided with evenly distributed bosses, the rotary seat is sleeved on the movable toothed disc and is provided with grooves matching the bosses so as to be fixedly connected with the movable toothed disc in the circumferential direction, and one end of the rotary seat is provided with a rotary reducer connecting disc fixedly connected to the output disc of the rotary reducer so as to transmit the rotation of the output disc in the rotary reducer to the movable toothed disc; The connecting seat is sleeved on the driving piston, the outer circle of the connecting seat is divided into three levels of diameter, and the diameter of the middle section is the largest, and the end faces on both sides of the middle section are respectively connected to the directional drilling rig power head and the rotary reducer to achieve relative axial positioning between the directional drilling rig power head, the connecting seat and the rotary reducer, the inner diameter of the connecting seat is divided into three levels of aperture, wherein the two sections of aperture far away from the directional drilling rig power head match the outer diameter of the driving piston and are sleeved on the driving piston, and the output disk of the rotary reducer is coaxial with the rotary seat; The driving piston is a two-stage stepped shaft, and a sealing groove is provided on the outer circle of the small diameter end thereof. A sealing ring is installed in the sealing groove and cooperates with the corresponding position of the connecting seat sleeved 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 sealing cavity located between the driving piston and the connecting seat is formed between the first seal and the second seal, and an oil inlet connected to the sealing cavity is provided on the connecting seat, so that the driving piston pushes the movable gear disc toward the end cover under the action of hydraulic oil.

2. The rotation angle control and braking device for a directional drilling rig power head according to claim 1, characterized in that: A transmission piston is also provided between the driving piston and the movable toothed 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 toothed disc to transmit the thrust of the driving piston.

3. The rotation angle control and braking device for a directional drilling rig power head according to claim 1, characterized in that: The slewing seat is cylindrical, and an end cover connecting plate is provided at one end away from the slewing reducer connecting plate to be fixedly connected to the end cover.

4. The rotation angle control and braking device for a directional drilling rig power head according to claim 1, characterized in that: The fixed gear plate has a gear plate and a fixed shaft located at the center of the gear plate, the second bevel teeth are arranged on the gear plate, the fixed shaft is inserted into the central through hole of the movable gear plate, and a keyway is arranged in the fixed shaft, so that the fixed gear plate is circumferentially fixedly connected to the transmission shaft through a key connection.

5. The rotation angle control and braking device for a directional drilling rig power head according to claim 1, characterized in that: The rotary reducer is a worm gear rotary reducer with a self-locking function.

6. The rotation angle control and braking device for a directional drilling rig power head according to claim 1, characterized in that: The transmission shaft and the driving shaft are spline connected.

7. The rotation angle control and braking device for a directional drilling rig power head according to claim 1, characterized in that: The end cover is a three-stage stepped hollow disc structure, which is arranged on the transmission shaft through a bearing sleeve. The 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 plate. The minimum diameter section is axially slidingly connected to the large diameter through hole of the movable gear plate, and the end face of the minimum diameter section is provided with a plurality of spring mounting holes evenly distributed along the circumference for mounting springs.

8. The rotation angle control and braking device for a directional drilling rig power head according to claim 1, characterized in that: The drive shaft is arranged in the transmission in the directional drilling rig power head, 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 into the interior of the rotary reducer for guiding the installation of the rotary reducer.

9. The rotation angle control and braking device for a directional drilling rig power head according to claim 1, characterized in that: The small diameter end of the driving piston is the end close to the driving shaft.

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