Drilling machine power head speed change structure

Abstract

The invention discloses a drilling machine power head speed change structure which comprises a shell, a top plate is arranged at the top of the shell, a first speed change device is arranged on one side in the shell, a second speed change device is arranged on the other side in the shell, a speed change bin is arranged above the second speed change device, a stabilizing bin is arranged below the second speed change device, and a partition plate is arranged between the speed change bin and the stabilizing bin. A hydraulic motor is arranged in the center of the rotating sleeve, a sleeve gear is arranged on the outer side of the middle of the rotating sleeve in a surrounding mode, and hydraulic sleeves are arranged at the upper end and the lower end of the rotating sleeve. The two-stage speed change structure has the beneficial effects that torque can be superposed or reduced through relative rotation, the torque change range is enlarged, meanwhile, speed change is more uniform and reliable through cooperation of the stepless speed change type structure and the hydraulic motor, meanwhile, stability of the output torque of the motor is guaranteed, and the service life of the motor is prolonged. The drilling machine has the advantages of a motor drilling machine and a hydraulic drilling machine.

Description

Technical Field

[0001] The invention relates to the technical field related to a drilling rig power head, and in particular to a speed changing structure of a drilling rig power head. Background Art

[0002] A core drilling rig is a drilling equipment used for geological exploration, mainly used to obtain rock cores (i.e. rock samples) from underground for analysis and research. The core task of a core drilling rig is to obtain rock samples without destroying the original structure through drilling, so as to conduct scientific analysis of the properties, structure, and composition of underground rock formations. It is widely used in mineral exploration, oil and gas exploration, environmental investigation, hydrogeology and other fields. The core drilling rig power head (also called power unit) is the core component of the core drilling rig, responsible for providing rotational power and torque to drive the drill bit for drilling. The design and performance of the power head directly affect the drilling efficiency, stability and ability to adapt to different geological conditions of the drilling rig. According to their different driving modes and functions, core drilling rig power heads can be divided into different types.

[0003] Mechanical power heads are usually powered by internal combustion engines (such as diesel engines or gasoline engines). These internal combustion engines directly transmit power to the drill bit through mechanical transmission devices such as gears, chains or belts. The mechanical power provided by the internal combustion engine reduces the speed through a reduction device (such as a gear reducer) and drives the drill bit to rotate through a mechanical transmission system. The advantages of mechanical power heads are: the structure of mechanical power heads is relatively simple, and maintenance and repair are relatively easy; compared with hydraulic and electric systems, the initial investment of mechanical power systems is low, which is suitable for occasions with limited budgets; it is suitable for general drilling tasks, especially for harder rock formations or shallow drilling. Compared with hydraulic power systems, mechanical power heads have relatively low power output and may not provide sufficient power in deep wells or complex geological conditions. Internal combustion engines generate large noise when working, affecting the working environment; the power transmission efficiency of mechanical systems is not as high as that of hydraulic and electric systems, which may lead to reduced work efficiency.

[0004] The hydraulic power head is driven by a hydraulic system and is usually composed of a hydraulic pump, a hydraulic motor, an oil pipe and hydraulic oil. The hydraulic system converts the energy of high-pressure liquid into mechanical power to drive the drill bit to rotate. The hydraulic oil in the hydraulic system is pumped to the hydraulic motor, which rotates and generates torque to drive the drill bit for drilling. The hydraulic system can provide large torque and stable power output, so it is suitable for deeper and more complex geological environments, especially in hard rock formations and deep well drilling; the hydraulic power head can accurately adjust the speed and torque through the hydraulic control system to adapt to different drilling needs; the hydraulic system has less friction, works more smoothly, and reduces mechanical wear.

[0005] However, the hydraulic system structure is relatively complex, and the hydraulic oil, oil pipes and other parts need to be checked regularly, with high maintenance costs. The design and manufacturing costs of the hydraulic system are high, and usually require a high initial investment. The working performance of the hydraulic system is affected by temperature and hydraulic oil quality, and extreme environmental conditions may cause system performance to deteriorate.

[0006] The electric power head is driven by an electric motor, which converts high-speed rotation into low-speed, high-torque output through a reduction system to drive the drill bit to rotate. The motor is driven by electricity to generate rotational force, which is reduced by a reduction device and transmitted to the drill bit. The electric power head has low noise during operation and a relatively quiet working environment. In addition, the motor has high efficiency, low energy loss, and stable operation. The motor can achieve precise speed control with an electronic speed control system, which is particularly suitable for precision drilling tasks. The maintenance of the motor is relatively simple, and there is no oil replacement and sealing problem in the hydraulic system.

[0007] However, electric power heads rely on electricity supply and cannot operate in areas without power supply, which limits their scope of application. In addition, the output power of electric motors is usually lower than that of hydraulic systems. They are suitable for drilling in shallow or soft rock formations, but may not be strong enough for drilling in deep wells or hard rock formations. Electric motors are sensitive to voltage fluctuations and unstable power supply may cause unstable system operation.

[0008] Some high-performance core drills may use a hybrid system, such as combining an internal combustion engine with a hydraulic system or an electric motor to provide stronger power output and better flexibility.

[0009] This power system can choose to use an internal combustion engine, hydraulic system or electric motor to drive the drill bit as needed, and is typically used for drilling tasks that require high power output or diverse operating conditions.

[0010] The hybrid power head can switch the power source according to different operation requirements and adapt to various geological conditions.

[0011] The appropriate power form can be selected according to the actual situation, which can provide strong power and maintain good fuel economy. However, due to the need for the cooperation of multiple power sources, the design, manufacturing and maintenance costs are relatively high. The cooperation of multiple power sources increases the complexity of the system, and the maintenance and debugging work is relatively cumbersome. Summary of the invention

[0012] In view of the above shortcomings, the present invention aims to provide a speed change structure of a drilling rig power head. By simplifying the speed change structure and using a composite two-stage speed change control of a motor and a hydraulic motor, the motor and the hydraulic motor can simultaneously apply different steering directions and speeds to the drill bit, thereby ensuring output stability while improving speed adjustability. The technical solution of the present invention is as follows: A speed change structure of a drilling rig power head comprises a shell, a top plate is provided on the top of the shell, a first speed change device is provided on one side of the shell, a second speed change device is provided on the other side of the shell, a speed change chamber is provided above the second speed change device, a stabilizing chamber is provided below the second speed change device, a partition is provided between the speed change chamber and the stabilizing chamber, a rotating sleeve is provided at the center of the speed change chamber, a hydraulic motor is provided at the center of the rotating sleeve, a sleeve gear is arranged around the outer side of the middle of the rotating sleeve, rollers are symmetrically arranged on the rotating sleeves on the upper and lower sides of the sleeve gear, a sealing groove is provided on the outer side of the roller, hydraulic sleeves are provided at the upper and lower ends of the rotating sleeve, a fixing plate is provided at the bottom of the hydraulic sleeve, a sealing plate is arranged around the top of the hydraulic sleeve, the sealing groove corresponds to the sealing plate, the hydraulic sleeve forms a sealing chamber with the hydraulic motor through the fixing plate and the sealing plate, a plurality of oil holes corresponding to the sealing chamber are provided above and below the hydraulic motor, and an oil pipe is provided on one side of the hydraulic sleeve for connecting the inside of the hydraulic sleeve.

[0013] Furthermore, the first speed change device includes a gearbox, an input shaft, and an output shaft. The gearbox is in the shape of a strip with semicircular structures at both ends and a rectangular structure in the middle. The input shaft is provided at one end of the gearbox, and the output shaft is provided at the other end of the gearbox. The top end of the output shaft is provided with an output pulley, and the top end of the input shaft is provided with an input pulley. The input pulley and the output pulley are both provided with speed change disks at coaxial relative positions, and the speed change disks are connected by steel belts. A rotating shaft seat corresponding to the input shaft and the speed change disk is provided above the gearbox, and a rotating shaft seat corresponding to the output shaft and the speed change disk is also provided at the bottom of the shell. The speed change disk is arranged in the corresponding rotating shaft seat through a rotating shaft, and oil grooves are provided in the axes of the input shaft and the output shaft, and hydraulic compartments are provided in the input pulleys and the output pulleys. The oil grooves provided in the axes of the input shaft and the output shaft are correspondingly connected to the hydraulic compartments through through holes.

[0014] Furthermore, a sealing convex ring is arranged around the rotating sleeve in the middle of the upper and lower parts of the sealing plate, and sealing gaskets are arranged on the inner and outer rings of the sealing convex ring. The fixed plate is provided with a sealing ring, and the bottom of the hydraulic sleeve is provided with a sealing ring. The sealing ring, the fixed plate and the hydraulic sleeve are fixed to the partition plate and the top plate by screws.

[0015] Furthermore, the rotating shaft of the hydraulic motor passes through the fixing plate of the hydraulic sleeve below the gear shift chamber, and the fixing plate and the partition plate are provided with corresponding rotating shaft seats.

[0016] Furthermore, a power gear is provided at the rear end of the output shaft, the power gear is meshed with the sleeve gear, and the line connecting the axis of the input shaft and the rotating sleeve is arranged at an angle of 20 to 35 degrees with the gearbox.

[0017] Furthermore, two threaded ear seats are arranged outside the housing at the front and rear sides of the input shaft, the threaded ear seats are provided with internal threads, and sliders are arranged on both sides of the housing outside the input shaft, and the sliders are provided with sliding grooves.

[0018] Furthermore, a fixing block is provided in the stabilizing bin, the fixing block is provided with a circular groove, the shell at the bottom of the fixing block is provided with a small circular hole corresponding to the circular groove, a splint is provided in the circular hole, the splint includes a front splint and a rear splint, a threaded groove is provided on the fixing block on the rear side of the rear splint, connected to the circular groove on the inner wall, a threaded adjustment knob is provided in the threaded groove, a circular hole is provided on the fixing block on the front side of the front splint, a fixing seat is provided on the front side of the fixing block, a hydraulic telescopic rod is provided on the fixing seat, and the top of the hydraulic telescopic rod is arranged in the circular hole on the fixing block.

[0019] Furthermore, the oil pipe passes through the top plate and is connected to the hydraulic system, the input shaft is connected to the rotating shaft of the motor, the motor is arranged above the shell, and a pipeline structure corresponding to the oil tank is provided in the rotating shaft of the motor for connecting to the hydraulic system.

[0020] Furthermore, the motor, hydraulic motor, hydraulic telescopic rod and gearbox are all controlled by a computer control terminal.

[0021] Furthermore, the hydraulic motor is bidirectionally driven and is controlled by a bidirectional check valve to prevent reverse rotation.

[0022] The beneficial effects of the present invention are: 1. The continuously variable transmission device of the first transmission device makes the speed change of the drilling rig uniform, stable and accurate, and at the same time provides further torque through the rotation of the hydraulic motor, ensuring that the combined torque of the continuously variable transmission device and the hydraulic motor is controllable, ensuring the stability of the output torque, and further improving the drilling capacity; 2. The two-way drive of the hydraulic motor and the electric motor makes it possible to add or subtract the torque provided by the two, further expanding the adjustment range of the torque and ensuring sufficient torque output through the hydraulic motor; 3. Both the first transmission device and the second transmission device are gradual transmission devices, which ensure the smooth change of the rotation speed while maintaining the stability of the torque, reduce the influence of vibration on the drilling accuracy, and further stabilize the drill rod through the clamping structure to ensure Ensure high-precision drilling effect; 4. The speed change structure of the present invention is simple and the deceleration effect is good. The operation is controlled by the system to control the stepless speed change and the speed and direction of the hydraulic motor. The speed control is precise and accurate while the control is simple; 5. The present invention is suitable for deep drilling such as mining exploration, oil and gas exploration, especially in geological environments with complex geological layers and alternating soft and hard geological environments, and can be used for efficient and energy-saving drilling; in large-scale construction projects, bridge construction, and tunnel construction projects, it is particularly suitable for those occasions that require high-precision drilling, and is also suitable for operations that require fine control, such as environmental monitoring and soil sample collection. Due to the combination of motor drive and hydraulic system, this drilling rig is suitable for use in urban environments because of its low noise and low emissions, which meets urban environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A perspective view of the present invention; Figure 2 It is a schematic diagram of the internal structure of the present invention; Figure 3 It is a three-dimensional diagram of the internal device of the stabilizing chamber of the present invention; Figure 4 It is a schematic diagram of the internal structure of the stabilizing chamber of the present invention; Figure 5 is a perspective view of a second speed change device of the present invention; Figure 6 It is a schematic diagram of the internal structure of the second speed change device of the present invention; Figure 7 is a perspective view of the interior of a first transmission device of the present invention; Figure 8 It is a schematic diagram of the internal structure of the first speed change device of the present invention.

[0024] In the figure: 1-housing, 11-top plate, 12-threaded ear seat, 13-sliding block, 14-sliding groove, 2-first speed change device, 21-gearbox, 22-input shaft, 23-output shaft, 230-power gear, 24-input pulley, 25-output pulley, 26-speed change plate, 27-oil tank, 28-hydraulic chamber, 3-second speed change device, 30-partition plate, 31-speed change chamber, 32-stabilizing chamber, 321-fixing block, 322-circular groove, 323-small Circular hole, 324- splint, 3241- front splint, 3242- rear splint, 325- threaded adjustment knob, 326- fixed seat, 327- hydraulic telescopic rod, 33- rotating sleeve, 331- fixed plate, 332- sealing plate, 333- sealing convex ring, 334- sealing gasket, 34- hydraulic motor, 35- sleeve gear, 36- hydraulic sleeve, 37- sealing groove, 370- roller, 38- sealing chamber, 39- oil hole, 40- oil pipe. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Combination Figures 1 to 8 Shown: A speed change structure of a drilling rig power head includes a housing 1, a top plate 11 is provided on the top of the housing 1, a first speed change device 2 is provided on one side of the housing 1, the first speed change device 2 includes a gearbox 21, an input shaft 22, and an output shaft 23, the gearbox 21 is in the shape of a strip with semicircular structures at both ends and a rectangular structure in the middle, an input shaft 22 is provided at one end of the gearbox 21, an output shaft 23 is provided at the other end of the gearbox 21, an output pulley 25 is provided at the top of the output shaft 23, an input pulley 24 is provided at the top of the input shaft 22, and a speed change disc 26 is provided at a coaxial relative position of the input pulley 24 and the output pulley 25, and the speed change discs 26 are connected by a steel belt, and the speed change discs 26 are connected by a steel belt. A rotating shaft seat corresponding to the input shaft 22 and the speed change disc 26 is provided above the box 21, and a rotating shaft seat corresponding to the output shaft 23 and the speed change disc 26 is also provided at the bottom of the shell 1. The speed change disc 26 is set in the corresponding rotating shaft seat through the rotating shaft. The setting of the rotating shaft seat facilitates the rotation of the input shaft 22 and the output shaft 23. Oil grooves 27 are opened in the axes of the input shaft 22 and the output shaft 23, and hydraulic warehouses 28 are provided in the input pulley 24 and the output pulley 25. The oil grooves 27 set in the axes of the input shaft 22 and the output shaft 23 are correspondingly connected to the hydraulic warehouse 28 through through holes. The oil grooves 27 are connected to the hydraulic system, and the hydraulic system provides power to change the torque.

[0027] A second speed change device 3 is provided on the other side of the housing 1, a speed change chamber 31 is provided above the second speed change device 3, a stabilizing chamber 32 is provided below the second speed change device 3, and the output of the rotating shaft of the hydraulic motor is stabilized. A partition 30 is provided between the speed change chamber 31 and the stabilizing chamber 32, a rotating sleeve 33 is provided at the center of the speed change chamber 31, a hydraulic motor 34 is provided at the center of the rotating sleeve 33, a sleeve gear 35 is provided around the outer side of the middle of the rotating sleeve 33, rollers 370 are symmetrically provided on the rotating sleeve 33 on the upper and lower sides of the sleeve gear 35, and the rotating sleeve 33 can be rotated by the rollers 370, and the outer sealing grooves 37 of the rollers 370 rotate. Hydraulic sleeves 36 are provided at the upper and lower ends of the sleeve 33, and a fixing plate 331 is provided at the bottom of the hydraulic sleeve 36. A sealing plate 332 is provided around the top of the hydraulic sleeve 36, and a sealing convex ring 333 is provided around the rotating sleeve 33 in the upper and lower middle parts of the sealing plate 332. Sealing gaskets 334 are provided on the inner and outer rings of the sealing convex ring 333. A sealing ring is provided on the fixing plate 331, and a sealing ring is provided at the bottom of the hydraulic sleeve 36. The sealing ring, the fixing plate 331 and the hydraulic sleeve 36 are fixed to the partition plate 30 and the top plate 11 by screws to provide a corresponding sealing effect. A sealing structure can also be provided according to actual needs to further increase the sealing effect.

[0028] The sealing groove 37 corresponds to the sealing plate 332. The hydraulic sleeve 36 forms a sealing chamber 38 with the hydraulic motor 34 through the fixed plate 331 and the sealing plate 332. The hydraulic motor 34 is provided with a plurality of oil holes 39 corresponding to the sealing chamber 38 at the top and bottom. An oil pipe 40 is provided on one side of the hydraulic sleeve 36 to connect the inside of the hydraulic sleeve 36. The oil flows into the sealing chamber 38 through the oil pipe 40, and then flows into the hydraulic motor 34 through the oil hole 39. After driving the hydraulic motor 34, the oil flows out from the other corresponding oil holes 39 and the oil pipe 40. The corresponding oil holes 39 in different rotating sleeves 33 are used as oil inlets and outlets in the hydraulic motor 34 according to the direction of rotation.

[0029] The rotating shaft of the hydraulic motor 34 passes through the fixed plate 331 of the hydraulic sleeve 36 under the gear shift chamber 31, and the fixed plate 331 and the partition plate 30 are provided with corresponding rotating shaft seats to ensure the rotation ability of the hydraulic motor 34. At the same time, it can be set as a sealed shaft seat according to actual needs to prevent oil leakage.

[0030] A power gear 230 is provided at the rear end of the output shaft 23, and the power gear 230 meshes with the sleeve gear 35 for torque transmission. If necessary, a torque limiter can be provided to connect the power gear 230 and the output shaft 23 to prevent slipping caused by excessive torque. The axis connecting the power gear, the input shaft 22 and the rotating sleeve 33 is set at an angle of 20 to 35 degrees to the gearbox 21. The inclined setting optimizes and saves design space. Similarly, a corresponding braking device can be provided when necessary to fix the rotating sleeve 33.

[0031] Two threaded ear seats 12 are provided on the outside of the housing 1 on both sides of the input shaft 22. The threaded ear seats 12 are provided with internal threads. The threaded ear seats 12 can be raised and lowered by threaded rods to control the overall movement of the power head. Slide blocks 13 are provided on both sides of the housing 1 outside the input shaft 22. Slide blocks 14 are provided on the slide blocks 13. Slide rails corresponding to the slide blocks 14 are provided to cooperate with the lifting and lowering of the power head.

[0032] A fixed block 321 is provided in the stabilizing bin 32, and the fixed block 321 is provided with a circular groove 322. A small circular hole 323 corresponding to the circular groove 322 is provided on the shell 1 at the bottom of the fixed block 321, and a clamping plate 324 is provided in the circular groove 322. The clamping plate includes a front clamping plate 3241 and a rear clamping plate 3242. A threaded groove is opened on the fixed block 321 on the rear side of the rear clamping plate 3242 to connect to the inner wall circular groove 322, and a threaded adjustment knob 325 is provided in the threaded groove. The position of the rear clamping plate 3242 is controlled by the threaded adjustment knob 325. A circular hole is opened on the fixed block 321 on the front side of the front clamping plate 3241, and a fixed seat 326 is provided on the front side of the fixed block 321. A hydraulic telescopic rod 327 is provided on the fixed seat 326. The top of the hydraulic telescopic rod 327 is set in the circular hole on the fixed block 321, and the hydraulic telescopic rod is extended and retracted to control the clamping of the front clamping shoe.

[0033] The oil pipe 40 passes through the top plate 11 and is connected to the hydraulic system. The input shaft 22 is connected to the rotating shaft of the motor. The motor is arranged above the housing 1, and a pipeline structure corresponding to the oil tank 27 is provided in the rotating shaft of the motor for connecting the hydraulic system. The motor, the hydraulic motor 34, the hydraulic telescopic rod 327, and the gearbox 21 are all controlled by the computer control end.

[0034] The hydraulic motor 34 is a bidirectional drive structure, and the motor is unidirectionally driven. The unidirectional drive can prevent the relative force between the hydraulic motor and the rotating sleeve from causing the motor to reverse, affecting the torque output and increasing the output range. The motor is braked by a braking device such as an electromagnetic brake, and a servo motor can also be used when the torque requirement is not high.

[0035] Working principle: When drilling in shallow layers, the drilling rig can drill by running the motor alone, and add drill rods for replacement by reversing the hydraulic motor. The continuously variable speed change of the first speed change device ensures that there will be no vibration or other influences caused by speed change during drilling, which will affect the drilling accuracy. As the depth increases, the computer control end is set to control the operation of the motor and the hydraulic motor at the same time. The rotation of the hydraulic motor provides rotational force through the hydraulic system. The continuously variable speed change device provides rotational force for the rotating sleeve through the power gear and the sleeve gear. The same-direction torque can ensure the stability of the overall torque output during the continuously variable speed change. The reverse torque provided by the two improves the deceleration effect while ensuring the output Stability. When deceleration is required, the hydraulic motor can be used through reverse torque and continuously variable speed change alone or in combination to further improve the deceleration effect. When acceleration is required, the torque of the hydraulic motor can be further improved by controlling the hydraulic system, in the same direction as the torque transmitted by the motor, so that the drilling speed of the drill rod can be further improved. The combination of the motor and the hydraulic motor can achieve smooth output of high torque, so that the drilling capacity of the drilling rig can be further improved. At the same time, when the motor stops moving, the motor shaft can be locked by setting a braking device such as an electromagnetic brake to ensure that it does not rotate. The hydraulic device can be used alone to break through the difficult-to-drill rock formations through the large torque provided by the hydraulic device for further drilling.

[0036] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0037] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A speed change structure of a drilling rig power head, characterized in that: The invention comprises a housing (1), wherein a top plate (11) is provided on the top of the housing (1), a first speed change device (2) is provided on one side of the housing (1), a second speed change device (3) is provided on the other side of the housing (1), a speed change chamber (31) is provided above the second speed change device (3), a stabilizing chamber (32) is provided below the second speed change device (3), a partition plate (30) is provided between the speed change chamber (31) and the stabilizing chamber (32), a rotating sleeve (33) is provided at the center of the speed change chamber (31), a hydraulic motor (34) is provided at the center of the rotating sleeve (33), a sleeve gear (35) is provided around the outer side of the middle of the rotating sleeve (33), and rollers (370) are symmetrically provided on the rotating sleeve (33) at the upper and lower sides of the sleeve gear (35). ), a sealing groove (37) is provided on the outer side of the roller (370), a hydraulic sleeve (36) is provided at the upper and lower ends of the rotating sleeve (33), a fixing plate (331) is provided at the bottom of the hydraulic sleeve (36), a sealing plate (332) is provided at the top of the hydraulic sleeve (36) surrounding the hydraulic sleeve (36), the sealing groove (37) corresponds to the sealing plate (332), the hydraulic sleeve (36) forms a sealing chamber (38) with the hydraulic motor (34) through the fixing plate (331) and the sealing plate (332), the hydraulic motor (34) is provided with a plurality of oil holes (39) corresponding to the sealing chamber (38) at the upper and lower ends, and an oil pipe (40) is provided on one side of the hydraulic sleeve (36) for communicating with the interior of the hydraulic sleeve (36).

2. A speed change structure for a drilling rig power head according to claim 1, characterized in that: The first speed change device (2) comprises a gearbox (21), an input shaft (22), and an output shaft (23); the gearbox (21) is in the shape of a strip with semicircular structures at both ends and a rectangular structure in the middle; the input shaft (22) is provided at one end of the gearbox (21); the output shaft (23) is provided at the other end of the gearbox (21); an output pulley (25) is provided at the top end of the output shaft (23); an input pulley (24) is provided at the top end of the input shaft (22); the input pulley (24) and the output pulley (25) are both provided with speed change discs (26) at coaxial relative positions; the speed change discs (26) are connected by a steel belt. The gearbox (21) is provided with a rotating shaft seat corresponding to the input shaft (22) and the speed change plate (26) at the top, and the housing (1) is also provided with a rotating shaft seat corresponding to the output shaft (23) and the speed change plate (26) at the bottom. The speed change plate (26) is arranged in the corresponding rotating shaft seat via a rotating shaft. The input shaft (22) and the output shaft (23) are provided with oil grooves (27) in their axes. The input pulley (24) and the output pulley (25) are provided with hydraulic chambers (28). The oil grooves (27) provided in the axes of the input shaft (22) and the output shaft (23) are connected to the hydraulic chambers (28) via through holes.

3. A speed change structure for a drilling rig power head according to claim 2, characterized in that: A sealing convex ring (333) is provided at the middle of the upper and lower parts of the sealing plate (332) around the rotating sleeve (33), and sealing gaskets (334) are provided on the inner ring and the outer ring of the sealing convex ring (333). The fixing plate (331) is provided with a sealing ring, and the bottom of the hydraulic sleeve (36) is provided with a sealing ring. The sealing ring, the fixing plate (331) and the hydraulic sleeve (36) are fixed to the partition plate (30) and the top plate (11) by screws.

4. The speed change structure of a drilling rig power head according to claim 1, characterized in that: The rotating shaft of the hydraulic motor (34) passes through the fixing plate (331) of the hydraulic sleeve (36) below the gear shift chamber (31), and the fixing plate (331) and the partition plate (30) are provided with corresponding rotating shaft seats.

5. The speed change structure of a drilling rig power head according to claim 2, characterized in that: A power gear (230) is provided at the rear end of the output shaft (23), the power gear (230) meshing with the sleeve gear (35), and the axis connecting the input shaft (22) and the rotating sleeve (33) is arranged at an angle of 20 to 35 degrees with the gearbox (21).

6. The speed change structure of a drilling rig power head according to claim 5, characterized in that: Two threaded ear seats (12) are provided on the outside of the housing (1) at the front and rear sides of the input shaft (22), and internal threads are provided in the threaded ear seats (12). Slide blocks (13) are provided on both sides of the housing (1) outside the input shaft (22), and slide grooves (14) are provided on the slide blocks (13).

7. The speed change structure of a drilling rig power head according to claim 3, characterized in that: A fixing block (321) is provided in the stabilizing chamber (32), the fixing block (321) is provided with a circular groove (322), a small circular hole (323) corresponding to the circular groove (322) is provided on the shell (1) at the bottom of the fixing block (321), a clamping plate (324) is provided in the circular groove (322), the clamping plate (324) comprises a front clamping plate (3241) and a rear clamping plate (3242), the fixing block (321) having a circular groove (322) and a circular groove (322) on the rear side of the fixing block (321). The fixed block (321) is provided with a threaded groove connected to the circular groove (322) on the inner wall, a threaded adjustment knob (325) is provided in the threaded groove, a circular hole is provided on the fixed block (321) at the front side of the front clamping plate (3241), a fixing seat (326) is provided at the front side of the fixed block (321), a hydraulic telescopic rod (327) is provided on the fixing seat (326), and the top of the hydraulic telescopic rod (327) is arranged in the circular hole on the fixed block (321).

8. The speed change structure of a drilling rig power head according to claim 7, characterized in that: The oil pipe (40) passes through the top plate (11) and is connected to the hydraulic system. The input shaft (22) is connected to the rotating shaft of the motor. The motor is arranged above the housing (1), and a pipeline structure corresponding to the oil tank (27) is provided in the rotating shaft of the motor for connecting to the hydraulic system.

9. The speed change structure of a drilling rig power head according to claim 8, characterized in that: The motor, the hydraulic motor (34), the hydraulic telescopic rod (327), and the gearbox (21) are all controlled by a computer control terminal.

10. A speed change structure for a drilling rig power head according to claim 9, characterized in that: The hydraulic motor (34) is bidirectionally driven and is controlled by a bidirectional check valve to prevent reverse rotation.

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