Flow-adjustable low-speed short screw drill

Abstract

The invention discloses a flow-adjustable low-speed short screw drill, relates to the technical field of screw drills, and aims to solve the problem that threaded connection is more easily affected by looseness or fatigue due to the fact that threaded connection is realized through threads and pre-tightening force. In order to solve the problems that in the well drilling process, a screw drill needs to bear the action of alternating stress such as torque, stretching, compression, bending and impact, and therefore threaded connection can not meet the requirement for high strength, a discharging assembly is arranged on one side of a bypass valve assembly, a motor assembly is arranged on one side of the discharging assembly, and the motor assembly is arranged on the other side of the discharging assembly. A transmission shaft assembly is arranged on one side of the motor assembly, connecting locking mechanisms are arranged at the outer ends of the connecting positions of the bypass valve assembly and the discharging assembly, the discharging assembly and the motor assembly and the motor assembly and the transmission shaft assembly, and a rotor is arranged in the motor assembly. Rotor through grooves are formed in the anti-falling connecting rod, the anti-falling nut and the rotor.

Description

Technical Field

[0001] The invention relates to the technical field of screw drill tools, in particular to a low-speed short screw drill tool with adjustable flow rate. Background Art

[0002] The low-speed short screw drilling tool is a type of volumetric downhole power drilling tool that uses drilling fluid as power and converts liquid pressure energy into mechanical energy. When the mud pumped out by the mud pump flows through the bypass valve and enters the motor, a certain pressure difference will be formed at the inlet and outlet of the motor. This pressure difference drives the rotor to rotate around the axis of the stator. The rotation of the rotor is transmitted to the drill bit through the universal shaft and the transmission shaft, thereby realizing the drilling operation.

[0003] The Chinese patent announcement number is CN108457598B, which discloses a hole-reaming screw drill device, which changes the hole-reaming method of the non-excavation drilling hole to the hole-reaming method of the milling hole. The hole-reaming screw drill device includes: a screw drill, a hole-reaming support frame, a hole-reaming drill bit and a front stabilizer. The hole-reaming drill bit is threadedly connected to the front end of the screw drill, and the hole-reaming drill bit is used to expand the milling hole, thereby expanding the milling hole into a large milling hole; the front stabilizer is threadedly connected to the front end of the hole-reaming support frame, and the front stabilizer is used to extend into the milling hole to straighten the hole-reaming support frame, the hole-reaming drill bit and the screw drill tool; wherein the screw drill tool is used to provide the torque and speed required for the hole-reaming drill bit to break the rock, so that the hole-reaming drill bit can rotate; wherein the hole-reaming support frame can convert the speed provided by the screw drill tool into the revolution of the hole-reaming drill bit, thereby enabling the hole-reaming drill bit to revolve around the large milling hole as the axis. Thus, the hole enlarging screw drill device of the present invention has a simple and reasonable structure and can enable a small drilling rig to complete the task of enlarging a large hole.

[0004] The above-mentioned existing technical solutions have the following defects: threaded connection is achieved by threads and preload, which are more susceptible to loosening or fatigue. During the drilling process, the screw drill needs to withstand alternating stresses such as torque, tension, compression, bending and impact, so the threaded connection may not meet the high strength requirements. At the same time, during the drilling process, the threaded part of the screw drill will rub against the well wall or other drilling tools, resulting in thread wear. Therefore, we propose a low-speed short screw drill with adjustable flow rate to solve the above-mentioned problems. Summary of the invention

[0005] The purpose of the present invention is to provide a low-speed short screw drill with adjustable flow rate, so as to solve the problem that the threaded connection proposed in the above background technology is realized by threads and preload, which are more susceptible to loosening or fatigue. During the drilling process, the screw drill needs to withstand alternating stresses such as torque, tension, compression, bending and impact, so the threaded connection may not meet the high strength requirements. At the same time, during the drilling process, the threaded part of the screw drill will rub against the well wall or other drilling tools, thereby causing the problem of thread wear.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a low-speed short screw drill with adjustable flow, comprising a bypass valve assembly, a drain assembly is arranged on one side of the bypass valve assembly, a motor assembly is arranged on one side of the drain assembly, a transmission shaft assembly is arranged on one side of the motor assembly, the bypass valve assembly and the drain assembly, the drain assembly and the motor assembly, and the motor assembly and the transmission shaft assembly are connected by threads, a connection locking mechanism is arranged at the outer end of the connection position between the bypass valve assembly and the drain assembly, the drain assembly and the motor assembly, and the motor assembly and the transmission shaft assembly, an anti-drop joint is arranged at the outer end of the drain assembly, an anti-drop connecting rod is arranged inside the anti-drop connecting rod, one end of the anti-drop connecting rod is fixedly connected to an anti-drop nut, a rotor is arranged inside the motor assembly, and a rotor through groove is opened inside the anti-drop connecting rod, the anti-drop nut and the rotor.

[0007] Preferably, a valve sleeve and a valve core are installed inside the bypass valve assembly, the valve sleeve is slidably connected to the bypass valve assembly, a spring is arranged between the valve sleeve and the valve core, and a bypass groove is opened on one side between the valve sleeve and the valve core.

[0008] Preferably, a stator is provided at the outer end of the motor assembly, a sealed cabin is provided inside the stator, the rotor is meshedly connected to the sealed cabin, and the rotor is fixedly connected to an anti-drop connecting rod.

[0009] Preferably, a universal joint and a transmission shaft are arranged inside the transmission shaft assembly, the rotor is located on one side of the universal joint, the transmission shaft is connected to the transmission shaft on the other side of the universal joint, and both ends of the universal joint are respectively connected to the rotor and the transmission shaft.

[0010] Preferably, a first connecting sleeve is provided at one end of the connecting and locking mechanism, and a second connecting sleeve is provided at the other end of the connecting and locking mechanism, the first connecting sleeve is respectively fixedly connected to one end of the bypass valve assembly close to the drain assembly, one end of the drain assembly close to the motor assembly, and one end of the motor assembly close to the transmission shaft assembly, and the second connecting sleeve is respectively fixedly connected to one end of the drain assembly close to the bypass valve assembly, one end of the motor assembly close to the drain assembly, and one end of the transmission shaft assembly close to the motor assembly.

[0011] Preferably, a positioning block groove is formed at the upper ends of the first connecting sleeve and the second connecting sleeve, a positioning block is rotatably installed above the positioning block groove of the first connecting sleeve, the positioning block is adapted and engaged with the positioning block groove of the second connecting sleeve, and the positioning block is an L-shaped structure.

[0012] Preferably, a first positioning block groove is provided inside one end of the positioning block, a second positioning block groove is provided inside the second connecting sleeve, the first positioning block groove and the second positioning block groove correspond to each other, a locking block is slidably provided inside the second positioning block groove, the locking block is slidably connected to the first positioning block groove, a first compression spring groove is symmetrically provided above and below the second positioning block groove, a positioning block retaining ring is fixedly provided at the rear end of the locking block, and a first compression spring is provided between the positioning block retaining ring and the first compression spring groove.

[0013] Preferably, a driving block groove is opened above the rear side of the second positioning block groove, and a driving block is slidably arranged inside the driving block groove. The lower end of the driving block and one end of the locking block are inclined and have the same inclination angle. A limited rotation rod is arranged internally for rotation at the upper end of the driving block, and a limited rotation cap is fixedly installed above the limited rotation rod.

[0014] Preferably, two limit bars are slidably and symmetrically installed inside the limit rotating cap, the limit bar is an L-shaped structure, a telescopic rod is arranged between the two limit bars, a second compression spring is mounted on the outer side of the telescopic rod, the two ends of the second compression spring are respectively fitted with the two limit bars, and the upper end of the limit bar passes through and extends to the top of the limit rotating cap.

[0015] Preferably, a limiting strip groove is provided at the upper end of the driving block groove, and the limiting strip groove includes a guiding area, a vertical area and a limiting strip anti-slip groove, the guiding area is located above the vertical area, the limiting strip anti-slip groove is located below the vertical area, the diameter of the guiding area gradually decreases from top to bottom, the diameter of the vertical area is the same as that of the guiding area, and the diameter of the limiting strip anti-slip groove is larger than the diameter of the vertical area.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. When the present invention is connected through the connection locking mechanism, the two assemblies are connected through threads. When they are rotated to the locked position, the positioning block of the first connecting sleeve is lowered, and the positioning block is rotatably connected through the rotating shaft between the positioning block and the first connecting sleeve. The positioning block is meshed with the positioning block of the second connecting sleeve. At this time, the driving block is pressed, and the driving block drives the driving block to move downward inside the driving block groove through the limiting rotating rod. The limiting strip in the limiting rotating cap first enters the guide area, and the diameter of the guiding area gradually decreases, so that the limiting strip is squeezed and moves into the limiting rotating cap. At the same time, the telescopic rod and the second compression spring are compressed. When the positioning block enters the vertical area, it slides with the vertical area. When it enters the anti-slip groove of the limiting strip, the elastic force of the second compression spring is released. The limit bar is released, thereby pushing the limit bar into the anti-slip groove of the limit bar to prevent the limit bar from moving out, and the position of the limit rotation cap is locked. When the driving block moves down, the inclined surface of the lower end of the driving block slides with the inclined surface of the locking block, thereby pushing the locking block into the first positioning block groove, and the extension of the locking block locks the rotation angle of the positioning block, thereby preventing the positioning block from loosening, and fixing the rotor and the universal shaft and the universal shaft and the transmission shaft. The housings of the stator and the transmission shaft assembly are connected through a connecting locking mechanism, and then the housing of the bypass valve assembly and the housing of the release assembly are connected through a connecting locking mechanism, thereby realizing the splicing of low-speed short screw drilling tools, and solving the problem that the threaded connection is achieved by threads and preload, and they are more susceptible to loosening or fatigue. During the drilling process, the screw drilling tool needs to withstand the effects of alternating stresses such as torque, tension, compression, bending and impact, so the threaded connection may not meet the high strength requirements. At the same time, during the drilling process, the threaded part of the screw drilling tool will rub against the well wall or other drilling tools, thereby causing the problem of thread wear.

[0018] 2. The anti-drop connecting rod, anti-drop nut and rotor of the present invention are provided with rotor slots inside. In order to increase the horsepower of the drill bit and the return speed of the mud, the rotor is processed into a hollow rotor with rotor slots. The total flow of this motor should be equal to the sum of the flow through the sealed cabin and the flow through the rotor slot. Each specification of the motor has its recommended maximum and minimum flow values. If the flow is too large, the rotor will overspeed, and the stator and rotor will be damaged prematurely. If the flow is too small, the motor will stop rotating. Therefore, when selecting the size of the rotor slot, it should be ensured that the flow of the sealed cabin is always maintained at or higher than the minimum recommended flow value so that the motor can operate normally. When the mud density, the size of the rotor slot and the motor flow are quantitative, the flow through the rotor slot and the flow through the sealed cabin always change with the load. When the drill bit leaves the bottom of the well, the motor load is approximately zero. At this time, the flow through the rotor slot is the smallest, and the flow through the sealed cabin is the largest. As the drill bit drills, the motor pressure difference continues to increase, which increases the flow through the rotor slot, while the flow through the sealed cabin decreases. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 is a cross-sectional view of the motor assembly of the present invention;

[0021] Figure 3 It is a structural schematic diagram of the connection and locking mechanism in the present invention;

[0022] Figure 4 For the present invention Figure 3 A partial enlarged view of area A;

[0023] Figure 5 It is a three-dimensional diagram of the driving block slot in the present invention.

[0024] In the figure: 1, bypass valve assembly; 2, release assembly; 3, motor assembly; 4, transmission shaft assembly; 5, valve sleeve; 6, bypass groove; 7, valve core; 8, anti-drop connecting rod; 9, anti-drop joint; 10, anti-drop nut; 11, positioning block groove; 12, rotor; 13, stator; 14, universal shaft; 15, transmission shaft; 16, connection locking mechanism; 17, rotor through groove; 18, sealing cabin; 19, first connecting sleeve; 20, second connecting sleeve; 21, Positioning block; 22. Locking block; 23. Driving block; 24. First positioning block groove; 25. Second positioning block groove; 26. Positioning block retaining ring; 27. First compression spring groove; 28. First compression spring; 29. ​​Driving block groove; 30. Limiting rotation rod; 31. Limiting rotation cap; 32. Limiting bar; 33. Limiting bar groove; 34. Telescopic rod; 35. Second compression spring; 36. Guide area; 37. Vertical area; 38. Limiting bar anti-slip groove. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0026] See also Figure 1-5An embodiment of the present invention is as follows: a low-speed short screw drill with adjustable flow, comprising a bypass valve assembly 1, a drain assembly 2 is arranged on one side of the bypass valve assembly 1, a motor assembly 3 is arranged on one side of the drain assembly 2, a transmission shaft assembly 4 is arranged on one side of the motor assembly 3, the bypass valve assembly 1 and the drain assembly 2, the drain assembly 2 and the motor assembly 3, and the motor assembly 3 and the transmission shaft assembly 4 are connected by threads, and a connection locking mechanism 16 is arranged at the outer end of the connection position between the bypass valve assembly 1 and the drain assembly 2, the drain assembly 2 and the motor assembly 3, and the motor assembly 3 and the transmission shaft assembly 4, an anti-drop joint 9 is arranged at the outer end of the drain assembly 2, an anti-drop connecting rod 8 is arranged inside the anti-drop connecting rod 9, and an anti-drop nut 10 is fixedly connected to one end of the anti-drop connecting rod 8, a rotor 12 is arranged inside the motor assembly 3, and a rotor through groove 17 is opened inside the anti-drop connecting rod 8, the anti-drop nut 10 and the rotor 12.

[0027] When connected by the connecting locking mechanism 16, the two assemblies are connected by threads. When they are rotated to the locked position, the positioning block 21 of the first connecting sleeve 19 is lowered. The positioning block 21 is rotatably connected with the first connecting sleeve 19 through the rotating shaft between the positioning block 21 and the first connecting sleeve 19. The positioning block 21 is meshed with the positioning block 21 of the second connecting sleeve 20. At this time, the driving block 23 is pressed, and the driving block 23 drives the driving block 23 to move downward inside the driving block groove 29 through the limiting rotating rod 30. The limiting strip 32 in the limiting rotating cap 31 first enters the guide area 36, ​​and the diameter of the guide area 36 gradually decreases, so that the limiting strip 32 is squeezed and moves into the limiting rotating cap 31. At the same time, the telescopic rod 34 and the second compression spring 35 are compressed. When the positioning block 21 enters the vertical area 37, it slides with the vertical area 37. When it enters the limiting After the positioning bar anti-slip groove 38 is engaged, the elastic force of the second compression spring 35 is released, thereby pushing the limiting bar 32 into the limiting bar anti-slip groove 38 to prevent the limiting bar 32 from moving out, locking the position of the limiting rotating cap 31, and when the driving block 23 moves downward, the inclined surface at the lower end of the driving block 23 slides with the inclined surface of the locking block 22, thereby pushing the locking block 22 into the first positioning block groove 24, and the extension of the locking block 22 locks the rotation angle of the positioning block 21, thereby preventing the positioning block 21 from loosening, fixing the rotor 12 and the universal shaft 14 as well as the universal shaft 14 and the transmission shaft 15, connecting the stator 13 and the housing of the transmission shaft assembly 4 through the connecting locking mechanism 16, and then connecting the housing of the bypass valve assembly 1 and the housing of the release assembly 2 through the connecting locking mechanism 16, thereby realizing the splicing of the low-speed short screw drilling tool.

[0028] See also Figure 1-2A valve sleeve 5 and a valve core 7 are installed inside the bypass valve assembly 1, the valve sleeve 5 is slidably connected to the bypass valve assembly 1, a spring is arranged between the valve sleeve 5 and the valve core 7, a bypass groove 6 is opened on one side between the valve sleeve 5 and the valve core 7, a stator 13 is arranged at the outer end of the motor assembly 3, a sealing cabin 18 is opened inside the stator 13, the rotor 12 is meshed and connected with the sealing cabin 18, the rotor 12 is fixedly connected with the anti-drop connecting rod 8, a universal shaft 14 and a transmission shaft 15 are arranged inside the transmission shaft assembly 4, the rotor 12 is located on one side of the universal shaft 14, the transmission shaft 15 is connected to the transmission shaft 15 on the other side of the universal shaft 14, and the two ends of the universal shaft 14 are respectively connected to the rotor 12 and the transmission shaft 15.

[0029] See also Figure 3-5A first connecting sleeve 19 is provided at one end of the connecting locking mechanism 16, and a second connecting sleeve 20 is provided at the other end of the connecting locking mechanism 16. The first connecting sleeve 19 is respectively fixedly connected to one end of the bypass valve assembly 1 close to the discharge assembly 2, one end of the discharge assembly 2 close to the motor assembly 3, and one end of the motor assembly 3 close to the transmission shaft assembly 4. The second connecting sleeve 20 is respectively connected to one end of the discharge assembly 2 close to the bypass valve assembly 1, one end of the motor assembly 3 close to the discharge assembly 2, and one end of the transmission shaft assembly 4 close to the motor assembly 3. The upper ends of the first connecting sleeve 19 and the second connecting sleeve 20 are provided with a positioning block groove 11. The positioning block groove of the first connecting sleeve 19 A positioning block 21 is rotatably installed above the second connecting sleeve 20, and the positioning block 21 is adapted and engaged with the positioning block groove 11 of the second connecting sleeve 20. The positioning block 21 is an L-shaped structure. A first positioning block groove 24 is provided inside one end of the positioning block 21, and a second positioning block groove 25 is provided inside the second connecting sleeve 20. The first positioning block groove 24 corresponds to the second positioning block groove 25. A locking block 22 is slidably provided inside the second positioning block groove 25. The locking block 22 is slidably connected to the first positioning block groove 24. A first compression spring groove 27 is symmetrically provided above and below the second positioning block groove 25. A positioning block retaining ring 26 is fixedly provided at the rear end of the locking block 22. A first compression spring 28 is arranged between the block retaining ring 26 and the first compression spring groove 27, a driving block groove 29 is opened above the rear side of the second positioning block groove 25, a driving block 23 is slidably arranged inside the driving block groove 29, the lower end of the driving block 23 and one end of the locking block 22 are tilted and have the same tilt angle, a limited rotation rod 30 is arranged internally and rotatably at the upper end of the driving block 23, a limited rotation cap 31 is fixedly installed above the limited rotation rod 30, two limit strips 32 are slidably and symmetrically installed inside the limit rotation cap 31, the limit strip 32 is an L-shaped structure, a telescopic rod 34 is arranged between the two limit strips 32, and the outer sleeve of the telescopic rod 34 A second compression spring 35 is installed, and the two ends of the second compression spring 35 are respectively fitted with the two limit strips 32. The upper end of the limit strip 32 passes through and extends to the top of the limit rotating cap 31. A limit strip groove 33 is set at the upper end of the driving block groove 29. The limit strip groove 33 includes a guide area 36, ​​a vertical area 37 and a limit strip anti-slip groove 38. The guide area 36 is located above the vertical area 37, and the limit strip anti-slip groove 38 is located below the vertical area 37. The diameter of the guide area 36 gradually decreases from top to bottom, the diameter of the vertical area 37 is the same as that of the guide area 36, ​​and the diameter of the limit strip anti-slip groove 38 is larger than the diameter of the vertical area 37.

[0030] Working principle: when in use, the anti-drop connecting rod 8 is fixedly connected to the rotor 12, and the anti-drop joint 9 is threadedly connected to the stator 13. When it is rotated to the locked position, the positioning block 21 of the first connecting sleeve 19 is lowered, and the positioning block 21 is rotatably connected with the rotating shaft between the positioning block 21 and the first connecting sleeve 19, and the positioning block 21 is meshed with the positioning block 21 of the second connecting sleeve 20. At this time, the driving block 23 is pressed, and the driving block 23 drives the driving block 23 to move downward inside the driving block groove 29 through the limiting rotating rod 30. The limiting strip 32 in the limiting rotating cap 31 first enters the guide area 36, ​​and the diameter of the guide area 36 gradually decreases, so that the limiting strip 32 is squeezed and moves into the limiting rotating cap 31. At the same time, the telescopic rod 34 and the second compression spring 35 are compressed. When the positioning block 21 enters the vertical area 37, it slides with the vertical area 37. After entering the limiting strip anti-drop groove 38, the elastic force of the second compression spring 35 is released, thereby limiting The positioning bar 32 is pushed into the anti-slip groove 38 of the positioning bar to prevent the positioning bar 32 from moving out, and the position of the limiting rotation cap 31 is locked. When the driving block 23 moves downward, the inclined surface of the lower end of the driving block 23 slides with the inclined surface of the locking block 22, thereby pushing the locking block 22 into the first positioning block groove 24. The extension of the locking block 22 locks the rotation angle of the positioning block 21, thereby preventing the positioning block 21 from loosening, and fixing the rotor 12 and the universal shaft 14 and the universal shaft 14. and the transmission shaft 15, the stator 13 and the housing of the transmission shaft assembly 4 are connected through the connection locking mechanism 16, and then the housing of the bypass valve assembly 1 and the housing of the release assembly 2 are connected through the connection locking mechanism 16, so as to realize the splicing of the low-speed short screw drilling tool. The anti-drop connecting rod 8, the anti-drop nut 10 and the rotor 12 are provided with a rotor through groove 17. In order to increase the horsepower of the drill bit and the return speed of the mud, the rotor is processed into a hollow rotor 12 with a rotor through groove 17. The total flow of this motor should be equal to the sum of the flow through the sealed cabin 18 and the flow through the rotor through groove 17. Each specification of the motor has its recommended maximum and minimum flow values. If the flow is too large, the rotor will overspeed, and the stator 13 and the rotor 12 will be damaged prematurely. If the flow is too small, the motor will stop rotating. Therefore, when selecting the size of the rotor through groove 17, it should be ensured that the flow of the sealed cabin 18 is always maintained at or above the minimum recommended flow value so that the motor can operate normally. When the mud density, the size of the rotor slot 17 and the motor flow are constant, the flow through the rotor slot 17 and the flow through the sealed cabin 18 always change with the load. When the drill bit leaves the bottom of the well, the motor load is approximately zero. At this time, the flow through the rotor slot 17 is the smallest, while the flow through the sealed cabin 18 is the largest. As the drill bit drills, the motor pressure difference increases continuously, which increases the flow through the rotor slot 17, while the flow through the sealed cabin 18 decreases.

[0031] 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 range of 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.

Claims

1. A low-speed short screw drill with adjustable flow, comprising a bypass valve assembly (1), characterized in that: A drain assembly (2) is disposed on one side of the bypass valve assembly (1), a motor assembly (3) is disposed on one side of the drain assembly (2), a transmission shaft assembly (4) is disposed on one side of the motor assembly (3), the bypass valve assembly (1) and the drain assembly (2), the drain assembly (2) and the motor assembly (3), and the motor assembly (3) and the transmission shaft assembly (4) are connected via threads, and the bypass valve assembly (1) and the drain assembly (2), the drain assembly (2) and the motor assembly (3), and the motor assembly (3) are connected via threads. A connection locking mechanism (16) is provided at the outer end of the connection position between the release assembly (3) and the transmission shaft assembly (4); an anti-drop joint (9) is provided at the outer end of the release assembly (2); an anti-drop connecting rod (8) is provided inside the anti-drop joint (9); one end of the anti-drop connecting rod (8) is fixedly connected to an anti-drop nut (10); a rotor (12) is provided inside the motor assembly (3); and a rotor through groove (17) is provided inside the anti-drop connecting rod (8), the anti-drop nut (10) and the rotor (12).

2. The low-speed short screw drill with adjustable flow rate according to claim 1, characterized in that: A valve sleeve (5) and a valve core (7) are installed inside the bypass valve assembly (1); the valve sleeve (5) is slidably connected to the bypass valve assembly (1); a spring is arranged between the valve sleeve (5) and the valve core (7); and a bypass groove (6) is provided on one side between the valve sleeve (5) and the valve core (7).

3. The low-speed short screw drill with adjustable flow rate according to claim 1, characterized in that: The outer end of the motor assembly (3) is provided with a stator (13), a sealed cabin (18) is provided inside the stator (13), the rotor (12) is meshedly connected with the sealed cabin (18), and the rotor (12) is fixedly connected with the anti-drop connecting rod (8).

4. The low-speed short screw drill with adjustable flow rate according to claim 1, characterized in that: A universal shaft (14) and a transmission shaft (15) are arranged inside the transmission shaft assembly (4); the rotor (12) is located on one side of the universal shaft (14); the transmission shaft (15) is connected to the transmission shaft (15) on the other side of the universal shaft (14); and the two ends of the universal shaft (14) are respectively connected to the rotor (12) and the transmission shaft (15) in transmission connection.

5. The low-speed short screw drill with adjustable flow rate according to claim 1, characterized in that: A first connecting sleeve (19) is provided at one end of the connecting and locking mechanism (16), and a second connecting sleeve (20) is provided at the other end of the connecting and locking mechanism (16). The first connecting sleeve (19) is respectively fixedly connected to one end of the bypass valve assembly (1) close to the discharge assembly (2), one end of the discharge assembly (2) close to the motor assembly (3), and one end of the motor assembly (3) close to the transmission shaft assembly (4). The second connecting sleeve (20) is respectively fixedly connected to one end of the discharge assembly (2) close to the bypass valve assembly (1), one end of the motor assembly (3) close to the discharge assembly (2), and one end of the transmission shaft assembly (4) close to the motor assembly (3).

6. The low-speed short screw drill with adjustable flow rate according to claim 5, characterized in that: A positioning block groove (11) is provided at the upper end of the first connecting sleeve (19) and the second connecting sleeve (20); a positioning block (21) is rotatably installed above the positioning block groove (11) of the first connecting sleeve (19); the positioning block (21) is adapted to and engaged with the positioning block groove (11) of the second connecting sleeve (20); and the positioning block (21) is an L-shaped structure.

7. The low-speed short screw drill with adjustable flow rate according to claim 6, characterized in that: A first positioning block groove (24) is provided inside one end of the positioning block (21), and a second positioning block groove (25) is provided inside the second connecting sleeve (20). The first positioning block groove (24) corresponds to the second positioning block groove (25). A locking block (22) is slidably provided inside the second positioning block groove (25). The locking block (22) is slidably connected to the first positioning block groove (24). First compression spring grooves (27) are symmetrically provided above and below the second positioning block groove (25). A positioning block retaining ring (26) is fixedly provided at the rear end of the locking block (22), and a first compression spring (28) is provided between the positioning block retaining ring (26) and the first compression spring groove (27).

8. The low-speed short screw drill with adjustable flow rate according to claim 7, characterized in that: A driving block groove (29) is provided above the rear side of the second positioning block groove (25), a driving block (23) is slidably arranged inside the driving block groove (29), the lower end of the driving block (23) and one end of the locking block (22) are inclined and have the same inclination angle, a limited rotation rod (30) is rotatably arranged inside the upper end of the driving block (23), and a limited rotation cap (31) is fixedly installed above the limited rotation rod (30).

9. The low-speed short screw drill with adjustable flow rate according to claim 8, characterized in that: Two limit bars (32) are slidably and symmetrically installed inside the limit rotating cap (31), and the limit bar (32) is an L-shaped structure. A telescopic rod (34) is arranged between the two limit bars (32), and a second compression spring (35) is sleeved on the outer side of the telescopic rod (34). The two ends of the second compression spring (35) are respectively fitted with the two limit bars (32), and the upper end of the limit bar (32) passes through and extends to the top of the limit rotating cap (31).

10. The low-speed short screw drill with adjustable flow rate according to claim 9, characterized in that: A limit strip groove (33) is arranged at the upper end of the driving block groove (29), and the limit strip groove (33) comprises a guide area (36), a vertical area (37) and a limit strip anti-slip groove (38), wherein the guide area (36) is located above the vertical area (37), and the limit strip anti-slip groove (38) is located below the vertical area (37), the diameter of the guide area (36) gradually decreases from top to bottom, the diameter of the vertical area (37) is the same as that of the guide area (36), and the diameter of the limit strip anti-slip groove (38) is larger than the diameter of the vertical area (37).

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