Mechanical seal-based explosion-proof screw pump direct-drive motor

Abstract

The application discloses an anti-explosion screw pump direct-drive motor based on mechanical sealing and belongs to the technical field of sealing equipment matched with oil exploitation, which comprises a base, an upper end cover arranged on the top surface of the base, a support fixedly installed on the bottom surface of the base, a bearing inner cover fixedly installed on the inner top surface of the base, and a transmission shaft rotatably installed in the base. The sealing seat is arranged and rotates synchronously with the pump body transmission shaft, the sealing sleeve and the sealing hollow tube are in a static state, the sealing gasket fills the end surface microscopic gap to form the first sealing barrier to block the leakage of the conveying medium to the inside of the device, the sealing oil in the sealing cavity forms a uniform lubricating liquid film under the action of the end surface relative movement, further blocks the leakage path to form the second sealing barrier, realizes zero leakage, avoids the waste of resources and the pollution of the environment caused by the leaked crude oil and associated gas, prolongs the service life of the polished rod, and reduces the maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of sealing technology for oil extraction equipment, specifically a direct-drive motor for an explosion-proof screw pump based on a mechanical seal. Background Technology

[0002] Screw pump direct drive motors are core drive equipment in oilfield downhole operations, widely used in crude oil lifting conditions of various sand-bearing, high-casing-pressure, and corrosive associated gas wells. For safety regulations, the wellhead drive components must be equipped with explosion-proof sealing structures to prevent the leakage of crude oil and flammable associated gas from the wellbore, avoiding the safety hazards of wellhead explosions and reducing resource losses and environmental pollution caused by oil and gas leaks. Currently, the mainstream sealing solutions in oilfields are divided into two categories: traditional packing seals and mechanical seals. Among them, mechanical seals, relying on the liquid film sealing mechanism formed by the friction pair of dynamic and static rings, have advantages such as low leakage, low friction loss, and adaptability to complex downhole conditions, and have gradually become the mainstream optimization direction for the sealing structure of explosion-proof screw pump equipment in oilfields.

[0003] In actual use, the packing seal of the above-mentioned device cannot achieve zero leakage. The leaked crude oil and associated gas not only waste resources and pollute the environment, but also pose a risk of combustion and explosion, which does not meet the requirements of explosion protection and environmental protection. Its hard friction will seriously wear down the polished rod, forming a vicious cycle and increasing maintenance costs. Summary of the Invention

[0004] The purpose of this invention is to provide a direct-drive motor for an explosion-proof screw pump based on a mechanical seal, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An explosion-proof screw pump direct drive motor based on a mechanical seal includes: a base, and an upper end cover is provided on the top surface of the base; The bracket is fixedly installed on the bottom surface of the machine base; The bearing inner cover is fixedly installed on the inner top surface of the machine base. A drive shaft is rotatably mounted inside the machine base; a guide rod clamp is fixedly sleeved on the outside of the drive shaft, and a clamping bushing is movably sleeved on the outside of the guide rod clamp; The lower positioning ring is located inside the machine base and is rotatably sleeved together with the drive shaft. The pin hole is located on the outer circular wall of the smooth rod clip. A cylindrical pin is fixedly engaged inside a pin hole. A sealed hollow tube is installed inside the drive shaft; The sealing component is located on the outside of the sealing hollow tube and is used to prevent crude oil and associated gas containing sand and corrosion from leaking out of the wellbore.

[0006] Preferably, the sealing component includes: A sealing sleeve is installed outside the sealing hollow tube and is threadedly connected to the sealing hollow tube. A sealing seat, which is rotatably mounted on the outside of a sealing sleeve; A sealing cavity is provided between the sealing seat and the sealing sleeve. Sealing oil is placed inside the sealing cavity.

[0007] Preferably, a spring cavity is provided between the sealing seat and the sealing sleeve, and several springs are fixedly installed on the bottom surface of the inner side of the spring cavity.

[0008] Preferably, the inner circular wall of the sealing seat is provided with a number of annular bosses, which together with the end face of the sealing sleeve form an annular microcavity.

[0009] Preferably, a first sealing ring is provided between the drive shaft and the guide rod clamp, and a second sealing ring is provided on the top surface of the first sealing ring.

[0010] Preferably, the outer circular wall of the drive shaft is provided with a keyway, and two keys are fixedly installed on the inner circular wall of the guide rod clamp, with the keyway and keys having an interference fit.

[0011] Preferably, a lower bearing seat is fixedly installed on the bottom surface of the base, a limit groove is opened inside the lower bearing seat, and a limit ring is fixedly sleeved on the outside of the sealing hollow tube, with the limit ring and the limit groove rotatably sleeved together.

[0012] Preferably, a detection hole is provided on the top surface of the bare rod clamp, and a liquid level conductivity sensor is fixedly installed inside the detection hole.

[0013] Preferably, a sealing gasket is fixedly adhered to the contact end face between the sealing seat and the sealing sleeve.

[0014] Preferably, a shock-absorbing washer is fixedly adhered to the bottom surface of the limiting ring.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. By setting a sealing seat, when the screw pump starts, the sealing seat rotates synchronously with the drive shaft, while the sealing sleeve and the sealing hollow tube remain stationary. Several springs arranged in the spring cavity apply a stable axial preload, pushing the mating end face of the sealing seat to fit tightly against the mating end face of the sealing sleeve. The sealing gasket fills the microscopic gaps between the two end faces, forming the first rigid sealing barrier in the initial stage of startup, blocking the leakage path of the conveyed medium to the inside of the device, and avoiding instantaneous leakage caused by the pressure impact of the medium at startup. As the equipment enters a stable operating state, the sealing seat and the sealing sleeve continue to rotate relative to each other. The sealing oil stored in the sealing cavity is evenly spread between the mating end faces by the traction of the relative movement of the end faces, forming a continuous and... A lubricating film with a certain load-bearing capacity is formed. On the one hand, the film fills the tiny dynamic gaps generated during the operation of the end faces, forming a second fluid sealing barrier to further block the leakage channels of the medium and enhance the overall sealing effect. On the other hand, it forms a stable fluid lubrication layer between the two end faces, avoiding direct contact between the hard mating surfaces, significantly reducing frictional resistance and frictional loss. At the same time, the sealing oil can continuously absorb the heat generated by the friction of the end faces and diffuse the heat outward through its own flow and heat conduction, controlling the operating temperature of the mating end faces within a reasonable and safe range. This prevents the deterioration of the conveyed medium or the performance degradation of the sealing components caused by high temperatures, achieving zero leakage and avoiding the waste of resources and environmental pollution caused by leaked crude oil and associated gas. It also improves the service life of the polished rod and reduces maintenance costs.

[0016] 2. By setting annular bosses, the first and second sealing rings are positioned between the drive shaft and the polished rod clamp, forming two independent sealing barriers. These barriers progressively block the leakage of the transported medium and associated oil and gas along the mating gap. When a single sealing ring experiences slight wear, the other sealing ring can still maintain its complete sealing performance, preventing the medium from directly leaking into the external environment. As the sealing seat rotates synchronously with the drive shaft, several annular bosses on its inner wall and the corresponding end faces of the sealing sleeve together form annular microcavities. Multiple sets of annular microcavities are arranged sequentially along the axial direction, forming a multi-level labyrinthine barrier path. This significantly extends the flow path of the leaking medium, increases the leakage resistance, and strengthens the radial sealing protection effect. At the same time, the annular microcavities can retain some sealing oil, continuously replenishing the lubricating oil film to the mating surface during the relative rotation of the end faces. This reduces the frictional resistance of the end faces, decreases the frictional temperature rise and component wear, and ensures that the entire device maintains stable transmission accuracy and sealing reliability throughout the entire operating cycle during long-term continuous operation, adapting to the long-term operation requirements under complex working conditions. Attached Figure Description

[0017] Figure 1 A three-dimensional structural diagram of a direct-drive motor for an explosion-proof screw pump based on a mechanical seal; Figure 2 This is a schematic cross-sectional view of the frame structure of a direct-drive motor in an explosion-proof screw pump based on a mechanical seal; Figure 3 This is a schematic diagram of a limiting ring structure in a direct-drive motor of an explosion-proof screw pump based on a mechanical seal; Figure 4 This is a schematic diagram of the sealing seat structure in a direct-drive motor of an explosion-proof screw pump based on a mechanical seal; Figure 5 This is a schematic cross-sectional view of the sealing sleeve in a direct-drive motor of an explosion-proof screw pump based on a mechanical seal. Figure 6 This is a schematic diagram of the planar structure of a sealed hollow tube in a direct-drive motor of an explosion-proof screw pump based on a mechanical seal; Figure 7 for Figure 5 A magnified schematic diagram of the local structure at point A in the middle.

[0018] In the diagram: 1. Base; 2. Upper end cover; 3. Bracket; 4. Bearing inner cover; 5. Smooth rod clip; 6. Drive shaft; 7. Lower positioning ring; 8. Sealing hollow tube; 9. Pin hole; 10. Cylindrical pin; 11. Sealing sleeve; 12. Sealing seat; 13. Sealing cavity; 14. Sealing oil; 15. Spring cavity; 16. Spring; 17. First sealing ring; 18. Second sealing ring; 19. Lower bearing seat; 20. Limiting groove; 21. Limiting ring; 22. Keyway; 23. Key; 24. Annular boss; 25. Annular microcavity; 26. Detection hole; 27. Liquid level conductivity sensor; 28. Sealing gasket; 29. ​​Shock-absorbing washer; 30. Clamping bushing. Detailed Implementation

[0019] Please see Figures 1 to 7 In this embodiment of the invention, an explosion-proof screw pump direct-drive motor based on a mechanical seal includes: a base 1, with an upper end cover 2 on the top surface of the base 1; a bracket 3, fixedly installed on the bottom surface of the base 1; a bearing inner cover 4, fixedly installed on the inner top surface of the base 1; a drive shaft 6, rotatably installed inside the base 1; a polished rod clamp 5, fixedly sleeved on the outside of the drive shaft 6, with a clamping bushing 30 movably sleeved on the outside of the polished rod clamp 5; a lower positioning ring 7, disposed inside the base 1, rotatably sleeved together with the drive shaft 6; a pin hole 9, formed on the outer circular wall of the polished rod clamp 5; a cylindrical pin 10, fixedly clamped inside the pin hole 9; a sealing hollow tube 8, disposed inside the drive shaft 6; and a sealing component, disposed outside the sealing hollow tube 8, used to prevent leakage of crude oil and associated gas containing sand corrosion from inside the wellbore. By setting a cylindrical pin 10, a bearing inner cover 4 is fixedly installed on the top surface inside the base 1. The bearing inner cover 4 forms an upper limit and protective isolation for the internal rotating structure of the base 1, preventing external impurities from entering the internal cavity of the base 1. The drive shaft 6 is rotatably assembled inside the base 1 and can stably perform circumferential rotation within the base 1, providing a power rotation basis for oil pumping operations. The polished rod clamp 5 has a pin hole 9, and the cylindrical pin 10 is fixedly engaged inside the pin hole 9. The cylindrical pin 10 and the pin hole 9 cooperate with each other to achieve circumferential fixation of the polished rod clamp 5 and the drive shaft 6, ensuring that both can be protected. The system maintains synchronous rotation to prevent slippage and freewheeling during operation. The clamping bushing 30 works in conjunction with the polished rod clamp 5 to clamp and fix the polished rod. It rotates synchronously with the polished rod clamp 5. The lower positioning ring 7 rotates in conjunction with the drive shaft 6 to constrain and correct the rotation state of the drive shaft 6. During equipment operation, external power drives the drive shaft 6 to rotate continuously. The drive shaft 6 drives the polished rod clamp 5 to rotate synchronously. The polished rod clamp 5 relies on the clamping bushing 30 to stably clamp the polished rod and complete the oilfield pumping operation. At the same time, the sealed hollow tube 8 works in conjunction with various sealing structures to operate continuously.

[0020] exist Figures 2-7 In the middle: the sealing components include: a sealing sleeve 11, which is disposed outside the sealing hollow tube 8 and is threadedly connected to the sealing hollow tube 8; a sealing seat 12, which is rotatably mounted outside the sealing sleeve 11; a sealing cavity 13, which is disposed between the sealing seat 12 and the sealing sleeve 11; a sealing oil 14, which is disposed inside the sealing cavity 13; a spring cavity 15 is provided between the sealing seat 12 and the sealing sleeve 11; a plurality of springs 16 are fixedly installed on the bottom surface of the inner surface of the spring cavity 15; and a sealing gasket 28 is fixedly adhered to the contact end face between the sealing seat 12 and the sealing sleeve 11. By setting the sealing seat 12, when the screw pump starts running, the sealing seat 12 rotates synchronously with the drive shaft 6, while the sealing sleeve 11 and the sealing hollow tube 8 remain stationary. Several springs 16 arranged in the spring cavity 15 apply a pre-stressing axial force, pushing the mating end face of the sealing seat 12 to tightly fit with the mating end face of the sealing sleeve 11. The sealing gasket 28 fills the microscopic gaps between the two end faces, forming the first rigid sealing barrier in the initial stage of startup, blocking the leakage path of the conveying medium to the inside of the device, and avoiding instantaneous leakage caused by the pressure impact of the medium at startup. As the equipment enters a stable operating state, the sealing seat 12 and the sealing sleeve 11 continue to rotate relative to each other, and the sealing cavity 13 stores... The sealing oil 14 is evenly spread between the mating end faces under the traction of the relative movement of the end faces, forming a continuous lubricating film with a certain load-bearing capacity. On the one hand, the liquid film fills the tiny dynamic gaps generated during the operation of the end faces, forming a second fluid sealing barrier, further blocking the leakage channels of the medium and strengthening the overall sealing effect. On the other hand, it forms a stable fluid lubrication layer between the two end faces, avoiding direct contact between the hard mating surfaces, greatly reducing frictional resistance and frictional loss. At the same time, the sealing oil 14 can continuously absorb the heat generated by the friction of the end faces, and diffuse the heat outward through its own flow and heat conduction, controlling the operating temperature of the mating end faces within a reasonable and safe range, preventing the deterioration of the conveyed medium or the performance degradation of the sealing components caused by high temperature. During long-term continuous operation of the equipment, the mating end face and the sealing gasket 28 will experience slight wear due to continuous friction. At this time, the spring 16 in the spring cavity 15 automatically releases its preload stroke, continuously pushing the sealing seat 12 towards the contact direction to compensate for displacement, thus maintaining the contact pressure between the end faces and the tightness of the sealing gasket 28. This ensures that the effectiveness of the first rigid sealing barrier does not decrease with the increase of wear, while ensuring that the end face gap is always within the effective coverage range of the sealing oil 14 liquid film, maintaining the stability and integrity of the second liquid film seal, and achieving automatic long-term maintenance of sealing performance. The threaded connection structure between the sealing sleeve 11 and the sealing hollow tube 8 provides a stable connection foundation for the stationary components, preventing loosening and displacement of components during operation, and ensuring that the fitting accuracy of each sealing component is always within the design range. The entire structure maintains a stable and reliable sealing effect throughout the entire operating cycle through a working mode that combines rigid end face sealing and fluid liquid film sealing, and coordinates elastic automatic compensation and lubrication temperature control. It is suitable for long-term continuous operation under complex working conditions such as impurities and weak corrosion.

[0021] exist Figures 5-6 In the middle: the inner circular wall of the sealing seat 12 is provided with several annular bosses 24, the annular bosses 24 and the end face of the sealing sleeve 11 form an annular microcavity 25, a first sealing ring 17 is provided between the drive shaft 6 and the light rod clamp 5, a second sealing ring 18 is provided on the top surface of the first sealing ring 17, a keyway 22 is provided on the outer circular wall of the drive shaft 6, and two keys 23 are fixedly installed on the inner circular wall of the light rod clamp 5, the keyway 22 and the keys 23 are interference fit; By setting the annular boss 24, after the screw pump starts running, the key 23 is embedded in the keyway 22 and forms an interference fit, so that the drive shaft 6 and the smooth rod clamp 5 keep rotating synchronously in the circumference. There is no relative slippage or circumferential movement in the torque transmission process, ensuring precise and consistent transmission action. The first sealing ring 17 and the second sealing ring 18 are set between the mating gap of the drive shaft 6 and the smooth rod clamp 5, forming two independent sealing barriers, which progressively block the leakage of the conveyed medium and associated oil and gas along the mating gap. When a single sealing ring experiences slight wear, the other sealing ring can still maintain complete sealing performance, preventing the medium from directly leaking to the external environment. During the synchronous rotation of the sealing seat 12 with the transmission shaft 6, several annular protrusions 24 on its inner wall and the corresponding end faces of the sealing sleeve 11 together form an annular microcavity 25. Multiple sets of annular microcavities 25 are arranged sequentially along the axial direction, forming a multi-level labyrinthine barrier path, which greatly extends the flow path of medium leakage, increases the resistance to medium leakage, and strengthens the radial sealing protection effect. At the same time, the annular microcavity 25 can retain some sealing oil 14, which continuously replenishes the lubricating oil film to the mating surface during the relative rotation of the end faces, reduces the frictional resistance of the end faces, reduces the frictional temperature rise and the amount of component wear. During long-term continuous operation, the interference fit key 23 and keyway 22 always maintain a clearance-free transmission state, avoiding uneven wear of the sealing components caused by transmission impact. The double sealing rings continuously maintain the auxiliary sealing performance, and together with the labyrinth barrier and lubrication replenishment function of the annular microcavity 25, they jointly ensure that the entire device maintains stable transmission accuracy and sealing reliability throughout the entire operating cycle, adapting to the long-term operation requirements under complex working conditions.

[0022] exist Figures 3-4 In the middle: A lower bearing seat 19 is fixedly installed on the bottom surface of the base 1. A limit groove 20 is opened inside the lower bearing seat 19. A limit ring 21 is fixedly sleeved on the outside of the sealing hollow tube 8. The limit ring 21 and the limit groove 20 are rotatably sleeved together. A shock-absorbing washer 29 is fixedly adhered to the bottom surface of the limit ring 21. A detection hole 26 is opened on the top surface of the smooth rod clip 5. A liquid level conductivity sensor 27 is fixedly installed inside the detection hole 26. A sealing gasket 28 is fixedly adhered to the contact end face between the sealing seat 12 and the sealing tube sleeve 11. By setting a limiting ring 21, which fits into the limiting groove 20 to form a radial limiting constraint, the sealing hollow tube 8 is positioned circumferentially and radially, maintaining the coaxial fit accuracy between the sealing hollow tube 8 and the rotating sealing component, and avoiding problems such as uneven wear and gaps in the sealing pair caused by component misalignment. The shock-absorbing washer 29 is fitted with the limiting ring 21 to absorb the axial vibration and alternating impact load generated during equipment operation, weakening the transmission of vibration energy to the sealing end face, and avoiding end face instability and media leakage caused by vibration. When the sealing seat 12 and the sealing sleeve 11 rotate relative to each other, the sealing gasket 28 fills the microscopic uneven gaps between the two end faces, forming a stable end face sealing barrier, blocking the leakage channel of the conveyed medium along the mating end face, and working together with the liquid film structure formed by the internal sealing oil 14 to form a multi-layer sealing protection system. The liquid level and conductivity sensor 27 is installed through the detection hole 26 to monitor the leakage status of the medium inside the device in real time. When the sealing component is worn or the medium leaks slightly, the liquid level and conductivity sensor 27 can quickly identify the changes in liquid level and fluctuations in the medium conductivity parameters, trigger an early warning signal, and realize early prediction and timely handling of sealing failure.

[0023] The working principle of this invention is: After external power input, the drive shaft 6 enters a circumferential rotation state. The cylindrical pin 10 and the pin hole 9 form a circumferential locking fit. The key 23 and the keyway 22 transmit torque through an interference fit, driving the polished rod clamp 5 to rotate synchronously with the drive shaft 6. The clamping bushing 30 rotates synchronously with the polished rod clamp 5, completing the polished rod clamping and fixing and power output, providing stable power for oil pumping operations. The bearing inner cover 4 and the lower positioning ring 7 together constrain the rotation trajectory of the drive shaft 6 and correct the rotational coaxiality. The upper end cover 2 and the bracket 3 provide external protection and load-bearing support for the entire device.

[0024] The sealing seat 12 rotates synchronously with the drive shaft 6, while the sealing sleeve 11 and the sealing hollow tube 8 remain stationary, forming a continuous relative rotation. The spring 16 inside the spring cavity 15 continuously outputs a stable axial preload, ensuring a tight fit between the mating end faces of the sealing seat 12 and the sealing sleeve 11. The sealing gasket 28 fills the microscopic gaps between the end faces, forming the first rigid sealing barrier and blocking the leakage path of the conveyed medium to the inside of the device. The sealing oil 14 in the sealing cavity 13 is evenly spread between the mating end faces under the traction of the relative movement of the end faces, forming a continuous lubricating film with load-bearing capacity, constituting the second fluid sealing barrier, further sealing the leakage channel; at the same time, the sealing oil 14 forms a fluid lubrication layer between the end faces, avoiding direct contact between hard end faces, reducing frictional resistance and frictional loss, and continuously absorbing the heat generated by friction, controlling the operating temperature of the mating end faces within a safe range.

[0025] The annular boss 24 rotates synchronously with the sealing seat 12 and cooperates with the sealing sleeve 11 to form multiple sets of annular microcavities 25. The multiple sets of annular microcavities 25 are arranged sequentially along the axial direction to form a multi-level labyrinth-like barrier path, which greatly extends the medium leakage path, increases leakage resistance, and strengthens the sealing protection effect. At the same time, the annular microcavities 25 can retain some sealing oil 14, and continuously replenish the lubricating oil film to the mating end face during relative rotation, ensuring the continuity and stability of the liquid film.

[0026] During long-term continuous operation of the equipment, the mating end face and the sealing gasket 28 will experience slight wear due to continuous friction. The spring 16 will automatically release the preload stroke and push the sealing seat 12 to compensate for the displacement in the mating direction. This will maintain the mating pressure between the end faces and the tightness of the sealing gasket 28, ensuring that the effectiveness of the first rigid sealing barrier does not decrease with increased wear. At the same time, it will ensure that the end face gap is always within the effective coverage range of the sealing oil 14 liquid film, maintaining the stability of the second fluid sealing barrier and achieving automatic long-term maintenance of sealing performance.

[0027] The first sealing ring 17 and the second sealing ring 18 form two independent auxiliary sealing barriers, progressively preventing the leakage of the conveyed medium and associated oil and gas along the fit gap between the drive shaft 6 and the smooth rod clamp 5. Even if one sealing ring experiences slight wear, the other sealing ring can still maintain complete sealing performance, preventing direct leakage of the medium. The limiting ring 21 and the limiting groove 20 cooperate to form radial constraints, ensuring the coaxial fit accuracy of the sealing hollow tube 8 and preventing uneven wear caused by misalignment of the sealing components. The vibration damping washer 29 absorbs the axial vibration and alternating impact loads generated during equipment operation, weakening the transmission of vibration energy to the sealing end face and preventing end face instability and medium leakage caused by vibration. The lower bearing seat 19 provides a rigid support foundation for the limiting and vibration damping structure, ensuring the operational stability of the support structure.

[0028] The liquid level and conductivity sensor 27 collects the liquid level and conductivity parameters inside the device in real time through the detection hole 26. When the sealing component is worn or the medium leaks slightly, the liquid level and conductivity sensor 27 quickly identifies the parameter changes and triggers an early warning signal, realizing early prediction and timely handling of sealing failure, and avoiding the expansion of leakage and the occurrence of safety hazards.

[0029] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A direct-drive motor for an explosion-proof screw pump based on a mechanical seal, characterized in that, include: A base (1) is provided with an upper end cover (2) on its top surface; The bracket (3) is fixedly installed on the bottom surface of the base (1); The bearing inner cover (4) is fixedly installed on the inner top surface of the base (1); A drive shaft (6) is rotatably mounted inside the base (1); A smooth rod clip (5) is fixedly sleeved on the outside of the transmission shaft (6), and a clamping bushing (30) is movably sleeved on the outside of the smooth rod clip (5). The lower positioning ring (7) is disposed inside the machine base (1) and is rotatably sleeved together with the transmission shaft (6); Pin hole (9) is formed on the outer circular wall surface of the bare rod clip (5); A cylindrical pin (10) is fixedly engaged inside the pin hole (9); A sealed hollow tube (8) is disposed inside the drive shaft (6); A sealing component is disposed outside the sealing hollow tube (8) to prevent crude oil and sand-containing corrosive gas from leaking out of the wellbore.

2. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 1, characterized in that, The sealing component includes: A sealing sleeve (11) is disposed outside the sealing hollow tube (8) and is threadedly connected to the sealing hollow tube (8). A sealing seat (12) is rotatably mounted on the outside of the sealing sleeve (11); A sealing cavity (13) is provided between the sealing seat (12) and the sealing sleeve (11); Sealing oil (14) is disposed inside the sealing cavity (13).

3. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 2, characterized in that, A spring cavity (15) is provided between the sealing seat (12) and the sealing sleeve (11), and a number of springs (16) are fixedly installed on the bottom surface of the inner side of the spring cavity (15).

4. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 2, characterized in that, The inner circular wall of the sealing seat (12) is provided with a number of annular bosses (24), and the annular bosses (24) and the end face of the sealing sleeve (11) form an annular microcavity (25).

5. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 2, characterized in that, A first sealing ring (17) is provided between the drive shaft (6) and the light rod clamp (5), and a second sealing ring (18) is provided on the top surface of the first sealing ring (17).

6. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 1, characterized in that, The outer circular wall of the drive shaft (6) is provided with a keyway (22), and two keys (23) are fixedly installed on the inner circular wall of the optical rod clip (5). The keyway (22) and the keys (23) are interference fit.

7. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 2, characterized in that, The bottom surface of the base (1) is fixedly installed with a lower bearing seat (19). A limiting groove (20) is opened inside the lower bearing seat (19). A limiting ring (21) is fixedly sleeved on the outside of the sealed hollow tube (8). The limiting ring (21) and the limiting groove (20) are rotatably sleeved together.

8. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 1, characterized in that, The top surface of the optical rod clip (5) is provided with a detection hole (26), and a liquid level conductivity sensor (27) is fixedly installed inside the detection hole (26).

9. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 3, characterized in that, A sealing gasket (28) is fixedly adhered to the contact end face between the sealing seat (12) and the sealing sleeve (11).

10. The explosion-proof screw pump direct-drive motor based on a mechanical seal according to claim 7, characterized in that, The bottom surface of the limiting ring (21) is fixedly bonded with a shock-absorbing washer (29).

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