Disclosed are a disc-screw pump ground drive device with a built-in brake device and a braking method.

Abstract

The application discloses a disc-shaped screw pump ground driving device with a built-in brake device and a brake method, and belongs to the field of oil exploitation equipment. The device solves the problem of equipment damage or safety accidents caused by rapid reverse rotation of the sucker rod when the screw pump stops. The device comprises square clamps, a disc-shaped permanent magnet motor, a brake device, a bearing box and a sucker rod. The disc-shaped permanent magnet motor comprises a main shaft, and the top of the main shaft is connected with the top of the sucker rod through the square clamps. The brake device comprises a brake disc, rollers and an O-shaped ring. The brake disc is coaxially sleeved on the main shaft, a plurality of long-hole holes for placing the rollers are formed in the inner wall of the brake disc in the circumferential direction, the O-shaped ring is embedded in the brake disc, the inner side wall of the O-shaped ring is in contact with the surface of the roller, the outer wall of the brake disc is connected with the inner wall of the bearing box, and damping grease is filled in the contact surface between the brake disc and the bearing box. The device is mainly used for preventing the reverse rotation of the sucker rod column when the ground driving device stops.

Description

Technical Field

[0001] This invention belongs to the field of oil extraction equipment technology, and in particular relates to a ground drive device and braking method for a disc screw pump with a built-in braking device. Background Technology

[0002] In oilfield production operations, the surface drive unit is the core equipment of the screw pump production system. The surface drive unit drives the sucker rod to rotate, which in turn drives the rotor of the downhole screw pump, thereby lifting the well fluid to the surface. When the drive unit stops, the liquid column in the tubing and casing generates significant potential energy due to the liquid level difference. During operation, the torsional deformation energy accumulated in the sucker rod is released instantaneously. The superposition of these two energies will drive the sucker rod and the main shaft of the connected surface unit to reverse rapidly. If this violent reversal is not controlled, it can easily cause the threaded connection of the sucker rod to loosen, leading to a rod string falling into the well. It can also cause impact damage to the surface transmission components and even threaten the personal safety of the on-site operators.

[0003] Currently, ratchet-pawl anti-reverse mechanism is commonly used in the surface drive units of oilfield screw pumps. This type of mechanism typically utilizes the unidirectional rotational characteristics of the ratchet and pawl to achieve the anti-reverse function. The pawl is mounted on a fixed component via a pin and can rotate around the pin. It usually employs an external engagement mechanism, relying on the preload of a torsion spring to ensure rapid engagement between the pawl and ratchet when the pump stops. When the drive unit is operating normally, the ratchet rotates forward with the main shaft, and the pawl bounces on the ratchet teeth. At the moment of stopping, under the spring force, the pawl quickly engages with the ratchet teeth, preventing the main shaft from reversing and thus locking the reverse torque stored in the sucker rod. In the low-speed operation phase of this traditional ratchet-pawl anti-reverse device, the repeated contact, impact, and slippage between the pawl and ratchet teeth generate continuous meshing noise and cause material wear at the contact points. Long-term use affects the reliability of the device and requires maintenance. Furthermore, when the system's stored reverse torque needs to be released after shutdown, it must be manually operated by a person at close range. If this operation is improper, or if components such as the brake band that the device relies on slip or fail during the release process, the huge accumulated torque may be released instantly, causing the operating handle to spin wildly or components to break, posing a serious safety threat to nearby operators. Summary of the Invention

[0004] In view of this, the present invention aims to provide a ground drive device and braking method for a disc screw pump with a built-in braking device, so as to solve the problem of equipment damage or safety accidents caused by the rapid reversal of the sucker rod when the screw pump stops.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a ground drive device for a disc screw pump with a built-in braking device, comprising a square clamp, a disc permanent magnet motor, a braking device, a bearing housing, and a sucker rod; the disc permanent magnet motor includes a main shaft, the main shaft being located at the central axis of the disc permanent magnet motor, the main shaft being sleeved on the outside of the sucker rod, and the top of the main shaft being connected to the top of the sucker rod via the square clamp; the braking device includes a brake disc, rollers, and an O-ring, the brake disc being coaxially sleeved on the main shaft, and the inner... Multiple elongated holes for placing rollers are opened along the circumferential direction of the wall. The width of the elongated holes gradually decreases along the reverse direction of the main shaft. The O-ring is embedded in the brake disc. The inner sidewall of the O-ring contacts the surface of the roller. The outer contour of the brake disc is a conical surface. The bearing housing is located below the disc permanent magnet motor. The top of the inner wall of the bearing housing is provided with a conical surface that matches the outer contour of the brake disc. The brake disc is supported on the conical surface at the top of the inner wall of the bearing housing by the conical surface of the outer contour. The contact surface between the brake disc and the bearing housing is filled with damping grease.

[0006] Furthermore, the braking device also includes an upper cover and a lower cover, which are respectively connected to the upper and lower sides of the brake disc by screws.

[0007] Furthermore, the disc screw pump ground drive device with built-in braking device also includes a sealing sleeve sleeved on the outside of the sucker rod. The top of the sealing sleeve is provided with a square seat, and the top of the main shaft is provided with a first groove. The main shaft is sleeved on the outside of the sealing sleeve, and the sealing sleeve is engaged with the first groove through the square seat. The bottom of the square clip is provided with a second groove, and the square clip is engaged with the square seat through the second groove. There are two square clips, and the two square clips are connected by bolts to lock the sucker rod.

[0008] Furthermore, the sealing sleeve includes a lock nut, a packing gasket, a central tube, a PTFE oil seal, and a gland. The central tube has grooves at its top and bottom. The packing gasket is placed in the groove at the top of the central tube and is fixed by the lock nut. The PTFE oil seal is placed in the groove at the bottom of the central tube and is fixed by the gland. The sealing sleeve has a lower sealing assembly at its bottom.

[0009] Furthermore, the lower sealing assembly includes a wear-resistant seat, a fastening seat, and a mounting seat. The top of the wear-resistant seat is connected to the central tube, and the bottom is provided with a mounting seat. The mounting seat and the wear-resistant seat are connected by a fastening seat. An elastic pad is provided at the connection between the wear-resistant seat and the fastening seat, and a well sealer is provided at the bottom of the mounting seat.

[0010] Furthermore, the fastening seat is a ring structure with an internal thread on the inner side, and the mounting seat has an external thread on its outer surface. The fastening seat and the mounting seat are connected by threads.

[0011] Furthermore, the disc-type permanent magnet motor also includes a housing, a rotor, and a stator. The rotor and stator are both disposed inside the housing. The rotor is sleeved outside the main shaft. The stator is sleeved outside the rotor. The outer side of the stator is connected to the inner wall of the housing. The housing includes an upper end cover, an outer shell, and a lower end cover. The upper end cover and the lower end cover are respectively connected to the upper and lower surfaces of the outer shell by bolts.

[0012] Furthermore, the disc-type permanent magnet motor is equipped with a junction box, which is fixed to the outer casing by bolts.

[0013] Furthermore, the main shaft is a stepped shaft, and a deep groove ball bearing and a thrust self-aligning bearing are installed in the bearing housing. The outer rings of the deep groove ball bearing and the thrust self-aligning bearing are in contact with the inner wall of the bearing housing, and the inner rings are in contact with the outer wall of the main shaft. The deep groove ball bearing and the thrust self-aligning bearing are fixed by the steps of the main shaft.

[0014] A braking method for a disc screw pump ground drive device with a built-in braking device includes the following steps:

[0015] When the disc permanent magnet motor stops or needs to be braked, under the friction and elastic pressure of the O-ring, the roller moves to the narrow end of the elongated hole. At this time, the roller wedges between the outer surface of the main shaft and the inner wall of the narrow end of the elongated hole, locking the main shaft and the brake disc. The damping grease between the brake disc and the bearing housing slows down the reverse speed, thereby preventing the sucker rod from reversing.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. This invention achieves efficient and stable automatic control and torque release through a built-in braking device, significantly improving the safety of the surface drive device. Through the adaptive displacement and wedging effect of the rollers in the long hole of the braking device, and the filling of damping grease at the contact surface between the brake disc and the bearing box, the braking function is automatically triggered the moment the motor stops. This process does not require manual intervention and can lock the main shaft and use the viscosity of the damping grease to release the huge reverse torque stored in the sucker rod smoothly and controllably. This fundamentally avoids the safety threats to operators caused by improper operation or brake band slippage when manually releasing torque in traditional anti-reverse devices, such as component over-rotation and breakage. The braking device can suppress the reverse rotation of the sucker rod in the first place, fundamentally eliminating the risk of rod string disengagement and equipment damage due to reverse impact, providing inherent safety protection for downhole rod string and surface equipment.

[0018] 2. This invention effectively extends the life of the sealing system by setting a sealing sleeve and a lower sealing assembly. By setting a PTFE oil seal, wear resistance and corrosion resistance are improved, thereby increasing the service life of the sealing components at the dynamic seal. Furthermore, the cooperation between the wear-resistant seat and the elastic pad compensates for the alignment error during installation, ensuring that the sealing components maintain good concentricity during dynamic operation, avoiding uneven wear and early failure caused by misalignment, and further ensuring the long-term stability of the sealing effect.

[0019] 3. In this invention, the rollers and the main shaft are in sliding contact or have a gap. During normal forward rotation of the device, the noise and mechanical wear caused by continuous impact and meshing at low speeds are avoided. This not only improves the working environment but also reduces maintenance needs due to component wear, extends the service life of the braking device, and improves the overall reliability and economy of the equipment.

[0020] 4. This invention uses a disc-type permanent magnet motor for power, which is more energy-efficient than the traditional vertical permanent magnet motor and has higher speed control precision. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 This is a first-view axial side structural schematic diagram of a disc screw pump ground drive device with built-in braking device according to the present invention.

[0023] Figure 2 This is a second-view axial side structural diagram of a disc screw pump ground drive device with a built-in braking device according to the present invention.

[0024] Figure 3 This is a cross-sectional view of a disc screw pump ground drive device with a built-in braking device according to the present invention.

[0025] Figure 4 This is a schematic diagram of the shaft side structure of the brake device of the disc screw pump ground drive device with built-in brake device according to the present invention;

[0026] Figure 5 This is a cross-sectional structural diagram of the braking device of a disc screw pump ground drive device with built-in braking device according to the present invention;

[0027] Figure 6 This is a top view schematic diagram of the braking device of a disc screw pump ground drive device with built-in braking device according to the present invention;

[0028] Figure 7This is a partial cross-sectional schematic diagram of the sealing sleeve and lower sealing assembly of a disc screw pump ground drive device with a built-in braking device according to the present invention.

[0029] Figure 8 This is a schematic diagram of the shaft-side structure of a disc permanent magnet motor without a main shaft in a disc screw pump ground drive device with a built-in braking device according to the present invention.

[0030] Figure 9 This is a schematic front cross-sectional view of a disc-type permanent magnet motor without a main shaft in a disc screw pump ground drive device with a built-in braking device according to the present invention.

[0031] In the picture:

[0032] 1. Square clamp; 2. Sealing sleeve; 3. Disc permanent magnet motor; 4. Braking device; 5. Bearing housing; 6. Deep groove ball bearing; 7. Thrust self-aligning bearing; 8. Lower sealing assembly; 9. Well sealer; 10. Sucker rod; 11. Junction box; 12. Lock nut; 13. Packing gasket; 14. Center tube; 15. PTFE oil seal; 16. Pressure cap; 17. Upper end cap; 18. Housing; 19. Rotor; 20. Stator; 21. Lower end cap; 22. Main shaft; 23. Screw; 24. Upper cover; 25. Brake disc; 26. Roller; 27. O-ring; 28. Lower cover; 29. ​​Wear-resistant seat; 30. Fastening seat; 31. Elastic pad; 32. Mounting seat. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0034] Detailed implementation method: See Figure 1-9This embodiment describes a ground drive device for a disc screw pump with a built-in braking device, comprising a square clamp 1, a disc permanent magnet motor 3, a braking device 4, a bearing housing 5, and a sucker rod 10. The disc permanent magnet motor 3 includes a main shaft 22 located at its central axis. The main shaft 22 is sleeved on the outside of the sucker rod 10, and its top is connected to the top of the sucker rod 10 via the square clamp 1. The square clamp 1 connects the sucker rod 10 and the main shaft 22, and transmits the rotational torque generated by the main shaft 22 to the sucker rod 10. The disc permanent magnet motor 3 serves as the drive source, providing the rotational force required by the screw pump. Compared to traditional vertical motors, the disc permanent magnet motor 3 is more efficient... Energy-saving and with a more compact structure, the main shaft 22 is used to transmit torque. The sucker rod 10 is connected to the screw pump rotor downhole. The rotational force generated by the disc permanent magnet motor 3 is transmitted to the screw pump rotor downhole through the sucker rod 10, thereby lifting the crude oil to the surface. The braking device 4 includes a brake disc 25, rollers 26, and O-rings 27. The brake disc 25 is coaxially sleeved on the main shaft 22. The inner wall of the brake disc 25 has multiple elongated holes along the circumferential direction for placing the rollers 26. The width of the elongated holes gradually decreases along the reverse direction of the main shaft. The O-rings 27 are embedded in the brake disc 25. The inner sidewall of the O-ring 27 is in contact with the surface of the rollers 26. The outer contour of the brake disc 25 is tapered. The braking device 4 is used to prevent the sucker rod 10 from rapidly reversing due to the release of potential energy when the machine stops. The elongated hole on the brake disc 25 is used to accommodate the roller 26. One end of the elongated hole is wide and the other end is narrow. The brake disc 25 is used to cooperate with the bearing housing 5 to generate braking force. The O-ring 27 is used to provide continuous elastic preload pressure for the roller 26, ensuring that the roller 26 can quickly and reliably wedge into the narrow end of the elongated hole when braking is required. The conical surface of the brake disc 25 and the bearing housing 5 form a braking pair. The bearing housing 5 is located below the disc permanent magnet motor 3. The top of the inner wall of the bearing housing 5 is provided with a conical surface that cooperates with the outer contour of the brake disc 25. The bearing housing 5 serves as the lower end of the main shaft 22. The supporting structure provides rotational support for the main shaft 22. The conical surface at the top of the inner wall of the bearing housing 5 cooperates with the brake disc 25 to form a braking friction pair. The brake disc 25 is supported on the conical surface at the top of the inner wall of the bearing housing 5 by the conical surface of its outer contour, thereby generating frictional torque, which provides a basis for efficient braking. The contact surface between the brake disc 25 and the bearing housing 5 is filled with damping grease. Utilizing the inherent viscosity of the damping grease, when the brake disc 25 and the bearing housing 5 move relative to each other, shear resistance is generated, so that the reverse torque generated by the sucker rod 10 is released smoothly and slowly. The damping grease is refined by a special process using special high-molecular base oil and high-purity thickener, with the addition of rust-proof, waterproof, and corrosion-resistant additives.

[0035] The disc screw pump ground drive device of the present invention adopts a disc permanent magnet motor 3. The disc permanent magnet motor 3 is more efficient and energy-saving than traditional motors. The brake device 4 set inside the drive device uses damping grease to provide friction, which can slowly release the reverse torque of the sucker rod 10 after the disc permanent magnet motor 3 stops, preventing the sucker rod 10 from rapidly reversing and causing disengagement, thereby ensuring the safety of the equipment and the safety of the operators.

[0036] The braking device 4 also includes an upper cover 24 and a lower cover 28. The upper cover 24 and the lower cover 28 are respectively connected to the upper and lower sides of the brake disc 25 by screws 23. The screws 23 are used to connect and fix the upper cover 24 and the lower cover 28. The upper cover 24 and the lower cover 28 are used to prevent the internal rollers 26 from falling off.

[0037] The disc screw pump ground drive device with built-in braking device also includes a sealing sleeve 2 sleeved on the outside of the sucker rod 10. A square seat is provided at the top of the sealing sleeve 2, and a first groove is provided at the top of the main shaft 22. The main shaft 22 is sleeved on the outside of the sealing sleeve 2 and engages with the first groove via the square seat. A second groove is provided at the bottom of the square clip 1, and the square clip 1 engages with the square seat via the second groove. There are two square clips 1, which are bolted together to lock the sucker rod 10. Semi-circular arc surfaces are symmetrically arranged between the two square clips 1. The top is confined within the arc surface between the two square clips 1. The square clips 1 are fixed to the top of the sucker rod 10 by locking bolts. When the main shaft 22 rotates, the main shaft 22 drives the sealing sleeve 2 to rotate through the square seat at the top of the sealing sleeve 2. At the same time, the square seat at the top of the sealing sleeve 2 drives the square clips 1 to rotate. The square clips 1 transmit the rotational motion to the sucker rod 10, thereby realizing the oil production operation. The torque is transmitted through the rectangular mating surface between the square seat and the square clips 1. Dynamic sealing is achieved through the fitted sealing sleeve 2. The quick clamping and loosening function of the square clips 1 enables convenient assembly and disassembly of the sucker rod 10.

[0038] This invention uses a square clamp 1 to lock the sucker rod 10, starts the disc-type permanent magnet motor 3, and rotates the main shaft 22, which in turn drives the square clamp 1 to rotate. The square clamp 1 drives the sucker rod 10 to rotate, completing the oil extraction operation. The braking device adopts the principle of one-way bearing. When the main shaft 22 rotates clockwise, the roller 26 is located in the wide section of the elongated hole and does not rotate. When the main shaft 22 rotates counterclockwise, the roller 26 slides to the narrow end of the elongated hole. Under the squeezing action of the O-ring 27, the roller 26 always moves towards the center. At this time, the roller 26 contacts the main shaft 22, and the main shaft 22 transmits power to the roller 26 and drives the brake disc 25 to rotate. The damping grease applied to the contact surface between the brake disc 25 and the bearing housing 5 plays a buffering role and slows down the reverse speed.

[0039] See Figure 7-8In this embodiment, the sealing sleeve 2 includes a lock nut 12, a packing gasket 13, a central tube 14, a PTFE oil seal 15, and a gland 16. The central tube 14 has grooves at its top and bottom. The packing gasket 13 is disposed in the groove at the top of the central tube 14 and is fixed by the lock nut 12. The PTFE oil seal 15 is disposed in the groove at the bottom of the central tube 14 and is fixed by the gland 16. The sealing sleeve 2 has a lower sealing assembly 8 at its bottom. The inner wall of the top of the central tube 14 has threads, and the lock nut 12 is connected to the central tube 14 via these threads. The lock nut 12 is used for... The packing gasket 13 is tightened to achieve a primary seal between the main shaft 22 and the center tube 14. The center tube 14 is used to install and accommodate the lock nut 12, the packing gasket 13, the PTFE oil seal 15, and the gland 16. The PTFE oil seal 15 utilizes the wear-resistant and corrosion-resistant properties of PTFE material to achieve a dynamic seal between the main shaft 22 and the center tube 14. The PTFE oil seal 15 can be one or more. The gland 16 is used to fix and tighten the bottom PTFE oil seal 15 to prevent axial movement of the PTFE oil seal 15. The lower sealing assembly 8 is located below the sealing sleeve 2 to achieve a seal between the main shaft 22 and the wellhead device.

[0040] The lower sealing assembly 8 includes a wear-resistant seat 29, a fastening seat 30, and a mounting seat 32. The top of the wear-resistant seat 29 is connected to the central tube 14, and the bottom is provided with the mounting seat 32. The mounting seat 32 and the wear-resistant seat 29 are connected by the fastening seat 30. An elastic pad 31 is provided at the connection between the wear-resistant seat 29 and the fastening seat 30. A wellhead sealer 9 is provided at the bottom of the mounting seat 32. The elastic pad 31 is a rubber pad. The wear-resistant seat 29 and the main shaft 22 form a dynamic seal. The fastening seat 30 is used to provide and maintain the clamping force. The fastening seat 30 presses the upper wear-resistant seat 29, elastic pad 31, and mounting seat 32 into a whole, ensuring a tight connection between the components. The elastic pad 31 is used to provide radial floating compensation capability, ensuring that the wear-resistant seat 29 and the main shaft 22 always maintain a uniform gap, thereby avoiding local wear caused by misalignment. The mounting seat 32 is the base of the lower sealing assembly 8, and the wellhead sealer 9 is a blowout preventer at the wellhead.

[0041] The sealing device of the present invention includes a sealing sleeve 2 and a lower sealing assembly 8. One or more PTFE oil seals 15 are provided at the bottom of the sealing sleeve 2. The use of PTFE oil seals 15 improves the service life of the sealing sleeve 2. In order to address the concentricity problem of the equipment, the lower sealing assembly 8 is designed. Through the action of the elastic pad 31, the concentricity of the ground drive device of the disc screw pump is ensured, avoiding the problem of sealing device damage caused by eccentricity, thereby improving the service life of the sealing device.

[0042] The fastening seat 30 has an annular structure and an internal thread on its inner side. The mounting seat 32 has an external thread on its outer surface. The fastening seat 30 and the mounting seat 32 are connected by threads. By rotating the fastening seat 30, the installation height of the entire lower sealing assembly 8 can be precisely adjusted to ensure that the lower sealing assembly 8 is accurately aligned with the upper sealing sleeve 2.

[0043] To ensure the concentricity of the sealing components and extend their service life, when installing the ground drive unit of the disc screw pump, first loosen the fastening seat 30 to allow the wear-resistant seat 29 to move horizontally. Then, by slowly rotating the motor, the wear-resistant seat 29 automatically adjusts to a concentric position under the rotation of the PTFE oil seal 15. Then tighten the fastening seat 30 and use PTFE as the sealing material for the PTFE oil seal 15. Under the action of the elastic pad 31, the concentricity of the device is ensured, thereby solving the problem of short service life of the lower seal 8 and sealing sleeve 2 caused by eccentricity.

[0044] See Figure 8-9 In this embodiment, the disc-type permanent magnet motor 3 further includes a housing, a rotor 19, and a stator 20. The rotor 19 and the stator 20 are both disposed inside the housing. The rotor 19 is sleeved on the outside of the main shaft 22, and the stator 20 is sleeved on the outside of the rotor 19. The outside of the stator 20 is connected to the inner wall of the housing. The housing includes an upper end cover 17, an outer shell 18, and a lower end cover 21. The upper end cover 17 and the lower end cover 21 are respectively connected to the upper and lower surfaces of the outer shell 18 by bolts. The upper end cover 17 and the lower end cover 21 serve to seal and support. The outer shell 18 is used to accommodate the rotor 19 and the stator 20 and to fix the stator 20. The rotor 19 can generate rotational force under the action of a magnetic field, thereby driving the main shaft 22 to rotate. The stator 20 generates a rotating magnetic field to drive the rotor 19.

[0045] The disc-type permanent magnet motor 3 is provided with a junction box 11, which is fixed to the outer casing 18 by bolts. The junction box 11 is used to introduce and connect the power cable and control circuit of the disc-type permanent magnet motor 3.

[0046] The main shaft 22 is a stepped shaft. A deep groove ball bearing 6 and a thrust self-aligning bearing 7 are installed in the bearing housing 5. The outer rings of the deep groove ball bearing 6 and the thrust self-aligning bearing 7 are in contact with the inner wall of the bearing housing 5, and the inner rings are in contact with the outer wall of the main shaft 22. The deep groove ball bearing 6 and the thrust self-aligning bearing 7 are fixed by the steps of the main shaft 22. The deep groove ball bearing 6 is mainly used to bear the radial load of the main shaft 22 and ensure the concentricity of the rotation of the main shaft 22. The thrust self-aligning bearing 7 is mainly used to bear the axial load generated when the sucker rod 10 is working.

[0047] A braking method for a disc screw pump ground drive device with a built-in braking device:

[0048] When the disc permanent magnet motor 3 drives the main shaft 22 and the sucker rod 10 to rotate in the forward direction, the roller 26 moves towards the wide end of the elongated hole under the action of centrifugal force and the inclined plane, and maintains sliding contact with the main shaft 22. The brake function is not activated, and the disc screw pump ground drive device is in normal oil production working state. The disc permanent magnet motor 3 drives the main shaft 22 and the sucker rod 10 to rotate in the forward direction. The roller 26 is mainly subjected to the centrifugal force generated by the rotation and the friction between the roller 26 and the surface of the main shaft 22 and the inclined plane of the elongated hole. The centrifugal force and friction drive the roller 26 to move along the inclined plane of the elongated hole towards the wide end of the elongated hole. The brake disc 25 is in a semi-disengaged state from the main shaft 22, and the brake device does not produce a braking effect.

[0049] The braking device 4 adopts the principle of a one-way bearing. Through a clever wedge-shaped space design, the internal roller 26 can rotate freely in one direction and lock in the other, thereby realizing one-way power transmission or reverse braking. When the disc permanent magnet motor 3 stops or needs to be braked, under the friction and elastic pressure of the O-ring 27, the roller 26 moves to the narrow end of the elongated hole. At this time, the roller 26 wedges between the outer surface of the main shaft 22 and the inner wall of the narrow end of the elongated hole, locking the main shaft 22 to the brake disc 25. The brake disc 25 and the bearing housing 5 damping grease slow down the reverse rotation speed. At the instant the rotation speed drops sharply, the centrifugal force on the roller 26 rapidly weakens and disappears. Friction is generated between the roller 26 and the surface of the decelerating spindle 22, and the direction of this friction is opposite to the reverse rotation trend. Simultaneously, the elastic contraction force of the O-ring 27 continuously presses all the rollers 26 towards the center. Under the combined action of this friction and pressing force, the rollers 26 are forcibly pushed from the wide end of the elongated hole to the narrow end. The slight reverse motion of roller 26 causes the roller 26 to be quickly and firmly wedged between the outer cylindrical surface of the rotating main shaft 22 and the inclined inner wall of the narrow end of the elongated hole, thereby instantly and rigidly locking the main shaft 22 and the brake disc 25. When the main shaft 22 and the brake disc 25 are locked, the reverse torque of the main shaft 22 is transmitted to the entire brake disc 25 through the roller 26. The conical surface of the outer contour of the brake disc 25 moves relative to the corresponding conical surface at the top of the inner wall of the bearing housing 5. The high-viscosity damping grease filled between these two conical surfaces plays a role. When subjected to strong shear, the damping grease generates huge viscous resistance. This resistance is converted into a continuous and stable braking torque, which acts on the locked brake disc 25, thereby effectively counteracting the reverse rotational energy. The reverse motion of the sucker rod 10 is transformed into a slow and controllable deceleration process until it stops, preventing safety accidents caused by the high-speed reverse rotation of the sucker rod 10, avoiding the mechanical parts from bearing huge impact loads, and eliminating the need for close manual intervention, which greatly improves the safety and reliability of the equipment.

[0050] The specific embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Many modifications and variations can be made based on the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A ground drive device for a disc screw pump with a built-in braking device, characterized in that: The system includes a square clamp (1), a disc permanent magnet motor (3), a braking device (4), a bearing housing (5), and a sucker rod (10). The disc permanent magnet motor (3) includes a main shaft (22), which is located at the central axis of the disc permanent magnet motor (3). The main shaft (22) is sleeved on the outside of the sucker rod (10), and the top of the main shaft (22) is connected to the top of the sucker rod (10) through the square clamp (1). The braking device (4) includes a brake disc (25), rollers (26), and an O-ring (27). The brake disc (25) is coaxially sleeved on the main shaft (22). The inner wall of the brake disc (25) has multiple elongated holes along the circumferential direction for placing rollers (26). The width of the elongated holes gradually decreases along the reverse direction of the main shaft. The O-ring (27) is embedded in the brake disc (25). The inner sidewall of the O-ring (27) contacts the surface of the roller (26). The outer contour of the brake disc (25) is a conical surface. The bearing housing (5) is located below the disc permanent magnet motor (3). The top of the inner wall of the bearing housing (5) is provided with a conical surface that matches the outer contour of the brake disc (25). The brake disc (25) is supported on the inner wall of the bearing housing (5) by the conical surface of its outer contour. On the top conical surface, the contact surface between the brake disc (25) and the bearing housing (5) is filled with damping grease; a sealing sleeve (2) is fitted on the outside of the sucker rod (10), and a square seat is provided on the top of the sealing sleeve (2). A first groove is provided on the top of the main shaft (22), and the main shaft (22) is fitted onto the outside of the sealing sleeve (2). The sealing sleeve (2) is engaged with the first groove through the square seat. A second groove is provided at the bottom of the square clip (1), and the square clip (1) is engaged with the square seat through the second groove. There are two square clips (1), and the two square clips (1) are connected by bolts. After connection, lock the sucker rod (10); the sealing sleeve (2) includes a lock nut (12), a packing gasket (13), a central tube (14), a PTFE oil seal (15) and a gland (16). The central tube (14) has grooves at the top and bottom respectively. The packing gasket (13) is set in the groove at the top of the central tube (14). The packing gasket (13) is fixed by the lock nut (12). The PTFE oil seal (15) is set in the groove at the bottom of the central tube (14). The PTFE oil seal (15) is fixed by the gland (16). The bottom of the sealing sleeve (2) is provided with a lower sealing assembly (8).

2. The disc screw pump ground drive device with built-in braking device according to claim 1, characterized in that: The braking device (4) also includes an upper cover (24) and a lower cover (28), which are connected to the upper and lower sides of the brake disc (25) by screws (23).

3. The disc screw pump ground drive device with built-in braking device according to claim 1, characterized in that: The lower sealing assembly (8) includes a wear-resistant seat (29), a fastening seat (30), and a mounting seat (32). The top of the wear-resistant seat (29) is connected to the central tube (14), and the bottom is provided with the mounting seat (32). The mounting seat (32) and the wear-resistant seat (29) are connected by the fastening seat (30). An elastic pad (31) is provided at the connection between the wear-resistant seat (29) and the fastening seat (30). A well sealer (9) is provided at the bottom of the mounting seat (32).

4. The disc screw pump ground drive device with built-in braking device according to claim 3, characterized in that: The fastening seat (30) is an annular structure with an internal thread on the inner side, and the mounting seat (32) has an external thread on its outer surface. The fastening seat (30) and the mounting seat (32) are connected by threads.

5. A disc screw pump ground drive device with a built-in braking device according to claim 1, characterized in that: The disc-type permanent magnet motor (3) also includes a housing, a rotor (19) and a stator (20). The rotor (19) and the stator (20) are both located inside the housing. The rotor (19) is sleeved on the outside of the main shaft (22). The stator (20) is sleeved on the outside of the rotor (19). The outside of the stator (20) is connected to the inner wall of the housing. The housing includes an upper end cover (17), an outer shell (18) and a lower end cover (21). The upper end cover (17) and the lower end cover (21) are respectively connected to the upper and lower surfaces of the outer shell (18) by bolts.

6. A disc screw pump ground drive device with a built-in braking device according to claim 5, characterized in that: The disc-type permanent magnet motor (3) is provided with a junction box (11), which is fixed to the outer shell (18) by bolts.

7. The disc screw pump ground drive device with built-in braking device according to claim 1, characterized in that: The main shaft (22) is a stepped shaft. A deep groove ball bearing (6) and a thrust self-aligning bearing (7) are installed in the bearing housing (5). The outer rings of the deep groove ball bearing (6) and the thrust self-aligning bearing (7) are in contact with the inner wall of the bearing housing (5), and the inner rings are in contact with the outer wall of the main shaft (22). The deep groove ball bearing (6) and the thrust self-aligning bearing (7) are fixed by the steps of the main shaft (22).

8. A braking method for a disc screw pump ground drive device with a built-in braking device as described in any one of claims 1-7, characterized in that: When the disc permanent magnet motor (3) stops or needs to be braked, under the friction and elastic pressure of the O-ring (27), the roller (26) moves to the narrow end of the elongated hole. At this time, the roller (26) wedges into the outer surface of the main shaft (22) and the inner wall of the narrow end of the elongated hole, locking the main shaft (22) and the brake disc (25), and slowing down the reverse speed through the damping grease between the brake disc (25) and the bearing box (5), thereby preventing the sucker rod (10) from reversing.

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