Screw pump with single motor

Abstract

A single-motor screw pump comprises a second sleeve serving as a supporting assembly; the rotary adjusting assembly is arranged in the second sleeve and structurally comprises an adjusting sleeve; the motor is fixed at the upper end of the adjusting sleeve and provides driving acting force for positive and negative rotation; the lower end of the adjusting core shaft extends downwards and is connected with the rotor assembly, and a plurality of groups of bulge structures and chute structures which are matched with each other are arranged between the adjusting sleeve and the adjusting core shaft; the number of the skewed slot structures is two, the skewed slot structures are symmetrically arranged along the axis of the adjusting mandrel, and the protruding structures intermittently slide in the two skewed slots along with forward and reverse rotation of the motor and are used for supporting the adjusting mandrel and driving the adjusting mandrel to axially move and synchronously rotate. The screw pump is compact and reasonable in structure and convenient to operate, the overall structure of the screw pump is greatly simplified through the design that a sucker rod is omitted, the fit clearance of the stator and rotor assembly can be optimized through forward rotation and reverse rotation of the motor, the reverse rotation is used for unfreezing and sand discharging, and the adaptability and reliability of the pump are enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of screw pumps, in particular to a screw pump with a single motor. Background Art

[0002] In the existing field of oil extraction technology, screw pumps are widely used. After a period of operation, the gap between the stator and rotor of a conventional linear screw pump increases due to wear, resulting in poor sealing of the stator and rotor cavity, which greatly reduces the pump efficiency. The emergence of conical screw pumps can effectively solve this problem. In conical screw pumps, both the stator and the rotor have a certain taper. In actual use, the gap between the stator and the rotor can be effectively adjusted by simply controlling the rotor to lift or lower.

[0003] However, when a screw pump is used to extract oil from deep wells, the sucker rod connected to its rotor is usually 1500-2500 meters long. During the oil extraction process, the sucker rod will be stretched or even unstable due to its own gravity and the crude oil mixture, which greatly affects the stability of the screw pump. Therefore, it is very important to design a rotation adjustment component that can accurately control the rotor height to adjust the gap between the stator and rotor of the screw pump.

[0004] The existing screw pumps still have the following problems:

[0005] 1. The patent with publication number CN118128748A discloses an adjustable submersible screw pump, in which the rotation adjustment component of the screw pump uses a threaded connection, which can adjust the up and down movement of the sucker rod while limiting the sucker rod. The biggest disadvantage of the threaded connection is that the corresponding function can only be realized when the motor rotates forward, and it is very likely to be disengaged when the motor rotates reversely. The motor reversal may exist in the following two situations: (1) After each shutdown of the screw pump, due to the presence of a large amount of crude oil mixture in the pumping pipe downhole, the crude oil mixture will squeeze the rotor and flow out of the stator and rotor cavity under the action of gravity. At this time, the rotor is in a reverse state and will drive the sucker rod and the motor core shaft to reverse together. (2) When there is a lot of sand and gravel in the stator and rotor cavity, the stator and rotor may be stuck and cannot operate normally. At this time, the gap between the stator and rotor can be increased by reversing the motor and lifting the rotor, thereby achieving unblocking and sand removal.

[0006] 2. The existing rotation adjustment assembly is usually used to limit the sucker rod, so it needs to bear the weight of the sucker rod. The sucker rod is made of metal. The sucker rod in a deep well can reach several tons. Even if there is a certain pulling force on the sucker rod on the well, the rotation adjustment assembly will still be under great pressure under the action of the sucker rod and the crude oil mixture. Therefore, low-delay adjustment cannot be achieved; the lifting stroke is easily affected by the elasticity of the sucker rod. The use of a screw pump without a sucker rod can avoid this problem. The screw pump without a sucker rod includes a motor 1 for driving the rotor to rotate and a motor 2 for lifting the rotor. Since the screw pump is located in the oil pipe, the motor 1, the motor 2, the conical stator and rotor structure, the torque anchor, the tail pipe and other structures must be connected in series, so at least one motor is a hollow motor. In actual scenarios, it is difficult to use a hollow motor suitable for oil field wells. The positive and negative wires of the hollow motor are not ordinary wires. Since it is located underground, vertical tension, temperature, shell protection, etc. need to be considered during design. On the other hand, the certification of hollow motors is complicated and usually takes 1-2 years to certify. Therefore, this solution is not applicable to the current oil field background.

[0007] For this purpose, we propose a single-motor screw pump. Summary of the invention

[0008] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a single-motor screw pump, which greatly simplifies the overall structure of the screw pump by omitting the design of the sucker rod. Through the forward and reverse rotation of the motor, the forward rotation can optimize the fitting clearance of the stator and rotor assemblies, while the reverse rotation is used to release sand, thereby enhancing the adaptability and reliability of the pump.

[0009] The technical solution adopted by the present invention is as follows:

[0010] A single-motor screw pump, comprising:

[0011] A second casing, which is used to support the structure inside it;

[0012] A rotation adjustment assembly is placed in the second sleeve, and its structure includes an adjustment sleeve;

[0013] A motor is fixed to the upper end of the adjusting sleeve and provides a driving force for forward and reverse rotation;

[0014] The lower end of the adjusting mandrel extends downward and is connected to the rotor assembly, and a plurality of groups of mutually matching protrusion structures and inclined groove structures are arranged between the adjusting sleeve and the adjusting mandrel;

[0015] There are two inclined groove structures, which are symmetrically arranged along the axis of the adjustment core shaft. The protruding structure slides intermittently in the two inclined grooves as the motor rotates forward and reverse, so as to support the adjustment core shaft and drive the axial displacement and synchronous rotation of the adjustment core shaft.

[0016] Furthermore, a protrusion structure or an inclined groove structure is provided on the adjustment core shaft, and a corresponding inclined groove structure or a protrusion structure is provided on the adjustment sleeve, and when the inclined groove structure is located on the adjustment core shaft, the two inclined groove structures are arranged in an "eight" shape, and when the inclined groove structure is located on the adjustment sleeve, the two inclined grooves are arranged in an inverted "eight" shape, and the two inclined grooves are respectively a forward rotation groove and a reverse rotation groove, and the vertical height of the forward rotation groove is ≤ the vertical height of the reverse rotation groove, so that the axial displacement of the adjustment core shaft when it is reversed is greater than the axial displacement of the adjustment core shaft when it is forwardly rotated.

[0017] Furthermore, the protrusion structures are balls, each group of protrusion structures includes a ball, and the balls are intermittently rollingly connected in the corresponding two inclined groove structures.

[0018] Furthermore, an annular groove is provided at the lower end of the outer wall of the adjustment sleeve, at least one through hole group is provided on the annular groove, and the ball is arranged in the through hole group, each through hole group includes two symmetrical through holes, and the annular groove extends to the lower edge of the adjustment sleeve, and a first sleeve is provided on the outer side of the annular groove to prevent the ball from rolling outward.

[0019] Furthermore, the inclined groove structure includes a straight groove, a forward rotation groove and a reverse rotation groove. The forward rotation groove and the reverse rotation groove are connected in an "eight" shape on both sides of the axially arranged straight groove. The forward rotation groove is a gentle inclined groove, and an inflection point segment is provided in the middle position of the reverse rotation groove. The front and rear segments of the inflection point segment are both inclined sides in the same direction, and the inclined sides of the inflection point segment are in opposite directions.

[0020] Furthermore, the protruding structure is a fixedly arranged oblique tooth, and the number of oblique teeth in each group of protruding structures is two and they are in an upright or inverted "eight" shape, a gap is provided between the two oblique teeth, and the two oblique teeth have the same slope as the oblique groove on the same side.

[0021] Furthermore, it also includes an eccentric rod, which is arranged between the adjustment mandrel and the rotor assembly, and the eccentric rod is connected to the lower end of the adjustment mandrel through a connecting portion;

[0022] The connecting part includes a fixing sleeve, a fourth sleeve and an elastic retaining ring for the shaft, and the fixing sleeve is tightly connected to the adjusting mandrel and the eccentric rod through a spline and a radial tooth groove structure respectively, ensuring that it can remain stable during forward and reverse rotation.

[0023] Furthermore, a spring is also included, which is designed on the eccentric rod and is used to provide sufficient lifting force for the rotor assembly in specific environments such as horizontal wells, thereby ensuring good contact and sealing between the stator and rotor assemblies.

[0024] Furthermore, an annular protrusion is provided at the lower end of the inner wall of the second sleeve, and a bearing group is provided at the upper end of the annular protrusion. The inner wall and outer wall of the bearing group are respectively connected to the second sleeve and the adjustment core shaft, which has a stabilizing and load-bearing effect on the adjustment core shaft.

[0025] Furthermore, the lower end of the annular protrusion is connected to a straightening and sealing mechanism, the structure of which includes a bearing washer, a cylindrical roller bearing, a packing and a gasket. The cylindrical roller bearing is fixedly sleeved on the adjustment mandrel for straightening the adjustment mandrel and isolating the solid-liquid mixture.

[0026] The beneficial effects of the present invention are as follows:

[0027] The present invention has a compact and reasonable structure and is easy to operate. By eliminating the design of the sucker rod, the overall structure of the screw pump is greatly simplified. Through the forward and reverse rotation of the motor, the forward rotation drives the coordination of the protrusion structure and the inclined groove structure to optimize the coordination clearance of the stator and rotor assemblies, while the reverse rotation is used to release the jam and discharge the sand, thereby enhancing the adaptability and reliability of the pump. The spring designed on the eccentric rod enables the pump to adapt to different well conditions, especially to ensure the fit between the rotor assembly and the stator in horizontal wells. The load-bearing capacity of the rotating adjustment assembly is improved, ensuring the stable operation of the pump when subjected to large axial forces. In summary, the screw pump of this embodiment achieves a comprehensive improvement in cost, efficiency, adaptability and stability through a series of innovative designs.

[0028] At the same time, the present invention also has the following advantages:

[0029] Cost saving and simplified structure: The design without sucker rod not only saves material cost, but also eliminates the hollow motor used in oil fields, thus greatly simplifying the structure of the screw pump.

[0030] Reduce the difficulty of well installation: The sucker rod-free design significantly reduces the difficulty of well installation of the screw pump, which is especially suitable for complex well conditions such as deep wells, heavy oil wells, horizontal wells, etc., and maintains efficient operation.

[0031] Improve pumping efficiency and oil extraction efficiency: By increasing the maximum speed of the motor to 3000 rpm (traditional screw pumps are usually 50-400 rpm), this screw pump significantly improves pumping efficiency and oil extraction efficiency. Thanks to the sucker rod-free design, the influence of friction on the life of the oil pipe is avoided.

[0032] Enhanced adaptability and reliability: The screw pump supports forward and reverse rotation of the motor. Forward rotation is used to lift the rotor assembly and optimize the clearance between the stator and rotor assemblies, while reverse rotation is used to remove jams and discharge sand, ensuring the normal operation of the motor, thereby improving the adaptability and reliability of the screw pump.

[0033] Stable connection design: The spline and radial tooth structure are used to avoid the shortcomings of traditional threaded connections that are easy to disengage and damage, ensuring that the screw pump can be firmly connected in both forward and reverse rotations.

[0034] Adapt to different well conditions: The spring designed on the eccentric rod enables the screw pump to adapt to the needs of different well conditions, especially in horizontal wells, ensuring that the rotor assembly fits the stator and ensures normal operation.

[0035] Improve the load-bearing capacity of the rotating adjustment component: The specially designed bearing group assembly method converts the axial force on the rotating adjustment component into radial force, thereby improving the load-bearing capacity of the rotating adjustment component and ensuring that the screw pump can maintain stable operation when subjected to large axial forces.

[0036] Intelligent gap adjustment and jam-release mechanism: By rotating the inclined slot structure design of the adjustment component, the gap between the stator and rotor components can be automatically adjusted when the motor rotates. At the same time, when the gap between the stator and rotor components increases or the oil outlet pressure decreases, the motor speed can be increased to maintain a stable oil output. In addition, the jam-release and sand discharge function can be realized when the motor is reversed. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the three-dimensional structure of the screw pump in the present invention.

[0038] Figure 2 It is the front view of the screw pump in the present invention.

[0039] Figure 3 for Figure 2 Cross-sectional view of section AA.

[0040] Figure 4 It is a partially enlarged schematic diagram of the adjustment of the cooperation between the core shaft and the ball in the present invention.

[0041] Figure 5 This is a structural diagram of the inclined groove structure on the adjustment core shaft in the present invention.

[0042] Figure 6 It is a schematic diagram of the assembly of the bearing group in the present invention.

[0043] Figure 7 It is a schematic diagram of the assembly of the righting and sealing mechanism in the present invention.

[0044] Figure 8 It is a schematic diagram of the connection between the adjustment core shaft and the eccentric rod in the present invention.

[0045] Fig. 9 It is a schematic diagram of the connection between the helical teeth and the helical groove structure in the second embodiment of the present invention.

[0046] in:

[0047] 1. Oil pipe fittings; 101. First oil pipe; 102. Second oil pipe; 103. Connector; 2. Motor; 3. Washer; 4. Rotation adjustment assembly; 401. Motor flange; 402. Adjustment sleeve; 403. Ball; 403', helical gear; 404. First sleeve; 405. Threaded sleeve; 406. Extension sleeve; 5. Adjustment mandrel; 501. Bevel groove structure; 5011. Straight groove; 5012. Forward rotation groove; 5013. Reverse rotation groove; 5 0131, inflection point section; 6, rotating sleeve; 7, bearing assembly; 8, second sleeve; 9, straightening seal mechanism; 901, bearing washer; 902, cylindrical roller bearing; 903, packing; 904, gasket; 905, isolation ring; 10, first flange; 11, third sleeve; 12, second flange; 13, eccentric rod; 14, spring; 15, connecting part; 1501, fixed sleeve; 1502, fourth sleeve; 1503, elastic retaining ring for shaft. DETAILED DESCRIPTION

[0048] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0049] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0050] As described in the background art, during the oil production process, the sucker rod will be stretched or even unstable and jump due to its own gravity and the crude oil mixture, which greatly affects the stability of the screw pump operation.

[0051] Traditional screw pumps usually rely on sucker rods to achieve the rotation and axial movement of the rotor assembly, but this method has many disadvantages, such as high material cost, difficulty in well installation, and influence by the elasticity of the sucker rod. In order to overcome these disadvantages, the present application designs a single-motor screw pump, which realizes the rotation control and lifting control of the rotor assembly by a single motor through the series structure of motor-rotation adjustment assembly-eccentric rod-stator and rotor assembly.

[0052] See also Figure 1-Figure 8 As shown,

[0053] According to some embodiments of the present application, a single-motor screw pump is provided, the structure of which includes an oil pipe 1, a motor 2, a second sleeve 8, a rotation adjustment assembly 4, an adjustment core shaft 5, an eccentric rod 13, a rotor assembly and other components.

[0054] like Figure 3As shown, in this embodiment, the oil pipe member 1 is composed of a first oil pipe 101, a second oil pipe 102 and a connector 103. This segmented design facilitates installation, disassembly and maintenance, while enhancing the adaptability and flexibility of the oil pipe member, and can meet the pumping requirements of different lengths. It is easy to maintain and enhances adaptability.

[0055] The second sleeve 8 in this embodiment is arranged inside the oil pipe member 1. The second sleeve 8 provides support for the rotation adjustment component 4. The second sleeve 8 in this embodiment is fixed to the oil pipe member 1 through a connecting member, so as to achieve a better supporting effect. At the same time, the lower end of the second sleeve 8 is connected to the third sleeve 11 through the first flange 10, and then a cylindrical cavity is formed inside the second sleeve 8 and the third sleeve 11.

[0056] like Figure 3 and Figure 4 As shown, the rotation adjustment assembly 4 in this embodiment is placed in the second sleeve 8, and its structure mainly includes an adjustment sleeve 402, which can provide a support effect for the adjustment mandrel 5, and can also drive the adjustment mandrel 5 to rotate synchronously and move axially;

[0057] The motor 2 is fixed to the upper end of the rotating adjustment component 4 and provides a driving force for forward and reverse rotation. The motor 2 in this embodiment is fixedly connected to the motor flange 401 through the gasket 3, and the motor flange 401 is further fixedly connected to the adjustment sleeve 402. In this embodiment, by adopting a forward and reverse motor 2, the screw pump can be driven, and the gap between the stator and rotor components can be controlled to achieve the effect of unblocking.

[0058] like Figure 3 and 4 As shown, the lower end of the adjusting core shaft 5 in this embodiment extends downward and is connected to the rotor assembly, and a plurality of groups of mutually matching protrusion structures and inclined groove structures 501 are arranged between the adjusting sleeve 402 and the adjusting core shaft 5; the number of inclined groove structures 501 is two and they are symmetrically arranged along the axis of the adjusting core shaft 5, and the protrusion structure intermittently slides in the two inclined grooves with the forward and reverse rotation of the motor 2, so as to support the adjusting core shaft 5 and drive the adjusting core shaft 5 to axially displace and synchronously rotate.

[0059] The adjusting core shaft 5 is provided with a protruding structure or an inclined groove structure 501 , and the adjusting sleeve 402 is provided with a corresponding inclined groove structure 501 or a protruding structure.

[0060] In this embodiment, Figure 3 and Figure 4As shown, an inclined groove structure 501 is provided on the adjusting core shaft 5, and a protrusion structure is provided on the adjusting sleeve 402, and when the inclined groove structure 501 is located on the adjusting core shaft 5, the two inclined groove structures 501 are arranged in an "eight" shape, and when the inclined groove structure 501 is located on the adjusting sleeve 402, the two inclined grooves are arranged in an inverted "eight" shape, and the two inclined grooves are respectively a forward rotation groove 5012 and a reverse rotation groove 5013, and the vertical height of the forward rotation groove 5012 is ≤ the vertical height of the reverse rotation groove 5013, so that the axial displacement of the adjusting core shaft 5 when reversing is greater than or equal to the axial displacement of the adjusting core shaft 5 when rotating forward, and this groove structure design realizes precise axial control and rotation transmission, so that the adjusting core shaft 5 can maintain stable transmission performance during forward and reverse rotation, thereby improving the working efficiency and stability of the pump.

[0061] In another embodiment, a protrusion structure is provided on the adjusting core shaft 5 , and an inclined groove structure is provided on the adjusting sleeve 402 .

[0062] In this embodiment, Figure 3 As shown, the eccentric rod 13 is fixedly connected to the lower end of the adjusting core shaft 5 , and the rotor assembly is fixedly connected to the lower end of the eccentric rod 13 .

[0063] The eccentric rod 13 is made of high-strength alloy material and is tightly connected to the lower end of the adjustment mandrel 5 by spline and radial tooth structure, ensuring that it can remain stable during forward and reverse rotation to avoid the risk of tripping. The rotor assembly is fixedly connected to the lower end of the eccentric rod 13 through a special process to form a whole, ensuring the stability of rotation and transmission efficiency.

[0064] At the lower end of the rotation adjustment component 4, the first flange 10, the third sleeve 11, and the second flange 12 are connected in sequence to form a sealed and stable support structure. The design of the connection part 15 is particularly ingenious, the fixed sleeve 1501 is tightly wrapped inside the fourth sleeve 1502, and the axial limit is achieved through the shaft elastic retaining ring 1503, which not only ensures the flexibility of the connection, but also ensures the overall stability.

[0065] The lower end of the adjustment mandrel 5 is fixedly connected to the annular groove at the upper end of the eccentric rod 13 through the connecting portion 15. Figure 8 As shown, there are two types of fixing methods:

[0066] In the first fixing method, the outer wall of the connection between the adjustment core shaft 5 and the eccentric rod 13 is provided with a plurality of radial tooth grooves, and the inner sides of the two semi-cylindrical shells of the fixed sleeve 1501 have corresponding matching radial tooth grooves, and the adjustment core shaft 5 and the eccentric rod 13 are relatively fixed in the axial direction after radial fitting. A step groove with a smaller outer diameter is provided at the upper end of the outer wall of the fixed sleeve 1501, and the fourth sleeve 1502 is sleeved on the step groove of the fixed sleeve 1501 to constrain the fixed sleeve 1501 in the radial direction. The shaft elastic retaining ring 1503 is embedded in the groove on the outer wall of the annular groove of the fixed sleeve 1501 to prevent the fourth sleeve 1502 from sliding axially relative to the fixed sleeve 1501.

[0067] In the second fixing method, the lower end of the adjustment mandrel and the annular groove at the upper end of the eccentric rod 13 are splined to limit the relative rotation of the two in the radial direction. Similarly, the fixing method of the lower end of the eccentric rod 13 and the screw pump rotor assembly is similar to the above method and will not be repeated here.

[0068] The upper end of the first flange 10 is provided with an annular groove with a smaller outer diameter, and the lower end is provided with an annular groove hole. The second sleeve 8 is sleeved on the annular groove at the upper end of the first flange 10. The upper end of the third sleeve 11 is embedded in the annular groove hole of the first flange 10, and the lower end is sleeved on the annular groove of the second flange 12.

[0069] The eccentric rod 13 includes a straight rod and annular grooves at both ends with a diameter larger than the diameter of the straight rod. The second flange 12 and the spring 14 are both sleeved on the straight rod portion of the eccentric rod 13, and the upper end of the spring 14 is restricted under the end surface of the annular groove hole of the second flange 12, and the lower end of the spring 14 is restricted on the annular groove surface at the lower end of the eccentric rod.

[0070] In another embodiment, in order to assemble the second flange 12 and the spring 14 onto the eccentric rod, a plug-in connection method can be actually adopted, where the second flange 12 and the spring 14 are first assembled onto a section of the eccentric rod, and then the two sections of the eccentric rod are plugged in.

[0071] Specifically, the oil pipe member 1 serves as a supporting structure of the entire system, and is composed of a first oil pipe 101 , a second oil pipe 102 and a connecting member 103 .

[0072] In this embodiment, during the operation of the screw pump, the clearance between the stator and rotor assemblies can be determined by detecting the oil outlet pressure value. When it is detected that the clearance between the stator and rotor assemblies increases, that is, the oil outlet pressure decreases, the oil outlet pressure can be increased by increasing the speed of the motor 2 to keep the oil output stable. This method can achieve real-time adjustment of the pump efficiency and improve the efficiency of oil extraction.

[0073] In this embodiment, in order to prevent the various components of the screw pump from being disengaged when the motor 2 is reversed, the present application does not use the traditional threaded connection method when connecting the adjustment mandrel 5, the eccentric rod 13 and the rotor assembly, but creatively combines the spline and radial tooth groove structure. This connection method allows the screw pump to be firmly connected regardless of forward or reverse rotation, ensuring the stability of the screw pump operation.

[0074] In this embodiment, in a horizontal well, since the rotor assembly cannot sink axially due to its own weight, the present application designs a spring 14 on the eccentric rod 13. With the thrust of the spring 14, the rotor assembly can be fitted with the stator. When the motor 2 is started, the rotor assembly is lifted up again so that the gap between the stator and rotor assembly reaches the set value. This design ensures the adaptability of the screw pump under different well conditions.

[0075] like Figure 3 and Figure 6 As shown, the lower end of the inner wall of the second sleeve 8 in this embodiment is provided with an annular protrusion, and the upper end of the annular protrusion is provided with a bearing group 7, which includes a plurality of stacked bearing groups, and the inner wall and the upper end of the bearing group 7 are connected with a rotating sleeve 6, and the rotating sleeve 6 is sleeved on the adjustment mandrel 5; the bearing group 7 is mainly used to prevent the second sleeve 8 from rotating with the rotating sleeve 6 and causing equipment damage. In actual use, the bearing group 7 will also be subjected to axial pressure. In order to ensure that the bearing group 7 can work normally, the present application adopts a special design during assembly: the rotating sleeve 6 only contacts the inner ring of the bearing group 7, not the outer ring; and the second sleeve 8 only contacts the outer ring of the bearing group 7, not the inner ring. Under this assembly, the bearing group 7 can convert the axial force it receives into a radial force, thereby improving the load-bearing capacity of the adjustment mandrel 5, that is, improving the load-bearing capacity of the rotor assembly.

[0076] The lower end of the annular protrusion is provided with a centering seal mechanism 9, which mainly includes a bearing washer 901, a cylindrical roller bearing 902, a packing 903 and a gasket 904. The cylindrical roller bearing 902 is mainly used to center the adjustment mandrel 5. The cylindrical roller bearing 902 is fixedly sleeved on the adjustment mandrel 5 to reduce the influence of the radial movement of the eccentric rod 13 on the adjustment mandrel 5 and avoid damage to the rotating adjustment component 4. The packing 903, the gasket 904 and the isolation ring 905 are placed alternately to isolate solid-liquid mixtures such as petroleum and sand and gravel to prevent the solid-liquid mixture from entering the bearing group 7 and the cylindrical roller bearing 902 and causing equipment damage.

[0077] The oil pipe fitting 1 in this embodiment serves as a supporting structure for the entire system, and its design is also crucial. The oil pipe fitting 1 of the present application includes a first oil pipe 101, a second oil pipe 102, and a connector 103 connecting the two oil pipes. The connector 103 is provided with a plurality of axial oil holes for passing oil. At the same time, the connector 103 is also used to limit the radial displacement of the eccentric rod 13 and protect the connection between the adjustment core shaft 5 and the eccentric rod 13 from damage. This design improves the stability and reliability of the entire system. In addition, a first flange 10, a third sleeve 11, a second flange 12, and a connecting portion 15 are provided. The connecting portion 15 includes a fixing sleeve 1501, a fourth sleeve 1502, and an elastic retaining ring 1503 for the shaft, which are used to further stabilize and connect the various components.

[0078] Embodiment 1

[0079] In this embodiment, the protruding structures are balls 403 , each group of protruding structures includes a ball 403 , and the balls 403 are intermittently rollingly connected in the corresponding two inclined groove structures 501 .

[0080] In this embodiment, the ball 403 is disposed on the adjustment sleeve 402 as an example for description. In actual use, the ball 403 may also be disposed on the adjustment core shaft 5 .

[0081] The lower end of the outer wall of the adjustment sleeve 402 in this embodiment is provided with an annular groove, and at least one through hole group is provided on the annular groove, and the ball 403 is arranged in the through hole group, each through hole group includes two symmetrical through holes, and the annular groove extends to the lower edge of the adjustment sleeve 402, and the outer side of the annular groove is provided with a first sleeve 404 to prevent the ball 403 from rolling outward.

[0082] In this embodiment, three through hole groups are arranged on the annular groove, and each through hole group includes two symmetrical through holes.

[0083] The annular groove in this embodiment extends to the lower edge of the adjustment sleeve 402 to facilitate the subsequent docking of the first sleeve 404 .

[0084] At the same time, a first sleeve 404 is sleeved on the annular groove, and the first sleeve 404 is sleeved on the outside of the annular groove to prevent the ball 403 from rolling outward; the threaded sleeve 405 is threadedly connected to the annular groove, and the upper and lower ends of the threaded sleeve 405 are respectively fixed to the first sleeve 404 and the extension sleeve 406 by welding. The design of the ball 403 reduces friction and improves the rotation flexibility of the adjustment sleeve 402; the coordinated use of the first sleeve 404 and the threaded sleeve 405 ensures the stability and sealing of the entire structure and prevents the intrusion of external impurities.

[0085] The lower end of the extension sleeve 406 cooperates with the rotating sleeve 6 through an annular groove. The lower end of the rotating sleeve 6 is an annular groove with a smaller outer diameter. The bearing group 7 is sleeved on the outside of the annular groove of the rotating sleeve 6, and the bearing group 7 is engaged in the annular groove hole of the second sleeve 8.

[0086] The upper end of the adjustment mandrel 5 is provided with a plurality of parallel inclined groove structures 501, each of which includes at least one inclined groove structure 501, each of which includes a straight groove 5011, and a forward rotation groove 5012 and a reverse rotation groove 5013 on both sides of the straight groove 5011, respectively, the forward rotation groove 5012 and the reverse rotation groove 5013 are arranged on both sides of the straight groove 5011 in an "eight-shaped" shape, and the forward rotation groove 5012 and the reverse rotation groove 5013 are both connected to the straight groove 5011, so as to facilitate the movement of the ball 403. Moreover, the straight grooves 5011 in the plurality of inclined groove structures 501 are located on the same vertical line and are connected to each other.

[0087] In this embodiment, the number of inclined groove structures 501 in the same group is two and they are symmetrically distributed, and are arranged corresponding to the ball 403, so that the ball 403 can move in the straight groove 5011, the forward rotation groove 5012 and the reverse rotation groove 5013 of the inclined groove structure 501. When the motor 2 drives the adjustment sleeve 402 to rotate, the ball 403 will move to the forward rotation groove 5012 or the reverse rotation groove 5013, thereby contacting the other end of the forward rotation groove 5012 or the reverse rotation groove 5013, thereby driving the adjustment core shaft 5 to move together, and at the same time, the rotor assembly is driven to rotate through the eccentric rod 13, thereby achieving the effect of driving and unblocking and sand removal.

[0088] At the same time, in this embodiment, Figure 4 As shown, the vertical height h1 of the forward rotation groove 5012 is ≤ the vertical height h2 of the reverse rotation groove 5013, that is, when reverse rotation is performed, since the vertical height h2 of the reverse rotation groove 5013 is higher, the gap between the stator and rotor assemblies can be increased, thereby improving the sand removal effect.

[0089] The positive rotation groove 5012 is a gently inclined groove, and the reverse rotation groove 5013 is provided with an inflection point section in the middle. The front and rear sections of the inflection point section are both inclined in the same direction, while the inclined sides of the inflection point section are in opposite directions. When the reverse rotation occurs, the rotor assembly can generate axial vibration, so that the adhered oil and sand and gravel are dispersed, making it easier to discharge sand.

[0090] The oil pipe 1, the motor 2 and its connection structure, the adjustment sleeve 402 and its accessories, the adjustment mandrel 5 and other components in this embodiment together constitute an efficient and stable screw pump system. Through the segmented design, the use of gaskets, the friction reduction design of the ball 403 and the precise chute structure 501 design, not only the problems existing in the traditional screw pump are solved, but also the pump efficiency is significantly improved, the cost is reduced, and the adaptability and reliability of the equipment are enhanced, so that the whole system has the advantages of easy maintenance, protection of the motor, stable sealing, improved flexibility and precise control, thereby improving the working efficiency and stability of the pump and meeting the needs of the oil extraction industry.

[0091] The specific working principle is as follows:

[0092] When the motor 2 is working, the motor shaft drives the motor flange 401 to rotate, and the adjustment sleeve 402, the first sleeve 404, the threaded sleeve 405, and the extension sleeve 406 fixed to the motor flange 401 all rotate synchronously. Since the operation of the motor 2 drives the adjustment sleeve 402 to rotate, the ball 403 on the adjustment sleeve 402 also rotates synchronously. The ball 403 embedded in the inclined groove structure 501 will roll from the straight groove 5011 into the forward rotation groove 5012 or the reverse rotation groove 5013, driving the adjustment shaft 5 to lift up. When the ball 403 reaches the end of the forward rotation groove 5012 or the reverse rotation groove 5013, the ball 403 and the adjustment shaft 5 are relatively fixed, and the two rotate synchronously.

[0093] (1) Forward rotation: When the motor 2 rotates forward, the ball 403 rolls from the straight groove 5011 into the forward rotation groove 5012, driving the adjustment mandrel 5 to lift up. As the adjustment mandrel 5 is lifted up, the eccentric rod 13 and the rotor assembly are also lifted up, so that the gap between the stator and rotor assemblies reaches the set gap. When the ball 403 reaches the end of the forward rotation groove 5012, the ball 403 and the adjustment mandrel 5 are relatively fixed, and the two rotate synchronously, and the screw pump starts to work normally.

[0094] (2) Reverse rotation to release the jam: When the cavity of the stator-rotor assembly is stuck by sand and gravel, the motor 2 can be controlled to reverse to release the jam. When the motor 2 reverses, the ball 403 rolls from the straight groove 5011 into the reverse rotation groove 5013, and also drives the adjustment mandrel 5 to lift up. Since the rotor assembly has the characteristics of positive rotation downward and reverse rotation upward, the rotor assembly will be lifted up during reverse rotation, thereby increasing the gap between the stator-rotor assembly and achieving sand release. At the same time, the effect of sand release is improved from three aspects: first, the rotor assembly is lifted up, increasing the gap between the stator-rotor assembly; second, due to the spiral structure of the stator-rotor assembly, the positive rotation is more inclined to squeeze the sand and gravel, while the reverse rotation is more likely to make the sand and gravel fall; third, the protrusion designed on the reverse rotation groove can vibrate the rotor assembly during reverse rotation, so that the adhered oil and sand and gravel are dispersed, making it easier to discharge sand.

[0095] (3) Stopping and restarting: When the motor 2 stops, the adjustment mandrel 5 connected to the rotor assembly will sink under the action of gravity due to the gap between the stator and rotor assemblies. At this time, the ball 403 is driven to roll back into the straight groove 5011 through the inclined rotation groove design to prepare for the next start. When the motor 2 is started again, the ball 403 will move in the upper row of inclined groove structure 501, causing the adjustment mandrel 5 to be lifted up first and then rotate synchronously.

[0096] Embodiment 2

[0097] like Fig. 9 As shown, in this embodiment, the protruding structure is a fixedly arranged beveled tooth 403', and the number of the beveled teeth 403' in each group of protruding structures is two and they are in an upright or inverted "eight" shape, corresponding to the positive rotation groove 5012 and the reverse rotation groove 5013 respectively. A gap is arranged between the two beveled teeth 403' to prevent interference with the movement of the beveled teeth 403' and influence on the axial movement distance, and the two beveled teeth 403' have the same slope as the beveled groove on the same side, so that the beveled teeth 403' and the beveled groove structure cooperate with each other.

[0098] like Fig. 9 As shown, the bevel teeth 403' can be set on the adjustment core shaft 5 or on the adjustment sleeve 402, and it can be clearly seen that when the bevel teeth 403' are located on the adjustment core shaft 5, the bevel groove structure 501 is an inverted "eight" shape; and when the bevel teeth 403' are located on the adjustment sleeve 402, the bevel groove structure 501 is an upright "eight" shape.

[0099] At the same time, in order to limit the position of the bevel teeth 403 ′, a limiting member is provided at the end of the bevel groove structure 501 to prevent the bevel teeth 403 ′ from excessive movement.

[0100] The specific working principle is the same as that of the first embodiment, that is, the helical teeth 403' cooperate with the bevel groove structure 501 to adjust the axial movement of the core shaft 5 by a certain distance, and can also perform forward and reverse rotation to achieve the effect of driving and unblocking.

[0101] In summary, the screw pump in this embodiment has shown many significant advantages in practical applications. First, by eliminating the design of the sucker rod, not only the material cost is effectively saved, but also the overall structure of the screw pump is greatly simplified, and the hollow motor used in the oil field is eliminated, which greatly reduces the difficulty of well installation, and is particularly suitable for complex well conditions such as deep wells, heavy oil wells, and horizontal wells. Secondly, the design without sucker rods avoids the friction caused by the long and non-linear arrangement of the sucker rods in the traditional rod pump, thereby allowing the motor speed to be increased to up to 3000 rpm, significantly improving the pump efficiency and oil production efficiency. In addition, the screw pump supports the forward and reverse rotation of the motor. The forward rotation can optimize the matching clearance of the stator and rotor assemblies, and the reverse rotation is used to unblock and discharge sand, which enhances the adaptability and reliability of the pump. In terms of connection, the spline and radial tooth groove structure are used instead of the traditional threaded connection to ensure the stable connection of the pump under forward and reverse rotation. At the same time, the spring designed on the eccentric rod enables the pump to adapt to different well conditions, especially in horizontal wells to ensure the fit between the rotor assembly and the stator. Finally, the specially designed bearing assembly method improves the load-bearing capacity of the rotating adjustment component and ensures the stable operation of the pump when subjected to large axial forces. In summary, the screw pump of this embodiment achieves comprehensive improvements in cost, efficiency, adaptability and stability through a series of innovative designs.

[0102] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A single motor screw pump, characterized in that: include: A second sleeve (8), which is used to support the structure inside it; A rotation adjustment component (4) is placed in the second sleeve (8), and its structure includes an adjustment sleeve (402); a motor (2) is fixed to the upper end of the rotation adjustment component (4) and provides a driving force for forward and reverse rotation; An adjusting mandrel (5), the lower end of which extends downward and is connected to the rotor assembly, and a plurality of groups of mutually matching protrusion structures and inclined groove structures (501) are arranged between the adjusting sleeve (402) and the adjusting mandrel (5); The number of the inclined groove structures (501) is two and they are symmetrically arranged along the axis of the adjustment core shaft (5); the protruding structure intermittently slides in the two inclined grooves as the motor (2) rotates forward and reverse, and is used to support the adjustment core shaft (5) and drive the adjustment core shaft (5) to axially displace and synchronously rotate.

2. A single-motor screw pump according to claim 1, characterized in that: The adjusting mandrel (5) is provided with a protruding structure or an inclined groove structure (501), and the adjusting sleeve (402) is provided with a corresponding inclined groove structure (501) or a protruding structure. When the inclined groove structure (501) is located on the adjusting mandrel (5), the two inclined groove structures (501) are arranged in an "eight" shape. When the inclined groove structure (501) is located on the adjusting sleeve (402), the two inclined grooves are arranged in an inverted "eight" shape. The two inclined grooves are respectively a forward rotation groove (5012) and a reverse rotation groove (5013). The vertical height of the forward rotation groove (5012) is less than or equal to the vertical height of the reverse rotation groove (5013), so that the axial displacement of the adjusting mandrel (5) when it is reversed is greater than or equal to the axial displacement of the adjusting mandrel (5) when it is forwardly rotated.

3. A single-motor screw pump according to claim 2, characterized in that: The protruding structures are balls (403), each group of protruding structures includes a ball (403), and the balls (403) are intermittently rollingly connected in the corresponding two inclined groove structures (501).

4. A single-motor screw pump according to claim 3, characterized in that: The lower end of the outer wall of the adjustment sleeve (402) is provided with an annular groove, and at least one through hole group is provided on the annular groove. The ball (403) is arranged in the through hole group, and each through hole group includes two symmetrical through holes. The annular groove extends to the lower edge of the adjustment sleeve (402), and a first sleeve (404) is sleeved on the outer side of the annular groove to prevent the ball (403) from rolling outward.

5. A single-motor screw pump according to claim 4, characterized in that: The inclined groove structure (501) comprises a straight groove (5011), a forward rotation groove (5012) and a reverse rotation groove (5013); the forward rotation groove (5012) and the reverse rotation groove (5013) are connected in an "eight" shape on both sides of the axially arranged straight groove (5011); the forward rotation groove (5012) is a gentle inclined groove; the reverse rotation groove (5013) is provided with an inflection point section at the middle position; the front and rear sections of the inflection point section are both inclined sides in the same direction, and the inclined sides of the inflection point section are in opposite directions.

6. A single-motor screw pump according to claim 2, characterized in that: The protruding structures are fixedly arranged oblique teeth (403'), each group of the protruding structures has two oblique teeth (403') in an upright or inverted "eight" shape, a gap is provided between the two oblique teeth (403'), and the two oblique teeth (403') have the same slope as the oblique groove on the same side.

7. A single-motor screw pump according to any one of claims 1 to 6, characterized in that: It also includes an eccentric rod (13), which is arranged between the adjustment mandrel (5) and the rotor assembly, and the eccentric rod (13) is connected to the lower end of the adjustment mandrel (5) via a connecting portion (15); The connecting portion (15) comprises a fixing sleeve (1501), a fourth sleeve (1502) and a shaft elastic retaining ring (1503), and the fixing sleeve (1501) is tightly connected to the adjusting mandrel (5) and the eccentric rod (13) respectively through a spline and a radial tooth groove structure, ensuring that the fixing sleeve can remain stable during forward and reverse rotation.

8. A single-motor screw pump according to claim 7, characterized in that: It also includes a spring (14) designed on the eccentric rod (13) for providing sufficient downward pressure for the rotor assembly in a specific environment such as a horizontal well, thereby ensuring good contact and sealing between the stator and rotor assemblies.

9. A single-motor screw pump according to claim 1, characterized in that: An annular protrusion is arranged at the lower end of the inner wall of the second sleeve (8), and a bearing group (7) is arranged at the upper end of the annular protrusion. The inner wall and the outer wall of the bearing group (7) are respectively connected to the second sleeve (8) and the adjustment core shaft (5), so as to achieve a stabilizing and load-bearing effect on the adjustment core shaft (5).

10. A single-motor screw pump according to claim 9, characterized in that: The lower end of the annular protrusion is connected to a straightening sealing mechanism (9), the structure of which includes a bearing washer (901), a cylindrical roller bearing (902), a packing (903) and a gasket (904). The cylindrical roller bearing (902) is fixedly sleeved on the adjustment mandrel (5) and is used to straighten the adjustment mandrel (5) and isolate the solid-liquid mixture.

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