阅读说明：本技术 一种容积式挠性转子潜油电泵 (Positive displacement flexible rotor electric submersible pump ) 是由 王曦梅 张殿强 李冬 于 2020-05-14 设计创作，主要内容包括：本发明公开了一种容积式挠性转子潜油电泵,包括：泵座组件,主轴,串联在主轴上的末段泵体、至少一组中间段泵体、首段泵体,泵壳,和泵头组件；泵座与末段泵体之间、以及首段泵体与泵头之间均设置端板组件；每相邻两段泵体之间均设置有过渡腔组件；端板、挡板和过渡腔板上均开有轴向通流孔,过渡腔板在与挡板配合侧开有一定宽度的换向腔,各段泵体均包括定子,与主轴间隙配合键连接的转子花键套,与转子花键套花键连接的转子；转子为挠性转子。本发明采用挠性转子、高次曲线定子内腔、轴向流道设计,使容积式挠性转子潜油电泵具有良好的油井采油性能；能够满足潜油电泵长时间高速运行及油液含砂、含气工况的工作要求,且效率高,扬程大。(The invention discloses a positive displacement flexible rotor electric submersible pump, which comprises: the pump comprises a pump base assembly, a main shaft, a tail-section pump body, at least one group of middle-section pump bodies, a head-section pump body, a pump shell and a pump head assembly, wherein the tail-section pump body, the at least one group of middle-section pump bodies, the head-section pump bodies, the pump shell and the pump head; end plate assemblies are arranged between the pump base and the tail pump body and between the first pump body and the pump head; a transition cavity assembly is arranged between every two adjacent sections of pump bodies; axial through flow holes are formed in the end plate, the baffle plate and the transition cavity plate, a reversing cavity with a certain width is formed in the matching side of the transition cavity plate and the baffle plate, each section of the pump body comprises a stator, a rotor spline housing in clearance fit key connection with the main shaft and a rotor in spline connection with the rotor spline housing; the rotor is a flexible rotor. The invention adopts the design of the flexible rotor, the inner cavity of the high-order curve stator and the axial flow channel, so that the positive displacement flexible rotor submersible electric pump has good oil well oil production performance; the working requirements of long-time high-speed operation of the electric submersible pump and working conditions of sand and gas in oil can be met, the efficiency is high, and the lift is large.)

1. A positive displacement flexible rotor electrical submersible pump, comprising:

the pump comprises a pump base assembly, a main shaft, a tail-section pump body, at least one group of middle-section pump bodies, a head-section pump body, a pump shell and a pump head assembly, wherein the tail-section pump body, the at least one group of middle-section pump bodies, the head-section pump bodies, the pump shell and the pump head assembly;

the pump base assembly comprises a pump base, a bearing support in interference fit with the pump base and a bearing bush in interference fit with the bearing support; the pump head assembly comprises a pump head, a bearing support in interference fit with the pump head and a bearing bush in interference fit with the bearing support; bearing sleeves are arranged between the pump seat assembly and the main shaft and between the pump head assembly and the main shaft, and are in keyed connection and positioning on the main shaft and are in clearance fit with a bearing bush in the pump seat assembly and a bearing bush in the pump head assembly correspondingly;

end plate assemblies which are mutually matched in a pressing manner are arranged between the pump base and the tail section of the pump body and between the first section of the pump body and the pump head; the end plate assembly comprises an end plate, an outer shaft sleeve I and an inner shaft sleeve I, wherein the outer shaft sleeve I is connected with the end plate in a positioning mode through a shaft sleeve pin block, and the inner shaft sleeve I is connected with the main shaft in a clearance fit key mode;

a transition cavity assembly which is mutually pressed and matched is arranged between every two adjacent sections of pump bodies; the transition cavity assembly comprises a baffle plate, a transition cavity plate in compression fit connection with the baffle plate, an outer shaft sleeve II in positioning connection with the baffle plate and the transition cavity plate through shaft sleeve pin blocks respectively, and an inner shaft sleeve II in clearance fit key connection with the main shaft;

two axial through flow holes which are symmetrical relative to the axis are formed in the end plate, the baffle and the transition cavity plate, the contour curve of each axial through flow hole is formed by combining the outer diameter of a rotor, the high-order square curve of an inner cavity of a stator and the bending curve of two adjacent blades on the rotor, and a reversing cavity with a certain width is formed in the transition cavity plate along the contour of the outer side of the axial through flow hole of the transition cavity plate on the side matched with the baffle to reach the contour of the outer side of the axial through flow hole of the baffle; pin holes are formed in the end plate, the baffle plate and the transition cavity plate and used for assembling and fixing;

the tail-section pump body, the middle-section pump body and the head-section pump body respectively comprise a stator, a rotor spline housing in clearance fit key connection with the main shaft, and a rotor in spline fit connection with the rotor spline housing; the stator is provided with a pin hole for assembly and fixation, the rotor is a flexible rotor, and blades of the rotor and the rotor are integrally formed; the two ends of the stator of the tail-section pump body and the first-section pump body are respectively connected with the corresponding transition cavity assembly and the end plate in a positioning mode through positioning pins and stepped holes, and the two ends of the stator of the middle-section pump body are respectively connected with the corresponding transition cavity assembly in a positioning mode through positioning pins and stepped holes;

the pump shell is matched with each section of the pump body and each transition cavity assembly, and two ends of the pump shell are respectively in threaded connection with the pump base and the pump head.

2. The positive displacement flexible rotor electrical submersible pump of claim 1 wherein a metallic inner core is embedded within the cylindrical body of the blade end of each of the rotors.

3. The positive displacement flexible rotor electric submersible pump according to claim 1, wherein each of the rotors is made of an elastic wear resistant material such as neoprene, nitrile rubber, silicone, epdm, or urethane rubber.

4. The positive displacement flexible rotor electrical submersible pump according to claim 1, wherein the cavity curve of each stator is composed of two large arc curves, two small arc curves, and four high order square curves.

5. The positive displacement flexible rotor electrical submersible pump according to claim 4, wherein the four sections of higher power curve equations are the same and are all established on a polar coordinate system, and each section of the higher power curve is divided into a first transition curve and a second transition curve:

the polar coordinate expression of the first transition curve is as follows:

ρ＝r+8(R-r)[11(θ/a)⁴-60(θ/a)⁵+152(θ/a)⁶-192(θ/a)⁷+96(θ/a)⁸](0≤θ≤a/2)

the polar coordinate expression of the second transition curve is as follows:

ρ＝R-8(R-r)[7-80(θ/a)+402(θ/a)²-1140(θ/a)³+1191(θ/a)⁴-2196(θ/a)⁵+1496(θ/a)⁶-576(θ/a)⁷+96(θ/a)⁸](a/2≤θ≤a)

wherein rho is the polar diameter of a point on the high-order square curve, theta is the polar angle of a point on the high-order square curve, a is the total angle of the high-order square curve, R is the radius of the large circular arc of the stator inner cavity, and R is the radius of the small circular arc of the stator inner cavity.

6. The positive displacement flexible rotor electrical submersible pump of claim 1 wherein the baffle is in a compression connection with the transition chamber plate via a stepped bore.

7. The positive displacement flexible rotor electrical submersible pump of claim 1 wherein the baffle is integrally formed with the transition chamber plate.

8. The positive displacement flexible rotor electrical submersible pump as claimed in claim 1, wherein each of the bearing housing, the first inner and outer bearing housings, and the second inner and outer bearing housings is made of brass or phenolic cloth.

Technical Field

The invention belongs to the technical field of submersible electric pumps for oil extraction in oil fields, and particularly relates to a positive displacement flexible rotor submersible electric pump.

Background

The main oil extraction process equipment at present comprises an electric submersible pump, a screw pump, an oil pumping unit, an electric submersible plunger pump, a hydraulic piston pump, a hydraulic jet pump, a gas lift and the like. The main force equipment for underground oil production is centrifugal submersible electric pump and positive displacement screw pump. The electric submersible pump has the advantages of large displacement range, long pump detection period, high technical maturity and the like, but also has the problems of low single-stage lift, large assembly length and low pump efficiency; the screw pump has the advantages of high volumetric efficiency, high viscosity and good working condition effect of high gas content, but also has the defects of low rotating speed, easy abrasion of sand content and short pump detection period. The basic principle of the displacement pump is reasonably utilized, the high efficiency and high-lift characteristics of the displacement pump are exerted, the defects of low common rotating speed, vane emptying and solid particle contact abrasion of the displacement pump are overcome, the displacement submersible electric pump which is suitable for high rotating speed, long operation time, strong sand passing capability and high pump efficiency is designed and developed, and the displacement submersible electric pump has important theoretical significance and higher economic value for quality improvement and efficiency improvement of the industry.

The application number CN201720049637.9 patent discloses a lifting device of a petroleum well oil extraction vane pump, which uses the vane pump to replace an impeller and a guide wheel as a main body structure of the pump, thereby improving the pump efficiency; and a hydraulic push rod is used for providing radial supporting force for the sliding sheet so that the sliding sheet is always attached to the inner wall of the stator. But the contact part of the rotor and the stator has sand grinding, and the sand can enter the back cavity of the sliding vane through the oil guide channel on the rotor to form the accumulation of the sand, so that the sliding vane is blocked; meanwhile, the through hole is formed in the transmission shaft, so that the hydraulic push rod penetrates through the main shaft, the hydraulic push rod can generate shear stress due to machining errors and rotation errors between the transmission shaft and the rotor, resistance is generated on the movement of the hydraulic push rod, and the strength of the transmission shaft is reduced due to the through hole in the transmission shaft.

The application number CN88206389 discloses a sliding-vane electric submersible pump, which consists of a pump body part, a sand control device, a protector and a motor. This patent is with the pump main part of latent oily charge pump change for single section gleitbretter pump, and the progression is few (single-stage), simple structure, light in weight, pressure are high, efficient (the pump efficiency can reach 90%, saves 1/3 ~ 1/2 electric power than the pole pump). But the pump has only a single section and limited lift, is suitable for oil wells with medium and low production capacity, and does not improve the problem of grit abrasion.

The application number cn201220106395.x patent discloses a submersible sliding vane pump oil production system, comprising: the oil-submersible motor, the protector, the coupling, the sliding vane pump, the oil pipe, the cable and the controller. The axial flow sliding vane pump in the system belongs to a displacement pump, the system efficiency is high, the discharge capacity can be adjusted according to the rotating speed of a motor, and the system can be used for lifting gas-containing crude oil. However, the patent does not describe the internal structure of the sliding vane pump, i.e. the traditional structure of the sliding vane pump is not improved, the phenomenon of sliding vane emptying may occur in some low-speed occasions, the working performance is affected, and the problem of sand abrasion still exists.

The application No. 201210054052.8 patent discloses a crude oil lift system and method for transporting fluids using a sliding vane pump. This patent adopts the axial oil circuit, has reduced the radial dimension and the radial volume of gleitbretter pump, can adapt to narrow and small tubulose space. The double-acting sliding vane pump is provided with four sliding vanes, so that the condition that an oil inlet cavity is communicated with an oil discharge cavity can occur in the moving process, and pressure loss and flow loss are generated; the use of rolling bearings as supports for the shaft places certain restrictions on the size and service life of the pump; without the slider pretension arrangement, slider voiding may occur during operation.

In summary, the sliding vane pump structure applied to the electric submersible pump at present has the following problems: firstly, no sand passing design is designed for sand-containing oil, and gravel abrasion and even pump blockage can be caused at the contact part of parts; secondly, most sliding vane pump structures are used, the phenomenon of sliding vane cavitation affects the pump efficiency and the discharge capacity, and the phenomenon of cavitation exists; thirdly, most of the sliding vane pumps use rolling bearings as main shaft supports, so that the size and the service life of the sliding vane pumps are limited to a certain extent; and fourthly, no special design is provided for the working condition of the sliding vane pump in high-speed and long-time operation.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a positive displacement flexible rotor electric submersible pump, which adopts a flexible rotor structure as a pump main body part of the electric submersible pump, so that the electric submersible pump has stronger self-priming performance and high self-priming speed, and a rotor blade can be effectively kept to be attached to an inner cavity of a stator by adopting a high-strength elastic material; the double-acting pump type design of the pump cavity based on the high-order square curve and the arc curve is beneficial to improving the high-speed stability of the pump and improving the pump efficiency and flow; a metal inner core is embedded in a cylinder at the end part of the rotor blade, so that the centrifugal force action of the blade is enhanced; the bearing sleeve and the inner and outer shaft sleeves are used as supports of the main shaft, so that the pump has a simple structure and long service life and does not need special lubricating design; the axial flow channel design enables axial flow of liquid in the case of limited space. The invention utilizes the performance of the flexible pump to convey solid particles and gas-containing oil, so that the electric submersible pump can meet the working requirements of long-time high-speed operation and working conditions of sand and gas-containing oil, and has high efficiency and large lift.

The invention is realized in this way, a flexible submersible electric pump with positive displacement rotor, comprising:

the pump comprises a pump base assembly, a main shaft, a tail-section pump body, at least one group of middle-section pump bodies, a head-section pump body, a pump shell and a pump head assembly, wherein the tail-section pump body, the at least one group of middle-section pump bodies, the head-section pump bodies, the pump shell and the pump head assembly;

the pump base assembly comprises a pump base, a bearing support in interference fit with the pump base and a bearing bush in interference fit with the bearing support; the pump head assembly comprises a pump head, a bearing support in interference fit with the pump head and a bearing bush in interference fit with the bearing support; bearing sleeves are arranged between the pump seat assembly and the main shaft and between the pump head assembly and the main shaft, and are in keyed connection and positioning on the main shaft and are in clearance fit with a bearing bush in the pump seat assembly and a bearing bush in the pump head assembly correspondingly;

end plate assemblies which are mutually matched in a pressing manner are arranged between the pump base and the tail section of the pump body and between the first section of the pump body and the pump head; the end plate assembly comprises an end plate, an outer shaft sleeve I and an inner shaft sleeve I, wherein the outer shaft sleeve I is connected with the end plate in a positioning mode through a shaft sleeve pin block, and the inner shaft sleeve I is connected with the main shaft in a clearance fit key mode;

a transition cavity assembly which is mutually pressed and matched is arranged between every two adjacent sections of pump bodies; the transition cavity assembly comprises a baffle plate, a transition cavity plate in compression fit connection with the baffle plate, an outer shaft sleeve II in positioning connection with the baffle plate and the transition cavity plate through shaft sleeve pin blocks respectively, and an inner shaft sleeve II in clearance fit key connection with the main shaft;

two axial through flow holes which are symmetrical relative to the axis are formed in the end plate, the baffle and the transition cavity plate, the contour curve of each axial through flow hole is formed by combining the outer diameter of a rotor, the high-order square curve of an inner cavity of a stator and the bending curve of two adjacent blades on the rotor, and a reversing cavity with a certain width is formed in the transition cavity plate along the contour of the outer side of the axial through flow hole of the transition cavity plate on the side matched with the baffle to reach the contour of the outer side of the axial through flow hole of the baffle; pin holes are formed in the end plate, the baffle plate and the transition cavity plate and used for assembling and fixing;

the tail-section pump body, the middle-section pump body and the head-section pump body respectively comprise a stator, a rotor spline housing in clearance fit key connection with the main shaft, and a rotor in spline fit connection with the rotor spline housing; the stator is provided with a pin hole for assembly and fixation, the rotor is a flexible rotor, and blades of the rotor and the rotor are integrally formed; the two ends of the stator of the tail-section pump body and the first-section pump body are respectively connected with the corresponding transition cavity assembly and the end plate in a positioning mode through positioning pins and stepped holes, and the two ends of the stator of the middle-section pump body are respectively connected with the corresponding transition cavity assembly in a positioning mode through positioning pins and stepped holes;

the pump shell is matched with each section of the pump body and each transition cavity assembly, and two ends of the pump shell are respectively in threaded connection with the pump base and the pump head.

In the above technical solution, preferably, a metal core is embedded in a cylinder at a blade end of each of the rotors.

In the above technical solution, preferably, each of the rotors is made of elastic wear-resistant materials such as neoprene, nitrile rubber, silica gel, ethylene propylene diene monomer or polyurethane rubber.

In the above technical solution, preferably, the cavity curve of each stator is composed of two large arc curves, two small arc curves, and four high-order square curves.

In the foregoing technical solution, it is further preferable that the four high-order square curve equations are the same and are all established on a polar coordinate system, and each high-order square curve is divided into a first transition curve and a second transition curve:

the polar coordinate expression of the first transition curve is as follows:

ρ＝r+8(R-r)[11(θ/a)⁴-60(θ/a)⁵+152(θ/a)⁶-192(θ/a)⁷+96(θ/a)⁸](0≤θ≤a/2)

the polar coordinate expression of the second transition curve is as follows:

ρ＝R-8(R-r)[7-80(θ/a)+402(θ/a)²-1140(θ/a)³+1191(θ/a)⁴-2196(θ/a)⁵+1496(θ/a)⁶-576(θ/a)⁷+96(θ/a)⁸](a/2≤θ≤a)

wherein rho is the polar diameter of a point on the high-order square curve, theta is the polar angle of a point on the high-order square curve, a is the total angle of the high-order square curve, R is the radius of the large circular arc of the stator inner cavity, and R is the radius of the small circular arc of the stator inner cavity.

In the above technical solution, preferably, the baffle plate and the transition cavity plate are connected by a stepped hole in a pressing manner.

In the above technical solution, preferably, the baffle plate and the transition cavity plate are integrally formed.

In the above technical solution, preferably, each of the bearing housing, the inner and outer shaft housings one and the inner and outer shaft housings two is made of brass or phenolic cloth plate, respectively.

The invention has the following advantages and beneficial effects:

1. the invention adopts the flexible rotor as the main structure of the pump, and has stronger self-absorption capacity and solid particle and gas-containing oil liquid transportation capacity;

2. the double-acting pump type design of the pump cavity based on the high-order square curve and the circular arc curve is beneficial to improving the high-speed stability of the pump and improving the pump efficiency and flow; the flexible rotor is made of high-strength elastic materials, so that the weight is light, and the power consumption is effectively reduced;

3. the axial flow channel design of the invention realizes the axial flow of liquid under the condition of limited space;

4. the invention uses the bearing sleeve and the inner and outer shaft sleeves as the support of the main shaft, so that the pump has simple structure and long service life and does not need special lubricating design.

5. According to the invention, the metal inner core is embedded in the cylinder at the end part of the rotor blade, so that the action of the centrifugal force of the blade is increased, and the performance of the blade attached to the inner cavity of the stator is improved.

6. The rotor of the invention is a flexible rotor, when the outlet valve is closed, the liquid can self-circulate in the pump, and the safety performance is higher; the only rotating part in the pump chamber, the flexible rotor, is free of metallic contact during operation, making operation almost noiseless.

7. The flexible rotor, the high-order curve stator inner cavity and the axial flow channel are designed, and the flexible rotor pump has the performance of conveying solid particles and gas, so that the positive displacement flexible rotor submersible electric pump has good oil well oil production performance; the working requirements of long-time high-speed operation of the electric submersible pump and working conditions of sand and gas in oil can be met, the efficiency is high, and the lift is large.

Drawings

Fig. 1 is a schematic structural diagram of a positive displacement flexible rotor submersible electric pump provided in embodiment 1 of the present invention;

fig. 2 is an axial cross-sectional schematic view at a-a of the flexible rotor submersible electric pump according to embodiment 1 of the present invention;

fig. 3 is an exploded schematic view of the positive displacement flexible rotor submersible electric pump provided in embodiment 1 of the present invention;

fig. 4a is a schematic structural view of a rotor provided in embodiment 1 of the present invention;

FIG. 4B is a cross-sectional view B-B of FIG. 4 a;

fig. 5a is a perspective view of a stator provided in embodiment 1 of the present invention;

fig. 5b is a front view of a stator provided in embodiment 1 of the present invention;

FIG. 5C is a cross-sectional view C-C of FIG. 5 b;

fig. 6a is a schematic structural view of a baffle plate provided in embodiment 1 of the present invention;

FIG. 6b is a cross-sectional view D-D of FIG. 6 a;

FIG. 6c is a cross-sectional view E-E of FIG. 6 a;

FIG. 7a is a schematic structural diagram of a transition cavity plate provided in embodiment 1 of the present invention;

FIG. 7b is a rear view of FIG. 7 a;

FIG. 7c is a cross-sectional view F-F of FIG. 7 a;

FIG. 8a is a schematic structural view of end plates at first and last stages according to embodiment 1 of the present invention;

FIG. 8b is a sectional view taken along line G-G of FIG. 8 a;

FIG. 8c is a cross-sectional view taken at H-H of FIG. 8 a;

FIG. 9a is a perspective view of a transition chamber provided in example 2 of the present invention;

FIG. 9b is a front view of a transition chamber provided in accordance with embodiment 2 of the present invention;

FIG. 9c is a rear view of FIG. 9 b;

fig. 9d is a cross-sectional view I-I of fig. 9 b.

In the figure: 1. a pump mount; 2. a pump housing; 3. a terminal plate at the end section; 4. a stator; 5. a baffle plate; 6. the inner shaft sleeve I; 7. a transition cavity plate; 8. a rotor; 9. a first end plate; 10. an axial through-flow aperture; 11. a commutation cavity; 12. a pump head; 13. a bearing support; 14. bearing bushes; 15. a bearing housing; 16. a first outer shaft sleeve; 17. a second outer shaft sleeve; 18. a shaft sleeve pin block; 19. a rotor spline housing; 20. a second inner shaft sleeve; 21. positioning pins; 22. a pin hole; 23. a clamp spring; 24. a key; 25. a main shaft; 26. a transition chamber; 27. a large circular arc curve; 28. a small circular arc curve; 29. a first transition curve; 30. and a second transition curve.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Technical features or combinations of technical features described in the embodiments below should not be considered as being isolated, and they may be combined with each other to achieve a better technical effect.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.