阅读说明：本技术 一种实心柱塞双管抽油泵及方法 (Solid plunger double-pipe oil well pump and method ) 是由 钱钦 魏斌 智勤功 张方圆 姜东� 郑强 徐建礼 刘丙生 张中慧 古光明 黄润晶 于 2020-05-29 设计创作，主要内容包括：本发明公开了一种实心柱塞双管抽油泵及方法,包括泵筒、柱塞、进液阀、出液阀,所述柱塞为实心柱塞,柱塞外壁与泵筒内壁滑动密封式连接；还包括：尾管,所述尾管上端口与泵筒下端口连接,尾管底端为盲端,所述尾管内部构成沉液腔,所述尾管开设径向的尾管进口和尾管出口,尾管出口所开设的位置高于尾管进口所开设的位置,所述进液阀、出液阀均设置于泵筒的径向外侧方,且出液阀位于进液阀的上方,所述进液阀的出口与尾管进口连通,所述出液阀的进口与尾管出口连通,出液阀的出口与泵筒上方的油管内部连通。本发明形成单独排液通道,消除泵内固定余隙。消除防冲距带来的二次余隙,彻底解决气体对抽油泵的影响。(The invention discloses a solid plunger double-pipe oil well pump and a method, comprising a pump barrel, a plunger, a liquid inlet valve and a liquid outlet valve, wherein the plunger is a solid plunger, and the outer wall of the plunger is connected with the inner wall of the pump barrel in a sliding sealing manner; further comprising: the tail pipe, the port is connected with pump barrel lower port on the tail pipe, and the tail pipe bottom is the cecum, the inside heavy liquid chamber that constitutes of tail pipe, radial tail pipe import and tail pipe export are seted up to the tail pipe, and the position that the tail pipe export was seted up is higher than the position that the tail pipe import was seted up, feed liquor valve, liquid valve all set up in the radial outside side of pump barrel, and the liquid valve is located the top of feed liquor valve, the export and the tail pipe import intercommunication of feed liquor valve, the import and the tail pipe export intercommunication of liquid valve, the export of liquid valve and the inside intercommunication of oil pipe above the pump barrel. The invention forms an independent liquid discharge channel and eliminates the fixed clearance in the pump. Eliminate the secondary clearance that the scour protection is apart from bringing, thoroughly solve the influence of gas to the oil-well pump.)

1. A solid plunger double-pipe oil well pump comprises a pump cylinder, a plunger, a liquid inlet valve and a liquid outlet valve, wherein the plunger is a solid plunger, and the outer wall of the plunger is connected with the inner wall of the pump cylinder in a sliding sealing manner;

it is characterized by also comprising:

the tail pipe, the port is connected with pump barrel lower port on the tail pipe, and the tail pipe bottom is the cecum, the inside heavy liquid chamber that constitutes of tail pipe, radial tail pipe import and tail pipe export are seted up to the tail pipe, and the position that the tail pipe export was seted up is higher than the position that the tail pipe import was seted up, feed liquor valve, liquid valve all set up in the radial outside side of pump barrel, and the liquid valve is located the top of feed liquor valve, the export and the tail pipe import intercommunication of feed liquor valve, the import and the tail pipe export intercommunication of liquid valve, the export of liquid valve and the inside intercommunication of oil pipe above the pump barrel.

2. The solid plunger double tube oil well pump of claim 1, wherein the plunger lower end extends into the tail tube and the plunger outer diameter is smaller than the tail tube inner diameter.

3. The solid plunger dual tube pump of claim 1 or 2, further comprising:

and the liquid discharge pipe is arranged on the radial outer side of the pump barrel, the lower end of the liquid discharge pipe is communicated with the outlet of the liquid outlet valve, and the upper end of the liquid discharge pipe is communicated with a radial oil inlet hole formed in the oil pipe.

4. The solid plunger double-tube oil well pump of claim 3, wherein the upper port of the pump barrel is connected with an oil tube, the outer diameter of the plunger is smaller than the inner diameter of the oil tube, and the upper end of the plunger is connected with a sucker rod.

5. The solid plunger double-tube oil well pump as claimed in claim 4, wherein the liquid inlet valve and the liquid outlet valve are common one-way traveling valves.

6. A solid plunger double tube pump as claimed in claim 1 or claim 2 wherein the plunger lower end is a tapered guide head.

7. A solid plunger double-pipe oil pumping method is characterized by comprising the following steps:

the sucker rod drives the plunger to descend into the pump barrel until the plunger collides with the pump, then the anti-impact distance is lifted, after the anti-impact distance is lifted, the bottom dead center of the plunger is still positioned in the tail pipe, and then the sucker rod can drive the plunger to normally pump up and down;

when the plunger moves upwards, crude oil enters the tail pipe and the pump barrel through the liquid inlet valve, if the entered crude oil is in a gas-liquid two-phase state, gas is upward and liquid is downward due to the action of gravity, most of the liquid is gathered in the liquid settling cavity of the tail pipe, most of the gas is gathered in the pump barrel, and the liquid settling cavity is full of the liquid after multiple times of swabbing;

after the liquid is fully deposited in the liquid depositing cavity, when the plunger moves downwards, the space in the pump barrel is firstly compressed, after the lower end of the plunger extends out of the pump barrel, the space in the pump barrel can be considered to be compressed to zero, the plunger continues to move downwards, then the space in the liquid depositing cavity is compressed, and as the liquid depositing cavity is fully deposited with the liquid and the liquid can not be compressed, the liquid and the gas can be forcibly discharged into an oil pipe on the pump through the liquid outlet valve and the liquid discharge pipe.

Technical Field

The invention relates to the technical field of deep pumping of a small-diameter rod pump of a low-permeability and ultra-low-permeability reservoir, in particular to a solid plunger double-pipe oil well pump and a method.

Background

Low-permeability and ultra-low permeability oil fields are generally low in liquid quantity and deep in liquid level, and if a large pump is used, production and supply are unbalanced, or the lower depth is limited due to large load. Although the pumping parameters are reduced to relieve the unbalanced supply and production situation of the oil field, in order to reach the oil well supply and production standard of which the daily production fluid is less than 2m3, a speed reducer needs to be replaced or a frequency conversion adjusting device needs to be added, so that extra cost investment is brought, and the problem of large load and low depth caused by overlarge pump diameter cannot be solved. Therefore, the method is a feasible method for deep pumping by adopting the oil pump with the small diameter.

The plunger of the oil well pump has a hollow structure and a solid structure, the hollow structure is not suitable for the small-diameter rod pump, because the diameter of the small-diameter rod pump is generally below 32mm, if the plunger is made into the hollow structure, the outer wall of a part is too thin, the strength and the service life of the part cannot meet the use requirement, and compared with the plunger of the solid structure, the plunger of the oil well pump is reliable for the small-diameter pump. In the deep pumping of low-permeability and ultra-low-permeability oil reservoirs, the production pressure difference is large, and the crude oil is easy to separate out dissolved gas, so that the normal work of an oil well pump is influenced. The existing solid plunger oil-well pump mainly comprises two types, one type is that a liquid inlet valve and a liquid outlet valve are arranged at the right lower end, liquid is discharged through a two-way structure, the liquid inlet valve, the liquid outlet valve and the two-way structure at the lower end are arranged together to generate a large clearance, the oil-well pump repeatedly pumps to cause gas to gather in the clearance to influence the work of the oil-well pump, and the gas lock can be caused in serious cases. The other is that the liquid inlet valve is arranged at the right lower end and the liquid outlet valve is arranged at the side surface, the structure reduces the fixed clearance to a certain extent, but after the plunger collides with the pump to lift up to the impact distance, a section of clearance is still generated between the lower dead center of the plunger and the liquid inlet valve, and the influence of gas cannot be completely overcome. Therefore, it is necessary to provide a small-diameter solid oil well pump capable of overcoming the influence of gas.

Publication (bulletin) No.: CN204941871U, publication (public notice) day: 2016-01-06 discloses an air lock prevention oil well pump with an oil inlet valve arranged outside the top of a pump barrel, which comprises an upper joint, an upper coupling and a lower coupling of the pump barrel, an oil pumping polished rod, a plunger and the pump barrel; the upper coupling of the pump cylinder is connected with an external oil inlet valve; the upper end of the external oil inlet valve is connected with an anti-backflow valve; the external oil inlet valve comprises an upper end round opening and a lower end round opening of a valve shell, a bias valve cavity, a valve ball and a return spring, and the axes of the upper end round opening and the lower end round opening of the valve shell are superposed with the axis of the oil pumping polished rod; the offset valve cavity is positioned at the outer side of the pump cylinder; the valve cavity is internally provided with a valve ball, the lower end seat of the return spring is arranged on the bottom wall of the offset valve cavity, and the offset valve cavity is communicated with a cavity from the lower end round opening of the valve shell to the upper end round opening of the valve shell. The anti-airlock oil well pump with the oil inlet valve arranged outside the top of the pump barrel not only eliminates the condition of gas release in the whole oil inlet and oil discharge process in principle, but also is not influenced by the gas content of liquid, thereby avoiding the occurrence of the phenomenon of airlock. And the structure is simple and the manufacture is easy.

Publication (bulletin) No.: CN2547902Y, publication (public notice) day: 2003-04-30 relates to a leakage-proof and air-lock-proof high-efficiency oil well pump, which comprises a reducing joint, a pressure reducing pipe hoop, an annular valve, a pump barrel, a plunger assembly, an elastic valve pipe hoop, an oil outlet, a center cover, an elastic claw, an oil inlet valve ball, a ball seat, an oil inlet valve working barrel and the like. The pump can reduce the influence of gas on an oil well pump in an oil well with a high oil-gas ratio and prevent air lock; the valve ball centralizing and strong closing function is used in a directional inclined well and a sidetracking horizontal well, the valve ball centralizing and strong closing function is used in a deep well or an ultra-deep well, the influence of liquid column pressure or pump hanging depth is avoided, and the leakage of a clearance between a piston and a pump cylinder and the leakage of a pump valve can be reduced; in addition, the flow resistance of the entering oil is reduced due to the large flow passage area of the oil inlet of the pump barrel, and the pump has a sand prevention function. Because the utility model has the characteristics of rational in infrastructure, construction are simple and convenient, the pump efficiency is high, longe-lived, consequently can extensively be used for the oil recovery of deep well ultra-deep well high oil gas ratio well and sidetracking horizontal well.

Publication (bulletin) No.: CN110894779A, publication (public notice) day: 2020-03-20 an anti-sticking and anti-gas oil-well pump and oil pumping method, a sand scraping ring and an automatic compensation combined sealing ring assembly are arranged on the outer wall of a strong open-close anti-gas oil outlet valve assembly and tightly attached to a pump cylinder to form an anti-sand sticking structure and a tightly attached anti-sand sticking structure, when the pump barrel moves up and down, the dirt deposited on the inner wall of the pump barrel is scraped off while the sand is prevented from entering the pump cavity, the sand jam is prevented, the upper air-lock prevention valve is seated on the oil outlet valve seat when the oil pumping rod drives the pull rod to move up, the upper air-lock prevention valve is opened to suck the liquid, when the upper push block drives the lower valve rod of the upper air-lock prevention valve to move downwards, the fixed valve ball is opened, fluid in the pump cavity passes through an inner hole of the fixed valve seat, and liquid drainage from the pump to an oil pipe is realized; the strong open-close gas-proof oil outlet valve assembly is tightly matched with the spherical valve surface, so that the universal sealing performance and the effective work are ensured.

The technical scheme of the disclosed technology, the technical problems to be solved and the beneficial effects are all different from the technical scheme of the invention, or the technical field or the application occasion is different, and no technical inspiration exists in the technical scheme disclosed above.

Disclosure of Invention

The invention aims to provide a solid plunger double-pipe oil well pump and a method thereof aiming at the defects in the prior art, and a single liquid discharge channel is formed by double-pipe design and double-valve side arrangement, so that a fixed clearance in the pump is eliminated. Through the tail pipe closed liquid-sinking design, the secondary clearance brought by the scour prevention distance is eliminated, and the influence of gas on the oil well pump is thoroughly solved.

In order to achieve the purpose, the invention adopts the following technical scheme:

a solid plunger double-pipe oil well pump comprises a pump cylinder, a plunger, a liquid inlet valve and a liquid outlet valve, wherein the plunger is a solid plunger, and the outer wall of the plunger is connected with the inner wall of the pump cylinder in a sliding sealing manner;

further comprising:

the tail pipe, the port is connected with pump barrel lower port on the tail pipe, and the tail pipe bottom is the cecum, the inside heavy liquid chamber that constitutes of tail pipe, radial tail pipe import and tail pipe export are seted up to the tail pipe, and the position that the tail pipe export was seted up is higher than the position that the tail pipe import was seted up, feed liquor valve, liquid valve all set up in the radial outside side of pump barrel, and the liquid valve is located the top of feed liquor valve, the export and the tail pipe import intercommunication of feed liquor valve, the import and the tail pipe export intercommunication of liquid valve, the export of liquid valve and the inside intercommunication of oil pipe above the pump barrel.

Furthermore, the lower end of the plunger extends into the tail pipe, and the outer diameter of the plunger is smaller than the inner diameter of the tail pipe.

Further, still include:

and the liquid discharge pipe is arranged on the radial outer side of the pump barrel, the lower end of the liquid discharge pipe is communicated with the outlet of the liquid outlet valve, and the upper end of the liquid discharge pipe is communicated with a radial oil inlet hole formed in the oil pipe.

Furthermore, the upper port of the pump barrel is connected with an oil pipe, the outer diameter of the plunger is smaller than the inner diameter of the oil pipe, and the upper end of the plunger is connected with a sucker rod.

Furthermore, the liquid inlet valve and the liquid outlet valve are common one-way traveling valves.

Further, the lower end of the plunger is provided with a conical guide head.

In order to achieve the purpose, the invention adopts the following technical scheme:

a solid plunger double-pipe oil pumping method comprises the following steps:

the sucker rod drives the plunger to descend into the pump barrel until the plunger collides with the pump, then the anti-impact distance is lifted, after the anti-impact distance is lifted, the bottom dead center of the plunger is still positioned in the tail pipe, and then the sucker rod can drive the plunger to normally pump up and down;

when the plunger moves upwards, crude oil enters the tail pipe and the pump barrel through the liquid inlet valve, if the entered crude oil is in a gas-liquid two-phase state, gas is upward and liquid is downward due to the action of gravity, most of the liquid is gathered in the liquid settling cavity of the tail pipe, most of the gas is gathered in the pump barrel, and the liquid settling cavity is full of the liquid after multiple times of swabbing;

after the liquid is fully deposited in the liquid depositing cavity, when the plunger moves downwards, the space in the pump barrel is firstly compressed, after the lower end of the plunger extends out of the pump barrel, the space in the pump barrel can be considered to be compressed to zero, the plunger continues to move downwards, then the space in the liquid depositing cavity is compressed, and as the liquid depositing cavity is fully deposited with the liquid and the liquid can not be compressed, the liquid and the gas can be forcibly discharged into an oil pipe on the pump through the liquid outlet valve and the liquid discharge pipe.

Compared with the prior art, the invention has the following beneficial effects:

the liquid inlet valve and the liquid outlet valve are arranged on the side surface, and an independent liquid discharge pipe is arranged to communicate the liquid outlet valve with the oil feeding pipe of the pump. When the plunger piston moves upwards, crude oil enters the tail pipe and the pump barrel through the liquid inlet valve, and when the plunger piston moves downwards, the crude oil is discharged into an oil feeding pipe of the pump through the liquid outlet valve and the liquid discharge pipe, and liquid is always deposited in the tail pipe in the period, so that a liquid deposition cavity is formed. After the oil well pump is lifted to the anti-impact distance, the bottom dead center of the plunger is still positioned in the tail pipe and is always lower than the liquid inlet valve and the liquid outlet valve, so that the plunger sinks into liquid of the tail pipe when moving to the bottom dead center, even if gas exists in the pump, the gas can be discharged forcibly, and no clearance space for gas collection exists.

Through the double-barrelled design, the cooperation bivalve side is put, forms independent flowing back passageway, eliminates the internal fixed clearance of pump. Through the tail pipe closed liquid-sinking design, the secondary clearance brought by the scour prevention distance is eliminated, and the influence of gas on the oil well pump is thoroughly solved.

Drawings

FIG. 1 is a schematic structural diagram of a solid plunger double-tube oil well pump according to the present invention.

In the figure: 1-a liquid discharge pipe; 2-a liquid outlet valve; 3-liquid inlet valve; 4-a sucker rod; 5-oil pipe; 6-plunger piston; 7-a pump cylinder; 8-tail pipe; 9-heavy liquid chamber.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

referring to fig. 1, the present invention provides a technical solution:

a solid plunger double-pipe oil well pump comprises a pump cylinder 7, a plunger 6, a liquid inlet valve 3 and a liquid outlet valve 2, wherein the plunger is a solid plunger, and the outer wall of the plunger is connected with the inner wall of the pump cylinder in a sliding sealing manner;

further comprising:

the tail pipe 8, the port is connected with pump barrel lower port on the tail pipe, and the tail pipe bottom is the cecum, the inside heavy liquid chamber 9 that constitutes of tail pipe, radial tail pipe import and tail pipe export are seted up to the tail pipe, and the position that the tail pipe export was seted up is higher than the position that the tail pipe import was seted up, feed liquor valve, liquid valve all set up in the radial outside side of pump barrel, and the liquid valve is located the top of feed liquor valve, the export and the tail pipe import intercommunication of feed liquor valve, the import and the tail pipe export intercommunication of liquid valve, the export of liquid valve and the inside intercommunication of oil pipe 5 above the pump barrel.

Further, the lower end of the plunger 6 extends into the tail pipe, and the outer diameter of the plunger is smaller than the inner diameter of the tail pipe.

Further, still include:

and the liquid discharge pipe 1 is arranged on the radial outer side of the pump barrel, the lower end of the liquid discharge pipe is communicated with the outlet of the liquid outlet valve, and the upper end of the liquid discharge pipe is communicated with a radial oil inlet hole formed in the oil pipe.

Furthermore, the upper port of the pump cylinder is connected with an oil pipe, the outer diameter of the plunger is smaller than the inner diameter of the oil pipe, and the upper end of the plunger is connected with the sucker rod 4.

Furthermore, the liquid inlet valve and the liquid outlet valve are commonly used one-way traveling valves in the field, and are known in the prior art.

Further, the lower end of the plunger is provided with a conical guide head.

The oil well pump consists of a plunger 6, a pump barrel 7, a liquid discharge pipe 1, a liquid inlet valve 3, a liquid outlet valve 2 and a tail pipe 8, wherein the liquid inlet valve 3 and the liquid outlet valve 2 are arranged on the side surfaces, and the liquid outlet valve 2 is communicated with an oil feeding pipe 5 of the pump through the independent liquid discharge pipe 1. When the plunger 6 moves upwards, crude oil enters the tail pipe 8 and the pump barrel 7 through the liquid inlet valve 3, and when the plunger 6 moves downwards, the crude oil is discharged into the pump oil feeding pipe 5 through the liquid outlet valve 2 and the liquid discharge pipe 1, and during the period, the tail pipe 8 is always full of liquid to form a liquid sinking cavity 9. After the oil well pump is lifted to the anti-impact distance, the bottom dead center of the plunger 6 is still positioned in the tail pipe 8 and is always lower than the liquid inlet valve 3 and the liquid outlet valve 2, so that the plunger 6 sinks into the liquid of the tail pipe 8 when moving to the bottom dead center, even if gas exists in the pump, the gas can be forcibly discharged, and no clearance space for gas accumulation exists.

It is clear to those skilled in the art that the bottom dead center or the top dead center of the plunger 6 is the prior art in this field, and in short, the axial sliding stroke of the plunger, that is, the top dead center ensures that the plunger does not come off the upper end of the pump barrel, and the bottom dead center ensures that the plunger does not abut against the blind end of the tail pipe.

During construction, the oil pipe 5 with the pump barrel firstly goes into the well, the sucker rod 4 with the plunger 6 goes into the pump barrel until colliding with the pump, then the anti-impact distance is lifted, after the anti-impact distance is lifted, the bottom dead center of the plunger 6 is still positioned in the tail pipe 8, and then the sucker rod 4 can drive the plunger 6 to normally pump up and down. When the plunger 6 moves upwards, crude oil enters the tail pipe 8 and the pump barrel 7 through the liquid inlet valve 3, if the entering crude oil is in a gas-liquid two-phase state, gas is upward and liquid is downward due to the action of gravity, most of the liquid is gathered in the liquid settling cavity 9 of the tail pipe 8, most of the gas is gathered in the pump barrel 7, and the liquid settling cavity 9 is full of the liquid after multiple times of pumping; when the plunger 6 descends, the space in the pump barrel 7 is firstly compressed, after the lower end of the plunger 6 extends out of the pump barrel, the space in the pump barrel can be considered to be compressed to zero, the plunger 6 continues to descend, then the space in the sinking liquid cavity 9 is compressed, and as the sinking liquid cavity 9 is full of liquid and the liquid is incompressible, the liquid and the gas can be forcibly discharged into the pump oil feeding pipe 5 through the liquid outlet valve 2 and the liquid discharge pipe 1.

1. Through the double-barrelled design, the cooperation bivalve side is put, forms independent flowing back passageway, eliminates the internal fixed clearance of pump.

2. Through the design of tail pipe 8 sealing the liquid, the secondary clearance brought by the anti-impact distance is eliminated, and the influence of gas on the oil well pump is thoroughly solved.

Example 2:

referring to fig. 1, the present invention provides a technical solution:

a solid plunger double-pipe oil well pump comprises a pump cylinder 7, a plunger 6, a liquid inlet valve 3 and a liquid outlet valve 2, wherein the plunger is a solid plunger, and the outer wall of the plunger is connected with the inner wall of the pump cylinder in a sliding sealing manner;

further comprising:

the tail pipe 8, the port is connected with pump barrel lower port on the tail pipe, and the tail pipe bottom is the cecum, the inside heavy liquid chamber 9 that constitutes of tail pipe, radial tail pipe import and tail pipe export are seted up to the tail pipe, and the position that the tail pipe export was seted up is higher than the position that the tail pipe import was seted up, feed liquor valve, liquid valve all set up in the radial outside side of pump barrel, and the liquid valve is located the top of feed liquor valve, the export and the tail pipe import intercommunication of feed liquor valve, the import and the tail pipe export intercommunication of liquid valve, the export of liquid valve and the inside intercommunication of oil pipe 5 above the pump barrel.

Furthermore, the lower end of the plunger 6 extends into the tail pipe, the outer diameter of the plunger is smaller than the inner diameter of the tail pipe, and the lowest end of the plunger is lower than the inlet of the tail pipe.

Further, still include:

and the liquid discharge pipe 1 is arranged on the radial outer side of the pump barrel, the lower end of the liquid discharge pipe is communicated with the outlet of the liquid outlet valve, and the upper end of the liquid discharge pipe is communicated with a radial oil inlet hole formed in the oil pipe.

Example 3:

referring to fig. 1, the present invention provides a technical solution:

a solid plunger double-pipe oil well pump comprises a pump cylinder 7, a plunger 6, a liquid inlet valve 3 and a liquid outlet valve 2, wherein the plunger is a solid plunger, and the outer wall of the plunger is connected with the inner wall of the pump cylinder in a sliding sealing manner;

further comprising:

the tail pipe 8, the port is connected with pump barrel lower port on the tail pipe, and the tail pipe bottom is the cecum, the inside heavy liquid chamber 9 that constitutes of tail pipe, radial tail pipe import and tail pipe export are seted up to the tail pipe, and the position that the tail pipe export was seted up is higher than the position that the tail pipe import was seted up, feed liquor valve, liquid valve all set up in the radial outside side of pump barrel, and the liquid valve is located the top of feed liquor valve, the export and the tail pipe import intercommunication of feed liquor valve, the import and the tail pipe export intercommunication of liquid valve, the export of liquid valve and the inside intercommunication of oil pipe 5 above the pump barrel.

Furthermore, the lower end of the plunger 6 extends into the tail pipe, the outer diameter of the plunger is smaller than the inner diameter of the tail pipe, and the lowest end of the plunger is lower than the inlet of the tail pipe.

Although fig. 1 is used for all the above embodiments, it is obvious to those skilled in the art that a separate drawing is not shown as long as the parts or structural features missing in the embodiments are removed from the drawing. As will be clear to the skilled person. Of course, the embodiments with more components are only the best embodiments, and the embodiments with less components are the basic embodiments, but the basic objects of the invention can also be achieved, so all of them are within the protection scope of the invention.

All parts and parts which are not discussed in the present application and the connection mode of all parts and parts in the present application belong to the known technology in the technical field, and are not described again. Such as welding, threaded connections, etc.

In the present invention, the term "plurality" means two or more unless explicitly defined otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or unit must have a specific direction, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.