Linear electric motor and oil recovery apparatus

Abstract

A linear electric motor and an oil recovery apparatus comprising a linear electric motor. The linear electric motor comprises a stator module (1) and a mover module (2). The stator module (1) comprises a plurality of stator assemblies (11), each stator assembly (11) comprising an outer sleeve (111), an inner liner tube (112) and a coil winding (113), wherein the inner liner tube (112) and the coil winding (113) are arranged in the outer sleeve (111), and the coil winding (113) is on the inner liner tube (112) and is sealingly arranged between the outer sleeve (111) and the inner liner tube (112). The mover module (2) comprises a plurality of mover assemblies (21) and a mover connecting sleeve (22), each mover assembly (21) comprising a mover mandrel (211) and a permanent magnet (212), wherein the permanent magnet (212) is arranged on the outside of the mover mandrel (211), and an oil channel (213) is formed inside the mover mandrel (211). Two adjacent mover mandrels (211) are connected together by means of the mover connecting sleeve (22), and two adjacent oil channels (213) are in communication by means of the mover connecting sleeve. The mover module (2) is arranged in the stator module (1), wherein the mover mandrels (211) can slide in the inner liner tube (112), and an oil passage gap (10) is formed between the mover module (2) and the inner liner tube (112). Oil can flow between the oil channels and the oil passage gap on the basis of the difference between oil pressures. Therefore, the flowing oil can serve a heat-absorption cooling function; in addition, the flowing oil can not only reduce the resistance to the mover assemblies when the mover assemblies move upwards, but also provide a damping force when the mover assemblies move downwards, thereby improving the operation stability of the mover assemblies.

Description

Linear motors and oil extraction equipment Technical Field

[0001] This application relates to the field of mechanical technology, and in particular to a linear motor and oil extraction equipment. Background Technology

[0002] With the continuous improvement of oil extraction technology and the increasing difficulty of extraction, higher requirements are placed on oil production equipment. Currently, the development of downhole submersible linear motor technology and oil pump technology is often used to achieve the effect of downhole oil production and improve the service life of oil production equipment.

[0003] The linear motor oil extraction method involves placing the oil pump in the oil well, with the linear motor driving the pump to achieve the oil extraction operation. For example, Chinese Patent Publication No. CN112283063A discloses an integrated pump and motor oil extraction device and method, in which the stator of the linear motor is assembled into the pump barrel, and the mover acts as a plunger. Under the excitation magnetic field of the motor stator, the pump plunger reciprocates to achieve oil extraction. However, the pump barrel requires a certain strength and has a thick wall, resulting in a large air gap in the motor, which affects the motor efficiency. In addition, the pump plunger is integrated into the motor mover and located within the motor stator, requiring the pump plunger to cooperate with several ball valves built into the motor stator to achieve oil extraction. The overall structure is complex, and the oil extraction efficiency is low. Chinese Patent Publication No. CN108880178A discloses a multi-stage linear motor and its oil pump, using an independent linear motor and oil pump. However, during use, the linear motor needs to apply thrust to the oil pump. Due to the structural strength limitations of the linear motor, the stroke of the linear motor is relatively small, resulting in low oil extraction efficiency. Therefore, how to design a technology to improve oil extraction efficiency is the technical problem that this application aims to solve. Technical issues

[0004] The technical problem to be solved by this application is to provide a linear motor and oil extraction equipment to improve the reliability of the oil extraction equipment and increase the oil extraction efficiency. Technical solutions

[0005] The technical solution provided in this application is a linear motor, comprising:

[0006] The stator module includes multiple stator assemblies. Each stator assembly includes an outer tube, an inner tube, and a coil winding. The coil winding and the inner tube are disposed in the outer tube. The coil winding is sleeved on the inner tube and sealed between the outer tube and the inner tube. Two adjacent outer tubes are sealed together.

[0007] The mover module includes multiple mover components and a mover connecting sleeve. Each mover component includes a mover spindle and a permanent magnet. The permanent magnet is located outside the mover spindle, and an oil channel is formed inside the mover spindle. The side wall of the mover connecting sleeve is provided with a through opening. Two adjacent mover spindles are connected together through the mover connecting sleeve, and two adjacent oil channels are connected through the mover connecting sleeve.

[0008] The moving part module is set in the stator module, and the moving part spindle can slide in the inner liner tube, forming an oil passage gap between the moving part module and the inner liner tube.

[0009] In one embodiment of this application, the oil passage gap is connected to the oil fluid channel.

[0010] In one embodiment of this application, the oil passage is configured such that oil flows upward within the oil passage during the downward stroke of the mover spindle; the oil passage gap is configured such that oil flows upward within the oil passage gap during the downward stroke of the mover spindle.

[0011] In one embodiment of this application, the oil passage is configured such that oil flows downward within the oil passage during the upward stroke of the mover spindle; the oil passage gap is configured such that oil flows downward within the oil passage gap during the upward stroke of the mover spindle.

[0012] In one embodiment of this application, the stator assembly further includes two end seals, each end seal having a first mounting through hole; the end seals are sealed and inserted into the corresponding openings of the outer sleeve, and the end seals of the inner sleeve are sealed and inserted into the first mounting through hole; the coil winding is located between the two end seals, and the mover spindle passes through the first mounting through hole.

[0013] In one embodiment of this application, the stator module further includes a stator connector, which is provided with a second mounting through hole; two adjacent stator components are sealed and fixed together by the stator connector, and the stator connector is sealed and connected with the end seal of the corresponding end of the stator component, and the mover spindle passes through the second mounting through hole.

[0014] In one embodiment of this application, a first wiring hole is provided on the end seal, and a second wiring hole is provided on the stator connector; for the end seal and the stator connector connected together, the first wiring hole and the second wiring hole communicate with each other; the cable connected to the coil winding passes through the first wiring hole and the second wiring hole; the stator module also includes a motor head and an external terminal block, the motor head is also provided with a third mounting through hole, and the motor head is also provided with a wiring channel, the external terminal block is sealed in the wiring channel; the motor head is connected to the stator assembly at the top, and the third mounting through hole is configured to allow the rotor spindle to pass through; the cable connected to the coil winding also extends into the wiring channel and connects to the external terminal block.

[0015] In one embodiment of this application, the inner end face of the end seal is further provided with a first keyway, and the stator core of the coil winding is provided with a second keyway. The first keyway and the second keyway are connected, and the cable connected to the coil winding is also arranged in the first keyway and the second keyway.

[0016] In one embodiment of this application, the stator module further includes: a pressure balancing assembly, which includes an outer protective tube and a hydraulic pressure sensing component, the hydraulic pressure sensing component being disposed inside the outer protective tube; a first pressure balancing cavity is formed inside the hydraulic pressure sensing component, the first pressure balancing cavity being configured to be filled with electrical insulating oil; the hydraulic pressure sensing component is configured to deform under the hydraulic pressure inside the outer protective tube to adjust the pressure inside the first pressure balancing cavity; a second pressure balancing cavity is formed between the outer sleeve and the inner liner, the second pressure balancing cavity being configured to be filled with electrical insulating oil; wherein, the first pressure balancing cavity and the second pressure balancing cavity are connected.

[0017] In one embodiment of this application, the pressure balancing assembly is disposed between two adjacent stator assemblies, and the moving mandrel of at least one moving assembly is inserted into the outer sleeve; or, the pressure balancing assembly is disposed on the stator assembly located at the lower end of the stator module, and the moving mandrel of at least one moving assembly is inserted into the outer sleeve.

[0018] In one embodiment of this application, the first pressure balancing cavity is interconnected with the second pressure balancing cavity; or, two adjacent second pressure balancing cavities are interconnected, and the first pressure balancing cavity is interconnected with the second pressure balancing cavity in the bottom moving part assembly.

[0019] In one embodiment of this application, the stator assembly further includes two end seals, each end seal having a first mounting through hole; the end seals are sealed and inserted into the corresponding openings of the outer sleeve, and the end seals of the inner liner are inserted into the first mounting through hole; the outer sleeve and the inner liner form a second pressure balance cavity between the two end seals, the coil winding is located between the two end seals, and the mover spindle passes through the first mounting through hole.

[0020] In one embodiment of this application, the end seal is further provided with a first pressure communication hole, which communicates with a second pressure balance cavity; in two stator assemblies connected together, the first pressure communication hole in one stator assembly communicates with an adjacent first pressure communication hole in the other stator assembly.

[0021] In one embodiment of this application, the stator module further includes a stator connector, which is provided with a second mounting through hole and a second pressure communication hole; two adjacent stator components are sealed and fixedly connected together by the stator connector, and the stator connector is sealed and connected with the end seals at the corresponding ends of the stator components, and the mover spindle passes through the second mounting through hole; for the end seals and stator connectors connected together, the first pressure communication hole communicates with the second pressure communication hole.

[0022] In one embodiment of this application, the stator module further includes a motor head and external terminals. The motor head is also provided with a third mounting through hole, a wiring channel, and an oil injection hole. The oil injection hole and the wiring channel are arranged outside the third mounting through hole, and the external terminals are sealed in the wiring channel. The motor head is connected to the top stator assembly, and the third mounting through hole is configured to allow the rotor spindle to pass through. The cable connected to the coil winding extends into the wiring channel and is connected to the external terminals. The oil injection hole is connected to the adjacent second pressure balance chamber.

[0023] In one embodiment of this application, the linear motor further includes an upper buffer oil pipe and / or a lower buffer oil pipe; the upper buffer oil pipe is disposed at the top of the stator module, and the lower buffer oil pipe is disposed at the bottom of the stator module; the upper buffer oil pipe is configured to communicate with the upper moving mandrel, and the lower buffer oil pipe is configured to communicate with the lower moving mandrel.

[0024] And / or, the mover module also includes a lower buffer connection assembly, which includes two lower mounting seats and a lower spring connected between the two lower mounting seats. The upper lower mounting seat is connected to the mover spindle located at the bottom, and the lower lower mounting seat is configured to be connected to the oil pump.

[0025] This application also provides an oil production device, including an oil pump and the aforementioned linear motor. The oil pump is arranged below the linear motor, which is vertically arranged. The mover spindle of the mover assembly located at the bottom of the linear motor is connected to the oil pump.

[0026] This application also provides an oil production device, including an oil pump and the aforementioned linear motor. The linear motor is arranged laterally, and the oil pump is arranged at the rear end of the linear motor. The mover spindle of the mover assembly located at the rear end of the linear motor is connected to the oil pump. Beneficial effects

[0027] Compared with the prior art, the advantages and positive effects of this application are as follows: By assembling the mover module into the inner liner tube, an oil passage gap is formed between the mover module and the mover module tube, and an oil channel is formed in the mover spindle of the mover module. The oil passage gap and the oil channel are interconnected. During use, the oil pump is connected to the bottom of the mover module, and the mover spindle will provide a pulling force to the oil pump to lift the oil upward. In this way, the structural strength requirements of the mover spindle can be reduced, thereby extending the reciprocating stroke of the mover spindle to meet the usage requirements of oil pumps with different strokes, expanding the application range, making the working state of the oil pump more reasonable and reliable, enabling long-term stable operation, improving the oil pumping volume and efficiency, and extending the pump inspection cycle.

[0028] In addition, the oil passage formed by the mover spindle and the oil circuit gap between the mover module and the inner liner tube allow the oil pumped by the oil pump to flow upward. At the same time, the oil can flow between the oil passage and the oil circuit gap according to the oil pressure difference. In this way, during the reciprocating operation of the mover assembly, the oil can flow between the oil passage and the oil circuit gap. On the one hand, the flowing oil can absorb heat and cool down to improve the operational reliability of the linear motor. On the other hand, the flowing oil can reduce the resistance and pressure generated when the mover assembly moves upward, and can also provide a certain damping force to the mover assembly when it moves downward, so as to improve the smoothness and stability of the operation.

[0029] In addition, linear motors have the ability to withstand high pressure in terms of structural design, mechanical strength, and sealing performance, which can meet the high-pressure working environment of oil pumping in oil wells. The oil pump is installed at the bottom or rear of the linear motor. The linear motor can work in a submerged state or in a state detached from the well fluid. When the well fluid is lifted to the surface, the motor mover and the oil pump plunger bear tensile stress. The force distribution is reasonable and the system is stable. The linear motor working in a state detached from the well fluid means that the linear motor is installed in the oil well with the pump submerged above the fluid surface. This also ensures that the cable is completely free from long-term immersion in the well fluid, thereby extending the cable's service life.

[0030] In addition, the tubular or rod-type oil pumps currently widely used in oil fields can be used in conjunction with this application. Attached Figure Description

[0031] Figure 1 is a structural schematic diagram of an embodiment of the linear motor of this application;

[0032] Figure 2 is a cross-sectional view of an embodiment of the linear motor of this application;

[0033] Figure 3 is a magnified view of a portion of region A in Figure 2;

[0034] Figure 4 is a magnified view of a portion of region B in Figure 2;

[0035] Figure 5 is an assembly diagram of the stator assembly, stator connector and motor head in Figure 1;

[0036] Figure 6 is a cross-sectional view of the stator assembly in Figure 1;

[0037] Figure 7 is a partial structural schematic diagram of the stator assembly and stator connector in Figure 1;

[0038] Figure 8 is a schematic diagram of the end seal in Figure 7;

[0039] Figure 9 is a structural schematic diagram of the stator connector in Figure 1;

[0040] Figure 10 is a schematic diagram of the assembly of the mover assembly and the mover connector;

[0041] Figure 11 is an assembled cross-sectional view of the mover assembly and mover connector in Figure 10;

[0042] Figure 12 is a schematic diagram of the moving part connector in Figure 10;

[0043] Figure 13 is a schematic diagram of the pressure balance assembly in Figure 1;

[0044] Figure 14 is a cross-sectional view of the pressure balancing assembly in Figure 1. The best embodiment of the present invention

[0045] As shown in Figures 1-14, one embodiment of this application provides a linear motor, including:

[0046] Stator module 1 includes multiple stator assemblies 11. Each stator assembly 11 includes an outer tube 111, an inner tube 112, and a coil winding 113. The coil winding 113 and the inner tube 112 are disposed in the outer tube 111. The coil winding 113 is sleeved on the inner tube 112 and sealed between the outer tube 111 and the inner tube 112. Two adjacent outer tubes 111 are sealed together.

[0047] The mover module 2 includes multiple mover components 21 and a mover connecting sleeve 22. Each mover component 21 includes a mover spindle 211 and a permanent magnet 212. The permanent magnet 212 is disposed outside the mover spindle 211, and an oil channel 213 is formed inside the mover spindle 211. The side wall of the mover connecting sleeve 22 is provided with a through opening 221. Two adjacent mover spindles 211 are connected together through the mover connecting sleeve 22, and two adjacent oil channels 213 are connected through the mover connecting sleeve 22.

[0048] The moving part module 2 is set in the stator module 1, and the moving part spindle 211 can slide in the inner liner tube 112, forming an oil passage gap 10 between the moving part module 2 and the inner liner tube 112.

[0049] Specifically, the linear motor provided in this application has a mover module 2 assembled in the stator module 1. The coil winding 113 in the stator module 1 is energized to cooperate with the permanent magnet 212 in the mover module 2, so that the permanent magnet 212 drives the mover spindle 211 to reciprocate in the stator module 1.

[0050] For stator module 1, the outer sleeve 111 serves as an external support and protective component. The thickness of the outer sleeve 111 needs to meet the requirements for pressure resistance and structural strength. The inner liner 112 and coil winding 113 are installed within the outer sleeve 111. The coil winding 113 is located within the sealed space formed between the outer sleeve 111 and the inner liner 112, thus insulating the coil winding 113 from the oil. The inner liner is made of a non-magnetic material to ensure sufficient magnetic force is generated between the coil winding 113 and the permanent magnet 212.

[0051] For the mover module 2, the mover spindle 211 serves as a support and mounting component, with the permanent magnet 212 mounted and fixed to the outside of the mover spindle 211. The interior of the mover spindle 211 has a hollow structure to form an oil channel 213. Thus, when the mover spindle 211 drives the oil pump at the bottom, the oil pumped by the oil pump can be transported upward through the mover spindle 211 to deliver the oil to the ground.

[0052] During the operation of the oil pump, the mover spindle 211 provides tension to the oil pump, enabling it to pump oil into the oil passage 213. The mover spindle 211 can provide a large tension, thus meeting the requirements of high-power oil pumps.

[0053] The oil flowing in the oil passage 213 inside the mover spindle 211 can also flow into the oil passage gap 10 through the through port 221. Furthermore, during use, the oil can flow between the oil passage gap 10 and the oil passage 213.

[0054] During use, the oil in the oil passage gap 10 can also exchange heat with the inner liner tube 112 to remove the heat generated by the coil winding 113 in the corresponding part, thereby improving the reliability of the linear motor.

[0055] The flow cross-sectional area of ​​the oil passage 213 is much larger than that of the oil passage gap 10. During use, the oil flows between the oil passage gap 10 and the oil passage 213, which can improve the smooth operation of the mover assembly 21 and effectively reduce the internal pressure.

[0056] During the downward stroke of the mover spindle 211, the mover assembly 21 drives the plunger of the pump used in this application to move downward, squeezing the oil in the lower part of the pump barrel into the upper part of the pump barrel, preparing for the next pumping stroke. At this time, the oil in the lower buffer tubing 3 flows upward relative to the mover spindle 211 in the oil passage 213; the oil flows upward relative to the inner liner tube 112 in the oil passage gap 10. The flow direction of the oil conforms to the thermodynamic principle. As the upward-flowing oil passes through the linear motor, it fully absorbs the heat generated by the linear motor during operation and carries the heat to the front oil pipe of the motor head 13. In the next pumping stroke, it is continued to be pushed towards the wellhead.

[0057] Furthermore, during the upward stroke of the mover spindle 211, the mover assembly 21 drives the pump plunger upward, lifting the oil in the upper part of the pump plunger and the pump barrel into the lower buffer tubing 3. Simultaneously, the front part of the upward-moving mover assembly 21, when entering the tubing space in front of the motor head 13, pushes the oil in the tubing space towards the wellhead. Because the diameter of the mover assembly 21 is slightly larger than the diameter of the pump plunger, a small amount of oil flows downward relative to the mover spindle 211 in the oil passage 213; a small amount of oil flows downward relative to the inner liner tube 112 in the oil passage gap 10, flowing into the lower buffer tubing 3. The volume of this downward-flowing oil offsets the volume difference between the mover assembly 21 and the pump plunger in the same stroke. Therefore, during the upward stroke, the force on the mover assembly 21 is only the resistance of the upward movement of the pump plunger.

[0058] As described above, the linear motor actuator assembly 21 drives the lower oil pump plunger to continuously pump oil from deep within the oil layer to the surface wellhead in a regular upward and downward reciprocating motion, thus achieving a complete and efficient oil production process. Because the pumped oil fully absorbs the heat of the linear motor, the oil temperature is higher than that of conventional oil production methods, and waxing and freezing will not occur in the oil pipe.

[0059] In one embodiment of this application, the stator assembly 11 further includes two end seals 114, each end seal 114 having a first mounting through hole 1141; the end seals 114 are sealed and inserted into the corresponding openings of the outer sleeve 111, and the end seals of the inner liner 112 are sealed and inserted into the first mounting through hole 1141; the coil winding 113 is located between the two end seals 114, and the mover spindle 211 passes through the first mounting through hole 1141.

[0060] Specifically, in order to facilitate the sealed installation of the coil winding 113 in the stator assembly 11, end seals 114 are provided at both ends of the stator assembly 11. The end seals 114 can seal and connect the outer sleeve 111 and the inner liner 112 at the corresponding end positions, thereby enabling the coil winding 113 to be sealed and assembled between the outer sleeve 111 and the inner liner 112.

[0061] The sealing method between the end seal 114 and the outer sleeve 111 and the inner liner 112 can be welding or adding a sealing ring, and there are no restrictions on this.

[0062] Furthermore, the stator module 1 also includes a stator connector 12, which is provided with a second mounting through hole 121; two adjacent stator assemblies 11 are sealed and fixed together by the stator connector 12, and the stator connector 12 is sealed and connected with the end seal 114 at the corresponding end of the stator assembly 11, and the mover spindle 211 passes through the second mounting through hole 121.

[0063] Specifically, for two adjacent stator assemblies 11, in order to facilitate and quickly connect them, the two adjacent stator assemblies 11 are connected and fixed by stator connectors 12. The stator connectors 12 can be connected to the end seals 114 at the corresponding ends of the stator assemblies 11 by means of bolts or the like.

[0064] Furthermore, to facilitate power supply to each coil winding 113 via cables, a first wiring hole 1142 is provided on the end seal 114, and a second wiring hole 122 is provided on the stator connector 12; for the end seal 114 and stator connector 12 connected together, the first wiring hole 1142 communicates with the second wiring hole 122; the cables connected to the coil windings 113 pass through the first wiring hole 1142 and the second wiring hole 122; the stator module 1 also includes a motor head 13 and an external terminal 14, the motor head 13 is also provided with a third mounting through hole, and a wiring channel 131 is also provided on the motor head 13, the external terminal 14 is sealed in the wiring channel 131; the motor head 13 is connected to the stator assembly 11 at the top, and the third mounting through hole is configured to allow the rotor spindle 211 to pass through; the cables connected to the coil windings 113 also extend into the wiring channel 131 and connect to the external terminal 14.

[0065] Specifically, to supply power to the coil windings 113 in stator module 1, an external power source is connected to the coil windings 113 in different stator assemblies 11 via cables. Since stator module 1 is relatively long, a motor head 13 is provided on the topmost stator assembly 11 for easy cable routing. The motor head 13 has external terminals 14 for connection to the external power supply. Inside stator module 1, cables extend into wiring channels 131 and connect to the external terminals 14. Thus, between adjacent stator assemblies 11, cables can be routed via the first wiring hole 1142 and the second wiring hole 122, while the top motor head 13 can be powered through the external terminals 14 and electrically connected to the cables in the wiring channels 131.

[0066] In one embodiment, in order to facilitate the positioning of the coil winding 113 in the stator assembly 11 and facilitate the wiring inside the stator assembly 11, a first keyway 1143 is provided on the inner end face of the end seal 114, and a second keyway 1131 is provided on the stator core of the coil winding 113. The first keyway 1143 and the second keyway 1131 are connected. A positioning key (not shown) is provided in the second keyway 1131, and the end of the positioning key is inserted into the first keyway 1143.

[0067] Specifically, inside the stator assembly 11, the cables are led through the first wiring hole 1142 of the end seal 114, and the cables need to be precisely connected to the sequentially stacked coil windings 113. Therefore, the sequentially stacked coil windings 113 need to be accurately positioned. This is achieved by providing a second keyway 1131 on the stator core of the coil windings 113, using positioning keys to accurately position the multiple coil windings 113. Simultaneously, the end of the positioning key is inserted into the first keyway 1143 of the end seal 114, ensuring high precision in the relative position of the end seal 114 and the coil windings 113, thus facilitating accurate cable routing during assembly.

[0068] In another embodiment of this application, the stator module 1 further includes: a pressure balancing assembly 15, which includes an outer protective tube 151 and a hydraulic pressure sensing component 152. The hydraulic pressure sensing component 152 is disposed inside the outer protective tube 151. A first pressure balancing cavity 153 is formed inside the hydraulic pressure sensing component 152, and the first pressure balancing cavity 153 is configured to be filled with electrical insulating oil. The hydraulic pressure sensing component 152 is configured to deform under the hydraulic pressure inside the outer protective tube 151 to adjust the pressure inside the first pressure balancing cavity 153. A second pressure balancing cavity 115 is formed between the outer sleeve 111 and the inner liner 112, and the second pressure balancing cavity 115 is configured to be filled with electrical insulating oil. The first pressure balancing cavity 153 and the second pressure balancing cavity 115 are connected.

[0069] Specifically, in order to reduce the overall outer perimeter size of the linear motor, the outer sleeve 111 needs to be made of a thicker material to meet the structural strength requirements, while the inner liner 112 should be as thin as possible to reduce the overall outer perimeter size.

[0070] However, due to the working conditions at the oil extraction site, the linear motor needs to descend to a relatively deep formation. Affected by the bottom oil pressure, the inner liner 112 needs to withstand the oil pressure within the oil passage gap 10. The thinner inner liner 112 may break due to its lower structural strength. By adding the pressure balancing assembly 15, the first pressure balancing chamber 153 formed by the pressure balancing assembly 15 is connected to the adjacent second pressure balancing chamber 115, and the two adjacent second pressure balancing chambers 115 are also interconnected. Under the action of the internal electrical insulating oil, the pressure in the first pressure balancing chamber 153 can be basically the same as the pressure in the different second pressure balancing chambers 115.

[0071] In this way, during use, the oil pressure sensing component 152 will undergo corresponding deformation under the pressure of the oil in the outer protective tube 151, thereby making the pressure of the electrical insulating oil in the first pressure balancing chamber 153 basically the same as the pressure of the oil in the outer sheath. In this way, the pressure of the electrical insulating oil in the different second pressure balancing chambers 115 can be similar to the oil pressure in the oil passage gap 10, so that the structural strength of the thinner inner liner tube 112 itself can meet the requirements of the pressure difference on both sides, improving the safety and reliability of the linear motor and meeting the design requirements of miniaturization of the outer peripheral size of the linear motor.

[0072] Specifically, the hydraulic pressure sensing component 152 can be a pressure capsule filled with electrical insulating oil, which is attached to the inner wall of the outer protective tube 151 and located on the outside of the mover assembly 21. Alternatively, the hydraulic pressure sensing component 152 includes a support tube and an elastic tube, the two ends of which are sealed together to form a first pressure balancing chamber 153. The hydraulic pressure sensing component 152 is fitted onto the outside of the mover assembly 21, and the elastic tube deforms under the pressure of the oil on the outside to keep the pressure difference between the second pressure balancing chamber 115 and the oil on the outside within a small range. Specific structural forms of the hydraulic pressure sensing component 152 are not limited or elaborated upon here.

[0073] In one embodiment, the pressure balancing assembly 15 is disposed between two adjacent stator assemblies 11, and the rotor spindle 211 of at least one rotor assembly 21 is inserted into the outer sleeve 111. In this case, two adjacent second pressure balancing cavities 115 are interconnected, and the first pressure balancing cavity 153 is interconnected with the second pressure balancing cavity 115.

[0074] Alternatively, the pressure balancing assembly 15 is disposed on the stator assembly 11 at the lower end of the stator module 1, and the rotor spindle 211 of at least one rotor assembly 21 is inserted into the outer sleeve 111. In this case, two adjacent second pressure balancing cavities 115 are interconnected, and the first pressure balancing cavity 153 is interconnected with the second pressure balancing cavity 115 in the bottom rotor assembly 21.

[0075] Specifically, to facilitate cable wiring and installation, we will take the example of setting the pressure balancing component 15 on the bottom stator component 11.

[0076] During use, after the linear motor is placed in the oil well, the pressure balancing component 15 is arranged adjacent to the bottom oil pump. The oil pumped by the oil pump will first flow into the pressure balancing component 15 and then flow through each stator component 11 in sequence. The oil pressure sensing component 152 adjusts the internal electrical insulating oil pressure according to the external oil pressure to ensure the reliable operation of the linear motor.

[0077] Furthermore, the stator assembly 11 also includes two end seals 114, each end seal 114 having a first mounting through hole 1141. The end seals 114 are sealed and inserted into the corresponding openings of the outer sleeve 111, and the end seals of the inner liner 112 are sealed and inserted into the first mounting through hole 1141. The outer sleeve 111 and the inner liner 112 form a second pressure balance cavity 115 between the two end seals 114. The coil winding 113 is located between the two end seals 114, and the mover spindle 211 passes through the first mounting through hole 1141.

[0078] Specifically, the outer sleeve 111 and inner liner 112 in the stator assembly 11 are sealed together by the end seal 114 to form the second pressure balance chamber 115. In order to achieve mutual communication between the second pressure balance chambers 115, a first pressure communication hole 1144 is provided on the end seal, and the first pressure communication hole 1144 communicates with the second pressure balance chamber 115.

[0079] Specifically, the electrical insulating oil in the second pressure balancing chamber 115 can enter and exit through the first pressure communication hole 1144, so that the electrical insulating oil can be used to balance the pressure in the second pressure balancing chamber 115 at different locations.

[0080] In the two connected stator assemblies 11, the first pressure communication hole 1144 in one stator assembly 11 is connected to the first pressure communication hole 1144 of the adjacent stator assembly 11. In addition, for the stator assembly 11 adjacent to the pressure balancing assembly 15, the stator assembly 11 is connected to the first pressure balancing cavity 153 of the pressure balancing assembly 15 through the first pressure communication hole 1144.

[0081] In addition, regarding the first keyway 1143 arranged on the end seal 114, the first keyway 1143 extends on the end face of the end seal 114, one end of the first keyway 1143 extends to the first mounting through hole 1141 and communicates with the first mounting through hole 1141, and the other end of the first keyway 1143 extends to the outer side wall of the end seal 114. Meanwhile, the first pressure communication hole 1144 is located in the first keyway 1143.

[0082] In this way, after assembly, the electrical insulating oil in the first pressure balancing chamber can enter and exit the first pressure communication hole 1144 through the horizontally arranged first keyway 1143, so as to ensure the smooth flow of the internal electrical insulating oil between different pressure balancing chambers.

[0083] Furthermore, the stator module 1 also includes a stator connector 12, which is provided with a second mounting through hole 121 and a second pressure communication hole 123. Two adjacent stator assemblies 11 are sealed and fixed together by the stator connector 12. The stator connector 12 is sealed and connected to the end seals 114 at the corresponding ends of the stator assemblies 11. The mover spindle 211 passes through the second mounting through hole 121. For the end seals 114 and the stator connector 12 connected together, the first pressure communication hole 1144 communicates with the second pressure communication hole 123.

[0084] Specifically, two adjacent stator assemblies 11 are connected and fixed together by stator connectors 12. The specific details of how stator connectors 12 connect the two stator assemblies 11 together will not be elaborated here.

[0085] The stator connector 12 is provided with a second pressure communication hole 123. For two adjacent stator assemblies 11, the stator connector 12 is connected to the corresponding end seal 114, and the first pressure communication holes 1144 of the two end seals 114 are connected through the second pressure communication hole 123 of the stator connector 12.

[0086] Furthermore, the stator module 1 also includes a motor head 13 and an external terminal block 14. The motor head 13 is provided with a third mounting through hole, an oil injection hole 132, and a wiring channel 131. The oil injection hole 132 and the wiring channel 131 are arranged outside the third mounting through hole. The external terminal block 14 is sealed in the wiring channel 131. The motor head 13 is connected to the stator assembly 11 at the top. The third mounting through hole is configured to allow the rotor spindle 211 to pass through. The cable connected to the coil winding 113 also extends into the wiring channel 131 and connects to the external terminal block 14. The oil injection hole 132 is connected to the adjacent second pressure balance chamber 115.

[0087] Specifically, the motor head 13 is fixedly mounted on the topmost stator assembly 11, and the stator assembly 11 can be sealed and fixedly connected to the motor head 13 through the stator connector 12. For the specific method of connecting the motor head 13 and the external wiring terminal 14 to the coil winding 113 via cables, please refer to the above description, and it will not be repeated here.

[0088] The motor head 13 is provided with an oil injection hole 132. During the assembly process, electrical insulating oil can be injected into the second pressure balance chamber 115 through the oil injection hole 132 so that the second pressure balance chamber 115 and the first pressure balance chamber 153 are filled with electrical insulating oil.

[0089] In another embodiment of this application, the linear motor further includes an upper buffer oil pipe and / or a lower buffer oil pipe 3.

[0090] The upper buffer oil pipe is located at the top of the stator module 1, and the lower buffer oil pipe is located at the bottom of the stator module 1; the upper buffer oil pipe is configured to communicate with the upper moving mandrel 211, and the lower buffer oil pipe 3 is configured to communicate with the lower moving mandrel 211.

[0091] Specifically, for the lower buffer oil pipe 3, during use, on the one hand, after the multiple moving parts 21 at the bottom move out from the bottom stator part 11, they continue to be protected by the lower buffer oil pipe; on the other hand, during the stroke of the moving parts 21, the oil pumped by the oil pump enters the lower buffer oil pipe to ensure that the oil can be pumped out smoothly and efficiently.

[0092] Similarly, for the upper buffer oil pipe, during use, on the one hand, after the multiple moving parts 21 at the top are removed from the topmost stator part 11, they can continue to be protected by the upper buffer oil pipe. On the other hand, during the up and down stroke of the moving parts 21, the upper buffer oil pipe is used to buffer the oil.

[0093] In another embodiment of this application, in order to improve the connection reliability between the mover assembly 21 and the bottom oil pump, the mover module 2 further includes a lower buffer connection assembly 23.

[0094] The lower buffer connection assembly 23 includes two lower mounting seats 231 and a lower spring 232. The lower spring 232 is connected between the two lower mounting seats 231. The upper lower mounting seat 231 is connected to the bottom moving spindle 211, and the lower lower mounting seat 231 is configured to be connected to the oil pump.

[0095] Specifically, the mover spindle 211 of the bottommost mover assembly 21 needs to be connected to the oil pump. The mover spindle 211 and the oil pump are connected and fixed through the lower buffer connection assembly 23. During use, the lower spring 232 can undergo elastic deformation according to the force, thereby buffering the impact force generated on the oil pump by the mover assembly 21 during the switching of the upper and lower strokes, so as to improve the reliability of use.

[0096] In another embodiment of this application, an oil extraction device is also provided, including an oil pump and the aforementioned linear motor. The linear motor is arranged vertically, and the oil pump is arranged below the linear motor. The mover spindle 211 of the mover assembly 21 located at the bottom of the linear motor is connected to the oil pump.

[0097] Specifically, the oil extraction equipment includes an oil pump and the linear motor in the above embodiment. The linear motor is arranged vertically and located above the oil pump when in use. In this way, the linear motor applies a pulling force to the plunger of the oil pump to drive the oil pump to pump oil.

[0098] Since the linear motor is positioned above the oil pump, in actual use, it is only necessary to ensure that the submersion depth of the oil pump meets the requirements for oil extraction. The linear motor can be partially located below the liquid surface or positioned above the liquid surface.

[0099] During the oil pumping process, the oil pressure sensing component 152 is immersed in the well fluid pumped out by the oil pump. Through the transmission of electrical insulating oil, the internal pressure of the linear motor can be dynamically balanced with the pressure in the well fluid channel of the oil pumping unit in real time. The pressure difference is small or there is no pressure difference. The sealing effect of each seal is safe and reliable. The linear motor is not affected by the well fluid pressure and can achieve long-term stable operation.

[0100] In another embodiment of this application, an oil extraction device is also provided, including an oil pump and the aforementioned linear motor. The linear motor is arranged laterally, and the oil pump is arranged at the rear end of the linear motor. The mover spindle 211 of the mover assembly 21 located at the rear end of the linear motor is connected to the oil pump.

[0101] Specifically, the oil production equipment includes a pumping unit and the linear motor described in the above embodiment. The linear motor is arranged horizontally in the oil well during use, so that the pumping unit can be arranged behind the linear motor. In this way, the linear motor drives the plunger of the pumping unit to pump oil.

Claims

1. A linear motor, characterized in that, include: A stator module includes multiple stator components. Each stator component includes an outer tube, an inner tube, and a coil winding. The coil winding and the inner tube are disposed in the outer tube. The coil winding is sleeved on the inner tube and sealed between the outer tube and the inner tube. Two adjacent outer tubes are sealed together. A mover module includes multiple mover components and a mover connecting sleeve. Each mover component includes a mover spindle and a permanent magnet. The permanent magnet is disposed outside the mover spindle, and an oil channel is formed inside the mover spindle. The side wall of the mover connecting sleeve is provided with a through opening. Two adjacent mover spindles are connected together through the mover connecting sleeve, and two adjacent oil channels are connected through the mover connecting sleeve. The moving part module is slidably disposed in the stator module and inserted into the inner liner tube.

2. The linear motor according to claim 1, characterized in that, The stator assembly also includes two end seals, each end seal having a first mounting through hole; The end seal is inserted into the corresponding opening of the outer sleeve, and the end seal of the inner liner is inserted into the first mounting through hole. The coil winding is located between the two end seals, and the moving mandrel passes through the first mounting through hole.

3. The linear motor according to claim 2, characterized in that, The stator module also includes a stator connector, which is provided with a second mounting through hole; Two adjacent stator assemblies are sealed and fixed together by the stator connector, the stator connector is sealed and connected to the end seal of the corresponding end of the stator assembly, and the mover spindle passes through the second mounting through hole.

4. The linear motor according to claim 3, characterized in that, The end seal is provided with a first wiring hole, and the stator connector is provided with a second wiring hole; For the end seal and the stator connector connected together, the first wiring hole communicates with the second wiring hole; The cable connected to the coil winding passes through the first wiring hole and the second wiring hole.

5. The linear motor according to claim 1, characterized in that, The stator module also includes: A pressure balancing assembly, comprising an outer protective tube and an oil pressure sensing component, wherein the oil pressure sensing component is disposed within the outer protective tube; The hydraulic pressure sensing component has a first pressure balancing chamber formed inside, and the first pressure balancing chamber is configured to be filled with electrical insulating oil; the hydraulic pressure sensing component is configured to deform under the hydraulic pressure inside the outer protective tube to adjust the pressure inside the first pressure balancing chamber. A second pressure balancing cavity is formed between the outer tube and the inner tube, and the second pressure balancing cavity is configured to be filled with electrical insulating oil. The first pressure balancing chamber and the second pressure balancing chamber are connected.

6. The linear motor according to claim 5, characterized in that, The pressure balancing assembly is disposed between two adjacent stator assemblies, and the rotor spindle of at least one rotor assembly is inserted into the outer sleeve. Alternatively, the pressure balancing assembly is disposed on the stator assembly located at the lower end of the stator module, and the rotor mandrel of at least one of the rotor assemblies is inserted into the outer sleeve.

7. The linear motor according to claim 5, characterized in that, The first pressure balancing chamber is connected to the second pressure balancing chamber. Alternatively, two adjacent second pressure balancing cavities are interconnected, and the first pressure balancing cavity is connected to the second pressure balancing cavity in the bottom moving part assembly.

8. The linear motor according to any one of claims 5-7, characterized in that, The stator assembly also includes two end seals, each end seal having a first mounting through hole; The end seal is inserted into the corresponding opening of the outer sleeve, and the end seal of the inner liner is inserted into the first mounting through hole. The outer tube and the inner liner form a second pressure balance cavity between the two end seals, the coil winding is located between the two end seals, and the moving mandrel passes through the first mounting through hole.

9. The linear motor according to claim 8, characterized in that, The end seal is also provided with a first pressure communication hole, which is connected to the second pressure balance cavity. In the two stator assemblies connected together, the first pressure communication hole in one stator assembly communicates with the adjacent first pressure communication hole in the other stator assembly.

10. The linear motor according to claim 9, characterized in that, The stator module further includes a stator connector, which is provided with a second mounting through hole and a second pressure communication hole. Two adjacent stator assemblies are sealed and fixed together by the stator connector, the stator connector is sealed and connected to the end seal of the corresponding end of the stator assembly, and the mover spindle passes through the second mounting through hole; For the end seal and the stator connector connected together, the first pressure communication hole communicates with the second pressure communication hole.

11. A linear motor according to any one of claims 1-7, characterized in that, The linear motor further includes an upper buffer oil pipe and / or a lower buffer oil pipe; the upper buffer oil pipe is disposed at the top of the stator module, and the lower buffer oil pipe is disposed at the bottom of the stator module; the upper buffer oil pipe is configured to communicate with the upper moving mandrel, and the lower buffer oil pipe is configured to communicate with the lower moving mandrel; And / or, the mover module further includes a lower buffer connection assembly, the lower buffer connection assembly including two lower mounting seats and a lower spring, the lower spring being connected between the two lower mounting seats, the upper lower mounting seat being connected to the lower mover spindle, and the lower lower mounting seat being configured to be connected to an oil pump.

12. An oil extraction device, comprising an oil pump, characterized in that, It also includes a linear motor as claimed in any one of claims 1-11, characterized in that the linear motor is arranged vertically, the oil pump is arranged below the linear motor, and the mover spindle of the mover assembly located at the bottom of the linear motor is connected to the oil pump. Alternatively, the linear motor is arranged laterally, the oil pump is arranged at the rear end of the linear motor, and the mover spindle of the mover assembly located at the rear end of the linear motor is connected to the oil pump.

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