Submersible electric pump protector oil injection device and submersible electric pump protector

Abstract

This invention relates to the field of oil extraction equipment, and discloses an oil injection device for a submersible electric pump protector and a submersible electric pump protector. The oil injection device includes a first connector and a second connector. The first connector has a side oil storage chamber located to the side of the central axis. The side oil storage chamber has an oil delivery channel extending to a first end of the first connector and has a switch valve inside that controls the opening and closing of the oil delivery channel. The switch valve includes an actuator extending beyond the first end. When the actuator is not subjected to external force, the switch valve closes the oil delivery channel. The inner wall of the second connector body has a radially protruding stop. During the assembly of the second connector and the first connector, the stop abuts against the actuator and causes the actuator to move axially relative to the side oil storage chamber to open the oil delivery channel. This invention, by setting an independently closable oil injection device at the bottom of the protector, allows the device to be pre-filled with oil before being transported to the site for direct installation, eliminating the need for on-site oil injection, saving a significant amount of oil injection time, improving assembly efficiency, and reducing environmental pollution.

Description

Technical Field

[0001] This invention relates to the field of oil extraction equipment, specifically to an oil injection device for a submersible electric pump protector and a submersible electric pump protector. Background Technology

[0002] As a rodless oil production device, the submersible electric pump (Submarine Pump) offers advantages over other oil production equipment, including higher head, faster production, easier operation, higher efficiency, and more convenient management. Its usage has been increasing in recent years. The Submarine Pump Protector is a crucial component of the Submarine Pump production system, serving to isolate the well fluid and provide lubrication for components such as the reducer, motor, and bearings. During the operation, well tripping, and unit installation of the Submarine Pump production system, the oil in the equipment will expand or contract due to changes in ambient temperature. To ensure sufficient insulation and lubrication for each component, oil needs to be replenished continuously to guarantee normal operation after the next startup. During unit operation, the unit will continuously repeat the startup-shutdown-start-up process due to changes in the grid power supply, production volume, and load. During this process, the protector, through its "breathing" function, supports the expansion and contraction of the oil within the chambers of each component.

[0003] Traditional oil well protectors have an open connection between their internal cavity and the submersible motor (SMP), requiring oil filling to be completed during on-site operations. In offshore and onshore oilfield development, with numerous and dispersed wells, traditional protector installation necessitates significant time for oil filling, greatly increasing well workover costs and time. Furthermore, the harsh on-site environment can lead to incomplete oil filling or leaking seals, causing premature protector failure and severely impacting the SMP's lifespan. Additionally, oil filling on offshore platforms often results in the spillage of insulating oil, causing environmental pollution.

[0004] Therefore, it is necessary to design a new oil injection structure for the submersible electric pump protector to solve the problems of low efficiency and poor oil injection effect caused by the installation and oil injection of traditional protectors. Summary of the Invention

[0005] The main objective of this invention is to provide an oil injection device for a submersible electric pump protector and a submersible electric pump protector.

[0006] According to one aspect of the present invention, a submersible electric pump protector oil injection device is provided, the device comprising:

[0007] A first connector has a central axis and a side oil reservoir located to the side of the central axis. The side oil reservoir has an oil delivery channel that opens to a first end of the first connector. A switching valve for controlling the opening and closing of the oil delivery channel is provided in the side oil reservoir. The switching valve includes an actuator extending beyond the first end. When the actuator is not subjected to external force, the switching valve closes the oil delivery channel.

[0008] The second connector has a cylindrical body and is coaxially arranged with the first connector. The inner wall of the body is provided with a radially protruding stop. During the assembly of the second connector and the first connector, the stop abuts against the actuator and causes the actuator to move axially relative to the side oil storage cavity to open the oil delivery channel.

[0009] According to one embodiment of the present invention, the first connector further includes a second end spaced axially from the first end, and the side oil storage cavity is provided with a contraction section, a transition section and a straight section in sequence in the direction from the first end to the second end. The transition section is conical in shape, and the diameter of the cone gradually increases in the direction from the contraction section to the straight section.

[0010] According to one embodiment of the present invention, the switching valve further includes:

[0011] A support member, which is fixedly installed to the straight section of the side oil storage cavity and has a flow hole;

[0012] A sealing element having a sealing portion whose shape is adapted to the shape of the transition section, such that the oil delivery channel is closed when the two come into contact.

[0013] An elastic element is located between the support and the sealing element and applies pressure to the sealing element;

[0014] The actuator is connected to the sealing member and extends through the contraction section to the outside of the first connector.

[0015] According to one embodiment of the present invention, the switching valve further includes:

[0016] A flexible seal is fitted onto the sealing portion.

[0017] According to one embodiment of the present invention, the sealing member further has a base located between the elastic member and the sealing portion, the base being in clearance fit with the straight section.

[0018] According to one embodiment of the present invention, the device further includes a protective cap that is detachably connected to the actuator and configured to prevent the switching valve from opening.

[0019] According to one embodiment of the present invention, the protective cap has a top wall and a circumferential wall, the inner surface of the circumferential wall is provided with a protrusion protruding toward the center, the actuator is a rod-shaped member with a guide groove on its outer surface, the guide groove includes a communicating axial section and a circumferential section, the axial section extends to the end of the actuator, the circumferential section is spaced apart from the end of the actuator by a predetermined distance, the protrusion of the protective cap can slide from the axial section into the guide groove and rotate along the circumferential section, preventing the actuator from moving axially relative to the side oil reservoir.

[0020] According to one embodiment of the present invention, the protective cap includes:

[0021] The outer casing includes a bottom wall, side walls, and an inner cavity formed by the bottom wall and side walls, wherein the bottom wall is provided with an insertion hole;

[0022] A movable box is disposed within the inner cavity. The movable box contains a movable partition with a through hole aligned with the insertion hole. The partition divides the movable box into an upper and a lower part. The upper part has an elastic element, and the lower part has a peripheral wall and a lower wall. The peripheral wall is a tapered shape that gradually tapers from top to bottom. The lower wall has an opening aligned with the insertion hole and the through hole. Multiple ball bearings are disposed in the lower part.

[0023] The actuator has a constricted section and a tapered end. The diameter of the constricted section is smaller than the diameter of the portions on both sides of the constricted section. The actuator can be inserted into the insertion hole, the opening, and the through hole. The constricted section engages with the ball bearing to prevent the actuator from detaching from the protective cap.

[0024] According to one embodiment of the present invention, the stop member includes:

[0025] A pair of positioning rings fixedly installed on the inner wall of the main body and spaced apart;

[0026] A retaining ring is held between a pair of positioning rings, the retaining ring protruding radially inward and capable of abutting against the actuator.

[0027] According to one embodiment of the present invention, the device further includes a central oil reservoir configured to accommodate a protector shaft, the central oil reservoir extending along the central axis and communicating with the side oil reservoir, the central oil reservoir having a closure at the first end for closing the gap between the central oil reservoir and the protector shaft.

[0028] According to one embodiment of the present invention, a main flow channel is provided between the central oil storage chamber and the side oil storage chamber, and the main flow channel is in the shape of an hourglass that narrows in the middle and expands on both sides.

[0029] According to one embodiment of the present invention, a drainage branch is further provided between the central oil storage chamber and the side oil storage chamber. The drainage branch is connected to the main flow channel. One end of the drainage branch is connected to the middle constriction part of the main flow channel, and the other end is connected to the side oil storage chamber.

[0030] According to another aspect of the present invention, a submersible electric pump protector is provided, the protector comprising a submersible electric pump protector oil injection device according to any of the preceding claims, wherein a first connector of the submersible electric pump protector oil injection device serves as a lower connector of the submersible electric pump protector, a side oil reservoir of the first connector communicates with an oil reservoir located above the submersible electric pump protector oil injection device, and a second connector is connected to a motor shaft.

[0031] In the technical solution of this invention, an independently sealable oil injection device is set at the bottom of the protector. After the device is pre-filled with oil, it can be transported to the site for direct connection without the need for on-site oil injection, saving a lot of oil injection time, improving assembly efficiency, and reducing the risk of environmental pollution. The separate design and assembly of the first connector switch valve and the second connector stop component realize the independent sealing of the oil supply channel before installation and the automatic opening after installation. This ensures that the oil injection device will not leak oil before installation and also realizes the function of replenishing motor oil required by the protector. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of the overall structure of the oil injection device for the submersible electric pump protector according to an embodiment of the present invention is shown.

[0034] Figure 2 A schematic diagram of a first connector according to an embodiment of the present invention is shown;

[0035] Figure 3 A schematic diagram of a second connector according to an embodiment of the present invention is shown;

[0036] Figure 4 A schematic diagram of a protective cap according to a first embodiment of the present invention is shown;

[0037] Figure 5 A schematic diagram of a protective cap according to a second embodiment of the present invention is shown;

[0038] Figure 6 A schematic diagram of a flow channel according to an embodiment of the present invention is shown.

[0039] List of reference numerals in the attached diagram:

[0040] 100-First connector; 110-First connector base; 111-Central oil reservoir; 112-Side oil reservoir; 113-First end; 114-Second end; 115-Main flow channel; 116-Drainage branch; 120-Switch valve; 121-Support member; 122-Sealing member; 122a-Sealing member base; 122b-Sealing member sealing part; 123-Elastic member; 124-Actuator; 124A-Actuator (variant with guide groove); 124a-Guide groove; 124a1-Axial section of guide groove; 124a2-Circumferential section of guide groove; 124B-Actuator (variant with necking section); 125-Flexible seal; 130-Sealing member; 200-Second connector; 210-Second... Connector body; 220-Stop; 221-Positioning ring; 222-Retaining ring; 300-Protective cap; 300A-First variant protective cap; 310A-Top wall of protective cap; 320A-Circumferential wall of protective cap; 330A-Protrusion; 300B-Second variant protective cap; 310B-Outer shell; 311B-Bottom wall of outer shell; 312B-Side wall of outer shell; 313B-Top wall of outer shell; 314B-Inner cavity of outer shell; 320B-Moving box; 321B-Partition plate; 322B-Upper part of moving box; 323B-Lower part of moving box; 323B1-Lower lower wall; 323B2-Lower circumferential wall; 324B-Elastic element; 325B-Ball; A-Central axis; S1-Protector shaft; S2-Motor shaft. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0042] The terms "comprising" and "having," and any variations thereof, used in the specification and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, or accompanying drawings of this invention are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0043] In the description of this invention and the above-described drawings, when an element is referred to as "fixed to," "mounted to," "set on," or "connected to" another element, it can be located directly or indirectly on that other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to that other element.

[0044] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0045] refer to Figures 1 to 3 This invention proposes an oil filling device for a submersible electric pump protector. The device generally includes a first connector 100 and a second connector 200. The first connector 100 has a central axis A and a side oil reservoir 112 located to the side of the central axis A. The side oil reservoir 112 has an oil delivery channel opening to a first end 113 of the first connector 100. A switching valve 120 for controlling the opening and closing of the oil delivery channel is provided within the side oil reservoir 112. The switching valve 120 includes an actuator 124 extending beyond the first end 113. When the actuator 124 is not subjected to external force, the switching valve 120 closes the oil delivery channel. The second connector 200 has a cylindrical body 210, coaxially arranged with the first connector 100. The inner wall of the body 210 has a radially protruding stop 220. During the assembly of the second connector 200 and the first connector 100, the protruding actuator 124 is inserted into the hollow cavity of the body 210 of the second connector 200. The stop 220 abuts against the actuator 124 to prevent it from being inserted further. When the second connector 200 and the first connector 100 are further tightened, the actuator 124 is abutted by the stop 220 and moves axially relative to the side oil storage cavity 112, thereby opening the oil supply channel so that the oil in the side oil storage cavity 112 can communicate with the oil in the hollow area of ​​the body 210.

[0046] In embodiments of the present invention, an independently sealable oil filling device is provided at the lower part of the protector. After the device is pre-filled with oil, it can be transported to the site for direct connection without the need for on-site oil filling, saving a significant amount of oil filling time, improving assembly efficiency, and reducing the risk of environmental pollution. The separate design and assembly of the first connector 100 (switching valve 120) and the second connector 200 (stop component 220) achieve independent sealing of the oil supply channel before installation and automatic opening after installation. This ensures that the oil filling device does not leak oil before installation and also fulfills the function of replenishing the protector with the required motor oil.

[0047] In some embodiments, such as Figure 1-2As shown, the first connector 100 has a cylindrical base 110, which includes a first end 113 and a second end 114 spaced apart axially. A side oil reservoir 112 extends from the first end 113 to the second end 114. The side oil reservoir 112 is generally cylindrical and may sequentially include a contraction section, a transition section, a straight section, and an expansion section in the direction from the first end 113 to the second end 114. Among the various sections of the side oil reservoir 112, the contraction section has the smallest diameter, which can accommodate and induce the actuator 124. A gap is reserved between the inner wall of the contraction section and the outer surface of the actuator 124, thereby allowing insulating oil to flow in the gap. The transition section is conical in shape, and the diameter of the cone gradually increases from the contraction section to the straight section. It achieves the closure of the oil delivery channel with the switching valve 120 through a shape-fitting mechanism. The straight section has a constant cross-sectional shape at different axial positions, providing support for the switching valve 120 and the necessary stroke space for its switching operation. The expansion section is the main oil storage area of ​​the side oil reservoir 112, which connects to the oil passages / cavities of other parts of the protector. When oil needs to be added to the motor, the oil in the side oil reservoir 112 can flow into the vicinity of the motor shaft S2, while the oil in other parts of the protector can be added to the expansion section of the side oil reservoir 112. When the oil in the hollow area of ​​the main body 210 expands due to heat and needs to be discharged, it first discharges to the side oil reservoir 112 and then through the expansion section to other oil cavities of the protector. Figure 2 In the illustrated embodiment, the diameter of the expansion section of the side oil reservoir 112 is the largest. However, the invention is not limited to this; the diameter of the expansion section can be designed to be larger or smaller than the diameters of other sections, or the same as the diameters of other sections, depending on actual needs.

[0048] In this embodiment of the invention, the integration and optimization of functions are achieved through the reasonable layout of the contraction section, transition section, straight section and expansion section, providing a supporting foundation for the stable opening and closing of the oil circuit, constructing a bidirectional oil flow system, timely meeting the oil replenishment / discharge needs of the motor, and ensuring the safe and stable operation of the motor.

[0049] In some embodiments, such as Figure 2As shown, the switching valve 120 generally includes a support 121, a plugging member 122, an elastic member 123, and an actuator 124. The support 121 is fixedly installed to the straight section of the side oil reservoir 112. For example, the inner wall of the straight section may have internal threads, and the outer wall of the support 121 may have external threads. The two are fixedly assembled by threaded engagement. The central portion of the support 121 has a flow hole that extends through its entire axial dimension, through which the oil stored in the expansion section can flow through the support 121. The plugging member 122 may have a base 122a and a plugging portion 122b, with the plugging portion 122b being closer to the first end 113 than the base 122a. The shape of the plugging portion 122b is adapted to the shape of the transition section, i.e., the plugging portion 122b is also conical, so that the oil passage is closed when the two come into contact. An elastic element 123 is located between the support element 121 and the sealing element 122. The elastic element 123 applies pressure to the sealing element 122, causing the sealing portion 122b to be pressed against the transition section, thereby closing the oil supply passage when no external force is applied. The elastic element 123 can be, for example, a spring. An actuator 124 is connected to the sealing element 122 and extends through the contraction section to the outside of the first connector 100. The actuator 124 can be rod-shaped.

[0050] The base 122a of the sealing element 122 is located between the elastic element 123 and the sealing part 122b. The outer surface of the base 122a is clearance-fitted with the inner wall of the straight section, and the gap between them can serve as a channel for oil flow. One end of the base 122a receives the sealing part 122b, and the other end contacts the elastic element 123, so that the pressure applied by the elastic element 123 can be evenly transmitted to the sealing part 122b through the base 122a, ensuring that the sealing part 122b fits tightly with the transition section and achieves a reliable seal. The clearance fit between the base 122a and the inner wall of the straight section ensures that the base 122a can move stably axially within the straight section, and provides accurate radial positioning for the sealing part 122b by matching the dimensions of the straight section. During the switching process of the switching valve 120, the base 122a can guide the sealing part 122b to quickly align with the transition section. In operation, the coaxiality of the sealing part 122b and the transition section is maintained to ensure that their sealing surfaces are fully in contact, thereby improving the sealing effect. When the switching valve 120 moves axially under the action of the actuator 124, the mating surface between the base 122a and the straight section can effectively constrain the radial degree of freedom of the sealing part 122, preventing it from swinging or tilting during movement.

[0051] In this embodiment of the invention, the sealing part 122b is adapted to the shape of the transition section, and when they abut each other, they form a tight fit, effectively blocking the transmission of oil. Combined with the pressure applied by the elastic element 123, the sealing part 122b is always pressed against the transition section without external force, enhancing the sealing effect, avoiding the risk of oil leakage, and ensuring the sealing performance and safety of the oil injection device in the unassembled state. During assembly, by cooperating with the stop element 220 to apply external force to the actuator 124, the sealing part 122b can be easily driven to overcome the pressure of the elastic element 123, realizing the separation of the sealing part 122b from the transition section, thereby quickly opening the oil delivery channel. The operation is simple and convenient. The components have clear division of labor and cooperate with each other, forming a compact and fully functional overall structure, which not only ensures the reliability of the switching valve 120, but also facilitates maintenance and repair, improving the practicality and durability of the entire oil injection device.

[0052] In some embodiments, such as Figure 2 As shown, the switching valve 120 may also include a flexible seal 125, which may specifically be an O-ring. The O-ring has good elasticity and flexibility, capable of filling the microscopic gaps between the sealing portion 122b and the transition section contact surface, forming multiple sealing barriers. Compared to rigid sealing structures, flexible seals can adapt to minor unevenness or deformation of the contact surface, maintaining reliable sealing performance even with slight machining errors or wear during use, effectively preventing oil leakage and improving the sealing performance and safety of the oil injection device.

[0053] In some embodiments, such as Figure 2 As shown, the first connector 100 also includes a central oil reservoir 111 configured to accommodate the protector shaft S1. The central oil reservoir 111 extends along the central axis A and communicates with the side oil reservoir 112. For example, a sealing structure is provided at the second end 114 of the first connector 100 to block the central oil reservoir 111 and the side oil reservoir 112. This sealing structure has a clearance fit with the base 110 of the first connector 100 (especially in the radial portion between the central oil reservoir 111 and the side oil reservoir 112). The gap between the sealing structure and the base 110 can serve as a communication channel between the central oil reservoir 111 and the side oil reservoir 112. The central oil reservoir 111 can communicate with other oil chambers of the protector. The central oil reservoir 111 is equipped with a sealing element 130 at its first end 113 to seal the gap between the central oil reservoir 111 and the protector shaft S1. Specifically, the sealing element 130 can be a shaft seal, thereby preventing oil leakage from the central oil reservoir 111 when the protector shaft S1 rotates. The shaft seal structure design can achieve both static and dynamic sealing. The designed shaft seal can operate for more than two years at speeds up to 3500 r / min.

[0054] In some embodiments, such as Figure 1 and Figure 3 As shown, the second connector 200 has a cylindrical body 210, one end of which is connected to the first end 113 of the first connector 100, and the other end is connected to the motor shaft S2. The hollow interior of the body 210 can be filled with oil to provide lubrication and cooling for the motor shaft S2. A stop 220 is provided on the inner wall of the body 210 near the end of the first connector 100. Figure 3 As shown, the stop member 220 may include a pair of positioning rings 221 and a retaining ring 222. The pair of positioning rings 221 are fixedly installed on the inner wall of the main body 210 and are spaced apart. The retaining ring 222 is clamped between the pair of positioning rings, and the retaining ring protrudes radially inward and can abut against the actuator 124, causing the switching valve 120 to open.

[0055] During the handling or installation of the oil filling device, operators may accidentally open the oil supply channel by accidentally activating the actuator 124. In other cases, during vehicle transportation, the actuator 124 may shift due to vehicle bumps and vibrations, causing oil leakage. To prevent the switch valve 120 from opening accidentally, in some embodiments, such as... Figure 2 As shown, the oil injection device of the submersible electric pump protector may also include a protective cap 300. The protective cap 300 can be detachably connected to the actuator 124 through a mechanical interface. The protective cap 300 restricts the axial displacement of the actuator 124 through a physical barrier mechanism, ensuring that the switching valve 120 remains closed in the non-operating state.

[0056] Figure 4 A schematic diagram of a first variant protective cap 300A according to a first embodiment of the present invention is shown. The first variant protective cap 300A and the actuator 124 are locked by a rotational snap-fit ​​mechanism. Specifically, as shown... Figure 4 As shown, the first variant protective cap 300A may have a top wall 310A and a circumferential wall 320A, with a protrusion 330A projecting towards the center on the inner surface of the circumferential wall 320A. Correspondingly, the actuator 124A is a rod-shaped member with a guide groove 124a on its outer surface, the guide groove 124a including a communicating axial segment 124a1 and a circumferential segment 124a2. The axial segment 124a1 extends to the end of the actuator 124A, its extension direction being parallel to the axial direction of the actuator 124A. The circumferential segment 124a2 is spaced a predetermined distance from the end of the actuator 124A and extends circumferentially along the actuator 124A. In use, the protrusion 330A of the first variant protective cap 300A is aligned with the end opening of the guide groove 124a, causing the protrusion 330A to slide from the axial segment 124a1 into the guide groove 124a and rotate along the circumferential segment 124a2. The bottom end of the first variant protective cap 300A abuts against the first end 113 of the first connector 100. The mating structure of the protrusion and groove effectively prevents the actuator 124A from moving axially relative to the side oil reservoir. When it is necessary to remove the first variant protective cap 300A, it can be unlocked by reversing the operation sequence.

[0057] Figure 5 A schematic diagram of a second variant protective cap 300B according to a second embodiment of the present invention is shown. Specifically, as Figure 5 As shown, the second variant protective cap 300B may include a housing 310B and a movable box 320B. The housing 310B is generally box-shaped and includes a bottom wall 311B, side walls 312B, a top wall 313B, and an inner cavity 314B enclosed by these walls. The bottom wall 311B has an insertion hole. The movable box 320B is disposed in the inner cavity 314B. The movable box 320B has a vertically movable partition 321B, which is magnetic and has a through hole aligned with the insertion hole. The partition 321B divides the movable box 320B into an upper part 322B and a lower part 323B. The upper part 322B has an elastic element 324B, which may be a spring, that applies a spring force to the partition 321B to cause it to move downward. The lower part 323B of the movable box 320B has a lower wall 323B1 and a peripheral wall 323B2, the peripheral wall 323B2 being a tapered shape that gradually tapers from top to bottom. The lower wall 323B1 has an opening aligned with the insertion hole and the through hole. A plurality of ball bearings 325B (e.g., three ball bearings) are provided in the lower part 323B. Correspondingly, the actuator 124B has a constricted section and a tapered end, the diameter of which is smaller than the diameter of the portions on either side of the constricted section. When the actuator 124B is inserted into the socket, opening, and through hole, the elastic element 324B presses down the partition 321B, causing the ball 325B to move downward and engage with the constricted section of the actuator 124B. The bottom wall 311B of the housing 310B abuts against the first end 113 of the first connector 100. When the actuator 124B tends to disengage from the second variant protective cap 300B, the engagement of the ball 325B with the constricted section causes the actuator 124B to drive the ball 325B to move slightly downward. Since the lower part of the moving box 320B is a constricted cone, the engagement of the ball 325B with the actuator 124B becomes tighter when it moves downward, making it difficult for the actuator 124B to disengage from the second variant protective cap 300B. When the second variant protective cap 300B needs to be removed, another magnetic component attracts the partition 321B from the top wall 313B. The partition 321B overcomes the elastic force of the elastic element 324B and moves upward, allowing the ball bearing 325B to move upward and release the locking action. This structure of the protective cap 300 eliminates the need for complex alignment and positioning, and provides a stronger locking effect.

[0058] When the submersible pump protector is in use, its axis is usually in a vertical or near-vertical position. In this state, the oil flow between the central oil reservoir 111 and the side oil reservoir 112 may be relatively slow. Especially when the motor shaft S2 rotates at a high speed, its high-speed rotation generates heat, and the oil expands due to heat and needs to be discharged from the second connector 200. To accelerate the oil flow rate between the central oil reservoir 111 and the side oil reservoir 112, in some embodiments, such as... Figure 6 As shown, a channel for oil flow can be provided between the central oil storage chamber 111 and the side oil storage chamber 112. In some embodiments, the channel may include a main flow channel 115, which is hourglass-shaped, contracting in the middle and expanding on both sides. Based on the principle of fluid dynamics, when liquid flows through the contracting section of the pipe, the flow velocity increases significantly due to the reduced cross-sectional area of ​​the flow channel, while the pressure decreases. In the expanding section, the flow velocity slows down and the pressure rises. Based on this principle, designing the main flow channel 115 between the central oil storage chamber 111 and the side oil storage chamber 112 as an hourglass-shaped structure with a contracting middle and expanding on both sides can effectively accelerate the oil flow.

[0059] In some embodiments, the channel may further include a diversion branch 116, which is connected to the main flow channel 115. Specifically, one end of the diversion branch 116 is connected to the middle constricted portion of the flow channel 115, and the other end is connected to the side oil storage chamber 112. Since the oil flow velocity is the highest and the pressure is the lowest in the constricted portion, one end of the diversion branch 116 opens into this low-pressure area, and the other end connects to the relatively high-pressure side oil storage chamber 112. The pressure difference between the two locations will accelerate the flow of oil in the side oil storage chamber 112 through the diversion branch 116 to the constricted section, using the low-pressure area generated by the high-speed main flow to draw oil from the side oil storage chamber 112, increasing the power of the oil to flow towards the central oil storage chamber 111.

[0060] The present invention also provides a submersible electric pump protector, which includes the oil injection device for the submersible electric pump protector as described above. (Reference) Figure 1 The first connector 100 of the oil filling device of the submersible electric pump protector can be used as the lower connector of the protector. Its upper end is connected to other components of the protector (such as the protector shaft guard tube, sedimentation chamber, etc.). The side oil reservoir 112 of the first connector 100 communicates with the protector oil reservoir chamber located above it, thereby providing support for the replenishment and discharge of oil in the side oil reservoir 112. The lower part of the protector shaft S1 extends through the central oil reservoir 111. One end of the second connector 200 is connected to the first connector 100, and the other end of the second connector 200 is connected to the motor shaft S2. The protector shaft S1 and the motor shaft S2 can be connected by a key.

[0061] In use, first remove the protective cap 300 from the actuator 124, then bolt the second connector 200 to the motor, and bolt the first connector 100 to the second connector 200. During the connection process, the actuator 124 abuts against the retaining ring 222. Since the retaining ring 222 is fixed inside the second connector 200 by the positioning ring 221, the actuator 124 is pressed against and compresses the elastic element 123, thus separating the sealing part 122b from the transition section and opening the oil supply channel. Because the support 121 has a flow hole, the oil will flow through the flow hole and the oil supply channel under its own gravity, entering the hollow cavity of the second connector 200 to replenish the motor with insulating oil. In addition, when the motor heats up, the oil expands due to heat, enters the side oil storage chamber 112 through the oil supply channel, then enters other oil storage chambers of the protector, and is finally discharged outside the protector, achieving internal and external balance.

[0062] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. An oil injection device for an ESP protector, characterized in that, include: A first connector (100) has a central axis (A) and a side oil reservoir (112) located to the side of the central axis (A). The side oil reservoir (112) has an oil delivery channel opening to a first end (113) of the first connector (100). A switching valve (120) for controlling the opening and closing of the oil delivery channel is provided in the side oil reservoir (112). The switching valve (120) includes an actuator (124) extending beyond the first end (113). When the actuator (124) is not subjected to external force, the switching valve (120) closes the oil supply channel. The first connector (100) also includes a second end (114) axially separated from the first end (113). The side oil storage chamber (112) is provided with a contraction section, a transition section, and a straight section in sequence from the first end (113) to the second end (114). The transition section is conical in shape, and the diameter of the cone gradually increases from the contraction section to the straight section. The switching valve (120) further includes: a support member (121) fixedly installed to the straight section of the side oil reservoir (112) and having a flow passage; a plug (122) having a plug portion (122b) whose shape is adapted to the shape of the transition section, such that the oil passage is closed when the two come into contact; and an elastic member (123) located between the support member (121) and the plug (122) and applying pressure to the plug (122), wherein the actuator (124) is connected to the plug (122) and extends through the contraction section to the outside of the first connector (100); The second connector (200) has a cylindrical body (210) with a radially protruding stop (220) on the inner wall of the body (210). During the assembly of the second connector (200) and the first connector (100), the stop (220) abuts against the actuator (124) and causes the actuator (124) to move axially relative to the side oil reservoir (112) to open the oil delivery channel. The device also includes a protective cap (300) that is detachably connected to the actuator (124) and configured to prevent the switching valve (120) from opening. The protective cap (300) has a top wall (310A) and a circumferential wall (320A). The inner surface of the circumferential wall (320A) is provided with a protrusion (330A) protruding towards the center. The actuator (124) is a rod-shaped member with a guide groove (124a) on its outer surface. The guide groove (124a) includes a communicating axial section (124a1) and a circumferential section (124a2). The axial section (124a1) extends to the end of the actuator (124), and the circumferential section (124a2) is spaced apart from the end of the actuator (124) by a predetermined distance. The protrusion (330A) of the protective cap (300) can slide from the axial section (124a1) into the guide groove (124a) and rotate along the circumferential section (124a2), preventing the actuator (124) from moving axially relative to the side oil reservoir (112); or The protective cap (300) includes: an outer shell (310B), the outer shell (310B) including a bottom wall (311B), a side wall (312B), and an inner cavity (314B) surrounded by the bottom wall (311B) and the side wall (312B), the bottom wall (311B) having an insertion hole; and a movable box (320B), the movable box (320B) being disposed in the inner cavity (314B), the movable box (320B) having a movable partition (321B), the partition (321B) having a through hole aligned with the insertion hole, the partition (321B) dividing the movable box (320B) into an upper part (322B) and a lower part (323B), the upper part (322B)... An elastic element (324B) is provided. The lower part (323B) has a lower wall (323B1) and a peripheral wall (323B2). The peripheral wall (323B2) is a cone that gradually tapers from top to bottom. The lower wall (323B1) has an opening aligned with the insertion hole and the through hole. A plurality of balls (325B) are provided in the lower part (323B). The actuator (124) has a constricted section and a tapered end. The diameter of the constricted section is smaller than the diameter of the two sides of the constricted section. The actuator (124) can be inserted into the insertion hole, the opening and the through hole. The constricted section engages with the balls (325B) to prevent the actuator (124) from disengaging from the protective cap (300).

2. The apparatus of claim 1, wherein, The switching valve (120) also includes: A flexible seal (125) is fitted onto the sealing portion (122b).

3. The apparatus of claim 1, wherein, The sealing member (122) also has a base (122a) located between the elastic member (123) and the sealing portion (122b), the base (122a) being clearance-fitted with the straight section.

4. The apparatus of claim 1, wherein, The stop (220) includes: A pair of positioning rings (221) are fixedly installed on the inner wall of the main body (210) and spaced apart. A retaining ring (222) is held between a pair of positioning rings (221), the retaining ring (222) protruding radially inward and capable of abutting against the actuator (124).

5. The apparatus of claim 1, wherein, The device further includes a central oil reservoir (111) configured to accommodate the protector shaft (S1), the central oil reservoir (111) extending along the central axis (A) and communicating with the side oil reservoir (112), the central oil reservoir (111) having a closure (130) at the first end (113) to close the gap between the central oil reservoir (111) and the protector shaft (S1).

6. The apparatus of claim 5, wherein, A main flow channel (115) is provided between the central oil storage chamber (111) and the side oil storage chamber (112), and the main flow channel (115) is in the shape of an hourglass that narrows in the middle and expands on both sides.

7. The apparatus of claim 6, wherein, A drainage branch (116) is provided between the central oil storage chamber (111) and the side oil storage chamber (112). The drainage branch (116) is connected to the main flow channel (115). One end of the drainage branch (116) is connected to the middle constriction part of the main flow channel (115), and the other end is connected to the side oil storage chamber (112).

8. An electrical submersible pump protector characterized by, The device includes an oil filling device for a submersible pump protector according to any one of claims 1-7, wherein the first connector (100) of the oil filling device is used as the lower connector of the submersible pump protector, the side oil reservoir (112) of the first connector (100) is connected to an oil reservoir located above the oil filling device for the submersible pump protector, and the second connector (200) is connected to the motor shaft (S2).

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