A hydraulic pumping unit's reversing valve leakage monitoring device

Abstract

The application discloses a hydraulic oil pumping unit's reversing valve leakage monitoring device, relates to the technical field of reversing valve leakage monitoring, and comprises a connecting seat and a connecting block, and the outlet of the liquid guide pipe is arranged above the oil collecting shell; one end of the oil collecting shell is fixedly connected with a non-contact capacitive sensor; when the reversing valve is in the middle position working state, if trace leakage occurs at the valve core shoulder near the high-pressure working cavity (such as A or B), the system can quantitatively determine whether the valve core of the reversing valve appears internal leakage failure according to the liquid level data fed back by the non-contact capacitive sensor. The detection structure realizes the physical separation of working oil and leakage oil by relying on mechanical pressure difference distribution, does not need to rely on multi-path pressure and flow sensing signal acquisition, can avoid the detection signal drift interference caused by large amplitude alternating mechanical vibration of the hydraulic oil pumping unit and diurnal environmental temperature difference from the root, and greatly improves the accuracy of trace internal leakage identification of the reversing valve and the long-term operation reliability.

Description

Technical Field

[0001] This invention relates to the field of directional valve leakage monitoring technology, and particularly to a directional valve leakage monitoring device for a hydraulic pumping unit. Background Technology

[0002] Hydraulic pumping units are the core power equipment of rod-operated oil production systems in oilfields. Their reciprocating suction motion is usually controlled by a three-position four-way directional valve. Under harsh working conditions such as long-term high-frequency reciprocating switching, alternating loads, and dusty and drastic temperature differences in the field, the valve core and valve hole sealing pair of the directional valve are prone to wear. This can lead to leakage of oil from the high-pressure working chamber (port A or port B) across the valve core shoulder into the low-pressure working chamber or return oil chamber, i.e., cross-chamber leakage.

[0003] Internal leakage across the cavity not only leads to a sharp drop in system volumetric efficiency and system pressure, but can also cause cylinder locking failure during the pressure holding phase of the pumping unit shutdown, resulting in safety accidents such as the sucker rod automatically sliding down due to gravity. Therefore, real-time online monitoring of internal leakage across the cavity of the reversing valve is of great significance for ensuring safe and efficient production in oil fields.

[0004] Currently, the main methods used in the industry for real-time monitoring of hydraulic valve sealing include the following, but all of them have significant shortcomings when facing the special working conditions of hydraulic pumping units, such as "high-pressure alternating impact, severe mechanical vibration, high impurity content in the medium, and large temperature difference in the field": 1. Ultrasonic or Acoustic Emission Detection Method: This method uses a piezoelectric sensor mounted on the outer surface of the valve body to capture the high-frequency turbulent acoustic emission signal generated by internal leakage throttling. However, hydraulic pumping units, as large steel structures, generate extremely strong multi-frequency, large-amplitude mechanical noise during operation due to their own mechanical transmission, gearbox meshing, sucker rod impact, and hydraulic pump operation. Acoustic emission sensors are highly susceptible to interference from this background mechanical noise, causing characteristic signals to be obscured, leading to frequent false alarms in the diagnostic system. Furthermore, this type of solution involves extremely complex data processing and high hardware costs, making it difficult to widely implement in oilfields.

[0005] 2. Local Temperature Difference Monitoring Method: This method indirectly determines internal leakage by measuring the temperature difference between the valve body on the outer side of the valve core sealing pair and the main oil circuit of the system. However, since the reversing valve body is a heavy metal casting, heat conduction has great thermal inertia, and there is usually a serious lag of tens of minutes from the occurrence of internal leakage to the manifestation of temperature difference, making real-time early warning impossible. More importantly, the diurnal temperature difference in the oilfield environment can reach more than 30°C, and the heat dissipation conditions on the valve body surface are extremely unstable due to the influence of wind speed, rain, snow and other meteorological conditions, resulting in frequent drift of the temperature difference benchmark and extremely poor measurement accuracy. Therefore, a leakage monitoring device for the reversing valve of a hydraulic pumping unit is proposed to address the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a leakage monitoring device for the reversing valve of a hydraulic pumping unit, so as to solve the problems in the background art.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A leakage monitoring device for a reversing valve of a hydraulic pumping unit includes a connecting seat and a connecting block. A reversing valve is fixedly connected to one side of the connecting seat. A connecting block is fixedly connected to the inner side of the connecting seat. A T-tube, a P-tube, an A-tube, and a B-tube are fixedly connected to the inner side of the connecting block. The T-tube, P-tube, A-tube, and B-tube pass through the connecting seat and communicate with the T-port, P-port, A-port, and B-port inside the reversing valve, respectively. A through hole is formed on the inner side of the connecting block, and both the P-tube and the T-tube communicate with this through hole. A liquid guide pipe and an oil collecting shell are fixedly connected to the inner side of the connecting block, and the liquid guide pipe communicates with the through hole inside the connecting block. The outlet of the liquid guide pipe is located above the oil collecting shell. A non-contact capacitive sensor is fixedly connected to one end of the oil collecting shell. A first spring is fixedly connected to the inner side of the through hole inside the connecting block, and a plug is fixedly connected to the other end of the first spring. The plug is slidably connected to the through hole and the T-tube.

[0008] Preferably, the oil collection shell is made of a transparent material.

[0009] Preferably, one end of the T-tube is fixedly connected to a transition cylinder, the inner side of the transition cylinder is fixedly connected to a support rod, one end of the support rod is fixedly connected to a second spring, the other end of the second spring is fixedly connected to a frustum, and the frustum is located inside the transition cylinder.

[0010] Preferably, one end of the transition cylinder is fixedly connected to a guide tube, and a limit rod is slidably connected to the inner side of the guide tube.

[0011] Preferably, a connecting rod is fixedly connected to the bottom end of the connecting block, and a connecting frame is fixedly connected to the other end of the connecting rod. A gear is rotatably connected to the inner side of the connecting frame, and a first rack and a second rack are slidably connected to the inner side of the connecting frame. The first rack and the second rack are evenly meshed. The first rack is fixedly connected to a limiting rod, and an inner rod is fixedly connected to one end of the second rack. An outer cylinder is slidably connected to the outer side of the inner rod, and the outer cylinder is connected to the P-tube.

[0012] Preferably, a baffle is fixedly connected to one end of the gear shaft, and a torsion spring is provided between the baffle and the connecting frame, with the torsion spring sleeved on the outside of the gear shaft.

[0013] Preferably, a siphon tube is fixedly connected to the inner side of the oil collecting shell, the outlet end of the siphon tube is lower than the bottom end of the oil collecting shell, and the top end of the siphon tube is lower than the top surface of the oil collecting shell.

[0014] Compared with the prior art, the present invention has the following beneficial effects: A leakage monitoring device for the directional valve of a hydraulic pumping unit includes a non-contact capacitive sensor, a guide pipe, a plug, a first spring, a transition cylinder, a second spring, a support rod, a cone, and a guide tube. When the directional valve is in the neutral position, if a small leak occurs at the valve core shoulder near the high-pressure working chamber (e.g., port A or port B), hydraulic oil will flow into the oil collection tank along the return oil line (T-pipe). At this time, the pre-set non-contact capacitive sensor can quickly detect the presence of hydraulic oil inside the oil collection tank. The system can quantitatively determine whether the directional valve core has an internal leakage fault based on the liquid level data fed back by the non-contact capacitive sensor. This detection structure relies on mechanical pressure differential diversion to achieve physical separation of the working oil and the leaking oil, eliminating the need for multiple pressure and flow sensors to collect signals. This avoids signal drift interference caused by large-amplitude alternating mechanical vibrations of the hydraulic pumping unit and day-night temperature differences, significantly improving the accuracy of identifying small internal leaks in the directional valve and its long-term operational reliability. Attached Figure Description

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Figure 1 This is a schematic diagram of the overall structure of a reversing valve leakage monitoring device for a hydraulic pumping unit according to the present invention.

[0017] Figure 2 This is a schematic diagram of the installation structure of the connection seat of the leakage monitoring device for the reversing valve of a hydraulic pumping unit according to the present invention.

[0018] Figure 3 This is a schematic diagram of the installation structure of the support rod of a leakage monitoring device for the reversing valve of a hydraulic pumping unit according to the present invention.

[0019] Figure 4 This is a cross-sectional view of the connecting block of a reversing valve leakage monitoring device for a hydraulic pumping unit according to the present invention.

[0020] Figure 5 This is a schematic diagram of the installation structure of the inner rod of a reversing valve leakage monitoring device for a hydraulic pumping unit according to the present invention.

[0021] Figure 6 This is a schematic diagram of the installation structure of the guide tube of a leakage monitoring device for a reversing valve of a hydraulic pumping unit according to the present invention.

[0022] Figure 7This is a schematic diagram of the installation structure of the torsion spring in a leakage monitoring device for a reversing valve of a hydraulic pumping unit according to the present invention.

[0023] Figure 8 This is a schematic diagram of the installation structure of the outer cylinder of a leakage monitoring device for a reversing valve of a hydraulic pumping unit according to the present invention.

[0024] In the diagram: 1. Reversing valve; 2. Connecting seat; 3. Connecting block; 4. Oil collection tank; 5. Non-contact capacitive sensor; 6. Siphon tube; 7. Liquid guide tube; 8. Plug; 9. First spring; 10. Transition cylinder; 11. Second spring; 12. Support rod; 13. Cone; 14. Guide tube; 15. Limiting rod; 16. First rack; 17. Gear; 18. Second rack; 19. Inner rod; 20. Outer cylinder; 21. Connecting frame; 22. Connecting rod; 23. Torsion spring; 24. Baffle; 25. T-tube; 26. P-tube; 27. A-tube; 28. B-tube. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the specific embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size. At the same time, all precision instruments such as lead screws, screws, gears, racks, etc. are equipped with protective structures such as protective covers. As these are common knowledge, they are not described in detail in the specification. It is understandable for those skilled in the art that some common structures and their descriptions may be omitted in the drawings. Based on the specific embodiments of the present invention, all other specific embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] To make the technical means, creative features, objectives, and effects of this invention easier to understand, it should be noted in the description of this invention that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The invention will be further described below in conjunction with specific embodiments.

[0027] Example All kinematic pairs and mechanical component interfaces in this device with relative sliding contact are equipped with independent sealing structures. Corresponding seals are matched to the hydraulic conditions, movement clearances, and media characteristics of each sliding pair to effectively prevent hydraulic oil leakage and dust and impurities from entering, ensuring long-term stable operation of the mechanism.

[0028] like Figures 1-8 As shown, a leakage monitoring device for a directional valve of a hydraulic pumping unit includes a connecting seat 2 and a connecting block 3. A directional valve 1 is fixedly connected to one side of the connecting seat 2. The directional valve 1 is a general-purpose three-position four-way directional valve for hydraulic pumping units. Its basic structure is known in the art. The core components include a valve body, a valve core slidably assembled inside the valve body, and pressure port P, return port T, and working port A for connecting to pressure oil, return oil, and the oil circuits of the two chambers of the oil cylinder, respectively. The assembly relationship and oil circuit connection logic of the components with the working oil port B are all standard industry designs, so they will not be elaborated in detail here. A connecting block 3 is fixedly connected to the inner side of the connecting seat 2. T-pipe 25, P-pipe 26, A-pipe 27, and B-pipe 28 are fixedly connected to the inner side of the connecting block 3. T-pipe 25 is the return oil pipe, and P-pipe 26 is the inlet oil pipe. T-pipe 25, P-pipe 26, A-pipe 27, and B-pipe 28 pass through the connecting seat 2 and connect to the T-port, P-port, A-port, and B-port inside the reversing valve 1. A through hole is opened on the inner side of the connecting block 3, through which P-pipe... Both tube 26 and T-tube 25 are connected to the through hole inside the connecting block 3. A liquid guide tube 7 and an oil collection shell 4 are fixedly connected to the inside of the connecting block 3, and the liquid guide tube 7 is connected to the through hole inside the connecting block 3. The outlet of the liquid guide tube 7 is located above the oil collection shell 4. The oil collection shell 4 is integrally molded from a high-transmittance, insulating, transparent material. The transparent shell has no metal shielding effect, ensuring that the non-contact capacitive sensor 5 mounted on the outside can stably penetrate the shell to collect electric field signals, achieving continuous, non-contact, real-time detection of the accumulated leaked oil level inside the oil collection shell 4. The non-contact capacitive sensor 5 is connected to an external controller via a data cable. The controller can receive and process the signals collected by the sensor in real time, and then intuitively display the measured values ​​on the screen.

[0029] One end of the oil collection tank 4 is fixedly connected to a non-contact capacitive sensor 5, and the inner side of the through hole inside the connecting block 3 is fixedly connected to a first spring 9. The other end of the first spring 9 is fixedly connected to a block 8, and the block 8 is slidably connected to the through hole and the T pipe 25. The conventional reciprocating oil supply and return logic of the reversing valve 1 is existing technology, and is only briefly described here: When the reversing valve 1 is in the working condition, one of the A port and the B port is open. The high-pressure hydraulic oil is introduced into the open A port or B port through the oil supply pipeline P pipe 26 and the valve body P port, driving the actuator to complete the stroke action. The hydraulic oil after the work is done is then returned to the oil tank through the valve body T port and the return oil main T pipe 25. The principle of this oil circuit switching is a well-known technology in the field and will not be described in detail.

[0030] When high-pressure oil is introduced into pipe P26 and the pipeline oil pressure rises, the high-pressure oil simultaneously flows into the through hole inside connecting block 3. The high-pressure oil in the through hole, together with the elastic thrust of the first spring 9, drives the plug block 8 to press the sealing surface tightly, overcoming the reverse pressure of the low-pressure oil inside pipe T25, and completely sealing the inlet of the guide pipe 7 and the diversion opening on the side wall of pipe T25. In this state, the normal working return oil in pipe T25 can be blocked from flowing into guide pipe 7 and oil collection shell 4, avoiding a large amount of working condition return oil entering the metering chamber during operation and causing misjudgment of leakage. At the same time, it does not interfere with the normal flow of the main return oil channel of pipe T25. During this stage, the cone 13 is separated from the pipe of pipe T25 and has no sealing effect.

[0031] When the reversing valve 1 stops and switches to the neutral lock-up position, the valve body ports A and B close simultaneously, the P pipe 26 stops supplying high-pressure oil, the oil pressure in the pipeline drops back to normal pressure, and the plug 8 loses the clamping driving force of the high-pressure oil. At this time, if wear occurs on the mating surface between the valve core and the inner bore of the valve body, the high-pressure oil in chambers A and B will leak slightly through the valve core gap. After the leaked oil flows into the T pipe 25, it will cause the oil pressure in the pipe to rise slightly. The pressurized leaked oil in the T pipe 25 overcomes the pre-tightening force of the first spring 9 and pushes the plug 8 to move away from the side wall of the T pipe 25. The diversion port on the side wall of the T pipe 25 opens, and the small amount of oil generated by the internal leakage of the valve core is guided into the oil collection shell 4 through the liquid guide pipe 7 and accumulated inside.

[0032] A non-contact capacitive sensor 5 is mounted on the outside of the oil collection shell 4. This sensor can penetrate the insulating transparent shell in real time to sense changes in the internal oil medium and quickly collect the oil accumulation signal within the cavity. Based on the liquid level data fed back by the non-contact capacitive sensor 5, the system can quantitatively determine whether the valve core of the reversing valve 1 has an internal leakage fault. This detection structure relies on mechanical pressure differential diversion to achieve physical separation of operating oil and leaking oil. It does not require the acquisition of signals from multiple pressure and flow sensors, and can fundamentally avoid the drift interference of detection signals caused by large-scale alternating mechanical vibration of the hydraulic pumping unit and the temperature difference between day and night. This significantly improves the accuracy of identifying minute internal leaks in the reversing valve and the long-term operational reliability.

[0033] As a further improvement to the present invention, such as Figure 3 and Figure 4As shown, one end of the T-pipe 25 is fixedly connected to a transition cylinder 10, and a support rod 12 is fixedly connected to the inner side of the transition cylinder 10. One end of the support rod 12 is fixedly connected to a second spring 11, and the other end of the second spring 11 is fixedly connected to a cone 13, which is located inside the transition cylinder 10. When there is no high-pressure oil input to the P-pipe 26, the entire pipeline is depressurized. The second spring 11 pushes the cone 13 to press and seal the flow channel of the transition cylinder 10 by its own pre-tightening elastic force, so that the main return oil passage of the lower section of the T-pipe 25 remains closed. This structure can prevent low-pressure oil backflow from the tank side, ensuring that the small amount of leaked oil generated at the valve core shoulder can only flow into the oil collection shell 4 through the guide pipe 7 along the branch path to complete the accumulation and metering; when high-pressure hydraulic oil is introduced into the P pipe 26 and the reversing valve enters the working stroke, the working condition return oil pressure flowing inside the T pipe 25 can overcome the pre-tightening force of the second spring 11, push down the cone 13, and the internal channel of the transition cylinder 10 is fully open, and the main return oil pipeline of the T pipe 25 resumes normal flow, without affecting the normal return oil cooling of the hydraulic pumping unit.

[0034] As a further improvement to the present invention, such as Figure 4 and Figure 7 As shown, a guide tube 14 is fixedly connected to one end of the transition cylinder 10. A limit rod 15 is slidably connected to the inner side of the guide tube 14. When the P pipe 26 stops inputting high-pressure oil and the system is depressurized, the cone 13 presses and seals the transition cylinder 10 under the elastic force of the second spring 11. Simultaneously, the limit rod 15 slides axially along the guide tube 14 to the bottom limit position of the cone 13. Relying on the limit rod 15 to form a mechanical hard limit constraint, the cone 13 in the closed state is positioned and locked for a second time. This can resist the oil pressure impact caused by the slight leakage of oil inside the T pipe 25, prevent the cone 13 from shifting downward and opening the channel under the thrust of the leakage oil pressure, ensure that the transition cylinder 10 always remains in a reliable closed state, prevent the leakage oil from flowing back to the oil tank in advance, and ensure that the slight leakage oil is completely introduced into the oil collection shell 4 to complete the metering.

[0035] As a further improvement to the present invention, such as Figure 4 and Figure 7As shown, a connecting rod 22 is fixedly connected to the bottom end of the connecting block 3, and a connecting frame 21 is fixedly connected to the other end of the connecting rod 22. A gear 17 is rotatably connected to the inner side of the connecting frame 21, and a first rack 16 and a second rack 18 are slidably connected to the inner side of the connecting frame 21. Both the first rack 16 and the second rack 18 mesh with the gear 17. The first rack 16 is fixedly connected to the limiting rod 15. An inner rod 19 is fixedly connected to one end of the second rack 18, and an outer cylinder 20 is slidably connected to the outer side of the inner rod 19. The outer cylinder 20 is connected to the P pipe 26. When high-pressure hydraulic oil is introduced into the P pipe 26, the high-pressure oil is synchronously introduced into the oil cavity inside the outer cylinder 20. The high-pressure oil pressure acts on the end face of the inner rod 19, driving the inner rod 19 to drive the second rack 18 to produce axial displacement. The second rack 18 meshes with the gear 17 for transmission, and the gear 17 drives the first rack 16 to move synchronously away from the transition cylinder 10. The first rack 16, in conjunction with the limiting rod 15, disengages from the limiting support position at the bottom of the cone 13, releasing the mechanical locking constraint on the cone 13. In this way, the subsequent oil return in the T-tube 25 can smoothly overcome the elastic force of the second spring 11 to push the cone 13 downward, ensuring the normal conduction of the main oil return channel of the T-tube 25.

[0036] As a further improvement to the present invention, such as Figure 7 As shown, a baffle 24 is fixedly connected to one end of the shaft of gear 17. A torsion spring 23 is provided between the baffle 24 and the connecting frame 21, and the torsion spring 23 is sleeved on the outside of the shaft of gear 17. The torsion spring 23 continuously applies a pre-tightening torque to gear 17 towards the transition cylinder 10 through the baffle 24. When the P pipe 26 stops supplying high-pressure hydraulic oil and the oil pressure inside the outer cylinder 20 drops back to normal pressure, the inner rod 19 and the second rack 18 are no longer constrained by the oil pressure drive. Under the action of the constant rotational torque of the torsion spring 23, gear 17 meshes with the first rack 16 in the opposite direction, and the traction limit rod 15 slides and resets along the guide tube 14 to the bottom limit position of the cone 13, re-establishing the mechanical support and locking of the cone 13.

[0037] The reason this case uses a hydraulic and mechanical linkage structure to control the on / off state of T-pipe 25, instead of a traditional solenoid valve for pipeline switching, is that its core advantages lie in three aspects: adaptability to operating conditions, safety and explosion-proof features, and detection accuracy. First, hydraulic pumping units continuously generate large-scale alternating vibrations during operation. Conventional solenoid valves rely on electromagnetic armatures and contacts to complete their actions. Under long-term high-frequency vibration, they are prone to failure problems such as armature jamming and poor contact, resulting in poor overall operational reliability. This solution uses the hydraulic oil pressure of the pipeline itself as the driving force, and is equipped with a pure mechanical transmission pair consisting of a first spring 9, a second spring 11, a rack 16, and a cone 13. There are no electrically moving parts, which enhances the vibration resistance and meets the long-term continuous and stable operation requirements of unattended pumping equipment in the field. Furthermore, there is no need to lay out additional power supply lines for solenoid valves or install electrical control units, making the overall structure more streamlined and reducing on-site installation and modification costs.

[0038] Secondly, oilfield operation sites are open-air environments, generally characterized by dampness, dust, and flammable and explosive conditions of oil and gas. Over time, the coils and wiring of electrically controlled solenoid valves are prone to electrical faults such as coil burnout, wiring aging, contact oxidation and adhesion, and signal distortion. This solution features an all-mechanical structure with no electrical components, thus avoiding the aforementioned safety hazards at the source. It is compatible with the first-level explosion-proof operation requirements of oilfields, significantly reducing the probability of equipment failure. Its environmental adaptability and operational safety are significantly superior to the solenoid valve control scheme.

[0039] Third, traditional solenoid valves are prone to defects such as electrical control drift, electromagnetic interference, and micro-leakage at the valve port, which can cause misjudgments in pipeline on / off logic and directly reduce the accuracy of internal leakage monitoring of directional valve 1. In contrast, this mechanical linkage structure relies on the physical coupling effect of hydraulic pressure difference and the elasticity of the first spring 9 and the second spring 11 to achieve precise on / off switching. It is not affected by voltage fluctuations, electromagnetic interference, or ambient temperature drift. It can clearly distinguish between the large flow return oil of directional valve 1 during normal operation and the small amount of leakage oil in the middle position. From the hardware structure level, it avoids measurement misjudgment and effectively ensures the accuracy and stability of micro-leakage detection.

[0040] Traditional directional valve leakage monitoring devices operate with independent functional components, lacking mechanical linkage constraints. They either rely on electrically controlled solenoid valves to switch oil circuits or indirectly determine leakage using only a single sensing element, resulting in numerous operational drawbacks. This invention integrates a hydraulic drive transmission assembly, a cone-shaped limit sealing assembly, a leakage diversion assembly, a siphon oil collection assembly, and a non-contact capacitive sensing assembly into a single unit. It achieves full mechanical synchronous interlocking based on oil pressure changes in the P-tube 26: During operation, it automatically seals the leakage branch and opens the main return oil channel; after depressurization in the neutral position, it automatically locks the main return oil and opens the leakage collection branch, eliminating the need for electronic control components to participate in logic switching. The various mechanical structures are mutually constrained and work collaboratively, not simply a combination of standard parts. The integrated linkage structure achieves physical separation of normal return oil and trace leakage oil, combined with non-contact capacitive sensing for accurate quantitative detection. This effectively avoids problems such as vibration interference, electrical faults, and measurement misjudgments in existing technologies, demonstrating significant innovative advantages compared to existing solutions.

[0041] As a further improvement to the present invention, such as Figure 4 and Figure 6 As shown, a siphon pipe 6 is fixedly connected to the inner side of the oil collecting tank 4. The outlet end of the siphon pipe 6 is lower than the bottom end of the oil collecting tank 4, the top end of the siphon pipe 6 is lower than the top surface of the oil collecting tank 4, and the highest point of the arch of the siphon pipe 6 is lower than the upper opening end face of the oil collecting tank 4. A collection bucket is provided below the liquid outlet end of the siphon pipe 6 to collect the hydraulic oil discharged by the siphon. When the oil level of the leakage accumulated inside the reversing valve 1 rises and overflows the highest point of the arch of the siphon pipe 6, the inside of the pipeline is completely filled with oil, automatically forming a siphon negative pressure effect. Under the continuous suction action of the siphon pressure difference, all the leaked oil accumulated inside the oil collecting tank 4 will be quickly discharged through the siphon pipe 6 and finally flow into the collection bucket below for unified collection.

[0042] The above are preferred embodiments of the present invention. The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the scope of protection of the present invention. All such changes and modifications fall within the scope of protection of the present invention as defined by the appended claims and their equivalents.

Claims

1. A reversing valve leakage monitoring device for hydraulic pumping unit, comprising a connecting seat (2) and a connecting block (3), characterized in that: A reversing valve (1) is fixedly connected to one side of the connecting seat (2), and a connecting block (3) is fixedly connected to the inner side of the connecting seat (2). A T-tube (25), a P-tube (26), an A-tube (27), and a B-tube (28) are fixedly connected to the inner side of the connecting block (3). The T-tube (25), P-tube (26), A-tube (27), and B-tube (28) pass through the connecting seat (2) and communicate with the T-port, P-port, A-port, and B-port inside the reversing valve (1). A through hole is opened on the inner side of the connecting block (3). The T-tube (25) and P-tube (26) are both connected to the connecting block. (3) The through hole on the inner side is connected. The inner side of the connecting block (3) is fixedly connected to the liquid guide pipe (7) and the oil collection shell (4), and the liquid guide pipe (7) is connected to the through hole on the inner side of the connecting block (3). The outlet of the liquid guide pipe (7) is located above the oil collection shell (4). One end of the oil collection shell (4) is fixedly connected to a non-contact capacitive sensor (5). The inner side of the through hole on the inner side of the connecting block (3) is fixedly connected to a first spring (9). The other end of the first spring (9) is fixedly connected to a block (8), and the block (8) is slidably connected to the through hole and the T-tube (25).

2. The leakage monitoring device for the reversing valve of a hydraulic pumping unit according to claim 1, characterized in that: The oil collection shell (4) is made of transparent material.

3. The reversing valve leakage monitoring device for a hydraulic pumping unit according to claim 1, characterized in that: One end of the T-tube (25) is fixedly connected to a transition cylinder (10), and a support rod (12) is fixedly connected to the inner side of the transition cylinder (10). One end of the support rod (12) is fixedly connected to a second spring (11), and the other end of the second spring (11) is fixedly connected to a frustum (13), and the frustum (13) is located inside the transition cylinder (10).

4. The leakage monitoring device for the reversing valve of a hydraulic pumping unit according to claim 3, characterized in that: One end of the transition cylinder (10) is fixedly connected to a guide tube (14), and a limit rod (15) is slidably connected to the inner side of the guide tube (14).

5. The reversing valve leakage monitoring device for a hydraulic pumping unit according to claim 1, characterized in that: The bottom end of the connecting block (3) is fixedly connected to a connecting rod (22), and the other end of the connecting rod (22) is fixedly connected to a connecting frame (21). The inner side of the connecting frame (21) is rotatably connected to a gear (17). The inner side of the connecting frame (21) is slidably connected to a first rack (16) and a second rack (18), and both the first rack (16) and the second rack (18) mesh with the gear (17). The first rack (16) is fixedly connected to a limiting rod (15). One end of the second rack (18) is fixedly connected to an inner rod (19), and the outer side of the inner rod (19) is slidably connected to an outer cylinder (20), and the outer cylinder (20) is connected to the P pipe (26).

6. The leakage monitoring device for the reversing valve of a hydraulic pumping unit according to claim 5, characterized in that: A baffle (24) is fixedly connected to one end of the shaft of the gear (17). A torsion spring (23) is provided between the baffle (24) and the connecting frame (21), and the torsion spring (23) is sleeved on the outside of the shaft of the gear (17).

7. The reversing valve leakage monitoring device for a hydraulic pumping unit according to claim 1, characterized in that: A siphon tube (6) is fixedly connected to the inner side of the oil collecting shell (4). The outlet end of the siphon tube (6) is lower than the bottom end of the oil collecting shell (4), and the top end of the siphon tube (6) is lower than the top surface of the oil collecting shell (4).

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