Totally-closed leakproof electric valve and early warning and leakage discharging method

Abstract

The invention discloses a totally-closed leakproof electric valve and an early warning and leakage discharging method. An actuator assembly and a valve assembly of the electric valve form a closed cavity through a closed connecting flange and a sealing device at a joint surface; and the actuator assembly is provided with a pressure detection device and a leakage discharge device. A multi-sealing structure is arranged on the manual shaft, and connection and sealing of an inner circuit and an outer circuit are achieved through a pressure-bearing wiring board. According to the early warning and leakage discharging method, early warning maintenance is triggered by monitoring the leakage condition of the fluid medium according to the structure, the leakage discharging device is started during maintenance, and active discovery and safety maintenance disposal of leakage are achieved. The leakage fluid medium is limited in the closed cavity, so that the possibility of outward leakage is greatly reduced; real-time early warning of leakage is achieved through detection of the leakage condition, leakage media are safely guided out through the leakage discharging device, and the operation safety and maintainability of the valve under the working conditions of burning explosion, dangerous chemical or corrosive media are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric valve, in particular to a fully-closed anti-leakage electric valve, and a pre-warning and leakage-removing method of electric valve. BACKGROUND

[0002] As a key execution component in fluid automatic control system, electric valve is usually composed of three parts: valve, coupling and actuator. Among them, the valve undertakes the core function of fluid on-off or regulation, and the valve stem inside the valve body is mechanically connected with the output shaft of the actuator through the coupling; the actuator drives the output shaft to rotate or move linearly according to the electric control signal, and then drives the valve stem to act, so as to realize the opening or closing of the valve. Electric valve is widely used in industrial automation system, and is suitable for water, steam, heat carrier, chemical fluid and even process medium with certain corrosiveness or danger.

[0003] However, in the prior art, the sealing between the valve stem and the valve body depends on the mechanical sealing structure, and the connection parts between the coupling and the valve and between the coupling and the actuator are usually not sealed. Since the valve stem needs to move back and forth frequently during operation, the mechanical seal will inevitably wear out, and the loosening of the connection parts will also aggravate the sealing failure. Once the sealing performance is reduced, the controlled fluid may leak from the valve stem and escape to the external environment through the non-sealed coupling area. For flammable, explosive or toxic medium, such leakage not only threatens the safe operation of the equipment, but also may cause serious safety accidents. Even for ordinary medium, leakage will cause waste of resources, environmental pollution and system efficiency reduction.

[0004] In addition, there is a lack of effective means to monitor whether leakage has occurred at the valve stem in the prior art, so that even if the internal sealing has deteriorated or there is a small leakage, the operator is difficult to detect in time. Leakage is often discovered after it has accumulated to a certain extent and even has affected the external environment, missing the best opportunity for early intervention and maintenance. This passive response mode not only increases the operation and maintenance cost, but also hides safety hazards in high-risk working conditions. SUMMARY

[0005] The present application provides a fully-closed anti-leakage electric valve and a pre-warning and leakage-removing method, which aims to realize complete isolation between the valve stem sealing area and the external environment, greatly eliminating fluid leakage caused by mechanical seal wear; provide monitoring means for potential leakage at the valve stem, ensure that leakage can be accurately identified and pre-warning can be given at the early stage of leakage, avoid safety risks, environmental pollution or system failure caused by leakage expansion.

[0006] The technical scheme of the present application is as follows: The application discloses a full-closed and leakage-proof electric valve, which comprises an actuator assembly and a valve assembly, the valve assembly comprises a valve body and a valve rod installed in the valve body, a first sealing device is arranged between the valve rod and the valve body, an output shaft of the actuator assembly is mechanically connected with an end of the valve rod of the valve assembly, the actuator assembly is provided with a first closed connection flange, the valve assembly is provided with a second closed connection flange, the first closed connection flange is connected with the second closed connection flange, and a second sealing device is arranged at a joint surface, so that a cavity part outside the first sealing device in the valve assembly and an inner cavity part of the actuator assembly are communicated to form a closed cavity; a detection device for detecting leakage of a medium in the inner cavity of the actuator assembly is further installed on the actuator assembly; and a leakage discharge device communicated with the inner cavity of the actuator assembly is further installed on the actuator assembly.

[0007] Further, the actuator assembly comprises a base, a manual shaft is rotatably installed on the base, and the manual shaft is in transmission connection with the output shaft of the actuator assembly; and a manual sealing mechanism is arranged at the manual shaft.

[0008] Further, the manual sealing mechanism comprises a third sealing device arranged between the manual shaft and the base, and / or a sealing blind cap installed on the base and covering an outer end of the manual shaft.

[0009] Further, the base is provided with a first circular boss, an aperture is formed in the first circular boss, and the manual shaft passes through the aperture; the third sealing device comprises a first sealing ring installed on the manual shaft and in contact with an inner wall of the aperture; the third sealing device further comprises a second sealing gasket arranged between an annular protrusion at an inner end of the manual shaft and an inner wall of the base; the sealing blind cap is in threaded connection with the first circular boss, and a third sealing gasket is further arranged between an inner wall of the sealing blind cap and an end surface of the first circular boss.

[0010] Further, a pressure-bearing terminal block is further installed outside the actuator assembly, and the pressure-bearing terminal block is used for realizing electrical connection between internal electrical components of the actuator assembly and external electrical components; the pressure-bearing terminal block is in sealed connection with the actuator assembly.

[0011] Further, the detection device is a medium pressure detection device, a medium component detection device or a medium conductivity detection device.

[0012] Further, the leakage device comprises a connecting seat, a leakage valve core, a sealing head, a sealing cap, a spring, a second sealing ring and a fourth sealing gasket; the connecting seat is installed on the base, and the connecting seat is provided with a first center hole, a second center hole and a third center hole connected in sequence from inside to outside; the inner diameter of the second center hole is smaller than that of the first center hole and the third center hole; the leakage valve core comprises a rod part and a head part connected with the inner end of the rod part; the diameter of the head part is larger than the inner diameter of the second center hole and smaller than the inner diameter of the first center hole; the outer end of the rod part is provided with a center blind hole, and the area close to the head part of the rod part is provided with a side hole communicated with the center blind hole; the rod part is in sliding fit with the second center hole, the head part is located in the first center hole, the second sealing ring is sleeved outside the rod part and located between the head part and the side hole; the sealing head is located in the third center hole and connected with the outer end of the rod part, and the sealing head is provided with a center through hole communicated with the center blind hole; the spring is arranged in the third center hole and used for pushing the sealing head and the leakage valve core outwardly; the fourth sealing gasket is installed between the sealing head and the outer end face of the connecting seat. The sealing cap is connected with the connecting seat through thread cooperation, used for pressing the sealing head and the fourth sealing gasket inwardly, and in the pressing state, the outer edge of the fourth sealing gasket is in contact with the inner wall of the sealing cap.

[0013] Further, the leakage device further comprises a sealing connecting head, the inner end of the sealing connecting head is used for being connected with the connecting seat through thread cooperation, and the outer end is used for connecting a leakage pipeline.

[0014] Further, the fourth sealing device is installed between the output shaft and the shaft hole located at the bottom of the base and through which the output shaft passes, so as to block the fluid leaked from the first sealing device from entering the inside of the actuator assembly.

[0015] The early warning and leakage method of the fully-closed anti-leakage electric valve, the leakage state detected by the real-time monitoring and detecting device is monitored, if the state reaches a preset threshold, a warning signal is sent out to prompt maintenance, the leakage device is opened before maintenance, and the fluid entering the inner cavity of the actuator assembly is discharged, and the leakage method is as follows: first, the sealing cap is removed, at this time, the leakage valve core is pushed outwardly under the action of the spring until the head part extrudes the second sealing ring, so that the second sealing ring is located against the outer end face of the first center hole, at this time, the fluid in the inside is temporarily blocked outside the side hole, and temporary sealing is realized; then, the sealing connecting head is installed and connected with the leakage pipeline, after the sealing connecting head is tightened, the sealing head and the fourth sealing gasket are pressed again, so that the fluid passage is opened, the leaked fluid can enter the center blind hole from the side hole, and is guided to a designated collecting device through the sealing connecting head and the leakage pipeline.

[0016] Compared with the prior art, the present application has the following positive effects: 1. The application adopts a first closed connection flange and a second closed connection flange to realize the connection of the valve assembly and the actuator assembly, and sets a second sealing device on the joint surface, so that the fluid that may leak from the valve stem is limited in the closed cavity formed by the outer end of the valve body (the area outside the mechanical seal) and the actuator, thereby effectively blocking the path of the leaked fluid escaping to the external environment, and fundamentally solving the persistent leakage problem of the existing electric valve caused by the wear of the valve stem seal.

[0017] 2. On the basis of the above-mentioned fully-closed structure, the application further configures a detection device, for example, by using the principle that the leakage of fluid from the valve stem will cause the pressure in the closed cavity to rise, the real-time perception and early warning of early micro-leakage are realized, the lagging defect of the traditional electric valve that can only rely on manual inspection or post-facto phenomenon to judge leakage is overcome, and the safety and maintainability of the system operation are significantly improved.

[0018] 3. For the potential secondary leakage point of the actuator assembly, the manual shaft part, the application sets a multiple sealing structure including a first sealing ring, a second sealing gasket and a sealing blind cap, so that even in the case of failure of the main seal, the fluid can still be effectively prevented from leaking from the gap at the manual shaft, further ensuring the reliability of the overall seal.

[0019] 4. In order to avoid damage to electrical components caused by process medium entering the inner cavity of the actuator, the application uses a pressure-bearing terminal block to move sensitive components such as control circuit boards that are not resistant to corrosion to the outside of the actuator, and ensures the sealing of the electrical connection channel through the integrated sealing structure of the flange plate, insulator and terminal post, which not only maintains the integrity of the electrical function, but also enhances the long-term stability of the equipment in corrosive or dangerous medium working conditions.

[0020] 5. The application integrates a leak removal device with self-sealing function on the actuator assembly, which can safely guide the leaked medium accumulated in the inner cavity to the designated collection device by detaching the sealing cap, installing the sealing connector and connecting the leak removal pipeline after the early warning of the leak detection device is triggered. The leak removal device can still rely on the spring force and the sealing structure to automatically close the flow passage after the sealing cap is detached and before the external pipeline is connected, ensuring that no secondary leakage occurs during the operation process, and is especially suitable for emergency disposal scenarios of flammable, explosive or toxic media.

[0021] 6. The application further sets a fourth sealing device at the output shaft of the actuator assembly to block the fluid leaked from the first sealing device from entering the inside of the actuator assembly, further improving the sealing effect. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the fully-closed leak-proof electric valve in Example One, and the pressure sensor and the manual sealing mechanism part are cut away in the figure.

[0023] Figure 2 Figure 1 is a perspective view of the full-enclosed leak-proof electric valve. Figure 1 Figure 2 is a partial enlarged view of part A in Figure 1.

[0024] Figure 3 Figure 3 is a side view of the full-enclosed leak-proof electric valve, with the pressure-bearing terminal board and leak-eliminating device being partially cut away.

[0025] Figure 4 Figure 4 is a perspective view of the full-enclosed leak-proof electric valve. Figure 3 Figure 5 is a partial enlarged view of part B in Figure 4.

[0026] Figure 5 Figure 6 is a perspective view of the full-enclosed leak-proof electric valve. Figure 3 Figure 7 is a partial enlarged view of part C in Figure 6.

[0027] Figure 6 Figure 8 is a structural schematic diagram of the structure for discharging internal fluid by installing a sealed connector and a leak-eliminating pipeline.

[0028] Figure 7 Figure 9 is a schematic diagram of the connection relationship between the output shaft of the actuator assembly and the valve stem of the valve assembly in Example 2.

[0029] The reference signs include: 1, housing, 2, base, 3, pressure detection device, 4, pressure-bearing terminal board, 5, manual sealing mechanism, 6, first closed flange, 7, second closed flange, 8, leak-eliminating device, 9, valve body, 10, manual shaft, 11, third sealing ring, 12, valve stem, 13, output shaft, 401, flange plate, 402, first sealing gasket, 403, insulator, 404, terminal post, 501, sealing blind cap, 502, first sealing ring, 503, second sealing gasket, 504, third sealing gasket, 801, connecting seat, 802, leak-eliminating valve core, 803, second sealing ring, 804, side hole, 805, center blind hole, 806, spring, 807, fourth sealing gasket, 808, sealing head, 809, sealing cap, 810, sealed connector, 811, leak-eliminating pipeline. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Example 1

[0031] A full-enclosed leak-proof electric valve, as shown in Figure 1 and Figure 3 , comprises an actuator assembly and a valve assembly.

[0032] The actuator assembly specifically comprises a base 2 and a cover 1 mounted on the base 2, and a sealing ring or gasket is arranged at the joint between the cover 1 and the base 2. A motor is mounted in the inner cavity formed by the base 2 and the cover 1, and the motor is mechanically connected with an output shaft 13 of the actuator assembly to drive the valve rod 12 to rotate and realize the opening control of the valve. Figure 2 A manual shaft 10 is mounted on the base 2 in a rotary connection mode, and an outer hexagonal hole or an inner hexagonal hole is arranged at the outer end of the manual shaft 10. The manual shaft 10 is in transmission connection with the output shaft 13 of the actuator assembly. In this embodiment, the manual shaft 10 is in transmission connection with the output shaft 13 through a gear transmission mechanism. After the motor is stopped, the output shaft 13 of the actuator assembly can be rotated by rotating the manual shaft 10, so as to realize the manual control of the valve. The internal electrical part of the actuator is provided with a circuit and components with a corresponding protection level according to the properties of the medium.

[0033] The valve assembly comprises a valve body 9 and a valve rod 12 mounted in the valve body 9, and a first sealing device (such as a mechanical sealing mechanism such as a sealing ring or a gasket) is arranged between the valve rod 12 and the valve body 9. The end of the valve rod of the valve assembly is mechanically connected with the output shaft of the actuator assembly, and in this embodiment, the two are mechanically connected through a shaft coupling.

[0034] As shown in Figure 1 and Figure 3 , the bottom of the actuator assembly (the base 2) is provided with a first closed connection flange 6, and the top of the valve assembly (the valve body 9) is provided with a second closed connection flange 7. The first closed connection flange 6 is connected with the second closed connection flange 7 and a second sealing device is arranged at the joint surface, so that the cavity part outside the first sealing device in the valve assembly is in communication with the inner cavity part of the actuator assembly to become a closed cavity, and the fluid leaked from the first sealing device will enter the closed cavity. In this embodiment, the second sealing device is a sealing ring or a gasket mounted between the first closed connection flange 6 and the second closed connection flange 7. When a sealing ring is used, a sealing groove should be processed on one side of the flange end face, and the sealing ring is placed in the sealing groove, and the sealing ring is pressed to realize sealing. When a gasket is used, the gasket is annular, corresponding to the annular area of the bolts connecting the two flanges. The bolts are in turn pressed against the two flanges and the gasket between the two flanges, and finally the gasket is pressed to realize sealing.

[0035] The fluid entering the above-mentioned closed cavity may erode the motor and other components on the one hand, and may further leak from the manual shaft 10 to the external environment on the other hand. Therefore, the following improvements are made to the electric valve around the closed cavity: First, the motor and proximity switch are selected to be corrosion resistant, fluorine resistant, oil resistant and waterproof, so as to avoid the influence of the entering fluid on the normal work of the electrical components.

[0036] Second, the electrical components without corrosion resistance, fluorine resistance, oil resistance and waterproof performance, such as the control circuit board, are transferred to the outside of the actuator assembly, and a pressure-bearing terminal block 4 is installed outside the actuator assembly. The pressure-bearing terminal block 4 is used to realize the circuit connection between the electrical components inside the actuator assembly and the electrical components outside the actuator assembly, and the pressure-bearing terminal block 4 is in sealed connection with the actuator assembly. Specifically, as shown in Figure 4 the pressure-bearing terminal block 4 includes a flange plate 401, an insulator 403 and a plurality of terminal posts 404 penetrating through the insulator 403. The insulator 403 is embedded in the square through hole in the middle of the flange plate 401 and sintered integrally with the flange plate 401 and the terminal posts 404, so as to realize the sealed connection between the terminal posts 404 and the insulator 403 and between the flange plate 401 and the insulator 403. As an optional embodiment, the insulator 403 can also be an insulating castable material, which is casted integrally with the flange plate 401 and the terminal posts 404 to realize the sealed connection. The inner end of the terminal post 404 is used for electrical connection with the electrical components inside the actuator assembly, and the outer end is used for electrical connection with the electrical components outside the control circuit board. The flange plate 401 is installed on the base 2 by screws, and a first sealing gasket 402 is arranged between the flange plate 401 and the base 2 to realize the sealing between the pressure-bearing terminal block 4 and the actuator assembly.

[0037] Third, the easily-leaking point at the manual shaft 10 is sealed. Specifically, the manual sealing mechanism 5 is arranged at the manual shaft 10. The manual sealing mechanism 5 includes a third sealing device arranged between the manual shaft 10 and the base 2, and / or a sealing blind cap 501 installed on the base 2 and covering the outer end of the manual shaft 10. Further, as shown in Figure 2 the base 2 is provided with a first circular boss, and a light hole is formed in the first circular boss, and the manual shaft 10 penetrates through the light hole. The third sealing device includes a first sealing ring 502 installed on the manual shaft 10, which is in contact with the inner wall of the light hole. The third sealing device further includes a second sealing gasket 503 arranged between the annular protrusion at the inner end of the manual shaft 10 and the inner wall of the base 2. The sealing blind cap 501 is threadedly connected with the first circular boss, and a third sealing gasket 504 is further arranged between the inner wall of the sealing blind cap 501 and the end surface of the first circular boss. As an optional embodiment, only the third sealing device or only the sealing blind cap 501 can be arranged at the manual shaft 10.

[0038] Through the above sealing measures, it can be ensured that if leakage occurs at the first sealing device, the fluid entering the actuator assembly will not continue to leak outward, but this also causes the external inspection personnel to be unable to timely discover the leakage at the valve stem. The fluid accumulates inside the actuator assembly for a long time, and there is still a safety hazard.

[0039] To this end, a detection device for detecting the leakage state of the medium in the actuator assembly is further installed on the actuator assembly. The detection device can be a medium pressure detection device. It can also be a medium component detection device. If it is detected that the content of a certain medium component in the actuator assembly is greater than a preset threshold, the system sends a warning signal to remind the operator that leakage has occurred at the valve stem. The detection device can also be a medium conductivity detection device. If it is detected that the conductivity of the medium in the actuator assembly is greater than a preset threshold, the system sends a warning signal to remind the operator that leakage has occurred at the valve stem. The following describes the option of taking the detection device as a medium pressure detection device.

[0040] As shown in Figure 1 A pressure detection device 3 for detecting the pressure in the cavity of the actuator assembly is further installed on the actuator assembly. The entry of fluid will cause the pressure in the cavity of the actuator assembly to rise, so the pressure value detected by the pressure detection device 3 can be used to judge whether leakage has occurred inside. In this embodiment, the pressure detection device 3 is a pressure sensor, which is a cylindrical body with external threads. The pressure sensor cooperates with a threaded hole on the base 2 of the actuator assembly, which is in communication with the inner cavity of the actuator assembly, so that the pressure sensor can accurately detect the pressure in the inner cavity. A raw rubber tape or sealant can be added between the pressure sensor and the threaded hole to prevent leakage. A fastening nut can also be installed on the pressure sensor, and sealant or a sealing gasket is applied between the fastening nut and the base 2 to prevent leakage.

[0041] The actuator assembly is also provided with a leakage discharge device 8 in communication with the inner cavity thereof. When the fluid controlled by the electric valve is a liquid or a gas with a density greater than air, the leakage discharge device 8 is arranged at the bottom of the actuator assembly. When the fluid controlled by the electric valve is a gas with a density less than air, the leakage discharge device 8 is arranged at the top of the actuator assembly.

[0042] In this embodiment, the leakage discharge device 8 is arranged at the bottom of the base 2. Specifically, as shown in Figure 5As shown, the leakage device 8 comprises a connecting seat 801, a leakage valve core 802, a sealing head 808, a sealing cap 809, a spring 806, a second sealing ring 803 and a fourth sealing gasket 807. The base 2 is provided with a second circular boss, and the connecting seat 801 is installed on the second circular boss in a threaded cooperation manner. The connecting seat 801 is provided with a first central hole, a second central hole and a third central hole connected in sequence from inside to outside. The inner diameter of the second central hole is smaller than that of the first central hole and the third central hole. The leakage valve core 802 comprises a stem part and a head part connected with the inner end of the stem part. The diameter of the head part is larger than the inner diameter of the second central hole and smaller than the inner diameter of the first central hole. The outer end of the stem part is provided with a central blind hole 805, and the stem part is provided with a side hole 804 communicating with the central blind hole 805 near the head part. The stem part is in sliding cooperation with the second central hole, and the head part is located in the first central hole. The second sealing ring 803 is sleeved on the outer side of the stem part and located between the head part and the side hole 804. The sealing head 808 is located in the third central hole and connected with the outer end of the stem part, and the sealing head 808 is provided with a central through hole communicating with the central blind hole 805. The spring 806 is arranged in the third central hole and used to push the sealing head 808 and the leakage valve core 802 outward. The fourth sealing gasket 807 is arranged between the sealing head 808 and the outer end face of the connecting seat 801. The sealing cap 809 is connected with the connecting seat 801 in a threaded cooperation manner and used to press the sealing head 808 and the fourth sealing gasket 807 inward. In the pressed state, the outer edge of the fourth sealing gasket 807 is in contact with the inner wall of the sealing cap 809.

[0043] Further, as shown in Figure 6 the leakage device 8 further comprises a sealing connecting head 810. The inner end of the sealing connecting head 810 is used to be connected with the connecting seat 801 in a threaded cooperation manner, and the outer end is used to connect a leakage pipeline 811.

[0044] The working principle of the electric valve is as follows: when the first sealing device between the valve stem of the valve assembly and the valve body 9 fails due to wear and tear, the controlled fluid may leak. Since the valve assembly and the actuator assembly are connected into a closed whole through the first closed connection flange 6, the second closed connection flange 7 and the second sealing device, the leaked fluid is limited in the closed cavity formed by the outer end area of the valve body 9 and the inner cavity of the actuator assembly, and cannot directly leak to the external environment. With the gradual entry of the leaked fluid, the pressure in the closed cavity will rise. The pressure detection device 3 installed on the cavity can monitor this pressure change in real time. When the monitored pressure value is greater than the preset threshold value, the system can send a warning signal to remind the operator that leakage has occurred at the valve stem. After receiving the warning, the operator can operate the leakage discharge device 8 as needed to safely discharge the accumulated fluid. Specifically, first, the sealing cap 809 is removed, at which time the leakage valve core 802 is ejected outward under the action of the spring 806 until the head part extrudes the second sealing ring 803, so that the latter is pressed against the outer end surface of the first central hole, at which time the internal fluid is temporarily blocked outside the side hole 804 and the central blind hole 805, realizing temporary sealing. Then, as shown in the figure, the sealing connector 810 is installed and connected to the leakage discharge pipeline 811, and after the sealing connector 810 is quickly tightened, the sealing head 808 and the fourth sealing gasket 807 are again pressed tightly, so that the fluid passage is opened, the leaked fluid can enter the central blind hole 805 from the side hole 804, and is guided to the designated collection device through the sealing connector 810 and the leakage discharge pipeline 811. In the entire process, by sealing the manual shaft 10, selecting corrosion-resistant components, and setting the pressure-bearing terminal block 4, it is ensured that even if the main sealing fails, the fluid will not leak from the manual shaft 10 or the electrical interface, and the internal sensitive components are effectively protected, realizing all-round sealing protection and safe operation. Figure 6

[0045] Based on the above structure, the application also provides a warning and leakage discharge method. The method comprises: monitoring the pressure detected by the pressure detection device 3 in real time, and if the pressure is greater than the preset threshold value, a warning signal is sent to prompt maintenance, and before maintenance, the leakage discharge device 8 is opened to discharge the fluid entering the inner cavity of the actuator assembly. Through this method, real-time perception and active treatment of early micro-leakage can be realized, and the safety and maintainability of system operation are significantly improved. Embodiment two

[0046] The difference between this embodiment and embodiment one is that a fourth sealing device is further installed between the output shaft 13 of the actuator assembly and the shaft hole through which the output shaft 13 passes at the bottom of the base 2. Figure 7 The fourth sealing device is a third sealing ring 11 sleeved on the output shaft 13.

[0047] ​With the sealing device, even if the first sealing device at the valve stem 12 fails, the leaked fluid will be blocked by the fourth sealing device when passing through the gap between the output shaft 13 and the shaft hole, so as to keep the fluid in the valve assembly as much as possible and avoid entering the actuator assembly.

[0048] Figure 7 In the embodiment, the upper end of the valve stem 12 is hexagonal, directly matched with the hexagonal hole at the bottom of the output shaft 13 to realize the transmission connection. The structure is more compact relative to the coupling. Those skilled in the art should understand that even if the fourth sealing device is added, the output shaft 13 and the valve stem 12 can also realize the transmission connection through other mechanisms including the coupling. The fourth sealing device is only related to the structure of the output shaft 13 and the base 2, and is irrelevant to the transmission mode between the output shaft 13 and the valve stem 12.

[0049] It should be noted that, for those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. The scope of the present application is defined by the claims rather than the above description.

Claims

1. A fully enclosed, leak-proof electric valve, comprising an actuator assembly and a valve assembly, the valve assembly comprising a valve body (9) and a valve stem (12) installed in the valve body (9), a first sealing device being provided between the valve stem (12) and the valve body (9), and the output shaft (13) of the actuator assembly being mechanically connected to the end of the valve stem (12) of the valve assembly, characterized in that: The actuator assembly is provided with a first closed connection flange (6), the valve assembly is provided with a second closed connection flange (7), the first closed connection flange (6) is connected with the second closed connection flange (7) and a second sealing device is arranged at the joint surface, so that the cavity part outside the first sealing device in the valve assembly and the inner cavity part of the actuator assembly are communicated to become a closed cavity; The actuator assembly is further provided with a detection device (3) for detecting the leakage of the medium in the inner cavity of the actuator assembly; The actuator assembly is further provided with a leakage discharge device (8) communicated with the inner cavity of the actuator assembly.

2. The hermetically sealed, leak-proof motorized valve of claim 1, wherein: The actuator assembly comprises a base (2), a manual shaft (10) is rotatably connected to the base (2), and the manual shaft (10) is in transmission connection with an output shaft of the actuator assembly; A manual sealing mechanism (5) is arranged at the manual shaft (10).

3. The fully enclosed, leak-proof motorized valve of claim 2, wherein: The manual sealing mechanism (5) comprises a third sealing device arranged between the manual shaft (10) and the base (2), and / or a sealing blind cap (501) arranged on the base (2) and covering the outer end of the manual shaft (10).

4. The fully enclosed, leak-proof motorized valve of claim 3, wherein: A first circular boss is arranged on the base (2), an aperture is formed in the first circular boss, and the manual shaft (10) passes through the aperture; The third sealing device comprises a first sealing ring (502) arranged on the manual shaft (10) and in contact with the inner wall of the aperture; The third sealing device further comprises a second sealing gasket (503) arranged between the annular protrusion at the inner end of the manual shaft (10) and the inner wall of the base (2); The sealing blind cap (501) is in threaded connection with the first circular boss, and a third sealing gasket (504) is further arranged between the inner wall of the sealing blind cap (501) and the end surface of the first circular boss.

5. The hermetically sealed, leak-proof motorized valve as claimed in claim 1 or 2 or 3 or 4, wherein: A pressure-bearing terminal block (4) is further arranged outside the actuator assembly, the pressure-bearing terminal block (4) is used for realizing electrical connection between internal electrical components of the actuator assembly and external electrical components, and the pressure-bearing terminal block (4) is in sealed connection with the actuator assembly.

6. The fully enclosed, leak-proof motorized valve of claim 1, wherein: The detection device (3) is a medium pressure detection device, a medium component detection device or a medium conductivity detection device.

7. The fully enclosed leak-proof motorized valve as claimed in claim 1 or 2 or 3 or 4 or 5 wherein: The leakage discharge device (8) comprises a connecting seat (801), a leakage discharge valve core (802), a sealing head (808), a sealing cap (809), a spring (806), a second sealing ring (803) and a fourth sealing gasket (807); The connecting seat (801) is arranged on the base (2), and the connecting seat (801) is provided with a first central hole, a second central hole and a third central hole connected in sequence from inside to outside; The inner diameter of the second central hole is smaller than that of the first central hole and the third central hole; The leakage discharge valve core (802) comprises a rod part and a head part connected with the inner end of the rod part; The diameter of the head part is greater than the inner diameter of the second central hole and smaller than the inner diameter of the first central hole; The outer end of the rod part is provided with a central blind hole (805), and the rod part is provided with a side hole (804) communicated with the central blind hole (805) near the head part. The rod part is in sliding fit with the second center hole, the head part is in the first center hole, the second sealing ring (803) is sleeved outside the rod part and between the head part and the side hole (804); the sealing head (808) is in the third center hole and connected with the outer end of the rod part, a center through hole is arranged in the sealing head (808) and communicates with the center blind hole (805); the spring (806) is arranged in the third center hole and used for pushing the sealing head (808) and the leakage valve core (802) outward; the fourth sealing gasket (807) is arranged between the sealing head (808) and the outer end surface of the connecting seat (801); the sealing cap (809) is connected with the connecting seat (801) through threaded fit, used for pressing the sealing head (808) and the fourth sealing gasket (807) inward, and in the pressing state, the outer edge of the fourth sealing gasket (807) is in contact with the inner wall of the sealing cap (809).

8. The fully enclosed, leak-proof motorized valve of claim 7, wherein: The leakage device (8) further comprises a sealing connector (810), the inner end of the sealing connector (810) is used for being connected with the connecting seat (801) through threaded fit, and the outer end is used for connecting a leakage pipeline (811).

9. The fully enclosed, leak-proof motorized valve of claim 1, wherein: The fourth sealing device is further arranged between the output shaft (13) and the shaft hole in the bottom of the base (2) for passing the output shaft (13), so as to block the fluid leaked from the first sealing device from entering the inside of the actuator assembly.

10. A method of early warning and leak elimination of a fully enclosed leak-proof electrically operated valve according to any one of claims 1 to 9, characterized in that: The leakage state detected by the real-time monitoring and detecting device (3) is monitored, if the state reaches a preset threshold, a pre-warning signal is sent, and maintenance is prompted, the leakage device (8) is opened before maintenance, and the fluid entering the inner cavity of the actuator assembly is discharged, and the leakage method is as follows: first, the sealing cap (809) is removed, at this time, the leakage valve core (802) is pushed outward under the action of the spring (806), until the head part extrudes the second sealing ring (803), so that the latter is in contact with the outer end surface of the first center hole, at this time, the fluid in the inside is temporarily blocked outside the side hole (804), and temporary sealing is realized; then, the sealing connector (810) is installed and connected with the leakage pipeline (811), after the sealing connector (810) is tightened, the sealing head (808) and the fourth sealing gasket (807) are pressed again, so that the fluid passage is opened, the leaked fluid can enter the center blind hole (805) from the side hole (804), and is guided to a designated collecting device through the sealing connector (810) and the leakage pipeline (811).

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