Combined check valve

Abstract

The invention relates to the technical field of check valves, and discloses a combined check valve which comprises a valve shell, two valve clack assemblies, two buffer sealing assemblies and a transmission assembly. The valve shell comprises a cavity, a water inlet runner and a water outlet runner. The two valve clack assemblies are arranged in the cavity, and each valve clack assembly comprises a valve clack body; the two buffer sealing assemblies are arranged on the sides, close to each other, of the water inlet flow channel and the water outlet flow channel correspondingly and comprise annular bases, first annular grooves communicating with the cavity are formed in the annular bases, first annular check rings are arranged in the first annular grooves, and annular buffer blocks matched with the corresponding valve clack bodies are slidably connected into the first annular grooves. A first elastic piece is arranged between the annular buffer block and the first annular check ring; and the transmission assembly is used for enabling the two valve clack bodies to rotate simultaneously. According to the check valve, impact force of the valve clack bodies can be absorbed, damage to the valve clack bodies is reduced, the valve clack bodies on the two sides are used for sealing the water inlet runner and the water outlet runner correspondingly, and the check effect is better.

Description

Technical Field

[0001] The present invention relates to the technical field of check valves, and more particularly to a combined check valve. Background Art

[0002] A check valve refers to a valve that automatically opens and closes the valve disc by relying on its own flow to prevent the backflow of the medium. It is mainly used in pipelines where the medium flows in one direction. Under the pressure of the fluid flowing in one direction, the valve disc opens. When the fluid flows in the opposite direction, the fluid pressure, the deadweight of the valve disc and the torsion spring close the valve disc on the valve seat, thereby cutting off the fluid. The main function of the check valve is to prevent the backflow of the medium, the reversal of the pump and the drive motor, and the discharge of the container medium. The combined swing check valve is a type of check valve. The water flow in the water inlet channel is controlled by rotating the valve disc to open and close. The valve disc can be a metal valve disc or a rubber-coated valve disc. The rubber-coated valve disc swing check valve is currently used in the chemical, pharmaceutical and other fields.

[0003] In the related art, when the existing valve disc rotates downward by its own gravity, it is easy to impact the water inlet flow channel after long-term use, which can easily cause damage to the valve housing and the valve disc, and further affect the air tightness of the check valve. To this end, we propose a combined check valve. Summary of the invention

[0004] The present invention provides a combined check valve, which solves the technical problem in the related art that a valve disc is prone to impact a water inlet channel after long-term use, thereby easily causing damage to the valve housing and the valve disc, thereby affecting the air tightness of the check valve.

[0005] The present invention provides a combined check valve, comprising: a valve housing, which comprises: a cavity, an inlet flow channel and an outlet flow channel respectively arranged on both sides of the cavity and connected to the cavity; two valve flap assemblies, which are both arranged in the cavity and are respectively used to control the water flow at the inlet flow channel and the outlet flow channel, the valve flap assembly comprising: a mounting seat fixedly connected to the cavity, a rotating shaft rotatably connected to the mounting seat, a rocker fixedly connected to the rotating shaft, and a valve flap body fixedly connected to the rocker; two buffer sealing assemblies, which are respectively arranged on the side where the inlet flow channel and the outlet flow channel are close to each other, and Corresponding one to one with the two valve flap assemblies, the buffer sealing assembly includes: an annular seat, a first annular groove communicating with the cavity is formed on the annular seat, a first annular retaining ring is arranged in the first annular groove, an annular buffer block cooperating with the corresponding valve flap body is slidably connected in the first annular groove, and at least one first elastic member is arranged between the annular buffer block and the first annular retaining ring; a transmission assembly is arranged in the cavity, and is used to transmit the movement of the valve flap assembly near the water inlet channel to the valve flap assembly near the water outlet channel, so that the two valve flap bodies rotate simultaneously.

[0006] As a further improvement of the present invention, a first mounting groove and a second mounting groove are respectively provided on the side where the water inlet channel and the water outlet channel are close to each other, and the two annular seats are respectively arranged in the first mounting groove and the second mounting groove.

[0007] As a further improvement of the present invention, in the radial direction of the annular seat, the size of the annular buffer block is the same as the size of the first annular groove, and in an initial state, part of the annular buffer block is outside the first annular groove, and the other part is inside the first annular groove.

[0008] As a further improvement of the present invention, a plurality of first elastic members are provided, and the plurality of first elastic members are distributed in an annular array about the axis of the annular seat.

[0009] As a further improvement of the present invention, the transmission assembly includes: a fixed seat, a first transmission shaft, a second transmission shaft and a third transmission shaft with axes parallel to each other rotatably connected on the fixed seat, a first bevel gear fixedly connected to the first transmission shaft, a worm wheel fixedly connected to the third transmission shaft, a pair of mounting plates are provided on the fixed seat, a worm matched with the worm wheel is rotatably connected between the two mounting plates, a second bevel gear matched with the first bevel gear is fixedly connected to the smooth rod part of the worm, a first pulley assembly is transmission-connected between the first transmission shaft and the second transmission shaft, a second pulley assembly is transmission-connected between the second transmission shaft and the rotating shaft near the water inlet channel, and a third pulley assembly is transmission-connected between the third transmission shaft and the rotating shaft near the water outlet channel.

[0010] As a further improvement of the present invention, the fixing seat is arranged close to the sealing cover.

[0011] As a further improvement of the present invention, the combined check valve also includes: a compensation component, which includes: a second annular groove opened in the annular seat and connected to the cavity and a plurality of transmission components, an annular sealing gasket being slidably connected in the second annular groove, and the plurality of transmission components are used to transmit the movement of the annular buffer block to the annular sealing gasket.

[0012] As a further improvement of the present invention, in the radial direction of the annular seat, the size of the annular sealing gasket is the same as the size of the second annular groove, and in an initial state, the annular sealing gasket is located inside the second annular groove.

[0013] As a further improvement of the present invention, the transmission component includes: a connecting groove opened inside the annular seat for connecting the first annular groove and the second annular groove, a transmission shaft is rotatably connected in the connecting groove, a transmission plate is fixedly connected to the transmission shaft, a first through hole is opened on the first annular retaining ring, a first transmission rod is arranged on the annular buffer block, the free end of the first transmission rod passes through the first through hole and selectively contacts with one end of the transmission plate, a second transmission rod is arranged on the annular sealing gasket, and the other end of the transmission plate selectively contacts with the free end of the second transmission rod.

[0014] As a further improvement of the present invention, a second annular retaining ring is arranged in the second annular groove, a second through hole is opened on the second retaining ring, a second elastic member is arranged between the second annular retaining ring and the annular sealing gasket, and the other end of the transfer plate passes through the second through hole to selectively contact the free end of the second transfer rod.

[0015] The beneficial effects of the present invention are:

[0016] 1. The present invention provides a valve flap assembly and a buffer sealing assembly at the water inlet flow channel and the water outlet flow channel respectively. Thus, when the valve flap body rotates downward to intercept the water flow, the buffer sealing assembly can be used to absorb the impact force of the valve flap body, thereby reducing the damage of the valve flap body. In addition, the valve flap bodies on both sides are used to seal the water inlet flow channel and the water outlet flow channel respectively, so that the check effect is better.

[0017] 2. The present invention can arrange a transmission component so that when the valve flap body at the water inlet channel rotates toward the inside of the cavity, the valve flap body near the water outlet channel can be driven to rotate toward the inside of the cavity at the same time, thereby reducing the interference of the valve flap body near the water outlet channel with the water flow. In addition, the cooperation of the worm gear can prevent the valve flap body near the water outlet channel from rotating freely.

[0018] 3. The present invention can further improve the sealing performance between the valve disc body and the corresponding annular seat by arranging a compensation component inside the annular seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional structural schematic diagram of a combined check valve according to an embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of a first front cross-sectional structure of a combined check valve according to an embodiment of the present invention;

[0021] Figure 3 yes Figure 2 The enlarged view of point A in the middle;

[0022] Figure 4 yes Figure 2The enlarged view of point B in the middle;

[0023] Figure 5 It is a schematic diagram of a second front cross-sectional structure of a combined check valve according to an embodiment of the present invention;

[0024] Figure 6 yes Figure 5 Enlarged view of point C in the middle;

[0025] Figure 7 It is a schematic diagram of a first side cross-sectional structure of a combined check valve according to an embodiment of the present invention;

[0026] Figure 8 It is a schematic diagram of a second side cross-sectional structure of a combined check valve according to an embodiment of the present invention;

[0027] Fig. 9 1 is a schematic diagram of a top cross-sectional structure of a combined check valve according to an embodiment of the present invention;

[0028] Fig.10 Schematic diagram of a top view of a three-dimensional cross-sectional structure of a combined check valve according to an embodiment of the present invention

[0029] Fig.11 yes Fig.10 Enlarged view of point D in the middle.

[0030] In the figure: 1, valve housing; 11, cavity; 12, water inlet channel; 121, first mounting groove; 13, water outlet channel; 131, second mounting groove; 14, mounting port; 15, sealing cover; 2, valve disc assembly; 21, mounting seat; 22, rotating shaft; 23, rocker; 24, valve disc body; 3, buffer seal assembly; 31, annular seat; 32, first annular groove; 33, first annular retaining ring; 331, first through hole; 34, annular buffer block; 341, first transmission rod; 35, first elastic member; 4, transmission assembly; 41, fixed seat; 42, first Transmission shaft; 43, second transmission shaft; 44, third transmission shaft; 45, first bevel gear; 46, second bevel gear; 47, worm; 48, worm wheel; 49, mounting plate; 401, first pulley assembly; 402, second pulley assembly; 403, third pulley assembly; 5, compensation assembly; 51, second annular groove; 52, annular sealing gasket; 521, second transmission rod; 53, transmission assembly; 531, connecting groove; 532, transmission shaft; 533, transmission plate; 54, second annular retaining ring; 541, second through hole; 55, second elastic member. DETAILED DESCRIPTION

[0031] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that the discussion of these embodiments is only to enable those skilled in the art to better understand and implement the subject matter described herein, and the functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the contents of this specification. Each example may omit, replace or add various processes or components as needed. In addition, the features described relative to some examples may also be combined in other examples.

[0032] like Figure 1-Figure 11 As shown, a combined check valve includes: a valve housing 1, two valve flap assemblies 2, two buffer seal assemblies 3 and a transmission assembly 4. The valve housing 1 mainly plays the role of installation and support, and can provide installation space and installation carriers for corresponding components. The valve flap assembly 2 mainly plays the role of interception. The buffer seal assembly 3 mainly plays the role of buffering and sealing. The transmission assembly 4 mainly plays the role of transmitting motion.

[0033] like Figure 2 As shown, the valve housing 1 includes a cavity 11, an inlet channel 12 and an outlet channel 13 which are respectively opened on both sides of the cavity 11 and connected to the cavity 11. Specifically, the inlet channel 12 and the outlet channel 13 are concentrically arranged, and water can enter the cavity 11 from the inlet channel 12, and then flow out through the outlet channel 13. The valve housing 1 is provided with an installation port 14 which is connected to the cavity 11, and the installation port 14 is opened at the top of the valve housing 1. The installation port 14 mainly provides an entrance for the installation of the internal components of the cavity 11, and the valve flap assembly 2 and the buffer sealing assembly 3 can be installed into the cavity 11 through the installation port 14. A sealing cover 15 is fixedly connected to the installation port 14, and the sealing cover 15 mainly plays a sealing role; the sealing cover 15 and the installation port 14 can be fixed by screws.

[0034] In addition, if Figure 2 and Figure 5 As shown, two valve flap assemblies 2 are arranged in the cavity 11, and are used to control the water flow at the water inlet channel 12 and the water outlet channel 13 respectively. That is, one valve flap assembly 2 is arranged near the water inlet channel 12, and the other valve flap assembly 2 is arranged near the water outlet channel 13. Specifically, the valve flap assembly 2 includes a mounting seat 21, a rotating shaft 22 is rotatably connected to the mounting seat 21, a rocker 23 is fixedly connected to the rotating shaft 22, and a valve flap body 24 is fixedly connected to the rocker 23. When in use, in the initial state, the two valve flap bodies 24 are in a vertical state under their own gravity and seal the corresponding water inlet channel 12 and the water outlet channel 13 respectively. When the water flows through the water inlet channel 12, the valve flap body 24 close to the water inlet channel 12 will be pushed open under the impact of water pressure, so that the valve flap body 24 will rotate upward, and drive the corresponding rotating shaft 22 to rotate through the rocker 23, so that the water can flow into the cavity 11 through the water inlet channel 12.

[0035] In addition, if Figure 2 , Figure 3 and Figure 6 As shown, the two buffer seal assemblies 3 correspond to the two valve flap assemblies 2 one by one, and are respectively arranged on the side where the water inlet channel 12 and the water outlet channel 13 are close to each other. That is to say, the two buffer seal assemblies 3 cooperate with the two valve flap assemblies 2 respectively to buffer the impact generated by the falling of the two valve flap bodies 24. Specifically, the buffer seal assembly 3 includes an annular seat 31, on which a first annular groove 32 communicating with the cavity 11 is opened, a first annular retaining ring 33 is fixedly connected in the first annular groove 32, an annular buffer block 34 cooperating with the corresponding valve flap body 24 is slidably connected in the first annular groove 32, and at least one first elastic member 35 is arranged between the annular buffer block 34 and the first annular retaining ring 33. It should be noted that the two annular seats 31 are respectively arranged on the side of the water inlet channel 12 and the water outlet channel 13 close to the cavity 11, and the two annular seats 31 are concentrically sealed with the corresponding water inlet channel 12 and the water outlet channel 13. In this way, when the valve flap body 24 descends, it will contact the annular buffer block 34, and the annular buffer block 34 will squeeze the first elastic member 35, so as to buffer the valve flap body 24, thereby increasing the service life of the valve flap body 24. The first elastic member 35 can be a spring or other suitable components. The material of the annular buffer block 34 can be rubber or other suitable materials.

[0036] As an optional embodiment, Figure 2 As shown, the first mounting groove 121 and the second mounting groove 131 are respectively provided on the side where the water inlet channel 12 and the water outlet channel 13 are close to each other, and two annular seats 31 are respectively arranged in the first mounting groove 121 and the second mounting groove 131. The first mounting seat 21 and the second mounting groove 131 can both play the role of installation. Specifically, one of the annular seats 31 is fixedly connected in the first mounting groove 121, and the inner diameter of the annular seat 31 is the same as the inner diameter of the water inlet channel 12. The other annular seat 31 is fixedly connected in the second mounting groove 131, and the inner diameter of the annular seat 31 is the same as the inner diameter of the water outlet channel 13, so that the connection between the water inlet channel 12 and the corresponding annular seat 31, and the connection between the water outlet channel 13 and the corresponding annular seat 31 can be smoother and reduce resistance. The first mounting groove 121 and the second mounting groove 131 and the corresponding annular seat 31 can be interference fit or other suitable connection methods.

[0037] As an optional embodiment, Figure 6As shown, in the radial direction of the annular seat 31, the size of the annular buffer block 34 is the same as that of the first annular groove 32. That is to say, the outer diameter of the annular buffer block 34 is the same as that of the first annular groove 32, and the inner diameter of the annular buffer block 34 is the same as that of the first annular groove 32, so that the sealing performance between the annular buffer block 34 and the first annular groove 32 can be improved, and the inner wall of the first annular groove 32 can also be used to limit the annular buffer block 34, so that the movement of the annular buffer block 34 can be more stable. In addition, in the initial state, part of the annular buffer block 34 is outside the first annular groove 32, and the other part is inside the first annular groove 32. In this way, the part of the annular buffer block 34 located outside the first annular groove 32 can be used to buffer the corresponding valve flap body 24, and the part of the annular buffer block 34 located inside the first annular groove 32 can also be used to seal the corresponding valve flap body 24, thereby reducing the water flow entering the first annular groove 32, and then protecting the first elastic member 35.

[0038] As an optional embodiment, Figure 8 As shown, a plurality of first elastic members 35 are provided, and the plurality of first elastic members 35 are distributed in a circular array about the axis of the annular seat 31. The circular array distribution of the plurality of first elastic members 35 can provide a plurality of supporting points for the annular buffer block 34, so that the force of the annular buffer block 34 can be more uniform, and the movement of the annular buffer block 34 can be more stable.

[0039] In addition, if Figure 2 , Figure 4 , Figure 5 , Figure 7 and Fig. 9 As shown, the transmission assembly 4 is disposed in the cavity 11, and is used to transmit the movement of the valve flap assembly 2 near the water inlet flow channel 12 to the valve flap assembly 2 near the water outlet flow channel 13, so that the two valve flap bodies 24 rotate simultaneously. In this way, when water flows through the water inlet flow channel 12 to push open the valve flap body 24 near the water inlet flow channel 12, the valve flap body 24 near the water outlet flow channel 13 can be rotated into the cavity 11 through the transmission assembly 4, so that the water in the cavity 11 can flow out through the water outlet flow channel 13.

[0040] Specifically, the transmission assembly 4 includes a fixed seat 41, and a first transmission shaft 42, a second transmission shaft 43, and a third transmission shaft 44, which are rotatably connected to the fixed seat 41 and have axes parallel to each other. The axes of the first transmission shaft 42, the second transmission shaft 43, and the third transmission shaft 44 can be arranged perpendicular to the axis of the water inlet flow channel 12. A first bevel gear 45 is fixedly connected to the first transmission shaft 42, a worm gear 48 is fixedly connected to the third transmission shaft 44, and a pair of mounting plates 49 are fixedly connected to the fixed seat 41. A worm 47 cooperating with the worm gear 48 is rotatably connected between the two mounting plates 49, and the axis of the worm 47 is arranged in a vertical direction. A second bevel gear 46 that cooperates with the first bevel gear 45 is fixedly connected to the smooth rod portion of the worm gear 47, a first pulley assembly 401 is connected between the first transmission shaft 42 and the second transmission shaft 43, a second pulley assembly 402 is connected between the second transmission shaft 43 and the rotating shaft 22 near the water inlet channel 12, and a third pulley assembly 403 is connected between the third transmission shaft 44 and the rotating shaft 22 near the water outlet channel 13.

[0041] When in use, when water flows through the water inlet channel 12 to push open the valve flap body 24 near the water inlet channel 12, the valve flap body 24 will rotate and drive the corresponding rotating shaft 22 to rotate through the rocker 23. The rotation of the rotating shaft 22 can drive the second transmission shaft 43 to rotate through the transmission of the second pulley assembly 402. The rotation of the second transmission shaft 43 can drive the first transmission shaft 42 to rotate through the transmission of the first pulley assembly 401. The rotation of the first transmission shaft 42 can drive the worm 47 to rotate through the cooperation of the first bevel gear 45 and the second bevel gear 46. The rotation of the worm 47 can drive the worm wheel 48 to rotate through the cooperation with the worm wheel 48. The rotation of the worm wheel 48 can drive the rotating shaft 22 near the water outlet channel 13 to rotate through the transmission of the third pulley assembly 403, and then drive the valve flap body 24 near the water outlet channel 13 to rotate toward the inside of the cavity 11, and the water can flow out from the water outlet channel 13 from the inside of the cavity 11. It should be noted that, since the valve flap bodies 24 on both sides rotate simultaneously, when the water flows into the cavity 11, the valve flap bodies 24 near the water outlet flow channel 13 are already in an open state. Moreover, through the cooperation of the worm gear 48 and the worm 47, the free rotation of the valve flap bodies 24 near the water outlet flow channel 13 can be prevented, thereby preventing water from flowing back. The two valve flap bodies 24 are used to seal the water inlet flow channel 12 and the water outlet flow channel 13 respectively, and the sealing effect is better.

[0042] It should be noted that the rotation direction of the thread of the worm 48 can be set to cooperate with the worm wheel 47 to achieve a required rotation direction.

[0043] As an optional embodiment, a shell may be provided on the fixing seat 41 , and some components of the transmission assembly 4 may be installed in the shell to protect some components of the transmission assembly 4 .

[0044] As an optional embodiment, Figure 2 and Figure 4 As shown, the fixing seat 41 is arranged close to the sealing cover 15. That is to say, the transmission assembly 4 is arranged close to the sealing cover 15, so that when in use, the transmission assembly 4 can be kept away from the water flow, which can reduce the interference with the water flow and protect the transmission assembly 4.

[0045] In addition, if Figure 2 , Figure 3 and Figure 6 As shown, the combined check valve further includes a compensation component 5, which is used to improve the sealing between the annular seat 31 and the corresponding valve disc body 24. The compensation component 5 includes: a second annular groove 51 opened in the annular seat 31 and connected to the cavity 11, and a plurality of transmission components 53, and the plurality of transmission components 53 can be distributed in an annular array about the axis of the corresponding annular seat 31. An annular sealing gasket 52 is slidably connected in the second annular groove 51, and the plurality of transmission components 53 are used to transmit the movement of the annular buffer block 34 to the annular sealing gasket 52. Specifically, the transmission assembly 53 includes: a connecting groove 531 provided inside the annular seat 31 for connecting the first annular groove 32 and the second annular groove 51, a transmission shaft 532 is rotatably connected in the connecting groove 531, a transmission plate 533 is fixedly connected to the transmission shaft 532, a first through hole 331 is provided on the first annular retaining ring 33, a first transmission rod 341 is fixedly connected to the annular buffer block 34, the axis of the first transmission rod 341 is parallel to the axis of the annular seat 31, and the free end of the first transmission rod 341 passes through the first through hole 331 and selectively contacts one end of the transmission plate 533. A second transmission rod 521 is provided on the annular sealing gasket 52, and the other end of the transmission plate 533 selectively contacts the free end of the second transmission rod 521, and the axis of the second transmission rod 521 is parallel to the axis of the annular seat 31.

[0046] It should be noted that, in the radial direction of the annular seat 31, the size of the annular sealing gasket 52 is the same as that of the second annular groove 51, which can improve the sealing performance between the annular sealing gasket 52 and the second annular groove 51 and reduce the water flow entering the second annular groove 51. In addition, in the initial state, the annular sealing gasket 52 is inside the second annular groove 51, so that when the valve flap body 24 rotates downward under its own gravity, it will directly contact the annular buffer block 34, thereby reducing the interference of the annular sealing gasket 52 on the contact between the valve flap body 24 and the annular buffer block 34, so that the annular buffer block 34 can better play a buffering role.

[0047] When in use, when the valve flap body 24 rotates downward under its own gravity, the valve flap body 24 will first contact the annular buffer block 34, and the annular buffer block 34 will be used to absorb the impact force of the valve flap body 24. After being compressed, the annular buffer block 34 will squeeze the first elastic member 35 and drive the first transmission rod 341 to move. The first transmission rod 341 will contact and squeeze one end of the transmission plate 533 during the movement. The transmission plate 533 will rotate around the axis of the transmission shaft 532 at this time. During the rotation, the other end of the transmission plate 533 will push the second transmission rod 521 to move. The movement of the second transmission rod 521 will drive the annular sealing gasket 52 to move to one side of the cavity 11, and then it can contact the corresponding valve flap body 24, and improve the sealing between the annular seat 31 and the corresponding valve flap body 24. The annular sealing gasket 52 can be made of rubber or other suitable flexible materials. When the valve flap body 24 rotates into the cavity 11, the corresponding annular buffer block 34 will be reset to its original position under the action of the first elastic member 35.

[0048] In addition, if Figure 5 and Figure 6 As shown, a second annular retaining ring 54 is fixedly connected in the second annular groove 51, a second through hole 541 is provided on the second retaining ring, a second elastic member 55 is provided between the second annular retaining ring 54 and the annular sealing gasket 52, and the other end of the transmission plate 533 passes through the second through hole 541 and selectively contacts the free end of the second transmission rod 521. The second elastic member 55 mainly plays a role of resetting. When the other end of the transmission plate 533 drives the annular sealing gasket 52 to move toward one side of the cavity 11 through the second transmission rod 521, the second elastic member 55 is stretched at this time. When the valve flap body 24 rotates into the cavity 11, the corresponding annular sealing gasket 52 will be reset to its original position under the action of the second elastic member 55. It is convenient for repeated use. It should be noted that the first elastic member 35 and the second elastic member 55 can both be springs, and of course, they can also be other suitable components.

[0049] The above describes an embodiment of the present embodiment, but the present embodiment is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present embodiment, ordinary technicians in this field can also make many forms, all of which are within the protection of the present embodiment.

Claims

1. A combined check valve, characterized in that: include: A valve housing (1) comprising: a cavity (11), and a water inlet channel (12) and a water outlet channel (13) respectively arranged on both sides of the cavity (11) and communicating with the cavity (11); Two valve flap assemblies (2), both of which are arranged in the cavity (11) and are used to control the water flow at the water inlet channel (12) and the water outlet channel (13), respectively, the valve flap assembly (2) comprising: a mounting seat (21) fixedly connected in the cavity (11), a rotating shaft (22) rotatably connected to the mounting seat (21), a rocker (23) fixedly connected to the rotating shaft (22), and a valve flap body (24) fixedly connected to the rocker (23); Two buffer seal assemblies (3), which are respectively arranged on the side of the water inlet flow channel (12) and the water outlet flow channel (13) close to each other, and correspond to the two valve flap assemblies (2) one by one, the buffer seal assembly (3) comprising: an annular seat (31), a first annular groove (32) communicating with the cavity (11) is formed on the annular seat (31), a first annular retaining ring (33) is arranged in the first annular groove (32), an annular buffer block (34) cooperating with the corresponding valve flap body (24) is slidably connected in the first annular groove (32), and at least one first elastic member (35) is arranged between the annular buffer block (34) and the first annular retaining ring (33); A transmission assembly (4) is arranged in the cavity (11) and is used to transmit the movement of the valve flap assembly (2) near the water inlet channel (12) to the valve flap assembly (2) near the water outlet channel (13), so that the two valve flap bodies (24) rotate simultaneously.

2. A combined check valve according to claim 1, characterized in that: A first mounting groove (121) and a second mounting groove (131) are respectively provided on the side where the water inlet channel (12) and the water outlet channel (13) are close to each other, and the two annular seats (31) are respectively arranged in the first mounting groove (121) and the second mounting groove (131).

3. A combined check valve according to claim 1, characterized in that: In the radial direction of the annular seat (31), the size of the annular buffer block (34) is the same as the size of the first annular groove (32), and in an initial state, part of the annular buffer block (34) is located outside the first annular groove (32) and the other part is located inside the first annular groove (32).

4. A combined check valve according to claim 1, characterized in that: A plurality of the first elastic members (35) are provided, and the plurality of the first elastic members (35) are distributed in an annular array about the axis of the annular seat (31).

5. A combined check valve according to claim 1, characterized in that: The transmission assembly (4) comprises: a fixed seat (41), a first transmission shaft (42), a second transmission shaft (43) and a third transmission shaft (44) rotatably connected to the fixed seat (41), the first transmission shaft (42) being fixedly connected to a first bevel gear (45), the third transmission shaft (44) being fixedly connected to a worm gear (48), a pair of mounting plates (49) being provided on the fixed seat (41), a worm (47) cooperating with the worm gear (48) being rotatably connected between the two mounting plates (49), the worm gear (47) being arranged on the fixed seat (41) and the worm gear (47) being arranged on the fixed seat (41). A second bevel gear (46) cooperating with the first bevel gear (45) is fixedly connected to the light rod portion of the transmission shaft (7); a first pulley assembly (401) is transmission-connected between the first transmission shaft (42) and the second transmission shaft (43); a second pulley assembly (402) is transmission-connected between the second transmission shaft (43) and the rotating shaft (22) near the water inlet channel (12); and a third pulley assembly (403) is transmission-connected between the third transmission shaft (44) and the rotating shaft (22) near the water outlet channel (13).

6. A combined check valve according to claim 5, characterized in that: The fixing seat (41) is arranged close to the sealing cover (15).

7. A combined check valve according to claim 1, characterized in that: The combined check valve further comprises: a compensation component (5), which comprises: a second annular groove (51) opened in the annular seat (31) and connected to the cavity (11) and a plurality of transmission components (53), an annular sealing gasket (52) being slidably connected in the second annular groove (51), and the plurality of transmission components (53) being used to transmit the movement of the annular buffer block (34) to the annular sealing gasket (52).

8. A combined check valve according to claim 7, characterized in that: In the radial direction of the annular seat (31), the size of the annular sealing gasket (52) is the same as the size of the second annular groove (51), and in an initial state, the annular sealing gasket (52) is located inside the second annular groove (51).

9. A combined check valve according to claim 7, characterized in that: The transmission component (53) comprises: a connecting groove (531) provided inside the annular seat (31) for connecting the first annular groove (32) and the second annular groove (51); a transmission shaft (532) is rotatably connected in the connecting groove (531); a transmission plate (533) is fixedly connected to the transmission shaft (532); a first through hole (331) is provided on the first annular retaining ring (33); a first transmission rod (341) is provided on the annular buffer block (34); a free end of the first transmission rod (341) passes through the first through hole (331) and selectively contacts one end of the transmission plate (533); a second transmission rod (521) is provided on the annular sealing gasket (52); the other end of the transmission plate (533) selectively contacts the free end of the second transmission rod (521).

10. A combined check valve according to claim 9, characterized in that: A second annular retaining ring (54) is arranged in the second annular groove (51), a second through hole (541) is opened on the second retaining ring, a second elastic member (55) is arranged between the second annular retaining ring (54) and the annular sealing gasket (52), and the other end of the transfer plate (533) passes through the second through hole (541) to selectively contact the free end of the second transfer rod (521).

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