A self-priming centrifugal pump

Abstract

The present invention discloses a self-priming centrifugal pump, comprising: a pump body, an impeller assembly, driven to rotate by an impeller shaft, the axis of the impeller shaft being arranged below the axis of the flow channel opening with the axis of the impeller shaft offset; a flow channel body, sealedly connected to the flow channel opening and the impeller assembly, provided with a return flow channel body communicating with a pump chamber, a return flow stopper being provided inside the flow channel body opposite the return flow channel body's return outlet, the return flow stopper being arranged below the axis of the impeller shaft with the axis offset; the return flow stopper extending toward one end of the impeller assembly and forming a return flow guide channel between the inner wall of the flow channel body; and a return valve assembly, the return valve assembly being arranged inside the return flow channel body and extending outside the pump body, the return valve assembly being provided with a self-priming function locking structure. The self-priming centrifugal pump has fast reflux, short self-priming time, and good self-priming performance. It has a self-priming function when turned on and can be locked when in normal working state.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal pumps, in particular to a self-priming centrifugal pump with a reflux valve switching function. Background Art

[0002] The existing self-priming centrifugal pump adopts an internal mixing self-priming structure. During the self-priming process, the reflux valve opens, and the water in the pump chamber flows through the reflux valve to the impeller inlet, where the gas and liquid are mixed and then discharged into the pump chamber for gas-liquid separation. The gas is discharged upward through the pump outlet, and the liquid returns to the inlet through the reflux valve. This cycle is repeated until the gas in the pump body and the inlet pipeline is exhausted and the pump works normally. At this time, the reflux valve is closed under the action of water pressure.

[0003] However, existing self-priming centrifugal pumps suffer from a serious discrepancy between their self-priming function and design requirements due to suboptimal design of the flow diversion and internal reflux structures. This results in a performance degradation, reduced lift, and increased noise. To prevent the return valve from closing during the self-priming process, the valve's closing pressure is typically set at approximately 10m lift. Therefore, when the pump is operating normally, the return valve will open even when the lift is less than 10m, allowing high-pressure water in the pump chamber to leak back to the impeller inlet, severely degrading pump performance and potentially generating noise and cavitation. There's also the risk of the return valve becoming stuck with impurities in the water and unable to close.

[0004] At the same time, the reflux valve structure is only used to complete the self-priming process. Generally, self-priming is only required when the water pump is just installed, but the self-priming function does not need to be started during normal use. The reflux valve of the self-priming pump in the prior art is in an automatically controlled open state. When the water and gas in the pipeline are uncertain during normal use, the pressure difference will change, and the self-priming function will automatically start, which will lead to a decrease in the performance and lift of the pump, and will also cause greater noise.

[0005] Therefore, it is urgent to design a self-priming centrifugal pump with a reflux valve switching function. When self-priming, the self-priming effect is good and the water-gas separation is fast. Under normal working conditions, the self-priming function is closed, which can ensure the performance and lift of the pump. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems of slow reflux speed and unsatisfactory self-priming effect of existing self-priming centrifugal pumps, and when the pump is working normally, the reflux valve is affected by the water pressure and head in the pipeline, which causes the reflux valve to start frequently or the reflux valve cannot be completely closed due to impurities in the water, thereby seriously affecting the performance of the pump and causing noise, cavitation and other problems. The present invention provides a self-priming centrifugal pump with good self-priming effect, fast reflux speed, short air-water separation time, and can effectively solve the problem that the reflux valve cannot be completely closed when the pump is working normally, can effectively improve the performance of the pump, reduce the occurrence of noise and cavitation, and avoid the risk of jamming.

[0007] The technical solution adopted by the present invention to achieve its invention object is: a self-priming centrifugal pump, comprising:

[0008] A pump body, wherein the pump body is provided with a water inlet and a water outlet, and the pump body is provided with a flow channel opening connected to the water inlet and a pump cavity connected to the water outlet;

[0009] An impeller assembly is disposed inside the pump chamber and is driven to rotate by an impeller shaft, wherein the axis of the impeller shaft deviates from the axis of the flow channel opening and is disposed below the axis of the flow channel opening;

[0010] A flow channel body, sealed with the flow channel opening and the impeller assembly, and used to form an internal guide channel and a return channel. The flow channel body is provided with a return flow channel body connected to the pump chamber. A return flow stopper is provided inside the flow channel body, facing the return flow outlet of the return flow channel body. The return flow stopper is offset from the axis of the impeller shaft and is provided below the axis of the impeller shaft. The return flow stopper extends toward one end of the impeller assembly and forms a return flow guide channel between the inner wall of the flow channel body.

[0011] The reflux valve assembly is a modular assembly used to realize self-priming opening and closing locking; the reflux valve assembly is arranged inside the reflux flow channel body and extends to the outside of the pump body, and the reflux valve assembly is provided with a self-priming function locking structure.

[0012] The self-priming centrifugal pump adopts a completely new design of the pump body, flow channel body and return valve assembly, so that the axis of the impeller shaft deviates from the axis of the flow channel opening and is arranged below the axis of the flow channel opening, thereby forming a stepped structure between the flow channel opening and the end face of the impeller shaft. The high-pressure water entering from the water inlet of the pump body will not directly impact the end of the impeller shaft during the process of flowing through the flow channel opening to the impeller. In other words, the high-pressure water and the gas inside will not directly impact the end face of the impeller shaft, thereby avoiding the problem that the gas is not easy to enter the impeller assembly during the self-priming process, resulting in poor self-priming performance. The arrangement of this structure also prevents the backflowing water from entering the flow channel opening during self-priming, making the self-priming process of the pump more stable. At the same time, in order to further improve the self-priming performance, a reflux stopper is provided inside the flow channel body at the reflux outlet of the reflux flow channel body, and a reflux guide channel is formed inside the flow channel body through the reflux stopper, and the reflux guide channel is located below the axis of the impeller shaft. Such a structure enables the reflux water and gas to quickly and conveniently enter the impeller assembly through the reflux guide channel during the reflux process for gas-water mixing and then separation, which not only blocks the direct impact of the high-pressure water entering the water inlet of the pump body on the reflux water and gas, reduces the influence of the pressure difference on the self-priming reflux, but also facilitates the reflux water and gas to quickly enter the impeller assembly, thereby improving the self-priming reflux performance and shortening the self-priming time. More importantly, this self-priming centrifugal pump addresses the problem that the self-priming function is only required when the installation is completed and the startup is started, but not during the normal operation of the pump. By providing a return valve assembly with a self-priming function locking structure, the pump has a self-priming function when it is turned on, and the self-priming function can be locked when the pump enters the normal working state, thereby avoiding the frequent opening of the return valve due to the reduction of water pressure and head in the pipeline under the normal working state of the pump, which leads to the performance degradation of the pump and the risks of noise, cavitation, and the inability to close the return valve.

[0013] Preferably, the reflux valve assembly includes a valve seat, a valve body assembly, a movable block and an adjusting locking piece integrated inside the reflux flow channel body, the valve seat is integrally arranged inside the reflux flow channel body, the valve body assembly cooperates with the valve seat in an opening and closing manner, the movable block is slidably connected to the valve body assembly, and the adjusting locking piece is adjustably connected to the pump body. The reflux valve assembly includes a valve seat, a valve body assembly, a movable block and an adjusting locking piece integrated inside the flow channel body, the valve seat is integrally arranged inside the reflux flow channel body. Such a structure not only facilitates the integrated setting of the reflux valve body and the flow channel body, but also facilitates the modular setting of the reflux valve assembly, so that the reflux valve assembly can be easily and quickly assembled and disassembled. By disassembling the modular reflux valve assembly, the function of emptying the liquid in the pump chamber can be realized, and the valve body assembly can be disassembled for cleaning to avoid blockage.

[0014] Preferably, the locking structure includes a 90-degree rotation locking slot provided on the movable block and a movable slot provided on the adjusting locking member. The self-priming function locking structure adopts the cooperation of a movable block and an adjusting locking piece. Specifically, a locking groove with an I-shaped structure is provided on the movable block, and a movable groove cooperating with the movable block is provided on the surface adjusting locking piece. When the reflux valve is in the self-priming state, the movable block can move up and down along the movable groove. When it is necessary to lock the self-priming function, the movable block can be automatically or manually pushed upward to drive the valve core to move upward to close the reflux channel. At this time, the movable block is rotated 90 degrees so that the locking groove on the movable block and the movable groove on the adjusting locking piece are connected at 90 degrees, thereby limiting the up and down movement of the movable block, thereby achieving the purpose of locking the self-priming function of the reflux valve, so that the pump will not start the self-priming function step by step due to the reduction of water pressure or head in the pipe during normal operation, effectively improving the performance of the pump, reducing noise and cavitation. At the same time, it also avoids the occurrence of the reflux valve being unable to be completely closed and stuck due to impurities in the water.

[0015] Preferably, the valve body assembly includes a spring and a valve core. One end of the return spring is sleeved inside the valve seat and the other end is sleeved on the valve core. The valve core is provided with an opening and closing seal. A number of valve core blades for forming a return channel are evenly distributed on the outer circumference of the valve core. The valve core is integrally provided with a valve stem downward. The valve body assembly mainly includes a spring and a valve core. The spring is installed between the valve seat and the valve core to achieve a rebound effect. Specifically, when the pump is in a self-priming state, due to the action of the spring, the return channel between the valve core and the valve seat is opened, and the water and gas inside the pump chamber enter the return flow guide channel through the return channel, and then enter the impeller assembly for centrifugal separation by the impeller. When the water pressure inside the valve chamber is greater than the elastic force of the spring, the water pressure pushes the valve core upward, so that the valve core and the valve seat cooperate to close the return channel. At this time, the pump operates normally. The opening and closing seal on the valve core is to ensure the sealing effect when the return valve is closed, thereby improving the performance of the pump. The purpose of setting the valve stem downward as an integral part of the valve core is to cooperate with the movable block in a sliding manner. The valve core can be pushed upward by pushing the movable block to achieve cooperation and closure with the valve seat, thereby realizing the locking structure of the self-priming function of the movable block to lock the self-priming function of the return valve, ensuring that the pump is in normal working condition, and the return valve will not be frequently started due to changes in water pressure and head, affecting the performance of the pump.

[0016] Preferably, the movable block includes an integrally arranged valve stem socket, a sealing body, and a locking body. The valve stem socket is internally provided with a plug-in sliding cavity, the outer annular surface of the sealing body is provided with a sealing groove, a sliding seal is provided within the sealing groove, the locking body is provided with an I-shaped structure, and the locking slot is symmetrically arranged on the locking body. The movable block is integrally provided with the valve stem socket to facilitate the sliding insertion of the valve stem and to push the valve core upward through the movable block. The sealing body is provided to facilitate the cooperation with the pump body's movable seal, and the locking body is provided to facilitate the setting of the locking slot, thereby achieving a clamping limit between the adjustable locking member.

[0017] Preferably, the adjusting locking member is provided with an annular cover structure, an adjusting internal thread is provided inside the adjusting locking member, the movable slot is provided on the end face of the adjusting locking member, and locking positions are provided on both sides of the movable slot. The adjusting locking member is used to achieve the locking of the self-priming function of the reflux valve in cooperation with the movable block, and secondly, to achieve an adjustable connection with the pump body for adjusting the reflux valve, and thirdly, to achieve the function of a drain valve. When it is necessary to empty the liquid inside the pump chamber, the adjusting locking member can be opened for discharge, and the reflux valve assembly can also be disassembled and cleaned to prevent blockage. The locking positions are provided on both sides of the movable slot to facilitate the positioning of the locking slot on the movable block in the locked state.

[0018] Preferably, the flow channel body further comprises an integrally arranged water inlet flow channel body and an impeller flow channel body, the water inlet flow channel body is sealed and docked with the flow channel port, the impeller flow channel body is sealed and docked with the impeller assembly, and the return flow channel body and the impeller flow channel body are arranged in a vertical structure. The flow channel body mainly comprises an integrally arranged water inlet flow channel body, an impeller flow channel body and a return flow channel body, and the water inlet flow channel body is sealed and connected with the flow channel port for directing the pressurized water at the water inlet to the impeller assembly, and the impeller flow channel body is for sealing and docking with the impeller assembly, and at the same time forms a fluid channel with a stepped drop structure with the water inlet flow channel body, so that the pressurized water inside the fluid channel will not directly impact the end face of the impeller shaft, so that water and gas can quickly enter the impeller assembly. With such a structure, the refluxed water will not enter the water inlet flow channel body during self-priming, making the self-priming process of the pump more stable. At the same time, the return flow channel body and the impeller flow channel body are arranged in two mutually perpendicular directions to ensure that the return water and gas in the self-priming reflux process can be separated from the water and gas inside the fluid channel and quickly enter the impeller assembly for water-gas mixing, achieving rapid water-gas separation, improving self-priming performance and pump performance. The return flow channel body is arranged in a vertical structure because this design structure ensures that gas and water enter the return flow channel in sequence, and can more quickly draw the internal gas and water into the impeller assembly for water-gas separation after mixing.

[0019] Preferably, the impeller assembly includes a guide vane, an impeller body and an impeller casing, the guide vane includes a guide vane water inlet and a guide vane casing, the guide vane water inlet is sealed with the flow channel body, the guide vane casing and the impeller casing cooperate to form an impeller working chamber, and a plurality of guide vane water outlets are provided on the guide vane casing; the guide vane water outlet is connected to the pump chamber; the impeller body is fixed on the impeller shaft and is arranged inside the impeller working chamber, and the annular surface where the impeller mouth ring on the impeller body is located is located in the center of the return flow guide channel in the horizontal direction. The impeller assembly mainly includes guide vanes, an impeller body, and an impeller housing. The impeller guide vanes are provided to achieve a sealed connection with the impeller flow channel body, thereby forming a fluid channel. The fluid channel is connected to the impeller mouth ring to facilitate the rapid passage of gas and water. Secondly, by setting a guide vane outlet on the impeller guide vane, the gas and water separated by the impeller centrifugation can be discharged from the outlet. Under normal working conditions, the overall performance of the pump can be guaranteed, and it can always ensure that it works within the set head range. The water flow after the centrifugal action of the impeller is introduced into the pump cavity through the guide vane outlet and then transported out from the pump outlet. The annular surface of the impeller mouth ring on the impeller body is located in the center of the return flow guide channel in the horizontal direction. This design structure is to ensure that the gas and return water can quickly enter the impeller mouth ring without being impacted by the water pressure during the self-priming process, so that they can be quickly mixed and separated through the centrifugal action of the impeller, thereby improving the overall performance of the pump.

[0020] Preferably, the impeller ring and the guide vane water inlet form an inlet cavity, which is provided to achieve a rapid flow diversion effect.

[0021] Preferably, the water outlet on the pump body is arranged at an angle of 90 degrees to the water inlet, the axis of the flow channel port deviates from the axis of the water inlet, and the flow channel port and the water inlet form a stepped drop structure; the axis of the reflux valve assembly is arranged parallel to the axis of the water outlet, and the axis of the reflux valve assembly deviates toward the water inlet. A stepped drop structure is formed between the water inlet and the flow channel port of the pump body. Such a structure can ensure that the pump chamber can accommodate more water when filling water before self-priming, and the refluxed water will not enter the inlet pipe during self-priming, making the self-priming process of the pump smoother and the self-priming performance of the pump can be greatly improved. The axis of the reflux valve assembly deviates toward the water inlet. Such a structural setting can provide a smoother reflux channel for gas and reflux water, allowing gas and water to be quickly introduced into the impeller ring without causing a reduction in self-priming performance due to an unreasonable reflux structure.

[0022] The beneficial effects of the present invention are as follows: the self-priming centrifugal pump has fast reflux, short self-priming time and good self-priming performance. By providing a reflux valve assembly with a self-priming function locking structure, the pump has a self-priming function when opened, and the self-priming function can be locked when the pump enters a normal working state, thereby avoiding the frequent opening of the reflux valve due to the reduction of water pressure and head in the pipeline under the normal working state of the pump, which leads to the performance degradation of the pump and the risks of noise, cavitation, and the inability to close the reflux valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of the self-priming centrifugal pump of the present invention;

[0024] Figure 2 It is a cross-sectional view of the self-priming centrifugal pump of the present invention;

[0025] Figure 3 This is an exploded view of a half-sectioned self-priming centrifugal pump of the present invention;

[0026] Figure 4 This is a schematic diagram of the exploded structure of the reflux valve assembly of the present invention;

[0027] Figure 5 1. It is a structural schematic diagram of the self-priming centrifugal pump of the present invention in a normal working state (self-priming function is not locked);

[0028] Figure 6 This is a structural diagram of the guide vane in the present invention;

[0029] Figure 7 1. It is a structural schematic diagram of the self-priming centrifugal pump of the present invention in a normal working state (self-priming function locked);

[0030] In the figure: 1. Pump body, 11. Water inlet, 12. Flow channel outlet, 13. Water outlet, 14. Pump chamber, 15. Reflux valve assembly installation port;

[0031] 2. Impeller assembly, 21. Guide vane, 211. Guide vane water inlet, 212. Guide vane housing, 213. Guide vane water outlet, 22. Impeller body, 221. Impeller mouth ring, 23. Impeller housing;

[0032] 3. Impeller shaft;

[0033] 4. Flow channel body, 41. Return flow channel body, 42. Return outlet, 43. Return stopper body, 44. Water inlet flow channel body, 45. Impeller flow channel body;

[0034] 5. diversion channel, 6. return channel, 7. return diversion channel;

[0035] 8. Reflux valve assembly, 80. Valve seat, 81. Valve body assembly, 82. Movable block, 821. Locking slot, 822. Valve stem socket, 823. Sealing body, 824. Locking body, 825. Inserting sliding cavity, 826. Sealing groove, 827. Sliding seal, 83. Adjusting locking member, 831. Movable slot, 832. Adjusting internal thread, 833. Locking position, 84. Sealing valve face, 85. Spring, 86. Valve core, 87. Opening and closing seal, 88. Valve core blade, 89. Valve stem;

[0036] 9. Impeller working chamber, 10. Inlet chamber;

[0037] L1, axis of the water inlet, L2, axis of the flow channel outlet, L3, axis of the return valve assembly installation port, L4, axis of the water outlet, L5, axis of the impeller shaft. DETAILED DESCRIPTION

[0038] The various aspects of the present invention are described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0039] Example 1:

[0040] exist Figure 1 、 Figure 2 、 Figure 3 In the embodiment shown, a self-priming centrifugal pump having a self-priming locking function specifically includes:

[0041] The pump body 1 is provided with a flow channel opening 12 connected with the water inlet 11 and a pump cavity 14 connected with the water outlet 13; the pump body is provided with a water inlet 11 and a water outlet 13, the water inlet 11 and the water outlet 13 are arranged vertically at 90 degrees, a pump cavity 14 is provided inside the pump body 1, a flow channel opening 12 is provided inside the pump cavity 14, the flow channel opening 12 is provided below the water inlet 11 and the water inlet 11 and the flow channel opening 12 are arranged in a stepped structure, the axis L1 of the water inlet is parallel to the axis L2 of the flow channel opening and a constricted flow channel is formed between the water inlet 11 and the flow channel opening 12, so as to facilitate the formation of water inlet pressure. A stepped structure is formed between the water inlet and the flow channel of the pump body. This structure ensures that the pump chamber can accommodate more water when filling before self-priming, and the water flowing back during self-priming will not enter the inlet pipe, making the self-priming process of the pump more stable and greatly improving the self-priming performance of the pump. A reflux valve assembly mounting port 15 is vertically provided on the pump body 1 opposite to the water outlet 11. The axis L3 of the reflux valve assembly mounting port is arranged parallel to and not coaxial with the axis L4 of the water outlet, and the axis L3 of the reflux valve assembly mounting port deviates toward the water inlet 11.

[0042] The impeller assembly 2 is arranged inside the pump chamber 14 and is driven to rotate by an impeller shaft 3. The axis L5 of the impeller shaft deviates from the axis L2 of the flow channel opening and is arranged below the axis L2 of the flow channel opening; the axis of the impeller shaft deviates from the axis of the flow channel opening and is arranged below the axis of the flow channel opening, thereby forming a stepped structure between the flow channel opening and the end face of the impeller shaft. When high-pressure water enters the water inlet of the pump body, it will not directly impact the end of the impeller shaft during the process of flowing through the flow channel opening to the impeller. In other words, the high-pressure water and the gas inside will not directly impact the end face of the impeller shaft, thereby avoiding the problem of gas not easily entering the impeller assembly during the self-priming process, resulting in poor self-priming performance. At the same time, such a stepped structure prevents the backflowing water from entering the flow channel opening during self-priming, making the self-priming process of the pump more stable.

[0043] The flow channel body 4 is sealed with the flow channel opening 12 and the impeller assembly 2, and is used to form an internal guide channel 5 and a return channel 6. The flow channel body 4 is provided with a return flow channel body 41 that communicates with the pump chamber 14. A return flow stopper 43 is provided inside the flow channel body 4, facing the return flow channel body's return outlet 42. The return flow stopper 43 is offset from the impeller shaft axis L5 and is arranged below the impeller shaft axis L5. The return flow stopper 43 extends toward one end of the impeller assembly 2 and forms a return flow guide channel 7 with the inner wall of the flow channel body.

[0044] The reflux valve assembly 8 is a modular component for realizing self-priming opening and closing locking; the reflux valve assembly 8 is arranged inside the reflux flow channel body 41 and extends to the outside of the pump body 1, and the reflux valve assembly 8 is provided with a self-priming function locking structure.

[0045] The flow channel body 4 includes an integrally arranged water inlet flow channel body 44, an impeller flow channel body 45 and a return flow channel body 41. The water inlet flow channel body 44 is sealed and docked with the flow channel opening 12, the impeller flow channel body 45 is sealed and docked with the guide vane, and the return flow channel body 41 is arranged corresponding to the return valve assembly installation port 15.

[0046] The impeller assembly 2 includes a guide vane 21, an impeller body 22, and an impeller housing 23. The guide vane 21 includes a guide vane water inlet 211 and a guide vane housing 212. The guide vane water inlet 211 is sealed with the flow channel body 4. Specifically, the impeller flow channel body 45 is sealed with the inner wall of the guide vane water inlet 211 through a seal. The guide vane housing 212 cooperates with the impeller housing 23 to form the impeller working chamber 9. Figure 6As shown, the guide vane housing 212 is provided with a plurality of guide vane water outlets 213; the guide vane water outlets 213 are in communication with the pump chamber 14. The impeller body 22 is fixed to the impeller shaft 3 and disposed within the impeller working chamber 9. The annular surface of the impeller ring 221 on the impeller body 22 is horizontally located at the center of the return flow guide channel 7. The impeller ring 221 and the guide vane water inlet 211 form the inlet chamber 10.

[0047] The impeller housing 23 is sealed with the pump body 1 and forms an impeller working chamber 9 with the guide vane 21. The impeller body 22 is arranged inside the impeller working chamber 9. The impeller body 22 is driven to rotate inside the impeller working chamber 9 by the impeller shaft 3. The impeller body 22 is provided with an impeller mouth ring 221.

[0048] A reflux stopper 43 is provided directly above the reflux channel body 41. The reflux stopper 43 is provided on the side of the water inlet channel body 44 facing the reflux channel body 41, and the reflux stopper 43 is located below the axis of the impeller channel body (i.e., the axis L5 of the impeller shaft). The height between the lower wall of the reflux stopper 43 and the reflux outlet of the reflux channel body 41 is less than one-quarter of the impeller channel body diameter, i.e., the lower wall of the inlet cavity 10 is located at the center position of the height between the lower wall of the reflux stopper 43 and the reflux outlet 42 of the reflux channel body.

[0049] like Figure 4 As shown, the reflux valve assembly 8 includes a valve seat 80, a valve body assembly 81, a movable block 82 and an adjusting locking member 83 integrated in the reflux flow channel body 41. The valve seat 80 is integrally arranged in the reflux flow channel body 41. The reflux inlet end of the valve seat 80 is provided with a sealing valve surface 84. The valve body assembly 82 cooperates with the sealing valve surface 84 of the valve seat 80 in an opening and closing manner. The valve body assembly 81 includes a spring 85 and a valve core 86. One end of the spring 85 is sleeved on the valve seat 80, and the other end is sleeved on the valve core 86. An opening and closing seal 87 is provided at the cooperation position between the valve core 85 and the sealing valve surface 84 on the valve seat 80. A plurality of valve core blades 88 for forming a reflux channel are provided on the valve core 85, and a valve stem 89 is integrally provided downwardly of the valve core 85.

[0050] The self-priming function locking structure includes a 90-degree rotation locking slot 821 provided on the movable block 82 and a movable slot 831 provided on the adjustment locking member 83 .

[0051] The movable block 82 includes an integrally arranged valve stem socket 822, a sealing body 823 and a locking body 824. The valve stem socket 822 is provided with a plug-in sliding cavity 825. The outer ring surface of the sealing body 823 is provided with a sealing groove 826. The sealing groove 826 is provided with a sliding seal 827. The sliding seal 827 is slidingly sealed and connected to the inner wall of the reflux valve assembly mounting port 15. The locking body 824 is arranged in an I-shaped structure, and the locking slot 821 is symmetrically arranged on the locking body 824.

[0052] The adjusting locking member 83 is provided with an annular cover structure, and the adjusting locking member 83 is threadedly connected to the pump body 1. An external thread is provided on the pump body 1 where the reflux valve assembly mounting port 15 is located. Correspondingly, the adjusting locking member 82 is provided with an adjusting internal thread 832. The adjusting locking member 83 is provided with an active card slot 831 and a locking card position 833 for the movable block 82 to move up and down. The active card slot 31 is provided in conjunction with the locking body 824, and the locking card position 833 is provided in the active card slot 83. 1 has an arc-shaped structure on both sides of the groove wall. When the reflux valve needs to be locked, the movable block 82 rotates 90 degrees so that the locking groove 821 and the movable groove 831 on it engage with each other, thereby limiting the up and down movement of the movable block 82 and achieving the locking of the reflux valve. At this time, the reflux valve is permanently closed and no longer automatically opens, which can ensure the normal operation of the pump and solve the problem that when the pump is in normal working state, the reflux valve opens due to self-priming of the water pump or the head is less than the set head, reducing the performance of the pump and affecting the normal use of the pump. The adjusting locking member 83 is threadedly connected to the pump body 1. The reflux valve can be adjusted by adjusting the locking member 83, and the reflux valve assembly can also be disassembled and cleaned to avoid the occurrence of reflux valve blockage. The liquid in the pump chamber can also be emptied by adjusting the locking member as needed.

[0053] like Figure 2As shown, when the pump is initially started, the external water flows through the water inlet 11 on the pump body into the flow channel 12, through the guide channel 5, into the impeller mouth ring 221, and is driven to rotate by the impeller body and then enters the pump chamber 14. In the initial starting state, it is necessary to use the self-priming function to achieve the separation of gas and water. At this time, the reflux channel 6 in the reflux valve assembly 8 is opened, and the spring 85 is in a natural state. At this time, the valve core is separated from the valve seat, and the water inside the pump chamber passes through the reflux channel 6 formed between the valve core and the pump body and flows out to the reflux outlet 42 of the reflux flow channel body 41. At this time, due to the stopping effect of the reflux stop body 43, the gas and water flow quickly along the reflux guide channel 7. The reflux water quickly enters the inlet chamber 10, and then enters the impeller through the impeller mouth ring 221 for gas-liquid mixing. Since the reflux water passes through the stopping effect of the reflux stopper 43, the water flows downward and the gas flows upward. At the same time, since the reflux stopper 43 is arranged below the axis of the impeller shaft 3, there is no direct collision between the reflux water and the end face of the impeller shaft, but the reflux water directly flows back into the impeller mouth ring 221. The reflux speed is fast, and the gas-liquid mixing and separation effect is more significant. It can quickly realize self-priming start-up, saving self-priming start-up time. When self-priming is completed and the lift reaches the set height, the reflux valve is closed by the upward water pressure, and the pump operates normally.

[0054] like Figure 5 As shown, when the pump is in normal operation, the valve core 86 overcomes the elastic force of the spring under the action of water pressure and is pushed upward to cooperate with the valve seat seal, thereby closing the return channel 6. At this time, if the pressure or head of the water flow is at the set value, the valve core will always be sealed with the valve seat to maintain the normal operation of the pump. However, when the water pressure or head is less than the set value, the force exerted on the valve core is less than the elastic force of the spring, and the valve core will be separated from the seal of the valve seat under the action of the spring restoring force, thereby opening the return channel 6, and the pump will automatically start the self-priming function. If the pressure or head continues to be unstable, the pump will cause the self-priming function to be frequently started under normal working conditions, thereby causing a serious decline in pump performance, and at the same time, noise and cavitation will be generated. There is also a risk that the valve core will be stuck by impurities in the water and cannot be closed.

[0055] The maximum self-priming height of a self-priming centrifugal pump is 10.2 meters when calculated based on atmospheric pressure. However, due to actual losses, the self-priming height of most self-priming centrifugal pumps is around 8 meters. When the water pump is self-priming, the spring is in a free state (uncompressed). When self-priming is completed, the pressure in the pump chamber is about 8-10 meters. In this embodiment, the spring force is set at about 10-15 Newtons, which just compresses the spring. At this time, closing the reflux channel during the self-priming process can prevent water from leaking back from the self-priming reflux channel during water use, causing deviations in pump performance. Figure 7As shown, after the self-priming function of the pump is started and enters the normal working state, the valve core and the valve seat are sealed and matched, and the reflux channel 6 is closed. At this time, the movable block is automatically or manually controlled to move upward. When the movable block moves to the set position and the sliding plug-in is completed with the valve stem on the valve core, the movable block is rotated 90 degrees clockwise or counterclockwise so that the locking groove 821 on the movable block and the movable groove 831 on the adjusting locking member are mutually engaged, thereby locking the sealing state of the valve core and the valve seat, thereby realizing the normally closed setting of the reflux valve. At this time, when the water pressure or head in the pipeline changes, the self-priming function of the pump will not start automatically, and even low water pressure or low head will not affect the performance of the pump. There is no risk of the reflux valve being unable to be completely closed or being stuck due to impurities in the water.

[0056] The reflux valve assembly can be automatically closed by the setting of the movable block, or it can be manually closed permanently, reducing the impact of the reflux valve on the performance at low head and eliminating the noise caused by the frequent opening and closing of the reflux valve.

[0057] In this embodiment, when the water pump is self-priming, the valve core in the return valve assembly opens, the return channel is connected, and water can return to the impeller inlet through the return channel 6, the return guide channel 7, and the inlet chamber 10, thereby achieving self-priming. Self-priming in the initial state is required by the design of a self-priming centrifugal pump. When self-priming is completed and the head is greater than 10m, the return valve is closed by the upward water pressure, and the pump operates normally; however, when the pump is operating normally, when the water pressure decreases or the head is less than 10m, frequent self-priming is undesirable. Therefore, by designing a movable block, when the self-priming function is not required in the future, the movable block can be moved upward and rotated 90 degrees, so that the movable block and the adjustment locking member are engaged with each other, and the return valve assembly will be permanently closed, thereby achieving the self-priming function will not be automatically activated even at low water pressure or low head, effectively improving the performance of the pump, and using it safely and reliably without noise or cavitation.

[0058] The contents described in the embodiments of this specification are merely an enumeration of the implementation forms of the inventive concept. The protection scope of the inventive type should not be considered as being limited to the specific forms described in the embodiments. The protection scope of the inventive type also extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A self-priming centrifugal pump, characterized in that include: A pump body (1), wherein the pump body is provided with a water inlet (11) and a water outlet (13), and the pump body is provided with a flow channel opening (12) communicating with the water inlet (11) and a pump cavity (14) communicating with the water outlet (13); An impeller assembly (2) is disposed inside the pump chamber (14) and is driven to rotate by an impeller shaft (3), wherein the axis of the impeller shaft deviates from the axis of the flow channel opening and is disposed below the axis of the flow channel opening; A flow channel body (4) is sealedly connected to the flow channel opening (12) and the impeller assembly (2) and is used to form an internal guide channel (5) and a return channel (6); the flow channel body (4) is provided with a return flow channel body (41) communicating with the pump chamber (14); a return flow stopper (43) is provided inside the flow channel body (4) opposite to the return flow channel body's return outlet (42); the return flow stopper (43) is arranged below the axis of the impeller shaft, deviating from the axis of the impeller shaft; the return flow stopper (43) extends toward one end of the impeller assembly (2) and forms a return flow guide channel (7) with the inner wall of the flow channel body; A reflux valve assembly (8) is a modularly arranged assembly for realizing self-priming opening and closing locking; the reflux valve assembly (8) is arranged inside the reflux flow channel body (41) and extends outside the pump body (1); the reflux valve assembly (8) is provided with a self-priming function locking structure; The reflux valve assembly (8) comprises a valve body assembly (81), a movable block (82) and an adjusting locking member (83); the self-priming function locking structure comprises a 90-degree rotation locking groove (821) provided on the movable block (82) and a movable groove (831) provided on the adjusting locking member (83); the movable block (82) is slidably connected to the valve body assembly (81); and a sealing body (823) and a locking body (824) are provided on the movable block.

2. The self-priming centrifugal pump according to claim 1, characterized in that: The reflux valve assembly (8) further includes a valve seat (80) integrated in the interior of the reflux flow channel body (41). The valve seat (80) is integrally arranged in the interior of the reflux flow channel body (41). The valve body assembly (81) and the valve seat (80) cooperate in an opening and closing manner. The regulating locking member (83) is regulatedly connected to the pump body (1).

3. The self-priming centrifugal pump according to claim 2, characterized in that: The valve body assembly (81) includes a spring (85) and a valve core (86). One end of the spring (85) is sleeved on the valve seat (80) and the other end is sleeved on the valve core (86). The valve core (86) is provided with an opening and closing seal (87). A plurality of valve core blades (88) for forming a reflux channel are evenly distributed on the outer circumference of the valve core (86). The valve core (86) is integrally provided with a valve stem (89) downwardly.

4. The self-priming centrifugal pump according to claim 2, characterized in that: The movable block (82) further includes an integrally arranged valve stem socket (822), the valve stem socket (822) is provided with a plug-in sliding cavity (825) therein, the outer ring surface of the sealing body (823) is provided with a sealing groove (826), the sealing groove (826) is provided with a sliding seal (827), and the locking body (824) is provided in an I-shaped structure.

5. The self-priming centrifugal pump according to claim 1, characterized in that: The adjusting locking member (83) is provided in a ring-shaped cover structure, an adjusting internal thread (832) is provided inside the adjusting locking member (83), the movable slot (831) is provided on the end face of the adjusting locking member (83), and locking positions (833) are provided on both sides of the movable slot (831).

6. The self-priming centrifugal pump according to any one of claims 1 to 5, characterized in that: The flow channel body (4) further comprises an integrally arranged water inlet flow channel body (44) and an impeller flow channel body (45), wherein the water inlet flow channel body (44) is sealed and docked with the flow channel opening (12), the impeller flow channel body (45) is sealed and docked with the impeller assembly (2), and the return flow channel body (41) and the impeller flow channel body (45) are arranged in a vertical structure.

7. The self-priming centrifugal pump according to any one of claims 1 to 5, characterized in that: The impeller assembly (2) includes a guide vane (21), an impeller body (22) and an impeller housing (23); the guide vane (21) includes a guide vane water inlet (211) and a guide vane housing (212); the guide vane water inlet (211) is sealedly connected to the flow channel body (4); the guide vane housing (212) and the impeller housing (23) cooperate to form an impeller working chamber (9); a plurality of guide vane water outlets (213) are provided on the guide vane housing (212); the guide vane water outlets (213) are communicated with the pump chamber (14); the impeller body (22) is fixed on the impeller shaft (3) and is arranged inside the impeller working chamber (9); the annular surface of the impeller mouth ring (221) on the impeller body (22) is located at the center of the return flow guide channel (7) in the horizontal direction.

8. The self-priming centrifugal pump according to claim 7, characterized in that: The impeller mouth ring (221) and the guide vane water inlet (211) form an inlet cavity (10).

9. The self-priming centrifugal pump according to any one of claims 1 to 5, characterized in that: The water outlet (13) on the pump body (1) is arranged at an angle of 90 degrees to the water inlet (11); the axis of the flow channel opening (12) deviates from the axis of the water inlet (11); the flow channel opening (12) and the water inlet (11) form a stepped structure; the axis of the return valve assembly (8) is arranged parallel to the axis of the water outlet (13), and the axis of the return valve assembly (8) deviates toward the water inlet (11).

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