A small self-priming pump

Abstract

The application relates to the field of household appliance pumps, in particular to a small self-priming pump which comprises a pump shell assembly provided with a pump cavity; a flow channel separation assembly arranged in the pump cavity and matched with the pump shell assembly to form a water inlet cavity, an impeller pressurizing cavity and a gas-liquid separation cavity; an impeller; a connecting pipe, a backflow pipe and a circulation port which are connected with the cavities; and a water inlet pipe and a water outlet pipe. The backflow pipe and the connecting pipe constitute a jet structure, and the relative positions of the backflow pipe, the water inlet pipe and the connecting pipe are determined, so that the self-priming function is high in efficiency, the pump does not need to be arranged below a water tank or a water suction surface, the overall volume and the occupied space are reduced, the pump can be integrated in a household appliance, the volume of a water tank of the household appliance can be reduced, the water tank can be even removed, and the whole machine design is more flexible.

Description

Technical Field

[0001] This application relates to the field of pumps for household appliances, and more particularly to a small self-priming pump. Background Technology

[0002] Most existing household appliances use centrifugal pumps for water intake and drainage. These pumps lack self-priming capabilities and require the pump to be placed in a water tank or below the water surface, which greatly limits the pump's installation location. The water tanks also have a certain volume, taking up a significant portion of the appliance's space and resulting in larger household appliances. A search revealed Chinese patent 202210642966.X, which discloses a self-priming centrifugal pump. The pump body includes a motor chamber and a working chamber. A drive motor is located within the motor chamber. The pump body has an outlet at the top and an inlet on the side. A centrifugal impeller is located within the working chamber at the output end of the drive motor. The impeller has an inner inlet at its center and an outer outlet at its outer side. The pump body is characterized by a flow guide shroud enclosing the impeller within the working chamber. A flow guide port connecting the outlet to the working chamber is located on the side of the flow guide shroud. A flow guide pipe is provided on the flow guide shroud, with an inlet connected to the inlet, a return port connected to the working chamber, and an outlet connected to the inner inlet. A check valve is provided on the inlet, and an ejector with a return valve is provided on the return port. This patent has a complex structure, requiring additional check valves, ejectors, and return valves within the pump body, resulting in a large overall size that is unsuitable for household appliances. Utility Model Content

[0003] To address the shortcomings of existing technologies, this application provides a small self-priming pump.

[0004] To achieve the above objectives, the technical solution of this application is as follows: A small self-priming pump includes: a pump casing assembly with a pump chamber; a flow channel partition assembly disposed within the pump chamber and cooperating with the pump casing assembly to form an inlet chamber, an impeller pressurization chamber, and a gas-liquid separation chamber; an impeller disposed within the impeller pressurization chamber; a connecting pipe connecting the inlet chamber and the impeller pressurization chamber, with its outlet end located at the center inlet of the impeller; a return pipe connecting the gas-liquid separation chamber and the inlet chamber, with the bottom of the inlet chamber lower than the inlet end of the return pipe; the return pipe and the connecting pipe forming a jet structure; a circulation port connecting the outlet area of ​​the impeller pressurization chamber and the gas-liquid separation chamber and located around the circumference of the impeller pressurization chamber; an inlet pipe communicating with the inlet chamber, its height being higher than the height of the connecting pipe and higher than the height of the return pipe; and an outlet pipe communicating with the upper end of the gas-liquid separation chamber.

[0005] Furthermore, the flow channel separation assembly includes a first flow channel component and a second flow channel component. The first flow channel component includes a pressure boosting cover, a connecting pipe, and a flow channel cover connected in sequence. The pressure boosting cover cooperates with the inner wall of the pump housing assembly to form an impeller pressure boosting chamber. The flow channel cover is connected to the second flow channel component to form a water inlet chamber. The return pipe is disposed on the second flow channel component, and the circulation port is disposed on the pressure boosting cover. The second flow channel component is provided with a water inlet interface connected to the water inlet pipe.

[0006] Furthermore, the pump housing assembly includes a pump housing and a pump cover. The pump housing has a base plate and a circumferential sidewall. The pump cover is connected to the end of the circumferential sidewall away from the base plate, and a pump cavity is formed between the two. The pressure boosting cover abuts against the pump cover to form an impeller pressure boosting cavity between the two.

[0007] Furthermore, the outer circumferential shape of the pressure booster cover is adapted to the concave cavity of the pump housing, and the two are interlocked; the inner wall of the circumferential side wall is provided with a number of axially arranged positioning ribs, and the outer circumference of the pressure booster cover is provided with positioning grooves that cooperate with the positioning ribs.

[0008] Furthermore, the inlet pipe is connected to the base plate, and the outlet pipe is connected to the circumferential side wall; the second flow channel component is abutted and limited between the first flow channel component and the pump casing base plate, and a mating groove is formed inside the end of the inlet pipe connected to the base plate, and the second flow channel component is provided with an inlet pipe that is inserted and mated with the mating groove.

[0009] Furthermore, the second flow channel component is secured to the flow channel cover via a snap-fit ​​connection.

[0010] Furthermore, a motor is provided, which is connected to the outside of the pump cover, and the pump cover has a through hole through which the output shaft of the motor passes.

[0011] Furthermore, the pump cover has a sealing groove in the through hole, and the sealing groove has a sealing element that seals with the motor output shaft. The motor output shaft is directly driven with the impeller.

[0012] Furthermore, the return pipe is integrally formed with the second flow channel component, and its central axis is arranged along the impeller central axis. The inner wall of the return pipe has a funnel-shaped structure with the inlet end larger than the outlet end. The connecting pipe has an extension pipe extending into the water inlet chamber, and its central axis is arranged along the impeller central axis. The inner wall of the extension pipe has a funnel-shaped structure with the inlet end larger than the outlet end. A certain gap is provided between the outlet end of the return pipe and the inlet end of the extension pipe.

[0013] Furthermore, the circulation port includes a first circulation port located on the circumference of the impeller pressurization chamber near the outlet pipe and a second circulation port located on the circumference of the impeller pressurization chamber away from the outlet pipe, wherein the first circulation port is larger than the first circulation port.

[0014] The beneficial effects of this application are as follows: By setting up a jet structure composed of a return pipe and a connecting pipe, and considering the relative positions of the return pipe, inlet pipe, and connecting pipe, a highly efficient self-priming function is achieved. This eliminates the need to place the pump below a water tank or the water surface, thus reducing the overall size and space occupied, facilitating integration into household appliances, reducing the size of the appliance's water tank, or even eliminating the water tank altogether, making the overall design more flexible. Simultaneously, this structure simplifies the complex components of traditional self-priming pumps (such as check valves and ejectors), reducing manufacturing and maintenance costs, improving suction efficiency, reducing energy loss, and ensuring the stability of the gas-liquid separation process. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0016] Figure 1 This is a schematic diagram of the structure of a small self-priming pump provided in an embodiment of this application; Figure 2 An exploded view of a small self-priming pump provided in an embodiment of this application; Figure 3 A cross-sectional view of a small self-priming pump provided in an embodiment of this application; Figure 4 This is a schematic diagram of the fluid flow direction of a small self-priming pump provided in an embodiment of this application; Figure 5 This is a schematic diagram of the initial liquid level of a small self-priming pump provided in an embodiment of this application; Figure 6 A schematic diagram illustrating the working principle of the impeller pressurization chamber of a small self-priming pump provided in this application embodiment; Figure 7 A schematic diagram of the pump casing of a small self-priming pump provided in an embodiment of this application; Figure 8 A schematic diagram of the structure of the first flow channel component and the second flow channel component in the small self-priming pump provided in the embodiment of this application; Figure 9 A cross-sectional view of the first flow channel component in a small self-priming pump provided in an embodiment of this application; Figure 10 This is a schematic diagram of the structure of the second flow channel component in the small self-priming pump provided in the embodiment of this application.

[0017] In the diagram, 100 is the pump casing, 110 is the inlet pipe, 111 is the mating groove, 120 is the outlet pipe, 130 is the positioning rib, 200 is the pump cover, 300 is the motor, 310 is the motor output shaft, 320 is the seal, 400 is the impeller, 500 is the first flow channel component, 510 is the flow channel cover, 511 is the positioning slot, 520 is the pressure boosting cover, 521 is the first circulation port, 522 is the second circulation port, 523 is the positioning groove, 530 is the connecting pipe, 531 is the extension pipe, 532 is the second bell mouth, 600 is the second flow channel component, 610 is the inlet pipe, 620 is the return pipe, 621 is the first bell mouth, 630 is the positioning buckle, A is the inlet chamber, B is the impeller pressure boosting chamber, and C is the gas-liquid separation chamber. Detailed Implementation

[0018] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0020] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0021] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0023] In this application, "and / or" is merely a way of describing the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0024] It should be noted that in this application, the words "in some embodiments," "exemplarily," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "in some embodiments," "exemplarily," or "for example" should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of words such as "in some embodiments," "exemplarily," and "for example" is intended to present related concepts in a specific manner, meaning that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of this application. The appearance of the above words in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0025] To address the problems in related technologies, embodiments of this application provide a small self-priming pump, such as... Figures 1 to 3 As shown, the system includes a pump casing assembly with a pump chamber; a flow channel partition assembly disposed within the pump chamber and cooperating with the pump casing assembly to form an inlet chamber A, an impeller pressurization chamber B, and a gas-liquid separation chamber C; an impeller 400 disposed within the impeller pressurization chamber B; a connecting pipe 530 connecting the inlet chamber A and the impeller pressurization chamber B, with its outlet end located at the center inlet of the impeller 400; a return pipe 620 connecting the gas-liquid separation chamber C and the inlet chamber A, with the bottom of the inlet chamber A lower than the inlet end of the return pipe 620; the return pipe 620 and the connecting pipe 530 forming a jet structure; a circulation port connecting the outlet area of ​​the impeller pressurization chamber B and the gas-liquid separation chamber C and located around the impeller pressurization chamber B; an inlet pipe 110 connected to the inlet chamber A, with its height higher than the height of the connecting pipe 530 and higher than the height of the return pipe 620; and an outlet pipe 120 connected to the upper end of the gas-liquid separation chamber C.

[0026] In specific structures, such as Figure 4As shown, the flow channel partitioning assembly divides the pump chamber into three functional areas: inlet chamber A, impeller pressurization chamber B, and gas-liquid separation chamber C. Inlet chamber A temporarily stores the liquid to be drawn in. Impeller pressurization chamber B houses the impeller 400 for kinetic energy transfer, achieving fluid pressurization and pumping. It also creates a negative pressure vacuum within inlet chamber A for self-priming. Gas-liquid separation chamber C is used for gas-liquid separation. Connecting pipe 530 guides the liquid from inlet chamber A to the center of impeller 400, while return pipe 620 returns a portion of the liquid from gas-liquid separation chamber C to inlet chamber A. Together, they form a jet structure, enhancing the pumping efficiency during the self-priming start-up phase. A circulation port is located around the impeller pressurization chamber B, used to guide the pressurized fluid into gas-liquid separation chamber C for gas-liquid separation and for output through outlet pipe 120. Inlet pipe 110 is located at the bottom of pump casing 100, with its inlet height higher than connecting pipe 530 and return pipe 620. The water outlet pipe 120 is connected to the upper part of the gas-liquid separation chamber C and is used to discharge the separated gas and the liquid after the liquid level in the gas-liquid separation chamber C reaches the highest point.

[0027] When the small self-priming pump provided in this application embodiment is working, in the initial state, the pump chamber stores liquid at a certain liquid level, such as... Figure 5 As shown, the initial minimum liquid level height 'a' is higher than the positions of the return pipe 620, connecting pipe 530, and the lowest point of the impeller inlet, while the initial maximum liquid level height 'b' is lower than the position of the inlet pipe 110. This means that in the initial state, the inlet chamber A, impeller pressurization chamber B, and gas-liquid separation chamber C all store a certain amount of water and are connected through the return pipe 620, connecting pipe 530, and impeller inlet. After the pump is turned on, the impeller 400 is driven. Under the action of centrifugal force, the impeller 400 performs work on the water, such as... Figure 6 As shown, water is distributed within the circumference of the impeller pressurization chamber B, forming a water ring W. A vacuum V is created inside the impeller, initially drawing water from the inlet chamber into the impeller pressurization chamber B. The water around the impeller pressurization chamber B is discharged into the gas-liquid separation chamber C through a circulation port located at the circumference of the impeller pressurization chamber B. Since the gas density is less than that of water, it flows upwards to the outlet pipe 120, continuing to circulate within the gas-liquid separation chamber C. The pressurized water in the gas-liquid separation chamber C is accelerated and ejected into the impeller inlet region through a jet structure formed by the return pipe 620 and the connecting pipe 530. Due to the increased liquid velocity, the pressure in this region decreases, creating a vacuum, which accelerates the entry of air or water from the inlet chamber A into this region. Under the action of the impeller, the velocity at the inlet of impeller booster chamber B is further accelerated, and the pressure at the inlet of impeller booster chamber B is further reduced. At this time, air in the pump chamber and water inlet chamber is accelerated and drawn in. Then, the centrifugal force of the impeller accelerates the gas-liquid mixture and discharges it back into the gas-liquid separation chamber C. The air is discharged through the outlet. This process is repeated to achieve rapid self-priming. The entire process requires no additional valves or complex control mechanisms, has a compact structure, and is suitable for space-constrained scenarios such as household appliances.

[0028] This application's embodiments are applicable to household appliances, particularly cleaning and sewage disposal appliances. Considering that the fluid transported in these appliances may contain particulate impurities, when this application's embodiments are applied to self-priming sewage pumps, the internal flow channels must be designed according to the maximum impurity diameter to avoid clogging. Specifically, the impeller is designed based on the passing impurity particles, with a minimum flow diameter equal to the maximum diameter of the particulate matter, preventing clogging.

[0029] Alternatively, in some embodiments, such as Figure 2 , Figure 3 as well as Figure 8 As shown, the flow channel partition assembly includes a first flow channel component 500 and a second flow channel component 600, as... Figure 9 As shown, the first flow channel component 500 includes a pressure boosting cover 520, a connecting pipe 530, and a flow channel cover 510 connected in sequence. The pressure boosting cover 520 cooperates with the inner wall of the pump casing assembly to form an impeller pressure boosting chamber B. The flow channel cover 510 is connected to the second flow channel component 600 to form a water inlet chamber A. A return pipe 620 is disposed on the second flow channel component 600, and a circulation port is disposed on the pressure boosting cover 520. The second flow channel component 600 is provided with a water inlet interface connected to the water inlet pipe 110. This structure achieves precise division of each functional cavity and flow channel optimization through a split flow channel component, which facilitates manufacturing and assembly.

[0030] Alternatively, in some embodiments, such as Figure 2 , Figure 3 As shown, the pump housing assembly includes a pump housing 100 and a pump cover 200, as... Figure 7 As shown, the pump casing 100 has a base plate and circumferential sidewalls. The pump cover 200 is connected to the end of the circumferential sidewalls away from the base plate, forming a pump cavity between the two. The booster cover 520 abuts against the pump cover 200, forming an impeller booster chamber B between them. This structure, through the separate design of the pump casing 100 and the pump cover 200, facilitates the installation and maintenance of internal components. Specifically, the pump casing 100 and the pump cover 200 are fastened together with bolts, and a sealing ring is provided between them to ensure a reliable seal at the connection point.

[0031] Optionally, in some embodiments, the outer periphery of the pressure booster cover 520 is adapted to the cavity of the pump housing 100, and the two are interlocked; the inner wall of the circumferential sidewall is provided with a plurality of axially arranged positioning ribs 130, and the outer periphery of the pressure booster cover 520 is provided with positioning grooves 523 that mate with the positioning ribs 130. This interlocking and positioning structure ensures the accurate fixation of the first flow channel component 500 in the pump cavity, prevents displacement or vibration during operation, and facilitates assembly.

[0032] Optionally, in some embodiments, the inlet pipe 110 is connected to the base plate, and the outlet pipe 120 is connected to the circumferential side wall. The layout of the inlet pipe 110 and the outlet pipe 120 optimizes the pipe connection and reduces bends and pressure loss. The second flow channel component 600 is abutted and fixed between the first flow channel component 500 and the base plate of the pump housing 100. The end of the inlet pipe 110 connected to the base plate has a mating groove 111 inside. The second flow channel component 600 is provided with an inlet pipe 610 that is inserted and mated with the mating groove 111. This structure achieves a stable connection between the second flow channel component 600 and the inlet pipe 110 through insertion and abutment, ensuring that the inlet chamber A and the gas-liquid separation chamber are connected only through the return pipe 620. Furthermore, the fixing method of the second flow channel component 600 does not require additional fasteners, reducing cost and assembly complexity.

[0033] Optionally, in some embodiments, the second flow channel component 600 is snap-fitted to the flow channel cover 510. This ensures a stable connection between the first flow channel component 500 and the second flow channel component 600, as well as the stability of the water inlet chamber A.

[0034] Optionally, in some embodiments, a motor 300 is provided, which is connected to the outside of the pump cover 200, and the pump cover 200 is provided with a through hole through which the motor output shaft 310 passes.

[0035] Optionally, in some embodiments, a sealing groove is provided in the through hole of the pump cover 200, and a sealing element 320 is provided in the sealing groove to seal with the motor output shaft 310. The motor output shaft 310 and the impeller 400 are directly driven together. The sealing element 320 prevents liquid leakage to the motor 300 side, ensuring the reliability of dynamic sealing and preventing water vapor from corroding the motor 300. The direct drive reduces the number of components such as couplings, simplifying the connection structure. Specifically, the sealing element 320 adopts a double O-ring structure.

[0036] Optionally, in some embodiments, the return pipe 620 is integrally formed with the second flow channel component 600, and its central axis is arranged along the central axis of the impeller 400. The inner wall of the return pipe 620 has a funnel-shaped structure with the inlet end larger than the outlet end. The connecting pipe 530 has an extension pipe 531 extending into the water inlet chamber A, and its central axis is arranged along the central axis of the impeller 400. The inner wall of the extension pipe 531 has a funnel-shaped structure with the inlet end larger than the outlet end. A certain gap is provided between the outlet end of the return pipe 620 and the inlet end of the extension pipe 531. The integral forming reduces the risk of leakage and assembly steps, the funnel-shaped structure improves the liquid flow rate and spray efficiency, and the gap design allows the liquid to form a negative pressure during the spraying process, enhancing the self-priming capability.

[0037] Optionally, in some embodiments, the circulation port includes a first circulation port 521 located on the circumference of the impeller pressurization chamber B near the outlet pipe 120 and a second circulation port 522 located on the circumference of the impeller pressurization chamber B away from the outlet pipe 120, wherein the first circulation port 521 is larger than the second circulation port 522. The different sizes of circulation ports enable staged gas-liquid separation, improving separation efficiency. The larger first circulation port 521 facilitates the entry of a large amount of liquid into the gas-liquid separation chamber C for preliminary separation, while the smaller second circulation port 522 is used for fine separation and stabilizing the flow field.

[0038] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A small self-priming pump, characterized in that, include: Pump housing assembly, which includes a pump chamber; The flow channel partition assembly is located inside the pump cavity and cooperates with the pump casing assembly to form an inlet chamber, an impeller pressurization chamber, and a gas-liquid separation chamber. An impeller is disposed within the impeller pressurization chamber; The connecting pipe connects the water inlet chamber and the impeller pressurization chamber, and its outlet end is located at the center inlet of the impeller. A return pipe connects the gas-liquid separation chamber and the water inlet chamber, and the bottom of the water inlet chamber is set lower than the inlet end of the return pipe; The return pipe and connecting pipe constitute the jet structure; The circulation port connects the outlet area of ​​the impeller boosting chamber and the gas-liquid separation chamber and is located around the impeller boosting chamber. The inlet pipe is connected to the inlet chamber and its height is higher than the height of the connecting pipe and higher than the height of the return pipe. The water outlet pipe is connected to the upper end of the gas-liquid separation chamber.

2. The small self-priming pump according to claim 1, characterized in that, The flow channel separation assembly includes a first flow channel component and a second flow channel component. The first flow channel component includes a pressure boosting cover, a connecting pipe, and a flow channel cover connected in sequence. The pressure boosting cover cooperates with the inner wall of the pump housing assembly to form an impeller pressure boosting chamber. The flow channel cover is connected to the second flow channel component to form a water inlet chamber. The return pipe is disposed on the second flow channel component. The circulation port is disposed on the pressure boosting cover. The second flow channel component is provided with a water inlet interface connected to the water inlet pipe.

3. The small self-priming pump according to claim 2, characterized in that, The pump housing assembly includes a pump housing and a pump cover. The pump housing has a base plate and a circumferential sidewall. The pump cover is connected to the end of the circumferential sidewall away from the base plate, and a pump cavity is formed between the two. The pressure boosting cover abuts against the pump cover to form an impeller pressure boosting cavity between the two.

4. The small self-priming pump according to claim 3, characterized in that, The outer circumference of the pressure booster cover is adapted to the concave cavity of the pump casing, and the two are interlocked; the inner wall of the circumferential side wall is provided with a number of positioning ribs arranged along the axial direction, and the outer circumference of the pressure booster cover is provided with positioning grooves that cooperate with the positioning ribs.

5. The small self-priming pump according to claim 3, characterized in that, The inlet pipe is connected to the base plate, and the outlet pipe is connected to the circumferential side wall; the second flow channel component is abutted and limited between the first flow channel component and the pump casing base plate, and a mating groove is formed inside the end of the inlet pipe connected to the base plate, and the second flow channel component is provided with an inlet pipe that is inserted and mated with the mating groove.

6. The small self-priming pump according to claim 5, characterized in that, The second flow channel component is fixed to the flow channel cover by a snap-fit ​​connection.

7. The small self-priming pump according to claim 3, characterized in that, The pump is equipped with a motor, which is connected to the outside of the pump cover, and the pump cover has a through hole through which the output shaft of the motor passes.

8. The small self-priming pump according to claim 7, characterized in that, The pump cover has a sealing groove in the through hole, and the sealing groove has a sealing element that seals with the motor output shaft. The motor output shaft is directly driven with the impeller.

9. The small self-priming pump according to any one of claims 2-8, characterized in that, The return pipe is integrally formed with the second flow channel component, and its central axis is set along the direction of the impeller central axis. The inner wall of the return pipe has a funnel-shaped structure with the inlet end larger than the outlet end. The connecting pipe has an extension pipe that extends into the water inlet chamber, and its central axis is set along the direction of the impeller central axis. The inner wall of the extension pipe has a funnel-shaped structure with the inlet end larger than the outlet end. A certain gap is provided between the outlet end of the return pipe and the inlet end of the extension pipe.

10. The small self-priming pump according to any one of claims 1-8, characterized in that, The circulation port includes a first circulation port located on the circumference of the impeller boosting chamber near the outlet pipe and a second circulation port located on the circumference of the impeller boosting chamber away from the outlet pipe, wherein the first circulation port is larger than the first circulation port.

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