Self-exhaust type inverted drainage pump
By setting up an exhaust passage in the inverted drain pump and using the inlet pressure to drive air discharge, the problem of insufficient self-priming function of the inverted drain pump in the prior art is solved, and the combination of self-exhaust and self-priming functions is realized, simplifying user operation.
Patent Information
- Application Number
- CN202422178941.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-05
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2034-09-05
AI Technical Summary
The existing centrifugal drain pumps lack self-priming function when inverted, resulting in insufficient vacuum in the pump chamber, difficult to absorb water, and it is difficult for users to solve this problem by sucking water or pumping air.
A self-exhaust inverted drainage pump is designed. By setting an exhaust passage between the rotor chamber of the pump casing and the outlet pipe of the pump cover, the pressure when the water inlet pipe is used to drive the air to discharge along the exhaust passage, and realize the self-exhaust function.
This design realizes the self-exhaust function, which can be used normally without the need for user to simmer or pump air, simplifying the operation process.
Smart Images
Figure CN223018942U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of water pumps and their components, and specifically relates to a self-exhausting inverted drainage pump. Background Art
[0002] The electronic water pump has a high output efficiency and can achieve precise flow control. Therefore, the electronic water pump is widely used in household appliances, automobiles, and industrial equipment. For example, household appliances such as water heating mattresses, air conditioners, and humidifying appliances are increasingly equipped with electronic water pumps in order to achieve the function of precise quantitative liquid circulation / discharge.
[0003] The drainage pump is an important application of the electronic water pump, which can discharge the liquid in structures such as water tanks and sinks to other places.
[0004] The centrifugal drainage pump in the prior art lacks a self-priming function. When the centrifugal drainage pump is inverted, air will remain in its outlet pipe and pump cavity. If the outlet pipe and pump cavity are not filled with water, or the air in the outlet pipe and pump cavity is not pumped out, the vacuum degree in the pump cavity will be insufficient, resulting in difficulty for the centrifugal drainage pump to absorb water.
[0005] The common solution to the above problems is to continue filling water or pump out the air in the inlet pipe. However, the above operations require certain professional training or special equipment, which is difficult for some users to achieve.
[0006] In summary, how to provide a self-exhausting function for the inverted drainage pump has become one of the problems to be solved urgently. Content of the Utility Model
[0007] The purpose of the utility model is to provide a self-exhausting inverted drainage pump, which has a self-exhausting function and can thus achieve a self-priming function.
[0008] To achieve the above purpose, the utility model provides the following technical solution: A self-exhausting inverted drainage pump, which at least includes a pump cover, a rotor-impeller assembly, and a pump housing; an impeller chamber is formed inside the pump cover, and an inlet pipe and an outlet pipe communicating with both the inside and outside of the impeller chamber are respectively formed on the pump cover; a rotor chamber is formed in the pump housing, and the pump cover is covered on the pump housing so that the impeller chamber of the pump cover communicates with the rotor chamber of the pump housing; the rotor-impeller assembly at least includes a main impeller that can rotate in the impeller chamber of the pump cover; an exhaust passage is provided between the rotor chamber of the pump housing and the outlet pipe of the pump cover; when water enters through the inlet pipe of the pump cover, the air in the rotor chamber of the pump housing is driven by pressure, reaches the outlet pipe of the pump cover along the exhaust passage, and is discharged outside the outlet pipe.
[0009] In the above technical solution, the self-exhausting inverted drainage pump of the present utility model further includes an independent exhaust pipe; an exhaust inlet branch pipe is formed at the rotor chamber of the pump housing, and an intermediate exhaust pipe is also formed at the pump housing; an exhaust outlet branch pipe is formed at the water outlet pipe of the pump cover; the exhaust inlet branch pipe of the pump housing, the independent exhaust pipe, the intermediate exhaust pipe of the pump housing, and the exhaust outlet branch pipe of the pump cover are sequentially communicated to form the exhaust passage.
[0010] In the above technical solution, the independent exhaust pipe is a flexible pipe; both ends of the independent exhaust pipe are respectively sleeved on the ends of the exhaust inlet branch pipe and the intermediate exhaust pipe of the pump housing, and are sealed by its own flexibility.
[0011] In the above technical solution, the rotor-impeller assembly includes a rotating shaft, a rotor bracket, a magnetic ring, the main impeller, and an inlet impeller; the rotating shaft is supported by the pump housing and the pump cover, and penetrates through the rotor chamber of the pump housing and the impeller chamber of the pump cover until it reaches the water inlet pipe of the pump cover; the rotor bracket is sleeved on the rotating shaft and rotates with the rotating shaft, the magnetic ring is sleeved on the rotor bracket and is coaxially arranged with the rotor bracket, the main impeller is fixed at one end of the rotor bracket and is coaxially arranged with the rotor bracket; the inlet impeller is sleeved on a section of the rotating shaft located in the water inlet pipe and rotates with the rotating shaft.
[0012] In the above technical solution, a rotating shaft seat is formed in the rotor chamber of the pump housing, a rotating shaft bracket is formed inside the water inlet pipe of the pump cover, and the rotating shaft seat of the pump housing is aligned with the rotating shaft bracket of the pump cover; at least a part of the rotating shaft of the rotor-impeller assembly is supported by a first bearing at the rotating shaft seat of the pump housing, and at least another part of it is supported by a second bearing at the rotating shaft bracket of the pump cover.
[0013] In the above technical solution, a water inlet grille is formed on the side of the water inlet pipe of the pump cover, and the water inlet grille of the pump cover is aligned with the inlet impeller of the rotor-impeller assembly in the radial direction.
[0014] In the above technical solution, the water inlet pipe of the pump cover includes an outer layer water inlet pipe and an inner layer water inlet pipe coaxially arranged from outside to inside; the water inlet grille of the pump cover includes an outer layer water inlet grille arranged at the outer layer water inlet pipe and an inner layer water inlet grille arranged at the inner layer water inlet pipe.
[0015] In the above technical solution, the blades of the inlet impeller are one of fan-shaped blades, spiral blades, and paddle-shaped blades.
[0016] In the above technical solution, the self-exhausting inverted drainage pump of the present utility model further includes a stator assembly, a drive circuit board, and a rear end cover; the stator assembly is disposed within the pump housing and outside the rotor chamber of the pump housing, and the stator assembly and the magnetic ring of the rotor-impeller assembly are radially aligned with each other; the drive circuit board is disposed within the pump housing and electrically connected to the stator assembly; the rear end cover is fixed to the other end of the pump housing relative to the pump cover to shield the stator assembly and the drive circuit board.
[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows: In the self-exhausting inverted drainage pump of the present utility model, an exhaust passage is provided between the rotor chamber of the pump housing and the water outlet pipe of the pump cover. When water enters through the water inlet pipe of the pump cover, the air in the rotor chamber of the pump housing is driven by pressure, travels along the exhaust passage to the water outlet pipe of the pump cover, and is discharged outside the water outlet pipe; the self-exhausting inverted drainage pump of the present utility model has a self-exhaust function, and thus can achieve a self-priming function. When in use, it can be used normally without filling with water or exhausting the air in the rotor chamber. Description of the Drawings
[0018] Figure 1 is a perspective view of the present utility model.
[0019] Figure 2 is an exploded view of the present utility model.
[0020] Figure 3 is a sectional view of the present utility model.
[0021] The reference numerals are: 1, pump cover; 11, water inlet pipe; 111, outer water inlet pipe; 1111, outer water inlet grille; 112, inner water inlet pipe; 1121, inner water inlet grille; 12, water outlet pipe; 121, exhaust outlet branch pipe; 13, rotating shaft bracket; 14, second bearing; 15, impeller chamber; 2, rotor-impeller assembly; 21, rotating shaft; 22, rotor bracket; 221, impeller fixing part; 23, main impeller; 24, magnetic ring; 25, water inlet impeller; 3, pump housing; 31, rotor chamber; 311, exhaust inlet branch pipe; 32, first bearing; 33, intermediate exhaust pipe; 4, stator assembly; 5, drive circuit board; 6, rear end cover; 7, independent exhaust pipe; 10, exhaust passage. Detailed Embodiments
[0022] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0023] This embodiment provides a self-exhausting inverted drainage pump, which has a self-exhaust function and can thus achieve a self-priming function.
[0024] Taking a centrifugal electronic water pump as an example, this embodiment specifically illustrates the technical solution of the present utility model.
[0025] Please refer to Figures 1-3 , the self-exhausting inverted drainage pump of this embodiment at least includes a pump cover 1, a rotor-impeller assembly 2, and a pump housing 3.
[0026] Among them, the pump cover 1 is an integrally formed engineering plastic or metal cover-shaped member, and the pump housing 3 is an integrally formed engineering plastic or metal semi-shell member, which provides a structural support foundation for the self-exhausting inverted drainage pump of this embodiment.
[0027] An impeller chamber 15 is formed inside the pump cover 1. Moreover, a water inlet pipe 11 and a water outlet pipe 12 that communicate with the inner and outer sides of the impeller chamber 15 are respectively formed on the pump cover 1. Specifically, the impeller chamber 15 is a cavity inside the pump cover 1, and both the water inlet pipe 11 and the water outlet pipe 12 are rigid short pipes integrally formed at the pump cover 1.
[0028] A rotor chamber 31 is formed in the pump housing 3, and the rotor chamber 31 is a cavity structure integrally formed with the pump housing 3; the pump cover 1 is covered on the pump housing 3, so that the impeller chamber 15 of the pump cover 1 communicates with the rotor chamber 31 of the pump housing 3; it can be understood that the pump cover 1 and the pump housing 3 can be fixed together by means of screws or buckles, etc., and a sealing ring is provided at the connection between the two to achieve sealing.
[0029] The rotor-impeller assembly 2 at least includes a main impeller 23 that can rotate in the impeller chamber 15 of the pump cover 1 to drive the liquid to flow.
[0030] In order to achieve the self-exhaust function, an exhaust passage 10 is provided between the rotor chamber 31 of the pump housing 3 and the water outlet pipe 12 of the pump cover 1; when water enters through the water inlet pipe 11 of the pump cover 1, the air in the rotor chamber 31 of the pump housing 3 is driven by the pressure, reaches the water outlet pipe 12 of the pump cover 1 along the exhaust passage 10, and is discharged outside the water outlet pipe 12.
[0031] Further specifically, the self-exhausting inverted drainage pump of this embodiment further includes an independent exhaust pipe 7, and the independent exhaust pipe 7 is a flexible short pipe made of silica gel, rubber or flexible plastic; an exhaust inlet branch pipe 311 is formed at the rotor chamber 31 of the pump housing 3, that is, the exhaust inlet branch pipe 311 is a rigid short pipe structure integrally formed at the bottom of the rotor chamber 31 and penetrating through the rotor chamber 31; and an intermediate exhaust pipe 33 is further formed at the pump housing 3, that is, the intermediate exhaust pipe 33 is a rigid short pipe structure integrally formed at the pump housing 3; an exhaust outlet branch pipe 121 is formed at the water outlet pipe 12 of the pump cover 1, that is, the exhaust outlet branch pipe 121 is a rigid branch pipe structure integrally formed at the water outlet pipe 12 and communicating the inner and outer sides of the water outlet pipe 12; the exhaust inlet branch pipe 311 of the pump housing 3, the independent exhaust pipe 7, the intermediate exhaust pipe 33 of the pump housing 3 and the exhaust outlet branch pipe 121 of the pump cover 1 are sequentially communicated to form an exhaust passage 10; wherein, both ends of the independent exhaust pipe 7 are respectively sleeved on the ends of the exhaust inlet branch pipe 311 and the intermediate exhaust pipe 33 of the pump housing 3, and are sealed by its own flexibility; wherein, the free end of the exhaust outlet branch pipe 121 of the pump cover 1 directly penetrates into the intermediate exhaust pipe 33 of the pump housing 3, and a sealing ring is arranged between the two to achieve sealing.
[0032] Specifically, the rotor-impeller assembly 2 includes a rotating shaft 21, a rotor bracket 22, a magnetic ring 24, a main impeller 23, and a water inlet impeller 25. Among them, the rotating shaft 21 is a cylindrical metal shaft, the rotor bracket 22 is a bracket made of engineering plastic, which provides a structural support foundation for the rotor-impeller assembly 2. The magnetic ring 24 is an annular body member with permanent magnetism. The main impeller 23 is a wheel-shaped member made of engineering plastic with several blades, and the water inlet impeller 25 is a bushing member made of engineering plastic with several blades. The rotor bracket 22 is sleeved on the rotating shaft 21 and rotates with the rotating shaft 21. The magnetic ring 24 is sleeved on the rotor bracket 22 and is coaxially arranged with the rotor bracket 22. The main impeller 23 is fixed at one end of the rotor bracket 22 and is coaxially arranged with the rotor bracket 22. In fact, by placing the rotating shaft 21 and the magnetic ring 24 into the molding die of the rotor bracket 22 and using in-mold injection molding to form the rotor bracket 22, the rotating shaft 21, the magnetic ring 24, and the rotor bracket 22 can be formed into one body. The rotating shaft 21 and the magnetic ring 24 are respectively matched with the rotor bracket 22 through a groove-rib structure (or a key structure) to achieve anti-rotation (that is, the rotating shaft 21, the magnetic ring 24, and the rotor bracket 22 can rotate synchronously). Then, the main impeller 23 is fixed on the combined body of the rotor bracket 22 by ultrasonic welding (specifically welded to the impeller fixing part 221 at the end of the rotor bracket 22), and the manufacturing of the rotor-impeller assembly 2 is completed. The rotating shaft 21 is supported by the pump casing 3 and the pump cover 1 and penetrates through the rotor chamber 31 of the pump casing 3 and the impeller chamber 15 of the pump cover 1 until it reaches the water inlet pipe 11 of the pump cover 1. Specifically, a rotating shaft seat is formed in the rotor chamber 31 of the pump casing 3 (the rotating shaft seat is integrally formed at the bottom of the rotor chamber 31), and a rotating shaft bracket 13 is formed inside the pump cover 1 on the inner side of the water inlet pipe 11 (the rotating shaft bracket 13 is integrally formed on the inner side of the pump cover 1). The rotating shaft seat of the pump casing 3 and the rotating shaft bracket 13 of the pump cover 1 are aligned with each other. At least a part of the rotating shaft 21 of the rotor-impeller assembly 2 is supported at the rotating shaft seat of the pump casing 3 through a first bearing 32 (such as a ceramic bearing or a graphite bearing, and embedded in the rotating shaft seat), and at least another part of it is supported at the rotating shaft bracket 13 of the pump cover 1 (such as a ceramic bearing or a graphite bearing, and embedded in the rotating shaft bracket 13) through a second bearing 14. The water inlet impeller 25 is sleeved on a section of the rotating shaft 21 located in the water inlet pipe 11 and rotates with the rotating shaft 21. In fact, the water inlet impeller 25 is in interference fit with the rotating shaft 21 and is matched with the rotating shaft 21 through a key structure to achieve anti-rotation (the water inlet impeller 25 and the rotating shaft 21 can rotate synchronously).
[0033] Specifically, the blades of the water inlet impeller 25 are one of fan-shaped blades, spiral blades, and paddle-shaped blades. In this embodiment, the blades of the water inlet impeller 25 are fan-shaped blades.
[0034] The self-exhausting inverted drainage pump of this embodiment further includes a stator assembly 4, a drive circuit board 5, and a rear end cover 6; the stator assembly 4 at least includes a stator bracket (also known as "stator core"), and an enameled wire coil wound around the stator bracket, which can generate a rotating magnetic field during operation to drive the rotation of the rotor-impeller assembly 2; the drive circuit board 5 is a printed circuit board (PCB), which is equipped with a main control, power electronic devices for driving the operation of the stator assembly 4, and necessary peripheral circuits for driving the operation of the stator assembly 4; the rear end cover 6 is an integrally formed cover-shaped member made of engineering plastic or metal material; the stator assembly 4 is arranged in the pump housing 3 and outside the rotor chamber 31 of the pump housing 3, and the magnetic ring 24 of the stator assembly 4 and the rotor-impeller assembly 2 are aligned with each other in the radial direction. In this embodiment, the stator assembly 4 is sleeved outside the rotor chamber 31 of the pump housing 3, and it can be fixed in the pump housing 3 by means of snap fastening or screw screwing; the drive circuit board 5 is arranged in the pump housing 3 and is electrically connected to the stator assembly 4. In fact, the drive circuit board 5 can be fixed in the pump housing 3 by means of snap fastening or screw screwing. In some possible embodiments, terminals are provided at the ends of the enameled wire coil of the stator assembly 4, and the terminals are welded to the drive circuit board 5 to achieve the electrical connection between the stator assembly 4 and the drive circuit board 5; the rear end cover 6 is fixed to the other end of the pump housing 3 relative to the pump cover 1 to shield the stator assembly 4 and the drive circuit board 5. It can be understood that the rear end cover 6 and the pump housing 3 can be fixed together by means of screws or snaps, and a sealing ring is provided at the joint between the two to achieve sealing.
[0035] Further, a water inlet grille is formed on the side of the water inlet pipe 11 of the pump cover 1, and the water inlet grille of the pump cover 1 is aligned with the water inlet impeller 25 of the rotor-impeller assembly 2 in the radial direction.
[0036] Further, the water inlet pipe 11 of the pump cover 1 includes an outer layer water inlet pipe 111 and an inner layer water inlet pipe 112 coaxially arranged from outside to inside. Both the outer layer water inlet pipe 111 and the inner layer water inlet pipe 112 are rigid short pipes integrally formed at the pump cover 1 and form a coaxial spaced nested structure; the water inlet grille of the pump cover 1 includes an outer layer water inlet grille 1111 provided at the outer layer water inlet pipe 111, and an inner layer water inlet grille 1121 provided at the inner layer water inlet pipe 112. In fact, the outer layer water inlet grille 1111 is a grille structure integrally formed at the outer layer water inlet pipe 111, and the inner layer water inlet grille 1121 is a grille structure integrally formed at the inner layer water inlet pipe 112.
[0037] Setting the water inlet pipe 11 of the pump cover 1 as a spaced nested structure of the outer layer water inlet pipe 111 and the inner layer water inlet pipe 112 can effectively isolate large particle impurities during water inlet and protect the water inlet impeller 25.
[0038] When the self-exhausting inverted drainage pump of this embodiment is in use, an external power source is connected to drive the circuit board 5. The drive circuit board 5 supplies power to the enameled wire coil of the stator assembly 4. After the enameled wire coil is powered on, an alternating magnetic field can be generated. After being guided by the stator bracket (stator core), a rotating magnetic field can be generated in the rotor chamber 31. This rotating magnetic field is located in the rotor chamber 31 in space. The rotor-impeller assembly 2 in the rotor chamber 31 has its magnetic ring 24 magnetically coupled with this rotating magnetic field, causing the entire rotor-impeller assembly 2 to start rotating. When the main impeller 23 in the impeller chamber 15 rotates, a directional pressure difference can be generated in the impeller chamber 15, thereby driving the liquid to be sucked into the impeller chamber 15 from the water inlet pipe 11 and discharged from the water outlet pipe 12, thus completing the function of the water pump.
[0039] Please refer to Figure 3 , in the above process, when the liquid is sucked into the impeller chamber 15, the air remaining in the rotor chamber 31 is driven by the pressure and reaches the water outlet pipe 12 of the pump cover 1 along the exhaust passage 10 (successively the exhaust inlet branch pipe 311 of the pump housing 3, the independent exhaust pipe 7, the intermediate exhaust pipe 33 of the pump housing 3, and the exhaust outlet branch pipe 121 of the pump cover 1), and is discharged outside the water outlet pipe 12. Without filling with water or evacuating the air in the rotor chamber 31, the self-exhausting inverted drainage pump of this embodiment can be used normally.
[0040] In the above process, the water inlet impeller 25 also rotates with the rotating shaft 21. The rotating water inlet impeller 25 can suck the liquid at the water inlet pipe 11 into the impeller chamber 15, and then form a stable water flow under the drive of the main impeller 23. Even if the liquid level is relatively shallow, as long as the liquid level can contact the water inlet impeller 25, it can operate normally without initial water supply. The side of the water inlet pipe 11 of the pump cover 1 is formed with a water inlet grille, which is conducive to the liquid entering the water inlet pipe 11 and contacting the water inlet impeller 25. Therefore, the water inlet grille and the water inlet impeller 25 have a cooperative effect.
[0041] For the self-exhausting inverted drainage pump of this embodiment, an exhaust passage 10 is provided between the rotor chamber 31 of the pump housing 3 and the water outlet pipe 12 of the pump cover 1. When water enters through the water inlet pipe 11 of the pump cover 1, the air in the rotor chamber 31 of the pump housing 3 is driven by the pressure and reaches the water outlet pipe 12 of the pump cover 1 along the exhaust passage 10, and is discharged outside the water outlet pipe 12. The self-exhausting inverted drainage pump of this embodiment has a self-exhaust function, and thus can realize a self-priming function. When in use, it can be used normally without filling with water or evacuating the air in the rotor chamber 31.
[0042] Although embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.
Claims
1. A self-exhausting inverted drainage pump, characterized in that: It includes at least a pump cover, a rotor-impeller assembly and a pump casing; An impeller chamber is formed on the inner side of the pump cover, and a water inlet pipe and a water outlet pipe are respectively formed on the pump cover to communicate with both sides of the impeller chamber inside and outside; A rotor chamber is formed in the pump housing, and the pump cover is covered on the pump housing so that the impeller chamber of the pump cover and the rotor chamber of the pump housing are communicated with each other; The rotor-impeller assembly includes at least a main impeller rotatable in an impeller chamber of the pump cover; An exhaust passage is provided between the rotor chamber of the pump housing and the water outlet pipe of the pump cover; When water is introduced through the water inlet pipe of the pump cover, the air in the rotor chamber of the pump housing is driven by pressure to reach the water outlet pipe of the pump cover along the exhaust passage and is discharged outside the water outlet pipe.
2. The self-exhaust inverted drainage pump according to claim 1, characterized in that: Also included is a separate exhaust; An exhaust inlet branch pipe is formed at the rotor chamber of the pump housing, and an intermediate exhaust pipe is also formed at the pump housing; An exhaust outlet branch pipe is formed at the water outlet pipe of the pump cover; The exhaust inlet branch pipe of the pump housing, the independent exhaust pipe, the intermediate exhaust pipe of the pump housing and the exhaust outlet branch pipe of the pump cover are connected in sequence to form the exhaust passage.
3. The self-exhaust inverted drainage pump according to claim 2, characterized in that: The independent exhaust pipe is a flexible pipe; The two ends of the independent exhaust pipe are respectively sleeved on the ends of the exhaust inlet branch pipe and the intermediate exhaust pipe of the pump housing, and are sealed by their own softness.
4. The self-exhaust inverted drainage pump according to any one of claims 1 to 3, characterized in that: The rotor-impeller assembly comprises a rotating shaft, a rotor bracket, a magnetic ring, the main impeller and a water inlet impeller; The rotating shaft is supported by the pump casing and the pump cover, and passes through the rotor chamber of the pump casing and the impeller chamber of the pump cover until reaching the water inlet pipe of the pump cover; The rotor support is sleeved on the rotating shaft and rotates with the rotating shaft, the magnetic ring is sleeved on the rotor support and is coaxially arranged with the rotor support, and the main impeller is fixed at one end of the rotor support and is coaxially arranged with the rotor support; The water inlet impeller is sleeved on a section of the rotating shaft located in the water inlet pipe and rotates along with the rotating shaft.
5. The self-exhaust inverted drainage pump according to claim 4, characterized in that: A rotating shaft seat is formed in the rotor chamber of the pump housing, and a rotating shaft bracket is formed on the inner side of the water inlet pipe of the pump cover, and the rotating shaft seat of the pump housing and the rotating shaft bracket of the pump cover are aligned with each other; At least a portion of the rotating shaft of the rotor-impeller assembly is supported at the rotating shaft seat of the pump housing through a first bearing, and at least another portion of the rotating shaft is supported at the rotating shaft support of the pump cover through a second bearing.
6. The self-exhaust inverted drainage pump according to claim 4 or 5, characterized in that: A water inlet grille is formed on the side of the water inlet pipe of the pump cover, and the water inlet grille of the pump cover and the water inlet impeller of the rotor-impeller assembly are aligned with each other in the radial direction.
7. The self-exhaust inverted drainage pump according to claim 6, characterized in that: The water inlet pipe of the pump cover comprises an outer water inlet pipe and an inner water inlet pipe coaxially arranged from outside to inside; The water inlet grille of the pump cover includes an outer water inlet grille arranged at the outer water inlet pipe, and an inner water inlet grille arranged at the inner water inlet pipe.
8. The self-exhaust inverted drainage pump according to claim 4, characterized in that: The blades of the water inlet impeller are one of fan-shaped blades, spiral blades and paddle-shaped blades.
9. The self-exhaust inverted drainage pump according to claim 4, characterized in that: Also includes a stator assembly, a drive circuit board and a rear end cover; The stator assembly is arranged in the pump housing and outside the rotor chamber of the pump housing, and the magnetic rings of the stator assembly and the rotor-impeller assembly are aligned with each other in the radial direction; The driving circuit board is disposed in the pump housing and is electrically connected to the stator assembly; The rear end cover is fixed to the other end of the pump housing relative to the pump cover to shield the stator assembly and the driving circuit board.