CN116480590A - Axial force self-balancing centrifugal pump - Google Patents

Abstract

The invention relates to the technical field of centrifugal pumps, in particular to an axial force self-balancing centrifugal pump which comprises a pump body and a motor, wherein the pump body comprises a fixed shell, a first impeller, a second impeller and a drainage pipeline, a containing cavity is formed in the fixed shell, a water inlet hole and a water outlet hole are formed in the fixed shell, the first impeller is coaxially and movably arranged in the containing cavity, the second impeller is in transmission connection with an output shaft of the motor, the second impeller can drive the first impeller to rotate, the drainage pipeline is fixedly arranged in the containing cavity, one end of the drainage pipeline is arranged at the water inlet hole, and the other end of the drainage pipeline is arranged between the second impeller and the motor and faces the second impeller. The invention ensures that the whole device can not generate friction loss due to axial force caused by water flow at any time in the use process, simultaneously ensures that partial water flow for diversion can be stably discharged from the water outlet hole, and prolongs the service life of the whole device.

Description

Axial force self-balancing centrifugal pump

Technical Field

The invention relates to the technical field of centrifugal pumps, in particular to an axial force self-balancing centrifugal pump.

Background

The axial force of the pump, especially the centrifugal pump, is generated when the impeller rotates. The root cause of this is that the front and rear cover plates of the centrifugal pump impeller are unbalanced by the fluid force. When the centrifugal pump operates, the impeller drives the liquid to rotate, and in the process, high-pressure liquid flowing out of the impeller can leak into clearance spaces formed by the front cover plate, the rear cover plate, the pump body and the pump cover of the impeller. However, the pressure areas of the front cover plate and the rear cover plate of the centrifugal pump impeller are unequal, the area of the rear cover plate in the impeller corresponding to the impeller suction inlet is low pressure, and the area corresponding to the outer part of the rear cover plate is high pressure. Because the front cover plate and the rear cover plate of the impeller are subjected to different pressures, and the pressure difference exists in the area of the rear cover plate in the impeller corresponding to the impeller suction inlet, the pressure difference formed between the front cover plate and the rear cover plate of the impeller cannot be self-balanced, and therefore an axial force pointing to the direction of the impeller suction inlet is generated. At present, a commonly adopted balancing method is to install a thrust ball bearing or an angular contact bearing on a pump shaft for balancing, the bearing is required to bear axial force and radial force, and further bear bidirectional alternating load, so that the bearing is easy to wear and discard, and the service life of the bearing is short.

Chinese patent CN217652952U discloses a self-balancing axial force's single-suction centrifugal pump, through introducing the high-pressure water of impeller water inlet side outer fringe to the back central part of impeller, and then make the water pressure of impeller water inlet side and back equal and realize the self-balancing of impeller, and then realize the axial force balance of pump shaft, effectively avoided the pump shaft bearing to bear the double load and the transitional wear that causes, this scheme is because the removal of rivers needs certain time in the use, from this time difference that leads to the impeller both sides to accept the time difference of water pressure, thereby the pump shaft bearing still receives axial force and consequently makes the pump shaft bearing receive wearing and tearing in this time difference, this kind of wearing and tearing cumulatively gets down many times and just can lead to the pump shaft bearing unable to continue to work, consequently, the life of whole device still can not accord with present long-time work requirement.

Disclosure of Invention

In order to solve the above problems, an axial force self-balancing centrifugal pump is provided, water flows enter a containing cavity through a drainage pipeline and are divided into two convection flows so as to offset axial force, and the first impeller and the second impeller cannot be extruded with other parts before the axial force between the two water flows offset each other through a gap between the first impeller and the second impeller.

In order to solve the problems in the prior art, the invention adopts the following technical scheme:

the utility model provides an axial force self-balancing centrifugal pump, including the pump body and the motor, the pump body includes the fixed shell, first impeller, second impeller and drainage pipeline, the holding chamber has been seted up to the inside of fixed shell, the holding chamber is wholly cylindrical, the output shaft of motor inserts to holding intracavity portion and with hold the coaxial setting of chamber, inlet opening and apopore have been seted up on the fixed shell, the axis of inlet opening and the axis of holding the chamber are coaxial and communicate with each other, the axis of apopore is perpendicular and communicate with each other with the axis of holding the chamber, the coaxial activity of first impeller sets up in the inside of holding the chamber, the slip direction of first impeller is parallel with the axis of holding the chamber, the first impeller sets up the position of keeping away from the motor, the coaxial activity of second impeller sets up in the inside of holding the chamber, the slip direction of second impeller is parallel with the axis of holding the chamber, second impeller and the output shaft drive connection of motor, the second impeller sets up in the position that is close to the motor, the second impeller can drive first impeller and the fixed setting of drainage pipeline is in the inside of holding the chamber, the one end setting of drainage pipeline is in inlet opening department, the other end setting up between second impeller and the second impeller orientation.

Preferably, the first impeller is coaxially and fixedly provided with a first fixed disc at two ends in the axial direction, the center of one surface of the first impeller, which is far away from the second impeller, is communicated with the outside, the two ends of the second impeller in the axial direction are coaxially and fixedly provided with a second fixed disc, and the center of one surface of the second impeller, which is far away from the first impeller, is communicated with the outside.

Preferably, the output shaft of the motor is provided with a connecting chute, the position of the second impeller, which is far away from the first impeller, is fixedly provided with a first limiting bar which is in sliding fit with the connecting chute, the length direction of the first limiting bar is parallel to the axis of the second impeller, the first impeller is coaxially and fixedly provided with a fixed shaft which extends towards the direction of the second impeller, the tail end of the fixed shaft is provided with a second limiting bar, one surface of the second impeller, which is close to the first impeller, is provided with a first fixing hole which is in sliding fit with the fixed shaft, and the inside of the first fixing hole is provided with a second fixing hole which can be clamped with the second limiting bar.

Preferably, the pump body further comprises a first spring, the two ends of the first spring are coaxially and fixedly provided with fixing rings, one surface of the first impeller, which is close to the second impeller, is provided with a first annular groove which is matched with the fixing rings to coaxially slide, and one surface of the second impeller, which is close to the first impeller, is provided with a second annular groove which is matched with the fixing rings to coaxially slide.

Preferably, the second limiting bar is in sliding connection with the fixed shaft, the sliding direction of the second limiting bar is parallel to the axis of the fixed shaft, a second spring is fixedly arranged between the second limiting bar and the fixed shaft, and the axis of the second spring is parallel to the sliding direction of the second limiting bar.

Preferably, the fixed shaft is fixedly provided with a limit bolt, the axis of the limit bolt is perpendicular to the axis of the fixed shaft, the second limit bar is provided with a limit chute matched with the limit bolt to slide, and the length direction of the limit chute is parallel to the sliding direction of the second limit bar.

Preferably, the pump body further comprises a third fixed disc, the third fixed disc is fixedly arranged between the motor and the second impeller, the third fixed disc is movably matched with an output shaft of the motor, a large annular protrusion and a small annular protrusion are coaxially and fixedly arranged on the third fixed disc, the drainage pipeline is fixedly connected with the outer wall of the large annular protrusion, the small annular protrusion and the second impeller form a temporary water storage cavity, and water output by the drainage pipeline can enter the temporary water storage cavity.

Preferably, the pump body further comprises a water inlet sleeve, the water inlet sleeve is coaxially and fixedly arranged in the water inlet hole, a diversion baffle is fixedly arranged at the center of the water inlet sleeve, and one end, close to the water inlet hole, of the drainage pipeline is communicated with the water inlet sleeve.

Preferably, the number of the drainage pipes is two, and all the drainage pipes are uniformly arranged around the axis of the accommodating cavity.

Preferably, the drainage pipeline is made of flexible materials.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the function of dividing water flow into two convection flows in the accommodating cavity through the drainage pipeline so as to offset axial force is realized, and the function that the first impeller and the second impeller cannot be extruded with other parts before the axial force between the two water flows is offset by each other is realized through the interval between the first impeller and the second impeller, so that friction loss cannot occur due to the axial force caused by the water flow at any moment in the using process of the whole device, and meanwhile, partial water flow for diversion can be stably discharged from the water outlet, and the service life of the whole device is prolonged.

Drawings

FIG. 1 is a schematic perspective view of an axial force self-balancing centrifugal pump;

FIG. 2 is a schematic cross-sectional view of a pump body in an axial force self-balancing centrifugal pump;

FIG. 3 is an enlarged schematic view of a portion of FIG. 2A;

FIG. 4 is a schematic cross-sectional view of a pump body in an axial force self-balancing centrifugal pump;

FIG. 5 is an enlarged partial schematic view of B in FIG. 4;

FIG. 6 is a schematic cross-sectional view of a pump body in an axial force self-balancing centrifugal pump;

FIG. 7 is an enlarged partial schematic view of C in FIG. 6;

FIG. 8 is a schematic exploded perspective view of a pump body of an axial force self-balancing centrifugal pump;

FIG. 9 is an enlarged partial schematic view of D in FIG. 8;

fig. 10 is a schematic exploded perspective view of a pump body in an axial force self-balancing centrifugal pump.

The reference numerals in the figures are:

1-a pump body;

11-a fixed shell; 111-a receiving cavity; 112-water inlet holes; 113-water outlet holes;

12-a first impeller; 121-a first fixed disk; 122-a fixed shaft; 123-a second limit bar; 124-a first annular groove; 125-a second spring; 126-limit bolts; 127-limiting sliding grooves;

13-a second impeller; 131-a second fixed disk; 132-a first limit bar; 133-a first fixing hole; 134-a second fixing hole;

135-a second annular groove;

14-a drainage pipeline;

15-a first spring; 151-a securing ring;

16-a third fixed disk; 161-annular projection; 162-temporary water storage chamber;

17-a water inlet sleeve; 171-split baffle;

2-motor.

Detailed Description

The invention will be further described in detail with reference to the drawings and the detailed description below, in order to further understand the features and technical means of the invention and the specific objects and functions achieved.

Referring to fig. 1, fig. 2, fig. 4 and fig. 8, an axial force self-balancing centrifugal pump comprises a pump body 1 and a motor 2, the pump body 1 comprises a fixed shell 11, a first impeller 12, a second impeller 13 and a drainage pipeline 14, a containing cavity 111 is formed in the fixed shell 11, the whole containing cavity 111 is cylindrical, an output shaft of the motor 2 is inserted into the containing cavity 111 and is coaxially arranged with the containing cavity 111, a water inlet hole 112 and a water outlet hole 113 are formed in the fixed shell 11, the axis of the water inlet hole 112 is coaxial and communicated with the axis of the containing cavity 111, the axis of the water outlet hole 113 is perpendicular to and is communicated with the axis of the containing cavity 111, a first impeller 12 is coaxially and movably arranged in the containing cavity 111, the sliding direction of the first impeller 12 is parallel to the axis of the containing cavity 111, the first impeller 12 is arranged at a position far away from the motor 2, the second impeller 13 is coaxially and movably arranged in the containing cavity 111, the sliding direction of the second impeller 13 is parallel to the axis of the containing cavity 111, the second impeller 13 is in transmission connection with the output shaft of the motor 2, the axis of the motor 112 is coaxially arranged with the second impeller 13 and is rotatably arranged at the other end of the drainage pipeline 14, which is close to the first impeller 13 and the drainage pipeline 14 and can be rotatably arranged between the first impeller and the second impeller 14 and the drainage pipeline 14.

A water pipe is connected at the water inlet 112, another water pipe is connected at the water outlet 113, then the motor 2 is started, the motor 2 works to drive the second impeller 13 to rotate, at the moment, the second impeller 13 rotates to drive the first impeller 12 to synchronously rotate, the first impeller 12 generates centrifugal force because of rotation, the centrifugal force sucks water flow from the water inlet 112 into the accommodating cavity 111, part of the water flow enters the drainage pipeline 14 in the moving process, the other part of the water flow is firstly contacted with the first impeller 12, so that the first impeller 12 slides along the self axis direction towards the direction close to the first impeller 12, and the water flow is contacted with the center of the first impeller 12 through the centrifugal force and then pushes the first impeller 12 to move, at the moment, part of the water flow entering the drainage pipeline 14 moves to the outlet of the drainage pipeline 14, so that the water flow is output to the center of the second impeller 13, at this time, the second impeller 13 will move along the axial direction thereof toward the direction approaching the first impeller 12, so that the first impeller 12 and the second impeller 13 will contact at the center of the accommodating cavity 111, and the water flow entering from the water inlet 112 will move toward the water outlet 113 through the first impeller 12 and the second impeller 13 respectively and then be discharged, compared with the prior art, the drainage pipe 14 of the present invention divides the water flow into two convection flows into two flows to counteract axial force, the axial force between the two flows is offset by the interval between the first impeller 12 and the second impeller 13, so that the first impeller 12 and the second impeller 13 will not be squeezed with other parts before the axial force between the two flows are offset each other, thereby ensuring that friction loss will not occur due to the axial force caused by the water flow at any time in the use of the whole device, and meanwhile, partial water flow for diversion can be stably discharged from the water outlet 113, so that the service life of the whole device is prolonged.

See fig. 8 and 10: the first impeller 12 is provided with a first fixed disk 121 coaxially and fixedly arranged at two ends in the axial direction, the center of one surface of the first impeller 12 far away from the second impeller 13 is communicated with the outside, the two ends of the second impeller 13 in the axial direction are provided with a second fixed disk 131 coaxially and fixedly arranged at two ends in the axial direction, and the center of one surface of the second impeller 13 far away from the first impeller 12 is communicated with the outside.

The motor 2 works to drive the second impeller 13 and the first impeller 12 to rotate, because of the centrifugal force generated by the rotation of the first impeller 12, water flow enters the accommodating cavity 111 from the water inlet 112, part of the water flow enters between the two first fixed disks 121 on the first impeller 12 again under the action of the centrifugal force, so that the water flow passing through the drainage pipeline 14 enters between the two second fixed disks 131 of the second impeller 13 under the action of the centrifugal force generated by the rotation of the second impeller 13 after leaving the drainage pipeline 14, and the part of the water flow moves along the diameter direction of the second impeller 13.

See fig. 3, 5, 7 and 9: the output shaft of the motor 2 is provided with a connecting chute, a first limiting strip 132 which is in sliding fit with the connecting chute is fixedly arranged at a position, far away from the first impeller 12, on the second impeller 13, the length direction of the first limiting strip 132 is parallel to the axis of the second impeller 13, a fixed shaft 122 which extends towards the direction of the second impeller 13 is coaxially and fixedly arranged on the first impeller 12, the tail end of the fixed shaft 122 is provided with a second limiting strip 123, a first fixing hole 133 which is in sliding fit with the fixed shaft 122 is formed in one surface, close to the first impeller 12, of the second impeller 13, and a second fixing hole 134 which can be connected with the second limiting strip 123 in a clamping mode is formed in the first fixing hole 133.

When the motor 2 works, the output shaft rotates, the first limiting bar 132 is clamped in the connecting chute, the second impeller 13 rotates along with the rotation of the output shaft, and at the moment, the second limiting hole is inserted into the second fixing hole 134, the first impeller 12 rotates along with the rotation of the second impeller 13, at the moment, centrifugal force is generated by the rotation of the first impeller 12 to suck water flow from the water inlet 112, one part of the water flow contacts with the first impeller 12 to generate axial force to push the first impeller 12 to move towards the direction close to the second impeller 13, the other part of the water flow moves to the surface, away from the first impeller 12, of the second impeller 13 through the drainage pipeline 14, and centrifugal force generated by the rotation of the second impeller 13 attracts the water flow to be close to the second impeller 13, so that the second impeller 13 moves towards the direction close to the first impeller 12.

See fig. 2 to 8: the pump body 1 further comprises a first spring 15, fixing rings 151 are coaxially and fixedly arranged at two ends of the first spring 15, a first annular groove 124 which is matched with the fixing rings 151 to coaxially slide is formed in one surface, close to the second impeller 13, of the first impeller 12, and a second annular groove 135 which is matched with the fixing rings 151 to coaxially slide is formed in one surface, close to the first impeller 12, of the second impeller 13.

The motor 2 works and before the water flow does not enter the accommodating cavity 111, the first spring 15 is in a normal state at this time, the first impeller 12 and the second impeller 13 are far away from each other, the second impeller 13 drives the first impeller 12 to rotate along with the work of the motor 2, when the motor 2 works to enable the water flow to enter the accommodating cavity 111, the first spring 15 is continuously compressed to provide elastic force for the first impeller 12 and the second impeller 13, the first impeller 12 and the second impeller 13 slowly move under the elastic force provided by the first spring 15 to avoid collision, when the motor 2 stops working, the first spring 15 is in a decompression state to provide elastic force for enabling the first impeller 12 and the second impeller 13 to be far away from each other, and compared with the prior art, the first spring 15 is positioned between the first impeller 12 and the second impeller 13 to provide elastic force for the first impeller 12 and the second impeller 13, so that the first impeller 12 and the second impeller 13 are prevented from approaching each other under the action of axial force.

See fig. 2-7: the second limiting strip 123 is slidably connected with the fixed shaft 122, the sliding direction of the second limiting strip 123 is parallel to the axis of the fixed shaft 122, a second spring 125 is fixedly arranged between the second limiting strip 123 and the fixed shaft 122, and the axis of the second spring 125 is parallel to the sliding direction of the second limiting strip 123.

When the motor 2 is not in operation, the second spring 125 is in a slightly compressed state, most of the second limiting bar 123 is outside the fixed shaft 122, the second limiting bar 123 is inserted into the second fixed hole 134, the first impeller 12 is rotated along with the rotation of the second impeller 13, when the motor 2 is operated to enable water flow to enter the accommodating cavity 111, the interval between the second impeller 13 and the first impeller 12 is continuously reduced, the second limiting bar 123 is continuously contracted inside the fixed shaft 122, the second spring 125 is continuously compressed to provide elastic force to enable the second limiting bar 123 to be still inserted into the second fixed hole 134, and at the moment, the first impeller 12 is still rotated along with the rotation of the second impeller 13, compared with the prior art, the second spring 125 provided elastic force to push the second limiting bar 123 to be inserted into the second fixed hole 134, so that the transmission connection between the second impeller 13 and the first impeller 12 is ensured to be stable.

See fig. 2 to 9: the fixed shaft 122 is fixedly provided with a limit bolt 126, the axis of the limit bolt 126 is perpendicular to the axis of the fixed shaft 122, the second limit bar 123 is provided with a limit chute 127 matched with the limit bolt 126 to slide, and the length direction of the limit chute 127 is parallel to the sliding direction of the second limit bar 123.

When the pump body 1 is maintained, the fixing shell 11 is disassembled, the first impeller 12 is removed from the second impeller 13, the second spring 125 in a slightly compressed state is in a decompressed state, one end of the second limit bar 123 far away from the first impeller 12 is not constrained, the elastic force provided by the second spring 125 enables the second limit bar 123 to move relatively with the first impeller 12, after the second limit bar 123 moves a certain distance, the limit bolt 126 contacts with the end of the limit chute 127 so that the second limit bar 123 stops moving, compared with the prior art, the limit bolt 126 and the limit chute 127 limit the moving range of the second limit bar 123, and therefore the second limit bar 123 is prevented from being disconnected with the first impeller 12 when the pump body 1 is disassembled.

See fig. 2, 4, 8 and 10: the pump body 1 further comprises a third fixed disc 16, the third fixed disc 16 is fixedly arranged between the motor 2 and the second impeller 13, the third fixed disc 16 is movably matched with an output shaft of the motor 2, a large annular protrusion 161 and a small annular protrusion 161 are coaxially and fixedly arranged on the third fixed disc 16, the drainage pipeline 14 is fixedly connected with the outer wall of the large annular protrusion 161, the small annular protrusion 161 and the second impeller 13 form a temporary water storage cavity 162, and water output by the drainage pipeline 14 can enter the temporary water storage cavity 162.

The motor 2 works to drive the second impeller 13 and the first impeller 12 to rotate simultaneously, a part of water flow entering from the water inlet 112 due to the centrifugal force generated by the rotation of the first impeller 12 enters the back of the first impeller 12, another part of water flow entering from the water inlet 112 due to the centrifugal force generated by the rotation of the first impeller 12 enters the drainage pipeline 14, at the moment, the part of water flow leaves from the drainage pipeline 14 and enters the temporary water storage cavity 162, so that the part of water flow is concentrated, the second impeller 13 at the moment, due to the centrifugal force generated by the rotation, the water flow in the temporary water storage cavity 162 enters between the two second fixed discs 131, and compared with the prior art, the third fixed disc 16 of the invention concentrates the water flow output from the drainage pipeline 14, so that the centrifugal force generated by the rotation of the second impeller 13 is convenient to attract the part of water flow.

See fig. 4-5, 8 and 10: the pump body 1 further comprises a water inlet sleeve 17, the water inlet sleeve 17 is coaxially and fixedly arranged in the water inlet hole 112, a diversion baffle 171 is fixedly arranged at the center of the water inlet sleeve 17, and one end, close to the water inlet hole 112, of the drainage pipeline 14 is communicated with the water inlet sleeve 17.

The centrifugal force generated by the rotation of the first impeller 12 will cause the water flow to enter from the water inlet 112, then the water flow of this part will be divided into two parts by the operation of the split baffle 171, one part will continue to move so as to enter into the interior of the first impeller 12 and be discharged by the centrifugal force generated by the rotation of the first impeller 12, the other part will enter into the temporary water storage cavity through the drainage pipe 14, then this part of the water flow enters into the second impeller 13 and is discharged by the centrifugal force generated by the rotation of the second impeller 13, compared with the prior art, the water inlet sleeve 17 of the present invention causes the water flow passing through the water inlet 112 to be divided into two parts uniformly, so that the axial force suffered by the first impeller 12 and the second impeller 13 is kept the same all the time.

See fig. 2, 4, 6, 8 and 10: the number of the drainage pipes 14 is two, and all the drainage pipes 14 are uniformly arranged around the axis of the accommodating chamber 111.

Due to the centrifugal force generated by the rotation of the first impeller 12, water flows are continuously sucked from the water inlet 112, and the water flows enter the water inlet sleeve 17 to be split by the split baffle 171, part of the water flows split by the split baffle 171 are continuously input into the temporary water storage cavity 162 along the two drainage pipelines 14, and the second impeller 13 rotates to generate centrifugal force so that the part of the water flows enter the second impeller 13.

See fig. 8 and 10: the drainage tube 14 is made of flexible material.

The inner wall of the fixed shell 11 is provided with a groove capable of placing the drainage pipeline 14, the drainage pipeline 14 is placed into the groove and pressed when being installed, the drainage pipeline 14 is fully attached to the groove left on the inner wall of the containing cavity 111, so that the diameter of a cylindrical cavity formed by the containing cavity 111 is the same as that of the first impeller 12, and compared with the prior art, the drainage pipeline 14 is made of a flexible material, so that the drainage pipeline 14 can be fully attached to avoid unnecessary grooves.

The foregoing examples merely illustrate one or more embodiments of the invention, which are described in greater detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (10)

1. An axial force self-balancing centrifugal pump comprises a pump body (1) and a motor (2), and is characterized in that the pump body (1) comprises a fixed shell (11), a first impeller (12), a second impeller (13) and a drainage pipeline (14);

the inside of the fixed shell (11) is provided with a containing cavity (111), the containing cavity (111) is integrally cylindrical, an output shaft of the motor (2) is inserted into the containing cavity (111) and is coaxially arranged with the containing cavity (111), the fixed shell (11) is provided with a water inlet hole (112) and a water outlet hole (113), the axis of the water inlet hole (112) is coaxial and communicated with the axis of the containing cavity (111), and the axis of the water outlet hole (113) is perpendicular and communicated with the axis of the containing cavity (111);

the first impeller (12) is coaxially and movably arranged in the accommodating cavity (111), the sliding direction of the first impeller (12) is parallel to the axis of the accommodating cavity (111), the rotating shaft of the first impeller (12) is coaxial with the axis of the accommodating cavity (111), and the first impeller (12) is arranged at a position far away from the motor (2);

the second impeller (13) is coaxially and movably arranged in the accommodating cavity (111), the sliding direction of the second impeller (13) is parallel to the axis of the accommodating cavity (111), the second impeller (13) is in transmission connection with the output shaft of the motor (2), the second impeller (13) is arranged at a position close to the motor (2), and the second impeller (13) can drive the first impeller (12) to rotate;

the drainage pipeline (14) is fixedly arranged in the accommodating cavity (111), one end of the drainage pipeline (14) is arranged at the water inlet hole (112), and the other end of the drainage pipeline (14) is arranged between the second impeller (13) and the motor (2) and faces the second impeller (13).

2. An axial force self-balancing centrifugal pump according to claim 1, wherein a first fixing disc (121) is coaxially and fixedly arranged at both ends of the first impeller (12) in the axial direction, the center of a surface of the first impeller (12) far away from the second impeller (13) is communicated with the outside, a second fixing disc (131) is coaxially and fixedly arranged at both ends of the second impeller (13) in the axial direction, and the center of a surface of the second impeller (13) far away from the first impeller (12) is communicated with the outside.

3. The axial force self-balancing centrifugal pump according to claim 2, wherein a connecting chute is formed in an output shaft of the motor (2), a first limiting bar (132) which is in sliding fit with the connecting chute is fixedly arranged at a position, far away from the first impeller (12), of the second impeller (13), the length direction of the first limiting bar (132) is parallel to the axis of the second impeller (13), a fixed shaft (122) extending towards the direction of the second impeller (13) is fixedly arranged on the first impeller (12) in a coaxial manner, a second limiting bar (123) is arranged at the tail end of the fixed shaft (122), a first fixing hole (133) which is in sliding fit with the fixed shaft (122) is formed in one surface, close to the first impeller (12), of the second impeller (13), and a second fixing hole (134) which can be clamped with the second limiting bar (123) is formed in the first fixing hole (133).

4. An axial force self-balancing centrifugal pump according to claim 3, wherein the pump body (1) further comprises a first spring (15);

both ends of the first spring (15) are coaxially and fixedly provided with fixing rings (151), one surface of the first impeller (12) close to the second impeller (13) is provided with a first annular groove (124) which is matched with the fixing rings (151) to coaxially slide, and one surface of the second impeller (13) close to the first impeller (12) is provided with a second annular groove (135) which is matched with the fixing rings (151) to coaxially slide.

5. The axial force self-balancing centrifugal pump according to claim 4, wherein the second limiting bar (123) is slidably connected to the fixed shaft (122), the sliding direction of the second limiting bar (123) is parallel to the axis of the fixed shaft (122), a second spring (125) is fixedly arranged between the second limiting bar (123) and the fixed shaft (122), and the axis of the second spring (125) is parallel to the sliding direction of the second limiting bar (123).

6. The axial force self-balancing centrifugal pump according to claim 5, wherein a limiting bolt (126) is fixedly arranged on the fixed shaft (122), the axis of the limiting bolt (126) is perpendicular to the axis of the fixed shaft (122), a limiting chute (127) matched with the sliding of the limiting bolt (126) is formed in the second limiting strip (123), and the length direction of the limiting chute (127) is parallel to the sliding direction of the second limiting strip (123).

7. An axial force self-balancing centrifugal pump according to claim 6, wherein the pump body (1) further comprises a third fixed disk (16);

the third fixed disk (16) is fixedly arranged between the motor (2) and the second impeller (13), the third fixed disk (16) is movably matched with an output shaft of the motor (2), a large annular protrusion (161) and a small annular protrusion (161) are coaxially and fixedly arranged on the third fixed disk (16), the drainage pipeline (14) is fixedly connected with the outer wall of the large annular protrusion (161), the small annular protrusion (161) and the second impeller (13) form a temporary water storage cavity (162), and water output by the drainage pipeline (14) can enter the temporary water storage cavity (162).

8. An axial force self-balancing centrifugal pump according to claim 7, wherein the pump body (1) further comprises a water inlet sleeve (17);

the water inlet sleeve (17) is coaxially and fixedly arranged in the water inlet hole (112), a diversion baffle (171) is fixedly arranged at the center of the water inlet sleeve (17), and one end, close to the water inlet hole (112), of the diversion pipeline (14) is communicated with the water inlet sleeve (17).

9. An axial force self-balancing centrifugal pump according to claim 8, wherein the number of drainage ducts (14) is two, all the drainage ducts (14) being evenly arranged around the axis of the receiving chamber (111).

10. An axial force self-balancing centrifugal pump according to claim 9, wherein the two drainage pipes (14) are of flexible material.