CN114542474B

CN114542474B - Centrifugal urea pump

Info

Publication number: CN114542474B
Application number: CN202210447632.7A
Authority: CN
Inventors: 高居顺; 高世亮; 侯政
Original assignee: Yantai Luji Automobile Technology Co ltd
Current assignee: Yantai Luji Automobile Technology Co ltd
Priority date: 2022-04-25
Filing date: 2022-04-25
Publication date: 2022-07-01
Anticipated expiration: 2042-04-25
Also published as: CN114542474A

Abstract

The invention discloses a centrifugal urea pump, which relates to the technical field of urea filling pumps and comprises a pump shell and a fixed shell, wherein a partition plate is arranged in the pump shell, the inner space of the pump shell is divided into a containing cavity and a liquid inlet cavity by the partition plate, a liquid inlet and a liquid outlet are arranged on the pump shell, a driving mechanism is arranged in the fixed shell, the driving mechanism comprises a rotary driving assembly, a fixed driving assembly and a driving shaft, a shifting adjusting assembly and a fixed assembly are arranged at one end of the driving shaft, a first impeller and a second impeller are arranged on the shifting assembly, a shell cover is arranged in the containing cavity, the shell cover is respectively and fixedly connected with the partition plate and the pump shell, a connecting port is arranged on one side of the shell cover, a first mounting cavity, a second mounting cavity and a buffer cavity are arranged in the shell cover, a connecting pipe is arranged outside the shell cover, and a through hole is arranged on the shell cover. The invention can carry out fine adjustment according to the stress conditions of the first impeller and the second impeller, prolongs the service life of the equipment, and is fixed through the fixing component after fine adjustment, thereby further prolonging the service life of the equipment.

Description

Centrifugal urea pump

Technical Field

The invention relates to the technical field of urea filling pumps, in particular to a centrifugal urea pump.

Background

The invention discloses a centrifugal urea pump, which is a common automobile accessory and comprises a centrifugal pump body, a connecting device and the like, wherein a pump shell is provided with a liquid inlet pipe and a liquid outlet pipe; the urea filling pump comprises a first impeller and a second impeller, wherein two external threads are arranged on a driving shaft, and the first impeller and the second impeller are symmetrically distributed, so that axial forces borne by the first impeller and the second impeller are opposite, when the first impeller and the second impeller move, a first nut moves together and forms threaded transmission with the external threads on the driving shaft, the mounting position of the first nut relative to a second nut is changed, the solution flow at the inlet of the first impeller or the second impeller is changed, the axial forces borne by the first impeller and the second impeller are the same in magnitude and opposite in direction, and redundant axial forces are counteracted.

However, the above patents have the following disadvantages in use: the motion cover can not be fixed in the above patent, even through the mutual offset relative balance of two impeller effects when using, this kind of balance can not keep continuously, and that is to say, the motion cover slightly slides about can be continuous in the use, consequently, can lead to the wearing and tearing of equipment serious, reduces the life of equipment.

Disclosure of Invention

The invention aims to provide a centrifugal urea pump to solve the technical problems that equipment cannot be fixed and is seriously abraded to cause short service life of the equipment in the prior art.

The invention provides a centrifugal urea pump, which comprises a pump shell and a fixed shell which are adjacently arranged, wherein a partition plate is arranged in the pump shell, the inner space of the pump shell is divided into an accommodating cavity and a liquid inlet cavity by the partition plate, a liquid inlet and a liquid outlet are arranged on the pump shell, a driving mechanism is arranged in the fixed shell, the driving mechanism comprises a rotary driving assembly, a fixed driving assembly and a driving shaft, one end of the driving shaft penetrates through the pump shell and extends into the accommodating cavity, the rotary driving assembly and the fixed driving assembly are in transmission fit with the driving shaft, one end of the driving shaft, which is positioned in the accommodating cavity, is provided with a shifting adjusting assembly and a fixed assembly, the fixed assembly is matched with the fixed driving assembly, the shifting adjusting assembly is provided with a first impeller and a second impeller, a shell cover is arranged in the accommodating cavity, one end of the driving shaft penetrates through the shell cover and is rotatably connected with the shell cover, the utility model discloses a pump shell, including the shell, baffle and pump case, the shell is equipped with the connector respectively with baffle and pump case fixed connection, one side of shell orientation feed liquor chamber is equipped with the connector, be equipped with first installation cavity, second installation cavity and cushion chamber in the shell, first impeller and second impeller set up respectively in first installation cavity and second installation cavity, the cushion chamber sets up between first installation cavity and second installation cavity, the shell outside is equipped with the connecting pipe that is used for communicateing first installation cavity and second installation cavity, be equipped with the through-hole that is used for communicateing the second installation cavity and holds the cavity on the shell.

Further, the drunkenness adjusting part includes the sliding sleeve, the sliding sleeve cover is established in the drive shaft and can follow endwise slip between the two, the inside of sliding sleeve is equipped with a plurality of slider, be equipped with a plurality of spout in the drive shaft, the slider is with the spout sliding fit who corresponds, the middle part cover of sliding sleeve is equipped with the buffer block rather than rotating the connection, the both sides of buffer block all are equipped with buffer spring, buffer block and buffer spring all set up in the buffer cavity, every buffer spring keeps away from the one end of buffer block and all contradicts with the clamshell.

Further, the second impeller includes first rim plate, second rim plate, the first blade of a plurality of and a plurality of second blade, first rim plate and slip cover fixed connection, second rim plate and drive shaft fixed connection, the first blade of a plurality of are the circumference and distribute on first rim plate, and a plurality of second blade is the circumference and distributes on the second rim plate, and when first rim plate and second rim plate were close to each other, one side of first blade was laminated with one side of the second blade that corresponds.

Further, the width of the first blade is the same as that of the second blade, and the width of the first blade is smaller than that of the first impeller.

Further, fixed subassembly includes the intercommunication chamber, the intercommunication chamber sets up in the drive shaft, the drive shaft is equipped with the fixed chamber of a plurality of and spout one-to-one, the bottom intercommunication of fixed chamber and spout, fixed intracavity is equipped with and can follows the fixed piece of supporting of drive shaft radial slip, the slider extends to fixed intracavity, every all be equipped with between fixed chamber and the intercommunication chamber and be connected the chamber, connect the intracavity be equipped with rather than sliding fit's connecting block, the connecting block is connected with fixed piece of supporting, the width in fixed chamber is greater than the spout and is connected the width in chamber.

Further, fixed drive assembly includes the connecting portion of being connected with the sealed rotation of drive shaft, connecting portion fixed mounting is in the set casing, the centre of connecting portion is equipped with the piston chamber with the intercommunication chamber intercommunication, sliding connection has the drive piston in the piston chamber, the one end of connecting portion is equipped with electric putter, electric putter's output and drive piston fixed connection.

Further, the rotary driving assembly comprises a driving gear, a driven gear, a speed reducer and a driving motor, the driving gear is sleeved on the output end of the speed reducer, the driven gear is sleeved on one end of the driving shaft in the fixed shell, the driven gear is meshed with the driving gear, the driving motor is fixedly installed in the fixed shell, and the output end of the driving motor is fixedly connected with the input end of the speed reducer.

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

(1) through fixed drive assembly work, fix the drunkenness adjustment assembly through fixed subassembly, on the one hand, the drunkenness adjustment assembly has accomplished regulation work to first impeller and second impeller, can make steady operation between the two, improve equipment's life, on the other hand, fixed subassembly fixes the back to the drunkenness adjustment assembly, even the thrust of axial displacement between first impeller and the second impeller continuously takes place slight change, influence this moment also has been very little, and can prevent that the drunkenness adjustment assembly from continuously moving the friction, equipment's life has further been guaranteed.

(2) The thrust force applied to the second impeller is changed by influencing the flow speed of the feed liquid through the width between the first wheel disc and the second wheel disc in the second blade, and a further adjusting effect is achieved.

(3) When first rim plate and second rim plate are in the maximum distance, distance between the two is greater than the distance of two rim plates in first impeller, when first rim plate and second rim plate are in the minimum distance, first blade and second blade overlap, and distance between first rim plate and the second rim plate is less than the distance of two rim plates in the first impeller, and above-mentioned structure makes the control range of second impeller great for drunkenness adjusting part's regulation nature is stronger, and the suitability is wider.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a partial side view of the present invention;

FIG. 3 is a partial top view of the first embodiment of the present invention;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3;

FIG. 5 is an enlarged view at B in FIG. 4;

FIG. 6 is a partial perspective view of the present invention;

FIG. 7 is a second partial top view of the present invention;

FIG. 8 is a cross-sectional view taken along line C-C of FIG. 7;

FIG. 9 is a partial top view of the third embodiment of the present invention;

fig. 10 is a cross-sectional view taken along line D-D of fig. 9.

Reference numerals:

1. a pump housing; 2. a stationary case; 3. a partition plate; 4. an accommodating chamber; 5. a liquid inlet cavity; 6. a liquid inlet; 7. a liquid outlet; 8. a rotary drive assembly; 81. a driving gear; 82. a driven gear; 83. a speed reducer; 84. a drive motor; 9. fixing the driving component; 91. a connecting portion; 92. a piston cavity; 93. a drive piston; 94. an electric push rod; 10. a drive shaft; 11. a play adjustment assembly; 111. a sliding sleeve; 112. a slider; 113. a chute; 114. a buffer block; 115. a buffer spring; 12. a fixing assembly; 121. a cavity is communicated; 122. a fixed cavity; 123. fixing the butting block; 124. a connecting cavity; 125. connecting blocks; 13. a first impeller; 14. a second impeller; 141. a first wheel disc; 142. a second wheel disc; 143. a first blade; 144. a second blade; 15. a housing; 151. a first mounting cavity; 152. a second mounting cavity; 153. a buffer chamber; 16. a connecting port; 17. a connecting pipe; 18. and a through hole.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention.

The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.

All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1 to 10, an embodiment of the present invention provides a centrifugal urea pump, including a pump housing 1 and a fixed housing 2, which are adjacently disposed, a partition plate 3 is disposed in the pump housing 1, an internal space of the pump housing 1 is partitioned into an accommodating chamber 4 and a liquid inlet chamber 5 by the partition plate 3, a liquid inlet 6 and a liquid outlet 7 are disposed on the pump housing 1, a driving mechanism is disposed in the fixed housing 2, the driving mechanism includes a rotary driving component 8, a fixed driving component 9 and a driving shaft 10, one end of the driving shaft 10 penetrates through the pump housing 1 and extends into the accommodating chamber 4, the rotary driving component 8 and the fixed driving component 9 are both in transmission fit with the driving shaft 10, one end of the driving shaft 10 located in the accommodating chamber 4 is disposed with a play adjusting component 11 and a fixed component 12, the fixed component 12 is matched with the fixed driving component 9, the play adjusting component 11 is disposed with a first impeller 13 and a second impeller 14, hold the intracavity 4 and be equipped with the clamshell 15, the one end of drive shaft 10 runs through clamshell 15 and rotates with clamshell 15 to be connected, clamshell 15 respectively with baffle 3 and pump case 1 fixed connection, clamshell 15 is equipped with connector 16 towards one side of feed liquor chamber 5, be equipped with first installation cavity 151, second installation cavity 152 and cushion chamber 153 in the clamshell 15, first impeller 13 and second impeller 14 set up respectively in first installation cavity 151 and second installation cavity 152, cushion chamber 153 sets up between first installation cavity 151 and second installation cavity 152, clamshell 15 outside is equipped with the connecting pipe 17 that is used for communicateing first installation cavity 151 and second installation cavity 152, be equipped with the through-hole 18 that is used for communicateing second installation cavity 152 and holds chamber 4 on the clamshell 15. During operation, the rotation driving assembly 8 operates to drive the driving shaft 10 to rotate, the driving shaft 10 drives the first impeller 13 and the second impeller 14 to rotate to perform liquid pumping and conveying operations, the solution enters from the liquid inlet 6 and enters the first installation cavity 151 through the connecting port 16, is accelerated by the first impeller 13 and enters the second installation cavity 152 through the connecting pipe 17, is accelerated by the second impeller 14 and is discharged from the through hole 18, and is finally discharged from the liquid outlet 7, so as to realize the processes of liquid pumping and accelerated output, which is the prior art, while in operation, the first impeller 13 and the second impeller 14 generate axial moving thrust due to the turbulent flow of the liquid, although the thrust generated by the first impeller 13 and the second impeller 14 can cancel out a part of each other due to the opposite arrangement directions of the first impeller 13 and the second impeller 14, due to the difference of the liquid inlet speed and the liquid flow rate, the thrust difference between the first impeller 13 and the second impeller 14 inevitably exists, at this time, the thrust generated by the first impeller 13 and the second impeller 14 can be basically offset by adjusting through the position movement of the play adjusting component 11 and the matching work of the buffer component, however, because the liquid is conveyed by the invention, the thrust generated by the first impeller 13 and the second impeller 14 can not be ensured to be constant all the time, and then the play adjusting component 11 is fixed through the fixing component 12 through the work of the fixing driving component 9, on one hand, the play adjusting component 11 completes the adjusting work of the first impeller 13 and the second impeller 14, can enable the stable operation between the two, and improve the service life of the equipment, on the other hand, after the fixing component 12 fixes the play adjusting component 11, even if the thrust of the axial movement between the first impeller 13 and the second impeller 14 continuously slightly changes, the influence at this time is very small, the device is stably operated for 5-10 seconds after being started, the movement adjusting component 11 is basically and preliminarily adjusted, the movement adjusting component 11 is fixed through the fixing component 12 through the fixing driving component 9, stable operation of the device is achieved, if output power of the urea pump changes, the fixing component 12 is driven to be loosened, the device stably operates for 5-10 seconds again, the movement adjusting component 11 can complete adjustment again, the fixing component 12 fixes the movement adjusting component 11 through the fixing driving component 9, and a corresponding PLC control system can be set to operate in the process, so that operation of the device is simpler and more convenient.

Specifically, the play adjusting part 11 includes sliding sleeve 111, sliding sleeve 111 cover is established on drive shaft 10 and can be followed the axial slip between the two, sliding sleeve 111's inside is equipped with a plurality of slider 112, be equipped with a plurality of spout 113 on the drive shaft 10, slider 112 and the 113 sliding fit of spout that corresponds, sliding sleeve 111's middle part cover is equipped with buffer block 114 rather than rotating the connection, buffer block 114's both sides all are equipped with buffer spring 115, buffer block 114 and buffer spring 115 all set up in buffer chamber 153, every buffer spring 115 keeps away from buffer block 114's one end and all contradicts with housing 15, and buffer spring 115's effect plays the cushioning effect to the regulation of play adjusting part 11 to after the stop work, can make play adjusting part 11 can resume original position.

Specifically, the second impeller 14 includes a first wheel disc 141, a second wheel disc 142, a plurality of first blades 143, and a plurality of second blades 144, the first wheel disc 141 is fixedly connected to the sliding sleeve 111, the second wheel disc 142 is fixedly connected to the driving shaft 10, the plurality of first blades 143 are circumferentially distributed on the first wheel disc 141, the plurality of second blades 144 are circumferentially distributed on the second wheel disc 142, and when the first wheel disc 141 and the second wheel disc 142 are close to each other, one side of each first blade 143 is attached to one side of the corresponding second blade 144; in specific operation, the thrust applied to the second impeller 14 can be changed by influencing the flow rate of the feed liquid through the width between the first disk 141 and the second disk 142 in the second blade 144, so as to achieve a further regulation effect. For example, when the thrust force applied to the first impeller 13 is large, the motion adjusting assembly 11, the first wheel disc 141 and the first blades 143 on the first wheel disc 141 are pushed to move towards the second wheel disc 142, the distance between the first wheel disc 141 and the second wheel disc 142 is reduced, and since the liquid inlet flow rate is unchanged, the liquid inlet speed is inevitably increased, so that the force applied to the first wheel disc 141 in the second impeller 14 is increased towards the first impeller 13, and the first wheel disc gradually reaches a balanced state, and vice versa.

Specifically, the widths of the first blade 143 and the second blade 144 are the same and are both smaller than the width of the blade in the first impeller 13, so that when the first wheel disc 141 and the second wheel disc 142 are at the maximum distance, the distance between the first blade 143 and the second blade 142 is greater than the distance between the two wheel discs in the first impeller 13, when the first wheel disc 141 and the second wheel disc 142 are at the minimum distance, the first blade 143 and the second blade 144 overlap, and the distance between the first wheel disc 141 and the second wheel disc 142 is smaller than the distance between the two wheel discs in the first impeller 13, and by the structure, the adjusting range of the second impeller 14 is larger, so that the adjustability of the play adjusting assembly 11 is stronger, and the applicability is wider.

Specifically, the fixing assembly 12 includes a communicating cavity 121, the communicating cavity 121 is disposed in the driving shaft 10, the driving shaft 10 is provided with a plurality of fixing cavities 122 corresponding to the sliding grooves 113 one by one, the fixing cavities 122 are communicated with the bottoms of the sliding grooves 113, fixing abutting blocks 123 capable of sliding along the radial direction of the driving shaft 10 are disposed in the fixing cavities 122, the sliding blocks 112 extend into the fixing cavities 122, a connecting cavity 124 is disposed between each fixing cavity 122 and the communicating cavity 121, a connecting block 125 in sliding fit with the connecting cavity 124 is disposed in the connecting cavity 124, the connecting block 125 is connected with the fixing abutting blocks 123, and the width of the fixing cavity 122 is greater than the widths of the sliding grooves 113 and the connecting cavity 124.

Specifically, fixed drive assembly 9 includes the connecting portion 91 of being connected with the sealed rotation of drive shaft 10, connecting portion 91 fixed mounting is in set casing 2, the centre of connecting portion 91 is equipped with the piston chamber 92 with intercommunication chamber 121 intercommunication, sliding connection has drive piston 93 in the piston chamber 92, the one end of connecting portion 91 is equipped with electric putter 94, electric putter 94's output and drive piston 93 fixed connection.

During specific work, the electric push rod 94 pushes the driving piston 93 to move towards the communicating cavity 121, so that hydraulic oil in the communicating cavity 121 is extruded, all the connecting blocks 125 are extruded through the hydraulic oil, the fixed abutting blocks 123 outwardly extend and abut against all the sliding blocks 112, the moving adjusting assembly 11 is fixed, the moving adjusting assembly 11 is prevented from continuously working in the working process, the abrasion is serious, and the service life of the device is prolonged.

Specifically, rotation driving assembly 8 includes driving gear 81, driven gear 82, reduction gear 83 and driving motor 84, the output at reduction gear 83 is established to driving gear 81 cover, driven gear 82 cover is established and is served and driven gear 82 and driving gear 81 meshing in drive shaft 10 is located set casing 2, driving motor 84 fixed mounting is in set casing 2 and driving motor 84's output and reduction gear 83's input fixed connection, drives driving gear 81 through driving motor 84 work and under reduction gear 83's conduction and rotates, and driving gear 81 passes through driven gear 82 and drives drive shaft 10 and rotate.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a centrifugal urea pump, includes pump case (1) and set casing (2) of adjacent setting, be equipped with baffle (3) in pump case (1), the inner space of pump case (1) is separated through baffle (3) and is held chamber (4) and feed liquor chamber (5), be equipped with inlet (6) and liquid outlet (7) on pump case (1), its characterized in that: the improved pump is characterized in that a driving mechanism is arranged in the fixed shell (2), the driving mechanism comprises a rotary driving assembly (8), a fixed driving assembly (9) and a driving shaft (10), one end of the driving shaft (10) penetrates through the pump shell (1) and extends into the accommodating cavity (4), the rotary driving assembly (8) and the fixed driving assembly (9) are in transmission fit with the driving shaft (10), one end of the driving shaft (10) located in the accommodating cavity (4) is provided with a play adjusting assembly (11) and a fixed assembly (12), the fixed assembly (12) is matched with the fixed driving assembly (9), the play adjusting assembly (11) is provided with a first impeller (13) and a second impeller (14), a shell cover (15) is arranged in the accommodating cavity (4), one end of the driving shaft (10) penetrates through the shell cover (15) and is rotatably connected with the shell cover (15), the shell cover (15) is fixedly connected with the partition plate (3) and the pump shell (1) respectively, a connecting port (16) is formed in one side, facing the liquid inlet cavity (5), of the shell cover (15), a first installation cavity (151), a second installation cavity (152) and a buffer cavity (153) are formed in the shell cover (15), the first impeller (13) and the second impeller (14) are arranged in the first installation cavity (151) and the second installation cavity (152) respectively, the buffer cavity (153) is arranged between the first installation cavity (151) and the second installation cavity (152), a connecting pipe (17) used for communicating the first installation cavity (151) with the second installation cavity (152) is arranged outside the shell cover (15), and a through hole (18) used for communicating the second installation cavity (152) with the accommodating cavity (4) is formed in the shell cover (15); the play adjusting assembly (11) comprises a sliding sleeve (111), the sliding sleeve (111) is sleeved on the driving shaft (10) and can slide axially between the driving shaft and the driving shaft, a plurality of sliding blocks (112) are arranged inside the sliding sleeve (111), a plurality of sliding grooves (113) are formed in the driving shaft (10), the sliding blocks (112) are in sliding fit with the corresponding sliding grooves (113), a buffer block (114) rotatably connected with the sliding sleeve (111) is sleeved in the middle of the sliding sleeve (111), buffer springs (115) are arranged on two sides of the buffer block (114), the buffer block (114) and the buffer springs (115) are arranged in a buffer cavity (153), and one end, far away from the buffer block (114), of each buffer spring (115) is abutted against the shell cover (15); the fixing assembly (12) comprises a communicating cavity (121), the communicating cavity (121) is arranged in a driving shaft (10), the driving shaft (10) is provided with a plurality of fixing cavities (122) which correspond to the sliding grooves (113) one by one, the fixing cavities (122) are communicated with the bottoms of the sliding grooves (113), fixing abutting blocks (123) which can slide along the radial direction of the driving shaft (10) are arranged in the fixing cavities (122), the sliding blocks (112) extend into the fixing cavities (122), a connecting cavity (124) is arranged between each fixing cavity (122) and the communicating cavity (121), connecting blocks (125) which are in sliding fit with the connecting cavity (124) are arranged in the connecting cavity (124), the connecting blocks (125) are connected with the fixing abutting blocks (123), and the width of the fixing cavities (122) is greater than the widths of the sliding grooves (113) and the connecting cavities (124); the fixed driving assembly (9) comprises a connecting part (91) in sealed rotary connection with the driving shaft (10), the connecting part (91) is fixedly installed in the fixed shell (2), a piston cavity (92) communicated with the communicating cavity (121) is arranged in the middle of the connecting part (91), a driving piston (93) is connected in the piston cavity (92) in a sliding mode, an electric push rod (94) is arranged at one end of the connecting part (91), and the output end of the electric push rod (94) is fixedly connected with the driving piston (93); second impeller (14) include first rim plate (141), second rim plate (142), a plurality of first blade (143) and a plurality of second blade (144), first rim plate (141) and slip cap (111) fixed connection, second rim plate (142) and drive shaft (10) fixed connection, a plurality of first blade (143) are the circumference and distribute on first rim plate (141), and a plurality of second blade (144) are the circumference and distribute on second rim plate (142), and when first rim plate (141) and second rim plate (142) were close to each other, one side of first blade (143) was laminated with one side of the second blade (144) that corresponds.

2. A centrifugal urea pump according to claim 1, characterized in that: the width of the first blade (143) and the width of the second blade (144) are the same and are both smaller than the width of the blades in the first impeller (13).

3. A centrifugal urea pump according to claim 1, characterized in that: rotatory drive assembly (8) include driving gear (81), driven gear (82), reduction gear (83) and driving motor (84), the output at reduction gear (83) is established to driving gear (81) cover, driven gear (82) cover establish drive shaft (10) be located one of set casing (2) serve and driven gear (82) and driving gear (81) meshing, driving motor (84) fixed mounting is in set casing (2) and the output of driving motor (84) and the input fixed connection of reduction gear (83).