Fixing structure for central shaft of magnetic drive pump

Abstract

The utility model provides a fixing structure for a central shaft of a magnetic drive pump, and belongs to the technical field of pumps. The fixing structure of the magnetic drive pump center shaft comprises a shell, the center shaft, an impeller, a rotor assembly and a stator assembly are arranged in the shell, the rotor assembly and the stator assembly are integrated through injection molding, the rotor assembly is provided with an annular inner cavity, the stator assembly comprises a stator part and an installation part, the stator part is located in the annular inner cavity, and the impeller and the rotor assembly are detachably fixed. A guide vane opposite to the water inlet is integrally formed in the shell and provided with a first fixing hole with a downward opening, a through hole consistent with the central axis of the annular inner cavity is formed in the middle of the rotor assembly, the mounting part is provided with a second fixing hole, the center shaft penetrates through the through hole, and the two ends of the center shaft are embedded into the first fixing hole and the second fixing hole to be fixed. According to the utility model, rotary parts are reduced, and the central shaft can be stably and conveniently mounted.

Description

Technical Field

[0001] The utility model belongs to the technical field of pumps, in particular to a fixing structure of a central axis of a magnetic pump. Background Art

[0002] The magnetic pump includes an impeller and an outer rotor motor that drives the impeller to rotate. The outer rotor motor includes a stator assembly and a rotor assembly. The rotor assembly is formed as a whole with an inner cavity by plastic injection molding. The stator assembly is formed as a whole by plastic injection molding and is arranged in the inner cavity of the rotor assembly. The rotor assembly is fixed to the central shaft, and the impeller is fixed on the central shaft. The rotation of the outer rotor motor drives the central shaft to rotate to drive the impeller to rotate.

[0003] In an existing permanent magnet outer rotor submersible electric pump (application number: 2020115946276) disclosed in the China Patent Library, the rotor is mounted on the rotating shaft through a rotor bracket. The rotor bracket is provided with a plurality of blades. An inlet end bearing and an outlet end bearing are respectively provided at both ends of the rotating shaft. The rotating shaft is rotated and fixed by the bearings at both ends. The rotation of the rotor drives the rotating shaft to drive the blades to rotate.

[0004] Such a magnetic pump has more rotating parts driven by the outer rotor motor, which increases the kinetic energy loss and reduces the working efficiency of the pump. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the utility model is to provide a fixing structure of the central shaft of a magnetic pump. The technical problem to be solved by the utility model is how to reduce the number of rotating parts and install the central shaft stably and conveniently.

[0006] The purpose of the utility model can be achieved through the following technical solutions: a fixing structure of the central axis of a magnetic pump, the magnetic pump includes a shell with a water inlet and a water outlet, the shell is provided with a central axis, an impeller, a rotor assembly and a stator assembly which are injection-molded into one, the rotor assembly has an annular inner cavity, the stator assembly includes a stator part and a mounting part, the stator part is in the annular inner cavity, the impeller and the rotor assembly are detachable and fixed, a guide vane which is opposite to the water inlet position is integrally formed in the shell, the guide vane is provided with a fixing hole 1 which opens downward, a through hole which is consistent with the central axis of the annular inner cavity is provided in the middle of the rotor assembly, the mounting part is provided with a fixing hole 2 which opens upward, the central axis passes through the through hole, and the two ends of the central axis are respectively embedded in the fixing hole 1 and the fixing hole 2 for fixing.

[0007] Both the stator assembly and the rotor assembly are injection-molded one-piece parts, so that the rotor motor of the entire magnetic pump can be completely placed in the pump cavity and fully contact the fluid, effectively enhancing the heat dissipation effect of the motor, and improving the life and working stability of the motor. The rotor assembly is located outside the stator assembly and rotates around the stator assembly, and can withstand higher temperatures and greater loads. The center shaft is passed through the through hole of the rotor assembly, and the two ends of the center shaft are respectively embedded in the fixing hole one and the fixing hole two. The fixed structure can fix the center shaft to the housing and the stator assembly so that all three remain relatively stationary. Moreover, the rotor assembly rotates around the center shaft, so that after the rotor assembly is affected by the magnetic force of the stator assembly, it only needs to drive the impeller to rotate, reducing the center shaft as a rotating component, reducing kinetic energy loss, and thus improving the working efficiency of the magnetic pump. Since the rotor assembly also needs the center shaft to position the rotation. The stability of the central axis can better promote the rotation of the rotor assembly, so the guide vane and the shell are formed in one piece, and the fixing hole 1 in the guide vane will not be offset relative to the shell. The mounting part is fixed to the shell, and the fixing hole 1 on the mounting part will not be offset relative to the shell. Therefore, the central axis is restricted by the fixing holes 1 and 2 in axial, circumferential and radial movement. After the stator assembly, rotor assembly and central axis are assembled, they can be directly installed in the shell for easy installation.

[0008] Furthermore, the outer shell has a cylindrical stepped pump chamber with a diameter increasing from top to bottom, the cylindrical stepped pump chamber includes a first cylindrical chamber, a second cylindrical chamber and a third cylindrical chamber with consistent central axes, the guide vane is formed in the first cylindrical chamber, the first fixing hole is consistent with the central axis of the first cylindrical chamber, the rotor assembly is located in the second cylindrical chamber, and the mounting portion is formed with a mounting disk consistent with the central axis of the second fixing hole, the upper end surface of the mounting disk is sealed against the step surface connecting the second cylindrical chamber and the third cylindrical chamber, and the outer circumferential surface of the mounting disk is sealed against the inner circumferential surface of the third cylindrical chamber.

[0009] Since the outer shell is an integrated plastic body, the central axes of the first cylindrical cavity, the second cylindrical cavity, the third cylindrical cavity and the fixing hole 1 in the guide vane are kept consistent after molding, so that the central axes of the rotor assembly and the central axis can also be kept consistent after installation, thereby improving the rotation efficiency. The upper end face of the mounting disc is sealed against the step surface connecting the second cylindrical cavity and the third cylindrical cavity, which can limit the axial movement of the stator assembly and better enable the fixing hole 2 and the fixing hole 1 to cooperate to support the fixed central axis. The outer circumferential surface of the mounting disc is sealed against the inner circumferential surface of the third cylindrical cavity so that the central axes of the fixing hole 2 and the fixing hole 1 are consistent. It also makes the installation of the impeller, rotor assembly and stator assembly more convenient and convenient for demoulding.

[0010] Furthermore, the guide vane includes a plurality of blades and a cylindrical hub connecting the blades, a fixing hole 1 is located at the lower end of the cylindrical hub, a fixing block 1 protrudes inwardly from the inner side wall of the fixing hole 1, and a shoulder 1 that cooperates with the fixing block 1 is recessed inwardly at the upper part of the central shaft, so as to better fix the central shaft.

[0011] Furthermore, the impeller includes an upper ring plate and a lower ring plate, the inner hole of the upper ring plate is larger than the inner hole of the lower ring plate, the cylindrical hub and the lower part of the blade pass through the inner hole of the upper ring plate until they are close to the lower ring plate, and the cylindrical hub and the blade do not contact the impeller. The above structure shortens the distance between the first fixing hole and the second fixing hole, further shortens the length of the central axis, increases the stability of the central axis, reduces the shaking of the central axis when the rotor assembly rotates around the central axis, improves the efficiency of the whole machine, and reduces the axial length of the pump.

[0012] Furthermore, a concave cavity is formed in the middle of the stator part, which is consistent with the opening of the second fixing hole. The second fixing hole is located at the bottom of the concave cavity. The inner wall of the second fixing hole protrudes inwardly with a fixing block. The lower part of the central shaft is recessed inwardly with a clamping shoulder 2 that cooperates with the fixing block 2. The central shaft is better fixed.

[0013] Furthermore, the middle of the annular inner cavity of the rotor assembly has a cylindrical portion, which extends into the concave cavity, and the middle of the cylindrical portion is a through hole, and a bearing is arranged between the cylindrical portion and the central axis. An annular stopper protrudes inward from the upper end of the cylindrical portion, and a shaft sleeve is arranged on the orifice end face of the concave cavity close to the second fixing hole. The bearing is located between the annular stopper and the shaft sleeve. The rotor assembly rotates around the center under the support and rotation of the bearing. The bearing adopts a graphite bearing, and a spiral flow channel is arranged on the inner wall of the bearing. The fluid can flow from the spiral flow channel to lubricate the contact between the bearing and the central axis. Graphite bearings have good wear resistance and corrosion resistance. While extending the service life, they can also simplify the structure and facilitate assembly.

[0014] Furthermore, a motor base is sealed and fixedly connected below the stator assembly, and the motor base is sealed and fixedly connected to the housing.

[0015] Furthermore, the stator part has a suspended concave cavity in the middle, the upper end of the concave cavity is connected to the stator part, the concave cavity is located in the concave cavity, the motor seat is provided with a concave cavity seat and a fixing portion matching the shape of the concave cavity, the concave cavity seat is embedded in the gap between the concave cavity and the stator, the upper end of the fixing portion abuts against the mounting disc, the cylindrical stepped pump cavity also includes a fourth cylindrical cavity, the outer periphery of the fixing portion is stepped and abuts against the stepped inner periphery formed by the third cylindrical cavity and the fourth cylindrical cavity. A controller for controlling the pump is placed in the fixing portion.

[0016] Furthermore, the stator assembly and the motor base are formed into a whole through plastic injection molding.

[0017] Furthermore, the impeller and the rotor assembly are fixed by a buckle and a slot. A buckle is protruding from the lower end of the impeller, and a slot is arranged at a position of the rotor assembly relative to the buckle, and the buckle is embedded in the slot and fixed.

[0018] Compared with the prior art, the technical effects of the utility model are as follows: the central axis and the outer shell are fixed, and the central axis is supported and stabilized by the cooperation of the stator assembly and the outer shell. After the central axis is better supported and stabilized, it can better support the entire rotor assembly and the impeller, so that the rotor assembly and the impeller can better rotate around the central axis, and the rotation performance is better and more stable; after reducing the rotating part of the central axis, the rotor assembly reduces a certain amount of kinetic energy loss, thereby improving the working efficiency of the magnetic pump; one end of the guide vane with a fixed hole is inserted into the impeller, which can better divert the liquid and shorten the distance for installing the central axis, reduce the length of the central axis, and enhance the stability of the rotor assembly driving the impeller to rotate; the overall structure is convenient for installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the utility model.

[0020] Figure 2 It is a cutaway stereogram of the utility model.

[0021] Figure 3 It is a cutaway stereoscopic diagram of the shell of the utility model.

[0022] Figure 4 It is a stereoscopic diagram of the rotor assembly of the utility model.

[0023] Figure 5 It is a cross-sectional view of the stator assembly at position AA of the utility model.

[0024] Figure 6 It is a schematic diagram of the stator assembly of the utility model.

[0025] Figure 7 It is a cross-sectional view of the motor base of the utility model.

[0026] Figure 8 It is an exploded view of the utility model.

[0027] Figure number marking: 1. Shell; 101. Water inlet; 102. Water outlet; 103. First cylindrical cavity; 104. Second cylindrical cavity; 105. Third cylindrical cavity; 106. Fourth cylindrical cavity; 2. Center axis; 21. Shoulder one; 22. Shoulder two; 3. Impeller; 31. Upper ring plate; 32. Lower ring plate; 4. Rotor assembly; 41. Cylindrical part; 401. Annular inner cavity; 402. Through hole; 5. Stator assembly; 51. Stator part; 511. Concave cavity; 512. Concave cavity part; 52. Mounting part; 521. Fixing hole two; 522. Mounting disc; 53. Fixing block two; 6. Guide vane; 601. Fixing hole one; 61. Blade; 62. Cylindrical hub; 63. Fixing block one; 7. Bearing; 8. Motor seat; 81. Concave cavity seat; 82. Fixing part. DETAILED DESCRIPTION

[0028] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0029] according to Figures 1 to 8 As shown, a fixing structure of a central axis 2 of a magnetic pump is provided, wherein the magnetic pump comprises a housing 1, the housing 1 is provided with a water inlet 101 and a water outlet 102, the housing 1 is provided with an impeller 3, a central axis 2 and an outer rotor motor, wherein the outer rotor motor comprises a stator assembly 5 and a rotor assembly 4, the stator assembly 5 and the rotor assembly 4 are integrally formed by injection molding, and the central axis 2 is located between the stator assembly 5 and the rotor assembly 4.

[0030] The housing 1 is integrally formed of plastic, and the outer shape of the housing 1 is a stepped cylindrical shape. The inside of the housing 1 has a cylindrical stepped pump cavity with a diameter increasing from top to bottom. The cylindrical stepped pump cavity includes a first cylindrical cavity 103, a second cylindrical cavity 104 and a third cylindrical cavity 105 with the same central axis. The guide vane 6 is formed in the first cylindrical cavity 103, and the guide vane 6 and the housing 1 are also integrally formed. The guide vane 6 is provided with a fixing hole 601 opening downward, and the water inlet 101 is provided at the upper end of the housing 1 opposite to the position of the guide vane 6. The guide vane 6 is provided in the cavity between the first cylindrical cavity 103 and the second cylindrical cavity 104, and the water outlet 102 is provided relative to the position of the impeller 3, and the water outlet 102 is provided laterally on the housing 1. The outer shell 1 and the guide vane 6 are made of plastic as an integral body. The first cylindrical cavity 103, the second cylindrical cavity 104, the third cylindrical cavity 105 and the fixing hole 601 in the guide vane 6 are formed to keep the central axis consistent, so that the central axis of the rotor assembly 4 and the central axis 2 can also be kept consistent after installation, thereby improving the rotation efficiency. The integrally molded guide vane 6 also has a more stable structure so that the fixing hole 601 will not be offset relative to the outer shell 1.

[0031] The guide vane 6 includes a plurality of blades 61 and a cylindrical hub 62 connecting the blades 61. The fixing hole 601 is located at the lower end of the cylindrical hub 62. A fixing block 63 protrudes inwardly from the inner side wall of the fixing hole 601. A shoulder 21 matching with the fixing block 63 is recessed inwardly at the upper part of the central shaft 2. The central shaft 2 is better fixed.

[0032] The impeller 3 includes an upper ring plate 31 and a lower ring plate 32, the inner hole of the upper ring plate 31 is larger than the inner hole of the lower ring plate 32, the cylindrical hub 62 and the lower part of the blade 61 pass through the inner hole of the upper ring plate 31 until they are close to the lower ring plate 32, and the cylindrical hub 62 and the blade 61 are not in contact with the impeller 3. The distance between the fixing hole 1 601 and the fixing hole 2 521 is shortened, the length of the central axis 2 is further shortened, the stability of the central axis 2 is increased, the central axis 2 is reduced in shaking when the rotor assembly 4 rotates around the central axis 2, the efficiency of the whole machine is improved, and the axial length of the pump is reduced.

[0033] The rotor assembly 4 has an annular inner cavity 401, and the stator assembly 5 includes a stator portion 51 and a mounting portion 52. The stator portion 51 is in the annular inner cavity 401. The impeller 3 and the rotor assembly 4 are detachably fixed, and the impeller 3 and the rotor assembly 4 are fixed by snapping and snapping. The lower end of the impeller 3 can extend the snap downward, and the rotor assembly 4 is provided with a snap slot relative to the position of the snap. The snap and the snap slot can be clamped to fix the impeller 3 and the rotor assembly 4. A through hole 402 consistent with the central axis of the annular inner cavity 401 is provided in the middle of the rotor assembly 4. The middle part of the annular inner cavity 401 of the rotor assembly 4 has a cylindrical portion 41, and the cylindrical portion 41 extends into the concave cavity 511. The middle of the cylindrical portion 41 is a through hole 402, and a bearing 7 is provided between the cylindrical portion 41 and the central axis 2. An annular stopper protrudes inward from the upper end of the cylindrical portion 41, and a sleeve is provided on the end surface of the cavity 511 near the opening of the second fixing hole 521. The bearing 7 is located between the annular stopper and the sleeve. The bearing 7 is a graphite bearing 7. A spiral flow channel is provided on the inner wall of the bearing 7. Fluid can flow from the spiral flow channel to lubricate the contact between the bearing 7 and the central shaft 2. The graphite bearing 7 has good wear resistance and corrosion resistance, and can simplify the structure and facilitate assembly while extending the service life.

[0034] The stator assembly 5 includes a stator portion 51 and a mounting portion 52. The stator portion 51 is located in the annular inner cavity 401. The mounting portion 52 is provided with a second fixing hole 521 opening upward. The mounting portion 52 is formed with a mounting disc 522 that is consistent with the central axis of the second fixing hole 521. The upper end surface of the mounting disc 522 is sealed against the step surface connecting the second cylindrical cavity 104 and the third cylindrical cavity 105. The outer peripheral surface of the mounting disc 522 is sealed against the inner peripheral surface of the third cylindrical cavity 105. The rotor assembly 4 is located in the second cylindrical cavity 104, and the stator portion 51 is located in the annular inner cavity 401 of the rotor assembly 4. A concave cavity 511 that is consistent with the opening of the second fixing hole 521 is formed in the middle of the stator portion 51. The second fixing hole 521 is located at the bottom of the concave cavity 511. The inner side wall of the second fixing hole 521 protrudes inwardly with a fixing block 53. The lower part of the central shaft 2 is recessed inwardly with a clamping shoulder 22 that cooperates with the fixing block 53.

[0035] The motor base 8 is sealed and fixedly connected below the stator assembly 5, and the motor base 8 is sealed and fixedly connected to the housing 1. A suspended concave cavity 512 is provided in the middle of the stator portion 51, and the upper end of the concave cavity 512 is connected to the stator portion 51, and the concave cavity 511 is located in the concave cavity 512. The motor base 8 is provided with a concave cavity seat 81 and a fixed portion 82 that match the shape of the concave cavity 512, and the concave cavity seat 81 is embedded in the gap between the concave cavity 512 and the stator portion 51, and the upper end of the fixed portion 82 abuts against the mounting disc 522. The cylindrical stepped pump cavity also includes a fourth cylindrical cavity 106, and the outer periphery of the fixed portion 82 is stepped and abuts against the stepped inner periphery formed by the third cylindrical cavity 105 and the fourth cylindrical cavity 106. A controller for controlling the pump is placed in the fixed portion 82. The stator assembly 5 and the motor base 8 can also be formed into a whole by plastic injection molding.

[0036] Wherein the stator assembly 5 and the rotor assembly 4 are both injection molded integral parts, so that the rotor motor of the entire magnetic pump can be completely placed in the pump cavity and fully contact with the fluid, effectively enhancing the heat dissipation effect of the motor, and improving the life and working stability of the motor. The rotor assembly 4 is located outside the stator assembly 5 and rotates around the stator assembly 5, and can withstand higher temperatures and greater loads. The central axis 2 is passed through the through hole 402 of the rotor assembly 4, and the two ends of the central axis 2 are respectively embedded in the fixing hole 1 601 and the fixing hole 2 521 to fix the structure, which can keep the central axis 2 and the housing 1 and the stator assembly 5 in a relatively static state. At this time, the rotor assembly 4 rotates around the central axis 2, so that the rotor assembly 4 only needs to drive the impeller 3 to rotate after being subjected to the magnetic force of the stator assembly 5, reducing the central axis 2, the rotating component, reducing the kinetic energy loss, and thus improving the working efficiency of the magnetic pump. Since the rotor assembly 4 needs the central axis 2 to position the rotation. The stability of the central shaft 2 can better promote the rotation of the rotor assembly 4, so the guide vane 6 and the shell 1 are injection molded as one piece, and the fixing hole 1 601 in the guide vane 6 will not be offset relative to the shell 1. The mounting portion 52 is fixed to the shell 1, and the fixing hole 1 601 on the mounting portion 52 will not be offset relative to the shell 1. Therefore, the central shaft 2 is restricted in axial, circumferential and radial movement by the fixing hole 1 601 and the fixing hole 2 521 as well as the fixing block 1 63 and the fixing block 2 53. After the stator assembly 5, the rotor assembly 4 and the central shaft 2 are transferred, they can be directly installed in the shell 1 for easy installation.

[0037] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope defined by the claims of the present invention.

Claims

1. A structure for fixing the central axis of a magnetic pump, the magnetic pump comprising a housing (1) having a water inlet (101) and a water outlet (102), the housing (1) being provided with a central axis (2), an impeller (3), an injection-molded rotor assembly (4) and an injection-molded stator assembly (5), the rotor assembly (4) having an annular inner cavity (401), the stator assembly (5) comprising a stator portion (51) and a mounting portion (52), the stator portion (51) being located in the annular inner cavity (401), the impeller (3) and the rotor assembly (4) being detachably fixed, characterized in that: A guide vane (6) is integrally formed in the housing (1) and is located opposite to the water inlet (101); the guide vane (6) is provided with a first fixing hole (601) opening downward; a through hole (402) which is consistent with the central axis of the annular inner cavity (401) is provided in the middle of the rotor assembly (4); a second fixing hole (521) which is opened upward is provided on the mounting portion (52); the central axis (2) passes through the through hole (402); and two ends of the central axis (2) are respectively embedded in the first fixing hole (601) and the second fixing hole (521) for fixation.

2. The fixing structure of the central axis of a magnetic pump according to claim 1, characterized in that: The housing (1) has a cylindrical stepped pump cavity with a diameter increasing from top to bottom. The cylindrical stepped pump cavity includes a first cylindrical cavity (103), a second cylindrical cavity (104) and a third cylindrical cavity (105) with the same central axis. The guide vane (6) is formed in the first cylindrical cavity (103). The first fixing hole (601) is consistent with the central axis of the first cylindrical cavity (103). The rotor assembly (4) is located in the second cylindrical cavity (104). The mounting portion (52) is formed with a mounting disc (522) consistent with the central axis of the second fixing hole (521). The upper end surface of the mounting disc (522) is sealed against the step surface connecting the second cylindrical cavity (104) and the third cylindrical cavity (105), and the outer peripheral surface of the mounting disc (522) is sealed against the inner peripheral surface of the third cylindrical cavity (105).

3. The fixing structure of the central axis of a magnetic pump according to claim 2, characterized in that: The guide vane (6) comprises a plurality of blades (61) and a cylindrical hub (62) for connecting the blades (61); a fixing hole (601) is located at the lower end of the cylindrical hub (62); a fixing block (63) protrudes inwardly from the inner side wall of the fixing hole (601); and a clamping shoulder (21) matching the fixing block (63) is recessed inwardly on the upper part of the central shaft (2).

4. The fixing structure of the central axis of a magnetic pump according to claim 3, characterized in that: The impeller (3) comprises an upper ring plate (31) and a lower ring plate (32); the inner hole of the upper ring plate (31) is larger than the inner hole of the lower ring plate (32); the cylindrical hub (62) and the lower part of the blades (61) pass through the inner hole of the upper ring plate (31) until they are close to the lower ring plate (32); and the cylindrical hub (62) and the blades (61) do not contact the impeller (3).

5. The fixing structure of the central axis of a magnetic pump according to claim 2, characterized in that: A concave cavity (511) is formed in the middle of the stator part (51) and is consistent with the opening of the second fixing hole (521). The second fixing hole (521) is located at the bottom of the concave cavity (511). A second fixing block (53) protrudes inwardly from the inner side wall of the second fixing hole (521). A second clamping shoulder (22) that cooperates with the second fixing block (53) is recessed inwardly at the lower part of the central axis (2).

6. The fixing structure of the central axis of a magnetic pump according to claim 5, characterized in that: The middle part of the annular inner cavity (401) of the rotor assembly (4) has a cylindrical part (41), the cylindrical part (41) extends into the concave cavity (511), the middle of the cylindrical part (41) is a through hole (402), and a bearing (7) is arranged between the cylindrical part (41) and the central axis (2).

7. The fixing structure of the central axis of a magnetic pump according to claim 6, characterized in that: A motor base (8) is sealed and fixedly connected below the stator assembly (5), and the motor base (8) is sealed and fixedly connected to the housing (1).

8. The fixing structure of the central axis of a magnetic pump according to claim 7, characterized in that: The stator part (51) has a suspended concave cavity part (512) in the middle, the upper end of the concave cavity part (512) is connected to the stator part (51), the concave cavity (511) is located in the concave cavity part (512), the motor base (8) is provided with a concave cavity seat (81) and a fixing part (82) matching the shape of the concave cavity part (512), the concave cavity seat (81) is embedded in the gap between the concave cavity part (512) and the stator part (51), the upper end of the fixing part (82) is in contact with the mounting disc (522), the cylindrical stepped pump cavity also includes a fourth cylindrical cavity (106), the outer periphery of the fixing part (82) is stepped and is in contact with the stepped inner periphery formed by the third cylindrical cavity (105) and the fourth cylindrical cavity (106).

9. A fixing structure for the central axis of a magnetic pump according to claim 6 or 7, characterized in that: The stator assembly (5) and the motor base (8) are formed into a whole by plastic injection molding.

10. The fixing structure of the central axis of a magnetic pump according to claim 1, characterized in that: The impeller (3) and the rotor assembly (4) are fixed by means of a buckle and a slot.

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