CN222848364U - Outer rotor fan - Google Patents

Abstract

The utility model relates to an outer rotor fan. The outer rotor fan comprises a stator plastic sealing component and a rotor plastic sealing component. The plastic sealing body, the winding stator and the shaft core are integrally injection-molded to form the stator plastic sealing component, and the fan blade rotor and the magnetic ring are integrally injection-molded to form the rotor plastic sealing component, so as to improve the integration degree of the outer rotor fan, reduce the production process, reduce the assembly difficulty, improve the assembly efficiency, and improve the installation accuracy. At the same time, because the fan blade rotor and the magnetic ring are integrally injection-molded to form the rotor plastic sealing component, the wind wheel and the outer rotor are an integrated component, which reduces the dynamic imbalance and further reduces the noise generated during the operation of the fan; and by arranging the bearing sleeve on the exposed end of the shaft core, and arranging the exposed end of the shaft core outside the plastic sealing body, the number of bearings can be reduced, and assembly is convenient.

Description

Outer rotor fan

Technical Field

The utility model relates to a fan, in particular to an outer rotor fan.

Background

The air supply fan of the gas water heater generally comprises a volute and a driving motor, wherein the driving motor is arranged on the outer wall of the volute, an air inlet and an air outlet are formed in the volute, and a centrifugal wind wheel is arranged in the volute and is respectively communicated with the air inlet and the air outlet. The driving motor comprises a stator, a rotor and an output shaft, wherein the output shaft is fixed on the rotor, the stator is provided with two bearings, and the output shaft is sleeved with the bearings, so that the rotor is rotationally connected to the stator. One end of the output shaft extends into the volute and is detachably connected with the centrifugal wind wheel.

Because the rotor of centrifugal wind wheel and driving motor belongs to different rotation devices, after the air supply fan is assembled, centrifugal wind wheel has dynamic unbalance, rotor also has dynamic unbalance, and the dynamic unbalance of two rotation devices is superimposed, easily causes the fan to vibrate and produce noise, and the part is more, has increased the equipment process.

Disclosure of utility model

The utility model provides an outer rotor fan, which can reduce noise generated by vibration of the fan and improve assembly efficiency.

The first technical problem is solved by the following technical scheme:

The outer rotor fan comprises a stator plastic package assembly and a rotor plastic package assembly, wherein the stator plastic package assembly comprises an integrally injection molded plastic package body, a winding stator and a shaft core, the winding stator and the shaft core are arranged on the plastic package body, the winding stator is uniformly arranged on the shaft core in a surrounding mode, the rotor plastic package assembly comprises an integrally injection molded fan blade rotor and a magnetic ring, the fan blade rotor is only provided with a bearing, at least half of the shaft core is in the plastic package body, the shaft core is provided with a shaft core exposed end which is externally leaked to the plastic package body, the bearing is sleeved on the shaft core exposed end, the bearing and the winding stator are arranged in a staggered mode in the axial direction of the shaft core, and the magnetic ring is arranged on the periphery of the winding stator in a surrounding mode.

Compared with the prior art, the outer rotor fan has the advantages that the plastic package body, the winding stator and the shaft core are integrally injection-molded to form the stator plastic package assembly, the fan blade rotor and the magnetic ring are integrally injection-molded to form the rotor plastic package assembly, the assembly difficulty is reduced, the assembly efficiency is improved, meanwhile, the fan blade rotor and the magnetic ring are integrally injection-molded to form the rotor plastic package assembly, the wind wheel and the outer rotor are made to be integrated components, split type design in the existing scheme is not needed, the phenomenon of unbalanced superposition of the wind wheel and the outer rotor after installation in the existing scheme is avoided, the unbalanced quantity of the movement is reduced, and noise generated in the working process of the fan is further reduced. Meanwhile, at least half of the shaft core is in plastic package on the plastic package body, so that the shaft core has good supporting stability, the bearing is arranged on the fan blade rotor under the condition of keeping the whole size, the bearing and the winding stator are arranged in a staggered mode, a larger space is reserved, a larger-size bearing can be used, the reliability of the larger-size bearing is high, the number of the bearings can be reduced, and the assembly efficiency is further improved.

In one embodiment, the winding stator comprises an iron core and a coil wound on the iron core, and the magnetic force center line of the iron core and the magnetic force center line of the magnetic ring are staggered in the axial direction of the shaft core.

The outer rotor fan has the beneficial effects that the magnetic force center line of the iron core and the magnetic force center line of the magnetic ring are staggered in the axial direction of the shaft core, the generated magnetic force acts on the fan blade rotor, the gravity action of the fan blade rotor is reduced, the pre-pressure can be provided for the bearing, the ball bearing inner ring and the ball bearing outer ring are arranged in a flush manner in the axial direction of the shaft core, the friction force generated in the bearing rotating process is reduced, stable rotation is realized, and the noise generated in the outer rotor fan working process is reduced.

In one embodiment, the distance between the magnetic force center line of the iron core and the magnetic force center line of the magnetic ring, which is staggered in the axial direction of the shaft core, is L, and L is more than or equal to 1mm and less than or equal to 5mm.

In one embodiment, the bearing is an interference fit with the exposed end of the shaft core.

The outer rotor fan has the beneficial effects that the bearing is in interference fit with the exposed end of the shaft core, so that the bearing is prevented from being separated from the exposed end of the shaft core when rotating at a high speed, and the connection relationship between the bearing and the exposed end of the shaft core is more reliable.

In one embodiment, the fan blade rotor is formed with a bearing chamber disposed around the exposed end of the shaft core, and a bearing is disposed in the bearing chamber.

In one embodiment, the bearings are ball bearings.

In one embodiment, the outer circumferential surface of the shaft core is provided with an annular groove which is recessed inwards, and the plastic package body is provided with an embedded part meshed with the annular groove.

The outer rotor fan has the beneficial effects that the annular groove is formed in the peripheral surface of the shaft core, and the embedded part meshed with the annular groove is formed in the plastic package body, so that the axial displacement of the plastic package body along the shaft core during rotation of the plastic package body is avoided, and the connection relationship between the plastic package body and the annular groove is more reliable.

In one embodiment, the plastic package comprises a spiral case, wherein the spiral case is provided with a ventilating duct and a mounting port, the mounting port is communicated with the ventilating duct, the plastic package body comprises a mounting plate and a plastic package main body, the mounting plate is detachably mounted on the mounting port, the winding stator is arranged on the plastic package main body, and the plastic package main body and the rotor plastic package assembly are located in the ventilating duct.

The outer rotor fan has the beneficial effects that the mounting plate is detachably mounted at the mounting opening of the volute to form a cavity with a ventilation pipeline in a surrounding manner, the winding stator, the plastic package main body and the rotor plastic package component are arranged in the ventilation pipeline, a motor mounting space is not required to be additionally arranged outside the volute, the axial size of the outer rotor motor in the axial direction of the shaft core is reduced, and the whole size of the outer rotor motor is further reduced.

In one embodiment, the volute is provided with an air inlet communicated with the ventilating duct, the fan blade rotor comprises a plastic package rotor, a plastic package wind wheel and a plastic package bridging section, the plastic package rotor and the plastic package bridging section are integrally injection molded, the plastic package rotor, the plastic package bridging section and the plastic package wind wheel are enclosed to form an air inlet cavity with a concave direction of the air inlet, and the magnetic ring is arranged on the plastic package rotor.

In one embodiment, the magnetic ring comprises at least one group of N-pole magnetic steel and S-pole magnetic steel, and the N-pole magnetic steel and the S-pole magnetic steel are arranged in a staggered manner along the circumferential direction. The integration level can be improved, and the assembly efficiency is further improved.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a cross-sectional view of an outer rotor fan provided by the utility model;

FIG. 2 is a cross-sectional view of a stator plastic package assembly in an outer rotor fan provided by the utility model;

FIG. 3 is a cross-sectional view of a rotor plastic package assembly in an outer rotor fan provided by the utility model;

FIG. 4 is a schematic diagram of a magnetic force center line of a magnetic ring and a magnetic force center line of an iron core in an outer rotor fan provided by the utility model;

FIG. 5 is a cross-sectional view of a plastic encapsulated rotor in an outer rotor fan provided by the utility model, including a first inner peripheral wall;

FIG. 6 is a cross-sectional view of the outer rotor blower provided by the present utility model with a volute having a sleeve;

FIG. 7 is a top view of the outer rotor fan provided by the utility model with a volute having a sleeve;

Reference numerals illustrate:

1. The stator plastic package assembly comprises a stator plastic package assembly, 11, a plastic package body, 111, an embedded part, 112, a mounting plate, 113, a plastic package main body, 114, a boss, 12, a winding stator, 121, an iron core, 122, a coil, 13, a shaft core, 131, a shaft core exposed end, 132 and a ring groove;

2. The rotor plastic package assembly comprises a rotor plastic package assembly, a fan blade rotor, a rotor 211, a bearing chamber, a rotor 212, a plastic package rotor 2121, a mounting cavity, a 2122, a first inner peripheral wall, a 2123, a second inner peripheral wall, a 213, a plastic package wind wheel, 214, a plastic package bridging section, 215, an air inlet cavity, 22 and a magnetic ring;

3. A bearing;

4. Volute casing 411, shaft sleeve.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present application, it should be understood that the directions or positional relationships indicated by the terms "inner", "outer", "upper", "lower", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present application, unless explicitly stated and limited otherwise, the terms "mounted" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediate medium, or communicating between the two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

Referring to fig. 1 to 7, fig. 1 shows a cross-sectional view of an outer rotor fan according to an embodiment of the present application, fig. 2 shows a cross-sectional view of a stator plastic package assembly in an outer rotor fan according to an embodiment of the present application, fig. 3 shows a cross-sectional view of a rotor plastic package assembly in an outer rotor fan according to an embodiment of the present application, fig. 4 shows a schematic diagram of a magnetic force center line of a magnetic ring and a magnetic force center line of an iron core in an outer rotor fan according to an embodiment of the present application, fig. 5 shows a cross-sectional view of a plastic package rotor in an outer rotor fan according to an embodiment of the present application including a first inner circumferential wall, fig. 6 shows a cross-sectional view of a volute casing in an outer rotor fan according to an embodiment of the present application having a sleeve, and fig. 7 shows a top view of a volute casing in an outer rotor fan according to an embodiment of the present application.

The application provides an outer rotor fan, which is shown in fig. 1 to 3, and comprises a stator plastic package assembly 1 and a rotor plastic package assembly 2, wherein the stator plastic package assembly 1 comprises an integrally injection molded plastic package body 11, a winding stator 12 and a shaft core 13, the winding stator 12 and the shaft core 13 are arranged on the plastic package body 11, the winding stator 12 is uniformly surrounded on the shaft core 13 along the circumferential direction, the rotor plastic package assembly 2 comprises an integrally injection molded fan blade rotor 21 and a magnetic ring 22, the fan blade rotor 21 is only provided with a bearing 3, at least half of the shaft core 13 is molded in the plastic package body 11, the shaft core 13 is provided with a shaft core exposed end 131 which is leaked outside the plastic package body 11, the bearing 3 is sleeved on the shaft core exposed end 131, the bearing 3 is arranged in a dislocation manner with the winding stator 12 along the axial direction of the shaft core 13, and the magnetic ring 22 is surrounded on the periphery of the winding stator 12.

The stator plastic package assembly 1 is formed by integrally molding the plastic package body 11, the winding stator 12 and the shaft core 13, the rotor plastic package assembly 2 is formed by integrally molding the fan blade rotor 21 and the magnetic ring 22, the production process can be reduced, the assembly difficulty is reduced, the assembly efficiency is improved, the installation precision is improved, meanwhile, the rotor plastic package assembly 2 is formed by integrally molding the fan blade rotor 21 and the magnetic ring 22, the wind wheel and the outer rotor are integrated, split type design is not needed in the prior art, the phenomenon of dynamic unbalance superposition after the wind wheel and the outer rotor are installed is avoided, the dynamic unbalance is reduced, noise generated in the working process of the fan is reduced, the bearing 3 is sleeved at the exposed end 131 of the shaft core, and the exposed end 131 of the shaft core is arranged outside the plastic package body 11, so that the integration degree of the outer rotor fan is improved.

It will be appreciated that in the prior art, the shaft core 13 is arranged on the rotor, the bearing 3 is arranged on the stator, and the bearing 3 can only be used with smaller dimensions, and two bearings 3 are required for overall stability. According to the application, the shaft system is designed differently from the shaft system in the prior art, at least half of the shaft core 13 is molded on the molded body 11, so that the shaft core 13 has good supporting stability, the bearing 3 is arranged on the fan blade rotor 21, the bearing 3 is arranged in a dislocation manner with the winding stator 12 in the axial direction of the shaft core 13, the influence of the winding stator 12 on the installation of the shaft core 13 can be effectively avoided, a larger space is further provided, a larger-size bearing 3 can be used under the condition that the overall size is basically unchanged, the reliability and the balance of the larger-size bearing 3 are high, the number of the bearings 3 can be reduced, and the assembly efficiency is further improved.

As shown in fig. 1 and 3, the winding stator 12 includes an iron core 121 and a coil 122 wound around the iron core 121, and the magnetic force center line of the iron core 121 and the magnetic force center line of the magnet ring 22 are offset from each other in the axial direction of the shaft core 13.

By arranging the magnetic force center line of the iron core 121 and the magnetic force center line of the magnetic ring 22 in the axial direction of the shaft core 13 in a staggered manner, the generated magnetic force acts on the bearing 3 to provide pre-pressure for the bearing 3, so that the ball bearing inner ring and the ball bearing outer ring are arranged in the axial direction of the shaft core 13 in a flush manner, the friction force generated in the rotation process of the bearing 3 is reduced, stable rotation is realized, and the noise generated in the working process of the outer rotor fan is reduced.

As one of the embodiments, the bearing 3 is a ball bearing.

Specifically, as shown in fig. 1 and 4, the magnetic force center line of the iron core 121 and the magnetic force center line of the magnet ring 22 are offset by a distance L in the axial direction of the shaft core 13.

It may be noted that the range of the distance L is not specifically limited, and the distance L may be determined according to the actual requirement of the outer rotor fan.

As one embodiment, 1 mm.ltoreq.L.ltoreq.5 mm.

As shown in fig. 1, 2, and 4 to 6, the bearing 3 is interference fit with the shaft core exposed end 131. The arrangement prevents the bearing 3 from being separated from the exposed end 131 of the shaft core when rotating at high speed, so that the connection relationship between the bearing 3 and the shaft core is more reliable. In other embodiments, the bearing 3 may also be mounted on the exposed end 131 of the shaft core by a snap spring.

As shown in fig. 1, 4 to 6, the vane rotor 21 is formed with a bearing chamber 211 provided around the shaft core exposed end 131, and the bearing 3 is provided in the bearing chamber 211. So set up, because the bearing 3 is placed in the bearing room 211, be in plastic envelope rotor 212 inside, the bearing 3 of optional size great is convenient for make the relation of connection more reliable after bearing 3 installs to the noise reduction.

Further, the ball bearing comprises a ball bearing outer ring and a ball bearing inner ring, the ball bearing outer ring is embedded and fixed on the inner wall of the bearing chamber 211, the ball bearing inner ring is sleeved on the periphery of the exposed end 131 of the shaft core, the plastic package 11 is provided with a boss 114, the boss 114 is sleeved on the periphery of the exposed end 131 of the shaft core, and the boss 114 is used for abutting against the ball bearing inner ring.

So set up, through fixing the outer lane gomphosis at the bearing room 211 inner wall to locate the periphery of axle core exposed end 131 with the inner race cover, be convenient for in the radial spacing bearing 3 of axle core 13, through being equipped with the boss 114 of butt in ball bearing inner race in plastic envelope body 11 department again, be convenient for at the spacing bearing 3 of axle core 13 axial, make bearing 3, axle core 13, plastic envelope body 11, plastic envelope rotor 212 more reliable in the relation of connection after the assembly.

As shown in fig. 1, 2, and 4 to 6, the outer circumferential surface of the shaft core 13 is provided with an inwardly recessed ring groove 132, and the plastic package 11 has an embedded portion 111 engaged with the ring groove 132. By the arrangement, axial displacement along the shaft core 13 during rotation of the plastic package body 11 is avoided, and the connection relationship between the plastic package body and the shaft core is more reliable.

As shown in fig. 1 and fig. 4 to fig. 7, the outer rotor fan further comprises a volute 4, the volute 4 is provided with a ventilation pipeline and a mounting opening, the mounting opening is communicated with the ventilation pipeline, the plastic package body 11 comprises a mounting plate 112 and a plastic package main body 113, the mounting plate 112 is detachably mounted at the mounting opening, the winding stator 12 is arranged on the plastic package main body 113, and the plastic package main body 113 and the rotor plastic package assembly 2 are located in the ventilation pipeline.

By means of the arrangement, the mounting plate 112 is detachably mounted at the mounting opening of the volute 4, the winding stator 12, the plastic package main body 113 and the rotor plastic package assembly 2 extend into the ventilating duct, a mounting space for a driving motor is not required to be additionally arranged outside the volute 4, the axial size of the whole outer rotor fan in the shaft core 13 is reduced, and the whole size of the outer rotor fan is further reduced.

In one embodiment, the plastic package material of the stator plastic package assembly 1 is a thermosetting material BMC, so that the heat dissipation of the iron core 121 and the coil 122 in the plastic package main body 113 is facilitated, meanwhile, the air is isolated from aging and corrosion, and meanwhile, the plastic package main body 113 is positioned in the ventilation pipeline, so that the heat dissipation effect of the iron core 121 and the coil 122 can be further enhanced, and the service life is further prolonged.

The structure of the scroll case 4 is not particularly limited.

As one embodiment, as shown in fig. 1, 4 and 5, the top wall of the volute 4 is provided with an air inlet communicated with the ventilating duct, and the air inlet can be square or round.

As another embodiment, as shown in fig. 6 and 7, a shaft sleeve 411 is disposed at the air inlet of the volute 4, and the shaft sleeve 411 is used for being sleeved on the outer periphery of the exposed end 131 of the shaft core, and the shaft core 13 is fixed with the plastic package main body 113 and the plastic package rotor 212, so that axial or radial displacement of the shaft core 13 in the working process can be limited, and the stability of the shaft core 13 is further improved.

In one embodiment, as shown in fig. 1 and 3, the fan blade rotor 21 includes an integrally injection molded plastic package rotor 212, a plastic package wind wheel 213, and a plastic package bridging section 214 between the plastic package rotor 212 and the plastic package wind wheel 213, wherein an air inlet cavity 215 recessed in a direction away from the air inlet is formed by enclosing the plastic package rotor 212, the plastic package bridging section 214 and the plastic package wind wheel 213, and the magnetic ring 22 is disposed on the plastic package rotor 212.

It should be noted that, as shown in fig. 3, the plastic-sealed rotor 212 is provided with a mounting cavity 2121, the mounting cavity 2121 is a cylindrical concave cavity, the plastic-sealed main body 113 is a cylindrical boss, and the plastic-sealed main body 113 is placed in the mounting cavity 2121 during mounting.

In one embodiment, the magnetic ring 22 is in a ring shape, and the magnetic ring 22 includes at least one set of N-pole magnetic steel and S-pole magnetic steel, where the N-pole magnetic steel and the S-pole magnetic steel are staggered along the circumferential direction. Specifically, at least one N pole and at least one S pole are subjected to plastic packaging to obtain a magnetic ring 22 with a plastic protection layer outside, and the magnetic ring 22 is placed into an injection mold for injection molding to form the fan blade rotor 21.

In one embodiment, as shown in fig. 1 and 5, the inner end of the plastic-sealed rotor 212 near the shaft core 13 is provided with a first inner circumferential wall 2122 extending along the shaft core 13 axially near the plastic-sealed main body 113, and the bearing chamber 211 is formed on the first inner circumferential wall 2122 of the plastic-sealed rotor 212. In other embodiments, as shown in fig. 1 and 3, the inner end of the plastic-sealed rotor 212 near the shaft core 13 is provided with a second inner circumferential wall 2123 extending away from the plastic-sealed main body 113 along the shaft core 13 axial direction, and the bearing chamber 211 is formed on the second inner circumferential wall 2123 of the plastic-sealed rotor 212. So set up, form bearing room 211 on plastic envelope rotor 212's first inner peripheral wall 2122 or second inner peripheral wall 2123, because plastic envelope rotor 212 is located the space of plastic envelope main part 113 top is great, the space of the bearing room 211 that forms is also great, is convenient for place the bearing 3 of great size to improve the stationarity of plastic envelope rotor 212 rotation in-process, noise reduction.

The plastic package main body 113 is wrapped around the outer periphery of the shaft core 13, and the inner wall of the plastic package main body 113 is attached to the outer wall of the shaft core 13.

So set up, through the main part laminating setting of inner wall with plastic envelope main part 113 and axle core 13, reduce the volume of the inside cavity of plastic envelope main part 113, improve the structural strength of plastic envelope main part 113, and then improve the life-span of plastic envelope main part 113 to make the structure of external rotor fan more reliable, make axle core 13 have more stable holding power.

During installation, the stator plastic package assembly 1 and the rotor plastic package assembly 2 obtained through injection molding are taken out, the ball bearings are pressed into the bearing chambers 211, then the ball bearings are sleeved at the exposed ends 131 of the shaft cores, finally, the fixing of the spiral case 4 and the plastic package body 11 is finished, for example, the spiral case 4 and the plastic package body 11 are provided with buckling structures, buckling is finished during installation, or the spiral case 4 and the plastic package body 11 are connected and fixed by using threaded connection structures, for example, the outer edge parts of the spiral case 4 and the plastic package body 11 are provided with connecting holes, for example, threaded connecting holes, and fastening is finished by using bolts during installation. In addition, if the shaft sleeve 411 is disposed at the position of the scroll case 4, the shaft sleeve 411 needs to be sleeved into the exposed end 131 of the shaft core before the scroll case 4 and the plastic package 11 are assembled.

In the specific content of the above embodiment, any combination of the technical features may be performed without contradiction, and for brevity of description, all possible combinations of the technical features are not described, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing detailed description of the embodiments presents only a few embodiments of the present utility model, which are described in some detail and are not intended to limit the scope of the present utility model. 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 utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims (10)

1. The outer rotor fan is characterized by comprising a stator plastic package assembly (1) and a rotor plastic package assembly (2), wherein the stator plastic package assembly (1) comprises a plastic package body (11), a winding stator (12) and a shaft core (13) which are integrally injection molded, the winding stator (12) and the shaft core (13) are arranged on the plastic package body (11), the winding stator (12) is uniformly arranged on the shaft core (13) in a surrounding manner along the circumferential direction, the rotor plastic package assembly (2) comprises a fan blade rotor (21) and a magnetic ring (22) which are integrally injection molded, the fan blade rotor (21) is only provided with a bearing (3), at least one half of the shaft core (13) is plastic-packaged in the plastic package body (11), the shaft core (13) is provided with a shaft core exposed end (131) which is externally leaked to the plastic package body (11), the bearing (3) is sleeved on the shaft core exposed end (131), the bearing (3) is arranged on the periphery of the winding stator (12) in a misplacement manner along the axial direction of the shaft core (13), and the winding stator (12) is arranged on the periphery of the winding stator (12).

2. The outer rotor fan according to claim 1, wherein the winding stator (12) comprises an iron core (121) and a coil (122) wound around the iron core (121), and a magnetic force center line of the iron core (121) and a magnetic force center line of the magnetic ring (22) are arranged in a staggered manner in an axial direction of the shaft core (13).

3. The outer rotor fan according to claim 2, wherein a distance between a magnetic force center line of the iron core (121) and a magnetic force center line of the magnetic ring (22) which is staggered in an axial direction of the shaft core (13) is L, and L is more than or equal to 1mm and less than or equal to 5mm.

4. The external rotor fan according to claim 1, characterized in that the bearing (3) is in an interference fit with the exposed end (131) of the shaft core.

5. The external rotor fan according to claim 1, characterized in that the fan blade rotor (21) is formed with a bearing chamber (211) provided around the shaft core exposed end (131), and the bearing (3) is provided in the bearing chamber (211).

6. The external rotor fan according to claim 1, characterized in that the bearing (3) is a ball bearing (3).

7. The outer rotor fan according to claim 1, wherein an annular groove (132) recessed inward is provided on an outer peripheral surface of the shaft core (13), and the plastic package body (11) has an embedded portion (111) engaged with the annular groove (132).

8. The outer rotor fan according to claim 1, further comprising a volute (4), wherein the volute (4) is provided with a ventilating duct and a mounting opening, the mounting opening is communicated with the ventilating duct, the plastic package body (11) comprises a mounting plate (112) and a plastic package main body (113), the mounting plate (112) is detachably mounted on the mounting opening, the winding stator (12) is arranged on the plastic package main body (113), and the plastic package main body (113) and the rotor plastic package assembly (2) are located in the ventilating duct.

9. The external rotor fan according to claim 8, wherein the volute (4) is provided with an air inlet communicated with the ventilation pipeline, the fan blade rotor (21) comprises a plastic package rotor (212), a plastic package wind wheel (213) and a plastic package bridging section (214) positioned between the plastic package rotor (212) and the plastic package wind wheel (213), an air inlet cavity (215) recessed towards a direction far away from the air inlet is formed by enclosing the plastic package rotor (212), the plastic package bridging section (214) and the plastic package wind wheel (213), and the magnetic ring (22) is arranged on the plastic package rotor (212).

10. The outer rotor fan according to any one of claims 1-9, wherein the magnetic ring (22) comprises at least one set of N-pole magnetic steel and S-pole magnetic steel, the N-pole magnetic steel and the S-pole magnetic steel being arranged in a circumferential staggered manner.