Outer rotor fan

Abstract

The utility model relates to an outer rotor fan. The outer rotor fan comprises a stator plastic package assembly and a rotor plastic package assembly. The plastic package body, the winding stator and the shaft core are subjected to integral injection molding to form the stator plastic package assembly, and the fan blade rotor and the magnetic ring are subjected to integral injection molding to form the rotor plastic package assembly, so that the production procedures can be reduced, the assembly difficulty can be reduced, and the assembly efficiency can be improved; according to the technical scheme, the wind wheel and the outer rotor are integrated components, split design in the prior art is not needed, the phenomenon of dynamic unbalance superposition after the wind wheel and the rotor are installed in the prior art is avoided, the dynamic unbalance amount is reduced, noise generated in the working process of the fan is reduced, the integration degree is improved, and assembling is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of fans, in particular to an outer rotor fan. Background Art

[0002] The air supply fan of a gas water heater generally includes a volute and a drive motor, the drive motor is mounted on the outer wall of the volute, and the volute is provided with an air inlet and an air outlet. The drive motor includes a stator, a rotor and an output shaft, wherein one end of the output shaft extends into the volute and is detachably connected to a centrifugal fan wheel.

[0003] Since the centrifugal fan wheel and the rotor of the driving motor belong to different rotating components, after being assembled into an air supply fan, the centrifugal fan wheel has dynamic imbalance and the rotor also has dynamic imbalance. The superposition of the dynamic imbalance of the two rotating components can easily cause the fan to vibrate and generate noise. Utility Model Content

[0004] The utility model provides an outer rotor fan, which can reduce the noise generated by the vibration of the fan.

[0005] The above technical problems are solved by the following technical solutions:

[0006] An external rotor fan comprises a stator plastic packaging component and a rotor plastic packaging component, the stator plastic packaging component comprises an integrally injected plastic packaging body, a winding stator and an axis core, the winding stator and the axis core are arranged on the plastic packaging body, and the winding stator is uniformly arranged around the axis core along the circumferential direction; the rotor plastic packaging component comprises an integrally injected fan blade rotor and a magnetic ring, the fan blade rotor is rotatably connected to the axis core, and the magnetic ring is arranged around the periphery of the winding stator.

[0007] Compared with the background technology, the outer rotor fan described in the utility model has the following beneficial effects: the plastic sealing body, the winding stator and the shaft core are integrally injection-molded to form a stator plastic sealing component, and the fan blade rotor and the magnetic ring are integrally injection-molded to form a rotor plastic sealing component, so as to improve the integration and reduce the difficulty of assembly; 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, and there is no need for a split design like in the existing scheme, thereby avoiding the phenomenon of dynamic imbalance superposition after the wind wheel and the outer rotor are installed in the existing scheme, reducing the dynamic imbalance amount, and thus reducing the noise generated during the operation of the fan.

[0008] In one embodiment, the fan rotor is provided with a bearing, and the bearing includes an upper bearing and a lower bearing, and the upper bearing and the lower bearing are both sleeved on the shaft core.

[0009] In one of the embodiments, the interior of the plastic package body is provided with an inner cavity with an open end, and the shaft core includes an exposed end of the shaft core located in the inner cavity and extending outward along the opening of the inner cavity at one end; the fan blade rotor is provided with an inner circumferential wall with one end extending into the inner cavity, and the upper bearing and the lower bearing are both arranged on the inner circumferential wall.

[0010] In one embodiment, the interior of the inner circumferential wall forms an upper bearing chamber and a lower bearing chamber arranged around the exposed end of the shaft core, the upper bearing chamber and the lower bearing chamber are spaced apart along the axial direction of the exposed end of the shaft core, the upper bearing is arranged in the upper bearing chamber, and the lower bearing is arranged in the lower bearing chamber.

[0011] The outer rotor fan described in the utility model has the following beneficial effects: by providing an injection-molded plastic-encapsulated rotor with an upper bearing chamber and a lower bearing chamber arranged around the exposed end of the shaft core, the concentricity of the two bearing chambers is improved. When the two bearings are respectively placed in the two bearing chambers for operation, the vibration and friction of the two bearings during operation can be reduced due to the high concentricity of the two bearings, thereby reducing the noise during the operation of the fan.

[0012] In one of the embodiments, the inner cavity is provided with a lower sleeve for abutting against the inner ring of the lower bearing.

[0013] In one embodiment, both the upper bearing and the lower bearing are ball bearings.

[0014] In one of the embodiments, it also includes a volute, which has a ventilation duct and an installation port, and the installation port is connected to the ventilation duct; the plastic-sealed body includes a mounting plate and a plastic-sealed main body, and the mounting plate can be detachably installed on the mounting port, the winding stator is arranged on the plastic-sealed main body, and the plastic-sealed main body and the rotor plastic-sealed assembly are located in the ventilation duct.

[0015] The outer rotor fan described in the utility model has the following beneficial effects: by using the mounting plate to be disassembled and installed at the mounting opening of the volute to enclose a cavity with a ventilation duct, the wound stator, the plastic-sealed main body and the plastic-sealed rotor assembly are arranged in the ventilation duct, and there is no need to set up a separate motor installation space outside the volute, thereby reducing the axial size of the outer rotor motor as a whole in the axial direction of the shaft core, thereby reducing the overall volume of the outer rotor fan.

[0016] In one of the embodiments, an upper sleeve is provided on the volute, and the upper sleeve is sleeved on the outer periphery of the exposed end of the shaft core, and an elastic member is provided between the upper sleeve and the inner ring of the upper bearing.

[0017] The outer rotor fan described in the utility model has the following beneficial effects: by adding an upper sleeve at the volute to be sleeved on the outer periphery of the exposed end of the shaft core, since the shaft core is inserted into the inner cavity, the shaft core can be supported at two points, making the shaft core more reliable after installation; and by arranging the elastic member between the upper sleeve and the inner ring of the ball bearing of the upper bearing, the elastic member has the ability to provide pre-pressure for the two bearings, thereby pressing the two bearings.

[0018] In one of the embodiments, the volute is provided with an air inlet connected to the ventilation duct, the fan rotor includes a plastic-sealed rotor, a plastic-sealed wind wheel, and a plastic-sealed bridging section integrally connected between the plastic-sealed rotor and the plastic-sealed wind wheel, the plastic-sealed rotor, the plastic-sealed bridging section and the plastic-sealed wind wheel enclose an air inlet cavity that is recessed away from the air inlet; the magnetic ring is arranged on the plastic-sealed rotor.

[0019] In one embodiment, the magnetic ring includes 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 alternately arranged along the circumferential direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A cross-sectional view of the outer rotor fan provided by the utility model;

[0022] Figure 2 A cross-sectional view of a stator plastic sealing assembly in an outer rotor fan provided by the utility model;

[0023] Figure 3 A cross-sectional view of a rotor plastic sealing assembly in an outer rotor fan provided by the utility model;

[0024] Figure 4 A cross-sectional view of a volute in an external rotor fan provided by the utility model;

[0025] Figure 5 A top view of the volute in the outer rotor fan provided by the utility model.

[0026] Description of reference numerals:

[0027] 1. Stator plastic package assembly; 11. Plastic package body; 111. Inner cavity; 112. Lower shaft sleeve; 113. Mounting plate; 114. Plastic package body; 12. Winding stator; 121. Iron core; 122. Coil; 13. Shaft core; 131. Exposed end of shaft core;

[0028] 2. Plastic-sealed rotor assembly; 21. Fan blade rotor; 211. Installation cavity; 212. Inner peripheral wall; 213. Upper bearing chamber; 214. Lower bearing chamber; 215. Plastic-sealed rotor; 216. Plastic-sealed wind wheel; 217. Plastic-sealed bridge section; 218. Air inlet cavity; 22. Magnetic ring;

[0029] 31. Upper bearing; 32. Lower bearing;

[0030] 4. volute; 411. upper sleeve;

[0031] 5. Elastic parts. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0033] In the description of the present application, it should be understood that the terms "inside", "outside", "upper", "middle", "lower", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0034] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] See also Figures 1 to 5 , Figure 1 A cross-sectional view of an outer rotor fan provided by the present application is shown; Figure 2 A cross-sectional view of a stator plastic package assembly in an outer rotor fan provided by the present application is shown; Figure 3A cross-sectional view of a rotor plastic sealing assembly in an external rotor fan provided by the present application is shown; Figure 4 A cross-sectional view of a volute in an external rotor fan provided by the present application is shown; Figure 5 A top view of a volute in an external rotor blower provided in the present application is shown.

[0036] The present application provides an external rotor fan, such as Figures 1 to 3 As shown, it includes a stator plastic packaging component 1 and a rotor plastic packaging component 2. The stator plastic packaging component 1 includes an integrally injected plastic packaging body 11, a winding stator 12 and an axis core 13. The winding stator 12 and the axis core 13 are arranged on the plastic packaging body 11, and the winding stator 12 is evenly arranged around the axis core 13 along the circumferential direction; the rotor plastic packaging component 2 includes an integrally injected fan blade rotor 21 and a magnetic ring 22. The fan blade rotor 21 is provided with a bearing, the bearing sleeve is arranged on the axis core 13, and the magnetic ring 22 is arranged around the periphery of the winding stator 12.

[0037] In this way, the stator plastic package component 1 is formed by integrally injection molding the plastic package body 11, the winding stator 12 and the shaft core 13, and the rotor plastic package component 2 is formed by integrally injection molding the fan blade rotor 21 and the magnetic ring 22, thereby reducing the difficulty of assembly and improving the efficiency of assembly. At the same time, because the fan blade rotor 21 and the magnetic ring 22 are integrally injection molded to form the rotor plastic package component 2, the wind wheel and the outer rotor are an integrated component, and there is no need for a split design like in the existing scheme, thereby avoiding the phenomenon of dynamic imbalance superposition after the wind wheel and the outer rotor are installed in the existing scheme, reducing the dynamic imbalance, and thus reducing the noise generated during the operation of the fan. By adopting an integrated injection molding design, the cumulative fitting tolerance can be reduced. In the design process of the external rotor fan, the precision requirements of each component can be reduced, which is convenient for improving the qualified rate of the product.

[0038] It can be explained that if Figure 2 As shown, the plastic-encapsulated rotor 215 is provided with an installation cavity 211, which is a circular concave cavity, and the plastic-encapsulated body 114 is a circular protrusion. During installation, the plastic-encapsulated body 114 can be placed in the installation cavity 211, which can reduce the thickness of the stator plastic-encapsulated component 1 and the rotor plastic-encapsulated component 2 after assembly.

[0039] like Figure 1 and Figure 2 As shown, the wound stator 12 includes an iron core 121 and a coil 122 wound around the iron core 121 .

[0040] like Figure 1 and Figure 2 As shown, the bearing includes an upper bearing 31 and a lower bearing 32 , both of which are sleeved on the shaft core 13 , and the plastic-sealed rotor 215 is rotatably connected to the outer periphery of the shaft core 13 through the upper bearing 31 and the lower bearing 32 .

[0041] like Figure 2 and Figure 3As shown, the interior of the plastic package body 11 is provided with an inner cavity 111 with an open end, and the shaft core 13 includes an exposed shaft core end 131 located in the inner cavity 111 and extending outward along the opening of the inner cavity 111 at one end; the fan blade rotor 21 is provided with an inner circumferential wall 212 with one end extending into the inner cavity 111, and the upper bearing 31 and the lower bearing 32 are both arranged on the inner circumferential wall 212.

[0042] In one embodiment, an upper bearing chamber 213 and a lower bearing chamber 214 are formed inside the inner circumferential wall 212 and are arranged around the exposed end 131 of the shaft core. The upper bearing chamber 213 and the lower bearing chamber 214 are arranged at intervals along the axial direction of the exposed end 131 of the shaft core. The upper bearing 31 is arranged in the upper bearing chamber 213, and the lower bearing 32 is arranged in the lower bearing chamber 214.

[0043] In this way, the injection-molded plastic-encapsulated rotor 215 is provided with an upper bearing chamber 213 and a lower bearing chamber 214 arranged around the exposed end 131 of the shaft core, thereby improving the concentricity of the two bearing chambers. When the two bearings are placed in the two bearing chambers for operation, the vibration and friction of the two bearings during operation can be reduced due to the high concentricity of the two bearings, thereby reducing the noise during the operation of the fan.

[0044] It can be explained that there is no specific limitation on the selection of the upper bearing 31 and the lower bearing 32 .

[0045] As one embodiment, both the upper bearing 31 and the lower bearing 32 use ball bearings, and the ball bearings include 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 upper bearing chamber 213 or the lower bearing chamber 214, and the ball bearing inner ring is sleeved on the outer periphery of the exposed end 131 of the shaft core.

[0046] In this configuration, the bearing is configured as a ball bearing, the inner ring of the ball bearing is sleeved on the outer periphery of the exposed end 131 of the shaft core, and the outer ring of the ball bearing is fixed to the inner wall of the upper bearing chamber 213 or the lower bearing 32 .

[0047] like Figure 1 , Figure 4 and Figure 5 As shown, the external rotor fan also includes a volute 4, which has a ventilation duct and a mounting port, and the mounting port is connected to the ventilation duct; the plastic package body 11 includes a mounting plate 113 and a plastic package body 114, the mounting plate 113 is detachably mounted on the mounting port, the winding stator 12 is arranged on the plastic package body 114, and the plastic package body 114 and the rotor plastic package assembly 2 are located in the ventilation duct.

[0048] In this arrangement, by using the mounting plate 113 to be disassembled and installed at the mounting opening of the volute 4, the wound stator 12, the plastic-sealed main body 114 and the rotor plastic-sealed assembly 2 are arranged in the ventilation duct, and there is no need to set up a separate motor installation space outside the volute 4, thereby reducing the axial size of the outer rotor motor on the shaft core 13, thereby reducing the overall volume of the outer rotor fan.

[0049] It can be explained that an upper sleeve 411 is provided on the volute 4 , and the upper sleeve 411 is sleeved on the outer periphery of the exposed end 131 of the shaft core, and an elastic member 5 is provided between the upper sleeve 411 and the inner ring of the upper bearing 31 .

[0050] In this way, an upper sleeve 411 is added to the volute 4 to be sleeved on the outer periphery of the exposed end 131 of the shaft core. At this time, since the shaft core 13 is inserted into the inner cavity 111, the shaft core 13 can be supported at two points, making the shaft core 13 more reliable after installation; and the elastic member 5 is arranged between the upper sleeve 411 and the inner ring of the ball bearing of the upper bearing 31, so that the elastic member 5 has the ability to provide pre-pressure for the two bearings, compressing the two bearings to prevent the two bearings from axially moving along the shaft core 13, thereby preventing the two bearings from driving the fan blade rotor 21 to vibrate, thereby reducing the noise generated during the operation of the external rotor fan. It is understandable that in the prior art, the upper bearing 31 and the lower bearing 32 are generally fixed on the shaft core 13 by interference fit. If they are installed by interference fit, there is friction between the bearing and the shaft core 13. The lower bearing 32 is relatively low on the shaft core 13. During installation, it is necessary to overcome a large friction to install the lower bearing 32 at the lower part of the shaft core 13. Similarly, it is also necessary to overcome friction when installing the upper bearing 31, which makes installation more difficult. By setting the elastic member 5, the upper bearing 31 and the lower bearing 32 of the present application only need to be sleeved on the shaft core 13, without having to overcome a large friction, and then the upper bearing 31 is positioned by using the elastic member 5, which can be easily assembled.

[0051] It is understandable that in the prior art, the shaft core 13 is arranged on the rotor, the bearing is arranged on the stator, and for the overall stability, a metal bearing sleeve is also arranged on the stator. The present application adopts a design different from the shaft system in the prior art, by plastic-sealing the shaft core 13 as a whole on the plastic-sealed body 11, and the bearing is arranged on the fan rotor 21, which is convenient for assembly, and the elastic member 5 is used to position the upper bearing 31, which is also convenient for later maintenance.

[0052] It should be noted that there is no specific limitation on the type of the elastic member 5 .

[0053] As one of the embodiments, the elastic member 5 is selected as a spring. During installation, the fixed spring is in a compressed state, which facilitates the spring to be pressed against the inner ring of the ball bearing in the upper bearing chamber 213, thereby facilitating the alignment of the inner ring of the ball bearing with the outer ring of the ball bearing, reducing the friction generated during the rotation of the bearing, achieving smooth rotation, and further reducing the noise generated during the operation of the outer rotor fan.

[0054] Similarly, the inner cavity 111 is provided with a lower sleeve 112 for abutting against the inner ring of the lower bearing 32. Such arrangement facilitates positioning of the inner ring of the ball bearing in the lower bearing chamber 214.

[0055] like Figure 1 , Figures 3 to 5 As shown, the volute 4 is provided with an air inlet connected to the ventilation duct, and the fan rotor 21 includes a plastic-sealed rotor 215, a plastic-sealed wind wheel 216, and a plastic-sealed bridging section 217 integrally connected between the plastic-sealed rotor 215 and the plastic-sealed wind wheel 216. The plastic-sealed rotor 215, the plastic-sealed bridging section 217 and the plastic-sealed wind wheel 216 enclose an air inlet cavity 218 recessed toward the air inlet, which can easily reduce the resistance of air entering the air inlet cavity 218; the magnetic ring 22 is arranged on the plastic-sealed rotor 215.

[0056] It can be explained that the plastic-sealed wind wheel 216 includes a plurality of wind blades arranged at intervals along the circumferential direction, an air flow channel is formed between two adjacent wind blades, and the plurality of air flow channels are interconnected. When the fan rotor 21 rotates, the plastic-sealed wind wheel 216 is used to guide the air flowing into the internal ventilation duct of the volute 4 at the air inlet of the volute 4 to the air outlet of the volute.

[0057] It should be noted that in the above embodiment, the material selected for the plastic package 11 is BMC. Specifically, the wound stator 12 and the shaft core 13 obtained after assembling the iron core 121 and the coil 122 are placed in an injection mold, and injection molding is performed using the thermosetting material BMC, and the BMC material forms the plastic package 11. With such a configuration, the air can be isolated during the heat dissipation of the iron core 121 and the coil 122, thereby preventing the iron core 121 and the coil 122 from aging and corrosion; in addition, the stator plastic package assembly 1 is placed on the flow path of the air in the air channel to improve the heat dissipation effect, improve the reliability of the external rotor fan, and increase the life of the external rotor fan.

[0058] In one embodiment, the magnetic ring 22 includes 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 alternately along the circumferential direction. Specifically, at least one N-pole and at least one S-pole are plastic-sealed to obtain a magnetic ring 22 with a plastic protective layer on the outside; the magnetic ring 22 is then placed in an injection mold for injection molding to form a fan rotor 21.

[0059] During installation, take out the stator plastic package component 1 and the rotor plastic package component 2 obtained by injection molding, and press the two ball bearings into the upper bearing chamber 213 and the lower bearing chamber 214 respectively; then, sleeve the inner rings of the two ball bearings on the exposed end 131 of the shaft core; then place the spring on the inner ring of the ball bearing in the upper bearing chamber 213; then sleeve the upper shaft sleeve 411 into the exposed end 131 of the shaft core; finally, fix the volute 4 and the plastic package body 11, if the volute 4 and the plastic package body 11 are both provided with a snap-fit ​​structure, the snap-fit ​​can be completed during installation, or a threaded structure can be used to complete the connection and fixation of the volute 4 and the plastic package body 11, if the outer edge of the volute 4 and the plastic package body 11 is provided with a connecting hole, such as a threaded connecting hole, bolts can be used to complete the tightening during installation.

[0060] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The specific contents of the above specific implementations only express several implementations of the utility model, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. An external rotor fan, characterized in that: The invention comprises a stator plastic packaging component (1) and a rotor plastic packaging component (2), wherein the stator plastic packaging component (1) comprises an integrally-injected plastic packaging body (11), a winding stator (12) and an axis core (13), wherein the winding stator (12) and the axis core (13) are arranged on the plastic packaging body (11), and the winding stator (12) is evenly arranged around the axis core (13) in the circumferential direction; and the rotor plastic packaging component (2) comprises an integrally-injected fan rotor (21) and a magnetic ring (22), wherein the fan rotor (21) is rotatably connected to the axis core (13), and the magnetic ring (22) is arranged around the periphery of the winding stator (12).

2. The outer rotor fan according to claim 1, characterized in that: The fan blade rotor (21) is provided with a bearing, and the bearing comprises an upper bearing (31) and a lower bearing (32), and the upper bearing (31) and the lower bearing (32) are both sleeved on the shaft core (13).

3. The outer rotor fan according to claim 2, characterized in that: The plastic sealing body (11) is provided with an inner cavity (111) with one end being open, and the shaft core (13) comprises an exposed shaft core end (131) located in the inner cavity (111) and with one end extending outward along the opening of the inner cavity (111); the fan blade rotor (21) is provided with an inner peripheral wall (212) with one end extending into the inner cavity (111), and the upper bearing (31) and the lower bearing (32) are both arranged on the inner peripheral wall (212).

4. The outer rotor fan according to claim 3, characterized in that: An upper bearing chamber (213) and a lower bearing chamber (214) are formed inside the inner peripheral wall (212) and are arranged around the exposed end (131) of the shaft core. The upper bearing chamber (213) and the lower bearing chamber (214) are arranged at intervals along the axial direction of the exposed end (131) of the shaft core. The upper bearing (31) is arranged in the upper bearing chamber (213), and the lower bearing (32) is arranged in the lower bearing chamber (214).

5. The outer rotor fan according to claim 4, characterized in that: The inner cavity (111) is provided with a lower sleeve (112) for abutting against the inner ring of the lower bearing (32).

6. The outer rotor fan according to claim 2, characterized in that: The upper bearing (31) and the lower bearing (32) are both ball bearings.

7. The outer rotor fan according to claim 3, characterized in that: It also includes a volute (4), the volute (4) having a ventilation duct and a mounting port, the mounting port being connected to the ventilation duct; the plastic-encapsulated body (11) includes a mounting plate (113) and a plastic-encapsulated main body (114), the mounting plate (113) being detachably mounted on the mounting port, the winding stator (12) being arranged on the plastic-encapsulated main body (114), and the plastic-encapsulated main body (114) and the rotor plastic-encapsulated assembly (2) being located in the ventilation duct.

8. The outer rotor fan according to claim 7, characterized in that: An upper shaft sleeve (411) is provided on the volute (4), and the upper shaft sleeve (411) is sleeved on the outer periphery of the exposed end (131) of the shaft core. An elastic member (5) is provided between the upper shaft sleeve (411) and the inner ring of the upper bearing (31).

9. The outer rotor fan according to claim 7, characterized in that: The volute (4) is provided with an air inlet communicated with a ventilation duct; the fan rotor (21) comprises a plastic-encapsulated rotor (215), a plastic-encapsulated wind wheel (216), and a plastic-encapsulated bridge section (217) integrally connected between the plastic-encapsulated rotor (215) and the plastic-encapsulated wind wheel (216); the plastic-encapsulated rotor (215), the plastic-encapsulated bridge section (217), and the plastic-encapsulated wind wheel (216) enclose an air inlet cavity (218) that is recessed in a direction away from the air inlet; and the magnetic ring (22) is provided on the plastic-encapsulated rotor (215).

10. The outer rotor fan according to any one of claims 1 to 9, characterized in that: The magnetic ring (22) 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 alternately along the circumferential direction.

Images