Outer rotor fan

Abstract

The invention 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 integration degree of the outer rotor fan is improved, the production procedures can be reduced, the assembly difficulty is reduced, the assembly efficiency is improved, and the installation precision is improved; meanwhile, the fan blade rotor and the magnetic ring are subjected to integral injection molding to form a rotor plastic package assembly, so that the wind wheel and the outer rotor are an integral component, the dynamic unbalance amount is reduced, and noise generated in the working process of the fan is further reduced; and the bearing is sleeved at the exposed end of the shaft core, and the exposed end of the shaft core is arranged outside the plastic package body, so that the number of the bearings can be reduced, and the assembly is convenient.

Description

Technical Field

[0001] The present invention relates to a fan, in particular to an outer rotor fan. Background Art

[0002] The air supply fan in a gas water heater typically consists of a volute and a drive motor. The drive motor is mounted on the outer wall of the volute, which is equipped with an air inlet and outlet. A centrifugal impeller is housed within the volute, connected to the air inlet and outlet, respectively. The drive motor comprises a stator, a rotor, and an output shaft. The output shaft is fixed to the rotor. The stator has two bearings that fit over the output shaft, allowing the rotor to rotate and connect to the stator. One end of the output shaft extends into the volute and is detachably connected to the centrifugal impeller.

[0003] Since the centrifugal fan wheel and the rotor of the drive 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 dynamic imbalance of the two rotating components is superimposed, which easily causes the fan to vibrate and generate noise. In addition, there are many parts, which increases the assembly process. Summary of the Invention

[0004] The present invention provides an outer rotor fan, which can reduce noise generated by vibration of the fan and improve assembly efficiency.

[0005] The first technical problem mentioned above is solved by the following technical solution:

[0006] An external rotor fan includes a stator plastic packaging assembly and a rotor plastic packaging assembly, the stator plastic packaging assembly includes an integrally injected plastic packaging body, a wound stator and a shaft core, the wound stator and the shaft core are arranged on the plastic packaging body, and the wound stator is evenly arranged around the shaft core along the circumferential direction; the rotor plastic packaging assembly includes an integrally injected fan blade rotor and a magnetic ring, the fan blade rotor is only provided with one bearing, at least half of the shaft core is plastic-sealed in the plastic packaging body, the shaft core has an exposed shaft core end exposed from the plastic packaging body, the bearing is sleeved on the exposed shaft core end, and the bearing is staggered with the wound stator in the axial direction of the shaft core; the magnetic ring is arranged around the periphery of the wound stator.

[0007] Compared with the background art, the external rotor fan of the present invention has the following beneficial effects: by integrally injecting the plastic encapsulation body, the wound stator, and the shaft core into a stator plastic encapsulation assembly, and integrally injecting the fan rotor and the magnetic ring into a rotor plastic encapsulation assembly, the assembly difficulty is reduced and the assembly efficiency is improved. At the same time, because the fan rotor and the magnetic ring are integrally injected into the rotor plastic encapsulation assembly, the fan wheel and the external rotor are integrated components, eliminating the need for a separate design as in the existing solution. This avoids the phenomenon of dynamic imbalance superposition after the fan wheel and the external rotor are installed in the existing solution, reduces the dynamic imbalance, and thus reduces the noise generated during the operation of the fan. At the same time, at least half of the shaft core is plastic encapsulated in the plastic encapsulation body, which provides good support stability for the shaft core. While maintaining the overall size, the bearing is arranged on the fan rotor. The bearing and the wound stator are staggered, providing a larger space, allowing the use of a larger-sized bearing. The large-sized bearing has high reliability, can reduce the number of bearings, and further improves assembly efficiency.

[0008] In one embodiment, the wound stator includes an iron core and a coil wound around the iron core, and the magnetic center line of the iron core and the magnetic center line of the magnetic ring are staggered in the axial direction of the shaft core.

[0009] The external rotor fan described in the present invention has the following beneficial effects: by staggering the magnetic center line of the iron core and the magnetic center line of the magnetic ring in the axial direction of the shaft core, the magnetic force generated acts on the fan rotor, reducing the gravity of the fan rotor, and providing pre-pressure for the bearing, so that the inner ring of the ball bearing and the outer ring of the ball bearing are axially flush with the shaft core, reducing the friction generated during the rotation of the bearing, achieving smooth rotation, and reducing the noise generated during the operation of the external rotor fan.

[0010] In one embodiment, the magnetic center line of the iron core and the magnetic center line of the magnetic ring are offset by a distance L in the axial direction of the shaft core, 1mm≤L≤5mm.

[0011] In one embodiment, the bearing is interference fit with the exposed end of the shaft core.

[0012] The outer rotor fan of the present invention has the beneficial effect of preventing the bearing from separating from the exposed end of the shaft core during high-speed rotation by providing an interference fit between the bearing and the exposed end of the shaft core, thereby making the connection between the two more reliable.

[0013] In one embodiment, the fan rotor is formed with a bearing chamber arranged around the exposed end of the shaft core, and the bearing is arranged in the bearing chamber.

[0014] In one embodiment, the bearing is a ball bearing.

[0015] In one embodiment, the outer peripheral surface of the shaft core is provided with an inwardly recessed annular groove, and the plastic package body has an embedded portion engaged with the annular groove.

[0016] The external rotor fan described in the present invention has the following beneficial effects: by providing an annular groove on the outer peripheral surface of the shaft core and providing an embedded portion on the plastic package body that engages with the annular groove, the plastic package body is prevented from axially shifting along the shaft core when rotating, making the connection between the two more reliable.

[0017] In one embodiment, 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.

[0018] The external rotor fan described in the present invention 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 external rotor motor as a whole in the shaft core, and thus reducing the volume of the external rotor as a whole.

[0019] In one embodiment, the volute is provided with an air inlet connected to the ventilation duct, and the fan rotor includes an integrally injection-molded plastic rotor, a plastic wind wheel, and a plastic bridge section located between the plastic rotor and the plastic wind wheel. The plastic rotor, the plastic bridge section, and the plastic wind wheel enclose an air inlet cavity that is recessed in the direction of the air inlet; the magnetic ring is arranged on the plastic rotor.

[0020] In one embodiment, the magnetic ring includes at least one set of N-pole magnetic steel and S-pole magnetic steel, and the N-pole magnetic steel and the S-pole magnetic steel are staggered along the circumferential direction, thereby increasing the integration level and further improving the assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A cross-sectional view of the outer rotor blower provided by the present invention;

[0023] Figure 2 A cross-sectional view of a stator plastic package assembly in an external rotor blower provided by the present invention;

[0024] Figure 3 A cross-sectional view of a rotor plastic package assembly in an external rotor blower provided by the present invention;

[0025] Figure 4 A schematic diagram of the magnetic center line of the magnetic ring and the magnetic center line of the iron core in the outer rotor fan provided by the present invention;

[0026] Figure 5 A cross-sectional view of the plastic-encapsulated rotor in the outer rotor blower provided by the present invention including the first inner peripheral wall;

[0027] Figure 6 A cross-sectional view of the volute of the external rotor blower provided by the present invention with a shaft sleeve;

[0028] Figure 7 A top view of the volute of the external rotor fan provided by the present invention with a shaft sleeve;

[0029] Description of reference numerals:

[0030] 1. Stator plastic package assembly; 11. Plastic package body; 111. Embedded portion; 112. Mounting plate; 113. Plastic package body; 114. Boss; 12. Winding stator; 121. Iron core; 122. Coil; 13. Shaft core; 131. Shaft core exposed end; 132. Ring groove;

[0031] 2. Rotor plastic package assembly; 21. Fan blade rotor; 211. Bearing chamber; 212. Plastic package rotor; 2121. Mounting cavity; 2122. First inner circumferential wall; 2123. Second inner circumferential wall; 213. Plastic package wind wheel; 214. Plastic package bridge section; 215. Air inlet cavity; 22. Magnetic ring;

[0032] 3. Bearings;

[0033] 4. Volute; 411. Shaft sleeve. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0035] In the description of this application, it should be understood that the terms "inside", "outside", "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0036] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0038] See Figures 1 to 7 , Figure 1 A cross-sectional view of an outer rotor blower provided in an embodiment of the present application is shown; Figure 2 A cross-sectional view of a stator plastic package assembly in an outer rotor blower provided in an embodiment of the present application is shown; Figure 3 A cross-sectional view of a rotor plastic package assembly in an outer rotor blower provided in an embodiment of the present application is shown; Figure 4 A schematic diagram showing the magnetic center line of the magnetic ring and the magnetic center line of the iron core in the outer rotor blower provided in an embodiment of the present application is shown; Figure 5 A cross-sectional view of the outer rotor blower provided in an embodiment of the present application is shown, in which the plastic-encapsulated rotor includes a first inner peripheral wall; Figure 6 A cross-sectional view of a volute with a shaft sleeve in an outer rotor blower provided in an embodiment of the present application is shown; Figure 7 A top view of the volute of the external rotor blower provided in the present application with a shaft sleeve is shown.

[0039] This application provides an external rotor fan, such as Figures 1 to 3As 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 a shaft core 13. The winding stator 12 and the shaft core 13 are arranged on the plastic packaging body 11, and the winding stator 12 is evenly arranged around the shaft core 13 along the circumferential direction; the rotor plastic packaging component 2 includes an integrally injected fan rotor 21 and a magnetic ring 22. The fan rotor 21 is only provided with a bearing 3. At least half of the shaft core 13 is plastic-sealed in the plastic packaging body 11. The shaft core 13 has an exposed shaft core end 131 that is exposed from the plastic packaging body 11. The bearing 3 is sleeved on the exposed shaft core end 131, and the bearing 3 is staggered with the winding stator 12 in the axial direction of the shaft core 13; the magnetic ring 22 is arranged around the periphery of the winding stator 12.

[0040] With such a configuration, by integrally injecting the plastic package body 11, the wound stator 12 and the shaft core 13 to form the stator plastic package component 1, and integrally injecting the fan rotor 21 and the magnetic ring 22 to form the rotor plastic package component 2, the production process can be reduced, the assembly difficulty is reduced, the assembly efficiency is improved, and the installation accuracy is improved. At the same time, because the fan rotor 21 and the magnetic ring 22 are integrally injected to form the rotor plastic package component 2, the fan wheel and the outer rotor are an integrated component, and there is no need for a split design like in the existing solution, thereby avoiding the phenomenon of dynamic imbalance superposition after the fan wheel and the outer rotor are installed in the existing solution, reducing the dynamic imbalance amount, and thus reducing the noise generated during the operation of the fan; and by sleeve-arranging the bearing 3 on 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, the integration level of the outer rotor fan is improved.

[0041] It is understandable that in the prior art, the shaft core 13 is set on the rotor and the bearing 3 is set on the stator. Due to the influence of the stator installation space, the bearing 3 can only use a smaller size. For the overall stability, two bearings 3 need to be set. The present application adopts a design different from the shaft system in the prior art. By plastic-sealing at least half of the shaft core 13 on the plastic sealing body 11, the shaft core 13 has good support stability, and the bearing 3 is set on the fan rotor 21. The bearing 3 is staggered with the winding stator 12 in the axial direction of the shaft core 13, which can effectively avoid the influence of the winding stator 12 on the installation of the shaft core 13, thereby having a larger space. Without basically changing the overall size, a larger size bearing 3 can be used. The large-size bearing 3 has high reliability and strong balance, which can reduce the number of bearings 3 and further improve assembly efficiency.

[0042] like Figure 1 and Figure 3 As shown, the wound stator 12 includes an iron core 121 and a coil 122 wound around the iron core 121 . The magnetic center line of the iron core 121 and the magnetic center line of the magnetic ring 22 are staggered in the axial direction of the shaft core 13 .

[0043] In this arrangement, by staggering the magnetic center line of the iron core 121 and the magnetic center line of the magnetic ring 22 in the axial direction of the shaft core 13, the generated magnetic force acts on the bearing 3, providing pre-pressure for the bearing 3, making it easier for the inner ring of the ball bearing and the outer ring of the ball bearing to be axially flush with the shaft core 13, reducing the friction generated during the rotation of the bearing 3, achieving smooth rotation, and reducing the noise generated during the operation of the external rotor fan.

[0044] As one embodiment, the bearing 3 is a ball bearing.

[0045] Specifically, if Figure 1 and Figure 4 As shown, the distance L between the magnetic center line of the iron core 121 and the magnetic center line of the magnetic ring 22 in the axial direction of the shaft core 13 is offset.

[0046] It can be explained that there is no specific limitation on the value range of the spacing L, which can be determined based on actual requirements of the external rotor fan.

[0047] As one implementation manner, 1mm≤L≤5mm.

[0048] like Figure 1 、 Figure 2 、 Figures 4 to 6 As shown, the bearing 3 has an interference fit with the exposed end 131 of the shaft core. This arrangement prevents the bearing 3 from separating from the exposed end 131 of the shaft core during high-speed rotation, making the connection between the two more reliable. In other embodiments, the bearing 3 can also be mounted on the exposed end 131 of the shaft core using a retaining spring.

[0049] like Figure 1 、 Figures 4 to 6 As shown, the fan rotor 21 is formed with a bearing chamber 211 arranged around the exposed end 131 of the shaft core, and the bearing 3 is disposed in the bearing chamber 211. This arrangement allows the bearing 3 to be placed in the bearing chamber 211, inside the plastic-encapsulated rotor 212, and a larger bearing 3 can be selected, which facilitates a more reliable connection and reduces noise after the bearing 3 is installed.

[0050] Furthermore, the ball bearing includes 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, and the ball bearing inner ring is sleeved on the outer periphery of the exposed end 131 of the shaft core; the plastic sealing body 11 is provided with a boss 114, and the boss 114 is sleeved on the outer periphery of the exposed end 131 of the shaft core, and the boss 114 is used to abut the ball bearing inner ring.

[0051] With such an arrangement, by embedding and fixing the outer ring on the inner wall of the bearing chamber 211 and sleeved on the outer periphery of the exposed end 131 of the shaft core, it is convenient to radially limit the bearing 3 on the shaft core 13, and by providing a boss 114 abutting against the inner ring of the ball bearing on the plastic-sealed body 11, it is convenient to axially limit the bearing 3 on the shaft core 13, so that the connection relationship between the bearing 3, shaft core 13, plastic-sealed body 11 and plastic-sealed rotor 212 after assembly is more reliable.

[0052] like Figure 1 、 Figure 2 、 Figures 4 to 6 As shown, the outer peripheral surface of the shaft core 13 is provided with an inwardly concave annular groove 132, and the plastic package body 11 has an embedded portion 111 that engages with the annular groove 132. Such a setting prevents the plastic package body 11 from axially shifting along the shaft core 13 when rotating, making the connection between the two more reliable.

[0053] like Figure 1 、 Figures 4 to 7 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 112 and a plastic package body 113, the mounting plate 112 can be detachably installed at the mounting port, the wound stator 12 is arranged on the plastic package body 113, and the plastic package body 113 and the rotor plastic package assembly 2 are located in the ventilation duct.

[0054] With such an arrangement, by using the mounting plate 112 to be disassembled and installed at the mounting opening of the volute 4, the wound stator 12, the plastic-encapsulated main body 113 and the rotor plastic-encapsulated assembly 2 are extended into the ventilation duct, and there is no need to set up an additional installation space for the drive motor outside the volute 4, thereby reducing the axial size of the outer rotor fan unit on the shaft core 13, thereby reducing the overall volume of the outer rotor fan unit.

[0055] In one embodiment, the stator molding assembly 1 is molded of a thermosetting material BMC, which facilitates heat dissipation of the iron core 121 and the coil 122 in the molding body 113, while isolating the iron core 121 and the coil 122 from the air and preventing them from aging or corrosion. Furthermore, the molding body 113 is located in a ventilation duct, which can further enhance the heat dissipation effect of the iron core 121 and the coil 122, thereby increasing their service life.

[0056] It can be noted that there is no specific limitation on the structure of the volute 4 .

[0057] As one of the implementation methods, Figure 1 、 Figure 4 and Figure 5 As shown, the top wall of the volute 4 is provided with an air inlet connected to the ventilation duct, and the air inlet can be square or circular.

[0058] As another embodiment, Figure 6 and Figure 7As shown, a sleeve 411 is provided at the air inlet of the volute 4. The sleeve 411 is used to be sleeved on the outer periphery of the exposed end 131 of the shaft core, and is used in conjunction with the plastic-sealed body 113 and the plastic-sealed rotor 212 to fix the shaft core 13. It can limit the axial or radial displacement of the shaft core 13 during operation, further improving the stability of the shaft core 13.

[0059] In one embodiment, Figure 1 and Figure 3 As shown, the fan rotor 21 includes an integrally injection-molded plastic rotor 212, a plastic wind wheel 213, and a plastic bridge section 214 located between the plastic rotor 212 and the plastic wind wheel 213. The plastic rotor 212, the plastic bridge section 214, and the plastic wind wheel 213 enclose an air inlet cavity 215 that is recessed away from the air inlet. The magnetic ring 22 is arranged on the plastic rotor 212.

[0060] It can be explained that, if Figure 3 As shown, the plastic-encapsulated rotor 212 is provided with an installation cavity 2121 , which is a cylindrical concave cavity. The plastic-encapsulated body 113 is a cylindrical boss. During installation, the plastic-encapsulated body 113 is placed in the installation cavity 2121 .

[0061] In one embodiment, the magnetic ring 22 is annular and includes at least one set of north-pole magnets and south-pole magnets, which are staggered along the circumference. Specifically, at least one north-pole and at least one south-pole are plastic-encapsulated to form the magnetic ring 22 with a plastic protective layer. The magnetic ring 22 is then placed in an injection mold for injection molding to form the fan rotor 21.

[0062] In one embodiment, Figure 1 and Figure 5 As shown, the inner side end of the plastic-encapsulated rotor 212 close to the shaft core 13 is provided with a first inner peripheral wall 2122 extending along the axial direction of the shaft core 13 close to the plastic-encapsulated body 113, and the bearing chamber 211 is formed on the first inner peripheral wall 2122 of the plastic-encapsulated rotor 212. In other embodiments, such as Figure 1 and Figure 3 As shown, the inner end of the encapsulated rotor 212, near the shaft core 13, is provided with a second inner circumferential wall 2123 extending axially along the shaft core 13 away from the encapsulated body 113. The bearing chamber 211 is formed on the second inner circumferential wall 2123 of the encapsulated rotor 212. With this arrangement, the bearing chamber 211 is formed on either the first inner circumferential wall 2122 or the second inner circumferential wall 2123 of the encapsulated rotor 212. Because the space above the encapsulated body 113 where the encapsulated rotor 212 is located is relatively large, the space formed in the bearing chamber 211 is also relatively large, making it convenient to accommodate a larger bearing 3, thereby improving the stability of the encapsulated rotor 212 during rotation and reducing noise.

[0063] It can be explained that the plastic package body 113 is wrapped around the outer periphery of the shaft core 13 , and the inner wall of the plastic package body 113 and the outer wall of the shaft core 13 are fitted together.

[0064] In this way, by fitting the inner wall of the plastic-encapsulated body 113 with the main body of the shaft core 13, the volume of the internal cavity of the plastic-encapsulated body 113 is reduced, the structural strength of the plastic-encapsulated body 113 is improved, and the life of the plastic-encapsulated body 113 is improved. The structure of the outer rotor fan is made more reliable, and the shaft core 13 has a more stable supporting force.

[0065] During installation, the stator plastic package component 1 and the rotor plastic package component 2 obtained by injection molding are taken out, and the ball bearing is pressed into the bearing chamber 211; then the inner ring of the ball bearing is set on the exposed end 131 of the shaft core; finally, the volute 4 and the plastic package body 11 are fixed. 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 connection 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 connection hole, such as a threaded connection hole, bolts can be used to complete the tightening during installation. In addition, if a shaft sleeve 411 is provided at the volute 4, the shaft sleeve 411 needs to be inserted into the exposed end 131 of the shaft core before completing the installation of the volute 4 and the plastic package body 11.

[0066] 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.

[0067] The specific contents of the above-mentioned specific embodiments merely represent several embodiments of the present invention. While the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the scope of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the appended 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 uniformly arranged around the axis core (13) along the circumferential direction; and the rotor plastic packaging component (2) comprises an integrally-injected fan blade rotor (21) and a magnetic ring (22), wherein the fan blade The rotor (21) is provided with only one bearing (3); at least half of the shaft core (13) is plastic-sealed in the plastic-sealed body (11); the shaft core (13) has an exposed shaft core end (131) exposed from the plastic-sealed body (11); the bearing (3) is sleeved on the exposed shaft core end (131); and the bearing (3) is staggered with the winding stator (12) in the axial direction of the shaft 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 winding stator (12) comprises an iron core (121) and a coil (122) wound around the iron core (121); the magnetic center line of the iron core (121) and the magnetic center line of the magnetic ring (22) are staggered in the axial direction of the shaft core (13).

3. The outer rotor fan according to claim 2, characterized in that: The magnetic center line of the iron core (121) and the magnetic center line of the magnetic ring (22) are offset by a distance L in the axial direction of the shaft core (13), 1mm≤L≤5mm.

4. The outer rotor fan according to claim 1, characterized in that: The bearing (3) is interference-fitted with the exposed end (131) of the shaft core.

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

6. The outer 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, characterized in that: The outer peripheral surface of the shaft core (13) is provided with an inwardly recessed annular groove (132), 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, characterized in that: The invention also includes a volute (4), the volute (4) having a ventilation duct and a mounting port, the mounting port being in communication with the ventilation duct; the plastic-sealed body (11) includes a mounting plate (112) and a plastic-sealed main body (113), the mounting plate (112) being detachably mounted on the mounting port, the winding stator (12) being arranged on the plastic-sealed main body (113), and the plastic-sealed main body (113) and the rotor plastic-sealed assembly (2) being located in the ventilation duct.

9. The outer rotor fan according to claim 8, characterized in that: The volute (4) is provided with an air inlet communicated with a ventilation duct; the fan rotor (21) comprises an integrally-injected plastic-encapsulated rotor (212), a plastic-encapsulated wind wheel (213), and a plastic-encapsulated bridge section (214) located between the plastic-encapsulated rotor (212) and the plastic-encapsulated wind wheel (213); an air inlet cavity (215) recessed in a direction away from the air inlet is formed between the plastic-encapsulated rotor (212), the plastic-encapsulated bridge section (214), and the plastic-encapsulated wind wheel (213); and the magnetic ring (22) is provided on the plastic-encapsulated rotor (212).

10. The outer rotor blower 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 staggered along the circumferential direction.

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