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 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 utility model relates to a fan, 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 installed on the outer wall of the volute. The volute is provided with an air inlet and an air outlet. A centrifugal fan wheel is provided inside the volute. The centrifugal fan wheel is connected to the air inlet and the air outlet respectively. The drive motor includes a stator, a rotor and an output shaft. The output shaft is fixed to the rotor. The stator is provided with two bearings. The bearings are sleeved on the output shaft so that the rotor is rotatably connected to the stator. Among them, one end of the output shaft extends into the volute and is detachably connected to the 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. In addition, there are many parts, which increases the assembly process. Utility Model Content

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

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

[0006] An outer rotor fan comprises a stator plastic packaging component and a rotor plastic packaging component, wherein the stator plastic packaging component comprises an integrally-injected plastic packaging body, a winding stator and an axis core, wherein 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 in the circumferential direction; the rotor plastic packaging component comprises an integrally-injected fan blade rotor and a magnetic ring, wherein the fan blade rotor is only provided with one bearing, wherein at least half of the axis core is plastic-packaged in the plastic packaging body, wherein the axis core has an exposed end of the axis core exposed outside the plastic packaging body, wherein the bearing is sleeved on the exposed end of the axis core, and wherein the bearing is staggered with the winding stator in the axial direction of the axis core; and wherein the magnetic ring is arranged around the periphery of the winding stator.

[0007] Compared with the background technology, the outer rotor fan of the utility model has the following beneficial effects: by forming the stator plastic sealing component by integral injection molding of the plastic sealing body, the winding stator and the shaft core, and forming the rotor plastic sealing component by integral injection molding of the fan blade rotor and the magnetic ring, the assembly difficulty is reduced and the assembly efficiency is improved. At the same time, because the fan blade rotor and the magnetic ring are integrally injected to form the rotor plastic sealing component, the fan 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 fan 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. At the same time, at least half of the shaft core is plastic sealed on the plastic sealing body, so that the shaft core has good support stability. While maintaining the overall size, the bearing is set on the fan blade rotor, and the bearing and the winding stator are staggered, so there is a large space, allowing a larger bearing to be used. The large-sized bearing has high reliability, can reduce the number of bearings, and further improves the assembly efficiency.

[0008] In one of the embodiments, 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 outer rotor fan described in the utility model 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 blade rotor, reducing the gravity of the fan blade rotor, and providing pre-pressure for the bearing, 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, reducing the friction generated during the rotation of the bearing, achieving smooth rotation, and reducing the noise generated during the operation of the outer 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 spacing 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 described in the utility model has the beneficial effect of: by providing an interference fit between the bearing and the exposed end of the shaft core, the bearing is prevented from being separated from the exposed end of the shaft core when rotating at a high speed, making the connection between the two more reliable.

[0013] In one of the embodiments, the fan blade 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 sealing body has an embedded portion engaged with the annular groove.

[0016] The outer rotor fan described in the utility model has the beneficial effect that an annular groove is provided on the outer peripheral surface of the shaft core, and an embedded portion engaged with the annular groove is provided on the plastic sealing body, so as to avoid axial displacement of the plastic sealing body along the shaft core when rotating, and make the connection between the two more reliable.

[0017] 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.

[0018] 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 volume of the outer rotor as a whole.

[0019] In one of the embodiments, the volute is provided with an air inlet connected to the ventilation duct, and the fan rotor includes an integrally-injected plastic-encapsulated rotor, a plastic-encapsulated wind wheel, and a plastic-encapsulated bridging section located between the plastic-encapsulated rotor and the plastic-encapsulated wind wheel, and the plastic-encapsulated rotor, the plastic-encapsulated bridging section, and the plastic-encapsulated 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-encapsulated rotor.

[0020] 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 staggered along the circumferential direction, which can improve the integration and further improve the assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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.

[0022] Figure 1 A cross-sectional view of the outer rotor fan provided by the utility model;

[0023] Figure 2A cross-sectional view of a stator plastic sealing assembly in an outer rotor fan provided by the utility model;

[0024] Figure 3 A cross-sectional view of a rotor plastic sealing assembly in an outer rotor fan provided by the utility model;

[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 utility model;

[0026] Figure 5 A cross-sectional view of the plastic-sealed rotor in the outer rotor fan provided by the utility model including the first inner peripheral wall;

[0027] Figure 6 A cross-sectional view of the volute of the external rotor fan provided by the utility model when the volute has a shaft sleeve;

[0028] Figure 7 A top view of the volute of the outer rotor fan provided by the utility model when it has a shaft sleeve;

[0029] Description of reference numerals:

[0030] 1. Stator plastic package assembly; 11. Plastic package body; 111. Embedding part; 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. Plastic-sealed rotor assembly; 21. Fan blade rotor; 211. Bearing chamber; 212. Plastic-sealed rotor; 2121. Mounting cavity; 2122. First inner peripheral wall; 2123. Second inner peripheral wall; 213. Plastic-sealed wind wheel; 214. Plastic-sealed bridge section; 215. Air inlet cavity; 22. Magnetic ring;

[0032] 3. Bearings;

[0033] 4. Volute; 411. Bushing. DETAILED DESCRIPTION

[0034] 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.

[0035] In the description of the present application, it should be understood that the terms "inside", "outside", "upper", "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.

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

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "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.

[0038] See also Figures 1 to 7 , Figure 1 A cross-sectional view of an outer rotor fan 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 fan provided in an embodiment of the present application is shown; Figure 3 A cross-sectional view of a rotor plastic sealing assembly in an outer rotor fan 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 fan provided in an embodiment of the present application is shown; Figure 5 A cross-sectional view of a plastic-encapsulated rotor in an outer rotor fan provided in an embodiment of the present application including a first inner peripheral wall is shown; Figure 6 A cross-sectional view of a volute in an outer rotor fan provided in an embodiment of the present application when the volute has a shaft sleeve is shown; Figure 7 A top view of the volute of the external rotor fan provided in the present application is shown with a shaft sleeve.

[0039] The present 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 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 only provided with a bearing 3. At least half of the axis core 13 is plastic-sealed in the plastic packaging body 11. The axis core 13 has an exposed axis core end 131 exposed to the outside of the plastic packaging body 11. The bearing 3 is sleeved on the exposed axis core end 131, and the bearing 3 is staggered with the winding stator 12 in the axial direction of the axis core 13; the magnetic ring 22 is arranged around the outer periphery of the winding stator 12.

[0040] In this way, by integrally injecting the plastic package body 11, the winding stator 12 and the shaft core 13 to form the stator plastic package component 1, and integrally injecting the fan blade 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 blade 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 thereby 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 arranged on the rotor, and the bearing 3 is arranged on the stator. Due to the influence of the stator installation space, only a smaller-sized bearing 3 can be used. For the overall stability, two bearings 3 need to be arranged. 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 arranged 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, and thus there is a larger space. Under the condition of basically not changing the overall size, a larger-sized bearing 3 can be used. The large-sized bearing 3 has high reliability and strong balance, and thus the number of bearings 3 can be reduced, further improving the 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 , and 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, facilitating 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 implementation manner, the bearing 3 is a ball bearing.

[0045] Specifically, Figure 1 and Figure 4 As shown, the distance 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 L.

[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 is interference fit with the exposed end 131 of the shaft core. This arrangement prevents the bearing 3 from being separated from the exposed end 131 of the shaft core when rotating at high speed, making the connection between the two more reliable. In other embodiments, the bearing 3 can also be installed on the exposed end 131 of the shaft core through a retaining spring.

[0049] like Figure 1 , Figures 4 to 6 As shown, the fan blade 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. In this arrangement, since the bearing 3 is placed in the bearing chamber 211 and is inside the plastic-sealed rotor 212, a larger bearing 3 can be selected, which is convenient for making the connection relationship more reliable after the bearing 3 is installed and reducing noise.

[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, 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 arrangement, the outer ring is embedded and fixed on the inner wall of the bearing chamber 211, and the inner ring is sleeved on the outer periphery of the exposed end 131 of the shaft core, so that the shaft core 13 can be radially limited to the bearing 3. By providing a boss 114 abutting against the inner ring of the ball bearing at the plastic-sealed body 11, the bearing 3 can be axially limited to the shaft core 13, so that the connection relationship between the bearing 3, the shaft core 13, the plastic-sealed body 11, and the 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 recessed annular groove 132, and the plastic package body 11 has an embedded portion 111 engaged with the annular groove 132. Such a configuration 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 on the mounting port, the winding 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] In this 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-sealed main body 113 and the rotor plastic-sealed assembly 2 extend 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 on the shaft core 13 and thus reducing the overall volume of the outer rotor fan.

[0055] In one embodiment, the stator plastic packaging component 1 is made of thermosetting material BMC, which is convenient for heat dissipation of the iron core 121 and the coil 122 in the plastic packaging body 113, and can isolate the air to prevent aging and corrosion. At the same time, the plastic packaging body 113 is located in the ventilation duct, which can further enhance the heat dissipation effect of the iron core 121 and the coil 122, thereby improving the service life.

[0056] It can be explained that the structure of the volute 4 is not specifically limited.

[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 combined with the plastic-encapsulated body 113 and the plastic-encapsulated rotor 212 to fix the shaft core 13. It can limit the axial or radial displacement of the shaft core 13 during operation, and further improve the stability of the shaft core 13.

[0059] In one embodiment, if Figure 1 and Figure 3 As shown, the fan blade rotor 21 includes an integrally-injected plastic-encapsulated rotor 212, a plastic-encapsulated wind wheel 213, and a plastic-encapsulated bridging section 214 located between the plastic-encapsulated rotor 212 and the plastic-encapsulated wind wheel 213; the plastic-encapsulated rotor 212, the plastic-encapsulated bridging section 214, and the plastic-encapsulated wind wheel 213 enclose an air inlet cavity 215 that is recessed in a direction away from the air inlet; the magnetic ring 22 is disposed on the plastic-encapsulated 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, and 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 in a circular ring shape, and 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 staggered 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.

[0062] In one embodiment, if Figure 1 and Figure 5 As shown, the inner side end of the 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 encapsulated body 113, and the bearing chamber 211 is formed on the first inner peripheral wall 2122 of the encapsulated rotor 212. In other embodiments, such as Figure 1 and Figure 3 As shown, the inner side end of the encapsulated rotor 212 close to the shaft core 13 is provided with a second inner peripheral wall 2123 extending away from the encapsulated body 113 along the axial direction of the shaft core 13, and the bearing chamber 211 is formed on the second inner peripheral wall 2123 of the encapsulated rotor 212. In this way, the bearing chamber 211 is formed on the first inner peripheral wall 2122 or the second inner peripheral wall 2123 of the encapsulated rotor 212. Since the space where the encapsulated rotor 212 is located above the encapsulated body 113 is relatively large, the space of the formed bearing chamber 211 is also relatively large, which is convenient for placing a larger-sized bearing 3, so as to improve the stability of the encapsulated rotor 212 during rotation and reduce noise.

[0063] It can be explained that the plastic-encapsulated body 113 is wrapped around the outer circumference of the shaft core 13 , and the inner wall of the plastic-encapsulated 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-sealed body 113 with the main body of the shaft core 13, the volume of the internal cavity of the plastic-sealed body 113 is reduced, the structural strength of the plastic-sealed body 113 is improved, and the life of the plastic-sealed 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, take out the stator plastic package component 1 and the rotor plastic package component 2 obtained by injection molding, and press the ball bearing into the bearing chamber 211; then set the inner ring of the ball bearing on the exposed end 131 of the shaft core; finally, complete the fixation of 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 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 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 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 offset from the winding stator (12) in the axial direction of the shaft core (13); and the magnetic ring (22) is arranged around the outer 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 distance 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 L, and 1mm≤L≤5mm.

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

5. The outer rotor fan according to claim 1, characterized in that: The fan blade 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 sealing 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: 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 (112) and a plastic-encapsulated main body (113), the mounting plate (112) being detachably mounted on the mounting port, the winding stator (12) being arranged on the plastic-encapsulated main body (113), and the plastic-encapsulated main body (113) and the rotor plastic-encapsulated 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 blade 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); the plastic-encapsulated rotor (212), the plastic-encapsulated bridge section (214), and the plastic-encapsulated wind wheel (213) enclose an air inlet cavity (215) that is recessed in a direction away from the air inlet; and the magnetic ring (22) is arranged on the plastic-encapsulated rotor (212).

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.

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