TWI689155B - Outer-rotor motor - Google Patents

Abstract

An outer-rotor motor is provided for use in a large-size ceiling fan or cooling fan to improve upon the conventional outer-rotor motor in terms of weight and convenience in punching process. The outer-rotor motor includes a metallic housing made of a magnetically conductive material and receiving a stator, a permanent magnet received in the metallic housing and surrounding the stator, and at least one magnetically insulative ring surrounding a lateral wall of the metallic housing and located between the permanent magnet and the metallic housing. Alternatively, the lateral wall is located between the at least one magnetically insulative ring and the permanent magnet.

Description

External rotor motor

The invention relates to an external rotor motor, in particular to an external rotor motor used for larger ceiling fans or fans.

Generally, traditional industrial plants are located in large open working areas. In order to improve the air flow, large ceiling fans are mostly installed on the ceiling. The large ceiling fan has a metal shell, stator, a permanent magnet and a plurality of blades. The stator is arranged in the metal casing, the permanent magnet is arranged on the inner wall of the metal casing and the stator is aligned, the plurality of blades are combined with the casing, and a large area of air is caused by the rotation of the plurality of blades, In turn, the working environment in the plant can be more comfortable.

However, the volume of various components of the large ceiling fan is a larger size, wherein when the permanent magnet uses a larger size, the metal casing needs to be increased to a certain thickness to be able to seal the permanent magnet However, if the thickness of the metal shell is increased, the metal shell is difficult to be stamped and manufactured, which makes the processing difficult. In addition, the weight of the entire large ceiling fan is too large, which makes it difficult to install the large ceiling fan on the ceiling. .

In view of this, the large-scale ceiling fans of the prior art do still need to be improved.

In order to solve the above-mentioned problems, the present invention provides an external rotor motor having an external rotor motor that reduces the weight of a large ceiling fan and improves the magnetic sealing effect.

The directivity or its approximate terms in the entire text of the present invention, such as "front", "back", "left", "right", "upper (top)", "lower (bottom)", "inner", "outer" , "Side", etc., mainly refer to the directions of the attached drawings, and each directivity or its approximate terms are only used to help explain and understand the embodiments of the present invention, not to limit the present invention.

The approximate terms "combination", "combination", or "assembly" described throughout the present invention mainly include the types that can be separated without damaging the components after connection, or the components cannot be detached after connection, which is common knowledge in the art. It can be selected according to the material or assembly requirements of the components to be connected.

The outer rotor motor of the present invention is used in a large ceiling fan. The outer rotor motor includes: a metal casing made of a magnetically conductive material and having a ring wall; the metal casing is provided with stators; a permanent magnet is located in the The metal casing is provided with a ring on the outer periphery of the stator; and at least one magnetic ring is provided on the ring wall, the at least one magnetic ring is located between the permanent magnet and the metal casing, or the ring wall is located on the at least one Between a magnetic ring and the permanent magnet.

Accordingly, the outer rotor motor of the present invention utilizes the at least one magnetic ring between the permanent magnet and the metal housing, or the ring wall is located between the at least one magnetic ring and the permanent magnet to make the metal The casing and the at least one magnetic ring can simultaneously conduct magnetic leakage to the magnetic flux leakage, whereby the metal casing and the at least one magnetic ring can provide at least two layers of magnetic sealing effect, which can further improve the magnetic sealing effect, Moreover, by providing the at least one magnetic ring, the thickness of the metal casing can be reduced, and the overall weight of the large ceiling fan can be reduced, and at the same time, the problem that the metal casing is difficult to press can be avoided.

Wherein, the at least one magnetic ring ring is arranged on the outer peripheral wall of the ring wall of the metal shell, and the permanent magnet is combined with the inner peripheral wall of the ring wall of the metal shell. In this way, the at least one magnetic ring system has the effect of sealing the permanent magnet in the radial direction.

Wherein, the metal shell has a top wall, the at least one magnetic ring has a first extension, the first extension extends toward the top wall of the metal shell, and the first extension axially shields the permanent magnet. In this way, the magnetic sealing ring system has the effect of magnetically sealing the permanent magnet in the axial direction.

Wherein the metal shell has a bottom plate extending radially from the ring wall, the at least one magnetic ring has a second extension portion, the second extension portion extends radially toward the bottom plate of the metal shell, the second The extending portion has a through hole, which is penetrated by a fixing member. In this way, it has the effect of fixing the at least one magnetic ring on the metal shell.

Wherein, the at least one magnetic ring ring is arranged on the inner peripheral wall of the ring wall of the metal shell, and the permanent magnet is combined with the inner wall of the at least one magnetic ring. In this way, the at least one magnetic ring system has the effect of sealing the permanent magnet in the radial direction.

Wherein, the metal casing has a top wall, the at least one magnetic ring has a first extension portion, the first extension portion extends toward the top wall of the metal casing, and the first extension portion axially shields the permanent magnet . In this way, the at least one magnetic ring system has the effect of sealing the permanent magnet in the axial direction.

Wherein, the at least one magnetic ring is made of magnetically conductive material. In this way, it has the effect of conducting magnetic flux leakage.

Wherein, the at least one magnetic ring is tightly coupled with the metal shell. In this way, it has the effect of improving the stability of the combination.

Wherein, the at least one magnetic ring is welded to the metal shell. In this way, it has the effect of improving the stability of the combination.

Wherein, the at least one magnetic ring is screwed to the metal casing. In this way, it is easy to assemble.

Among them, the thickness of the metal shell is less than or equal to 3mm and is made by stamping. In this way, it has the effect of reducing the weight of the metal shell and being easy to manufacture.

Wherein, the total thickness of the metal shell and the at least one magnetic ring is greater than 3mm and less than or equal to 6mm. In this way, it has the effect of reducing the weight of the outer rotor motor.

Wherein the metal shell has a bottom plate extending radially from the ring wall, the at least one magnetic ring has a second extension portion, the second extension portion extends radially toward the bottom plate of the metal shell, the second The extending portion has a through hole, which is penetrated by a fixing member. In this way, it has the effect of fixing the at least one magnetic ring on the metal shell.

Wherein, a positioning element is further included, the positioning element is located in the metal casing, and the permanent magnet is positioned and combined with the positioning element. In this way, it has the effect of ensuring that the permanent magnet is positioned in the correct position.

There is a gap between the positioning member and the inner peripheral wall, and the at least one magnetic ring extends to the gap. In this way, it has the effect of enhancing the range in which the at least one magnetic ring has a magnetic sealing effect on the permanent magnet in the radial direction.

Wherein, the at least one magnetic ring has a first extension portion, the first extension portion extends toward the top of the permanent magnet, and the first extension portion is connected between the permanent magnet and the positioning member. In this way, the first extension portion has the effect of axially shielding the permanent magnet.

The number of the magnetic seal rings is two, one of the magnetic ring rings is provided on the outer wall of the metal shell, and the other magnetic ring is provided on the outer wall of the one magnetic ring. In this way, it has the effect of further improving the magnetic sealing effect and the convenience of processing.

Wherein, the ring wall of the metal shell is bent along the top of the permanent magnet to form a shoulder, the shoulder is located between the ring wall and the top wall, and the shoulder is used for positioning and combining the permanent magnet. In this way, it has the effect of ensuring that the permanent magnet is positioned in the correct position.

Wherein, one of the magnetic rings has a first extension extending radially toward the permanent magnet, and the other magnetic ring has a radial extension extending toward the first extension of the one magnetic ring. In this way, it has the effect that the one of the magnetic rings and the other of the magnetic rings can axially shield the permanent magnets and ensure that the axial height of the outer rotor motor does not increase.

In order to make the above and other objects, features and advantages of the present invention more obvious and easy to understand, the following is a detailed description of preferred embodiments of the present invention, in conjunction with the attached drawings, as follows:

Please refer to FIG. 1, which is the first embodiment of the outer rotor motor of the present invention. The outer rotor motor is used in a large ceiling fan. The outer rotor motor includes a metal casing 1, a permanent magnet 2 and at least one magnetic ring 3. The permanent magnet 2 is located in the metal casing 1, and the at least one magnetic ring 3 is ring-mounted on the metal casing 1.

Please refer to FIG. 1, the metal shell 1 is made of a magnetically conductive material, which can be used to produce a magnetic sealing effect on the permanent magnet 2. In addition, the metal shell 1 has a ring wall 10, and the ring wall 10 It has an inner peripheral wall 11 and an outer peripheral wall 12 opposite to each other. The metal casing 1 is provided with a stator 13. The stator 1 has a winding assembly 131, and the stator 13 can be combined with an axis 14 to form a ceiling fan The shaft center 14 is used to be fixed at a predetermined position such as a ceiling; alternatively, the shaft center 14 can also be combined with a rotor (not shown) to form a fan.

Please refer to FIG. 1, the permanent magnet 2 is coupled to the inner peripheral wall 11 of the metal casing 1, the permanent magnet 2 is looped around the outer periphery of the stator 13, and the permanent magnet 2 is aligned with the stator 13 and connected to the stator 13 An air gap G is formed, and when the winding assembly 131 of the stator 13 is energized, the winding assembly 131 can generate a magnetic field, and the magnetic field lines of the permanent magnet 2 enter the magnetic field of the winding assembly 131 through the air gap G to A magnetic cross-linking action is formed, which in turn can drive the metal casing 1 to rotate.

Please refer to FIG. 1, the at least one magnetic ring 3 is provided on the ring wall 10. In this embodiment, the number of the magnetic seal 3 is one, and the magnetic seal 3 is provided on the metal shell 1 The outer peripheral wall 12, the metal casing 1, the permanent magnet 2 and the magnetic seal ring 3 are all formed on a rotor R, so that the ring wall 10 of the metal casing 1 is located on the magnetic seal ring 3 and the permanent magnet 2 And the sealed magnetic ring 3 is located radially opposite to the permanent magnet 2, wherein the sealed magnetic ring 3 is made of a magnetically permeable material, when the permanent magnet 2 does not generate a magnetic cross link with the winding assembly 131 Magnetic flux leakage caused by the action, the magnetic seal ring 3 can conduct magnetic flux to the magnetic flux leakage, so that the magnetic flux leakage can form a closed magnetic circuit by the magnetic seal ring 3 to avoid the formation of the magnetic flux leakage and the winding assembly 131 High frequency resonance to reduce the high frequency noise generated when the motor rotates.

Please refer to Fig. 1 and Fig. 2 in particular, the magnetic sealing ring 3 and the metal casing 1 can be tightly fitted, welded or screwed together. In addition, the thickness of the metal casing 1 is less than or equal to 3 mm and is Made by stamping, the total thickness of the metal housing 1 and the magnetic sealing ring 3 is greater than 3 mm and less than or equal to 6 mm, thereby preventing the overall weight of the outer rotor motor from being too large.

Please refer to FIGS. 1 and 2. According to the foregoing structure, the magnetic seal ring 3 is provided around the outer peripheral wall 12 of the metal casing 1. The metal shell 1 and the magnetic seal ring 3 can protect the permanent magnet 2. The magnetic flux leakage caused by the magnetic linkage effect of the winding assembly 131 is used for magnetic conduction, whereby the metal shell 1 and the magnetic sealing ring 3 provide two layers of magnetic sealing, which can further improve the magnetic sealing effect, and The arrangement of the magnetic seal ring 3 can reduce the thickness of the metal casing 1 and further reduce the overall weight of the large ceiling fan. At the same time, the problem that the metal casing 1 is difficult to press can be avoided.

Please refer to FIG. 3, which is the second embodiment of the outer rotor motor of the present invention. The second embodiment of the present invention is substantially the same as the first embodiment described above. The main difference is that the second embodiment of the present invention The metal casing 1 has a top wall 15, the magnetic seal ring 3 has a first extension 31, the first extension 31 extends toward the top wall 15 of the metal casing 1, and the first extension 31 is axial Shield the permanent magnet 2. In this way, the first extending portion 31 can perform magnetic permeability on the magnetic flux leakage in the axial direction, so that the magnetic sealing ring 3 can produce a magnetic sealing effect on the permanent magnet 2 in both the radial direction and the axial direction, whereby the metal The housing 1 and the magnetic sealing ring 3 provide two layers of magnetic sealing, which can improve the magnetic sealing effect, and by the arrangement of the magnetic sealing ring 3, the thickness of the metal housing 1 can be reduced, which can further reduce the large size The overall weight of the ceiling fan can avoid the problem that the metal shell 1 is difficult to be stamped.

Please refer to FIG. 4, which is the third embodiment of the outer rotor motor of the present invention. The third embodiment of the present invention is substantially the same as the second embodiment described above, and the main difference is that the third embodiment of the present invention The metal casing 1 has a bottom plate 16 extending radially from the ring wall 10, and the magnetic seal ring 3 has a second extension 32 that extends radially toward the bottom plate 16 of the metal casing 1, and The second extending portion 32 has a through hole 321 which is penetrated by a fixing member 4. In this way, the magnetic sealing ring 3 can be fixedly disposed on the metal casing 1 to increase the stability of the coupling, so that the magnetic sealing ring 3 can produce a magnetic sealing effect on the permanent magnet 2 in both radial and axial directions. Thereby, the metal casing 1 and the magnetic sealing ring 3 provide two layers of magnetic sealing effect, which can further improve the magnetic sealing effect, and by setting the magnetic sealing ring 3, the thickness of the metal casing 1 can be reduced, Furthermore, the overall weight of the large ceiling fan can be reduced, and at the same time, the problem that the metal shell 1 is difficult to be stamped can be avoided.

Please refer to FIG. 5, which is the fourth embodiment of the outer rotor motor of the present invention. The fourth embodiment of the present invention is substantially the same as the first embodiment described above. The main difference is that the fourth embodiment of the present invention The metal casing 1 has a bottom plate 16 extending radially from the ring wall 10, and the magnetic seal ring 3 has a second extension 32 that extends radially toward the bottom plate 16 of the metal casing 1. The second extending portion 32 has a through hole 321 which is penetrated by a fixing member 4. In this way, the magnetic sealing ring 3 can be fixedly disposed on the metal casing 1 to increase the stability of the bonding, and ensure that the magnetic sealing ring 3 can produce a magnetic sealing effect on the permanent magnet 2 in the radial direction, whereby the metal The housing 1 and the magnetic sealing ring 3 provide two layers of magnetic sealing, which can improve the magnetic sealing effect, and by the arrangement of the magnetic sealing ring 3, the thickness of the metal housing 1 can be reduced, which can further reduce the large size The overall weight of the ceiling fan can avoid the problem that the metal shell 1 is difficult to be stamped.

Please refer to FIG. 6, which is the fifth embodiment of the outer rotor motor of the present invention. The fifth embodiment of the present invention is substantially the same as the first embodiment described above, and the main difference is that the fifth embodiment of the present invention The magnetic sealing ring 3 is set on the inner peripheral wall 11 of the metal casing 1, and the permanent magnet 2 is coupled to the inner wall 3 a of the magnetic sealing ring 3 so that the magnetic sealing ring 3 is located between the permanent magnet 2 and the metal casing 1 between the ring walls 10. In this way, both the metal shell 1 and the magnetic seal ring 3 can conduct the magnetic permeability of the magnetic flux leakage, thereby, the metal shell 1 and the magnetic seal ring 3 provide two layers of magnetic seal, which can further improve the seal The magnetic effect, and by the arrangement of the magnetic seal ring 3, the thickness of the metal casing 1 can be reduced, and the overall weight of the large ceiling fan can be reduced, and at the same time, the problem that the metal casing 1 is difficult to be stamped can be avoided. In addition, the outer rotor motor of the present invention may further include a positioning member 5 located in the metal housing 1, the positioning member 5 may be, for example, a plurality of blocks or a ring body, and the positioning member 5 is integrated into the inner At the connection between the peripheral wall 11 and the top wall 15, the permanent magnet 2 and the magnetic seal ring 3 axially abut the positioning member 5, thereby, when the permanent magnet 2 is assembled, the positioning member 5 can supply the permanent magnet 2 The positioning combination can ensure that the permanent magnet 2 is positioned at the correct position, so that the permanent magnet 2 can align the stator 13 in the radial direction.

Please refer to FIG. 7, which is the sixth embodiment of the outer rotor motor of the present invention. The sixth embodiment of the present invention is substantially the same as the fifth embodiment described above, and the main difference is that the sixth embodiment of the present invention The positioning member 5 is selectively connected to the top wall 15 so that there is a gap D between the positioning member 5 and the inner peripheral wall 11, and the magnetic seal ring 3 can extend to the gap D, by which the magnetic seal can be raised The range in which the ring 3 has a magnetic sealing effect on the permanent magnet 2 in the radial direction.

Please refer to FIG. 8, which is the seventh embodiment of the outer rotor motor of the present invention. The seventh embodiment of the present invention is substantially the same as the fifth embodiment described above, and the main difference is that the seal of the seventh embodiment of the present invention The magnetic ring 3 has a first extending portion 31 that extends toward the top of the permanent magnet 2. For example, but not limited to, in this embodiment, the positioning member 5 may also be provided in the metal housing 1 The first extension 31 is connected between the permanent magnet 2 and the positioning member 5 so that the first extension 31 can axially shield the permanent magnet 2. In this way, the first extending portion 31 can perform magnetic permeability on the magnetic flux leakage in the axial direction, so that the magnetic sealing ring 3 can produce a magnetic sealing effect on the permanent magnet 2 in both the radial direction and the axial direction, whereby the metal The housing 1 and the magnetic sealing ring 3 provide two layers of magnetic sealing, which can improve the magnetic sealing effect, and by the arrangement of the magnetic sealing ring 3, the thickness of the metal housing 1 can be reduced, which can further reduce the large size The overall weight of the ceiling fan can avoid the problem that the metal shell 1 is difficult to be stamped.

Please refer to FIG. 9, which is an eighth embodiment of the outer rotor motor of the present invention. The eighth embodiment of the present invention is substantially the same as the fourth embodiment described above, and the main difference is that the eighth embodiment of the present invention The ring wall 10 is bent along the top of the permanent magnet 2 to form a shoulder 17 between the ring wall 10 and the top wall 15. The shoulder 17 can be used for positioning and bonding the permanent magnet 2. Ensure that the permanent magnet 2 is positioned in the correct position, so that the permanent magnet 2 can align the stator 13 in the radial direction, and at the same time, the shoulder 17 can also axially shield the permanent magnet 2 to provide an axial sealing effect . In addition, the magnetic seal ring 3 does not have the second extending portion 32 as shown in FIG. 5, and the magnetic seal ring 3 is selected to be tightly fitted or glued to the outer peripheral wall 12 of the metal casing 1, so there is no need to The magnetic seal ring 3 is locked to the bottom plate 16 of the metal casing 1, so that the working time for assembling the outer rotor motor can be further saved.

Please refer to FIG. 10, which is the ninth embodiment of the outer rotor motor of the present invention. The ninth embodiment of the present invention is substantially the same as the eighth embodiment described above. The main difference is that the ninth embodiment of the present invention The number of the magnetic sealing rings 3 is two, one of the magnetic rings 3 is set on the outer peripheral wall 12 of the metal casing 1, and the other magnetic ring 3'is set on the outer wall 3b of the one magnetic ring 3, the The two magnetic rings 3, 3'are located outside the ring wall 10, so that the metal shell 1, the permanent magnet 2, the one magnetic ring 3 and the other magnetic ring 3'are formed on the rotor R on. In detail, one of the magnetic rings 3 has a first extension 31 that extends toward the shoulder 17 of the metal housing 1, and the other magnetic ring 3 ′ has a radial extension Portion 31', the radially extending portion 31' extends toward the first extending portion 31 of one of the magnetic rings 3, the first extending portion 31 and the other sealing ring 3'are sequentially stacked on the shoulder portion 17 In this way, in addition to ensuring that the axial height of the outer rotor motor does not increase, at the same time, the one of the magnetic ring 3 and the other of the magnetic ring 3'can axially shield the permanent magnet 2, which can provide Axial magnetic sealing, and the other magnetic sealing ring 3'is radially opposite to the permanent magnet 2 and the magnetic sealing ring 3, the other magnetic sealing ring 3'is made of a magnetically conductive material; The metal casing 1, the one magnetic ring 3 and the other magnetic ring 3'provide a three-layer magnetic sealing function, which can further enhance the magnetic sealing effect.

In particular, the one magnetic ring 3 may be disposed inside the metal housing 1, the other magnetic ring 3 ′ may be disposed outside the metal housing 1; or the one magnetic ring 3 and the The other magnetic ring 3'can be arranged in the metal shell 1 at the same time; or the one magnetic ring 3 and the other magnetic ring 3'can be arranged in the metal shell 1 at the same time, and the metal shell The position sequence between the body 1, the one magnetic ring 3 and the other magnetic ring 3'is not limited by the present invention. In this embodiment, the one magnetic ring 3 and the other magnetic ring The ring 3'is preferably selected to be disposed outside the metal shell 1, thereby, it can also have the effect of improving the convenience of processing.

In summary, the outer rotor motor of the present invention uses the at least one magnetic ring between the permanent magnet and the metal housing, or the ring wall is located between the at least one magnetic ring and the permanent magnet, so that The metal shell and the at least one magnetic ring can simultaneously conduct magnetic permeability to the magnetic flux leakage of the permanent magnet that does not have a magnetic interlinking effect with the winding assembly, whereby the metal shell and the at least one magnetic ring Can provide at least two layers of magnetic sealing effect, which can improve the magnetic sealing effect, and by the arrangement of the at least one magnetic ring, the thickness of the metal shell can be reduced, which can further reduce the overall weight of the large ceiling fan, and at the same time The problem that the metal shell is difficult to be stamped and processed is avoided.

Although the present invention has been disclosed using the above-mentioned preferred embodiments, it is not intended to limit the present invention. Anyone who is familiar with this art without departing from the spirit and scope of the present invention still makes various changes and modifications to the above-mentioned embodiments. The technical scope of the invention is protected, so the scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

﹝this invention﹞ 1: Metal shell 10: Ring Wall 11: Inner peripheral wall 12: peripheral wall 13: stator 131: Winding assembly 14: Axis 15: top wall 16: bottom plate 17: shoulder 2: permanent magnet 3: Seal the magnetic ring 3’: Sealing the magnetic ring 3a: inner wall 3b: outer wall 31: The first extension 31’: Radial extension 32: Second extension 321: through hole 4: fixings 5: Positioning piece D: clearance G: air gap R: rotor

[Figure 1] A cross-sectional structural view of a metal shell combined with a permanent magnet and a magnetic seal ring according to the first embodiment of the present invention. [Figure 2] Partially enlarged view of Figure A. [Figure 3] A partially enlarged view of the second embodiment of the present invention. [Figure 4] A partially enlarged view of a third embodiment of the present invention. [Figure 5] A partially enlarged view of a fourth embodiment of the present invention. [Figure 6] A partially enlarged view of a fifth embodiment of the present invention. [Figure 7] A partially enlarged view of a sixth embodiment of the present invention. [Figure 8] A partially enlarged view of a seventh embodiment of the present invention. [Figure 9] A partially enlarged view of the eighth embodiment of the present invention. [Figure 10] A partially enlarged view of a ninth embodiment of the present invention.

1: Metal shell

10: Ring Wall

11: Inner peripheral wall

12: peripheral wall

13: stator

131: Winding assembly

14: Axis

15: top wall

2: permanent magnet

3: Seal the magnetic ring

3a: inner wall

3b: outer wall

G: air gap

R: rotor

Claims (19)

An external rotor motor includes: a metal housing made of a magnetically conductive material and having a ring wall in which a stator is provided; a permanent magnet located in the metal housing and ringed around the outer periphery of the stator; and At least one magnetic ring is disposed on the ring wall, the at least one magnetic ring is located between the permanent magnet and the metal shell, or the ring wall is located between the at least one magnetic ring and the permanent magnet. The outer rotor motor as described in item 1 of the scope of the patent application, wherein the at least one magnetic ring ring is provided on the outer peripheral wall of the ring wall of the metal casing, and the permanent magnet is incorporated in the ring wall of the metal casing Zhou Bi. The outer rotor motor as described in item 2 of the patent application scope, wherein the metal housing has a top wall, and the at least one magnetic ring has a first extension portion, the first extension portion facing the top of the metal housing The wall extends, and the first extension axially shields the permanent magnet. The outer rotor motor as described in item 3 of the patent application scope, wherein the metal housing has a bottom plate extending radially from the ring wall, the at least one magnetic ring has a second extension portion, and the second extension portion Radially extending toward the bottom plate of the metal shell, the second extending portion has a through hole, and the through hole is penetrated by a fixing member. The outer rotor motor as described in item 1 of the patent application range, wherein the at least one magnetic ring ring is provided on the inner peripheral wall of the ring wall of the metal casing, and the permanent magnet is bonded to the inner wall of the at least one magnetic ring. The outer rotor motor as described in item 5 of the patent application scope, wherein the metal housing has a top wall, the at least one magnetic ring has a first extension portion, and the first extension portion faces the top of the metal housing The wall extends, and the first extension axially shields the permanent magnet. The outer rotor motor as described in item 1 of the patent application scope, wherein the at least one magnetic ring system is made of a magnetically conductive material. The outer rotor motor as described in item 1 of the patent application scope, wherein the at least one magnetic ring is tightly coupled with the metal casing. The outer rotor motor as described in item 1 of the patent application scope, wherein the at least one magnetic ring is welded to the metal housing. The outer rotor motor as described in Item 1 of the patent application scope, wherein the at least one magnetic ring is screwed to the metal housing. The outer rotor motor as described in item 1 of the patent application scope, wherein the thickness of the metal casing is less than or equal to 3 mm and is made by stamping. The outer rotor motor as described in item 1 of the patent application scope, wherein the total thickness of the metal housing and the at least one magnetic ring is greater than 3 mm and less than or equal to 6 mm. The outer rotor motor as described in item 1 of the patent scope, wherein the metal housing has a bottom plate extending radially from the ring wall, the at least one magnetic ring has a second extension portion, and the second extension portion Radially extending toward the bottom plate of the metal shell, the second extending portion has a through hole, and the through hole is penetrated by a fixing member. As described in item 1 of the patent application scope, the outer rotor motor further includes a positioning member, the positioning member is located in the metal casing, and the permanent magnet is positioned and combined with the positioning member. The outer rotor motor as described in item 14 of the patent application range, wherein there is a gap between the positioning member and the inner peripheral wall, and the at least one magnetic ring extends to the gap. The outer rotor motor as described in item 14 of the patent application scope, wherein the at least one magnetic ring has a first extension portion, the first extension portion extends toward the top of the permanent magnet, and the first extension portion is connected to the Between the permanent magnet and the positioning member. The outer rotor motor as described in item 1 of the patent application scope, wherein the number of the magnetic seal ring is two, one of the magnetic ring rings is provided on the outer peripheral wall of the metal casing, and the other magnetic ring is provided in the The outer wall of a magnetic ring. As described in Item 17 of the patent application scope, the ring wall of the metal housing is bent along the top of the permanent magnet to form a shoulder, and the shoulder is located between the ring wall and the top wall. The shoulder is used for positioning and bonding the permanent magnet. The outer rotor motor as described in item 17 or 18 of the patent application, wherein one of the magnetic rings has a first extension extending radially toward the permanent magnet, and the other magnetic ring has a radial extension It extends toward the first extension of one of the magnetic rings.

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