External rotor motor

Abstract

The utility model provides an external rotor motor. The external rotor motor comprises an end cover, a motor shaft and a stator, an inner through hole, a first bearing chamber and a second bearing chamber are formed in the end cover, the first bearing chamber and the second bearing chamber are distributed at the two ends of the inner through hole at intervals along the axis of the inner through hole and communicate with the inner through hole, and an annular positioning groove is formed in the outer wall of the end cover. The positioning groove extends from the first end of the end cover to the middle of the end cover, and the first bearing chamber is located at the first end of the end cover. The middle part of the motor shaft is positioned in the inner through hole and is connected with the end cover; and the stator is positioned in the positioning groove, and the stator is riveted with the end cover. The performance of the external rotor motor provided by the utility model is superior to that of a conventional external rotor motor, the shaft diameter is larger than that of the conventional external rotor motor, and the service life is longer than that of the conventional external rotor motor.

Description

Technical Field

[0001] The present disclosure relates to the technical field of motor manufacturing, and in particular to an outer rotor motor. Background Art

[0002] An external rotor motor is a motor with the stator inside and the rotor outside. External rotor motors have the advantages of large moment of inertia, large torque and direct drive, and have been widely used in the motor industry in recent years.

[0003] In the related art, an outer rotor motor includes a motor shaft, a rotor, a stator, and an end cover. The end cover is columnar and has two bearing chambers. A bearing is installed in each bearing chamber. The bearing is used to rotatably cover the end cover outside the motor shaft. The stator is covered outside a part of the end cover and is bonded to the end cover by glue or the like. The rotor is covered outside the stator and is connected to one end of the motor shaft. During the operation of the outer rotor motor, the motor shaft rotates together with the rotor.

[0004] Since the stator and the end cover are assembled together by glue, when the outer rotor motor is used for a period of time, the glue will fall off due to the influence of the external environment, causing the stator and the end cover to separate, thereby affecting the use of the outer rotor motor. Utility Model Content

[0005] The embodiment of the present disclosure provides an outer rotor motor, which can extend the service life of the outer rotor motor and improve reliability. The technical solution is as follows:

[0006] An embodiment of the present disclosure provides an outer rotor motor, which includes an end cover, a motor shaft and a stator; the interior of the end cover is respectively provided with an inner through hole, a first bearing chamber and a second bearing chamber, the first bearing chamber and the second bearing chamber are distributed at both ends of the inner through hole along the axis of the inner through hole, and are both connected to the inner through hole, the outer wall of the end cover has an annular positioning groove, the positioning groove extends from the first end of the end cover toward the middle of the end cover, and the first bearing chamber is located at the first end of the end cover; the middle part of the motor shaft is located in the inner through hole and is connected to the end cover; the stator is located in the positioning groove, and the stator is riveted to the end cover.

[0007] In another implementation of the present disclosure, the inner circumferential wall of the inner through hole of the stator is provided with a plurality of riveting grooves, and the plurality of riveting grooves are circumferentially spaced apart on the inner circumferential wall of the inner hole of the stator; the outer wall of the end cover is provided with a plurality of riveting protrusions, and the plurality of riveting protrusions are circumferentially spaced apart on the outer groove wall of the positioning groove with the axis of the inner through hole as the axis, the plurality of riveting protrusions correspond one-to-one to the plurality of riveting grooves, and the riveting protrusions are located in the corresponding riveting grooves.

[0008] In yet another implementation of the present disclosure, the end cover is a soft metal structural member.

[0009] In another implementation of the present disclosure, the positioning groove is a tapered groove, and along the direction from the first bearing chamber to the second bearing chamber, the distance between the outer groove wall of the positioning groove and the axis of the inner through hole gradually increases.

[0010] In another implementation of the present disclosure, in the radial direction of the inner through hole, the interval between the inner circumferential wall of the first bearing chamber and the outer groove wall of the positioning groove is no more than 1 mm.

[0011] In another implementation of the present disclosure, the end cover includes a main body and an outer flange, wherein the outer flange is sleeved outside the middle part of the main body and connected to the main body; in the axial direction of the inner through hole, a reference groove is formed between the side of the outer flange away from the positioning groove and the outer wall of the main body, and the reference groove is coaxial with the second bearing chamber and the first bearing chamber.

[0012] In yet another implementation of the present disclosure, in the radial direction of the inner through hole, the distance between the outer groove wall of the reference groove and the inner circumferential wall of the second bearing chamber is no more than 1.5 mm.

[0013] In yet another implementation of the present disclosure, an inner diameter of the first bearing chamber is greater than an inner diameter of the second bearing chamber.

[0014] In another implementation of the present disclosure, the interior of the end cover also has a glue containing groove, which is located on the side of the second bearing chamber facing the first bearing chamber, and the inner diameter of the glue containing groove is larger than the inner diameter of the inner through hole and smaller than the inner diameter of the second bearing chamber.

[0015] In another implementation of the present disclosure, the outer rotor motor further includes a rotor, the rotor is sleeved outside the stator, and the rotor is connected to the motor shaft.

[0016] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0017] Since the outer wall of the end cover has a positioning groove, the stator is located in the positioning groove, and the stator and the end cover are riveted together. In this way, when the motor is manufactured, the stator part can be placed in the positioning groove in advance, and then the end cover is pressed into the inner through hole of the stator along the positioning groove, so that the stator is stuck in the positioning groove and pressed together with the end cover without separation, which further extends the service life of the outer rotor motor and makes the motor manufacturing more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of the structure of an outer rotor motor provided in an embodiment of the present disclosure;

[0020] Figure 2 for Figure 1 Structural schematic diagram of the middle end cover;

[0021] Figure 3 for Figure 1 Schematic diagram of the structure of the middle stator;

[0022] Figure 4 for Figure 1 Schematic diagram of the structure in which the middle stator and end cover are pressed together.

[0023] The symbols in the figure mean the following:

[0024] 1. End cover; 10. Inner through hole; 101. First bearing chamber; 102. Second bearing chamber; 103. Positioning groove; 120. Reference groove; 105. Glue groove; 11. Body; 12. External flange; 100. Riveting protrusion;

[0025] 2. Motor shaft;

[0026] 3. stator; 31. stator ring; 32. winding teeth; 33. limiting convex strip; 331. guide surface; 320. winding groove; 301. riveting groove;

[0027] 5. Rotor. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0029] The present disclosure provides an outer rotor motor, such as Figure 1 As shown, the outer rotor motor includes an end cover 1 , a motor shaft 2 and a stator 3 .

[0030] Figure 2 for Figure 1 The structural diagram of the middle end cover, combined with Figure 2The end cover 1 has an inner through hole 10, a first bearing chamber 101 and a second bearing chamber 102 inside, respectively. The first bearing chamber 101 and the second bearing chamber 102 are spaced apart at both ends of the inner through hole 10 along the axis of the inner through hole 10, and are both connected to the inner through hole 10. The outer wall of the end cover 1 has a positioning groove 103, and the positioning groove 103 extends from the first end of the end cover 1 toward the middle of the end cover 1. The first bearing chamber 101 is located at the first end of the end cover 1.

[0031] The middle part of the motor shaft 2 is located in the inner through hole 10 and connected to the end cover 1. The stator 3 is located in the positioning groove 103, and the stator 3 and the end cover 1 are riveted together.

[0032] Since the outer rotor motor provided by the embodiment of the present disclosure includes an end cover 1, a motor shaft 2 and a stator 3, wherein the interior of the end cover 1 has an inner through hole 10, a first bearing chamber 101 and a second bearing chamber 102, respectively, the middle part of the motor shaft 2 can be located in the inner through hole 10, and the bearings are accommodated by the first bearing chamber 101 and the second bearing chamber 102, so that the motor shaft 2 is rotatably connected to the end cover 1 through the bearings.

[0033] Since the outer wall of the end cover 1 has a positioning groove 103, the stator 3 is located in the positioning groove 103, and the stator 3 and the end cover 1 are riveted together. In this way, when the motor is manufactured, the stator 3 can be partially placed in the positioning groove 103 in advance, and then the end cover 1 is pressed into the inner hole of the stator 3 along the positioning groove 103, so that the stator 3 is stuck in the positioning groove 103 and pressed together with the end cover 1 without separation, which further extends the service life of the outer rotor motor and makes the motor manufacturing more environmentally friendly.

[0034] Optionally, the inner diameter of the first bearing chamber 101 is larger than the inner diameter of the second bearing chamber 102. This facilitates assembly, so that most bearings can meet the requirements.

[0035] Optionally, the positioning groove 103 is a tapered groove, and along the direction from the first bearing chamber 101 to the second bearing chamber 102 , the distance between the outer groove wall of the positioning groove 103 and the axis of the inner through hole 10 gradually decreases.

[0036] In the above implementation, the positioning groove 103 is set as a tapered groove, so that the stator 3 can be automatically guided when assembled on the end cover 1, which not only ensures the processability of the assembly, but also ensures the strength and accuracy of the assembly.

[0037] In other examples, the positioning groove 103 may also be other structures, such as a stepped groove, and correspondingly, the stator 3 is provided with a positioning step. The positioning step is clamped in the step. However, in this case, a positioning step and other structures need to be provided in the stator 3, which increases the difficulty of processing the stator 3.

[0038] Optionally, in the radial direction of the inner through hole 10 , the interval L between the inner peripheral wall of the first bearing chamber 101 and the outer groove wall of the positioning groove 103 is not greater than 1 mm.

[0039] In the above implementation, the interval L between the first bearing chamber 101 and the positioning groove 103 (that is, the wall thickness corresponding to the first bearing chamber 101) is not greater than 1 mm. In this way, while the first bearing chamber 101 can facilitate the installation of the bearing, the inner diameter of the inner hole of the stator 3 can be appropriately reduced to increase the winding space of the stator 3 and improve the performance of the outer rotor motor.

[0040] That is to say, the above can make full use of the wall thickness of the first bearing chamber 101 (the wall thickness in the relevant technology is at least 1.5 mm) to make the inner diameter of the first bearing chamber 101 larger than before, and the inner diameter of the stator 3 smaller than before, so that the bearing can be easily installed in the first bearing chamber 101 while the winding space of the stator 3 can be increased, thereby improving the performance of the outer rotor motor.

[0041] In this embodiment, the interval L between the first bearing chamber 101 and the positioning groove 103 (the distance from the outer groove wall of the positioning groove 103 to the central axis of the inner through hole 10 minus the inner diameter of the first bearing chamber 101) is less than 0.5 mm. L can even be a negative value. When L is a negative value, it means that the first bearing chamber is partially located on the stator 3.

[0042] Optionally, the end cover 1 has a first end and a second end, the first bearing chamber 101 is located at the first end, the second bearing chamber 102 is located at the second end, and the end cover 1 includes a columnar body 11 and an outer flange 12, the outer flange 12 is sleeved outside the middle part of the body 11 and connected to the body 11.

[0043] In the axial direction of the inner through hole 10 , a reference groove 120 is formed between the side of the outer flange 12 away from the positioning groove 103 and the outer wall of the body 11 . The reference groove 120 is coaxial with the second bearing chamber 102 and the first bearing chamber 101 .

[0044] In the above implementation, the end cover 1 is provided with a body 11 and an outer flange 12, so that the inner through hole 10, the first bearing chamber 101, the second bearing chamber 102, the positioning groove 103, etc. can be respectively provided on the body 11. At the same time, a reference groove 120 can be formed between the outer flange 12 and the body 11, and the first bearing chamber 101 and the second bearing chamber 102 can be further processed outside the inner through hole 10 with the central axis passing through the reference groove 120 as a reference, so that the first bearing chamber 101 and the second bearing chamber 102 are coaxial.

[0045] Moreover, since the end cover 1 and the stator 3 are riveted together, when processing the first bearing chamber 101 and the second bearing chamber 102, the end cover 1 can be riveted into the stator 3 in advance. Then the end cover 1 and the stator 3 are taken as an integral structure, and the first bearing chamber 101 and the second bearing chamber 102 are processed in the integral structure. In this way, since the stator 3 is pressed outside the end cover 1, the integral structure can be supported by the stator 3, so that the wall thickness of the first bearing chamber 101 is reduced, and then the inner diameter of the inner hole of the stator 3 is indirectly reduced.

[0046] In the related art, the two bearing chambers in the end cover are generally pre-processed, and then the end cover is assembled on the motor shaft through bearings, etc., and then the stator is sleeved outside the end cover, and finally the rotor is assembled on the motor shaft. In the outer rotor motor made in this way, the wall thickness corresponding to the bearing chamber in the end cover is generally thicker, because too thin will cause processing deformation, etc. When the wall thickness corresponding to the bearing chamber in the end cover is thicker, the inner diameter of the bearing chamber will be reduced or the inner hole of the stator will be increased, which will shorten the winding space of the stator and affect the performance of the motor.

[0047] That is to say, when processing the first bearing chamber 101 and the second bearing chamber 102, the end cover 1 can be firstly riveted into the stator 3, and then in the integral structure formed by the end cover 1 and the stator 3, the first bearing chamber 101 and the second bearing chamber 102 are directly milled out of the inner through hole 10 with the central axis of the reference groove 120 as a reference, so that the first bearing chamber 101 and the second bearing chamber 102 are coaxial, and the wall thickness of the first bearing chamber 101 is less than 1 mm.

[0048] In other examples, the inner hole and the first bearing chamber and the second bearing chamber with machining allowance may be pre-machined in the end cover, and then after the end cover is riveted into the stator, the first bearing chamber and the second bearing chamber may be further milled to increase the inner diameter of the first bearing chamber and the inner diameter of the second bearing chamber. As long as the wall thickness of the first bearing chamber 101 can be less than 1 mm, it will be sufficient.

[0049] Optionally, in the radial direction of the inner through hole 10, the distance between the outer groove wall of the reference groove 120 and the inner peripheral wall of the second bearing chamber 102 is not greater than 1.5 mm. This can further increase the inner hole of the second bearing chamber 102, so that the bearing can be installed in the second bearing chamber 102.

[0050] Combination Figure 1 and Figure 2 Optionally, the interior of the end cover 1 also has a glue groove 105, which is located on the side of the second bearing chamber 102 facing the first bearing chamber 101, and is respectively connected to the second bearing chamber 102 and the inner through hole 10, and the inner diameter of the glue groove 105 is larger than the inner diameter of the inner through hole 10, and smaller than the inner diameter of the second bearing chamber 102.

[0051] In the above implementation, the glue groove 105 is used to contain glue. When the bearing is installed in the second bearing chamber 102, the outer ring of the bearing and the inner circumferential wall of the second bearing chamber 102 can be bonded together by glue so that the two can be tightly fitted. When bonding by glue, generally a layer of glue is first brushed on the inner circumferential wall of the second bearing chamber 102, and then the bearing is placed in the second bearing chamber. In the process of the bearing moving into the second bearing chamber 102, the bearing will scrape off part of the glue, so that the glue scraped off by the bearing can be accommodated by the glue groove 105, so that after the glue is cured, the connection strength between the bearing and the second bearing chamber 102 can be further increased.

[0052] In other examples, the bearing assembly may not be performed by glue, for example, by directly fastening members, etc. However, since the end cover 1 is made of soft metal, the end cover 1 may be damaged when assembled by fastening members.

[0053] In addition, in this embodiment, the inner ring of the bearing located in the first bearing chamber 101 is interference fit with the motor shaft, and the outer ring of the bearing located in the first bearing chamber 101 is pressed into the first bearing chamber 101 by the rotor 5 (which will be introduced below). The inner ring of the bearing located in the first bearing chamber 101 is connected to the motor shaft through a retaining spring or the like. In this way, the bearing located in the first bearing chamber 101 is in a state of inner tightness and outer looseness, while the bearing located in the second bearing chamber 102 is in a state of inner looseness and outer tightness, which facilitates the installation of the bearing, and only one of the inner ring and outer ring of the bearing needs to be tight fit. The tight fit mentioned above refers to the implementation through fasteners or interference fit or the like.

[0054] Figure 3 for Figure 1 The structural diagram of the stator, combined with Figure 3 Optionally, the inner circumferential wall of the inner hole of the stator 3 has a plurality of riveting grooves 301 , and the plurality of riveting grooves 301 are circumferentially spaced apart and distributed on the inner circumferential wall of the inner hole of the stator 3 .

[0055] Figure 4 for Figure 1 Schematic diagram of the structure where the middle stator and the end cover are pressed together, combined with Figure 4 After the stator 3 and the end cover 1 are riveted together, the outer wall of the end cover 1 has a plurality of riveting protrusions 100, and the plurality of riveting protrusions 100 are circumferentially distributed on the outer groove wall of the positioning groove 103 with the axis of the inner through hole 10 as the axis interval, and the plurality of riveting protrusions 100 correspond one by one to the plurality of riveting grooves 301, and the riveting protrusions 100 are located in the corresponding riveting grooves 301.

[0056] In the above implementation, a rivet groove 301 is provided on the outer peripheral wall of the stator 3, and the end cover 1 can be accommodated through the rivet groove 301, so that when the end cover 1 is pressed into the stator 3, a rivet protrusion 100 is formed, so that the end cover 1 and the stator 3 are firmly assembled together by limiting the rivet protrusion 100 in the rivet groove 301.

[0057] In other examples, the end cover 1 and the stator 3 may be riveted in other ways, with multiple riveting pins, which are circumferentially distributed with the axis of the inner through hole 10 as the axis interval, and each riveting pin is respectively inserted into the corresponding grooves of the stator 3 and the end cover 1. However, arranging riveting pins separately will increase the cost and the assembly process.

[0058] In this embodiment, the riveting groove 301 is a semicircular groove, so that the end cover 1 can be extruded into a corresponding shape and riveted together with the stator 3.

[0059] Optionally, the end cover 1 is a soft metal structural member, so that when the end cover 1 is riveted into the stator 3 , it can be deformed to form a riveting protrusion 100 .

[0060] The soft metal mentioned above refers to a metal with good ductility. For example, the end cover 1 can be a copper structural member, an aluminum alloy structural member, a zinc alloy structural member, etc.

[0061] Optionally, the stator 3 includes a stator ring 31, a plurality of winding teeth 32 and a plurality of limiting convex strips 33, wherein the plurality of winding teeth 32 are evenly distributed on the outer periphery of the stator ring 31 with the central axis of the stator ring 31 as the axis, and each winding tooth 32 in the plurality of winding teeth 32 is arranged outward with the central axis of the stator ring 31 as the center, and the winding teeth 32 are connected to the stator ring 31. The plurality of limiting convex strips 33 are arranged one by one with the plurality of winding teeth 32. The limiting convex strips 33 are arc-shaped structures, and the center of the limiting convex strips 33 is located on the central axis of the stator ring 31. The inner arc surface of the limiting convex strips 33 is connected to the side of the corresponding winding tooth 32 away from the stator ring 31. The limiting convex strips 33 connected to two adjacent winding teeth 32 extend relative to each other. A winding groove 320 is formed between two adjacent winding teeth 32. For each limiting convex strip 33 , two sides of the limiting convex strip 33 have guide surfaces 331 , and along the radial inward direction of the stator ring 31 , the distance between the two opposite guide surfaces 331 gradually decreases.

[0062] The winding teeth 32 are used to connect with the stator ring 31 and provide winding space. The limiting convex strips 33 are used to limit the cables in the stator 3 in the winding grooves 320 to prevent the cables from escaping from the winding teeth 32. The guide surface 331 is used to guide the cables so that the cables can be inserted into the winding grooves 320.

[0063] See again Figure 1Optionally, the outer rotor motor further includes a rotor 5 , which is sleeved outside the stator 3 and connected to the motor shaft 2 .

[0064] The rotor is used to drive the motor shaft 2 to rotate synchronously so that the motor shaft 2 can output power.

[0065] The following briefly introduces the assembly process of the outer rotor motor provided by the embodiment of the present disclosure:

[0066] First, the end cover 1 with the inner through hole 10 is pressed into the stator 3, so that the outer peripheral wall of the end cover 1 forms a riveting protrusion 100, and the riveting protrusion 100 is located in the corresponding riveting groove 301, so that the end cover 1 and the stator 3 form an integral structure.

[0067] Then, taking the central axis of the reference groove 120 in the end cover 1 as a reference, the first bearing chamber 101 and the second bearing chamber 102 are respectively turned out outside the inner through hole 10 of the integral structure formed by the end cover 1 and the stator 3, and the wall thickness of the first bearing chamber 101 is made less than 1 mm.

[0068] Next, the cable is wound around the stator 3, and the motor shaft 2 with bearings and the rotor are mounted on the end cover 1, thereby completing the assembly of the outer rotor motor.

[0069] It can be seen that the wall thickness of the first bearing chamber 101 in the above outer rotor motor is thin, and the inner hole of the stator 3 is large, which increases the winding space of the stator 3, and the motor performance can be maximized within the allowable range. Moreover, when turning the first bearing chamber and the second bearing chamber, the stator 3 and the end cover 1 can be assembled together for processing first, which can fully ensure the coaxiality of the first bearing chamber and the second bearing chamber, and there will be no misalignment caused by material assembly. In addition, glue is no longer used in the assembly of the stator 3 and the end cover 1, which greatly increases environmental protection and reliability. Furthermore, the shaft diameter of the motor output shaft can be selected to be larger, so that the outer rotor motor can be suitable for large torque occasions.

[0070] The above are only optional embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. An outer rotor motor, characterized in that: The outer rotor motor comprises an end cover (1), a motor shaft (2) and a stator (3); The end cover (1) has an inner through hole (10), a first bearing chamber (101) and a second bearing chamber (102) therein; the first bearing chamber (101) and the second bearing chamber (102) are spaced apart at two ends of the inner through hole (10) along the axis of the inner through hole (10) and are both in communication with the inner through hole (10); the outer wall of the end cover (1) has an annular positioning groove (103); the positioning groove (103) extends from the first end of the end cover (1) toward the middle of the end cover (1); and the first bearing chamber (101) is located at the first end of the end cover (1); The middle portion of the motor shaft (2) is located in the inner through hole (10) and is rotatably connected to the end cover (1); The stator (3) is located in the positioning groove (103), and the stator (3) is riveted to the end cover (1).

2. The outer rotor motor according to claim 1, characterized in that: The inner peripheral wall of the inner hole of the stator (3) is provided with a plurality of riveting grooves (301), and the plurality of riveting grooves (301) are distributed at intervals in the circumferential direction on the inner peripheral wall of the inner hole of the stator (3); The outer wall of the end cover (1) has a plurality of riveted protrusions (100), and the plurality of riveted protrusions (100) are circumferentially distributed on the outer groove wall (1031) of the positioning groove (103) with the axis of the inner through hole (10) as the axis interval, and the plurality of riveted protrusions (100) correspond one-to-one to the plurality of riveted grooves (301), and the riveted protrusions (100) are located in the corresponding riveted grooves (301).

3. The outer rotor motor according to claim 2, characterized in that: The end cover (1) is a soft metal structural part.

4. The outer rotor motor according to any one of claims 1 to 3, characterized in that: The positioning groove (103) is a tapered groove, and along the direction from the first bearing chamber (101) to the second bearing chamber (102), the distance between the outer groove wall (1031) of the positioning groove (103) and the axis of the inner through hole (10) gradually increases.

5. The outer rotor motor according to any one of claims 1 to 3, characterized in that: In the radial direction of the inner through hole (10), the spacing between the inner peripheral wall of the first bearing chamber (101) and the outer groove wall (1031) of the positioning groove (103) is no greater than 1 mm.

6. The outer rotor motor according to any one of claims 1 to 3, characterized in that: The end cover (1) comprises a body (11) and an outer flange (12), wherein the outer flange (12) is sleeved outside the middle portion of the body (11) and is connected to the body (11); In the axial direction of the inner through hole (10), a reference groove (120) is formed between the side of the outer flange (12) away from the positioning groove (103) and the outer wall of the body (11), and the reference groove (120) is coaxial with the second bearing chamber (102) and the first bearing chamber (101).

7. The outer rotor motor according to claim 6, characterized in that: In the radial direction of the inner through hole (10), the distance between the outer groove wall of the reference groove (120) and the inner peripheral wall of the second bearing chamber (102) is no more than 1.5 mm.

8. The outer rotor motor according to any one of claims 1 to 3 and claim 7, characterized in that: The inner diameter of the first bearing chamber (101) is greater than the inner diameter of the second bearing chamber (102).

9. The outer rotor motor according to any one of claims 1 to 3 and claim 7, characterized in that: The end cover (1) further comprises a glue containing groove (105) inside, the glue containing groove (105) being located on the side of the second bearing chamber (102) facing the first bearing chamber (101), the inner diameter of the glue containing groove (105) being larger than the inner diameter of the inner through hole (10) and smaller than the inner diameter of the second bearing chamber (102).

10. The outer rotor motor according to any one of claims 1 to 3 and claim 7, characterized in that: The outer rotor motor further comprises a rotor (5), wherein the rotor (5) is sleeved outside the stator (3), and the rotor (5) is connected to the motor shaft (2).

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