CN222215331U

CN222215331U - Outer rotor motor

Info

Publication number: CN222215331U
Application number: CN202420684755.7U
Authority: CN
Inventors: 刘随强
Original assignee: Jiangsu Dongcheng Garden Machinery Co ltd
Current assignee: Jiangsu Dongcheng Garden Machinery Co ltd
Priority date: 2024-04-03
Filing date: 2024-04-03
Publication date: 2024-12-20
Anticipated expiration: 2034-04-03

Abstract

The outer rotor motor comprises a motor shaft extending along the axial direction, an outer rotor assembly for fixing the motor shaft and an inner stator assembly positioned between the motor shaft and the outer rotor assembly, wherein the inner stator assembly comprises an inner stator bracket sleeved on the periphery of the motor shaft and an inner stator iron core fixed on the inner stator bracket, the inner stator bracket comprises a base positioned at the axial front end of the inner stator iron core and a main body part extending backwards along the axial direction from the base, the inner stator assembly further comprises an insulating gasket sleeved on the periphery of the main body part, and the insulating gasket is positioned between the inner stator iron core and the base. The insulating gasket can separate the enameled wire of winding and the inner stator support in the axial direction, prevents the enameled wire from making electrical contact with the inner stator support, improves the insulating property of the outer rotor motor, and ensures that the outer rotor motor is safer and more reliable to use.

Description

Outer rotor motor

[ Technical field ]

The utility model relates to the technical field of external rotor motors, in particular to an external rotor motor with good insulation performance.

[ Background Art ]

Motors are generally classified into inner rotor motors and outer rotor motors according to the relative positions of the rotor and the stator, wherein the outer rotor motors are relatively space-saving and compact in design, and thus have been receiving attention. When the coil winding on the inner stator core is pressed on the inner stator bracket under the condition of higher slot filling rate during winding, the outgoing line and the bridge wire on the coil winding can be close to or even attached to the end face of the inner stator bracket, and at the moment, the problem that the outer rotor motor generates poor insulation and voltage resistance can be caused, so that the use of the outer rotor motor is influenced.

In view of the above, it is desirable to provide an improved external rotor motor that overcomes the shortcomings of the prior art.

[ Summary of the utility model ]

Aiming at the defects of the prior art, the utility model aims to provide an outer rotor motor which is provided with an insulation structure positioned between an inner stator bracket and a winding, and can effectively improve the insulation performance of the outer rotor motor.

The outer rotor motor comprises a motor shaft extending along the axial direction, an outer rotor assembly for fixing the motor shaft and an inner stator assembly arranged between the motor shaft and the outer rotor assembly, wherein the inner stator assembly comprises an inner stator bracket sleeved on the periphery of the motor shaft and an inner stator iron core fixed on the inner stator bracket, the inner stator bracket comprises a base arranged at the axial front end of the inner stator iron core and a main body part extending backwards along the axial direction from the base, and the inner stator assembly further comprises an insulating gasket sleeved on the periphery of the main body part, and the insulating gasket is arranged between the inner stator iron core and the base.

The insulation gasket comprises an outer ring positioned at the outer side, an inner ring positioned at the inner side and a plurality of bosses positioned at the inner ring, wherein the bosses are abutted against the peripheral wall of the main body part.

The diameter of the inner ring is larger than the outer diameter of the main body part, the inner diameter of the boss is smaller than the outer diameter of the main body part, and the inner ring is not contacted with the main body part.

The further improvement scheme is that the insulating gasket is made of insulating materials, and the thickness of the insulating gasket is 0.1mm to 2mm.

The inner stator assembly comprises an inner stator plastic-coated part sleeved on the inner stator iron core and a plurality of windings wound on the inner stator plastic-coated part.

The distance from the insulating gasket to the end face of the axial front end of the inner stator iron core is 5mm to 20mm.

The outer rotor assembly comprises an outer rotor shell for accommodating the inner stator assembly, the outer rotor shell is provided with an annular wall sleeved on the periphery of the inner stator core and an end wall positioned at the axial rear end of the annular wall, and the end wall is fixedly held on the motor shaft 1.

The outer rotor assembly comprises a plurality of magnetic steels attached to the inner wall of the annular wall, wherein the magnetic steels are located on the radial outer side of the inner stator core, and the magnetic steels are arranged around the inner stator core.

The outer rotor motor comprises a front bearing which is accommodated at the front end of the axial direction of the base, and the motor shaft is supported in the inner stator bracket through the front bearing.

The outer rotor motor comprises a rear bearing which is accommodated at the axial rear end of the inner stator core, the outer circumferential surface of the rear bearing is attached to the inner circumferential wall of the inner stator core, and the motor shaft is supported at the axial rear end of the inner stator core through the rear bearing.

Compared with the prior art, the utility model has the beneficial effects that the inner stator assembly also comprises the insulating gasket sleeved on the periphery of the main body part, and the insulating gasket is positioned between the inner stator iron core and the base. The insulating gasket can separate the enameled wire of winding and the inner stator support in the axial direction, prevents the enameled wire from making electrical contact with the inner stator support, improves the insulating property of the outer rotor motor, and ensures that the outer rotor motor is safer and more reliable to use.

[ Description of the drawings ]

The following describes the embodiments of the present utility model in further detail with reference to the accompanying drawings:

Fig. 1 is a perspective view of an external rotor motor of the present utility model;

FIG. 2 is a cross-sectional view of the outer rotor motor shown in FIG. 1;

FIG. 3 is an exploded view of the outer rotor motor shown in FIG. 2;

fig. 4 is a perspective view of an inner stator assembly of the outer rotor motor shown in fig. 1;

Fig. 5 is a perspective view of an inner stator bracket of the outer rotor motor shown in fig. 1;

FIG. 6 is a cross-sectional view of an inner stator bracket of the outer rotor motor shown in FIG. 5;

FIG. 7 is a perspective view of an outer rotor housing of the outer rotor motor shown in FIG. 1;

FIG. 8 is another angular perspective view of the outer rotor housing of the outer rotor motor of FIG. 7;

FIG. 9 is a cross-sectional view of an outer rotor housing and magnetic steel of the outer rotor motor shown in FIG. 8;

FIG. 10 is a perspective view of an outer rotor housing of the outer rotor motor shown in FIG. 1;

FIG. 11 is another angular perspective view of the outer rotor housing of the outer rotor motor of FIG. 10;

FIG. 12 is a cross-sectional view of an outer rotor housing and fan of the outer rotor motor shown in FIG. 1;

FIG. 13 is a perspective view of an insulating spacer of the outer rotor motor shown in FIG. 1;

fig. 14 is a perspective view of a motor shaft of the outer rotor motor shown in fig. 1.

Meaning of reference numerals in the drawings:

outer rotor motor 100 motor shaft 1

Front bearing 10 spacer 101

Rear bearing 11 of snap spring 102

First joint 12 outer rotor assembly 2

Annular wall 201 of outer rotor housing 20

Magnetic steel groove 2010 accommodating groove 2011

Air inlet 2020 in end wall 202

First extension 203 and second extension 204

Second coupling portion 2040 and first fitting portion 2041

Extension 205 inner stator assembly 3

Inner stator support 30 base 301

Body 302 supporting portion 303

Step 304 annular sleeve 31

Insulating spacer 32 outer ring 321

Boss 323 of inner race 322

Inner stator core 33 windings 34

Second fitting portion 40 of fan 4

Radial width D1 of magnetic steel groove and radial width D2 of accommodating groove

Radial depth D3 of magnetic steel groove and radial depth D4 of accommodating groove

Detailed description of the preferred embodiments

The terminology used in the present utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. Words such as "upper", "lower", "front", "rear", etc., indicating an azimuth or a positional relationship are based on only the azimuth or the positional relationship shown in the drawings, and are merely for convenience of description and to simplify the description, and do not indicate or imply that the apparatus/elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present utility model.

Referring to fig. 1 to 14, an external rotor motor 100 according to the present utility model is generally used for connecting to an electric tool, and the external rotor motor 100 has the characteristics of convenient operation and maintenance, simple and feasible assembly, compact structure, reliable operation, environmental protection, economy, etc. The outer rotor motor 100 comprises a motor shaft 1 extending along the axial direction, an outer rotor assembly 2 connected with the motor shaft 1 and an inner stator assembly 3 positioned between the motor shaft 1 and the outer rotor assembly 2, wherein the motor shaft 1 rotates along with the outer rotor assembly 2 relative to the inner stator assembly 3.

Referring to fig. 1 to 3, the outer rotor assembly 2 has an outer rotor housing 20 for accommodating the inner stator assembly 3, the outer rotor housing 20 includes an annular wall 201 sleeved on the outer periphery of the inner stator assembly 3 and an end wall 202 located at the axial rear side of the annular wall 201, the annular wall 201 extends from the circumferential side of the end wall 202 forward in the axial direction, and the motor shaft 1 is disposed through the end wall 202.

The outer rotor housing 20 may be cylindrical, and has an outer diameter larger than that of the inner stator assembly 3, and one end of the outer rotor housing 20 is open for the inner stator assembly 3 to penetrate. In the present embodiment, the outer rotor housing 20 is formed of a metal material, and it will be appreciated that in other alternative embodiments, the outer rotor housing 20 may be formed of other materials.

As shown in fig. 9, the outer rotor housing 20 further includes an extension 205 protruding from the end wall 202 toward both axial ends, and the extension 205 includes a first extension 203 located at the axial front end of the end wall 202 and a second extension 204 located at the axial rear end of the end wall 202.

The annular wall 201, the end wall 202, the first extension portion 203 and the second extension portion 204 are integrally formed by a cold heading process, and after the cold heading process is performed on the outer rotor casing 20, each portion may be further processed by a finish machining mode, for example, the axial length, the wall thickness, etc. of the first extension portion 203 and the second extension portion 204 are changed by cutting.

In the conventional solution, the outer rotor casing 20 is integrally formed by a stamping process, and due to the characteristics of the stamping parts, on one hand, the wall thickness of the end wall 202 and the wall thickness of the first extension portion 203 are the same, and on the other hand, the stamping process cannot form the first extension portion 203 and the second extension portion 204 at the two axial ends of the end wall 202, and generally only the first extension portion 203 located at the axial front end of the end wall 202 is formed. After the motor shaft 1 is assembled with the end wall 202 and the first extension 203, a joint between the motor shaft 1 and the outer rotor casing 20 may be broken during the use of the outer rotor motor 100, so that the outer rotor motor 100 may fail and be damaged.

In this embodiment, during cold heading forming of the outer rotor casing 20, the first extension portion 203 and the second extension portion 204 are integrally formed at two axial ends of the end wall 202, and after the motor shaft 1 is assembled with the first extension portion 203, the end wall 202 and the second extension portion 204, the bonding force at the joint between the motor shaft 1 and the outer rotor casing 20 and the dimensional accuracy after press-fitting can be improved, and the strength of the outer rotor casing 20 during rotation can be improved.

Referring to fig. 3, the outer diameter of the motor shaft 1 is larger than the inner diameter of the first extension 203, and the outer circumferential surface of the motor shaft 1 is mounted on the inner circumferential surface of the first extension 203 in an interference fit manner.

Further, as shown in fig. 7 and 14, the inner wall of the second extension portion 204 includes a plurality of second coupling portions 2040, the axial rear end of the motor shaft 1 includes a plurality of first coupling portions 12, the first coupling portions 12 are the same as the second coupling portions 2040 in number and are adapted in shape, the outer peripheral surfaces of the first coupling portions 12 are cooperatively mounted on the inner peripheral surfaces of the second coupling portions 2040, the outer diameter of the first coupling portions 12 is larger than the inner diameter of the second coupling portions 2040, and the motor shaft 1 is mounted in the second coupling portions 2040 of the second extension portion 204 through the first coupling portions 12 in a small interference fit or excessive fit.

The first coupling portion 12 and the second coupling portion 2040 may further increase the coupling force between the motor shaft 1 and the outer rotor casing 20, so that the motor shaft 1 and the outer rotor casing 20 are prevented from sliding relatively during the operation of the outer rotor motor 100. In the present embodiment, the first coupling portion 12 is configured as a protrusion, the second coupling portion 2040 is configured as a recess, alternatively, the first coupling portion 12 may be configured as a recess, and the second coupling portion 2040 may be configured as a protrusion, and the shapes of the first coupling portion 12 and the second coupling portion 2040 may be selected according to the requirements, for example, the protrusion may be configured as a trapezoid, a semi-cylinder, a triangle, or the like. Preferably, the number of the first coupling parts 12 and the second coupling parts 2040 is at least 3, so that the possibility of relative sliding between the two parts can be reduced.

Providing a chamfer at the junction of the first extension 203 and the end wall 202 may further increase the strength of the outer rotor casing 20, reducing the likelihood of fracture between the first extension 203 and the end wall 202.

Since the outer rotor casing 20 is integrally formed by a cold heading process, the dimensions of the first extension portion 203 and the second extension portion 204 may be freely selected by a finish machining manner, so that the wall thickness of the first extension portion 203 and the second extension portion 204 may be made larger than the wall thickness of the end wall 202, and the strength of the outer rotor casing 20 may be further improved. Preferably, the wall thickness of the second extension 204 is not less than 2mm, which can provide better strength between the second extension 204 and the end wall 202 without breaking the second extension 204.

Referring to fig. 7, 9 and 12, the outer rotor housing 20 holds a fan 4 thereon, and the fan 4 is integrally injection molded onto the outer rotor housing 20. Specifically, after finishing the outer rotor housing 20, the fan 4 is integrally injection molded on the second extension 204. The fan 4 rotates together with the outer rotor casing 20.

In the conventional solution, the fan 4 is fixed at the axial rear end of the motor shaft 1, and the fan 4 and the motor shaft 1 are assembled by interference fit, and in order to reduce the possibility of sliding between the fan 4 and the motor shaft 1, knurling is required to be added on the outer circumferential surface of the motor shaft 1 or an insert is required to be added at the central hole of the inner ring of the fan 4 during injection molding, so that the assembly method has more parts and complex process.

In this embodiment, after the outer rotor casing 20 is cold-headed and formed, the outer rotor casing is placed in a jig, and the fan 4 is directly formed on the second extension portion 204 by injection molding, so that the production process can be reduced, the production efficiency can be improved, and the balance between the fan 4 and the second extension portion 204 can be improved by integral molding. The fan 4 may be injection molded from a plastic material, or injection molded from another metal material such as aluminum.

Further, a first fitting portion 2041 is provided on the outer periphery of the second extension portion 204, a second fitting portion 40 is provided on the inner periphery of the fan 4, the second fitting portion 40 is adapted to the shape of the first fitting portion 2041, and the second fitting portion 40 and the first fitting portion are fitted to each other.

In this embodiment, the first fitting portion 2041 is configured as an annular groove, and the second fitting portion 40 is configured as an annular protrusion, which are mutually fitted, so that the fan 4 does not axially move or fall off due to vibration during rotation.

Considering that the second extension 204 needs to be provided with the first mating portion 2040 and needs to be injection molded with the fan 4, the axial length of the second extension 204 is not less than 4mm, the thickness of the fan 4 may be selected according to design requirements, and the axial rear end surface of the fan 4 may protrude out of the axial rear end surface of the second extension 204, or the axial rear end surface of the fan 4 is flush with the axial rear end surface of the second extension 204, or the axial rear end surface of the fan 4 is shorter than the axial rear end surface of the second extension 204.

In order to ensure the binding force between the first fitting portion 2041 and the second fitting portion 40, the axial length of the first fitting portion 2041 is not less than 2mm, and the radial depth of the first fitting portion 2041 is not less than 1mm. When the axial length and the radial depth of the first fitting portion 2041 are too small, the axial positioning effect on the fan 4 is poor, and the fan 4 may axially float or even fall on the second extension portion 204.

Referring to fig. 8, the end wall 202 is provided with a plurality of air outlets 2020 penetrating the end wall 202, the air outlets 2020 are located at the axial front end of the fan 4, and the fan 4 is disposed adjacent to the air outlets 2020. In this embodiment, the fan 4 is a centrifugal fan, the blades of the fan 4 are disposed towards the air outlet 2020, and the fan 4 may suck in external air from the axial front end of the outer rotor motor 100 and discharge the external air from the axial rear end, so as to achieve the purpose of cooling the outer rotor motor 100.

The air outlet 2020 is configured to exhaust cooling air entering the outer rotor motor 100, after the outer rotor motor 100 is started, the outer rotor housing 20 rotates and drives the fan 4 to rotate, and due to the characteristics of the centrifugal fan, external air enters from the axial front end of the outer rotor motor 100, and after flowing through the inner stator assembly 3, the external air cools and dissipates heat of the inner stator assembly 3, and is exhausted from the air outlet 2020.

In this embodiment, the number of the air outlets 2020 is 6, the air outlets 2020 are circular and are arranged around the center of the end wall 202, so that not only the air volume of the cooling air is ensured, but also the appearance is attractive, preferably, the number of the air outlets 2020 can be one or more, and the shape can be any shape or a combination of different shapes.

The fan 4 is not required to be assembled in a press-fit manner, so that the length of the fan 4 away from the end wall 202 can be selected according to design requirements, and preferably, the fan 4 is attached to the end surface of the end wall 202, so that the air quantity of cooling air entering the outer rotor motor 100 can be increased, a better heat dissipation effect is achieved, and meanwhile, the axial size can be reduced, so that the outer rotor motor 100 is compact.

In another embodiment, the fan 4 is integrally injection molded to the first extension 203, and the first engaging portion 2041 is provided on the first extension 203, so as to prevent the fan 4 from axially moving on the first extension 203. In this case, an axial fan is used for the fan 4 in order to cool the external rotor motor 100.

Referring to fig. 4 to 5, the inner stator assembly 3 includes an inner stator bracket 30 sleeved on the outer circumference of the motor shaft 1, an inner stator core 33 fixed on the inner stator bracket 30, and a plurality of windings 34 wound on the inner stator core 33. The inner stator core 33 has a cylindrical hollow structure with two ends penetrating, and is made by punching a plurality of sheet-shaped steel sheets. An inner stator plastic coating member (not shown) is arranged between tooth grooves (not shown) of the inner stator iron core 33, and the inner stator plastic coating member can separate different teeth to play an insulating role. The winding 34 is wound on the tooth part of the inner stator core 33 through the inner stator plastic coating, the winding 34 is correspondingly arranged with the tooth part, the windings 34 can be multiple groups, and the winding 34 can generate electromagnetic induction in the electrified state.

When winding the windings 34, each stator core 33 may be wound independently by using a winding machine in a flying fork manner, and after the winding is completed, the wire ends are welded, so that the operation is simple, the operation is easy, and a higher slot filling rate can be realized.

Further, the motor shaft 1 may have a cylindrical shape with a length greater than that of the inner stator assembly 3. One end of the motor shaft 1 is penetrated from the inner stator bracket 30 and rotatably connected to the inner stator bracket 30, and the other end of the motor shaft 1 is penetrated from the second extension 204 and rotatably connected to the outer rotor housing 20.

The inner stator holder 30 includes a base 301 at an axial front end of the inner stator core 33, a body portion 302 extending axially rearward from the base 301, and a supporting portion 303 extending axially rearward from the body portion 302, an outer diameter of the body portion 302 being different from an outer diameter of the supporting portion 303, and the inner stator holder 30 is integrally injection-molded by aluminum metal.

The outer circumference of the supporting portion 303 is sleeved with an annular sleeve 31, and the inner circumferential wall of the inner stator core 33 is fitted to the outer circumferential surface of the annular sleeve 31. The material of the annular sleeve 31 is the same as that of the inner stator core 33, specifically, the annular sleeve 31 is made of steel, and the hardness of the annular sleeve 31 is greater than that of the supporting portion 303.

In this embodiment, after the inner stator support 30 is rough machined, the annular sleeve 31 is press-fitted to the outer periphery of the supporting portion 303, the outer diameter of the supporting portion 303 is larger than the inner diameter of the annular sleeve 31, and due to the difference of materials of the two, the annular sleeve 31 cuts the supporting portion 303 and generates aluminum scraps in the press-fitting process, and after the press-fitting is completed, the aluminum scraps can be removed, and meanwhile, the inner stator support 30 after the press-fitting of the annular sleeve 31 is finished, so that the required size is obtained, and the accuracy requirement is met to the greatest extent.

In the conventional assembly scheme, the inner circumferential wall of the inner stator core 33 is directly mounted in cooperation with the outer circumferential surface of the supporting portion 303, the inner diameter of the inner stator core 33 is smaller than the outer diameter of the supporting portion 303, and the outer circumferential surface of the supporting portion 303 made of steel is cut by the inner stator core 33 made of aluminum during the mounting process, so that aluminum scraps are generated and fall into the outer rotor motor 100, and the aluminum scraps affect the outer rotor motor 100 and other parts in the outer rotor motor 100 and even cause failure. In the prior art, a chip storage groove is formed on the outer circumferential surface of the supporting portion 303, and at this time, aluminum chips generated by cutting are accumulated in the chip storage groove, however, when the aluminum chips are too much, the steel sheet of the stator core 33 is extruded and deformed, and the aluminum chips can fall out from the press-fit spigot surface of the inner stator bracket 30 into the outer rotor motor 100, thereby causing problems of poor insulation and voltage resistance, increased noise and even failure. The other improvement scheme is that the inner stator bracket 30 is subjected to cold storage treatment and then is subjected to press mounting, so that cutting aluminum scraps can be avoided, but liquid helium is adopted in the cold storage technology in the market at present, and the scheme has certain potential safety hazard and is high in cost.

In this embodiment, after the annular sleeve 303 is sleeved on the outer periphery of the supporting portion 303, the inner stator core 33 is pressed onto the annular sleeve 31, the inner diameter of the inner stator core 33 is smaller than the outer diameter of the annular sleeve 31, and the inner stator core 33 is mounted onto the annular sleeve 31 in an interference fit manner, so that a high bonding force between the inner stator core and the annular sleeve can be ensured. The annular sleeve 31 and the inner stator core 33 are made of the same material, so that the two materials have similar properties, for example, steel materials are used for manufacturing and forming, so that cutting waste is not generated during press fitting, meanwhile, the possibility of relative sliding can be greatly reduced or even avoided due to stable binding force between the two materials, and the safety of the outer rotor motor 100 in the running process is ensured.

Alternatively, the annular sleeve 31 may be formed of various materials, the outer peripheral wall of the annular sleeve 31 contacting the inner peripheral wall of the inner stator core 33 is formed of steel, and the inner peripheral wall of the annular sleeve 31 contacting the outer peripheral wall of the supporting portion 303 is formed of other materials, such as plastic, metal, etc.

The axial length of the annular sleeve 31 is not greater than the axial length of the inner stator core 33, and the combined part of the two needs to keep a certain matching length so as to meet the matching force requirement of the two.

A step 304 is provided at the junction of the main body 302 and the support 303, the end of the annular sleeve 31 abuts against the step 304, and the step 304 can provide axial positioning when the annular sleeve 31 is press-fitted to the support 303.

After the inner stator core 33 is press-fitted to the inner stator support 30, when the full rate of the winding groove of the inner stator core 33 is high, the outgoing line and the bridge wire on the winding 34 may approach to or even adhere to the inner stator support 30 in the axial direction, although the outer layer of the enameled wire of the winding 34 has a layer of insulating paint, the situation that the insulating paint is scratched may occur, and at this moment, after the damaged enameled wire contacts the inner stator support 30 made of metal, the situation that the outer rotor motor 100 has poor insulation and voltage resistance and even fails may occur.

As shown in fig. 4, 6 and 13, the inner stator assembly 3 includes an insulating spacer 32 sleeved on the outer periphery of the main body 302, and the insulating spacer 32 is located between the inner stator core 33 and the base 301. Preferably, the insulating spacer 32 is disposed adjacent to the base 301, and the insulating spacer 32 may be attached to an end surface of the base 301. The insulating spacer 32 is made of an insulating material, and the insulating spacer 32 can axially separate the enamel wire of the winding 34 from the inner stator support 30, so as to prevent the enamel wire from making electrical contact with the inner stator support 30.

Further, the insulating spacer 32 is in a ring shape, the insulating spacer 32 includes an outer ring 321 located at the outer side, an inner ring 322 located at the inner side, and a plurality of bosses 323 located on the inner ring 322, and the bosses 323 may be in a semicircular shape, a semi-trapezoid shape, or the like. The diameter of the inner ring 322 is larger than the outer diameter of the main body 302, the inner diameter of the boss 323 is smaller than the outer diameter of the main body 302, the insulating spacer 32 is clamped on the outer periphery of the main body 302 through the boss 323, and the inner ring 322 is not in contact with the main body 302.

The insulating spacer 32 is made of a soft material and has a certain rebound resilience, so that when the insulating spacer 32 is clamped on the main body 302 by the boss 323, a certain binding force between the insulating spacer 32 and the main body can be ensured, and the insulating spacer 32 cannot deform excessively.

The thickness of the insulating spacer 32 may be selected according to design requirements, for example, a proper size is selected according to a distance between the inner stator core 33 and the inner stator frame 30 after the inner stator core is mounted, alternatively, the thickness of the insulating spacer 32 is 0.1mm to 2mm, and in addition, when the outer rotor motor 100 is a high voltage motor, the thickness of the insulating spacer 32 needs to be increased accordingly. After the assembly of the inner stator core 33 is completed, the distance between the end surface of the axial front end of the inner stator core and the insulation spacer 32 is approximately 5mm to 20mm, the enameled wire of the winding 34 may approach or touch the insulation spacer 32, and at this time, the insulation spacer 32 made of an insulation material may realize the axial insulation between the winding 34 and the inner stator support 30, thereby improving the insulation performance of the outer rotor motor 100 and making the use thereof safer and more reliable.

Referring to fig. 9 to 11, the outer rotor assembly 2 includes a plurality of magnetic steels 21 attached to an inner wall of the outer rotor housing 20, the magnetic steels 21 are disposed around the inner stator core 33, the outer rotor housing 20 further includes a plurality of magnetic steel grooves 2010 concavely disposed on an inner wall of the annular wall 201, and each of the magnetic steels 21 is accommodated in the magnetic steel groove 2010. The magnetic steel 21 is matched with the inner stator assembly 3 through electromagnetic induction, and converts electric energy into mechanical energy, so that the magnetic steel rotates and drives the outer rotor shell 20 to rotate, and further drives the motor shaft 1 to rotate.

Further, the magnetic steel 21 is one of alnico magnetic steel, ferrite magnetic steel and neodymium-iron-boron magnetic steel. Of course, the types of the magnetic steel 21 are not limited to the above three types, and those skilled in the art can choose other types of the magnetic steel 21 according to actual situations and needs.

In this embodiment, the shape of the magnetic steel 21 is square, the square magnetic steel 21 can control the outer rotor motor 100 more smoothly, and the square is more convenient to process, alternatively, the magnetic steel 21 can be in any shape such as tile, arc, etc., and the number of the magnetic steel 21 is selected according to the design requirement of the outer rotor motor 100, for example, 6, 8, 12, even fewer or more.

In the conventional assembly scheme, a plastic bracket needs to be placed inside the outer rotor casing 20, specifically, the plastic bracket is attached to the inner wall of the annular wall 201, the plastic bracket is provided with grooves spaced apart from each other, the magnetic steel 21 is inserted into the grooves of the plastic bracket after the plastic bracket is placed at the bottom of the outer rotor casing 20, and the back surface of the magnetic steel 21 is subjected to glue brushing treatment, so that the magnetic steel 21 can be more firmly attached to the inner wall of the annular wall 201. However, in this solution, the positioning of the plastic bracket to the magnetic steel 21 is not reliable enough, and the plastic bracket needs to be put into the outer rotor casing 20 first, so that the installation process is complex and the efficiency is low.

In this embodiment, after the outer rotor casing 20 is cold-headed and formed, the magnetic steel groove 2010 is formed on the inner wall of the annular wall 201 by a finish machining method, and the magnetic steel 21 can be directly placed in the magnetic steel groove 2010 without additionally providing a plastic bracket. Because the shape of the magnetic steel groove 2010 is adapted to the shape of the magnetic steel 21, after the magnetic steel 21 is placed in the magnetic steel groove 2010, at least a part of the inner wall of the magnetic steel groove 2010 is abutted against the outer wall of the magnetic steel 21, so that better positioning of the magnetic steel 21 can be provided, and the magnetic steel 21 can be more firmly fixed on the inner wall of the magnetic steel groove 2010 after installation is completed. By adopting the scheme, the technical process can be reduced, the assembly efficiency is improved, the production cost is reduced, and the magnetic steel 21 is more reliably fixed in the outer rotor shell 20.

Further, in order to improve the fixing effect of the magnetic steel 21, it is further necessary to use a glue to fix the magnetic steel 21, where the glue may be glue, and the glue may attach the magnetic steel 21 to the magnetic steel groove 2010 more firmly. When the magnetic steel 21 is glued and then placed in the magnetic steel groove 2010, part of glue leaks from the outer peripheral wall of the magnetic steel groove 2010, and the magnetic steel 21 protrudes out of the magnetic steel groove 2010 along a radial direction, which affects the operation of the outer rotor motor 100.

For this purpose, each annular wall 201 is provided with a receiving groove 2011 radially recessed from the bottom of the magnetic steel groove 2010, the receiving groove 2011 is located radially outside the magnetic steel groove 2010, and the magnetic steel groove 2010 and the receiving groove 2011 are formed on the inner wall of the annular wall 201 after the outer rotor housing 20 is cold-headed. After the side of the magnetic steel 21 is glued and placed in the magnetic steel groove 2010, part of the glue flows into the accommodating groove 2011, so that the glue does not flow out from the periphery of the magnetic steel groove 2010, and the operation of the outer rotor motor 100 is not affected.

Specifically, the axial length of the accommodating groove 2011 is not greater than the axial length of the magnetic steel groove 2010, the radial width D2 of the accommodating groove 2011 is not less than 60% of the radial width D1 of the magnetic steel groove 2010, the wall thickness of the annular wall 201 is at least 1.5mm greater than the radial depth D3 of the magnetic steel groove 2010, and the radial depth D4 of the accommodating groove is 0.1mm to 0.5mm. The shape and size of the magnetic steel groove 2010 are adapted to those of the magnetic steel 21, so that the magnetic steel 21 can be better fixed on the annular wall 201, the accommodating groove 2011 can accommodate the glue on the magnetic steel 21, so that the glue cannot overflow from the side edge of the magnetic steel groove 2010, and the magnetic steel groove 2010 and the accommodating groove 2011 are designed in size, so that the annular wall 201 has enough strength.

Referring to fig. 3 and 4, the external rotor motor 100 is provided with a front bearing 10 and a rear bearing 11 at both axial ends of the motor shaft 1. The front bearing 10 is received in an axial front end of the inner stator bracket 30, and the motor shaft 1 is supported in the inner stator bracket 30 through the front bearing 10. The rear bearing 11 is located at an axial rear end of the inner stator core 33, and further, the rear bearing 11 is located in the through hole of the inner stator core 33 such that the motor shaft 1 is supported in the inner stator core 33 through the rear bearing 11.

The radial dimension of the front bearing 10 may be larger than the radial dimension of the rear bearing 11, and the outer diameter dimension of the rear bearing 11 may be adapted to the inner diameter dimension of the inner stator core 33. The rear bearing 11 is disposed in the inner stator core 33, so that the mold-opening cost for installing the bearing chamber of the rear bearing 11 can be omitted, thereby simplifying the process and saving the production cost.

Further, the outer rotor motor 100 further includes a clamping spring 102 disposed at the front end of the motor shaft 1 in the axial direction, the clamping spring 102 may be clamped on the motor shaft 1, and the clamping spring 102 is located on a section of the motor shaft 1 penetrating out of the inner stator support 30. Specifically, the clamping spring 102 is arranged close to the front bearing 10 to prevent the front bearing 10 from falling out, and a gasket 101 is further arranged between the front bearing 10 and the clamping spring 102, wherein the gasket 101 can be used for preventing the front bearing 10 and the clamping spring 102 from rubbing against each other to cause abrasion.

Referring to fig. 2, the rear bearing 11 is located at the axial front end of the first extension 203, the end of the first extension 203 abuts against the end surface of the rear bearing 11, the first extension 203 can provide axial positioning for the rear bearing 11, and the first extension 203 can be machined according to the installation position of the rear bearing 11 to obtain the required positioning size. By the arrangement, the motor shaft 1 is prevented from being arranged in a stepped shape, the rear bearing 11 is limited by the stepped part of the motor shaft 1, the processing technology of the motor shaft 1 can be simplified, and the manufacturing cost is reduced.

In the present embodiment, the inner stator assembly 3 further includes an insulating spacer 32 fitted around the outer periphery of the main body 302, and the insulating spacer 32 is located between the inner stator core 33 and the base 301. The insulating spacer 32 can axially separate the enameled wire of the winding 34 from the inner stator support 30, so that the enameled wire is prevented from being in electrical contact with the inner stator support 30, the insulating performance of the outer rotor motor 100 is improved, and the outer rotor motor is safer and more reliable to use.

The present utility model is not limited to the above-described embodiments. Those of ordinary skill in the art will readily appreciate that many alternatives to the outer rotor motor of the present utility model are possible without departing from the spirit and scope of the present utility model. The protection scope of the present utility model is subject to the claims.

Claims

1. The outer rotor motor comprises a motor shaft extending along the axial direction, an outer rotor assembly for fixing the motor shaft and an inner stator assembly arranged between the motor shaft and the outer rotor assembly, wherein the inner stator assembly comprises an inner stator bracket sleeved on the periphery of the motor shaft and an inner stator iron core fixed on the inner stator bracket, the inner stator bracket comprises a base arranged at the axial front end of the inner stator iron core and a main body part extending backwards from the base along the axial direction, and the outer rotor motor is characterized by further comprising an insulating gasket sleeved on the periphery of the main body part, and the insulating gasket is arranged between the inner stator iron core and the base.

2. The external rotor motor according to claim 1, wherein the insulating spacer comprises an outer ring positioned at the outer side, an inner ring positioned at the inner side and a plurality of bosses positioned at the inner ring, and the bosses are abutted against the outer peripheral wall of the main body.

3. The external rotor motor according to claim 2, wherein the diameter of the inner ring is larger than the outer diameter of the main body portion, the inner diameter of the boss is smaller than the outer diameter of the main body portion, and the inner ring is not in contact with the main body portion.

4. The external rotor motor according to claim 3, wherein the insulating spacer is made of an insulating material, and the thickness of the insulating spacer is 0.1mm to 2mm.

5. The outer rotor motor of claim 4, wherein the inner stator assembly comprises an inner stator plastic-coated part sleeved on the inner stator iron core and a plurality of windings wound on the inner stator plastic-coated part.

6. The external rotor motor according to claim 5, wherein a distance from the insulating spacer to an end face of an axial front end of the inner stator core is 5mm to 20mm.

7. The external rotor motor according to claim 1, wherein the external rotor assembly comprises an external rotor housing accommodating the internal stator assembly, the external rotor housing is provided with an annular wall sleeved on the periphery of the internal stator core and an end wall positioned at the axial rear end of the annular wall, and the end wall is fixedly held on the motor shaft (1).

8. The external rotor motor of claim 7, wherein the external rotor assembly comprises a plurality of magnetic steels attached to an inner wall of the annular wall, the magnetic steels being located radially outside the internal stator core, the magnetic steels being disposed around the internal stator core.

9. The external rotor motor according to claim 1, wherein the external rotor motor includes a front bearing received in an axial front end of the base, and the motor shaft is supported in the inner stator bracket through the front bearing.

10. The external rotor motor according to claim 1, wherein the external rotor motor includes a rear bearing received at an axial rear end of the inner stator core, an outer circumferential surface of the rear bearing is fitted to an inner circumferential wall of the inner stator core, and the motor shaft is supported at the axial rear end of the inner stator core through the rear bearing.