CN217486244U

CN217486244U - Outer rotor brushless motor

Info

Publication number: CN217486244U
Application number: CN202220712104.5U
Authority: CN
Inventors: 孙宇龙; 张扣锅
Original assignee: Jiangsu Dongcheng Tools Technology Co Ltd
Current assignee: Jiangsu Dongcheng Tools Technology Co Ltd
Priority date: 2022-03-30
Filing date: 2022-03-30
Publication date: 2022-09-23
Anticipated expiration: 2032-03-30

Abstract

An outer rotor brushless motor comprises a rotating shaft extending along the axial direction, an outer rotor assembly connected to the rotating shaft, an inner stator assembly located between the rotating shaft and the outer rotor assembly and a fan fixed on the rotating shaft, wherein the outer rotor assembly comprises a shell with one axial end fixed on the rotating shaft, the shell is provided with an accommodating cavity and an opening located at one axial end and communicated with the accommodating cavity, the inner stator assembly comprises a rack sleeved on the outer side of the rotating shaft, a rack part is accommodated in the accommodating cavity, the fan is located in the shell and is arranged close to the opening, the fan rotates along with the rotating shaft to generate air flow, the inner stator assembly is provided with a plurality of heat dissipation channels located on the side wall of the rack, the heat dissipation channels are provided with air inlets located on the axial end face of the rack and air outlets located on the annular wall face of the rack, the air inlets are close to the fan, and the air outlets are exposed out of the shell. Compared with the existing water cooling method in the market, the method is safer, safe and reliable in operation, convenient to operate and maintain, simple and feasible in assembly, more environment-friendly and economical, and suitable for batch production.

Description

Outer rotor brushless motor

[ technical field ] A method for producing a semiconductor device

The utility model relates to a brushless motor technical field, in particular to good external rotor brushless motor of radiating effect.

[ background of the invention ]

The outer rotor brushless motor is widely used in various fields such as an electric chain saw, a blower, a grass trimmer, etc. because of its high power density and small size. An external rotor brushless motor in an electric chain saw, a blower, and a grass trimmer generally includes an inner stator installed in a housing of the electric chain saw, the blower, and the grass trimmer and having a stator winding, and an external rotor having a body surrounding the outer circumference of the inner stator and having magnetic poles. The traditional inner stator mainly comprises a steel sheet iron core, an insulating wire frame, a winding coil and the like, wherein the coil is wound on teeth of the inner stator, and the winding mode generally adopts concentrated winding. However, in the case of high rotation speed, the core loss of the inner stator accounts for a considerable proportion of the no-load and load conditions, thereby affecting the working efficiency of the outer rotor brushless motor. Meanwhile, the outer rotor brushless motor has the problem of difficult stator heat dissipation, and needs good heat dissipation conditions when dealing with high-power loads.

Therefore, it is necessary to provide a novel external rotor brushless motor, which improves the heat dissipation problem of the motor and increases the endurance of the electric tool.

[ Utility model ] content

To prior art not enough, the utility model aims to provide a high-efficient radiating external rotor brushless motor, under high rotating speed's operating mode, can effectively solve the motor heat dissipation problem under the high load.

The utility model provides a prior art problem can adopt following technical scheme: an outer rotor brushless motor comprises a rotating shaft extending along an axial direction, an outer rotor assembly connected to the rotating shaft, an inner stator assembly located between the rotating shaft and the outer rotor assembly, and a fan fixed on the rotating shaft, wherein the outer rotor assembly comprises a shell with one axial end fixed on the rotating shaft, the shell is provided with an accommodating cavity and an opening located at one axial end and communicated with the accommodating cavity, the inner stator assembly comprises a rack sleeved on the outer side of the rotating shaft, part of the rack is accommodated in the accommodating cavity, the fan is located in the shell and is adjacent to the opening, and the fan rotates along with the rotating shaft to generate air flow.

The inner stator assembly is provided with a plurality of heat dissipation channels located on the side wall of the rack, each heat dissipation channel is provided with an air inlet located on the axial end face of the rack and an air outlet located on the annular wall face of the rack, the air inlets are adjacent to the fans, and the air outlets are exposed out of the shell.

The further improvement scheme is as follows: the casing is equipped with annular lateral wall and is located the end wall of annular lateral wall axial one end, annular lateral wall with the end wall encloses to establish form hold the chamber, the opening is located annular lateral wall with at least one of end wall.

The further improvement scheme is as follows: the outer rotor assembly comprises a plurality of magnetic steels attached to the inner wall of the annular side wall, the magnetic steels are uniformly distributed on the inner wall of the annular side wall along the circumferential direction, and the fan is located between the end wall and the magnetic steels.

The further improvement scheme is as follows: the outer rotor component further comprises a magnetic steel frame which is attached to the inner wall of the annular side wall, and the magnetic steel frame is abutted against one axial end of the fan and used for fixing the magnetic steel.

The further improvement scheme is as follows: the structure of magnet steel is tile form or cyclic annular, just magnet steel is made by the neodymium iron boron material.

The further improvement scheme is as follows: the inner stator assembly comprises a winding located on the periphery of the rack, and the winding directly faces the magnetic steel.

The further improvement scheme is as follows: the winding comprises a coil assembly and an annular steel ring which are formed by pressing and winding, and the coil assembly is located between the steel ring and the magnetic steel.

The further improvement scheme is as follows: the coil component comprises a coil and an adhesive integrally formed on the coil, wherein the adhesive comprises epoxy resin, acrylic resin, polyurethane, phenolic resin or a combination thereof.

The further improvement scheme is as follows: the inner stator assembly comprises a bearing positioned between the rotating shaft and the rack, and the rack is axially fixed on the rotating shaft through the bearing.

The further improvement scheme is as follows: the shape of the heat dissipation air duct comprises a circle, an eggplant shape, an ellipse, a triangle, a rectangle, a square or a combination thereof.

Compared with the prior art, the utility model discloses following beneficial effect has: the inner stator assembly is provided with a plurality of heat dissipation channels penetrating through the rack, the heat dissipation channels are provided with air inlets located on the axial end face of the rack and air outlets located on the annular side wall of the rack, the air inlets are adjacent to the fan, and the air outlets are exposed out of the shell. When the pivot drove the fan and rotates, the air current got into external rotor brushless motor from the opening of casing, flowed through heat dissipation channel from the air intake and flowed out external rotor brushless motor from the air outlet after, compared and used water-cooling in the present market, the utility model discloses a heat dissipation channel is safer, reliable. Meanwhile, the outer rotor brushless motor is convenient to operate and maintain, simple and feasible in assembly and suitable for batch production.

[ description of the drawings ]

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings:

fig. 1 is a schematic perspective view of an external rotor brushless motor according to the present invention;

fig. 2 is a partially exploded schematic view of the outer rotor brushless motor shown in fig. 1;

fig. 3 is an exploded schematic view of the outer rotor brushless motor shown in fig. 1;

fig. 4 is a sectional view of the outer rotor brushless motor shown in fig. 1;

fig. 5 is a cross-sectional view of the outer rotor brushless motor shown in fig. 1 at another angle.

The meaning of the reference symbols in the figures:

100. outer rotor brushless motor 10, pivot 20, outer rotor subassembly

21. Housing 211, end wall 212, annular side wall

213. Opening 22, magnet steel 23, magnet steel frame

30. Inner stator assembly 31, frame 311, axial end face

312. Annular wall 32, winding 321, coil assembly

322. Steel ring 33, heat dissipation air duct 331 and air inlet

332. Air outlet 34, bearing 40 and fan

[ detailed description ] embodiments

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention. In the description herein, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Words such as "upper", "lower", "front", "rear", etc., indicating directions or positional relationships described below are based only on directions or positional relationships shown in the drawings, are only for convenience of description of the present invention and to simplify the description, and do not indicate or imply that the devices/elements referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

Referring to fig. 1 to 5, an external rotor brushless motor 100 according to a preferred embodiment of the present invention is generally used for connecting to an electric tool and has the advantages of easy operation and maintenance, simple and feasible assembly, environmental protection, and economy. The outer rotor brushless motor 100 includes a rotating shaft 10 extending along an axial direction, an outer rotor assembly 20 connected to the rotating shaft, an inner stator assembly 30 located between the rotating shaft 10 and the outer rotor assembly 20, and a fan 40 fixed on the rotating shaft, wherein the outer rotor assembly 20 is fixed on the rotating shaft 10, and the rotating shaft 10 rotates with the outer rotor assembly 20 relative to the inner stator assembly 30.

Referring to fig. 2 and 3, the outer rotor assembly 20 includes a housing 21 having one axial end fixed to the rotating shaft 10, the housing 21 is provided with an accommodating cavity and an opening 213 located at one axial end and communicated with the accommodating cavity, the housing 21 is provided with an annular sidewall 212 and an end wall 211 located at one axial end of the annular sidewall 212, the annular sidewall 212 and the end wall 211 are enclosed to form the accommodating cavity, and the opening 213 is located on at least one of the annular sidewall 212 and the end wall 211.

Specifically, the outer rotor assembly 20 includes a plurality of magnetic steels 22 attached to the inner wall of the annular side wall 212, the magnetic steels 22 are uniformly distributed on the inner wall of the annular side wall 212 along the circumferential direction, and the fan 40 is located between the end wall 211 and the magnetic steels 22. The magnetic steel 22 is tile-shaped, and the magnetic steel 22 is made of neodymium iron boron materials. Of course, the magnetic steel 22 can also be annular in structure here.

Referring to fig. 2 to 4, the inner stator assembly 30 includes a frame 31 sleeved outside the rotating shaft 10 and a bearing 34 located between the rotating shaft 10 and the frame 31, the frame 31 is axially fixed on the rotating shaft 10 through the bearing 34, and a portion of the frame 31 is accommodated in the accommodating cavity, the inner stator assembly 30 further includes a winding 32 located on an outer periphery of the frame 31, and the winding 32 is directly disposed toward the magnetic steel 22. The winding 32 comprises a coil assembly 321 and an annular steel ring 322 which are formed by pressing and winding, and the coil assembly 321 is located between the steel ring 322 and the magnetic steel 22.

Specifically, the coil component 321 includes a coil and an adhesive integrally formed on the coil, in this embodiment, the adhesive is an epoxy resin, and the epoxy resin contains a plurality of polar groups and an epoxy group with a large activity, so that the epoxy resin has a strong adhesive force with a material with a high surface activity, and the epoxy resin has a large cohesive strength, so that the adhesive strength is high, and the epoxy resin is substantially free of low-molecular volatile matter during curing, has the advantages of small volume shrinkage, good corrosion resistance and dielectric properties, and is preferably used for integrally forming with the coil. Of course, adhesives such as, but not limited to, acrylics, polyurethanes, phenolics, and the like have similar properties.

Referring to fig. 2, 4 and 5, the inner stator assembly 30 further has a plurality of heat dissipating channels 33 located on the side wall of the rack 31, the heat dissipating channels 33 have an air inlet 331 located on an axial end surface of the rack 31 and an air outlet 332 located on an annular wall surface of the rack 31, the fan 40 is located in the housing 20 and adjacent to the opening 213, the fan 40 rotates along with the rotating shaft 10 to generate an air flow, the air inlet 331 is adjacent to the fan 40, and the air outlet 332 is exposed to the outside of the housing 21. In other words, a plurality of blades of the fan 40 surround the rotating shaft 10, and a plurality of air inlets 331 are formed between adjacent blades so that the airflow generated by the rotation of the blades enters the motor, flows through the heat dissipation channel 33, and then flows out of the air outlet 332. In this embodiment, the heat dissipation air duct 33 is shaped like an eggplant and is uniformly distributed on the rack. In addition, the shape of the heat dissipation air duct 33 may also be circular, eggplant-shaped, oval, triangular, rectangular, square, or a combination thereof.

In the outer rotor brushless motor of the utility model, the coil is three-phase and is wound by a plurality of stranded enameled wires or copper bars to form a cylindrical slotless structure; the shell is made of stainless steel, and has the characteristics of no rust, no magnetic conduction and high strength.

In this embodiment, set up the heat dissipation wind channel in the outer rotor brushless motor and carry out the forced air cooling, compare in using water-cooling on the market at present, safer, operation safety, reliable, operation easy maintenance, the assembly is simple feasible, more environmental protection economy, is fit for batch production.

The present invention is not limited to the above-mentioned embodiments, and those skilled in the art can easily understand that the present invention has many other alternatives without departing from the principle and scope of the present invention, and the protection scope of the present invention is subject to the content of the claims.

Claims

1. An outer rotor brushless motor comprises a rotating shaft extending along the axial direction, an outer rotor assembly connected with the rotating shaft, an inner stator assembly located between the rotating shaft and the outer rotor assembly and a fan fixed on the rotating shaft, wherein the outer rotor assembly comprises a shell of which one axial end is fixed on the rotating shaft, the shell is provided with an accommodating cavity and an opening located at one axial end and communicated with the accommodating cavity, the inner stator assembly comprises a rack sleeved outside the rotating shaft, part of the rack is accommodated in the accommodating cavity, the fan is located in the shell and is adjacent to the opening, and the fan rotates along with the rotating shaft to generate air flow; the method is characterized in that: the inner stator assembly is provided with a plurality of heat dissipation channels positioned on the rack, the heat dissipation channels are provided with air inlets positioned on the axial end face of the rack and air outlets positioned on the annular wall face of the rack, the air inlets are adjacent to the fan, and the air outlets are exposed out of the shell.

2. The external rotor brushless motor of claim 1, wherein: the casing is equipped with annular side wall and is located the end wall of annular side wall axial one end, annular side wall with the end wall encloses to establish and forms hold the chamber, the opening is located annular side wall with at least one of end wall.

3. The external rotor brushless motor of claim 2, wherein: the outer rotor assembly comprises a plurality of magnetic steels attached to the inner wall of the annular side wall, the magnetic steels are uniformly distributed on the inner wall of the annular side wall along the circumferential direction, and the fan is located between the end wall and the magnetic steels.

4. The external rotor brushless motor of claim 3, wherein: the outer rotor component further comprises a magnetic steel frame attached to the inner wall of the annular side wall, and the magnetic steel frame abuts against one axial end of the fan and is used for fixing the magnetic steel.

5. The external rotor brushless motor of claim 3, wherein: the structure of magnet steel is tile shape or cyclic annular, just the magnet steel is made by neodymium iron boron material.

6. The external rotor brushless motor of claim 3, wherein: the inner stator assembly comprises a winding located on the periphery of the rack, and the winding is directly arranged towards the magnetic steel.

7. The external rotor brushless motor of claim 6, wherein: the winding comprises a coil assembly and an annular steel ring which are formed by pressing and winding, and the coil assembly is positioned between the steel ring and the magnetic steel.

8. The external rotor brushless motor of claim 7, wherein: the coil component comprises a coil and an adhesive integrally formed on the coil, wherein the adhesive comprises epoxy resin, acrylic resin, polyurethane, phenolic resin or a combination thereof.

9. The external rotor brushless motor of claim 1, wherein: the inner stator assembly comprises a bearing positioned between the rotating shaft and the rack, and the rack is axially fixed on the rotating shaft through the bearing.

10. The external rotor brushless motor of claim 1, wherein: the shape of the heat dissipation channel comprises a circle, an eggplant shape, an ellipse, a triangle, a rectangle, a square or a combination thereof.