CN212304964U - Brushless motor with outer rotor - Google Patents

Abstract

The utility model relates to an external rotor brushless motor, which comprises a rotor component and a stator component matched with the rotor component; the rotor component comprises an end cover arranged in a hollow mode, a machine shell which is assembled with the end cover and has a hollow structure with two ends penetrating through, and a rotating shaft with two ends penetrating out of the end cover and the machine shell; the end cover is sleeved on at least part of the shell and forms an integral structure with the shell. The outer rotor brushless motor is sleeved on at least part of the shell through the end cover, and forms an integral structure with the shell, so that the outer rotor brushless motor can be conveniently assembled, the concentricity of the end cover matched with the shell is improved, the noise is reduced, and the production cost of the outer rotor brushless motor is reduced.

Description

Brushless motor with outer rotor

Technical Field

The utility model relates to a motor, more specifically say, relate to an external rotor brushless motor.

Background

At present, most garden tools and electric tools are in a state that a brush motor is changed into a brushless motor, an inner rotor motor is changed into an outer rotor motor, and the market requirement on the price of the outer rotor motor is more and more strict.

An end cover in a rotor assembly of an outer rotor brushless motor in the related art is generally a die-cast aluminum alloy or zinc alloy end cover, the end cover and the shell are generally of a split structure, and the end cover and the shell have the defects of high material cost, high assembly difficulty and poor concentricity and are easy to generate noise.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in that, a modified external rotor brushless motor is provided.

The utility model provides a technical scheme that its technical problem adopted is: constructing an outer rotor brushless motor, which comprises a rotor assembly and a stator assembly matched with the rotor assembly;

the rotor component comprises an end cover arranged in a hollow mode, a machine shell which is assembled with the end cover and has a hollow structure with two ends penetrating through, and a rotating shaft with two ends penetrating out of the end cover and the machine shell; the end cover is sleeved on at least part of the shell and forms an integral structure with the shell.

Preferably, the end cap is a plastic part; the end cover and the shell form an integrated mechanism through injection molding;

the casing is last along circumference interval and evenly distributed supplies the injection molding to glue when moulding plastics and fills in order to prevent a plurality of through-holes that the casing pine takes off.

Preferably, the end cover comprises a hollow cylindrical body and a fan blade arranged at one end of the cylindrical body;

the cylindrical body is sleeved on at least part of the periphery of the shell and forms an integral structure with the shell;

the cylindrical body and the fan blade are integrally formed.

Preferably, the fan blade is provided with a central through hole for the rotating shaft to penetrate through.

Preferably, the rotating shaft and the fan blade form an integral structure.

Preferably, the rotor assembly further comprises a shaft sleeve disposed in the central through hole and engaged with the rotating shaft.

Preferably, the fan blade is a plastic part;

the shaft sleeve comprises a sleeve body and matched bosses which are arranged at two ends of the sleeve body and matched with the fan blade during injection molding of the fan blade;

a step surface matched with the fan blade during the injection molding of the fan blade is arranged at the joint between the matching boss and the sleeve body;

when the fan blade and the shaft sleeve form an integrated structure through injection molding, the wrapping surface of the fan blade is flush with the end part of the step surface far away from one end of the sleeve body.

Preferably, the stator assembly includes a stator core, a coil winding disposed on the stator core, a bracket disposed by inserting the stator core from one end of the stator core, and a circuit board disposed on the bracket;

the shell is sleeved on the periphery of the stator core;

and the two ends of the rotating shaft penetrate out of the stator core.

Preferably, the circuit board is provided with a jack matched with the bracket;

the support is provided with an inserting column which is inserted into the inserting hole and penetrates out of the inserting hole;

one end of the inserting column penetrating out of the inserting hole is matched and fixed with the circuit board through a hot riveting process.

Preferably, the rotor assembly further comprises a plurality of magnetic steels arranged in the casing at intervals;

or the rotor assembly further comprises a magnetic ring which is arranged in the casing and is coaxial with the casing.

Implement the utility model discloses an external rotor brushless motor has following beneficial effect: the outer rotor brushless motor is sleeved on at least part of the shell through the end cover, and forms an integral structure with the shell, so that the outer rotor brushless motor can be conveniently assembled, the concentricity of the end cover matched with the shell is improved, the noise is reduced, and the production cost of the outer rotor brushless motor is reduced.

Drawings

The invention will be further explained with reference to the drawings and examples, wherein:

fig. 1 is a schematic structural diagram of an outer rotor brushless motor according to a first embodiment of the present invention;

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

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

fig. 4 is a partial structural view of a rotor assembly of the outer rotor brushless motor shown in fig. 3;

fig. 5 is an exploded view of a rotor assembly of the outer rotor brushless motor shown in fig. 4;

FIG. 6 is a schematic structural view of a hub of the rotor assembly shown in FIG. 4;

fig. 7 is an exploded view of a stator assembly of the outer rotor brushless motor shown in fig. 3;

FIG. 8 is a structural schematic view of a support of the stator assembly shown in FIG. 7;

FIG. 9 is a schematic structural view of a circuit board of the stator assembly shown in FIG. 7;

fig. 10 is a schematic structural view of an outer rotor brushless motor according to a second embodiment of the present invention;

fig. 11 is an exploded view of the outer rotor brushless motor shown in fig. 10.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 to 3 show a first embodiment of an outer rotor brushless motor according to the present invention. The outer rotor brushless motor can be used as a power output mechanism and can output power to drive external equipment to rotate. The outer rotor brushless motor has the advantages of simple structure, convenience in assembly, low manufacturing cost and low noise.

Further, in the present embodiment, the outer rotor brushless motor may include a rotor assembly 10 and a stator assembly 20 assembled with the rotor assembly 10. The rotor assembly 10 can be matched with the stator assembly 20, and can rotate under the power-on state of the stator assembly 20 to output power. The stator assembly 20 can be energized to rotate the rotor assembly 10.

In this embodiment, the rotor assembly 10 may include an end cap 11, a housing 12, and a shaft 13. The end cap 11 has a hollow structure with an opening at one end. The end cap 11 can be sleeved on at least a part of the casing 12 and can form an integral structure with the casing 12, thereby facilitating the assembly of the outer rotor brushless motor, improving the concentricity of the end cap 11 and the casing 12, reducing the noise generation and reducing the production cost of the outer rotor brushless motor. The rotation shaft 13 may be extended from both ends of the end cover 11 and the housing 12, and may be extended from the stator assembly 20, may form an integrated structure with the end cover 11, and may be used to output power by rotation.

As shown in fig. 2 to 5, further, in the present embodiment, the end cover 11 may be a plastic part as a whole, and the material cost of the motor rotor assembly 10 may be reduced by forming the end cover 11 by using the plastic part. The end cap 11 may include a cylindrical body 111 and a fan blade 112, and the cylindrical body 111 may be a hollow structure with two ends penetrating through. Specifically, in some embodiments, the cylindrical body 111 may be cylindrical. It is understood that in other embodiments, the cylindrical body 111 may not be limited to being cylindrical. The fan blade 112 can be disposed at one end of the cylindrical body 111, and can be integrally formed with the cylindrical body 111. Specifically, in some embodiments, the fan blade 112 and the cylindrical body 111 may be integrally formed by injection molding. In some embodiments, the cylindrical body 111 may be sleeved on at least a portion of the outer periphery of the casing 12, and specifically, the cylindrical body 111 may be sleeved from one end of the casing 12 and may have a height smaller than that of the casing 12. The cylindrical body 111 may be formed as an integral structure with the housing 12. Specifically, the cylindrical body 111 and the casing 12 may be formed as an integral structure by injection molding. During preparation, the housing 12 may be placed in a mold for forming the end cap 11, and then injection molding glue is injected into the mold to form the end cap 11 integrated with the housing 12. In some embodiments, the inner side of the end cap 11 may form an annular cavity 113 that mates with the housing 12. In this embodiment, the rotating shaft 13 and the fan blade 112 may also form a separate structure. The fan blade 112 may be provided with a central through hole 1121, and the central through hole 1121 may be located at a central axis of the fan blade 12 and may penetrate through the fan blade 112 along a thickness direction of the fan blade 112. The inner diameter of the central through hole 1121 may be slightly larger than the inner diameter of the rotating shaft 13, so as to facilitate the rotating shaft 13 to pass through.

Further, in some other embodiments, the rotating shaft 13 may form an integral structure with the fan blade 112. Specifically, the rotating shaft 13 and the fan blades 112 may be formed into an integral structure through injection molding. In this embodiment, during the manufacturing process, the housing 12 may be placed in a mold for forming the end cap 11, the rotating shaft 13 is inserted into the housing 12, and both ends of the rotating shaft penetrate out of the housing 12, one end of the rotating shaft is positioned in the mold, and the other end of the rotating shaft forms a free end, and the end cap 11 integrated with the housing 12 and the rotating shaft 13 is formed by injecting injection molding glue into the mold.

Further, in this embodiment, the casing 12 may be a hollow structure with two ends penetrating, and may be cylindrical, and the radial dimension of the casing may be adapted to the radial dimension of the inside of the end cover 11. It will be appreciated that in other embodiments, the housing 12 may not be limited to being cylindrical. In some embodiments, the housing 12 may be made of metal. Of course, it is understood that in other embodiments, the material of the housing 12 may not be limited to metal. The housing 12 may be made of plastic. In some embodiments, a plurality of through holes 121 may be formed in the casing 12, and the through holes 121 may be disposed near one end of the casing 12 and may be spaced and uniformly distributed along the circumference of the casing 12, so as to be filled with injection molding glue during injection molding, thereby preventing the casing 12 from loosening, and improving the axial force and the radial force of the rotor assembly 10, and improving the dynamic balance of the entire rotor assembly 10.

Further, in this embodiment, the rotating shaft 13 may have a cylindrical shape, and the length thereof may be greater than the sum of the heights of the casing 12 and the end cover 11. The shaft 13 and the end cap 11 may be separate structures, but it is understood that in other embodiments, the shaft and the end cap 11 may be formed as a single structure by injection molding.

As shown in fig. 5 and 6, further, in the present embodiment, the rotor assembly 10 may further include a shaft sleeve 14. The shaft sleeve 14 can be installed in the central through hole 1121, and can be sleeved on the periphery of the rotating shaft 13, and can be matched with the rotating shaft 13. In some embodiments, the shaft sleeve 14 may be formed as an integral structure with the fan blade 112. In some embodiments, the sleeve 14 may include a sleeve body 141, a fitting boss 142, and a positioning boss 143. The sleeve 141 may be cylindrical, and a plurality of ribs may be disposed on the outer circumference of the sleeve side by side, so as to improve the stability of the engagement with the fan blade 112. The matching bosses 142 may be disposed at two ends of the sheath 141, and the matching bosses 142 may be circular. The radial dimension of the fitting boss 142 may be smaller than the radial dimension of the sleeve 141. The fitting boss 142 can be integrally formed with the sheath 141. The sleeve 14 may be a plastic component, and the sleeve 141 and the matching boss 142 may be formed integrally by injection molding. Of course, it is understood that in other embodiments, the sleeve 14 may be a metal piece, and the sleeve body 141 and the matching boss 142 may be integrally formed by casting. In this embodiment, a step surface 143 may be disposed at a connection position between the engaging protrusion 142 and the sheath 141. In some embodiments, the shaft sleeve 14 and the fan blade 112 may be formed into an integral structure by injection molding. When the shaft sleeve 14 and the fan blade 112 are injection molded, the injection molding glue can be filled on the step surface 143 of the shaft sleeve 14, so that the shaft sleeve 14 and the fan blade 112 can be conveniently matched and fixed. When the fan blade 112 and the shaft sleeve 14 are formed into an integral structure through injection molding, the wrapping surface of the fan blade 112 can be flush with the end of the step surface 143 away from one end of the sleeve body 141. Of course, it is understood that in other embodiments, the sleeve 14 may be a separate structure from the end cap 11, and the mating boss 142 may be omitted. In this embodiment, two positioning bosses 143 may be disposed corresponding to the matching bosses 142, respectively, and the positioning bosses 143 may be disposed on a side of the matching bosses 142 opposite to the sheath 141. The locating boss 143 may be annular in shape and may be sized smaller than the radial dimension of the mating boss 142 for locating with a bearing. The positioning boss 143 may be integrally formed with the mating boss 142.

As further shown in fig. 2 and 3, the rotor assembly 10 may further include a magnetic ring 15. The magnetic ring 15 may be a hollow cylindrical structure with two ends penetrating. The outer diameter of the magnetic ring 15 may be slightly smaller than the inner diameter of the housing 12. The casing 12 can be sleeved on the periphery of the magnetic ring 15, and the magnetic ring 15 can be sleeved on the periphery of the rotating shaft 13.

Further, in the present embodiment, the rotor assembly 10 may further include a first bearing 16, and the first bearing 16 may be sleeved on a section of the rotating shaft 13 that penetrates through the end cover 11, so as to facilitate the rotation of the rotating shaft 13.

Further, as shown in fig. 2, 7-9, in some embodiments, the stator assembly 20 may include a stator core 21, a coil winding 22, a bracket 23, a circuit board 24, and a stator seat 25. The housing 12 may be disposed around the stator core 21. Specifically, in some embodiments, the stator core 21 may be disposed in the magnetic ring 15, and the rotating shaft 13 may be disposed on the stator core 21, and two ends of the rotating shaft may respectively protrude from two ends of the stator core 21. The coil winding 22 can be wound on the stator core 21, specifically, the coil winding 22 can be a plurality of groups, and the plurality of groups of coil windings 22 can be disposed corresponding to the external teeth of the stator core 21 and can be wound on the external teeth of the stator core 21. The bracket 23 may be inserted into the stator core 21 from one end of the stator core 21, and may be used for mounting the circuit board 24. In some embodiments, the wiring board 14 may be a Hall board. The stator holder 25 may be disposed through the stator core 21 from one end of the stator core 21, and may be used to mount and position the stator core 21.

Further, in the present embodiment, the bracket 23 may include an annular body 231 and an insertion convex portion 232. The annular body 231 may be annular and may be used to support the circuit board 24. The inserting convex portion 232 can be disposed on one side of the annular body 231, can protrude from the annular body 231, and can be integrally formed with the annular body 231, and the inserting convex portion 232 can be inserted into the stator core 21 and is connected and fixed with the stator core 21 by setting glue. Specifically, in some embodiments, the plug-in protrusion 232 may be integrally formed with the annular body 231 by injection molding. The support 23 is provided with a plug column 233, the plug column 233 can be disposed on a side of the annular body 231 opposite to the plug convex portion 232, and the annular body 231 can be integrally formed to be used for mounting and positioning the circuit board 24.

In this embodiment, the circuit board 24 may include a PCB substrate 241 and a hall sensor 242 disposed on the PCB substrate 241. The PCB substrate 241 may have a ring shape, which may be mounted on the bracket 23. The plurality of hall sensors 242 may be provided, and the plurality of hall sensors 242 may be disposed on the PCB substrate 241 at intervals. In some embodiments, the circuit board 24 may be provided with a plurality of insertion holes 2411, and the plurality of insertion holes 2411 may be arranged on the PCB substrate 241 at intervals along the circumferential direction of the PCB substrate 241. The insertion hole 2411 may be used to cooperate with the bracket 23. Specifically, in some embodiments, the plug column 233 can be disposed to be inserted into the receptacle 2411 and can be disposed to be extended out of the receptacle 2411. One end of the plug column 233 penetrating through the insertion hole 2411 can be fixed to the circuit board 24 by hot riveting, so as to improve the stability of the circuit board 24 in cooperation with the bracket 23.

In this embodiment, the stator base 25 may include a base 251 and a positioning column 252 already disposed on the base 251 and protruding from the base 251. The base 251 can be located at one end of the positioning post 252, and the cross-sectional dimension can be larger than the cross-sectional dimension of the positioning post 252. The positioning post 252 can be inserted into the stator core 21 and can be used for installing and positioning the stator core 21.

In this embodiment, the stator assembly 20 further includes a second bearing 26 and a third bearing 27, and the second bearing 26 can be installed at an end of the positioning pillar 252 away from the seat 251. The third bearing 27 can be installed in the housing 251. The second bearing 26 and the third bearing 27 can be sleeved on the rotating shaft 13, so as to facilitate the rotation of the rotating shaft 13.

Fig. 10 and 11 show a second embodiment of the external rotor brushless motor of the present invention, which is different from the first embodiment in that the rotor assembly 10 can replace the magnetic ring 15 with a plurality of magnetic steels 17. In this embodiment, the plurality of magnetic steels 17 may be disposed at intervals along the circumferential direction of the casing 12. The end cover 11 may have a plurality of limiting protrusions 114 therein, and the limiting protrusions 114 may be disposed on the inner sidewall of the end cover 11 at intervals along the circumferential direction of the end cover 11 and may protrude from one end of the end cover 11. A slot 115 can be formed between the two adjacent limiting convex parts 114, and the slot 115 can be arranged in one-to-one correspondence with the magnetic steel 17 and can be used for inserting the magnetic steel 17 and limiting the magnetic steel 17.

It is to be understood that the foregoing examples merely represent preferred embodiments of the present invention, and that the description thereof is more specific and detailed, but not intended to limit the scope of the invention; it should be noted that, for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention; therefore, all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims (10)

1. An outer rotor brushless motor is characterized by comprising a rotor assembly (10) and a stator assembly (20) matched with the rotor assembly (10);

the rotor assembly (10) comprises an end cover (11) arranged in a hollow mode, a machine shell (12) which is assembled with the end cover (11) and is of a hollow structure, and a rotating shaft (13) with two ends penetrating through the end cover (11) and the machine shell (12); the end cover (11) is sleeved on at least part of the shell (12) and forms an integral structure with the shell (12).

2. The external rotor brushless motor of claim 1, wherein the end cap (11) is a plastic part; the end cover (11) and the shell (12) are formed into an integrated mechanism through injection molding;

the shell (12) is circumferentially spaced and uniformly distributed, and a plurality of through holes (121) are filled with injection molding glue during injection molding to prevent the shell (12) from loosening.

3. The external rotor brushless motor according to claim 1, wherein the end cap (11) comprises a hollow cylindrical body (111), and fan blades (112) disposed at one end of the cylindrical body (111);

the cylindrical body (111) is sleeved on the periphery of at least part of the shell (12) and forms an integral structure with the shell (12);

the cylindrical body (111) and the fan blade (112) are integrally formed.

4. The external rotor brushless motor of claim 3, wherein the fan blades (112) are provided with central through holes (1121) for the rotation shaft (13) to penetrate through.

5. The external rotor brushless motor of claim 4, wherein the rotating shaft (13) and the fan blades (112) form an integral structure.

6. The external rotor brushless motor according to claim 4, wherein the rotor assembly (10) further comprises a bushing (14) disposed in the central through hole (1121) and engaged with the rotating shaft (13).

7. The external rotor brushless electric machine of claim 6, wherein the fan blades (112) are plastic parts;

the shaft sleeve (14) comprises a sleeve body (141) and matching bosses (142) which are arranged at two ends of the sleeve body (141) and are matched with the fan blade (112) when the fan blade (112) is subjected to injection molding;

a step surface (143) which is matched with the fan blade (112) when the fan blade (112) is subjected to injection molding is arranged at the joint between the matching boss (142) and the sleeve body (141);

when the fan blade (112) and the shaft sleeve (14) form an integral structure through injection molding, the wrapping surface of the fan blade (112) is flush with the end part of the step surface (143) far away from one end of the sleeve body (141).

8. The external rotor brushless motor of claim 1, wherein the stator assembly (20) comprises a stator core (21), a coil winding (22) disposed on the stator core (21), a bracket (23) disposed by inserting the stator core (21) from one end of the stator core (21), and a circuit board (24) disposed on the bracket (23);

the shell (12) is sleeved on the periphery of the stator core (21);

and two ends of the rotating shaft (13) penetrate out of the stator iron core (21).

9. The external rotor brushless motor according to claim 8, wherein the circuit board (24) is provided with a jack (2411) engaged with the bracket (23);

the support (23) is provided with an insertion column (233) which is inserted into the insertion hole (2411) and penetrates out of the insertion hole (2411);

one end of the inserting column (233) penetrating out of the inserting hole (2411) is matched and fixed with the circuit board (24) through a hot riveting process.

10. The external rotor brushless motor of claim 1, wherein the rotor assembly (10) further comprises a plurality of magnetic steels (17) disposed in the casing (12) and spaced apart;

or the rotor assembly (10) further comprises a magnetic ring (15) which is arranged in the casing (12) and is coaxial with the casing (12).

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