Outer rotor assembly of brushless motor

Abstract

The utility model relates to the technical field of motors, in particular to an outer rotor assembly of a brushless motor. The brushless motor outer rotor assembly comprises a casing, a supporting structure and a plurality of magnetic shoes. The magnetic tile is made of neodymium iron boron; the supporting structure is arranged on the annular inner wall of the machine shell. A plurality of mounting grooves are formed in the supporting structure in the circumferential direction of the machine shell; the number of the mounting grooves is equal to that of the magnetic shoes, and the mounting grooves are matched in a one-to-one correspondence manner, so that the magnetic shoes are clamped in the corresponding mounting grooves. Therefore, the size of the brushless motor can be reduced, the material cost is reduced, and dynamic balance and the rotor air gap size can be controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to an outer rotor assembly of a brushless motor. Background Art

[0002] At present, both fuel vehicles and new energy vehicles are equipped with heat exchange components at the front of the vehicle, including, for example, condensers, radiators, etc., and a cooling fan for driving air circulation is installed behind the radiator. In the prior art, the cooling fan is driven by a brushless motor structure.

[0003] The permanent magnet solutions of brushless motors for automotive cooling fans on the market all use ferrite tiles that are evenly bonded to the inner circle of the rotor housing. Due to the low magnetic properties of ferrite, the volume of ferrite has to be increased to make up for the lack of magnetic properties while meeting the performance of the motor. The corresponding stator core, rotor housing, and copper wire winding will increase their material costs, and the assembly process between the tiles and the housing uses glue dispensing, which is not conducive to controlling dynamic balance and rotor air gap size. Utility Model Content

[0004] The purpose of the utility model includes, for example, providing a brushless motor outer rotor assembly, which can reduce the volume of the brushless motor, reduce material costs, and is conducive to controlling dynamic balance and rotor air gap size.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the utility model provides a brushless motor outer rotor assembly, comprising:

[0007] A housing, a supporting structure and a plurality of magnetic tiles; the material of the magnetic tiles is neodymium iron boron material;

[0008] The support structure is arranged on the annular inner wall of the casing;

[0009] A plurality of mounting grooves are provided on the support structure along the circumferential direction of the housing; the number of the mounting grooves is equal to the number of the magnetic tiles, and they are matched one by one so that the magnetic tiles are snapped into the corresponding mounting grooves.

[0010] In an optional embodiment, along the axial direction of the housing, the support structure includes an outer ring portion, a connecting portion, and an inner ring portion that are connected in sequence;

[0011] The inner ring portion is close to the bottom of the housing, and the outer ring portion is far from the bottom of the housing; and the outer ring portion, the inner ring portion and two adjacent connecting portions together enclose a mounting groove;

[0012] Along the radial direction of the housing, the thickness of the outer ring portion is less than the wall thickness of the magnetic tile, and the thickness of the inner ring portion is equal to the wall thickness of the magnetic tile.

[0013] In an optional embodiment, the support structure further includes an extension portion; the extension portion is disposed on the connecting portion, and the extension portion extends along the axial direction of the housing to a preset position;

[0014] Along the radial direction of the housing, the extension portion has a bottom end close to the connecting portion and a top end away from the connecting portion;

[0015] Along the circumferential direction of the housing, one side of the top extends toward the mounting slot by a preset distance, and the other side of the top extends toward another adjacent mounting slot by a preset distance, so as to hold the top surface of the magnetic tile in the mounting slot in a limited position.

[0016] In an optional embodiment, along the axial direction of the housing, the length of the extending portion is smaller than the length of the connecting portion.

[0017] In an optional embodiment, along the axial direction of the housing, the length of the connecting portion is L1, the length of the extending portion is L2, and the 0.3L1 <L2<0.7L1。

[0018] In an alternative embodiment, L2=0.5L1.

[0019] In an optional embodiment, along the radial direction of the housing, the top surface of the extension portion is flush with the top surface of the inner ring portion.

[0020] In an optional embodiment, the magnetic tile along the circumferential direction of the housing is a skirt side, and the skirt side is provided with a chamfered surface;

[0021] Along the circumferential direction of the housing, the width of the bottom end of the extension portion is the same as the width of the connecting portion, and the extension portion has a matching surface extending from the bottom end to the top end;

[0022] The matching surface is in contact with the chamfered surface.

[0023] In an optional embodiment, the outer ring portion, the connecting portion, the inner ring portion and the extending portion of the support structure are integrally formed.

[0024] In an optional embodiment, the support structure is integrally formed by injection molding.

[0025] In an optional embodiment, the support structure is made of PBT+GF30 material which is integrally molded by injection molding.

[0026] In an optional embodiment, a plurality of small holes are evenly distributed on the outer circumferential surface of the casing along the circumferential direction of the casing; a connecting column is provided on the supporting structure, and the connecting column passes through the small holes to achieve axial and radial positioning of the supporting structure and the casing.

[0027] The beneficial effects of the embodiments of the present utility model include, for example:

[0028] The brushless motor outer rotor assembly of the present solution includes a housing, a support structure and a plurality of magnetic tiles. The plurality of magnetic tiles can be arranged in a one-to-one correspondence in the mounting grooves on the support structure. Because neodymium iron boron magnetic tiles are used, the wall thickness is significantly reduced while the magnetic properties are improved, so that the weight of the permanent magnet can be reduced, which is beneficial to reduce the material cost and facilitate the control of dynamic balance. Furthermore, the magnetic tiles can be firmly fixed on the housing by snapping them into the mounting grooves of the support structure. This connection method improves the problem that the assembly process between the magnetic tiles and the housing in the prior art uses glue dispensing, which affects the dynamic balance and the size of the rotor air gap. In summary, such a brushless motor outer rotor assembly has a simple structure, is easy to process, and is convenient for large-scale assembly line production, and therefore has significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 This is a schematic structural diagram of an outer rotor assembly of a brushless motor according to an embodiment of the utility model;

[0031] Figure 2 It is a partial schematic diagram of the outer rotor assembly of the brushless motor according to an embodiment of the utility model;

[0032] Figure 3 It is a structural schematic diagram of the magnetic shoe of the outer rotor assembly of the brushless motor according to an embodiment of the utility model;

[0033] Figure 4 It is a schematic cross-sectional view of an outer rotor assembly of a brushless motor according to an embodiment of the utility model.

[0034] Icons: 100- housing; 101- small hole; 200- supporting structure; 201- mounting groove; 210- outer ring; 220- connecting part; 230- inner ring; 240- extension part; 241- bottom end; 242- top end; 243- mating surface; 250- connecting column; 300- magnetic tile; 301- head side; 302- tail side; 303- skirt side; 310- chamfered surface. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0038] In the description of the present utility model, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when used. It is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present utility model.

[0039] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0040] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0041] Please refer to Figure 1 The present embodiment provides a brushless motor outer rotor assembly, including a housing 100, a support structure 200 and a plurality of magnetic tiles 300; the material of the magnetic tiles 300 is neodymium iron boron material.

[0042] The support structure 200 is disposed on the annular inner wall of the housing 100;

[0043] Along the circumferential direction of the housing 100 , a plurality of mounting grooves 201 are provided on the support structure 200 ; the number of the mounting grooves 201 is equal to the number of the magnetic tiles 300 , and they are matched one by one so that the magnetic tiles 300 are snapped into the corresponding mounting grooves 201 .

[0044] Multiple magnetic tiles 300 can be arranged in the mounting grooves 201 on the support structure 200 in a one-to-one correspondence. Because neodymium iron boron magnetic tiles 300 are used, the wall thickness is significantly reduced while the magnetic properties are improved, which can reduce the weight of the permanent magnet, help reduce material costs, and facilitate the control of dynamic balance. Furthermore, the magnetic tiles 300 can be firmly fixed on the housing 100 by snapping them into the mounting grooves 201 of the support structure 200. This connection method improves the problem that the assembly process between the magnetic tiles 300 and the housing 100 in the prior art uses glue dispensing, which affects the dynamic balance and the size of the rotor air gap.

[0045] Specifically, the magnetic properties of the common ferrite grade Y38 are: remanence Br ≥ 0.45T, magnetic energy product BHm: 4.6116 ~ 5.1156MGs·Oe.

[0046] The common NdFeB grade N45SH has the following magnetic properties: remanence Br≥1.33T, magnetic energy product BHm≥43MGs·Oe.

[0047] It can be seen from the above parameters that, compared with ferrite, the excellent magnetic properties of NdFeB only require a very thin thickness and volume to meet the motor performance, and the corresponding stator core, rotor housing 100, copper wire winding, etc. can reduce its material cost.

[0048] In addition, due to the excellent magnetic properties of NdFeB, the required materials can be greatly reduced compared to ferrite, resulting in a very thin wall thickness of NdFeB. There is a greater risk of breaking the magnetic tile 300 in the process design. The clamping solution used in this embodiment can greatly reduce the risk of breaking the magnetic tile 300 during assembly.

[0049] Figure 1 It is a schematic diagram of the structure of the outer rotor assembly of the brushless motor. Figure 2 for Figure 1 A partial enlarged view of Figure 2 A magnetic tile 300 is hidden in the figure to illustrate the structure of the mounting groove 201. Figure 3 It is a schematic diagram of the structure of the magnetic tile 300. Figure 4 It is a schematic cross-sectional view along the small hole 101 of the housing 100.

[0050] Please continue reading Figure 1 , Figure 2 , Figure 3 and Figure 4 , to understand more structural details of the outer rotor assembly of the brushless motor. The housing 100 in this embodiment is a hollow ring-shaped barrel structure, the support structure 200 is a circular ring, and the magnetic tile 300 is an arc-shaped plate.

[0051] like Figure 1 , Figure 2 and Figure 3 It can also be seen from the figure that the support structure 200 is annular in shape, and the support structure 200 is pressed against the inner wall of the housing 100. Optionally, in this embodiment, along the radial direction of the housing 100, the bottom of the installation groove 201 is penetrated to form a through channel. That is, the bottom of the installation groove 201 is penetrated, and the groove opening of the installation groove 201 is open. The installation groove 201 and the inner wall of the housing 100 enclose to form a receiving space for accommodating the magnetic tile 300.

[0052] Along the axial direction of the housing 100, the end of the magnetic tile 300 close to the bottom of the housing 100 is the head side 301, and the end of the magnetic tile 300 away from the bottom of the housing 100 is the tail side 302; the circumferential direction of the magnetic tile 300 along the housing 100 is the skirt side 303. The head side 301, the tail side 302 and the skirt side 303 of the magnetic tile 300 are all snap-fitted into the mounting groove 201.

[0053] Further, such as Figure 4 In this embodiment of the utility model, along the circumferential direction of the housing 100, a plurality of small holes 101 are evenly distributed on the outer circumference of the housing 100; a connecting column 250 is provided on the outer circumference of the support structure 200, and the connecting column 250 penetrates the small holes 101 to achieve axial and radial positioning of the support structure 200 and the housing 100. In this way, the support structure 200 is prevented from being separated from the housing 100. Optionally, in this embodiment, four small holes 101 are provided on the housing 100, and the support structure 200 is provided with four connecting columns 250, and the connecting columns 250 are inserted into the small holes 101 one by one.

[0054] It can also be seen from the figure that in this embodiment of the utility model, along the axial direction of the casing 100, the support structure 200 includes an outer ring portion 210, a connecting portion 220 and an inner ring portion 230 connected in sequence; the inner ring portion 230 is close to the bottom of the casing 100, and the outer ring portion 210 is far away from the bottom of the casing 100; and the outer ring portion 210, the inner ring portion 230 and the two adjacent connecting portions 220 together enclose a mounting groove 201; along the radial direction of the casing 100, the thickness of the outer ring portion 210 is less than the wall thickness of the magnetic tile 300, the thickness of the inner ring portion 230 is equal to the wall thickness of the magnetic tile 300, and the thickness of the connecting portion 220 is the same as the thickness of the outer ring.

[0055] That is, the inner diameter of the head side 301 of the magnetic tile 300 is the same as the inner diameter of the inner ring portion 230. The inner diameter of the tail side 302 of the magnetic tile 300 is greater than the inner diameter of the outer ring portion 210.

[0056] In this way, the installation groove 201 forms a good wrapping around the magnetic tile 300, which is conducive to ensuring that the magnetic tile 300 is stably arranged in the installation groove 201. At the same time, because the thickness of the inner ring portion 230 is greater than the thicknesses of the outer ring portion 210 and the connecting portion 220, a stepped shape is formed between the inner ring portion 230 and the connecting portion 220, so that the magnetic tile 300 can be conveniently loaded and unloaded into and from the installation groove 201. It is also conducive to the magnetic tile 300 being positioned by approaching the edge of the outer ring portion 210 through the installation groove 201, facilitating the loading and unloading operations.

[0057] Furthermore, as Figure 1 and Figure 2 , in this embodiment of the present invention, the support structure 200 further includes an extension portion 240; the extension portion 240 is arranged on the connecting portion 220, and the extension portion 240 extends along the axis direction of the casing 100 to a preset position; along the radial direction of the casing 100, the extension portion 240 has a bottom end 241 close to the connecting portion 220 and a top end 242 far from the connecting portion 220; along the circumferential direction of the casing 100, one side of the top end 242 extends a preset distance towards the installation groove 201, and the other side of the top end 242 extends a preset distance towards the adjacent another installation groove 201 to abut and limit the top surface of the magnetic tile 300 in the installation groove 201. The extension portion 240 can ensure the tightness of the fixation of the magnetic tile 300.

[0058] Optionally, in this embodiment of the present invention, along the axis direction of the casing 100, the length of the extension portion 240 is less than the length of the connecting portion 220. That is, in the support structure 200, the radius at the position of the magnetic tile 300 far from the bottom of the casing 100 is less than the inner diameter of the magnetic tile 300, so that a part of the surface of the tail side 302 of the magnetic tile 300 is exposed. This facilitates the loading and unloading of the magnetic tile 300.

[0059] In this embodiment of the present invention, along the axis direction of the casing 100, the length value of the connecting portion 220 is L1, and the length value of the extension portion 240 is L2, 0.3L1 < L2 < 0.7L1. Preferably, in this embodiment, L2 = 0.5L1.

[0060] In this embodiment of the utility model, along the radial direction of the housing 100, the top surface of the extension portion 240 is flush with the top surface of the inner ring portion 230. The skirt side 303 of the magnetic tile 300 along the circumferential direction of the housing 100 is provided with a chamfered surface 310; along the circumferential direction of the housing 100, the width of the bottom end 241 of the extension portion 240 is the same as the width of the connecting portion 220, and the extension portion 240 has a mating surface 243 extending from the bottom end 241 to the top end 242; the mating surface 243 is in contact with the chamfered surface 310. The mating surface 243 and the chamfered surface 310 not only ensure the close contact between the magnetic tile 300 and the support structure 200, but also can limit the top end 242 of the magnetic tile 300.

[0061] Optionally, the chamfered surface 310 is an outer chamfered surface extending along the axis of the housing 100. The mating surface 243 is an inner chamfered surface extending along the axis of the housing 100. The fillet angles of the outer chamfered surface and the inner chamfered surface are the same.

[0062] Furthermore, in this embodiment, the connecting column 250 , the outer ring portion 210 , the connecting portion 220 , the inner ring portion 230 and the extending portion 240 of the supporting structure 200 are integrally formed, which is conducive to ensuring the stability of the supporting structure 200 .

[0063] In this embodiment of the utility model, the support structure 200 is integrally formed by injection molding. This plastic coating solution replaces the conventional dispensing process, so that the dynamic balance of the rotor is significantly improved in consistency, and the air gap size control effect between the magnetic shoe 300 and the stator core is more accurate.

[0064] Optionally, the support structure 200 is made of PBT+GF30 material injection molded in one piece. PBT+GF30 refers to a composite material of polybutylene terephthalate (PBT) and glass fiber filler (GF30), and has the advantages of good high temperature resistance, chemical resistance, dimensional stability, and heat deformation resistance.

[0065] During processing, the structure of the brushless motor outer rotor assembly includes a housing 100, a NdFeB magnetic tile 300, and a support structure 200 formed by injection molding filler.

[0066] Multiple NdFeB magnets 300 of the brushless motor outer rotor assembly are evenly placed in the positioning grooves of the lower mold of the injection mold. The housing 100 is clamped by the upper mold, and after the mold is closed, PBT+GF30 is injected to fill and wrap the four planes of the magnets 300.

[0067] In summary, the embodiment of the utility model provides a brushless motor outer rotor assembly, which has at least the following advantages:

[0068] 1. The permanent magnet of the brushless motor of the automotive cooling fan rotor is made of neodymium iron boron.

[0069] 2. The magnetic tile 300 is assembled using the plastic coating process.

[0070] 3. The head side 301 of the magnetic tile 300 is coplanar with the injection molding filling, while the skirt side 303 is not coplanar with the injection molding filling. The exposed surface of the magnetic tile 300 is used for positioning on the injection mold; small holes 101 are arranged circumferentially on the housing 100 for axial and radial positioning of the magnetic steel.

[0071] The above are only specific implementations of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A brushless motor outer rotor assembly, characterized in that: include: A housing (100), a support structure (200) and a plurality of magnetic tiles (300); the magnetic tiles (300) are made of neodymium iron boron material; The support structure (200) is arranged on the annular inner wall of the housing (100); Along the circumferential direction of the housing (100), the support structure (200) is provided with a plurality of mounting grooves (201); the number of the mounting grooves (201) is equal to the number of the magnetic tiles (300), and they are matched one by one so that the magnetic tiles (300) are snap-fitted into the corresponding mounting grooves (201).

2. The brushless motor outer rotor assembly according to claim 1, characterized in that: Along the axial direction of the housing (100), the support structure (200) comprises an outer ring portion (210), a connecting portion (220), and an inner ring portion (230) which are connected in sequence; The inner ring portion (230) is close to the bottom of the housing (100), and the outer ring portion (210) is far from the bottom of the housing (100); and the outer ring portion (210), the inner ring portion (230) and two adjacent connecting portions (220) together enclose a mounting groove (201); Along the radial direction of the housing (100), the thickness of the outer ring portion (210) is less than the wall thickness of the magnetic tile (300), and the thickness of the inner ring portion (230) is equal to the wall thickness of the magnetic tile (300).

3. The brushless motor outer rotor assembly according to claim 2, characterized in that: The support structure (200) further comprises an extension portion (240); the extension portion (240) is arranged on the connection portion (220), and the extension portion (240) extends to a preset position along the axial direction of the housing (100); Along the radial direction of the housing (100), the extension portion (240) has a bottom end (241) close to the connection portion (220), and a top end (242) away from the connection portion (220); Along the circumferential direction of the housing (100), one side of the top end (242) extends toward the mounting groove (201) by a preset distance, and the other side of the top end (242) extends toward another adjacent mounting groove (201) by a preset distance, so as to hold the top surface of the magnetic tile (300) in the mounting groove (201) in a limited position.

4. The brushless motor outer rotor assembly according to claim 3, characterized in that: Along the axial direction of the housing (100), the length of the extension portion (240) is smaller than the length of the connection portion (220).

5. The brushless motor outer rotor assembly according to claim 3, characterized in that: Along the radial direction of the housing (100), the top surface of the extension portion (240) is flush with the top surface of the inner ring portion (230).

6. The brushless motor outer rotor assembly according to claim 3, characterized in that: The magnetic tile (300) along the circumferential direction of the housing (100) is a skirt side (303), and the skirt side (303) is provided with a chamfered surface (310); Along the circumferential direction of the housing (100), the width of the bottom end (241) of the extension portion (240) is the same as the width of the connecting portion (220), and the extension portion (240) has a mating surface (243) extending from the bottom end (241) to the top end (242); The matching surface (243) is in contact with the chamfered surface (310).

7. The brushless motor outer rotor assembly according to claim 3, characterized in that: The outer ring portion (210), the connecting portion (220), the inner ring portion (230) and the extending portion (240) of the support structure (200) are integrally formed.

8. The brushless motor outer rotor assembly according to claim 7, characterized in that: The support structure (200) is integrally formed by injection molding.

9. The brushless motor outer rotor assembly according to claim 8, characterized in that: The support structure (200) is made of PBT+GF30 material which is integrally molded by injection molding.

10. The brushless motor outer rotor assembly according to claim 1, characterized in that: Along the circumferential direction of the housing (100), a plurality of small holes (101) are evenly distributed on the outer circumferential surface of the housing (100); The support structure (200) is provided with a connecting column (250), and the connecting column (250) passes through the small hole (101) to achieve axial and radial positioning of the support structure (200) and the housing (100).

Images