Inner rotor brushless motor convenient for heat dissipation

Abstract

The utility model discloses an inner rotor brushless motor convenient for heat dissipation, which comprises a shell assembly, a stator assembly, a rotor assembly and a fan, and is characterized in that the stator assembly is mounted in the shell assembly; the rotor assembly is located in the stator assembly, and the two ends penetrate through the shell assembly and are rotationally connected with the shell assembly. The fan is located outside the shell assembly and installed at the output end of the rotor assembly, the fan comprises a base plate and a plurality of fan blades installed at one end of the base plate, a wind gathering inclined face is arranged on the side, facing the shell assembly, of the base plate, and the distance between the wind gathering inclined face and the shell assembly is decreased along with increasing of the radial size. According to the utility model, the chassis of the fan is designed at a certain angle to form a wind-gathering inclined plane, so that a certain wind-gathering effect is increased, and the heat dissipation of the motor can be better.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to an inner rotor brushless motor which is convenient for heat dissipation. Background Art

[0002] The inner rotor brushless motor is a DC motor with a simple structure that requires a driver. Compared with traditional brushed motors, this motor has the advantages of high efficiency, low noise, long life and more precise control. It is usually used in aerospace, robotics, automobiles, medical equipment and other fields. In the future, as brushless motors continue to improve and perfect, they will be used in more fields.

[0003] The current inner rotor motor still has the following problems:

[0004] First, the existing inner rotor motor with high speed, excessive current and high coil heat generation is cooled by setting a fan. However, in a relatively closed environment, when the fan airflow is directed in a single direction for directional heat dissipation, the heat dissipation effect is poor.

[0005] Second, the current assembly process of the stator and the housing in the inner rotor motor is complicated and the production cost is high. For example, the existing regular circuit board 4 and the stator assembly 2 are fixed with the first screw 16 (see below). Figure 8 ), it is too cumbersome to fix, and the circuit board needs to be adjusted to a specific position. Because a regular circuit board has a centrally symmetrical and / or axially symmetrical ring-like structure, it can still be installed after rotating a certain angle, but the different installation positions are not only inconvenient for welding the connecting wires, but also affect the installation of the end cover. At the same time, the position of the stator installed in the casing also needs to be positioned. It is easy to make mistakes during manual assembly, resulting in rework, and the assembly efficiency of the whole machine is low. Utility Model Content

[0006] In order to solve the technical problems of the inner rotor motor in the prior art that the fan airflow has a single direction and the heat dissipation effect is poor, the utility model provides an inner rotor brushless motor that is easy to dissipate heat to solve the above problems.

[0007] The utility model adopts the following technical solution to solve the technical problem: an inner rotor brushless motor which is convenient for heat dissipation, comprising a shell assembly, a stator assembly, a rotor assembly and a fan, wherein the stator assembly is installed in the shell assembly; the rotor assembly is located in the stator assembly, and both ends of the rotor assembly pass through the shell assembly and are rotatably connected to the shell assembly; the fan is located outside the shell assembly and is installed at the output end of the rotor assembly, the fan comprises a chassis and a plurality of fan blades installed at one end of the chassis, a wind-gathering inclined surface is provided on a side of the chassis facing the shell assembly, and a distance between the wind-gathering inclined surface and the shell assembly decreases with an increase in a radial dimension.

[0008] Furthermore, the wind-gathering inclined surface is a plane, and the included angle a between the wind-gathering inclined surface and the end surface of the fan is 20° to 40°.

[0009] Furthermore, the chassis also has an upper plane and a lower plane that are not in the same plane, the wind-gathering slope is connected by the upper plane and the lower plane, the upper plane and the lower plane are parallel to the end face of the fan and the distance between the upper plane and the shell assembly is relatively close.

[0010] Furthermore, an annular cylinder is provided at the center of the chassis, the annular cylinder is connected to the lower plane, a metal sleeve is installed in the annular cylinder, and the metal sleeve is connected to the output shaft of the rotor assembly.

[0011] Furthermore, the chassis and the fan blades are both made of plastic, and the metal sleeve is made of aluminum or copper.

[0012] Furthermore, the height difference between the upper plane and the lower plane is 2 mm to 2.5 mm.

[0013] Furthermore, the outer peripheral surface of the metal sleeve has grid knurling, and the metal sleeve and the fan are injection molded as one body.

[0014] Furthermore, a plurality of heat dissipation ribs are provided on the outer peripheral surface of the shell assembly.

[0015] Furthermore, the stator assembly and the housing assembly are clearance-matched, and the motor also includes a circuit board and a positioning assembly, the circuit board is installed at one end of the stator assembly and is sleeved on the outside of the rotor assembly, and the positioning assembly includes a first asymmetric positioning mechanism arranged between the stator assembly and the housing assembly and a second asymmetric positioning mechanism arranged between the stator assembly and the circuit board, so that the circuit board, the stator assembly and the housing assembly form a unique connection relationship.

[0016] Furthermore, the first asymmetric positioning mechanism includes:

[0017] Two or more positioning ribs are fixed on the inner wall of the shell component and are arranged in a non-centrally symmetrical and non-circular array with respect to the shell component; positioning grooves are opened on the outer wall of the stator component and correspond to the positioning ribs.

[0018] The second asymmetric positioning mechanism comprises:

[0019] Two or more rivet posts are fixed at one end of the stator assembly and are arranged in a non-centrally symmetrical and non-circular array with respect to the stator assembly; riveting holes are opened on the circuit board and are correspondingly matched with the rivet posts.

[0020] Furthermore, the shell assembly includes a rear end cover, a casing and a front end cover, the rear end cover and the front end cover are fixed by screws, and the positioning ribs extend axially to both ends of the casing, and both ends of the positioning ribs are chamfered.

[0021] Furthermore, the inner wall of the casing has a first guide groove corresponding to the screws one by one, and a convex column is formed on the corresponding outer wall of the first guide groove. The outer wall of the stator assembly has a second guide groove opposite to the first guide groove, and the first guide groove and the second guide groove form a slot hole for the screw to pass through.

[0022] Furthermore, the rivet holes and the rivet studs are connected by hot riveting.

[0023] Furthermore, the casing is formed by extrusion of aluminum profiles.

[0024] The beneficial effects of the utility model are:

[0025] (1) The utility model designs the chassis of the fan at a certain angle to form a wind-gathering slope, thereby increasing the wind-gathering effect to a certain extent and enabling the motor to dissipate heat better.

[0026] (2) The metal sleeve assembled in the middle of the fan of the utility model is made of aluminum or copper material, and the outer circle of the metal sleeve adopts a mesh knurling structure, which can effectively avoid the fan falling off caused by the softening of the fan material when the motor is running at high power and high temperature.

[0027] (3) The casing of the utility model is made of a material with high thermal conductivity, and heat dissipation ribs are arranged on the outside, which is beneficial to the heat dissipation of the motor.

[0028] (4) The utility model uses the first asymmetric positioning mechanism and the second asymmetric positioning mechanism to form a unique connection relationship between the circuit board, the stator assembly and the housing assembly, so as to prevent errors during assembly, achieve precise installation, and improve assembly efficiency. At the same time, the housing assembly and the stator assembly are clearance-matched, and the first positioning mechanism is used to ensure that the two are firmly connected. Compared with the shrink-fit connection, the production cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0030] Figure 1 It is an exploded view of the inner rotor brushless motor for easy heat dissipation described in the utility model;

[0031] Figure 2 It is a three-dimensional diagram of the inner rotor brushless motor for easy heat dissipation described in the utility model;

[0032] Figure 3 It is a schematic diagram of the connection between the fan and the metal sleeve in the utility model;

[0033] Figure 4 It is an axial cross-sectional view of the utility model (the direction indicated by the arrow is the direction of wind flow);

[0034] Figure 5yes Figure 4 The enlarged image at a in the middle;

[0035] Figure 6 It is an axial cross-sectional view of a brushless motor with a fan in the prior art (the direction indicated by the arrow is the direction of wind flow);

[0036] Figure 7 It is a three-dimensional diagram of the casing of the utility model;

[0037] Figure 8 It is an exploded diagram of the assembly structure of the circuit board and the stator assembly in the prior art;

[0038] Fig. 9 It is a top view of the casing of the utility model;

[0039] Fig.10 It is an axial cross-sectional view of the casing of the utility model;

[0040] Fig.11 It is a top view of the stator assembly in the utility model;

[0041] Fig.12 It is a schematic diagram of the assembly of the stator assembly and the housing in the utility model;

[0042] Fig.13 It is a top view of the circuit board in the utility model;

[0043] Fig.14 This is a schematic diagram of the riveting structure of the circuit board and the stator assembly in the utility model;

[0044] Fig.15 It is a schematic diagram of a specific implementation of the rivet stud in the utility model;

[0045] Fig.16 It is a structural schematic diagram of the rotor assembly in the utility model;

[0046] Fig.17 It is a front view of a surface mounted rotor assembly in the prior art.

[0047] In the figure, 1, shell assembly, 101, rear end cover, 102, casing, 103, front end cover, 2, stator assembly, 3, rotor assembly, 301, rotor core, 302, magnetic tile, 4, circuit board, 5, fan, 501, chassis, 5011, wind gathering slope, 5012, upper plane, 5013, lower plane, 5014, annular cylinder, 502, fan blade, 6, metal sleeve, 7, positioning rib, 701, chamfer, 8, positioning groove, 9, rivet column, 901, riveting part, 902, limiting part, 903, limiting surface, 904, buckle, 10, riveting hole, 11, first screw, 12, first guide groove, 13, boss, 14, second guide groove, 15, mounting groove, 16, screw, 17, heat dissipation rib. DETAILED DESCRIPTION

[0048] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0049] Embodiment 1

[0050] like Figure 1-Figure 3 As shown, an inner rotor brushless motor that is easy to dissipate heat includes a shell assembly 1, a stator assembly 2, a rotor assembly 3 and a fan 5, wherein the stator assembly 2 is installed in the shell assembly 1; the rotor assembly 3 is located in the stator assembly 2, and both ends of the rotor assembly 3 pass through the shell assembly 1 and are rotatably connected to the shell assembly 1; the fan 5 is located outside the shell assembly 1 and is installed at the output end of the rotor assembly 3. After the motor is started, the rotor assembly 3 drives the fan 5 to rotate, which can dissipate heat and cool the motor. The fan 5 includes a chassis 501 and a plurality of fan blades 502 installed at one end of the chassis 501, and the fan blades 502 are located between the shell assembly 1 and the chassis 501. The chassis 501 acts as a wind shield, so that the wind flows to one side of the shell assembly 1. A wind gathering slope 5011 is provided on the side of the chassis 501 facing the shell assembly 1, and the distance between the wind gathering slope 5011 and the shell assembly 1 decreases with the increase of the radial dimension, that is, the wind gathering slope 5011 is in a shape that is wrapped toward the center.

[0051] By comparison Figure 4 and existing Figure 6 The difference in the structure of the chassis 501 of the fan 5 is Figure 6 The chassis 501 of the fan 5 shown is a flat angle, so the wind direction is mostly radial wind. In a closed environment, the wind direction is too scattered and the amount of air that can be circulated is small. Figure 4 and Figure 5The chassis 501 of the middle fan 5 has an inclined surface, so that the blown wind has a large turn, which will sharply increase the amount of air that can circulate in a closed environment and enhance the wind gathering effect, thereby greatly enhancing the heat dissipation effect of the motor and allowing the motor to maintain good working performance for a longer time.

[0052] The wind gathering slope 5011 can be a curved surface or a flat surface or a stepped surface. The wind gathering slope 5011 in this embodiment is a flat surface. The inclination angle of the wind gathering slope 5011 (that is, the angle a between the wind gathering slope 5011 and the end surface of the fan 5 at one axial end) needs to be reasonably set. If the inclination angle a is too small, the wind gathering effect will be small, and if it is too large, it will be blocked too much by the motor body. Therefore, as a preferred embodiment, the angle a between the wind gathering slope 5011 and the end surface of the fan 5 is 20°~40° (such as Figure 5 as shown).

[0053] The shape of chassis 501:

[0054] like Figure 5 As shown, the chassis 501 also has an upper plane 5012 and a lower plane 5013 that are not in the same plane, and the wind-gathering inclined plane 5011 is connected by the upper plane 5012 and the lower plane 5013. The upper plane 5012 and the lower plane 5013 are parallel to the end surface of the fan 5, and the distance between the upper plane 5012 and the housing assembly 1 is relatively close, that is, the upper plane 5012 is located radially outside the wind-gathering inclined plane 5011, and the lower plane 5013 is located radially inside the wind-gathering inclined plane 5011. The fan blades 502 are radially attached to the lower plane 5013, the wind-gathering inclined plane 5011, and the upper plane 5012. The side of the chassis 501 facing away from the wind-gathering inclined plane 5011 is also correspondingly set to an inclined plane parallel to it, so that the thickness of the chassis 501 is consistent.

[0055] The chassis 501 and the fan blades 502 are usually made of plastic material, which can reduce the weight of the motor.

[0056] Installation of chassis 501 and motor output shaft:

[0057] An annular cylinder 5014 is provided at the center of the chassis 501, and the annular cylinder 5014 is connected to the lower plane 5013. A metal sleeve 6 is installed in the annular cylinder 5014, and the metal sleeve 6 is connected to the output shaft of the rotor assembly 3. The metal sleeve 6, as the name implies, is a sleeve structure made of metal material. After the metal sleeve 6 is manufactured, it is injection molded as a whole with the fan 5, and the inner hole of the metal sleeve 6 is installed with an interference fit with the output shaft of the rotor assembly 3. The outer peripheral surface of the metal sleeve 6 has a grid knurling, which can enhance the fixing effect of the metal sleeve 6 and the fan 5. At the same time, the metal sleeve 6 is preferably made of aluminum or copper material, which can effectively avoid the fan 5 falling off due to the softening of the fan 5 material when the motor is running at high power and high temperature.

[0058] The height difference between the upper plane 5012 and the lower plane 5013 is preferably 2 mm to 2.5 mm. The two planes are connected together by wind gathering and tilting, presenting a step-like shape. The blades 502 of the fan 5 are evenly distributed on the chassis 501. Figure 3 As shown; the whole is then pressed onto the shorter rotor shaft of the whole machine (the rear end of the whole machine, interference fit), and the end face of the annular cylinder 5014 of the fan 5 is flush with the end face of the output shaft of the rotor assembly 3.

[0059] The shell assembly 1 generally includes a rear end cover 101, a housing 102 and a front end cover 103. The rear end cover 101 and the front end cover 103 are fixed by screws 16. Both the front end cover 103 and the rear end cover 101 are provided with mounting holes for connecting the screws 16. The housing 102 is clamped between the front end cover 103 and the rear end cover 101.

[0060] The housing 102 is preferably formed by extrusion of aluminum profiles with high thermal conductivity. Compared with the traditional housing 102 made of iron materials, it has good heat dissipation, light weight and does not require surface anti-rust treatment. Figure 7 As shown, we can add a suitable number of long heat dissipation ribs 17 on the outer wall of the housing 102, the thickness of each heat dissipation rib 17 is about 2 mm, the interval between adjacent heat dissipation ribs 17 is about 3 mm, and the length is equal to the height of the outer wall of the housing 102. The advantages are: the contact area between the housing 102 and the external environment is increased, the heat dissipation performance of the motor is further enhanced, and the motor can maintain a good performance state for a long time.

[0061] Rotor assembly 3:

[0062] The rotor assembly 3 generally includes a rotor core 301 and magnetic tiles 302 . In this embodiment, the rotor core 301 is provided with a plurality of axially penetrating mounting grooves 15 . The plurality of mounting grooves 15 are evenly distributed along the circumferential direction, and the magnetic tiles 302 are mounted in the mounting grooves 15 .

[0063] like Fig.16 As shown, four mounting slots 15 penetrating the rotor core 301 are evenly distributed around the inside of the rotor core 301 , and the magnetic tiles 302 are divided into N poles and S poles, which are symmetrically distributed in pairs.

[0064] Conventional surface mounted rotor assembly 3, such as Fig.17 As shown, four evenly distributed notches are processed on the outer surface of the rotor core 301 , and the N poles and S poles of the magnetic tiles 302 are symmetrically distributed on the outer surface of the rotor core 301 .

[0065] In an inner rotor motor, when the motor speed is high, a large centrifugal force will be generated, which makes it easy for the magnetic tiles 302 of the surface-mounted rotor structure to fall off, causing damage to the motor. Therefore, we adopt an embedded rotor structure. When the centrifugal force is very large, the magnetic tiles 302 can be firmly embedded in the rotor core 301, thereby avoiding the occurrence of the magnetic tiles 302 falling off and ensuring the structural stability of the rotor assembly 3.

[0066] The inner rotor brushless motor of this embodiment can be applied to the field of servo motor drive and control integrated system.

[0067] Embodiment 2

[0068] On the basis of the first embodiment, the present embodiment improves the assembly structure of the motor, specifically: the stator assembly 2 is clearance-matched with the housing assembly 1, the motor further comprises a circuit board 4 and a positioning assembly, the circuit board 4 is mounted at one end of the stator assembly 2 and sleeved on the outside of the rotor assembly 3, the positioning assembly comprises a first asymmetric positioning mechanism arranged between the stator assembly 2 and the housing assembly 1 and a second asymmetric positioning mechanism arranged between the stator assembly 2 and the circuit board 4, so that the circuit board 4, the stator assembly 2 and the housing assembly 1 form a unique connection relationship.

[0069] The utility model can uniquely determine the assembly relationship of the circuit board 4, the stator assembly 2 and the housing assembly 1 through two asymmetric positioning mechanisms, and will not cause wrong assembly, thereby avoiding rework. The assembly of the stator assembly 2 and the housing assembly 1 is improved from the traditional shrink fit interference fit to a clearance fit, and no special shrink fit equipment is required. At the same time, the first asymmetric positioning mechanism is used to compensate for the matching strength of the two, so the installation difficulty and production cost are reduced, and the assembly efficiency of the whole machine is greatly improved.

[0070] The first asymmetric positioning mechanism comprises:

[0071] like Figure 9-12 As shown, two or more positioning ribs 7 are fixed to the inner wall of the shell assembly 1, and the positioning ribs 7 are arranged in a non-centrally symmetrical and non-circular array with respect to the shell assembly 1; the positioning grooves 8 are opened on the outer wall of the stator assembly 2 and correspond to the positioning ribs 7.

[0072] The number of positioning ribs 7 can be an odd number or an even number. When the number of positioning ribs 7 is an odd number, each positioning rib 7 is arranged in a non-circular array with respect to the housing assembly 1. At this time, the positional relationship between the housing assembly 1 and the stator assembly 2 can be uniquely determined. The number of positioning ribs 7 is three or more, which makes the connection between the housing assembly 1 and the stator assembly 2 more firmly under the premise of convenient installation. When the number of positioning ribs 7 is an even number, each positioning rib 7 is arranged in a non-center-symmetrical arrangement with respect to the housing assembly 1. The non-center-symmetrical arrangement includes both a non-circular array and a non-axisymmetric arrangement. At this time, the positional relationship between the housing assembly 1 and the stator assembly 2 can be uniquely determined. Since the housing 102 and the stator assembly 2 are clearance-fitted, two or more positioning ribs 7 can be provided to make the connection between the two more firmly and prevent the housing 102 and the stator assembly 2 from sliding relative to each other. In this embodiment, two positioning ribs 7 are provided, and the positioning ribs 7 protrude from the inner surface of the housing 102.

[0073] like Fig.10 As shown, the positioning rib 7 preferably extends to both ends of the housing 102 along the axial direction of the housing 102, and the positioning groove 8 can be located only at the end of the stator assembly 2 to play a guiding and positioning role. During installation, the positioning groove 8 at one end is inserted into the positioning rib 7, and then the stator assembly 2 is completely installed into the housing 102 along the positioning rib 7. It is preferred to process chamfers 701 at both ends of the positioning rib 7, so that the stator assembly 2 has a good guiding and stabilizing effect when assembling, which is convenient for rapid assembly.

[0074] The second asymmetric positioning mechanism comprises:

[0075] like Fig.13 and Fig.14 As shown, two or more rivet posts 9 are fixed at one end of the stator assembly 2 and arranged in a non-center-symmetric and non-circular array with respect to the stator assembly 2; riveting holes 10 are opened on the circuit board 4 and correspondingly cooperate with the rivet posts 9. Similar to the arrangement principle of the first asymmetric positioning mechanism, the number of rivet posts 9 is also divided into an even number and an odd number. When the non-center-symmetric arrangement corresponds to an even number of rivet posts 9, the above arrangement can ensure that the relative angle between the Hall element installed on the circuit board 4 and the pole teeth of the stator core is installed correctly.

[0076] The rivet hole 10 and the rivet post 9 can be connected by hot riveting, that is, the rivet post 9 is heated by hot air to soften the connection part, and then pressure is applied to connect the circuit board 4 and the rivet post 9 together. Compared with the traditional fixing with the first screw 11, this connection method is simple to operate, firmly installed, and can withstand greater external force.

[0077] The rivet holes 10 and the rivet studs 9 can also be interlocked, such as Fig.15As shown, the rivet column 9 includes a riveting portion 901 and a limiting portion 902. The end of the limiting portion 902 forms a limiting surface 903 that abuts against the circuit board 4. The riveting portion 901 is a buckle 904 that is inserted into the riveting hole 10. The buckle 904 is engaged in the riveting hole 10 to achieve the connection between the two. After the buckle 904 is connected, hot riveting can also be used for further fixing.

[0078] The inner rotor brushless motor of this embodiment can be applied to the field of servo motor drive and control integrated system.

[0079] Embodiment 3

[0080] Based on the second embodiment, Fig. 9 , Fig.11 and Fig.12 As shown, the inner wall of the housing 102 has a first guide groove 12 corresponding to the screw 16, and a boss 13 is formed on the outer wall corresponding to the first guide groove 12. The outer wall of the stator assembly 2 has a second guide groove 14 directly opposite to the first guide groove 12. The first guide groove 12 and the second guide groove 14 form a slot for the screw 16 to pass through. In a conventional motor, the hole on the housing 102 for the screw 16 to pass through is located inside the wall of the housing 102, and is not connected to the inner surface and the outer surface of the housing 102. Therefore, the thickness of the conventional housing 102 is inconsistent in the circumferential direction, and the uniform strength cannot be guaranteed.

[0081] In this embodiment, the first guide groove 12 is processed from the inner wall of the casing 102, and the material at the first guide groove 12 is extruded to the outside of the casing 102 to form a boss 13, so that the thickness of the casing 102 in the circumferential direction remains consistent, and the inner surface of the casing 102 has no protruding structure and is still a circular surface. The cross-section of the first guide groove 12 forms more than a semicircle, and most of the structure of the screw 16 is located in the first guide groove 12, and only a small part is located in the second guide groove 14. The screw 16 between the first guide groove 12 and the second guide groove 14 can also strengthen the connection strength between the casing 102 and the stator assembly 2.

[0082] The inner rotor brushless motor of this embodiment can be applied to the field of servo motor drive and control integrated system.

[0083] In the description of the present invention, it is necessary to understand that the terms "front", "rear", "inside", "outside", "axial", "radial", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0084] Furthermore, the terms “first”, “second”, etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0085] In this specification, the schematic representation of the terms does not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in one or more embodiments.

[0086] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An inner rotor brushless motor that is easy to dissipate heat, characterized in that: include: Housing assembly (1); A stator assembly (2) is installed in the housing assembly (1); A rotor assembly (3) is located inside the stator assembly (2), with two ends penetrating the housing assembly (1) and being rotatably connected to the housing assembly (1); The fan (5) is located outside the housing assembly (1) and is mounted on the output end of the rotor assembly (3). The fan (5) comprises a chassis (501) and a plurality of fan blades (502) mounted on one end of the chassis (501). A wind-gathering inclined surface (5011) is provided on a side of the chassis (501) facing the housing assembly (1). The distance between the wind-gathering inclined surface (5011) and the housing assembly (1) decreases as the radial dimension increases.

2. The inner rotor brushless motor for facilitating heat dissipation according to claim 1, characterized in that: The wind-gathering inclined surface (5011) is a plane, and the included angle a between the wind-gathering inclined surface (5011) and the end surface of the fan (5) is in the range of 20° to 40°.

3. The inner rotor brushless motor with convenient heat dissipation according to claim 1, characterized in that: The chassis (501) further comprises an upper plane (5012) and a lower plane (5013) which are not in the same plane, the wind gathering inclined surface (5011) is connected via the upper plane (5012) and the lower plane (5013), the upper plane (5012) and the lower plane (5013) are parallel to the end surface of the fan (5), and the distance between the upper plane (5012) and the housing assembly (1) is relatively close.

4. The inner rotor brushless motor for heat dissipation according to claim 3, characterized in that: An annular cylinder (5014) is provided at the center of the chassis (501), the annular cylinder (5014) being connected to the lower plane (5013), a metal sleeve (6) being installed in the annular cylinder (5014), and the metal sleeve (6) being connected to the output shaft of the rotor assembly (3).

5. The inner rotor brushless motor for facilitating heat dissipation according to claim 3, characterized in that: The chassis (501) and the fan blades (502) are both made of plastic material, and the metal sleeve (6) is made of aluminum or copper material.

6. The inner rotor brushless motor for facilitating heat dissipation according to claim 3, characterized in that: The height difference between the upper plane (5012) and the lower plane (5013) is 2 mm to 2.5 mm.

7. The inner rotor brushless motor for facilitating heat dissipation according to claim 4, characterized in that: The outer peripheral surface of the metal sleeve (6) has a grid knurling pattern, and the metal sleeve (6) and the fan (5) are injection molded as one piece.

8. The inner rotor brushless motor for facilitating heat dissipation according to claim 1, characterized in that: The outer peripheral surface of the housing assembly (1) is provided with a plurality of heat dissipation ribs (17).

9. The inner rotor brushless motor for facilitating heat dissipation according to claim 1, characterized in that: The stator assembly (2) and the housing assembly (1) are clearance-matched, the motor further comprising a circuit board (4) and a positioning assembly, the circuit board (4) being mounted at one end of the stator assembly (2) and sleeved on the outside of the rotor assembly (3), the positioning assembly comprising a first asymmetric positioning mechanism arranged between the stator assembly (2) and the housing assembly (1) and a second asymmetric positioning mechanism arranged between the stator assembly (2) and the circuit board (4), so that the circuit board (4), the stator assembly (2) and the housing assembly (1) form a unique connection relationship.

10. The inner rotor brushless motor for facilitating heat dissipation according to claim 9, characterized in that: The first asymmetric positioning mechanism comprises: Two or more positioning ribs (7) are fixed to the inner wall of the shell component (1) and are arranged in a non-centrosymmetric and non-circular array with respect to the shell component (1); A positioning groove (8) is provided on the outer wall of the stator assembly (2) and corresponds to the positioning rib (7); The second asymmetric positioning mechanism comprises: Two or more rivet posts (9) are fixed to one end of the stator assembly (2) and are arranged in a non-centrosymmetric and non-circular array with respect to the stator assembly (2); The riveting holes (10) are formed on the circuit board (4) and correspond to the rivet posts (9).

11. The inner rotor brushless motor for facilitating heat dissipation according to claim 10, characterized in that: The housing assembly (1) comprises a rear end cover (101), a housing (102) and a front end cover (103); the rear end cover (101) and the front end cover (103) are fixed by screws (16); the positioning rib (7) extends axially to both ends of the housing (102); and both ends of the positioning rib (7) are processed with chamfers (701).

12. The inner rotor brushless motor for facilitating heat dissipation according to claim 11, characterized in that: The inner wall of the housing (102) has a first guide groove (12) corresponding to the screw (16) one by one, and a convex column (13) is formed on the outer wall corresponding to the first guide groove (12). The outer wall of the stator assembly (2) has a second guide groove (14) directly opposite to the first guide groove (12), and the first guide groove (12) and the second guide groove (14) form a slot hole for the screw (16) to pass through.

13. The inner rotor brushless motor with convenient heat dissipation according to claim 10, characterized in that: The riveting hole (10) and the rivet column (9) are connected by hot riveting.

14. The inner rotor brushless motor for facilitating heat dissipation according to claim 11, characterized in that: The housing (102) is formed by extrusion of aluminum profiles.

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