Rotor assembly and brushless motor

Abstract

The utility model relates to the technical field of motors, and discloses a rotor assembly and a brushless motor, and the rotor assembly comprises a housing, a magnet protection structure and a plurality of magnets. The shell is provided with an accommodating cavity; the magnet protection structure comprises a first magnet seat and a second magnet seat which are oppositely arranged on the side walls of the two ends in the containing cavity in the axial direction. The first magnet seat and the second magnet seat are oppositely provided with a first limiting structure and a second limiting structure respectively. The magnets are arranged on the side wall of the containing cavity in the axial direction of the containing cavity, and the two opposite ends of each magnet are clamped to the first limiting structure and the second limiting structure respectively. In the radial direction of the shell, the thickness of the first limiting structure and / or the second limiting structure is larger than that of the magnet. The rotor assembly provided by the utility model avoids the problem that the stator assembly collides with the magnets due to radial deviation, thereby ensuring the normal operation of the motor.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a rotor assembly and a brushless motor. Background Technology

[0002] A brushless motor is a type of brushless permanent magnet DC motor. It achieves commutation through electronic control, eliminating the need for mechanical brushes and commutators. Compared to brushed motors, brushless motors offer higher efficiency, longer lifespan, lower noise, and higher operating speeds. The working principle of a brushless DC motor is based on electromagnetic induction and the Lorentz force principle. When current passes through the stator coils, a rotating magnetic field is generated. The permanent magnets in the rotor experience the Lorentz force in this rotating magnetic field, causing the rotor to rotate following the stator magnetic field. The controller achieves commutation of the motor by controlling the current and magnetic field.

[0003] In existing technology, brushless motors consist of a housing, a stator assembly, and a rotor assembly. The stator and rotor assemblies are installed inside the housing, with the rotor assembly passing through the stator assembly. Magnets are located on the inner wall of the housing to generate a magnetic field inside the motor. This magnetic field interacts with the coils of the stator assembly, thereby driving the motor to rotate. However, when the motor is dropped, the stator assembly experiences radial displacement and is highly susceptible to colliding with the magnets, leading to the motor malfunctioning. Utility Model Content

[0004] To address the shortcomings of the prior art, this invention provides a rotor assembly and a brushless motor, which avoids the problem of collision with magnets caused by radial offset of the stator assembly, thereby ensuring the normal operation of the motor.

[0005] The technical effects to be achieved by this utility model are realized through the following aspects:

[0006] In a first aspect, this utility model provides a rotor assembly, comprising:

[0007] The shell has a receiving cavity;

[0008] The magnetic protection structure includes a first magnetic seat and a second magnetic seat disposed opposite to each other on the axially aligned sidewalls within the accommodating cavity. The first magnetic seat and the second magnetic seat are respectively provided with a first limiting structure and a second limiting structure.

[0009] Several magnets are disposed on the side wall of the accommodating cavity along the axial direction of the accommodating cavity, and the opposite ends of the magnets are respectively engaged with the first limiting structure and the second limiting structure;

[0010] In the radial direction of the housing, the thickness of the first limiting structure and / or the second limiting structure is greater than the thickness of the magnet.

[0011] In some implementations, the first magnet seat further includes a first annular seat connected to the side wall or bottom wall of the accommodating cavity. The first annular seat is coaxially arranged with the accommodating cavity. The first limiting structure includes a plurality of first limiting blocks spaced apart along the circumference of the accommodating cavity on the side wall of the first annular seat. Two adjacent first limiting blocks and the first annular seat together form a first limiting groove. The first end of the magnet is located in the first limiting groove.

[0012] In this implementation, two adjacent first limiting blocks and the first annular seat together form a first limiting groove. The first ends of several magnets are correspondingly engaged in several first limiting grooves to limit the first ends of several magnets on the first magnet seat and abut against the side wall of the accommodating cavity.

[0013] In some implementations, the second magnet seat further includes a second annular seat connected to the side wall of the accommodating cavity. The second annular seat is coaxially arranged with the accommodating cavity. The second limiting structure includes a plurality of second limiting blocks spaced apart along the circumference of the accommodating cavity on the side wall of the second annular seat. Two adjacent second limiting blocks and the second annular seat together form a second limiting groove. The second end of the magnet is located in the second limiting groove.

[0014] In some implementations, the first limiting block and / or the second limiting block are configured as fan-shaped rings, and the angle of the central angle corresponding to the arc side of the first limiting block and / or the second limiting block is less than or equal to the angle between the two sides of the first limiting block and / or the second limiting block.

[0015] In this implementation, since the angle of the central angle is less than or equal to the angle between the two sides of the first limiting block and / or the second limiting block, the magnet can more easily enter the first limiting groove and / or the second limiting groove when it is installed, thereby improving the assembly efficiency.

[0016] In some implementations, the first limiting block and / or the second limiting block abut against the sidewall of the accommodating cavity.

[0017] In some implementations, a gap is formed between the first annular seat and the sidewall of the accommodating cavity.

[0018] In this implementation, when assembling the motor, glue or an adhesive layer needs to be applied to the inside of the accommodating cavity. Since there is a gap between the first annular seat and the side wall of the accommodating cavity, the first annular seat is prevented from scraping against the glue or adhesive layer when the first magnet seat is installed into the accommodating cavity. Thus, when installing the magnet, it is not necessary to apply glue or add an adhesive layer again, so that the magnet can be adhered to the side wall of the accommodating cavity, thereby improving the overall assembly efficiency.

[0019] In some implementations, the side of the first annular seat facing away from the first limiting block is provided with a support member that abuts against the bottom wall of the accommodating cavity.

[0020] Secondly, this utility model provides a brushless motor, including a stator assembly and the aforementioned rotor assembly. The stator assembly includes a base installed in the accommodating cavity, and the rotor assembly further includes a rotating shaft passing through the base. The shaft of the housing is sleeved on the rotating shaft.

[0021] In some implementations, the brushless motor further includes a circuit board, the stator assembly further includes an iron core and a coil, the iron core is sleeved on the base, the coil is wound around the iron core, and the circuit board is electrically connected to the coil.

[0022] In some implementations, the brushless motor further includes a lead plate, which is disposed between the coil and the circuit board. The lead plate has a clearance hole, through which the lead wire of the coil passes and is electrically connected to the circuit board.

[0023] In summary, this utility model has at least the following advantages:

[0024] The rotor assembly provided by this utility model has a housing with an accommodating cavity. A first magnet seat and a second magnet seat are installed on the side walls of opposite ends in the axial direction within the accommodating cavity. The first magnet seat has a first limiting structure, and the second magnet seat has a second limiting structure arranged opposite to the first magnet seat. The first limiting structure and the second limiting structure are respectively used to limit the two ends of a plurality of magnets on the side walls of the accommodating cavity, thereby improving the connection stability between the magnets and the housing. The thickness of the first limiting seat and / or the second limiting seat is greater than the thickness of the magnet. Therefore, when the motor falls, it avoids the problem of collision with the magnets due to radial displacement of the stator assembly, thus ensuring the normal operation of the motor. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the rotor assembly in Example 1;

[0026] Figure 2 for Figure 1 The diagram shows the structure of the first limiting structure and the magnet.

[0027] Figure 3 for Figure 1 The diagram shows the structure of the first limiting structure and the second limiting structure.

[0028] Figure 4 This is a schematic diagram of the rotor assembly in Example 2;

[0029] Figure 5 for Figure 4A schematic diagram of the included angle between the two sides of the first limiting block and / or the second limiting block;

[0030] Figure 6 This is a schematic diagram of the structure in Embodiment 2 where a gap is formed between the first annular seat and the side wall of the accommodating cavity;

[0031] Figure 7 This is a schematic diagram of the support structure in Example 2;

[0032] Figure 8 This is a schematic diagram of the brushless motor in Example 3.

[0033] Marked in the image:

[0034] 1. Rotor assembly;

[0035] 10. Shell; 11. Receiving cavity;

[0036] 20. Magnet protection structure; 21. First magnet base; 211. First limiting structure; 2111. First limiting block; 2112. First limiting groove; 212. First annular seat; 2121. Support member; 22. Second magnet base; 221. Second limiting structure; 2211. Second limiting block; 2212. Second limiting groove; 222. Second annular seat;

[0037] 30. Magnet;

[0038] 40. Shaft;

[0039] 2. Brushless motor;

[0040] 50. Stator assembly; 51. Base; 52. Iron core; 53. Coil;

[0041] 60. Circuit board;

[0042] 70. Cable exit plate; 71. Clearance hole. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of this utility model.

[0044] 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 claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0045] Example 1:

[0046] Please see the appendix Figure 1 ~Appendix Figure 3 The rotor assembly 1 of this utility model includes a housing 10, a magnet protection structure 20, and a plurality of magnets 30.

[0047] In this regard, please combine Figure 1 and Figure 2 , Figure 1 The diagram illustrates the structural relationship between the shell 10, the magnetic protective structure 20, and the plurality of magnets 30 in an embodiment of this utility model. Figure 2 The diagram illustrates the structural relationship between the first limiting structure 211 and the magnet 30 in this embodiment of the present invention. Specifically, the housing 10 has a receiving cavity 11; the magnet protection structure 20 includes a first magnet seat 21 and a second magnet seat 22 disposed opposite to each other on the axially aligned sidewalls within the receiving cavity 11, with the first magnet seat 21 and the second magnet seat 22 respectively provided with the first limiting structure 211 and the second limiting structure 221; a plurality of magnets 30 are disposed along the axial direction of the receiving cavity 11 on the sidewalls of the receiving cavity 11, with the opposite ends of the magnets 30 respectively engaged with the first limiting structure 211 and the second limiting structure 221. In the radial direction of the housing 10, the thickness of the first limiting structure 211 and / or the second limiting structure 221 is greater than the thickness of the magnets 30.

[0048] In this embodiment, the first magnet seat 21 and the second magnet seat 22 are mounted on the sidewalls of opposite ends in the axial direction within the accommodating cavity 11 of the housing 10. The first magnet seat 21 is provided with a first limiting structure 211, and the second magnet seat 22 is provided with a second limiting structure 221. The second limiting structure 221 and the first limiting structure 211 are arranged opposite to each other. A plurality of magnets 30 are arranged along the axial direction of the accommodating cavity 11 on the sidewall of the accommodating cavity 11, and the first end of the plurality of magnets 30 is engaged with the first limiting structure 211, and the second end of the magnets 30 is engaged with the second limiting structure 221. Positioning structure 221, first magnet seat 21 and second magnet seat 22 respectively limit the opposite ends of magnet 30 to the side wall of the receiving cavity 11 of housing 10, thereby improving the connection stability between magnet 30 and housing 10; and the thickness of first limiting structure 211 and / or second limiting structure 221 is greater than the thickness of magnet 30, thus avoiding the problem that when the motor falls, the stator assembly 50 will undergo radial displacement and collide with magnet 30, thereby preventing the motor from working properly, thus ensuring the reliability of the motor.

[0049] The rotor assembly 1 described above has a housing 10 with a receiving cavity 11. A first magnet seat 21 and a second magnet seat 22 are installed on the side walls of opposite ends in the axial direction within the receiving cavity 11. The first magnet seat 21 has a first limiting structure 211, and the second magnet seat 22 has a second limiting structure 221 that is opposite to the first magnet seat 21. The first limiting structure 211 and the second limiting structure 221 are respectively used to limit the two ends of a plurality of magnets 30 on the side walls of the receiving cavity 11, thereby improving the connection stability between the magnets 30 and the housing 10. The thickness of the first limiting seat and / or the second limiting seat is greater than the thickness of the magnets 30. Therefore, when the motor falls, it avoids the problem of collision between the stator assembly 50 and the magnets 30 due to radial displacement, thereby ensuring the normal operation of the motor.

[0050] In some preferred embodiments, please refer to Figure 3 , Figure 3 The diagram illustrates the structural relationship between the first annular seat 212 and the first limiting block 2111 in this embodiment of the present invention. Specifically, the first magnet seat 21 further includes a first annular seat 212 connected to the side wall or bottom wall of the receiving cavity 11. The first annular seat 212 is coaxially arranged with the receiving cavity 11. The first limiting structure 211 includes a plurality of first limiting blocks 2111 spaced apart along the circumference of the receiving cavity 11 on the side wall of the first annular seat 212. Two adjacent first limiting blocks 2111 and the first annular seat 212 together form a first limiting groove 2112, and the first end of the magnet 30 is located in the first limiting groove 2112. Two adjacent first limiting blocks 2111 and the first annular seat 212 together form the first limiting groove 2112. The first ends of the plurality of magnets 30 are correspondingly engaged in the plurality of first limiting grooves 2112 to limit the first ends of the plurality of magnets 30 on the first magnet seat 21 and abut against the side wall of the receiving cavity 11. The first limiting block 2111 is arranged at intervals along the circumference of the accommodating cavity 11 on the side wall of the first annular seat 212, so that a number of magnets 30 are distributed at intervals along the circumference of the accommodating cavity 11, thereby improving the reliability of the overall structure.

[0051] Preferably, the first annular seat 212 is connected to the side wall and bottom wall of the accommodating cavity 11, thereby improving the connection stability between the first magnet seat 21 and the housing 10, making the overall structure more compact. A plurality of limiting blocks are evenly spaced along the circumference of the accommodating cavity 11 on the side wall of the first annular seat 212, so that a plurality of magnets 30 are evenly spaced along the circumference of the accommodating cavity 11 on the side wall of the accommodating cavity 11, thereby improving the reliability of the motor.

[0052] In some more preferred embodiments, the second magnet seat 22 further includes a second annular seat 222 connected to the side wall of the receiving cavity 11. The second annular seat 222 is coaxially arranged with the receiving cavity 11. The second limiting structure 221 includes a plurality of second limiting blocks 2211 spaced apart along the circumference of the receiving cavity 11 on the side wall of the second annular seat 222. Two adjacent second limiting blocks 2211 and the second annular seat 222 together form a second limiting groove 2212. The second end of the magnet 30 is located in the second limiting groove 2212. Two adjacent second limiting blocks 2211 and the second annular seat 222 together form the second limiting groove 2212. The second ends of the plurality of magnets 30 are correspondingly engaged in the plurality of second limiting grooves 2212 to limit the second ends of the plurality of magnets 30 on the second magnet seat 22 and abut against the side wall of the receiving cavity 11. The second limiting groove 2212 and the first limiting groove 2112 work together to limit the magnet 30 as a whole on the side wall of the accommodating cavity 11, thereby ensuring the connection stability between the magnets 30 and the housing 10, and avoiding the problem that the magnets 30 will become loose during the rotation of the housing 10 when the motor is working, which would cause them to rub against the stator assembly 50.

[0053] Example 2:

[0054] The difference between this embodiment and Embodiment 1 is that this embodiment further optimizes the structure of the rotor assembly 1 of this utility model. Please refer to the appendix. Figure 4 ~Appendix Figure 7 .

[0055] In this regard, please combine Figure 4 and Figure 5 , Figure 4 and Figure 5 The diagram illustrates the positional relationship between the central angle R1 and the included angle R2 in this embodiment of the invention. Specifically, the first limiting block 2111 and / or the second limiting block 2211 are configured as a fan-shaped ring, and the angle of the central angle R1 corresponding to the arc side of the first limiting block 2111 and / or the second limiting block 2211 is less than or equal to the angle R2 between the two sides of the first limiting block 2111 and / or the second limiting block 2211.

[0056] In this embodiment, since the angle of the central angle R1 is less than or equal to the angle R2 between the two sides of the first limiting block 2111 and / or the second limiting block 2211, the magnet 30 is more likely to enter the first limiting groove 2112 and / or the second limiting groove 2212 when it is installed, thereby improving the assembly efficiency.

[0057] It can be understood that the side of the first limiting block 2111 and / or the second limiting block 2211 away from the axis of the housing 10 is an arc edge, and the two sides of the first limiting block 2111 and / or the second limiting block 2211 refer to the two opposite sides connecting the arc edge.

[0058] In some preferred embodiments, the first limiting block 2111 and / or the second limiting block 2211 abut against the sidewall of the accommodating cavity 11. This results in better connection stability between the first magnet seat 21 and the housing 10, and / or between the second magnet seat 22 and the housing 10, and makes the overall structure more compact.

[0059] In some preferred embodiments, please refer to Figure 6 , Figure 6 The diagram illustrates the structural relationship between the first annular seat 212 and the sidewall of the receiving cavity 11 in this embodiment of the invention. Specifically, a gap is formed between the first annular seat 212 and the sidewall of the receiving cavity 11. When assembling the motor, glue or an adhesive layer needs to be applied to the inside of the receiving cavity 11. Because a gap is formed between the first annular seat 212 and the sidewall of the receiving cavity 11, the first annular seat 212 is prevented from scraping against the glue or adhesive layer when the first magnet seat 21 is installed into the receiving cavity 11. Thus, when installing the magnet 30, it is not necessary to apply glue or add an adhesive layer again, so that the magnet 30 can be adhered to the sidewall of the receiving cavity 11, thereby improving the overall assembly efficiency.

[0060] In some more preferred embodiments, please refer to Figure 7 , Figure 7 The diagram illustrates the structural relationship between the first annular seat 212 and the support member 2121 in this embodiment of the present invention. Specifically, the side of the first annular seat 212 facing away from the first limiting block 2111 is provided with a support member 2121 that abuts against the bottom wall of the accommodating cavity 11. This ensures that the first annular seat 212 is more securely installed in the accommodating cavity 11, avoiding the problem of the first annular seat 212 becoming loose during motor operation, thereby making the overall structure more compact.

[0061] Example 3:

[0062] This embodiment, based on the above embodiments, provides a brushless motor 2. Please refer to the appendix. Figure 8 .

[0063] A brushless motor 2 includes a stator assembly 50 and a rotor assembly 1.

[0064] The stator assembly 50 includes a base 51 installed in the accommodating cavity 11, and the rotor assembly 1 also includes a rotating shaft 40, which passes through the base 51, and the shaft of the housing 10 is sleeved on the rotating shaft 40.

[0065] In this embodiment, the base 51 of the stator assembly 50 is installed in the receiving cavity 11 of the housing 10. The housing 10 protects the stator assembly 50 and avoids the stator assembly 50 from rubbing against external equipment. The rotating shaft 40 passes through the base 51, and the housing 10 is sleeved on the rotating shaft 40. The rotation of the rotating shaft 40 drives the housing 10 to rotate relative to the base 51, thereby ensuring the reliability of the brushless motor 2.

[0066] In some preferred embodiments, the brushless motor 2 further includes a circuit board 60, and the stator assembly 50 further includes an iron core 52 and a coil 53. The iron core 52 is sleeved on the base 51, and the coil 53 is wound around the iron core 52. The circuit board 60 is electrically connected to the coil 53. When the coil 53 is energized, it generates a magnetic field, which interacts with the magnet 30, thereby driving the brushless motor 2 to rotate, ensuring the reliability of the overall structure.

[0067] In some more preferred embodiments, the brushless motor 2 further includes a lead plate 70, which is disposed between the coil 53 and the circuit board 60. The lead plate 70 has a clearance hole 71, through which the lead wire of the coil 53 passes and is electrically connected to the circuit board 60. The lead wire of the coil 53 passes through the clearance hole 71 of the lead plate 70 and is electrically connected to the circuit board 60, so as to make the overall structure more compact.

[0068] The brushless motor 2 of this utility model has a housing 10 with a receiving cavity 11. A first magnet seat 21 and a second magnet seat 22 are installed on the side walls of opposite ends in the axial direction within the receiving cavity 11. The first magnet seat 21 is provided with a first limiting structure 211, and the second magnet seat 22 is provided with a second limiting structure 221 opposite to the first magnet seat 21. The first limiting structure 211 and the second limiting structure 221 are respectively used to limit the two ends of a plurality of magnets 30 on the side walls of the receiving cavity 11, thereby improving the connection stability between the magnets 30 and the housing 10. The thickness of the first limiting seat and / or the second limiting seat is greater than the thickness of the magnets 30. Therefore, when the motor falls, it avoids the problem of collision with the magnets 30 due to radial displacement of the stator assembly 50, thereby ensuring the normal operation of the motor.

[0069] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0070] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0071] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0072] In this invention, unless otherwise expressly specified and limited, "above or below" the first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0073] Although the description of this utility model has been given in conjunction with the specific embodiments described above, it is obvious to those skilled in the art that many substitutions, modifications, and variations can be made based on the above description. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A rotor assembly characterized by, The application relates to a shell (10) provided with a containing cavity (11), a magnet protection structure (20) and a plurality of magnets (30). The magnet protection structure (20) comprises a first magnet seat (21) and a second magnet seat (22) oppositely arranged on the two end side walls of the containing cavity (11) in the axial direction, and the first magnet seat (21) and the second magnet seat (22) are oppositely provided with a first limiting structure (211) and a second limiting structure (221) respectively. The magnets (30) are arranged on the side wall of the containing cavity (11) in the axial direction of the containing cavity (11), and the opposite ends of the magnets (30) are clamped on the first limiting structure (211) and the second limiting structure (221) respectively. In the radial direction of the shell (10), the thickness of the first limiting structure (211) and / or the second limiting structure (221) is greater than the thickness of the magnet (30). The first magnet seat (21) further comprises a first annular seat (212) connected to the side wall or the bottom wall of the containing cavity (11), the first annular seat (212) is coaxially arranged with the containing cavity (11), the first limiting structure (211) comprises a plurality of first limiting blocks (2111) arranged on the side wall of the first annular seat (212) in the circumferential direction, and two adjacent first limiting blocks (2111) and the first annular seat (212) jointly form a first limiting groove (2112), and the first end of the magnet (30) is located in the first limiting groove (2112).

2. The rotor assembly of claim 1, wherein The second magnet seat (22) further comprises a second annular seat (222) connected to the side wall of the containing cavity (11), the second annular seat (222) is coaxially arranged with the containing cavity (11), the second limiting structure (221) comprises a plurality of second limiting blocks (2211) arranged on the side wall of the second annular seat (222) in the circumferential direction, and two adjacent second limiting blocks (2211) and the second annular seat (222) jointly form a second limiting groove (2212), and the second end of the magnet (30) is located in the second limiting groove (2212).

3. The rotor assembly of claim 1, wherein The first limiting block (2111) is arranged in a fan ring shape, and the angle of the central angle corresponding to the arc-shaped side of the first limiting block (2111) is less than or equal to the angle of the included angle between the two side edges of the first limiting block (2111).

4. The rotor assembly of claim 2, wherein The second limiting block (2211) is arranged in a fan ring shape, and the angle of the central angle corresponding to the arc-shaped side of the second limiting block (2211) is less than or equal to the angle of the included angle between the two side edges of the second limiting block (2211).

5. The rotor assembly of claim 3, wherein The first limiting block (2111) abuts against the side wall of the containing cavity (11).

6. The rotor assembly of claim 2, wherein The second limiting block (2211) abuts against the side wall of the containing cavity (11).

7. The rotor assembly of claim 3, wherein A gap is formed between the first annular seat (212) and the side wall of the containing cavity (11).

8. The rotor assembly of claim 2, wherein The side of the first annular seat (212) away from the first limiting block (2111) is provided with a supporting piece (2121) abutting against the bottom wall of the containing cavity (11).

9. The rotor assembly of claim 2, wherein, ​ 10. A brushless electric motor characterized by The brushless motor (2) comprises a stator assembly (50) and the rotor assembly (1) in any one of claims 1 to 9, the stator assembly (50) comprises a base (51) installed in the accommodating cavity (11), the rotor assembly (1) further comprises a rotating shaft (40), the rotating shaft (40) penetrates the base (51), and the shaft center of the shell (10) is sleeved on the rotating shaft (40).

11. The brushless motor of claim 10, wherein, The brushless motor (2) further comprises a circuit board (60), the stator assembly (50) further comprises an iron core (52) and a coil (53), the iron core (52) is sleeved on the base (51), the coil (53) is wound on the iron core (52), and the circuit board (60) is electrically connected with the coil (53).

12. The brushless motor of claim 11, wherein, The brushless motor (2) further comprises a wire outlet plate (70), the wire outlet plate (70) is arranged between the coil (53) and the circuit board (60), the wire outlet plate (70) is provided with a position avoiding hole (71), and the lead wire of the coil (53) penetrates the position avoiding hole (71) and is electrically connected with the circuit board (60).

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