Brushless motor and power tool

Abstract

The utility model discloses a kind of brushless motor and electric tool, it is related to motor technical field, wherein, brushless motor includes shell and the rotor assembly and stator assembly being arranged in the shell;The rotor assembly includes rotor core, riveting piece and the balance block being arranged in the rotor core along its axial direction both ends, the balance block has first mounting hole;The riveting piece includes installation part, the installation part has top surface and abutting surface along the both sides of the rotor core axial direction, the distance between the top surface and the abutting surface gradually decreases from the middle part of the top surface towards the edge of the installation part;The utility model provides technical scheme for by using the distance between top surface and abutting surface gradually decreases from the middle part of the top surface towards the edge of installation part, increase the deformation variable generated by riveting piece, and then improve the stability of riveting piece and first balance block connection.

Description

Technical Field

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

[0002] A brushless DC motor consists of a motor body and a driver. The driver controls the motor body to perform operations such as starting, stopping, braking, speed adjustment, and protection. When power tools are working, the rotor assembly speed typically reaches tens of thousands of revolutions per minute, generating significant vibrations, especially noticeable in tools such as angle grinders, grooving machines, and cutting machines. Existing rotor assemblies have poor stability; after prolonged use, internal components are prone to detachment, thus affecting the lifespan of the power tool. Utility Model Content

[0003] The main purpose of this invention is to propose a brushless motor and power tool, which aims to improve the stability of the rotor assembly operation.

[0004] To achieve the above objectives, the present invention proposes a brushless motor comprising a housing and a rotor assembly and a stator assembly disposed within the housing; the stator assembly is disposed on the outer periphery of the rotor assembly; the rotor assembly comprises a rotor core, a riveting component, and balance blocks disposed at both ends of the rotor core along its axial direction, the balance blocks having first mounting holes, and two balance blocks being a first balance block and a second balance block; the riveting component is sequentially inserted through the first mounting holes of the first balance block, the rotor core, and the second balance block to rivet and fix the first balance block, the second balance block, and the rotor core; the riveting component includes a mounting portion, the mounting portion having a top surface and an abutment surface on both sides along the axial direction of the rotor core, the abutment surface abutting against the bottom wall and inner side wall of the first mounting hole of the first balance block, the top surface being located on the side of the abutment surface away from the second balance block, the top surface being used for abutment mounting of external devices, and the distance between the top surface and the abutment surface gradually decreasing from the middle of the top surface toward the edge of the mounting portion.

[0005] In one embodiment, the riveting component is a rotary rivet, which is riveted and fixed to the first mounting hole of the first balance block by rotary riveting.

[0006] In one embodiment, the riveting component includes the mounting portion, the connecting section, and the riveting limiting portion connected in sequence. The mounting portion and the riveting limiting portion are respectively disposed in the first mounting hole of the first balance block and the first mounting hole of the second balance block, and the connecting section is respectively disposed in the first mounting hole and the rotor core.

[0007] In one embodiment, the rotor core is provided with a second mounting hole opposite to the first mounting hole, the second mounting hole being arranged along the axial direction of the rotor core, and the connecting section passing through the first mounting hole and the second mounting hole respectively.

[0008] In one embodiment, the rotor assembly further includes a plurality of magnets, and the rotor core has a plurality of mounting slots extending through it along its axial direction. The plurality of mounting slots are arranged circumferentially along the rotor core, and a magnet is installed in one of the mounting slots.

[0009] In one embodiment, the riveting components are provided in multiple ways, the first mounting holes are provided in multiple ways, the multiple first mounting holes are arranged circumferentially along the balance block, and the second mounting holes are provided in multiple ways, the multiple second mounting holes are arranged circumferentially along the rotor core.

[0010] In one embodiment, the rotor core has a third mounting hole for mounting a rotor shaft, a plurality of second mounting holes are arranged around the third mounting hole in a circumferential direction, and a plurality of mounting slots are arranged around the third mounting hole in a circumferential direction, the mounting slots being located on the side of the second mounting hole opposite to the third mounting hole.

[0011] In one embodiment, the first mounting hole on the first balance block includes a first mounting section and a second mounting section connected to each other, the mounting part is disposed in the first mounting section, the connecting section is disposed in the second mounting section, and the outer diameter of the first mounting section is larger than the outer diameter of the second mounting section.

[0012] In one embodiment, the top surface is arc-shaped, and the abutting surface is connected to the inner wall of the first mounting hole of the first balance block by riveting.

[0013] This utility model also proposes an electric tool, including a brushless motor as described in any of the above embodiments.

[0014] The technical solution of this utility model adopts a method in which the distance between the top surface and the abutment surface gradually decreases from the middle of the top surface toward the edge of the mounting part. The edge of the top surface and the abutment surface are respectively interference-fitted with the inner side wall and bottom wall of the first mounting hole of the first balance block, which increases the deformation of the riveting part, so that the mounting part can be more fully filled in the first mounting hole, thereby improving the stability of the connection between the riveting part and the first balance block. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 A schematic diagram of a brushless motor according to an embodiment of the present invention;

[0017] Figure 2 An exploded structural diagram of an embodiment of the brushless motor provided by this utility model;

[0018] Figure 3 A schematic diagram of a riveting component in a brushless motor provided by this utility model;

[0019] Figure 4 A structural cross-sectional view of an embodiment of the rotor assembly in the brushless motor provided by this utility model;

[0020] Figure 5 for Figure 4 A magnified view of a portion of point A in the middle.

[0021] Explanation of icon numbers:

[0022] 1. Rotor assembly; 11. Rotor core; 111. Second mounting hole; 112. Mounting groove; 113. Third mounting hole; 12. Riveting component; 121. Mounting part; 1211. Top surface; 1212. Abutment surface; 122. Connecting section; 123. Riveting limiting part; 13. Balance block; 131. First mounting hole; 1311. First mounting section; 1312. Second mounting section; 132. First balance block; 133. Second balance block; 14. Magnet.

[0023] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0025] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0026] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0027] A brushless DC motor consists of a motor body and a driver. The driver controls the motor body to perform operations such as starting, stopping, braking, speed adjustment, and protection. When power tools are working, the rotor assembly 1 typically rotates at speeds of tens of thousands of revolutions per minute, generating significant vibrations, especially noticeable on tools such as angle grinders, grooving machines, and cutting machines. Currently, the balance block 13 in the rotor assembly 1 is fixed to the rotor core 11 by riveting. This connection method has significant drawbacks: firstly, the rivets deform only slightly during riveting, with deformation occurring only at the contact surface between the rivet and the balance block 13, resulting in insufficient connection strength between the balance block 13 and the rotor core 11; secondly, the contact area between the rivet and the mounting holes of the balance block 13 is small, making it difficult to form a stable mechanical connection. This structure is prone to loosening at high speeds, leading to a decrease in the dynamic balance performance of the rotor assembly 1 and consequently, severe vibrations. After prolonged use, the balance block 13 may shift or even detach, affecting not only the motor's operational stability but also shortening the power tool's lifespan.

[0028] This utility model proposes a brushless motor.

[0029] Please see Figures 1 to 4In one embodiment of this utility model, the brushless motor includes a housing and a rotor assembly 1 and a stator assembly disposed within the housing. The stator assembly is disposed on the outer periphery of the rotor assembly 1. The rotor assembly 1 includes a rotor core 11, riveting members 12, and balance blocks 13 disposed at both ends of the rotor core 11 along its axial direction. Each balance block 13 has a first mounting hole 131, and the two balance blocks 13 are a first balance block 132 and a second balance block 133. The riveting members 12 are sequentially inserted through the first mounting holes 131 of the first balance block 132, the rotor core 11, and the second balance block 133 to rivet and fix the first balance block 132, the second balance block 133, and the rotor core 11. The riveting component 12 includes a mounting portion 121. The mounting portion 121 has a top surface 1211 and an abutment surface 1212 on both sides along the axial direction of the rotor core 11. The abutment surface 1212 abuts against the bottom wall and inner side wall of the first mounting hole 131 of the first balance block 132. The top surface 1211 is located on the side of the abutment surface 1212 away from the second balance block 133. The top surface 1211 is used for abutment installation of external devices. The distance between the top surface 1211 and the abutment surface 1212 gradually decreases from the middle of the top surface 1211 toward the edge of the mounting portion 121.

[0030] The technical solution of this utility model adopts a method in which the distance between the top surface 1211 and the abutment surface 1212 gradually decreases from the middle of the top surface 1211 toward the edge of the mounting part 121. The edge of the top surface 1211 and the abutment surface 1212 are respectively interference-fitted with the inner side wall and bottom wall of the first mounting hole 131 of the first balance block 132, thereby increasing the deformation of the riveting part 12, so that the mounting part 121 can be more fully filled in the first mounting hole 131, thereby improving the stability of the connection between the riveting part 12 and the first balance block 132.

[0031] In this embodiment, the housing can be configured as a support structure enclosing the internal components of the motor. The housing can be die-cast from aluminum alloy, thereby ensuring the structural strength of the housing while better protecting the internal components and assisting in heat dissipation for the internal components of the motor. The rotor assembly 1 includes a rotor core 11 as the magnetic conductor, which can be used to generate a rotating magnetic field. The balance blocks 13 can be configured as counterweight components installed at both ends of the rotor core 11 along the axial direction. The two balance blocks 13 can be configured as a first balance block 132 and a second balance block 133. The balance blocks 13 are used to provide dynamic balance adjustment when the rotor assembly 1 rotates, thereby improving the rotational stability of the rotor core 11. The balance blocks 13 can be manufactured using high-density alloy materials, thereby ensuring the structural strength of the balance blocks 13. The mounting portion 121 on the riveting member 12 can be configured as a riveting area that contacts the balance block 13. The mounting portion 121 can be riveted and fixed to the first mounting hole 131 on the balance block 13 by riveting. The riveting member 12 is sequentially inserted into the first mounting hole 131 of the first balance block 132, the first mounting hole 131 of the rotor core 11 and the first mounting hole 131 of the second balance block 133, thereby realizing the riveting and fixing of the first balance block 132, the second balance block 133 and the rotor core 11, and improving the stability of the connection between the first balance block 132, the second balance block 133 and the rotor core 11. The mounting part 121 has a top surface 1211 and an abutment surface 1212 on both sides along the axial direction of the rotor core 11. The side of the mounting part 121 away from the second balance block 133 can be set as the top surface 1211, and the side of the mounting part 121 near the first balance block 132 can be set as the abutment surface 1212. The top surface 1211 abuts against an external processing device. Under the action of the external processing device, the mounting part 121 rotates rapidly, causing the abutment surface 1212 and the edge of the top surface 1211 to rub against the bottom wall and inner side wall of the first mounting hole 131 of the first balance block 132, respectively, generating heat. This allows the mounting part 121 to be riveted and fixed to the first mounting hole 131 of the first balance block 132. When the external processing device processes the riveted part 12, the external device abuts against the top surface 1211 and drives the riveted part 12 to rotate rapidly. The material of the riveted part 12 is heated and extends outwards, causing the distance between the top surface 1211 and the abutment surface 1212 to gradually decrease from the middle of the top surface 1211 towards the edge of the mounting part 121. This increases the deformation of the riveted part 12, allowing the mounting part 121 to more fully fill the gap in the first mounting hole 131, thereby improving the stability of the connection between the riveted part 12 and the first balance block 132.

[0032] like Figure 3 and Figure 4 As shown, in one embodiment, the riveting member 12 is a rotary rivet, and the riveting member 12 is riveted and fixed to the first mounting hole 131 of the first balance block 132 by rotary riveting.

[0033] In this embodiment, the spin riveting rivet refers to the riveting component 12 riveted by a spin riveting process. During the spin riveting process, the rivet material undergoes plastic deformation and rivets into contact with the inner wall of the first mounting hole 131. This application utilizes the riveting component 12, which, through rotational compression, ensures that the material of the riveting component 12 fully fills the gap in the first mounting hole 131. This improves the problem of component detachment caused by insufficient riveting strength during high-speed operation of the rotor assembly 1, thereby enhancing the connection reliability between the riveting component 12 and the first balance block 132, and extending the service life of the brushless motor.

[0034] like Figure 3 and Figure 4 As shown, in one embodiment, the riveting member 12 includes a mounting part 121, a connecting section 122, and a riveting limiting part 123 connected in sequence. The mounting part 121 and the riveting limiting part 123 are respectively disposed in the first mounting hole 131 of the first balance block 132 and the first mounting hole 131 of the second balance block 133. The connecting section 122 passes through the first mounting hole 131 and the rotor core 11.

[0035] In this embodiment, the mounting portion 121 is the part of the riveting member 12 that mates with the first mounting hole 131 of the first balance block 132. The mounting portion 121 is used to transmit pressure during the riveting process and forms a fixed connection with the bottom wall and inner side wall of the first mounting hole 131 of the first balance block 132. The abutting surface 1212 of the mounting portion 121 abuts against the bottom wall of the first mounting hole 131 of the first balance block 132, and the edge of the top surface 1211 of the mounting portion 121 is press-fitted with the inner side wall of the first mounting hole 131 of the first balance block 132, thereby improving the stability of the connection between the riveting member 12 and the first balance block 132. The connecting section 122 is the middle part connecting the mounting portion 121 and the riveting limiting portion 123. The shape of the connecting section 122 can be set as a rod of equal diameter. The connecting section 122 can be used to penetrate the rotor core 11 and maintain the axial positioning of the rotor core 11. The riveting limiting part 123 is the portion of the riveting part 12 that mates with the first mounting hole 131 of the second balance block 133. The riveting limiting part 123 can be cylindrical in shape. The riveting limiting part 123 can be used to limit the displacement of the riveting part 12 within the second balance block 133, thereby preventing the second balance block 133 from becoming loose after riveting with the rotor core 11. The mounting part 121 is riveted into the first mounting hole 131 of the first balance block 132 by riveting, and the riveting limiting part 123 is assembled into the first mounting hole 131 of the second balance block 133. The connecting section 122 passes through the rotor core 11 and forms an interference fit with the two first mounting holes 131. In the riveting process, under the high-speed rotation of the external device, the gradual distance between the top surface 1211 and the abutment surface 1212 of the mounting part 121 makes the riveting force evenly distributed radially along the mounting part 121, thereby increasing the deformation of the riveting part 12 and improving the stability of the connection between the riveting part 12 and the first balance block 132. During the riveting process, the riveting limiting part 123 is tightly connected to the inner wall of the first mounting hole 131 of the second balance block 133 through plastic deformation, which further restricts the axial displacement of the second balance block 133 and the rotor core 11.

[0036] like Figure 2 As shown, in one embodiment, the rotor core 11 is provided with a second mounting hole 111 opposite to the first mounting hole 131. The second mounting hole 111 is arranged along the axial direction of the rotor core 11, and the connecting segment 122 passes through the first mounting hole 131 and the second mounting hole 111 respectively.

[0037] In this embodiment, along the axial direction of the rotor core 11, the second mounting hole 111 is a through hole on the rotor core 11 corresponding to the position of the first mounting hole 131 on the first balance block 132 or the second balance block 133. Specifically, it can be achieved by drilling or stamping. The axial direction of the second mounting hole 111 is parallel to the axial direction of the rotor core 11, making it easier to align the position of the second mounting hole 111 with the position of the first mounting hole 131 along the axial direction of the rotor core 11. This application provides multiple second mounting holes 111 along the axial direction of the rotor core 11, forming a coaxial correspondence with the first mounting holes 131 on the first balance block 132 or the second balance block 133. During assembly, the connecting section 122 of the riveting component 12 passes sequentially through the first mounting hole 131 of the first balance block 132, the second mounting hole 111 of the rotor core 11, and the first mounting hole 131 of the second balance block 133, thereby enabling the riveting component 12 to form multi-point contact with the rotor core 11, the first balance block 132, and the second balance block 133, thereby improving the connection strength between the rotor core 11 and the first balance block 132 and the second balance block 133.

[0038] like Figure 2 As shown, in one embodiment, the rotor assembly 1 further includes a plurality of magnets 14, and the rotor core 11 is provided with a plurality of mounting slots 112 through it along its axial direction. The plurality of mounting slots 112 are arranged circumferentially along the rotor core 11, and a magnet 14 is installed in a mounting slot 112.

[0039] In this embodiment, the magnet 14 is a magnetic element made of permanent magnet material, specifically neodymium iron boron or ferrite material. The magnet 14 is used to generate a magnetic field when the rotor core 11 rotates. The mounting slot 112 is a through-slot structure formed along the axial direction of the rotor core 11 and is used to accommodate and fix the magnet 14. Multiple mounting slots 112 are evenly distributed around the central axis of the rotor core 11, thereby making the magnetic field formed by the multiple magnets 14 along the circumferential direction of the rotor core 11 more uniform. Multiple magnets 14 are embedded one-to-one into multiple mounting slots 112, and the multiple mounting slots 112 are arranged around the axial direction of the rotor core 11, so that the magnets 14 maintain a fixed position during the rotation of the rotor core 11. This application increases the contact area between the magnet 14 and the rotor core 11 by individually installing each magnet 14 in the corresponding mounting slot 112, and with the help of the first balance block 132 and the second balance block 133 to limit the magnet 14, thereby preventing the magnet 14 from shifting or falling off when rotating at high speed.

[0040] like Figure 2As shown, in one embodiment, the riveting member 12 is provided in multiple ways, the first mounting hole 131 is provided in multiple ways, the multiple first mounting holes 131 are arranged along the circumference of the balance block 13, the second mounting hole 111 is provided in multiple ways, the multiple second mounting holes 111 are arranged along the circumference of the rotor core 11.

[0041] In this embodiment, by increasing the number of riveting members 12, the first balance block 132 and the second balance block 133 are fixed to multiple positions of the rotor core 11, thereby improving the stability of the connection between the first balance block 132 and the second balance block 133 and the rotor core 11. Multiple first mounting holes 131 are evenly distributed in the circumferential direction of the first balance block 132, thereby improving the uniformity of the connection between the first balance block 132 and the rotor core 11. Multiple second mounting holes 111 are distributed around the central axis of the rotor core 11, thereby forming symmetrical support on the rotor core 11 with multiple riveting members 12. Multiple riveting members 12 pass through multiple first mounting holes 131 on the first balance block 132 and multiple second mounting holes 111 on the rotor core 11, thereby forming multiple riveting fixations around the axial direction of the rotor core 11. When the rotor assembly 1 rotates at high speed, multiple rivets 12 can simultaneously withstand centrifugal force, thereby avoiding excessive stress on a single rivet 12 and preventing the first balance block 132 and the second balance block 133 from axially shifting under vibration.

[0042] like Figure 2 As shown, in one embodiment, the rotor core 11 has a third mounting hole 113 for mounting the rotor shaft, a plurality of second mounting holes 111 are arranged around the third mounting hole 113 in the circumferential direction, and a plurality of mounting grooves 112 are arranged around the third mounting hole 113 in the circumferential direction, the mounting grooves 112 being located on the side of the second mounting hole 111 opposite to the third mounting hole 113.

[0043] In this embodiment, the third mounting hole 113 is a shaft hole structure located at the center of the rotor core 11. The third mounting hole 113 can be configured as a cylindrical through hole, used to form an interference fit or clearance fit with the rotor shaft. Multiple second mounting holes 111 are mounting hole structures distributed around the outer periphery of the third mounting hole 113. The second mounting holes 111 can be used to install the connecting section 122 of the riveting component 12. The mounting groove 112 is a rectangular through groove structure distributed around the outer periphery of the third mounting hole 113. By setting the mounting groove 112 to the side of the second mounting hole 111 opposite to the third mounting hole 113, interference with the installation position of the riveting component 12 is avoided. The central axis of the third mounting hole 113 coincides with the rotation axis of the rotor core 11. The second mounting holes 111 are arranged in a circular array around this axis, and the included angle between two adjacent second mounting holes 111 can be set to 30 degrees or 45 degrees. The radius of the annular array distribution of the mounting slot 112 can be larger than the radius of the annular array distribution of the second mounting hole 111, so that the magnet 14 is located on the side of the riveting member 12 away from the third mounting hole 113 after installation, thereby forming a layered structure between the riveting member 12 and the magnet 14 in the radial direction of the rotor core 11. When the connecting section 122 of the riveting member 12 passes through the second mounting hole 111, it will not affect the installation space of the magnet 14.

[0044] like Figure 4 and Figure 5 As shown, in one embodiment, the first mounting hole 131 on the first balance block 132 includes a first mounting section 1311 and a second mounting section 1312 connected to each other. The mounting part 121 is disposed on the first mounting section 1311, and the connecting section 122 is disposed on the second mounting section 1312. The outer diameter of the first mounting section 1311 is larger than the outer diameter of the second mounting section 1312.

[0045] In this embodiment, the first mounting section 1311 is a hole section on the first balance block 132 for accommodating the mounting part 121. The shape of the first mounting section 1311 can adopt a stepped hole structure, and the outer diameter of the first mounting section 1311 is larger than the outer diameter of the second mounting section 1312. The second mounting section 1312 is a hole section for the connecting section 122 to pass through the first balance block 132. The shape of the second mounting section 1312 can adopt a straight hole structure, so that the first mounting hole 131 of the first balance block 132 can adopt a two-section structure with different outer diameters. When the riveted part 12 is riveted and fixed, the mounting part 121 is embedded in the first mounting section 1311, and the connecting section 122 extends through the second mounting section 1312 to the rotor core 11, thereby forming two mounting positions for the riveted part 12 during the installation process. The first mounting section 1311 can provide radial support for the riveted part 12 and the first mounting hole 131 on the first balance block 132, and the second mounting section 1312 can ensure the precise alignment of the connecting section 122 and the rotor core 11.

[0046] like Figures 3 to 5 As shown, in one embodiment, the top surface 1211 is arc-shaped, and the abutment surface 1212 is connected to the inner wall of the first mounting hole 131 by riveting.

[0047] In this embodiment, the external processing device (not shown) may include a drive member and a pressure head. One side of the pressure head is provided with a processing section with a concave spherical surface. The pressure head abuts against the top surface 1211 through the processing section, thereby causing the top surface 1211 to be formed into an arc shape under the processing of the external processing device. The arc shape of the top surface 1211 may be a sphere or a parabolic surface. The portion of the mounting part 121 located on the top surface 1211 is press-fitted with the inner wall of the first mounting hole 131, and the abutment surface 1212 is connected to the inner wall of the first mounting hole 131, increasing the deformation of the mounting part 121, thereby improving the stability of the connection between the riveting part 12 and the first balance block 132.

[0048] This utility model also proposes an electric tool, which includes a brushless motor. The specific structure of the brushless motor is as described in the above embodiments. Since this electric tool adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0049] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A brushless motor, characterized in that, include: Housing and rotor assembly and stator assembly disposed within the housing; The stator assembly is located on the outer periphery of the rotor assembly; The rotor assembly includes a rotor core, riveting components, and balance blocks disposed at both ends of the rotor core along its axial direction. Each balance block has a first mounting hole, and the two balance blocks are a first balance block and a second balance block. The riveting components are sequentially inserted through the first mounting holes of the first balance blocks, the rotor core, and the second balance blocks to rivet and fix the first balance blocks, the second balance blocks, and the rotor core. The riveting components include a mounting portion, which has a top surface and an abutment surface on both sides along the axial direction of the rotor core. The abutment surface abuts against the bottom wall and inner side wall of the first mounting hole of the first balance block. The top surface is located on the side of the abutment surface away from the second balance block and is used for abutment mounting of external devices. The distance between the top surface and the abutment surface gradually decreases from the middle of the top surface toward the edge of the mounting portion.

2. The brushless motor as described in claim 1, characterized in that, The riveting component is a rotary rivet, which is riveted and fixed to the first mounting hole of the first balance block by rotary riveting.

3. The brushless motor as described in claim 2, characterized in that, The riveting component includes the mounting part, the connecting section, and the riveting limiting part connected in sequence. The mounting part and the riveting limiting part are respectively disposed in the first mounting hole of the first balance block and the first mounting hole of the second balance block. The connecting section passes through the first mounting hole and the rotor core respectively.

4. The brushless motor as described in claim 3, characterized in that, The rotor core is provided with a second mounting hole opposite to the first mounting hole. The second mounting hole is arranged along the axial direction of the rotor core, and the connecting section passes through the first mounting hole and the second mounting hole respectively.

5. The brushless motor as described in claim 4, characterized in that, The rotor assembly also includes multiple magnets, and the rotor core has multiple mounting slots through it along its axial direction. The multiple mounting slots are arranged circumferentially along the rotor core, and one magnet is installed in one of the mounting slots.

6. The brushless motor as described in claim 5, characterized in that, The riveting components are provided in multiple ways. The first mounting holes are provided in multiple ways, and the multiple first mounting holes are arranged circumferentially along the balance block. The second mounting holes are provided in multiple ways, and the multiple second mounting holes are arranged circumferentially along the rotor core.

7. The brushless motor as described in claim 6, characterized in that, The rotor core has a third mounting hole for mounting the rotor shaft, a plurality of second mounting holes are arranged around the third mounting hole in the circumferential direction, and a plurality of mounting slots are arranged around the third mounting hole in the circumferential direction, the mounting slots being located on the side of the second mounting hole opposite to the third mounting hole.

8. The brushless motor as described in claim 3, characterized in that, The first mounting hole on the first balance block includes a first mounting section and a second mounting section that are connected to each other. The mounting part is disposed in the first mounting section, and the connecting section is disposed in the second mounting section. The outer diameter of the first mounting section is larger than the outer diameter of the second mounting section.

9. The brushless motor as described in claim 1, characterized in that, The top surface is arc-shaped, and the abutting surface is connected to the inner wall of the first mounting hole of the first balance block by riveting.

10. A power tool, characterized in that, Includes the brushless motor as described in any one of claims 1 to 9.

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