Hollow cup brushless motor

Abstract

The utility model relates to the technical field of motors, and particularly discloses a coreless brushless motor, which comprises a casing, a stator assembly, a rotor assembly and a Hall plate, a first end cover and a second end cover are respectively covered on two openings of a first mounting cavity, a mounting groove is arranged on one surface of the second end cover facing the casing, the stator assembly is arranged in the first mounting cavity, and the Hall plate is arranged in the casing. A second installation cavity is formed in the stator assembly, the rotor assembly is installed in the second installation cavity, the Hall plate comprises an installation plate and a Hall element, the installation plate is inserted into the inner side of the installation groove, and the Hall element is installed on the surface, facing the shell, of the installation plate and used for being electrically connected with an external control element. According to the utility model, the mounting plate and the second end cover are mounted in a plug-in mounting manner without additional connecting parts, so that the mounting space required by the Hall element is effectively reduced, and the overall volume of the coreless brushless motor is further reduced.

Description

Technical Field

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

[0002] Hollow cup brushless motors are DC, permanent magnet, servo micro motors. While inheriting the main design of traditional motors, they adopt a cogless structure, which reduces eddy current losses in the iron core and significantly reduces the weight and moment of inertia of the motor, thereby reducing the mechanical losses of the motor.

[0003] Most coreless brushless motors use Hall effect sensors for drive control. For coreless brushless motors with Hall effect sensors, the position of the Hall plate needs to be adjusted during manufacturing to achieve the optimal commutation position, thereby achieving the best motor performance. To avoid interference between the stator assembly and the Hall plate, which would prevent simple and quick adjustment of the Hall plate in the core, current technology typically threads the Hall plate onto the motor's end cover. This installation method requires reserving space for the screw heads, resulting in increased motor size and cramped internal space. Utility Model Content

[0004] The main purpose of this invention is to propose a hollow cup brushless motor, which aims to solve the problem of the large size and crowded internal space of existing hollow cup brushless motors.

[0005] To solve the above problems, this utility model proposes a hollow cup brushless motor, comprising:

[0006] The housing includes a shell, a first end cover, and a second end cover. The shell forms a first mounting cavity with two openings. The first end cover and the second end cover are respectively fitted onto the two openings of the first mounting cavity. The second end cover has a mounting groove on one surface facing the shell.

[0007] A stator assembly, wherein the stator assembly is mounted in the first mounting cavity, and a second mounting cavity is formed within the stator assembly;

[0008] A rotor assembly, wherein the rotor assembly is mounted in the second mounting cavity, one end of the rotor assembly extends out of the second mounting cavity and the first end cover, and the other end of the rotor assembly extends out of the second mounting cavity and is rotatably connected to the second end cover; and

[0009] A Hall plate, comprising a mounting plate and a Hall element, wherein the mounting plate is inserted into the inner circumferential side of the mounting groove, and the Hall element is mounted on the surface of the mounting plate facing the housing and is used for electrical connection with an external control element.

[0010] In one embodiment, the opening edge of the mounting groove is bendable under external force, the thickness of the mounting plate is less than the depth of the mounting groove, and the opening edge of the mounting groove is bent inward to form a limiting part, which abuts against the surface of the mounting plate facing the housing.

[0011] In one embodiment, the opening edge of the mounting groove is provided with a plurality of limiting portions, each of which abuts against the surface of the mounting plate facing the housing.

[0012] In one embodiment, the outer periphery of the opening edge of the mounting groove is provided with a rounded chamfer, and the rounded chamfer is arranged in a ring shape.

[0013] In one embodiment, the installation gap between the mounting plate and the side wall of the mounting groove is i, where 0.01mm≤i≤0.03mm.

[0014] In one embodiment, the bottom wall of the mounting groove is provided with a receiving groove, the receiving groove and the mounting groove are concentrically arranged, the other end of the rotor assembly passes through the mounting plate and is rotatably connected to the bearing in the receiving groove, and the surface of the mounting plate opposite to the housing abuts against the groove end face of the receiving groove.

[0015] In one embodiment, the second end cap further includes an abutment platform, which is circumferentially disposed on the inner wall of the mounting groove, and the mounting plate abuts against the abutment platform on the surface edge opposite to the housing.

[0016] In one embodiment, the rotor assembly includes a rotating shaft, an annular magnet, a balance ring, a positioning element, and a tracking magnet. The annular magnet is installed in the second mounting cavity, the rotating shaft passes through the annular magnet, one end of the rotating shaft extends out of the first end cover, the other end extends out of the second mounting cavity, and is rotatably connected to the second end cover. The balance ring is sleeved on the rotating shaft and abuts against the end face of the annular magnet facing the first end cover.

[0017] The positioning element is sleeved on the rotating shaft and abuts against the end face of the annular magnet facing the second end cover. The positioning element has a positioning groove, and the tracking magnet is disposed in the positioning groove.

[0018] In one embodiment, the annular magnet is a magnet with two pairs of poles magnetized.

[0019] In one embodiment, the tracking magnet includes four magnet bodies, which are connected end-to-end in a ring in the positioning groove.

[0020] This utility model proposes a hollow cup brushless motor, including a housing, a stator assembly, a rotor assembly, and a Hall plate. The housing includes a shell, a first end cover, and a second end cover. A first mounting cavity is formed inside the housing. The first end cover and the second end cover respectively cover the two openings of the first mounting cavity. A mounting groove is formed on the end of the second end cover facing the shell. The stator assembly is installed in the first mounting cavity, and a second mounting cavity is formed inside the stator assembly. The rotor assembly is installed in the second mounting cavity. One end of the rotor assembly extends out of the second mounting cavity and the first end cover, and the other end of the rotor assembly extends out of the second mounting cavity and is rotatably connected to the second end cover. The Hall plate includes a mounting plate and a Hall element. The mounting plate is snapped into the inner circumference of the mounting groove, and the Hall element is installed on the surface of the mounting plate facing the shell and is used for electrical connection with external control components. This utility model uses an insert method to install the mounting plate and the second end cover, eliminating the need for additional connecting parts, effectively reducing the installation space required inside the motor, and thus reducing the overall size of the hollow cup brushless motor. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of the hollow cup brushless motor of this utility model;

[0023] Figure 2 for Figure 1 A cross-sectional view of the embodiment;

[0024] Figure 3 for Figure 1 Exploded view of the structure in the embodiment;

[0025] Figure 4 for Figure 1 Exploded view of the second end cap and Hall plate in the Chinese embodiment;

[0026] Figure 5 for Figure 1 An exploded view of the rotor assembly in the Chinese embodiment.

[0027] Explanation of icon numbers:

[0028] 100. Hollow cup brushless motor; 10. Housing; 11. Shell; 12. First end cover; 13. Second end cover; 131. Mounting slot; 132. Rounded chamfer; 133. Receiving slot; 134. Abutment platform; 20. Stator assembly; 30. Rotor assembly; 31. Shaft; 32. Ring magnet; 33. Balance ring; 34. Positioning component; 35. Magnet body; 40. Hall plate; 41. Mounting plate; 42. Hall element.

[0029] 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

[0030] 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 protection scope of the present utility model.

[0031] 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 certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0032] 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 indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, 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. If 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.

[0033] Most coreless brushless motors use Hall effect sensors for drive control. For coreless brushless motors with Hall effect sensors, the position of the Hall plate needs to be adjusted during manufacturing to achieve the optimal commutation position, thereby achieving the best motor performance. To avoid interference between the stator assembly and the Hall plate, which would prevent simple and quick adjustment of the Hall plate in the core, current technology typically threads the Hall plate onto the motor's end cover. This installation method requires reserving space for the screw heads, resulting in increased motor size and cramped internal space.

[0034] To address the aforementioned problems, this utility model proposes a hollow cup brushless motor, aiming to solve the issues of large size and cramped internal space in existing hollow cup brushless motors.

[0035] like Figures 1 to 4 In one embodiment, the hollow cup brushless motor 100 includes a housing 10, a stator assembly 20, a rotor assembly 30, and a Hall plate 40. The housing 10 includes a shell 11, a first end cover 12, and a second end cover 13. The shell 11 forms a first mounting cavity with two openings. The first end cover 12 and the second end cover 13 respectively cover the two openings of the first mounting cavity. The second end cover 13 has a mounting groove 131 on one surface facing the shell 11. The stator assembly 20 is mounted in the first mounting cavity, and a second mounting cavity is formed inside the stator assembly 20. The rotor assembly 30 is mounted in the second mounting cavity. One end of the rotor assembly 30 extends out of the second mounting cavity and the first end cover 12, and the other end of the rotor assembly 30 extends out of the second mounting cavity and is rotatably connected to the second end cover 13. The Hall plate 40 includes a mounting plate 41 and a Hall element 42. The mounting plate 41 is inserted into the inner circumferential side of the mounting groove 131, and the Hall element 42 is mounted on the surface of the mounting plate 41 facing the shell 11 and is used for electrical connection with external control elements.

[0036] In this embodiment, the housing 10 is the external protective structure of the hollow cup brushless motor 100. It includes a housing 11, a first end cover 12, and a second end cover 13. The housing 11 is the main body of the housing 10 and is typically cylindrical in shape. It is manufactured using a specific process to create a first mounting cavity with two openings. This mounting cavity provides mounting space for internal stator components such as the stator assembly 20. The housing 11 is typically made of a metal material with sufficient strength and good heat dissipation properties, such as aluminum alloy, which ensures the structural stability of the motor during operation and effectively dissipates the heat generated by the motor. The first end cover 12 and the second end cover 13 together seal the first mounting cavity. The first end cover 12 is fitted onto one opening of the first mounting cavity and is typically securely fixed to the housing 11 using screws or clips to prevent dust, foreign objects, etc., from entering the motor and affecting its normal operation. The second end cover 13 is fitted onto the other opening of the first mounting cavity and works in conjunction with the first end cover 12. A mounting groove 131 is provided on one surface facing the housing 11. This mounting groove 131 is mainly used to mount the mounting plate 41 of the Hall plate 40, providing a stable mounting position for the Hall plate 40. The stator assembly 20 is installed in the first mounting cavity and is one of the key components for the motor to convert electrical energy into magnetic energy. The second mounting cavity formed inside it provides space for the installation and rotation of the rotor assembly 30. When alternating current is applied, the stator assembly 20 generates a rotating magnetic field, thereby driving the rotor assembly 30 to rotate. The rotor assembly 30 is installed in the second mounting cavity and is the rotating part of the motor. One end of it extends out of the second mounting cavity and the first end cover 12. This end is usually connected to a load, such as fan blades or transmission gears, for outputting power. The other end extends out of the second mounting cavity and is rotatably connected to the second end cover 13. Meanwhile, suitable bearings and other rotatable connection structures are typically installed on the first end cover 12 and the second end cover 13 to ensure smooth rotation of the rotor assembly 30. Additionally, sealing rings are fitted around the outer periphery of the two bearings to reduce motor vibration and noise, prevent external impurities from entering the motor, and improve the motor's operational stability. The magnetic field generated by the rotor assembly 30 interacts with the rotating magnetic field generated by the stator assembly 20, propelling itself to rotate.

[0037] The Hall plate 40 includes a mounting plate 41 and a Hall element 42. The shape and size of the mounting plate 41 are adapted to the mounting groove 131 on the second end cover 13, allowing it to be tightly inserted into the inner circumference of the mounting groove 131, providing a stable mounting carrier for the Hall element 42. The mounting plate 41 is generally made of a material with good insulation properties, such as a plastic plate, to prevent short circuits or other faults between the Hall element 42 and components such as the housing 10. The insertion design of the mounting plate 41 and the mounting groove 131 greatly simplifies the assembly process. Operators only need to accurately insert the matching mounting plate 41 into the mounting groove 131 to complete the installation and fixation of the Hall plate 40 and the second end cover 13, without the need for other external fasteners such as bolts. This effectively reduces the overall size of the motor and the number of bolts and other fasteners, allowing for a more compact and rational use of the internal space of the motor. The Hall element 42 is mounted on the surface of the mounting plate 41 facing the housing 11. It is a magnetic sensor based on the Hall effect. When there is a change in the magnetic field, the Hall element 42 can generate an electrical signal related to the magnetic field strength. In the hollow cup brushless motor 100, the Hall element 42 is mainly used to detect information such as the position and speed of the rotor assembly 30, and transmit this information to the external control element in the form of electrical signals. The external control element controls the energizing sequence and current magnitude of the stator assembly 20 windings according to these signals, thereby achieving precise control of the motor speed, direction, etc.

[0038] like Figures 1 to 4 In one embodiment, the opening edge of the mounting groove 131 is bendable under external force, the thickness of the mounting plate 41 is less than the depth of the mounting groove 131, and the opening edge of the mounting groove 131 bends inward to form a limiting part, which abuts against the surface of the mounting plate 41 facing the housing 11.

[0039] In this embodiment, the edge of the mounting groove 131 is made of a metal material with a certain degree of flexibility and plasticity, such as aluminum alloy, to ensure that bending operations can be performed according to design requirements without damaging the material properties. The thickness of the mounting plate 41 is less than the depth of the mounting groove 131 to allow bending of the opening edge of the mounting groove 131. The limiting part is a structure formed by bending the opening edge of the mounting groove 131 inward. When the mounting plate 41 is inserted into the mounting groove 131, the limiting part can tightly abut against the surface of the mounting plate 41 facing the housing 11, preventing the mounting plate 41 from shaking or shifting within the mounting groove 131, thereby ensuring the installation stability of the Hall plate 40 and ensuring that the Hall element 42 can accurately detect relevant information of the rotor assembly 30. At the same time, the design of this limiting part simplifies the production and maintenance process. During the production process, after the assembly worker inserts the mounting plate 41 into the mounting slot 131, he only needs to perform a simple bending operation on the edge of the opening of the mounting slot 131 to fix the Hall plate 40, making the operation more convenient and efficient. In the maintenance stage, if the Hall plate 40 needs to be replaced, the operation can be reversed to restore the limiting part to its original state, and the mounting plate 41 can be easily removed for replacement, reducing the maintenance difficulty and cost.

[0040] like Figures 1 to 4 In one embodiment, the opening edge of the mounting groove 131 is provided with a plurality of limiting portions, which abut against the surface of the mounting plate 41 facing the housing 11.

[0041] In this embodiment, the opening edge of the mounting groove 131 is bent inward multiple times at intervals to form multiple limiting parts. These limiting parts are spaced a certain distance apart to ensure that each limiting part functions effectively and avoids mutual interference. Simultaneously, the space at the edge of the mounting groove 131 is utilized efficiently to prevent the edge strength of the mounting groove 131 from decreasing or affecting the installation of other components due to excessive or densely packed limiting parts. In this embodiment, the multiple limiting parts abutting against the mounting plate 41 at intervals greatly enhances the fixing effect on the mounting plate 41. During motor operation, multi-directional vibrations and impacts are generated. A single limiting part may not be able to completely resist these complex external forces, causing slight displacement of the mounting plate 41. However, the multiple spaced limiting parts can apply forces to the mounting plate 41 from different directions, effectively offsetting the influence of various external forces on the mounting plate 41, ensuring that the mounting plate 41 remains stable within the mounting groove 131. This, in turn, ensures that the Hall element 42 on the Hall plate 40 accurately detects the information of the rotor assembly 30, maintaining stable and efficient motor operation.

[0042] like Figures 1 to 4 In one embodiment, the outer periphery of the opening edge of the mounting groove 131 is provided with a rounded chamfer 132, which is arranged in a ring shape.

[0043] In this embodiment, the rounded chamfer 132 is machined from any point on the edge of the opening of the mounting groove 131 and surrounds the edge of the opening of the mounting groove 131, so that the entire edge of the opening is machined into this rounded chamfer 132 structure with the same characteristics. The design of the rounded chamfer 132 serves as a guide, guiding the mounting plate 41 to slide smoothly into the mounting groove 131, reducing resistance and deviation during the installation process, and greatly improving assembly efficiency. On the other hand, the design of the rounded chamfer 132 greatly facilitates the subsequent bending operation. The rounded surface of the rounded chamfer 132 can provide the operator with a more stable point of force, and can more accurately control the bending angle and force, thereby reducing the defect rate caused by operational errors and improving the overall production quality.

[0044] like Figures 1 to 4 In one embodiment, the installation gap between the mounting plate 41 and the inner wall of the mounting groove 131 is i, where 0.01mm≤i≤0.03mm.

[0045] In this embodiment, there is a certain installation gap between the mounting plate 41 and the inner wall of the mounting groove 131. On the one hand, if the installation gap is too small, the mounting plate 41 may experience significant resistance due to interference fit when inserted into the mounting groove 131, leading to installation difficulties or even damage to the mounting plate 41 or the mounting groove 131. On the other hand, if the gap is too large, the mounting plate 41 will wobble within the mounting groove 131, failing to guarantee its installation stability and thus affecting the accurate detection of rotor assembly 30 information by the Hall element 42. Therefore, in this embodiment, the range of the installation gap i is 0.01mm ≤ i ≤ 0.03mm, for example, 0.01mm, 0.02mm, or 0.03mm, to ensure that the mounting plate 41 can be smoothly installed into the mounting groove 131 while maintaining sufficient tightness to limit the wobbling amplitude of the mounting plate 41 within the groove and maintain its stability during motor operation.

[0046] like Figures 1 to 4 In one embodiment, the bottom wall of the mounting groove 131 is provided with a receiving groove 133. The receiving groove 133 and the mounting groove 131 are concentrically arranged. The other end of the rotor assembly 30 passes through the mounting plate 41 and is rotatably connected to the receiving groove 133. The surface of the mounting plate 41 facing away from the housing 11 abuts against the groove end face of the receiving groove 133.

[0047] In this embodiment, the receiving groove 133 is a hollow cylindrical structure with a bearing inside. The other end of the rotor assembly 30 is rotatably connected to the bearing in the receiving groove 133, ensuring that the rotor assembly 30 can rotate smoothly relative to the second end cover 13. Simultaneously, the concentric arrangement of the receiving groove 133 and the mounting groove 131 effectively reduces the radial runout of the rotor assembly 30, lowering vibration and noise caused by rotor instability, resulting in smoother motor operation. Furthermore, the groove end face of the receiving groove 133 provides additional support and positioning for the mounting plate 41, preventing displacement or wobbling during motor operation and ensuring that the Hall element 42 can accurately detect relevant information of the rotor assembly 30. At the same time, the contact between the mounting plate 41 and the groove end face of the receiving groove 133 further enhances the connection stability between the mounting plate 41 and the second end cover 13, making the entire internal structure of the motor more compact and stable.

[0048] like Figures 1 to 4 In one embodiment, the second end cap 13 further includes an abutment platform 134, which is arranged around the inner wall of the mounting groove 131, and the surface edge of the mounting plate 41 facing away from the housing 11 abuts against the abutment platform 134.

[0049] In this embodiment, the abutment platform 134 is an annular structure with a certain radial width and axial height. The abutment platform 134 is integrally formed with the other structures of the second end cover 13 to ensure the installation stability of the abutment platform 134. The design of the abutment platform 134 provides additional positioning and support for the mounting plate 41 in the mounting groove 131. Through the joint action with the groove end face of the receiving groove 133 in the above embodiment, the installation stability of the Hall plate 40 is further improved.

[0050] like Figures 1 to 5 In one embodiment, the rotor assembly 30 includes a rotating shaft 31, an annular magnet 32, a balance ring 33, a positioning element 34, and a tracking magnet. The annular magnet 32 ​​is installed in the second mounting cavity, and the rotating shaft 31 is installed on the annular magnet 32. One end of the rotating shaft 31 extends out of the first end cover 12, and the other end extends out of the second mounting cavity and is rotatably connected to the second end cover 13. The balance ring 33 is sleeved on the rotating shaft 31 and abuts against the end face of the annular magnet 32 ​​facing the first end cover 12.

[0051] The positioning element 34 is sleeved on the rotating shaft 31 and abuts against the end face of the annular magnet 32 ​​facing the second end cover 13. The positioning element 34 has a positioning groove, and the tracking magnet is located in the positioning groove.

[0052] In this embodiment, the rotor assembly 30 includes a shaft 31, an annular magnet 32, a balance ring 33, a positioning element 34, and a tracking magnet. The shaft 31 is the core rotating component of the rotor assembly 30, running through the entire assembly and serving to transmit torque and support other components. The shaft 31 is typically made of high-strength, high-toughness metal materials, such as alloy steel, to ensure it can withstand enormous torque and centrifugal force during high-speed motor operation. One end extends out of the first end cover 12 to connect to an external load and output the power generated by the motor; the other end extends out of the second mounting cavity and is rotatably connected to the second end cover 13. Through suitable bearings and other rotating connection devices, the shaft 31 can rotate smoothly, providing a stable rotational foundation for the motor's operation. The annular magnet 32 ​​is installed inside the second mounting cavity and is a key component for generating the magnetic field. It surrounds the shaft 31, and its magnetic field interacts with the rotating magnetic field generated by the stator assembly 20, driving the rotor assembly 30 to rotate. The annular magnet 32 ​​is generally made of high-performance permanent magnet materials, such as neodymium iron boron, which has characteristics such as high remanence and high coercivity, and can generate a strong and stable magnetic field, thereby ensuring that the motor has high efficiency and performance. The balance ring 33 is sleeved on the rotating shaft 31 and tightly abuts against the end face of the annular magnet 32 ​​facing the first end cover 12. Its main function is to balance the centrifugal force generated by the rotor assembly 30 due to manufacturing errors, component asymmetry, etc. when the motor rotates at high speed through its own mass distribution, thereby reducing the vibration and noise of the motor during operation and improving the stability and reliability of motor operation.

[0053] The positioning element 34 is also sleeved on the rotating shaft 31, and it abuts against the end face of the annular magnet 32 ​​facing the second end cover 13. The main function of the positioning element 34 is to provide an accurate installation position for the tracking magnet. By installing the tracking magnet in the positioning groove of the positioning element 34, the tracking magnet can be directly installed on the end of the annular magnet 32, which effectively shortens the axial dimension of the motor, makes the overall structure of the motor more compact, and improves the structural stability of the motor.

[0054] like Figures 1 to 5 In one embodiment, the annular magnet 32 ​​is a two-pair magnetized magnet.

[0055] In this embodiment, the annular magnet 32 ​​is magnetized in a specific pattern along its circumference to form two N poles and two S poles. Specifically, when viewed from one end of the annular magnet 32, the magnetic poles on its circumferential surface are found to be arranged in an alternating pattern, i.e., N pole, S pole, N pole, S pole are distributed in sequence. This makes the magnetic field distribution in the air gap of the motor more uniform, which is equivalent to uniformly distributing the magnetic field strength of a pair of poles. This prevents the magnetic field in the yoke (slotless iron core) from becoming too concentrated, effectively reducing eddy current losses in the motor. Furthermore, the dispersed magnetic field distribution enables the motor to provide a more stable output torque.

[0056] like Figures 1 to 5 In one embodiment, the tracking magnet includes four magnet bodies 35, which are connected end to end in a positioning groove.

[0057] In this embodiment, the tracking magnet is divided into four smaller magnet bodies 35, which significantly reduces the size of each magnet body 35 and makes the internal stress distribution of the material more uniform. During processing operations such as cutting and grinding, the force applied by the tool to the material is more easily and evenly distributed, greatly reducing the probability of defects caused by uneven stress on the material, thereby reducing the processing difficulty.

[0058] 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 hollow cup brushless motor, characterized by, The hollow cup brushless motor includes: The housing includes a shell, a first end cover, and a second end cover. The shell forms a first mounting cavity with two openings. The first end cover and the second end cover are respectively fitted onto the two openings of the first mounting cavity. The second end cover has a mounting groove on one surface facing the shell. A stator assembly, wherein the stator assembly is mounted in the first mounting cavity, and a second mounting cavity is formed within the stator assembly; A rotor assembly, wherein the rotor assembly is mounted in the second mounting cavity, one end of the rotor assembly extends out of the second mounting cavity and the first end cover, and the other end of the rotor assembly extends out of the second mounting cavity and is rotatably connected to the second end cover; and A Hall plate, comprising a mounting plate and a Hall element, wherein the mounting plate is inserted into the inner circumferential side of the mounting groove, and the Hall element is mounted on the surface of the mounting plate facing the housing and is used for electrical connection with an external control element.

2. The hollow cup brushless motor of claim 1, wherein, The opening edge of the mounting groove is designed to be bend under external force. The thickness of the mounting plate is less than the depth of the mounting groove. The opening edge of the mounting groove bends inward to form a limiting part, which abuts against the surface of the mounting plate facing the housing.

3. The hollow cup brushless motor of claim 2, wherein, The opening edge of the mounting groove is provided with a plurality of limiting portions, each of which abuts against the surface of the mounting plate facing the housing.

4. The hollow cup brushless motor of claim 2, wherein, The outer periphery of the opening edge of the mounting groove is provided with a rounded chamfer, which is arranged in a ring shape.

5. The hollow cup brushless motor of claim 2, wherein, The installation gap between the mounting plate and the side wall of the mounting groove is i, where 0.01mm≤i≤0.03mm.

6. The hollow cup brushless motor of claim 2, wherein, The bottom wall of the mounting groove is provided with a receiving groove, and the receiving groove and the mounting groove are concentrically arranged. The other end of the rotor assembly passes through the mounting plate and is rotatably connected to the bearing in the receiving groove. The surface of the mounting plate facing away from the housing abuts against the groove end face of the receiving groove.

7. The hollow cup brushless motor of claim 2, wherein, The second end cap further includes an abutment platform, which is arranged around the inner wall of the mounting groove, and the mounting plate abuts against the abutment platform on the surface edge opposite to the housing.

8. A hollow cup brushless motor according to any one of claims 1-7, characterized in that, The rotor assembly includes a rotating shaft, an annular magnet, a balance ring, a positioning component, and a tracking magnet. The annular magnet is installed in the second mounting cavity. The rotating shaft passes through the annular magnet. One end of the rotating shaft extends out of the first end cover, and the other end extends out of the second mounting cavity and is rotatably connected to the second end cover. The balance ring is sleeved on the rotating shaft and abuts against the end face of the annular magnet facing the first end cover. The positioning element is sleeved on the rotating shaft and abuts against the end face of the annular magnet facing the second end cover. The positioning element has a positioning groove, and the tracking magnet is disposed in the positioning groove.

9. The hollow cup brushless motor of claim 8, wherein, The ring magnet is a two-pair magnetized magnet.

10. The hollow cup brushless motor of claim 8, wherein, The tracking magnet includes four magnet bodies, which are connected end-to-end in the positioning groove.

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