Convenient installation of strong magnetic brushless motor outer rotor

Abstract

The utility model discloses a kind of brushless motor outer rotor of strong magnet for facilitating installation, including machine shell, it is characterized by: in the upper and lower direction interval symmetry of the machine shell inner wall is provided with upper locating ring and lower locating ring, several upper locating convex strips are uniformly distributed on the upper locating ring along the circumferential direction, upper magnetic sheet clamping groove is enclosed between two adjacent upper locating convex strips, lower locating convex strip is arranged in the corresponding position of the lower locating ring and upper locating convex strip, lower magnetic sheet clamping groove is enclosed between two adjacent lower locating convex strips, and magnetic sheet is installed in the upper magnetic sheet clamping groove and lower magnetic sheet clamping groove.The utility model aims at overcoming the deficiencies in the prior art, provide a kind of brushless motor outer rotor with simple structure, can realize magnetic sheet fast, accurate, firm installation, and can adapt to different specifications magnetic sheet, simplify assembly process, improve production efficiency and motor operation reliability.

Description

Technical Field

[0001] This utility model relates to the field of brushless motor technology, specifically to an external rotor for a brushless motor that is easy to install with a strong magnet. Background Technology

[0002] Brushless motors are widely used in numerous fields such as industrial drives, new energy vehicles, aerospace, home appliances, and medical devices due to their high efficiency, high reliability, low maintenance costs, and excellent speed regulation performance. External rotor brushless motors, as an important structural form of brushless motors, are characterized by their rotor housing being directly connected to the load. They offer advantages such as large rotational inertia and good heat dissipation, making them particularly common in scenarios requiring direct drive or high torque output.

[0003] One of the core components of an external rotor brushless motor is the permanent magnet (commonly called a magnet or magnetic sheet) mounted on the inner wall of the external rotor. Its performance, installation precision, and firmness directly affect the motor's electromagnetic performance, operational smoothness, efficiency, and reliability. Currently, the main methods for fixing the magnetic sheets on the inner wall of the external rotor include adhesive bonding. Adhesive bonding is one of the most traditional and common methods, as it is relatively simple and cost-effective.

[0004] Traditional adhesive bonding methods typically involve machining steps or adhesive grooves on the inner wall of the rotor housing to position the magnetic sheets, then applying adhesive to the surface of the magnetic sheets or the inner wall of the housing, and finally attaching the magnetic sheets one by one to their predetermined positions. However, this method has the following significant drawbacks: 1. Difficult and inefficient installation and positioning: Magnetic sheets typically have strong magnetic force, which easily attracts or repels each other during installation, making precise alignment difficult, inconvenient to operate, and prone to misalignment, tilting, or even hand injury to operators or damage to the magnetic sheets. The installation process is highly dependent on the experience and skills of the operators, with low automation, severely impacting assembly efficiency.

[0005] 2. Poor positioning accuracy and consistency: The adhesive is fluid before curing. The magnetic sheet may slip after being pasted but before the adhesive cures, making it difficult to guarantee the positional accuracy and consistency of the magnetic sheet in the circumferential and radial directions. This results in uneven air gap in the motor, causing electromagnetic force fluctuations, increased noise, and aggravated vibration, and may even affect the output torque and efficiency of the motor.

[0006] 3. Reliability Risks: During motor operation, especially at high speeds, the magnetic sheets are subjected to tremendous centrifugal force, vibration, and impact. Over time, the adhesive may weaken due to aging, high temperatures, humidity changes, and other factors, leading to a risk of loosening or even detachment of the magnetic sheets. This not only affects motor performance but could also cause serious safety accidents.

[0007] The process conditions are demanding: the quality of the adhesive is affected by many factors such as the type of adhesive, the amount of adhesive applied, the uniformity of the adhesive application, the curing temperature, the curing time, and the cleanliness of the bonding surface. The process control is difficult and bonding defects are prone to occur.

[0008] 4. Inconvenient maintenance and replacement: Once the magnetic sheet is damaged or needs to be replaced, it is extremely difficult to disassemble the magnetic sheet which is fixed with adhesive. It often requires violent disassembly, which may damage the outer rotor housing and is not conducive to later maintenance and recycling.

[0009] Therefore, the existing external rotor of brushless motors needs further improvement. Utility Model Content

[0010] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a brushless motor external rotor that has a simple structure, enables fast, accurate and secure installation of magnetic sheets, can adapt to magnetic sheets of different specifications, simplifies the assembly process, and improves production efficiency and motor operation reliability.

[0011] To achieve the above objectives, the present invention adopts the following solution: an external rotor for a brushless motor that facilitates the installation of a strong magnet, comprising a housing, characterized in that: an upper positioning ring and a lower positioning ring are symmetrically arranged at intervals along the upper and lower directions on the inner wall of the housing; a plurality of upper positioning protrusions are evenly distributed along the circumferential direction on the upper positioning ring; an upper magnetic sheet engaging groove is formed between two adjacent upper positioning protrusions; a lower positioning protrusion is provided at a position corresponding to the upper positioning protrusion on the lower positioning ring; a lower magnetic sheet engaging groove is formed between two adjacent lower positioning protrusions; and a magnetic sheet is installed in the upper magnetic sheet engaging groove and the lower magnetic sheet engaging groove.

[0012] As another improvement of the present invention for facilitating the installation of a strong magnet on the outer rotor of a brushless motor, an upper guide chamfer is provided on the upper positioning protrusions on both sides of the entrance of the upper magnetic plate slot, and a lower guide chamfer is provided on the lower positioning protrusions on both sides of the entrance of the lower magnetic plate slot.

[0013] As another improvement of this utility model for facilitating the installation of the outer rotor of a brushless motor with a strong magnet, a number of upper locking protrusions are evenly distributed along the circumferential direction on the outer wall of the upper positioning ring, and an upper positioning locking groove is provided on the inner wall of the housing at the corresponding position of the upper locking protrusions, and the upper locking protrusions are inserted into the upper positioning locking grooves.

[0014] As another improvement of this utility model for facilitating the installation of the outer rotor of a brushless motor with a strong magnet, a lower locking protrusion is provided on the outer wall of the lower positioning ring at a position corresponding to the upper locking protrusion, and a lower positioning locking groove is provided on the inner wall of the housing at a position corresponding to the lower locking protrusion, with the lower locking protrusion inserted into the lower positioning locking groove.

[0015] As another improvement of this utility model for facilitating the installation of a strong magnet external rotor of a brushless motor, the housing includes a lower cover, a middle cover, and an upper cover connected in sequence.

[0016] As another improvement of this utility model for facilitating the installation of a strong magnet brushless motor outer rotor, a lower connecting part is provided on the outer periphery of the lower cover, and a lower limiting inner boss is provided on the lower connecting part. The lower end of the middle cover abuts against the lower connecting part, and the lower end of the inner side of the middle cover abuts against the outer wall of the lower limiting inner boss. The lower end face of the lower positioning ring is provided on the limiting inner boss. An upper connecting part is provided on the outer periphery of the upper cover, and an upper limiting inner boss is provided on the upper connecting part. The upper end of the middle cover abuts against the upper connecting part, and the lower end of the inner side of the middle cover abuts against the outer wall of the upper limiting inner boss. The lower end face of the upper limiting inner boss presses against the upper end face of the upper positioning ring.

[0017] As another improvement of this utility model for facilitating the installation of a strong magnet on the outer rotor of a brushless motor, several lower positioning grooves are evenly distributed on the upper circumference of the inner boss of the lower limit position. A lower positioning protrusion is provided at the corresponding position on the lower end face of the lower positioning ring and the lower positioning groove. The lower positioning protrusion is inserted into the lower positioning groove.

[0018] As another improvement of this utility model for facilitating the installation of the outer rotor of a brushless motor with a strong magnet, several upper positioning grooves are evenly distributed on the upper circumference of the upper upper positioning inner boss, and an upper positioning protrusion is provided at the corresponding position on the lower end face of the upper positioning ring and the upper positioning groove, and the upper positioning protrusion is inserted into the upper positioning groove.

[0019] In summary, the advantages of this utility model compared to the prior art are as follows: 1. This utility model has a simple structure. The separate setting of the upper and lower positioning rings allows for adjustment of the axial spacing according to the length of the magnetic sheet, making it suitable for magnetic sheets of different specifications, broadening the product's application range, and facilitating serialization development. 2. The magnetic sheet locking slot design makes the magnetic sheet easy to install, eliminating the need for complex tooling or positioning measurements. 3. The upper and lower positioning locking slots work together to ensure the consistency of the magnetic sheet's position in the circumferential and radial directions, thereby guaranteeing the electromagnetic performance and smooth operation of the motor. 4. The upper and lower positioning locking slots work together to provide mechanical constraints, resisting centrifugal force, vibration, and impact generated by high-speed rotation, preventing the magnetic sheet from falling off. 5. Through the dual rigid constraint mechanism of "lower support and upper clamping," the magnetic sheet assembly is firmly locked within the predetermined axial space. This effectively prevents axial movement or displacement of the rotor under any operating conditions (static, high-speed operation, acceleration, deceleration, or axial impact), ensuring absolute positional stability. Attached Figure Description

[0020] Figure 1 This is a three-dimensional schematic diagram of the present invention.

[0021] Figure 2 This is a schematic diagram of the internal structure of this utility model.

[0022] Figure 3 This is one of the schematic diagrams showing the assembled upper positioning ring, lower positioning ring, and magnetic sheet of this utility model.

[0023] Figure 4 for Figure 3 Enlarged diagram of point A in the middle.

[0024] Figure 5 This is the second schematic diagram of the assembled upper positioning ring, lower positioning ring, and magnetic sheet of this utility model.

[0025] Figure 6 for Figure 5 Enlarged diagram of point B in the middle.

[0026] Figure 7 This is a schematic diagram of the lower cover of this utility model.

[0027] Figure 8 for Figure 7 Enlarged diagram of point C in the middle.

[0028] Figure 9 This is a cross-sectional schematic diagram of the present invention.

[0029] Figure 10 for Figure 9 Enlarged diagram of point D in the middle. Detailed Implementation

[0030] The above-mentioned and other technical features and advantages of this utility model will be described in more detail below with reference to the accompanying drawings.

[0031] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0032] It should be noted that in the description of this utility model, the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0033] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of 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.

[0034] like Figure 1-10 As shown, a brushless motor outer rotor that facilitates the installation of strong magnets includes a housing 1. Upper positioning rings 2 and lower positioning rings 3 are symmetrically arranged at intervals along the upper and lower directions on the inner wall of the housing 1. Several upper positioning protrusions 4 are evenly distributed along the circumferential direction on the upper positioning rings 2. An upper magnetic sheet engaging groove 5 is formed between two adjacent upper positioning protrusions. Lower positioning protrusions 6 are arranged at corresponding positions on the lower positioning rings 3 and upper positioning protrusions 4. A lower magnetic sheet engaging groove 7 is formed between two adjacent lower positioning protrusions. Magnetic sheets 8 are installed in the upper magnetic sheet engaging groove 5 and the lower magnetic sheet engaging groove 7.

[0035] In this invention, the upper positioning ring 2 and the lower positioning ring 3 are set separately from each other, and the distance between them (axial interval) can be adjusted according to the length of the selected magnetic sheet, which greatly expands the applicability and versatility of the external rotor design, improves design flexibility, and is conducive to the development of serialized products.

[0036] In this invention, the upper magnetic plate retaining groove 5 and the lower magnetic plate retaining groove 7 provide excellent positioning for the magnetic plates during installation and separate adjacent magnetic plates, preventing them from adhering together. The magnetic plates simply slide into the corresponding grooves axially, eliminating the need for complex tooling fixtures or tedious positioning measurements. This effectively avoids the problems of magnetic plates easily sliding, shifting, or tilting in traditional adhesive bonding processes, significantly reducing reliance on operator experience and skills, and effectively improving assembly efficiency. The upper magnetic plate retaining groove 5 and the lower magnetic plate retaining groove 7 work together to ensure the positional accuracy and consistency of the magnetic plates in both the circumferential and radial directions, effectively ensuring the electromagnetic performance and smooth operation of the motor. The upper magnetic plate retaining groove 5 and the lower magnetic plate retaining groove 7 provide effective mechanical constraints on the magnetic plates, especially in the circumferential direction. This effectively resists centrifugal force, vibration, and impact generated by high-speed rotation, preventing magnetic plates from falling off and improving the reliability of motor operation.

[0037] Traditional magnet bonding relies entirely on the adhesive strength of the glue, and has extremely high requirements for the cleanliness of the bonding process, the amount of glue applied, and the curing conditions. In this solution, the slot structure undertakes the main positioning and mechanical fixing functions, and the requirements for the adhesive strength and process consistency can be relatively reduced.

[0038] In this invention, upper guide chamfers are provided on the upper positioning protrusions 4 on both sides of the entrance of the upper magnetic chip slot 5, and lower guide chamfers are provided on the lower positioning protrusions 6 on both sides of the entrance of the lower magnetic chip slot 7. The upper and lower guide chamfers in this invention can more smoothly guide the magnetic chip into the upper magnetic chip slot 5 and the lower magnetic chip slot 7, reducing frictional resistance during installation and damage to the edges of the magnetic chip, making installation by hand or with simple tools easier.

[0039] In this invention, a plurality of upper locking protrusions 9 are evenly distributed along the circumferential direction on the outer wall of the upper positioning ring 2, and an upper positioning locking groove 10 is provided on the inner wall of the housing 1 at a position corresponding to the upper locking protrusions 9, and the upper locking protrusions 9 are inserted into the upper positioning locking groove 10.

[0040] In the first embodiment of this utility model, the upper locking protrusion 9 of the upper positioning ring 2 cooperates with the upper positioning locking groove 10 to effectively prevent any circumferential slippage or rotational displacement of the upper positioning ring relative to the inner wall of the housing when the motor is running at high speed and the outer rotor is subjected to huge centrifugal force, thus ensuring the absolute fixation of the position of the upper positioning ring. Since a number of magnetic pieces 8 are evenly distributed between the upper positioning ring 2 and the lower positioning ring 3, the lower positioning ring 3 is constrained by the magnetic pieces 8 and the upper positioning ring 2. At the same time, the lower end of the lower positioning ring 3 presses against the bottom surface of the housing 1, thereby allowing it to be stably set on the inner wall of the housing 1.

[0041] In this utility model, a lower locking protrusion 11 is provided on the outer wall of the lower positioning ring 3 at a position corresponding to the upper locking protrusion 9, and a lower positioning locking groove 12 is provided on the inner wall of the housing 1 at a position corresponding to the lower locking protrusion 11, and the lower locking protrusion 11 is inserted into the lower positioning locking groove 12.

[0042] In the second embodiment of this utility model, based on the first embodiment, a lower locking protrusion 11 is also provided on the outer wall of the lower positioning ring 3, and a lower positioning locking groove 12 is machined at a corresponding position on the inner wall of the housing. The lower locking protrusion 11 is directly inserted into the lower positioning locking groove 12. The independent and direct mechanical positioning and locking between the lower positioning ring 3 and the housing 1 completely eliminates any possibility of circumferential or axial movement of the lower positioning ring relative to the inner wall of the housing. Both the upper and lower positioning rings are locked to the housing grooves by their own protrusions, realizing the double locking of the rotor core positioning components. This double protection greatly enhances the rigidity and integrity of the entire outer rotor structure under high-speed and high-torque conditions, effectively resisting complex rotational stresses and vibrations.

[0043] The housing 1 of this utility model includes a lower cover 13, a middle cover 14, and an upper cover 15 connected in sequence. A lower through hole 16 is provided on the upper cover 14, a middle through hole 17 is provided on the middle cover 14 at a corresponding position to the lower through hole 16, and an upper through hole 18 is provided on the upper cover 15 at a corresponding position to the middle through hole 17. Connecting bolts are provided in the lower through hole 16, the middle through hole 17, and the upper through hole 18.

[0044] In this utility model, a lower connecting part 19 is provided on the outer periphery of the lower cover 13, and a lower limiting inner boss 20 is provided on the lower connecting part 19. The lower end of the middle cover 14 abuts against the lower connecting part 19, and the lower end of the inner side of the middle cover 14 abuts against the outer wall of the lower limiting inner boss 20. The lower end face of the lower positioning ring 3 is provided on the limiting inner boss 20. An upper connecting part 21 is provided on the outer periphery of the upper cover 15, and an upper limiting inner boss 22 is provided on the upper connecting part 21. The upper end of the middle cover 14 abuts against the upper connecting part 21, and the lower end of the inner side of the middle cover 14 abuts against the outer wall of the upper limiting inner boss 22. The lower end face of the upper limiting inner boss 22 presses against the upper end face of the upper positioning ring 2.

[0045] In this invention, the lower end face of the lower positioning ring is directly set on the lower limit inner boss 20, precisely locking the absolute zero position of the lower positioning ring in the axial direction, becoming the basic reference point for the axial positioning of the entire rotor assembly. This completely eliminates the possibility of the lower positioning ring sinking axially. The lower end face of the limit inner boss is directly pressed against the upper end face of the upper positioning ring, precisely locking the final position of the upper positioning ring in the motor axial direction, and rigidly constraining the upward floating tendency of the entire rotor assembly containing the magnetic plate group in the axial direction. In this invention, through the dual rigid constraint mechanism of "lower support and upper pressing", the core component consisting of the upper positioning ring 2, the magnetic plate group 8, and the lower positioning ring 3 is effectively and firmly locked in the predetermined axial space. Regardless of whether the motor is static or running at high speed, accelerating, decelerating, or subjected to axial impact, the rotor can maintain the absolute position stability in the axial direction, preventing any axial movement or displacement.

[0046] In this utility model, a plurality of lower positioning grooves 23 are evenly distributed along the circumference of the lower limit inner boss 20, and a lower positioning protrusion 24 is provided at the corresponding position of the lower positioning groove 23 on the lower end face of the lower positioning ring 3, and the lower positioning protrusion 24 is inserted into the lower positioning groove 23.

[0047] In this invention, the lower positioning protrusion 24 and the lower positioning groove 23 cooperate with each other to effectively lock the lower positioning ring 3 and the lower cover 13 together. Even under the action of huge centrifugal force or alternating torque generated by high speed, this plug-in cooperation can effectively suppress any slight circumferential rotation or movement of the lower positioning ring relative to the lower limit inner boss, greatly enhancing circumferential stability.

[0048] In this invention, a plurality of upper positioning grooves 25 are evenly distributed along the circumference of the upper upper positioning inner boss 22. An upper positioning protrusion 26 is provided on the lower end face of the upper positioning ring 2 at a position corresponding to the upper positioning groove 25, and the upper positioning protrusion 26 is inserted into the upper positioning groove 25. In this invention, the upper positioning protrusion 26 and the upper positioning groove 25 cooperate to effectively lock the upper positioning ring 2 and the upper cover 15 together. Even under the action of huge centrifugal force or alternating torque generated by high rotation speed, this interlocking fit can effectively suppress any slight circumferential rotation or movement of the upper positioning ring relative to the upper upper positioning inner boss, greatly enhancing circumferential stability.

[0049] The foregoing has shown and described the basic principles and main features of this utility model, as well as its advantages. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A brushless motor outer rotor that facilitates the installation of a strong magnet, comprising a housing (1), characterized in that: An upper positioning ring (2) and a lower positioning ring (3) are symmetrically arranged at intervals along the upper and lower directions on the inner wall of the housing (1). Several upper positioning protrusions (4) are evenly distributed along the circumferential direction on the upper positioning ring (2). An upper magnetic plate receiving groove (5) is formed between two adjacent upper positioning protrusions. A lower positioning protrusion (6) is arranged at the corresponding position of the lower positioning ring (3) and the upper positioning protrusion (4). A lower magnetic plate receiving groove (7) is formed between two adjacent lower positioning protrusions. A magnetic plate (8) is installed in the upper magnetic plate receiving groove (5) and the lower magnetic plate receiving groove (7).

2. The external rotor of a brushless motor with a strong magnet that is easy to install according to claim 1, characterized in that: An upper guide chamfer is provided on the upper positioning protrusion (4) on both sides of the entrance of the upper magnetic card slot (5), and a lower guide chamfer is provided on the lower positioning protrusion (6) on both sides of the entrance of the lower magnetic card slot (7).

3. The external rotor of a brushless motor with a strong magnet that is easy to install according to claim 1, characterized in that: Several upper snap-fit ​​protrusions (9) are evenly distributed along the circumferential direction on the outer wall of the upper positioning ring (2). An upper positioning snap-fit ​​groove (10) is provided on the inner wall of the housing (1) at the corresponding position of the upper snap-fit ​​protrusions (9). The upper snap-fit ​​protrusions (9) are inserted into the upper positioning snap-fit ​​groove (10).

4. The external rotor of a brushless motor with a strong magnet that is easy to install according to claim 3, characterized in that: Lower locking protrusions (11) are respectively provided on the outer wall of the lower positioning ring (3) at the position corresponding to the upper locking protrusion (9), and lower positioning locking grooves (12) are provided on the inner wall of the housing (1) at the position corresponding to the lower locking protrusions (11). The lower locking protrusions (11) are inserted into the lower positioning locking grooves (12).

5. The external rotor of a brushless motor with a strong magnet that is easy to install according to claim 1, characterized in that: The housing (1) includes a lower cover (13), a middle cover (14) and an upper cover (15) connected in sequence.

6. The external rotor of a brushless motor with a strong magnet that is easy to install according to claim 5, characterized in that: A lower connecting part (19) is provided on the outer periphery of the lower cover (13), and a lower limiting inner boss (20) is provided on the lower connecting part (19). The lower end of the middle cover (14) abuts against the lower connecting part (19), and the lower end of the inner side of the middle cover (14) abuts against the outer wall of the lower limiting inner boss (20). The lower end face of the lower positioning ring (3) is provided on the limiting inner boss (20). An upper connecting part (21) is provided on the outer periphery of the upper cover (15), and an upper limiting inner boss (22) is provided on the upper connecting part (21). The upper end of the middle cover (14) abuts against the upper connecting part (21), and the lower end of the inner side of the middle cover (14) abuts against the outer wall of the upper limiting inner boss (22). The lower end face of the upper limiting inner boss (22) presses against the upper end face of the upper positioning ring (2).

7. The external rotor of a brushless motor with a strong magnet that is easy to install according to claim 6, characterized in that: Several lower positioning grooves (23) are evenly distributed along the circumference of the lower limit inner boss (20). A lower positioning protrusion (24) is provided at the corresponding position of the lower positioning groove (23) on the lower end face of the lower positioning ring (3). The lower positioning protrusion (24) is inserted into the lower positioning groove (23).

8. A brushless motor external rotor for easy installation of a strong magnet, as described in claim 6 or 7, characterized in that: Several upper positioning grooves (25) are evenly distributed along the circumference of the upper upper positioning inner boss (22). An upper positioning protrusion (26) is provided at the corresponding position of the upper positioning groove (25) on the lower end face of the upper positioning ring (2). The upper positioning protrusion (26) is inserted into the upper positioning groove (25).

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