Stator assembly and external rotor motor

Abstract

The utility model relates to the technical field of motors, and discloses a stator assembly and an external rotor motor. The stator assembly comprises a plurality of stator units and a plastic package body. The plurality of stator units are arranged around a preset direction, and each stator unit comprises a block iron core, an insulating skeleton sleeving the block iron core, and a coil winding arranged on the insulating skeleton. The plastic package body is arranged in a ring shape around a preset direction, accommodating spaces for accommodating the stator units are formed in the plastic package body, the accommodating spaces correspond to the stator units, and each stator unit is fixed in the corresponding accommodating space. According to the stator assembly and the external rotor motor provided by the invention, the manufacturing form of the stator assembly can be simplified.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a stator assembly and an external rotor motor. Background Technology

[0002] With the continuous development of power tool manufacturing technology, more and more construction sites are adopting power tools for processing. The use of power tools can effectively save manpower and improve work efficiency. At the same time, power tools can ensure processing accuracy by controlling their operating status. The motor is the driving part of the power tool, which drives the actuators to perform the corresponding processing operations.

[0003] The stator assembly is a crucial component of an electric motor. It generates a magnetic field that drives the rotor assembly to rotate. The design of the stator assembly significantly impacts the complexity of its manufacturing process. Therefore, designing the stator assembly structure to simplify its fabrication is an important issue. Utility Model Content

[0004] The purpose of this application is to provide a stator assembly and an external rotor motor, which can help simplify the manufacturing process of the stator assembly.

[0005] To address the aforementioned technical problems, embodiments of this application provide a stator assembly. The stator assembly includes multiple stator units and a molding compound. The multiple stator units are arranged around a predetermined direction. Each stator unit includes a segmented iron core, an insulating frame fitted onto the segmented iron core, and coil windings disposed on the insulating frame. The molding compound is arranged in a ring around the predetermined direction, forming a receiving space for accommodating the stator units. The receiving space corresponds to each stator unit, and each stator unit is fixed within its corresponding receiving space.

[0006] An embodiment of this application also provides an external rotor motor, which includes the stator assembly described above.

[0007] The stator assembly and external rotor motor provided in this application form a modular stator unit through the cooperation of segmented iron cores, insulating frames, and coil windings. Each stator unit is arranged around a predetermined direction to form the main body of the stator assembly. Simultaneously, the connection and fixation between the various stator units can be achieved through a molding compound. The molding compound can encapsulate different stator units, thereby fixing them within their corresponding receiving spaces, ultimately forming an integrated structure. The cooperation between the modular stator units and the molding compound simplifies the manufacturing process of the stator assembly and improves production efficiency and slot fill rate.

[0008] In some embodiments, the molding compound includes a first surface and a second surface disposed opposite to each other along a predetermined direction. The molding compound is provided with a first bearing mounting hole extending from the first surface toward the second surface and a second bearing mounting hole extending from the second surface toward the first surface. In this way, by integrating the bearing mounting holes on the molding compound, the number of components can be reduced and the structural form simplified.

[0009] In some embodiments, the diameter of the first bearing mounting hole is smaller than the diameter of the second bearing mounting hole. This allows for efficient use of space at different locations within the encapsulation by forming bearing mounting holes of varying diameters.

[0010] In some embodiments, there is a gap between the insulating frames of two adjacent stator units. This allows for the filling of the encapsulating material during the formation of the encapsulation body by providing a gap between the insulating frames.

[0011] In some embodiments, the insulating frame is provided with perforations, through which the segmented iron cores pass, allowing the insulating frame to be fitted onto the segmented iron cores. This allows for a modular connection between the segmented iron cores and the insulating frame, simplifying the manufacturing process of the stator unit and improving slot fill factor.

[0012] In some embodiments, the insulating frame includes a connected main body and a first extension, the main body having perforations, and the first extension extending from the surface of the main body in a predetermined direction. This allows the first extension to enhance the locking effect of the encapsulation on the stator unit.

[0013] In some embodiments, the insulating frame further includes a second extension located on a different side of the main body and extending in opposite directions to the first extension. This second extension enhances the locking effect of the encapsulation on the stator unit.

[0014] In some embodiments, the main body, the first extension, and the second extension are integrally formed. This integral forming method ensures the overall structural strength of the insulating frame.

[0015] In some implementations, the surface of the encapsulated body away from the central axis is flush with the surfaces of the multiple stator units away from the central axis. This allows for the determination of the surface position of the encapsulated body, saving on the amount of encapsulating material used. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a schematic diagram of the main structure of a stator assembly provided in some embodiments of this application;

[0018] Figure 2 This is a cross-sectional structural schematic diagram of a stator assembly provided in some embodiments of this application;

[0019] Figure 3 This is a three-dimensional structural diagram of the stator unit in the stator assembly provided in some embodiments of this application when they are engaged;

[0020] Figure 4 This is a top view of the stator unit assembly provided in some embodiments of this application when the stator units are engaged.

[0021] Figure 5 This is a three-dimensional structural schematic diagram of a stator unit in a stator assembly provided in some embodiments of this application;

[0022] Figure 6 This is a three-dimensional structural diagram of the segmented iron core in the stator assembly provided in some embodiments of this application;

[0023] Figure 7 This is a three-dimensional structural schematic diagram of the insulating frame in the stator assembly provided in some embodiments of this application;

[0024] Figure 8 This is a schematic diagram of the mating structure between the insulating frame and the coil winding in a stator assembly provided in some embodiments of this application;

[0025] Figure 9 This is a three-dimensional structural schematic diagram of an external rotor motor provided in some embodiments of this application;

[0026] Figure 10 This is a schematic diagram of the front view structure of an external rotor motor provided in some embodiments of this application;

[0027] Figure 11 This is a cross-sectional structural schematic diagram of an external rotor motor provided in some embodiments of this application;

[0028] Figure 12 This is a bottom view schematic diagram of the external rotor motor provided in some embodiments of this application;

[0029] Figure 13 This is an exploded structural diagram of an external rotor motor provided in some embodiments of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0032] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0033] External rotor motors and internal rotor motors are two common types of motors. Unlike internal rotor motors, external rotor motors have the coils on the inside and the magnets on the outside, making them a type of motor that rotates on the outside. Compared to internal rotor motors, external rotor motors have a larger moment of inertia on their rotating shaft, making maintenance easier and offering advantages in coil winding operations. Therefore, external rotor motors are widely used in various power tools as a power source to drive the movement of actuators.

[0034] The stator assembly is a crucial component of an electric motor. When energized, the stator windings generate a magnetic field, which in turn excites the rotor assembly to rotate. The stator assembly comprises the stator core, insulating frame, and coil windings. Currently, the stator core in external rotor motors is primarily available in integrated and separate forms. When using an integrated stator core, the inner ring of the stator assembly is interference-fitted with the aluminum support. Due to the lack of specific positioning, it is prone to misalignment or warping during production. Furthermore, the integrated circular structure of the stator core means that after winding one slot, the stator core rotates to begin winding the next slot. Defects during production can cause all previous processes to fail, resulting in significant scrap costs. Conversely, when using a segmented stator core, the joints require laser welding or argon arc welding, a complex process.

[0035] To simplify the manufacturing process of stator assemblies, some embodiments of this application provide a stator assembly. The stator core is cut into sections on a mold according to its teeth; this sectional manufacturing method significantly increases material utilization. After the sectioned core is completed, it can be pushed into a wound insulating frame to form stator units. All stator units are then arranged circumferentially and placed into a mold for injection molding, forming a plastic seal on the surface of the stator units. This plastic seal can fix the different stator units, thereby avoiding complex welding processes and simplifying the manufacturing process of the stator assembly.

[0036] Meanwhile, the stator unit is highly modular, which can improve slot fill factor. This, in turn, improves production efficiency and the torque of the external rotor motor.

[0037] The following is combined with Figures 1 to 8 This application describes the structure of a stator assembly provided in some embodiments.

[0038] like Figures 1 to 8 As shown, some embodiments of this application provide a stator assembly including a plurality of stator units 11 and a molding compound 21. The plurality of stator units 11 are arranged around a predetermined direction ( Figures 1 to 3 As indicated by the arrow X, each stator unit 11 includes a segmented iron core 101, an insulating frame 102 fitted onto the segmented iron core 101, and a coil winding 103 disposed on the insulating frame 102. A molding compound 21 is arranged in a ring shape around a predetermined direction, forming a receiving space for accommodating the stator unit 11. The receiving space corresponds to the stator unit 11, and each stator unit 11 is fixed within its corresponding receiving space.

[0039] The stator unit 11 is highly modular, formed by pushing segmented iron cores 101 into the wound insulating frame 102. The segmented iron cores 101 are formed by dividing the integral stator core into sections. When multiple stator units 11 are arranged together, the closer sections form the yoke of the stator core, while the spaced sections form the teeth. The insulating frame 102 corresponds to the segmented iron cores 101, enabling high slot fill factor when individually wound to form the coil winding 103. Multiple stator units 11 are arranged around a predetermined direction, forming the base of the stator assembly. The predetermined direction coincides with or is parallel to the central axis of the external rotor motor. When two adjacent stator units 11 are arranged in a circle around the predetermined direction, they can maintain a certain interval or be positioned in a specific manner.

[0040] The encapsulation body 21 is formed on the surface of multiple stator units 11 by injection molding. Each stator unit 11 is fixed within the receiving space formed by the encapsulation body 21, thereby forming an integrated structure. The encapsulation body 21 can provide good sealing performance and prevent corrosion from the external environment.

[0041] The stator assembly provided in some embodiments of this application forms a modular stator unit 11 through the cooperation of a segmented iron core 101, an insulating frame 102, and a coil winding 103. Each stator unit 11 is arranged around a predetermined direction to form the main body 1021 of the stator assembly. Meanwhile, the connection and fixation between the various stator units 11 can be achieved through a molding compound 21. The molding compound 21 can encapsulate different stator units 11, thereby fixing them within their corresponding receiving spaces, ultimately forming an integrated structure. The cooperation between the modular stator units 11 and the molding compound 21 simplifies the manufacturing process of the stator assembly and improves production efficiency and slot fill rate.

[0042] In some embodiments, the molding compound 21 may include a first surface 201 and a second surface 202 disposed opposite to each other along a preset direction. The molding compound 21 is provided with a first bearing mounting hole 211 extending from the first surface 201 toward the second surface 202, and a second bearing mounting hole 212 extending from the second surface 202 toward the first surface 201.

[0043] The encapsulation body 21 not only wraps around the stator unit 11 to fix its position, but also serves as a stator support. In other words, when the encapsulation body 21 is formed by injection molding, the stator support portion is also formed simultaneously, providing an installation position for the bearing. This enables a rotational connection between the motor shaft and the stator assembly.

[0044] The first surface 201 and the second surface 202 are the two end faces of the encapsulated body 21. Bearing mounting holes are formed on the two end faces for mounting the first bearing and the second bearing that mate with the motor shaft. This simplifies the structure of the stator assembly and reduces the number of parts, effectively reducing the manufacturing cost of the external rotor motor.

[0045] In addition, the diameter of the first bearing mounting hole 211 can be smaller than the diameter of the second bearing mounting hole 212.

[0046] like Figure 2 As shown, the two bearing mounting holes are coaxially arranged on both sides of the encapsulation body 21, for Figure 9 The bearing installation at different positions on the motor shaft 31 shown provides advantageous space. By setting bearing mounting holes of different diameters at different positions, the space at these positions can be effectively utilized to reduce space occupation. This achieves the goal of reducing the size of the external rotor motor.

[0047] In some embodiments, there may be a gap between the insulating frames 102 of two adjacent stator units 11.

[0048] When multiple stator units 11 are arranged in a circle around a preset direction, the insulating frame 102 of two adjacent stator units 11 maintains a certain interval, which provides space for the filling of the encapsulation material. This ensures the effective fixation of the encapsulation material to different stator units 11.

[0049] like Figure 2 As shown, the insulating frame 102 may be provided with perforations 104, through which the segmented iron core 101 passes, so that the insulating frame 102 is fitted onto the segmented iron core 101.

[0050] In other words, the insulating frame 102 and the segmented iron core 101 are connected in a detachable manner. Figure 5 During the fabrication of the stator unit 11 shown, the stator core is designed and formed in sections. Figure 6 The segmented iron core 101 shown can be installed individually. Figure 7 The insulating frame 102 shown is formed by winding. Figure 8 The coil winding 103 shown is then... Figure 6 The segmented iron core 101 shown is pushed into the insulating frame 102 to form the stator unit 11. This not only simplifies the manufacturing process of the stator unit 11 but also improves the slot fill factor during winding, thereby enhancing the performance of the external rotor motor.

[0051] In some embodiments, the insulating frame 102 may include a connected main body 1021 and a first extension 1022, the main body 1021 being provided with a perforation 104, and the first extension 1022 extending from the surface of the main body 1021 along a predetermined direction.

[0052] The main body 1021 is the part that is fitted onto the segmented iron core 101, and the first extension 1022 is the part that extends outward. The first extension 1022 can increase the contact area with the molding compound 21, thereby ensuring the molding compound 21's wrapping effect on the stator unit 11, and ensuring the fixation effect of the stator unit 11 within the receiving space.

[0053] like Figure 3 and Figure 4 As shown, the first extensions 1022 of the insulating frame 102 of the plurality of stator units 11 form a ring and protrude from one side of the insulating frame 102. During injection molding to form the encapsulation body 21, the encapsulation material can fill both sides of the first extensions 1022 along a predetermined direction and completely cover the surface of the first extensions 1022. This ensures a locking effect between the stator units 11 and the encapsulation body 21.

[0054] In addition, the insulating frame 102 may also include a second extension 1023, which is located on a different side of the main body 1021 from the first extension 1022, and the second extension 1023 extends in opposite directions to the first extension 1022.

[0055] The second extension 1023 is located on the side of the main body 1021 away from the first extension 1022. The second extension 1023 can also increase the contact area with the encapsulation body 21, thereby ensuring the encapsulation body 21's wrapping effect on the stator unit 11 and ensuring the fixation effect of the stator unit 11 within the accommodating space.

[0056] During injection molding of multiple stator units 11, the second extensions 1023 of the insulating frame 102 of the multiple stator units 11 form a ring and protrude from one side of the insulating frame 102. When the encapsulated body 21 is formed by injection molding, the encapsulating material can fill both sides of the second extension 1023 along a predetermined direction and completely cover the surface of the second extension 1023. This ensures a locking effect between the stator units 11 and the encapsulated body 21.

[0057] In practice, the main body 1021, the first extension 1022, and the second extension 1023 can be integrally formed.

[0058] In other words, the insulating frame 102 is manufactured in a single piece, which ensures the overall structural strength and manufacturing precision of the insulating frame 102.

[0059] In some embodiments, the surface of the molding compound 21 away from the central axis can be flush with the surface of the plurality of stator units 11 away from the central axis, that is, the outer peripheral surface of the molding compound 21 is flush with the outer peripheral surface of the plurality of stator units 11.

[0060] The central axis is the centerline around which the encapsulated body 21 is located, and the surface of the encapsulated body 21 away from the central axis is its outer surface. By aligning the outer surface of the encapsulated body 21 with the outer surfaces of the multiple stator units 11, a good fixing effect on the stator units 11 can be ensured while saving on the use of encapsulation material. This reduces the manufacturing cost of the stator assembly.

[0061] Some embodiments of this application also provide an external rotor motor, which includes the stator assembly described above.

[0062] like Figures 9 to 13 As shown, the stator assembly cooperates with the rotor assembly. The rotor assembly includes an outer rotor housing 41, a magnet base 51, and magnets 61. The outer rotor housing 41 is connected to the motor shaft 31, which is rotatably connected to the encapsulated body 21 via a first bearing 71 and a second bearing 81. The magnets 61 are positioned corresponding to the stator unit 11. When the coil windings 103 of the stator unit 11 are energized, the magnetic field generated is collected and concentrated in the segmented iron core 101, thereby enhancing and guiding it to the rotor assembly, thus driving the rotor assembly to rotate. A through hole 411 can be opened at the bottom of the outer rotor housing 41 to allow air circulation and heat dissipation.

[0063] External rotor motors can be used in various power tools, such as electric hammers, reciprocating electric saws, or edge trimmers. By employing a split structure in the stator assembly, external rotor motors can reduce motor costs. During stator assembly manufacturing, the stator core is cut into sections on a mold according to its teeth; this modular manufacturing significantly increases material utilization. After the sectioned cores are completed, they are pushed into the wound insulating frame 102 to form stator units 11. All stator units 11 are then arranged circumferentially and placed in a mold for injection molding, forming a plastic seal 21 on the surface of the stator units 11. This plastic seal 21 secures the different stator units 11. This eliminates the need for complex processes such as welding in stator assembly manufacturing, simplifying the process.

[0064] Those skilled in the art will understand that the above embodiments are specific implementations of this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this application.

Claims

1. A stator assembly, characterized in that, include: Multiple stator units are arranged around a preset direction. Each stator unit includes a segmented iron core, an insulating frame fitted on the segmented iron core, and a coil winding disposed on the insulating frame. A molding compound is arranged in a ring shape around the preset direction. The molding compound forms a receiving space for accommodating the stator unit. The receiving space corresponds to the stator unit, and each stator unit is fixed in the corresponding receiving space.

2. The stator assembly according to claim 1, characterized in that: The encapsulation body includes a first surface and a second surface disposed opposite to each other along the preset direction. The encapsulation body is provided with a first bearing mounting hole extending from the first surface toward the second surface and a second bearing mounting hole extending from the second surface toward the first surface.

3. The stator assembly according to claim 2, characterized in that: The diameter of the first bearing mounting hole is not greater than the diameter of the second bearing mounting hole.

4. The stator assembly according to claim 1, characterized in that: There is a gap between the insulating frames of two adjacent stator units.

5. The stator assembly according to claim 1, characterized in that: The insulating frame is provided with perforations, through which the segmented iron core passes, so that the insulating frame is fitted onto the segmented iron core.

6. The stator assembly according to claim 5, characterized in that: The insulating frame includes a connected main body and a first extension, the perforation is provided in the main body, and the first extension extends from the main body along the preset direction.

7. The stator assembly according to claim 6, characterized in that: The insulating frame further includes a second extension, which is located on a different side of the main body and extends in opposite directions to the first extension; the main body, the first extension, and the second extension are integrally formed.

8. The stator assembly according to claim 1, characterized in that: The outer peripheral surface of the molding compound is flush with the outer peripheral surfaces of the plurality of stator units.

9. A stator assembly, characterized in that, include: Multiple stator units are arranged around a preset direction. Each stator unit includes a segmented iron core, an insulating frame fitted on the segmented iron core, and a coil winding disposed on the insulating frame. A molding compound is arranged in a ring shape around the preset direction. The molding compound is integrally injection molded to multiple stator units to fix the multiple stator units together. The molding compound forms a receiving space to accommodate the stator units, and each stator unit is fixed in the corresponding receiving space.

10. An external rotor motor, characterized in that, Includes the stator assembly as described in any one of claims 1 to 9.

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