Stator core, stator assembly and external rotor motor

Abstract

The utility model relates to the technical field of motors, and discloses a stator core, a stator assembly and an external rotor motor. The stator iron core comprises a plurality of block iron cores which are arranged around a preset direction, each block iron core comprises a matching part and an extending part which are connected, the matching part of one of two adjacent block iron cores is provided with a bulge, and the matching part of the other block iron core is provided with a groove. And the bulge of one of two adjacent block iron cores is clamped into the groove of the other block iron core, so that the matching parts of the plurality of block iron cores are encircled together to form a circumferential surface which is in interference fit with the stator bracket, and the bulge is limited in the groove on a plane which is vertical to the preset direction. According to the stator core, the stator assembly and the external rotor motor provided by the invention, the connection effect of the stator core during assembly can be ensured.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the motor technical field, in particular to a stator core, a stator assembly and an outer rotor motor. BACKGROUND

[0002] With the continuous development of electric tools, the applicability of various electric tools in different scenes is also continuously improved. The electric tool converts electric energy into mechanical energy through a motor, and then drives an execution component to realize a corresponding processing operation. The stable work of the motor affects the working performance of the electric tool.

[0003] The stator assembly is an important component of the motor, and the relatively complex component in the stator assembly is the stator core. The manufacturing form of the stator core affects the cost of the stator assembly and the assembly effect of various components in the motor. How to design the structure of the stator core to ensure the connection effect during assembly is an important problem. UTILITY MODEL CONTENT

[0004] The embodiment of the present application aims to provide a stator core, a stator assembly and an outer rotor motor, which can help to ensure the connection effect during assembly of the stator core.

[0005] To solve the above technical problems, the embodiment of the present application provides a stator core. The stator core comprises a plurality of block cores arranged around a preset direction, each block core comprises a fitting part and an extension part connected with each other, the fitting part of one of the two adjacent block cores is provided with a protrusion, and the fitting part of the other is provided with a groove, the protrusion of one of the two adjacent block cores is clamped into the groove of the other, so that the fitting parts of the plurality of block cores are surrounded together to form a circumferential surface in interference fit with a stator support, and the groove limits the protrusion from the inside in a plane perpendicular to the preset direction.

[0006] The embodiment of the present application further provides a stator assembly. The stator assembly comprises the above-mentioned stator core, a plurality of insulation skeletons and a coil winding. The plurality of insulation skeletons correspond to the plurality of block cores one by one, and each insulation skeleton is sleeved on the corresponding block core. The coil winding corresponding to the extension part of the block core is arranged on each insulation skeleton.

[0007] The embodiment of the present application further provides an outer rotor motor, which comprises the above-mentioned stator assembly.

[0008] The stator core provided by the embodiments of the present application is formed by splicing and combining sub-core blocks. The matching portions of two adjacent sub-core blocks are matched by protrusions and grooves, so as to be surrounded together and form a circumferential surface which is in interference fit with the stator support. When the stator core is assembled, the interference fit can make the matching between the protrusions and the grooves more compact, thereby ensuring the connecting effect of each sub-core block when the stator core is assembled.

[0009] In some embodiments, the protrusions and the grooves are arranged on the side of the matching portions of the two adjacent sub-core blocks which are close to each other. In this way, the protrusions and the grooves can be arranged on the surface with a larger matching surface area, thereby ensuring that there is enough area for the arrangement of the protrusions and the grooves.

[0010] In some embodiments, the grooves extend along a preset direction, and at least one end of the grooves is arranged through in the preset direction. In this way, the length of the arrangement of the grooves can be ensured by making the grooves extend along the preset direction.

[0011] In some embodiments, the maximum width of the protrusions in the direction perpendicular to the preset direction is greater than the width of the grooves at the opening which is perpendicular to the preset direction. In this way, the limiting effect of the protrusions can be ensured by arranging a smaller width at the opening of the grooves.

[0012] In some embodiments, the width of the grooves in the direction perpendicular to the preset direction first increases and then decreases in the protruding direction of the protrusions. In this way, the limiting effect of the protrusions and the reduction of the matching gap can be ensured by making the width of the grooves first increase and then decrease.

[0013] In some embodiments, the matching portions of each sub-core block are respectively provided with grooves and protrusions. In this way, the force acting on each sub-core block during assembly of the stator core can be more uniform by arranging the grooves and the protrusions on the matching portions of each sub-core block respectively.

[0014] In some embodiments, the side surface of the matching portion of at least part of the sub-core blocks away from the extension portion is provided with a protruding portion which is used to match with a recess portion on the stator support. In this way, the positioning effect of the assembly of the stator core and the stator support can be ensured by arranging the protruding portion.

[0015] In some embodiments, the protruding portion is arranged in a strip shape, and the length direction of the protruding portion is parallel to the preset direction. In this way, the sufficient matching length between the protruding portion and the stator support can be ensured by making the length direction of the protruding portion parallel to the preset direction. BRIEF DESCRIPTION OF DRAWINGS

[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 three-dimensional structural schematic diagram of the stator core provided in some embodiments of this application;

[0018] Figure 2 This is a top view of the stator core provided in some embodiments of this application;

[0019] Figure 3 This is a three-dimensional structural diagram of a segmented core in a stator core provided in some embodiments of this application;

[0020] Figure 4 This is a schematic diagram of the mating structure of two adjacent segmented cores in a stator core provided in some embodiments of this application;

[0021] Figure 5 This is a top view of a stator assembly provided in some embodiments of this application;

[0022] Figure 6 This is a schematic diagram of the mating structure of the stator assembly and stator support provided in some embodiments of this application. Detailed Implementation

[0023] 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.

[0024] 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.

[0025] 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.

[0026] Electric motors are mainly classified into external rotor motors and internal rotor 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.

[0027] 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.

[0028] To ensure the connection strength of the stator core when using a segmented structure, some embodiments of this application provide a stator core. The stator core is segmented into sections on a mold according to its teeth, significantly increasing material utilization. Different segments of the core are fitted together using protrusions and grooves. The grooves can limit the protrusions, ensuring that adjacent segments cannot become loose on the mounting plane.

[0029] Single-piece segmented iron cores can be injection molded to form a skeleton or fitted with a plastic skeleton for winding. Due to the absence of lateral obstructions, a larger number of coils can be wound on a segmented iron core, achieving high slot fill factor, reducing copper losses, and minimizing heat generation. After winding, the segmented iron cores can be spliced ​​together to form a complete stator assembly.

[0030] The inner ring of the stator core and the outer ring of the stator support are fitted with an interference fit, allowing for installation via press-fitting or liquid nitrogen cold pressing. After installation, the stator core ensures a certain bonding force between each pair of core sections and between each core section and the stator support, thus guaranteeing the connection strength of the stator core during assembly.

[0031] The following is combined with Figures 1 to 4 This application describes the structure of the stator core provided in some embodiments.

[0032] like Figures 1 to 4 As shown, the stator core 11 provided in some embodiments of this application includes a plurality of segmented cores 111 arranged around a preset direction. Each segmented core 111 includes a connected mating portion 112 and an extension portion 113. The mating portion of each segmented core 111 is provided with a protrusion 101 and a groove 102. The protrusion 101 and the groove 102 are located on both sides of the circumference of each mating portion 112. The protrusion 101 of one of two adjacent segmented cores 111 is inserted into the groove 102 of the other, so that the mating portions 112 of the plurality of segmented cores 111 are connected end to end in a circumferential shape to form a circumferential surface that is interference-fitted with the stator support 41.

[0033] The stator core 11 is formed by circumferentially arranged segmented cores, which improves material utilization. The mating portions 112 of each segmented core 111 are arranged together to form the yoke of the stator core 11, and the extension portion 113 of each segmented core 111 forms the teeth of the stator core 11, which can be used to arrange the coil windings 31. The mating portions 112 of the segmented cores 111 can be spliced ​​together by the mating of protrusions 101 and grooves 102. Simultaneously, the grooves 102 can limit the protrusions 101 on a plane perpendicular to a predetermined direction. That is, the protrusions 101 and grooves 102 have varying widths. The protrusions 101 can be inserted into the grooves 102 along a predetermined direction. After being inserted into the grooves 102, the protrusions 101 form a smaller mating width at their root, preventing them from disengaging from the grooves 102 in the circumferential direction of the circumferential surface 104.

[0034] Furthermore, when the stator core 11 is assembled with the stator support 41, the circumferential surface 104 formed by the mating portions 112 of the multiple segmented cores 111 is interference-fitted with the stator support 41. This causes the multiple segmented cores 111, which are arranged together, to open up by a certain size radially along the circumferential surface 104. In other words, through the cooperation between the protrusions 101 and the grooves 102, a tighter connection is formed between the mating portions 112 of the multiple segmented cores 111.

[0035] The stator core 11 provided in some embodiments of this application is formed by splicing together segmented cores 111. The mating portions 112 of two adjacent segmented cores 111 are engaged by protrusions 101 and grooves 102, thereby surrounding each other and forming a circumferential surface 104 that is interference-fitted with the stator support 41. During the assembly of the stator core 11, the interference fit makes the fit between the protrusions 101 and the grooves 102 tighter, thereby ensuring the connection effect of each segmented core 111 during the assembly of the stator core 11.

[0036] In practice, the groove 102 can be provided on the end face or side face of the mating part 112 of the segmented iron core 111. Corresponding to the groove 102, the protrusion 101 can be provided on the end face or side face of the mating part 112 of the segmented iron core 111.

[0037] like Figure 1 and Figure 2 As shown, in some embodiments, the protrusion 101 is inserted into the groove 102 along a preset direction, and the groove 102 restricts the protrusion 101 within a plane perpendicular to the preset direction.

[0038] In other words, the protrusion 101 and the groove 102 can be provided on the side with a larger area of ​​the mating portion 112 of the segmented iron core 111. By providing the protrusion 101 and the groove 102 on the side with a larger area of ​​the mating portion 112, it can be ensured that there is a sufficiently large area for the protrusion 101 and the groove 102. This ensures that the protrusion 101 and the groove 102 have sufficient mating area.

[0039] In some embodiments, the groove 102 penetrates the mating portion 112 in a predetermined direction, and the protrusion 101 extends outward from the mating portion 112.

[0040] In other words, the groove 102 is arranged along a preset direction, and the length direction of the groove 102 is parallel to the preset direction. Simultaneously, one or both ends of the groove 102 penetrate the mating portion 112 of the segmented iron core 111. By setting the groove 102 along the preset direction, the mating length between the groove 102 and the protrusion 101 can be ensured. Forming a groove 102 of sufficient length on the surface of the mating portion 112 of the segmented iron core 111 helps ensure the connection effect between two adjacent segmented iron cores 111.

[0041] In practice, the groove 102 can be formed by both ends penetrating simultaneously to facilitate the engagement between the protrusion 101 and the groove 102. As shown in the figure, the length direction of the groove 102 is parallel to the preset direction, and the groove 102 penetrates the mating part 112 of the segmented iron core 111 at both ends. When assembling multiple segmented iron cores 111, the protrusion 101 can enter the groove 102 along the preset direction or in the opposite direction of the preset direction, thus completing the engagement process with the groove 102.

[0042] Alternatively, the maximum width of the protrusion 101 in the vertical direction of the preset direction can be greater than the width of the groove 102 at the opening perpendicular to the preset direction.

[0043] The groove 102 has a smaller width at its opening facing other segmented iron cores 111. When the protrusion 101 is inserted into the groove 102, it can limit the protrusion 101, preventing it from disengaging from the groove 102 along its depth direction. This allows the multiple segmented iron cores 111 to form a tightly connected whole in the circumferential direction around the predetermined direction.

[0044] In some embodiments, the width of the groove 102 in the vertical direction of the preset direction can be increased and then decreased in the protruding direction of the protrusion 101.

[0045] In other words, the width of the groove 102 first increases and then decreases along the depth direction, thus forming a groove 102 with a wide opening and a narrow opening. After the protrusion 101 is engaged in the groove 102, it can effectively prevent the protrusion 101 from loosening or separating. At the same time, the width of the bottom of the groove 102 decreases, which can avoid the formation of a large fitting gap.

[0046] In some embodiments, such as Figure 3 and Figure 4 As shown, the protrusion 101, the groove 102, the mating part 112 and the extension part 113 are integrally formed.

[0047] The mating portions 112 of the segmented iron cores 111 serve as the splicing and positioning parts, and the mating portions 112 of multiple segmented iron cores 111 are arranged in a ring. Grooves 102 and protrusions 101 are distributed on different sides of the mating portions 112 of each segmented iron core 111 and are located on the splicing surfaces of two adjacent segmented iron cores 111. Two adjacent segmented iron cores 111 can be positioned and connected by the engagement between the protrusions 101 and the grooves 102. When multiple segmented iron cores 111 are arranged circumferentially, the protrusion 101 of one of two adjacent segmented iron cores 111 engages with the groove 102 of the other. In practice, some segmented iron cores 111 may only have protrusions 101 on their mating portions 112, while others may only have grooves 102 on their mating portions 112. That is, one of two adjacent segmented iron cores 111 has a protrusion 101 on its mating portion 112, and the other has a groove 102 on its mating portion 112. Similarly, the splicing and combination of multiple segmented iron cores 111 can be achieved through the cooperation between the protrusion 101 and the groove 102.

[0048] In some embodiments, at least a portion of the mating portion 112 of the segmented core 111 may have a protrusion 103 on the side surface away from the extension portion 113, the protrusion 103 being used to mate with the recess on the stator support 41.

[0049] A protrusion 103 is provided on the surface of the mating portion 112 of the segmented iron core 111 away from the extension portion 113. This protrusion serves a positioning function to facilitate the assembly between the stator assembly and the stator support 41. In practice, a protrusion 103 can be provided on the surface of the mating portion 112 of each segmented iron core 111 away from the extension portion 113. Figure 4 As shown, the protrusion 103 is formed inside the mating portion 112 of the multiple segmented iron cores 111. When the stator assembly is mated with the stator support 41, the protrusion 103 can be engaged with the recess 411 on the stator support 41, thereby playing a positioning role and avoiding assembly misalignment.

[0050] In addition, the protrusion 103 may be elongated, and the length direction of the protrusion 103 is parallel to a preset direction.

[0051] In other words, the protrusion 103 is provided as a rib on the surface of the mating part 112 of the segmented iron core 111. By making the length direction of the protrusion 103 parallel to a preset direction, it can be ensured that the protrusion 103 has sufficient length. Thus, when the stator iron core 11 and the stator support 41 are mated, the mating length between them is ensured, thereby ensuring the positioning effect of the protrusion 103.

[0052] like Figure 5 and Figure 6As shown, some embodiments of this application also provide a stator assembly, which includes a stator core 11, a plurality of insulating frames 21, and a coil winding 31. The stator core 11 is the stator core 11 described above. The plurality of insulating frames 21 correspond one-to-one with the plurality of segmented cores 111, and each insulating frame 21 is fitted onto the corresponding segmented core 111. The extension portion 113 of the coil winding 31 corresponding to the segmented core 111 is disposed on each insulating frame 21.

[0053] The stator core 11 is the fundamental part of the stator assembly. It is not only a key component of the motor's magnetic circuit but also serves to fix and support the coil windings 31. When current flows through the coil windings 31, the generated magnetic field is collected and concentrated in the stator core 11, thereby enhancing and guiding it to the rotor assembly, driving the rotor assembly to rotate. The stator core 11 is formed by a segmented core arranged in a circumferential pattern. The mating portions 112 of each segmented core 111 are arranged together to form the yoke of the stator core 11, and the extensions 113 of each segmented core 111 form the teeth of the stator core 11, which can be used to arrange the coil windings 31.

[0054] The insulating frame 21 is installed on the surface of the stator core 11 by injection molding or as a set. The insulating frame 21 serves as insulation in the stator assembly, electrically isolating the stator core 11 from the coil windings 31. When winding on the insulating frame 21, due to the absence of lateral obstruction, a larger number of coils can be wound on each segment of the core 111, achieving high slot fill factor, reducing copper losses, and minimizing heat generation. After winding, the segments are installed vertically and horizontally to form a complete stator assembly.

[0055] The inner circumferential surface 104 of the stator core 11 and the outer circumference of the stator bracket 41 are interference-fitted and can be installed by press-fitting or liquid nitrogen cold pressing. After installation, the stator core 11 ensures a certain bonding force between each pair of segmented cores 111 and between each segmented core 111 and the stator bracket 41. This ensures the connection strength of the stator core 11 during assembly.

[0056] Some embodiments of this application also provide an external rotor motor, which includes the stator assembly described above.

[0057] External rotor motors can be used in various power tools, such as hammer drills, reciprocating electric saws, or trimmers. External rotor motors reduce motor costs by employing a split structure in the stator assembly. During manufacturing, the stator assembly can be divided into sections on a mold according to the teeth. This significantly increases material utilization. The sections are fitted together using inner smaller and outer larger bosses, and the installation method is axial vertical mounting, ensuring radial detachment is prevented.

[0058] Meanwhile, the circumferential surface 104 formed by the mating parts 112 of each segmented iron core 111 is interference-fitted with the outer ring of the stator bracket 41. After the stator iron core 11 is installed, it can ensure that there is a certain bonding force between each pair of segmented iron cores 111 and between segmented iron cores 111 and stator bracket 41. This ensures the connection strength of the stator iron core 11 during assembly.

[0059] 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 core, characterized in that, include: Multiple segmented iron cores are arranged around a preset direction. Each segmented iron core includes a connected mating part and an extension part. The mating part of each segmented iron core is provided with a protrusion and a groove. The protrusion and the groove are located on both sides of the circumference of each mating part. The protrusion of one of two adjacent segmented iron cores is inserted into the groove of the other, so that the mating parts of the multiple segmented iron cores are connected end to end in a circumferential shape to form a circumferential surface that is interference-fitted with the stator support.

2. The stator core according to claim 1, characterized in that: The protrusion is inserted into the groove along a preset direction, and the groove confines the protrusion within a plane perpendicular to the preset direction.

3. The stator core according to claim 2, characterized in that: The groove extends through the mating part along the preset direction, and the protrusion extends outward from the mating part.

4. The stator core according to claim 3, characterized in that: The maximum width of the protrusion in the direction perpendicular to the preset direction is greater than the width of the groove at the opening perpendicular to the preset direction.

5. The stator core according to claim 1, characterized in that: The width of the groove in the direction perpendicular to the preset direction first increases and then decreases in the protruding direction of the protrusion.

6. The stator core according to claim 1, characterized in that: The protrusion, the groove, the mating part, and the extension are integrally formed.

7. The stator core according to claim 1, characterized in that: At least a portion of the mating portion of the segmented iron core has a protruding portion on the side surface away from the extension portion, the protruding portion being used to mate with a recess on the stator support.

8. The stator core according to claim 7, characterized in that: The protrusion is elongated and its length direction is parallel to the preset direction.

9. A stator assembly, characterized in that, include: The stator core according to any one of claims 1 to 8; Multiple insulating frames correspond one-to-one with multiple segmented iron cores, and each insulating frame is fitted onto the corresponding segmented iron core. The coil windings are provided on each of the insulating frames, corresponding to the extensions of the segmented iron core.

10. An external rotor motor, characterized in that, Includes the stator assembly as described in claim 9.

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