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 stator iron core, an injection molding framework and a coil winding. 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, and the matching parts of the plurality of block iron cores are arranged together in a surrounding manner. The injection molding framework comprises an annular part arranged around the preset direction and a plurality of extension parts which are connected with the annular part and are in one-to-one correspondence with the extension parts of the plurality of block iron cores, the annular part covers the surfaces, perpendicular to the preset direction, of the matching parts of the plurality of block iron cores, and the extension parts of the corresponding block iron cores are wrapped by the plurality of extension parts. A coil winding is disposed on each epitaxial portion. 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] The embodiment of the present application relates to the motor technical field, in particular to a stator assembly and an outer rotor motor. BACKGROUND

[0002] With the continuous development of tool manufacturing technology, various electric tools for different work scenes begin to appear. The use of electric tools can improve work efficiency, and can ensure machining accuracy through control of the running state. The outer rotor motor is an important component of the electric tool, which can drive the actuator to act during the working process to achieve the corresponding machining purpose.

[0003] The outer rotor motor forms driving force through the cooperation between the stator assembly and the rotor assembly. The rotor assembly can rotate under the magnetic field of the stator assembly, and then drive the actuator to act. The structure of the stator assembly affects the complexity of the manufacturing process. Therefore, how to design the structure of the stator assembly to simplify the manufacturing form of the stator assembly is an important problem. CONTENT OF THE UTILITY MODEL

[0004] The embodiment of the present application aims to provide a stator assembly and an outer rotor motor, which can simplify the manufacturing form of the stator assembly.

[0005] To solve the above technical problems, the embodiment of the present application provides a stator assembly, which comprises a stator core, a plurality of sub-core blocks arranged around a preset direction, each of the sub-core blocks comprising a cooperation part and an extension part formed integrally, a plurality of the cooperation parts are arranged in a circumferential shape to surround the plurality of sub-core blocks to form the stator core, an injection molded framework comprising a ring-shaped part arranged around the preset direction and a plurality of extension parts connected with the ring-shaped part and corresponding to the extension parts of the plurality of sub-core blocks, the ring-shaped part covers the surface of the cooperation part perpendicular to the preset direction, and the extension part wraps the corresponding extension part, and a coil winding arranged on each of the extension parts. In some embodiments, the cooperation parts of two adjacent sub-core blocks are engaged with each other.

[0006] In some embodiments, the cooperation part of each of the sub-core blocks is respectively provided with a groove and a protrusion, and the protrusion of one of the two adjacent sub-core blocks is engaged into the groove of the other.

[0007] In some embodiments, the groove extends along the preset direction, and at least one end of the groove is provided through in the preset direction.

[0008] In some embodiments, 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.

[0009] In some embodiments, a projection of the annular portion in the preset direction covers at least part of the protrusion.

[0010] In some embodiments, the injection-molded framework further comprises a cylindrical portion connected to the annular portion, the cylindrical portion being arranged around the preset direction; the annular portion, the extension portion and the cylindrical portion are integrally formed.

[0011] In some embodiments, the fitting portion of at least part of the split core protrudes from a side surface of the extension portion to form a protrusion, the protrusion being fitted with a recess on a stator support. Embodiments of the present application further provide a stator assembly, comprising: a stator core comprising a plurality of split cores arranged around a preset direction, each of the split cores comprising an integrally formed fitting portion and an extension portion, the plurality of fitting portions being arranged in a circumferential manner to surround the plurality of split cores to form the stator core; an injection-molded framework comprising an annular portion arranged around the preset direction, and a plurality of extension portions connected to the annular portion and corresponding to the extension portions of the plurality of split cores, the injection-molded framework being integrally injection-molded to the outer surfaces of the plurality of split cores to fix the plurality of split cores; and a coil winding arranged on each of the extension portions.

[0012] Embodiments of the present application further provide an external rotor motor comprising the above-mentioned stator assembly. BRIEF DESCRIPTION OF DRAWINGS

[0013] One or more embodiments are illustrated by way of example in the figures that are part of this disclosure and which are illustrative, but not restrictive, of the present embodiments, wherein elements having the same reference number designates like elements. Figures in the drawings are not necessarily to scale, except if so expressly indicated.

[0014] Figure 1 is a perspective structural schematic diagram of a stator assembly provided by some embodiments of the present application;

[0015] Figure 2 is a top view structural schematic diagram of a stator assembly provided by some embodiments of the present application;

[0016] Figure 3 is a fitting structural schematic diagram of a stator core and an injection-molded framework in a stator assembly provided by some embodiments of the present application;

[0017] Figure 4 is a top view structural schematic diagram of a stator core and an injection-molded framework in a stator assembly provided by some embodiments of the present application;

[0018] Figure 5 is a perspective structural schematic diagram of a stator core in a stator assembly provided by some embodiments of the present application;

[0019] Figure 6 is a perspective structural schematic diagram of a split core in a stator assembly provided by some embodiments of the present application;

[0020] Figure 7 is a matching structural schematic diagram of different split cores in a stator assembly provided by some embodiments of the present application;

[0021] Figure 8 is a structural schematic diagram of a stator assembly and a stator support when they are assembled provided by some embodiments of the present application;

[0022] Figure 9 is a matching structural schematic diagram of a stator assembly and a stator support provided by some embodiments of the present application. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the embodiments of the present application will be described in detail below with reference to the drawings. However, those skilled in the art can understand that in the embodiments of the present application, many technical details are proposed in order to make the readers better understand the present application. However, the technical scheme claimed by the present application can be realized even without these technical details and various changes and modifications based on the following embodiments. The division of the following embodiments is for the convenience of description, and should not constitute any limitation on the specific embodiments of the present application, and the embodiments can be combined and referred to 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 belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "comprising" and "having" and any variations thereof in the specification and claims and the above description of the drawings are intended to cover not exclusive inclusion.

[0025] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting" and the like should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0026] Outer rotor motor and inner rotor motor are two common types of motors. In contrast to the inner rotor motor, the coil of the outer rotor motor is on the inside and the magnet is on the outside, which is a kind of motor that rotates the outside. Compared with the inner rotor motor, the moment of inertia of the rotating shaft of the outer rotor motor is larger, which is convenient for maintenance and has advantages in the winding operation of the coil. Therefore, the outer rotor motor is widely used in various electric tools as a power source to drive the action of the execution component.

[0027] The stator assembly is an important component of the motor, and the coil winding of the stator assembly can generate a magnetic field under the condition of power supply, thereby exciting the rotor assembly to rotate. The stator assembly includes a stator core, an insulation framework and a coil winding. At present, the stator core in the stator assembly of the outer rotor motor mainly includes an integral type and a split type. When the integral stator core is used, the inner ring of the stator assembly is in interference fit with the aluminum support. Because there is no special positioning, it is easy to be pressed or misaligned during the production process. In addition, the stator core is a one-piece circular structure, and after winding each slot, the stator core is rotated to start winding the next slot. The defects in the production process will cause all previous processes to fail, resulting in huge scrap costs. When the split stator core is used, the stator core needs to be welded at the connection by laser welding or argon arc welding, which is a complex process.

[0028] In order to simplify the manufacturing form of the stator assembly, some embodiments of the present application provide a stator assembly. The stator core is made into a split structure on the mold according to the teeth, and the split manufacturing form can greatly increase the utilization of materials. After the split core is completed, the split core can be arranged in a circular manner and placed in the mold for injection molding to form an injection molding framework on the surface of the split core. The injection molding framework can fix different blocks of the split core, and then perform winding on each tooth of the stator core to form a stator assembly after the framework is formed. Thus, the complex welding process is avoided, which is beneficial to simplify the manufacturing form of the stator assembly.

[0029] The structure of the stator assembly provided by some embodiments of the present application will be described below. Figures 1 to 7

[0030] As shown in Figures 1 to 7 some embodiments of the present application provide a stator assembly including a stator core 11, an injection molding framework 12 and a coil winding 13. The stator core 11 includes a plurality of teeth 111 arranged in a predetermined direction (e.g., circumferentially) around the stator core 11. The teeth 111 of the stator core 11 are arranged in a split structure. The injection molding framework 12 is arranged on the surface of the stator core 11. The coil winding 13 is arranged on each tooth 111 of the stator core 11. Figure 1 ​The plurality of split cores 111 are arranged in a preset direction (indicated by the arrow X), each of the split cores 111 comprises a fitting part 112 and an extension part 113 which are integrally formed, and the fitting parts 112 of the plurality of split cores 111 are arranged around each other. The injection molded skeleton 12 comprises a ring-shaped part 121 arranged in the preset direction, and a plurality of extension parts 122 connected with the ring-shaped part 121 and corresponding to the extension parts 113 of the plurality of split cores 111, the ring-shaped part 121 covers the surface of the fitting parts 112 of the plurality of split cores 111 which is perpendicular to the preset direction, and the plurality of extension parts 122 wrap the extension parts 113 of the corresponding split cores 111. The coil winding 13 is arranged on each of the extension parts 122.

[0031] The stator core 11 is the base part of the stator assembly, and is not only the key part of the magnetic circuit of the motor, but also serves to fix and support the coil winding 13. When the current passes through the coil winding 13, the magnetic field generated is collected and concentrated in the stator core 11, and then is enhanced and guided to the rotor assembly, so as to drive the rotor assembly to rotate. The stator core 11 is formed in a circumferential arrangement by split cores. The fitting parts 112 of each of the split cores 111 are arranged around each other to form the yoke part of the stator core 11, and the extension parts 113 of each of the split cores 111 form the tooth part of the stator core 11, which can be used to arrange the coil winding 13.

[0032] The injection molded skeleton 12 is formed on the surface of the stator core 11 by injection molding. The injection molded skeleton 12 serves an insulation function in the stator assembly, and can electrically isolate the stator core 11 and the coil winding 13. The injection molded skeleton 12 comprises the ring-shaped part 121 and the extension part 122 which are connected, the ring-shaped part 121 wraps from the outside of the fitting parts 112 of the plurality of split cores 111, and can be used in cooperation with the extension part 122 to fix the plurality of split cores 111. The ring-shaped part 121 covers one side end surface of the fitting parts 112 of the plurality of split cores 111, or the ring-shaped part 121 is formed by injection molding on both side end surfaces of the fitting parts 112 of the plurality of split cores 111. The extension part 122 wraps the tooth part of the stator core 11, and corresponds to the position where the coil winding 13 is arranged. In actual cases, the injection molded skeleton 12 can also cover the side surface of the fitting part 112 of each of the split cores 111 which is close to the extension part 113, i.e. the surface which is parallel to the preset direction, so as to improve the fixing effect of the plurality of split cores 111.

[0033] The stator assembly provided by some embodiments of the present application adopts the split core 111 to combine to form the stator core 11, and sets the injection molded framework 12 on the surface of the stator core 11. The annular part 121 of the injection molded framework 12 can wrap the fitting part 112 of the plurality of split cores 111, so as to fix the different split cores 111 in cooperation with the extension part 122. The coil winding 13 can be arranged on the extension part 122 set by the injection molded framework 12 corresponding to each split core 111. Thus, the connection part of the split core 111 does not need to be fixed by using a complex process such as welding, and the manufacturing form of the stator assembly is simplified.

[0034] In some embodiments, the fitting parts 112 of the two adjacent split cores 111 can be clamped together.

[0035] That is, the different split cores 111 can be positioned in the form of clamping splicing. Each split core 111 can be spliced into an integral whole in the form of clamping to ensure the positioning effect in the subsequent injection molding fixing process. At the same time, the clamping action can also strengthen the connection effect between the different split cores 111. The clamping form can be the cooperation form of shaft holes, the cooperation form of protrusions 101 and grooves 102, or the cooperation form of locking pins and sliding grooves.

[0036] As shown in Figures 5 to 7 each fitting part 112 of the split core 111 can be respectively provided with a groove 102 and a protrusion 101, and the protrusion 101 of one of the two adjacent split cores 111 is clamped into the groove 102 of the other.

[0037] The fitting part 112 of the split core 111 is the splicing positioning part, and the fitting parts 112 of the plurality of split cores 111 are formed in a ring shape by surrounding. The grooves 102 and the protrusions 101 are distributed on different sides of the fitting part 112 of each split core 111 and located on the splicing surfaces of the two adjacent split cores 111. The two adjacent split cores 111 can be positioned and connected through the cooperation between the protrusions 101 and the grooves 102. When the plurality of split cores 111 are arranged in a circumferential shape, the protrusion 101 of one of the two adjacent split cores 111 is clamped into the groove 102 of the other. In actual cases, the fitting part 112 of part of the split cores 111 can be provided with only the protrusion 101, and the fitting part 112 of part of the split cores 111 can be provided with only the groove 102. That is, the fitting part 112 of one of the two adjacent split cores 111 is provided with the protrusion 101, and the fitting part 112 of the other is provided with the groove 102. The cooperation between the protrusion 101 and the groove 102 can also be used to realize the splicing combination of the plurality of split cores 111.

[0038] In some embodiments, the groove 102 can extend along a preset direction, and at least one end of the groove 102 can be arranged to penetrate through the fitting portion 112 of the split iron core 111 in the preset direction.

[0039] That is, the groove 102 is arranged along a preset direction, and the length direction of the groove 102 is parallel to the preset direction. Meanwhile, one end or both ends of the groove 102 penetrate through the fitting portion 112 of the split iron core 111. By arranging the groove 102 along the preset direction, the fitting length between the groove 102 and the protrusion 101 can be ensured. The groove 102 with sufficient length can be formed on the surface of the fitting portion 112 of the split iron core 111, which is beneficial to ensure the connection effect between the adjacent two split iron cores 111.

[0040] In actual cases, the groove 102 can be arranged to penetrate through both ends, so as to fit the protrusion 101 and the groove 102. As shown in Figure 5 and Figure 6 , the length direction of the groove 102 is parallel to the preset direction, and the groove 102 penetrates through both ends of the fitting portion 112 of the split iron core 111. When the plurality of split iron cores 111 are spliced and combined, the protrusion 101 can enter the groove 102 along the preset direction or the opposite direction of the preset direction, and the protrusion 101 and the groove 102 can be fitted.

[0041] In addition, the maximum width of the protrusion 101 in the direction perpendicular to the preset direction can be greater than the width of the groove 102 at the opening facing the direction perpendicular to the preset direction.

[0042] That is, the groove 102 is arranged to have a smaller width at the opening facing the other split iron core 111. When the protrusion 101 is inserted into the groove 102, the protrusion 101 can be limited. The protrusion 101 cannot be separated from the groove 102 along the depth direction of the groove 102. Thus, in the circumferential direction around the preset direction, the plurality of split iron cores 111 can be connected closely to form a whole. As shown in Figure 6 , the width of the groove 102 can first increase and then decrease along the depth direction, so as to form a groove 102 with a wide opening inside and a narrow opening outside. After the protrusion 101 is inserted into the groove 102, the protrusion 101 can be effectively prevented from being separated. Meanwhile, the injection-molded skeleton 12 can prevent the plurality of split iron cores 111 from being separated in the preset direction and the circumferential direction around the preset direction.

[0043] In some embodiments, the projection of the annular portion 121 in the preset direction can cover at least part of the protrusion 101.

[0044] The annular portion 121 comprises a cylindrical portion wrapped from the outer side of the fitting portion 112 of the plurality of split iron cores 111, and an annular portion 121 covering the end surface of the fitting portion 112 of the plurality of split iron cores 111. The plurality of split iron cores 111 are wrapped by the cooperation between the two portions to fix the plurality of split iron cores 111. By making the projection of the annular portion 121 in the preset direction cover at least part of the protrusion 101, the coverage area of the annular portion 121 can reach the position of the protrusion 101. Thus, the radial wrapping length of the annular portion 121 on the end surface of the plurality of split iron cores 111 is ensured, which is beneficial to ensure the fixing effect of the plurality of split iron cores 111 in the preset direction.

[0045] As shown in Figures 1 to 4 , the injection molded framework 12 can further comprise a cylindrical portion 123 connected with the annular portion 121, and the cylindrical portion 123 is arranged around the preset direction.

[0046] The cylindrical portion 123 is formed at the end position of the annular portion 121 in the preset direction, and the cylindrical portion 123 is higher than the split iron core 111 in the preset direction. The circumferential surface formed on the inner side of the cylindrical portion 123 can provide a positioning basis for the assembly of the mounting piece, so as to assemble the stator assembly.

[0047] In actual cases, the annular portion 121, the extension portion 122 and the cylindrical portion 123 can be integrally formed.

[0048] That is, when the injection molding fixing process of the stator core 11 is performed, the annular portion 121, the extension portion 122 and the cylindrical portion 123 can be formed at the same time, so as to ensure the overall structural strength of the injection molded framework 12 and the fixing effect of the injection molded framework 12 on the plurality of split iron cores 111.

[0049] In some embodiments, the fitting portion 112 of at least part of the split iron core 111 is provided with a protrusion 103 protruding from the side surface of the extension portion 113, and the protrusion 103 is used to cooperate with the recess 211 on the stator support 21.

[0050] By arranging the protrusion 103 on the circumferential surface 104 of the fitting portion 112 of the split iron core 111 away from the extension portion 113, the positioning effect can be achieved, so as to assemble the stator assembly and the stator support 21. In actual cases, the protrusion 103 can be arranged on the side surface of the fitting portion 112 of each split iron core 111 away from the extension portion 113. As shown in Figure 5 , the protrusion 103 is formed on the inner side of the fitting portion 112 of the plurality of split iron cores 111. As shown in Figure 8 and Figure 9As shown, when the stator assembly is fitted with the stator support 21, the protrusion 103 can be clamped into the recess 211 on the stator support 21, thereby playing a positioning role to avoid misalignment during assembly.

[0051] Some embodiments of the present application also provide an outer rotor motor, which comprises the above-described stator assembly.

[0052] The outer rotor motor can be applied to various electric tools, such as electric hammers, reciprocating electric saws or edge trimmers. The outer rotor motor can reduce the cost of the motor by adopting a split structure in the stator assembly. When the stator assembly is manufactured, the teeth can be made into a split structure on a mold. Then the split core is arranged in a circumferential manner and placed into the mold for injection molding, so as to form an injection skeleton 12 on the surface of the split core 111. The skeleton can fix different blocks of the core, and after the skeleton is formed, the winding can be performed on each tooth of the stator core 11 to form a coil winding 13. Thus, the split core 111 does not need to be connected and fixed by using a complex process such as welding, thereby simplifying the manufacturing form of the stator assembly.

[0053] Those skilled in the art can understand that the above-mentioned embodiments are specific embodiments for implementing the present application, and in actual applications, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. A stator assembly, characterized in that, include: The stator core includes multiple segmented cores arranged around a preset direction. Each segmented core includes an integrally formed mating part and an extension part. The multiple mating parts are arranged in a circumferential shape to surround the multiple segmented cores to form the stator core. The injection-molded skeleton includes an annular portion arranged around the preset direction, and a plurality of extended portions connected to the annular portion and corresponding one-to-one with the extension portions of the plurality of segmented iron cores. The annular portion covers the surface of the mating portion perpendicular to the preset direction, and the extended portions wrap around the corresponding extension portions. A coil winding is provided on each of the said extension portions.

2. The stator assembly according to claim 1, characterized in that: The mating parts of two adjacent segmented iron cores engage with each other.

3. The stator assembly according to claim 2, characterized in that: Each of the segmented iron cores has a groove and a protrusion in its mating part, and the protrusion of one of two adjacent segmented iron cores is engaged with the groove of the other.

4. The stator assembly according to claim 3, characterized in that: The groove extends along the preset direction, and at least one end of the groove is disposed through the preset direction.

5. The stator assembly according to claim 4, 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.

6. The stator assembly according to claim 5, characterized in that: The projection of the annular portion in the preset direction at least covers a portion of the protrusion.

7. The stator assembly according to claim 1, characterized in that: The injection-molded skeleton also includes a cylindrical portion connected to the annular portion, the cylindrical portion being arranged around the preset direction; the annular portion, the extended portion and the cylindrical portion are integrally formed.

8. The stator assembly according to claim 1, characterized in that: At least a portion of the mating portion of the segmented iron core protrudes from the side surface away from the extension to form a protrusion, which mates with a recess on the stator support.

9. A stator assembly, characterized in that, include: The stator core includes multiple segmented cores arranged around a preset direction. Each segmented core includes an integrally formed mating part and an extension part. The multiple mating parts are arranged in a circumferential shape to surround the multiple segmented cores to form the stator core. The injection-molded skeleton includes an annular portion arranged around the preset direction, and a plurality of extended portions connected to the annular portion and corresponding one-to-one with the extension portions of the plurality of segmented iron cores. The injection-molded skeleton is integrally injection-molded onto the outer surface of the plurality of segmented iron cores to fix the plurality of segmented iron cores together. A coil winding is provided on each of the said extension portions.

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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