Rotor structure and motor

Abstract

The utility model relates to a rotor structure for a motor, which is provided with a rotor iron core, the rotor iron core comprises first punching sheets (1) and second punching sheets (2), the first punching sheets (1) are located at two axial ends of the rotor iron core, the second punching sheets (2) are located in the middle of the rotor iron core, and the first punching sheets (1) are located at two axial ends of the rotor iron core. The first punching sheet (1) and the second punching sheet (2) are provided with magnet grooves (11, 21) used for placing a magnet (3), the second punching sheet (2) is provided with an accommodating groove (22) at the position of the magnet groove (21) corresponding to the periphery of the magnet (3), the first punching sheet (1) shields the accommodating groove (22) in the axial direction, a foaming material (4) used for fixing the magnet (3) is arranged in the accommodating groove (22), and the foaming material (4) is used for fixing the magnet (3). Therefore, the magnet is fixed by the foaming material.

Description

Technical Field

[0001] This utility model relates to the field of electric vehicle drive motor technology, and focuses on the innovation and improvement of motor rotor structure and related manufacturing processes, aiming to ensure that the motor rotor magnet can be fixed firmly and efficiently, thereby improving the operational stability and reliability of the entire motor system. Background Technology

[0002] In the field of electric vehicle drive motors, the methods for fixing rotor magnets have continuously evolved to achieve the goals of reducing costs and increasing power density. With increasingly demanding motor performance requirements, cooling oil needs to flow through the magnet slots to enhance cooling efficiency, necessitating the provision of gaps in the magnet slots for oil flow. Simultaneously, the rotor's operating conditions are extremely harsh, placing stringent requirements on the magnet fixing method. Specifically, the fixing method must possess high-temperature resistance and high material mechanical strength to withstand the centrifugal forces generated during high-speed rotor operation.

[0003] Currently, common methods for fixing magnets mainly include applying glue, riveting, and using foam materials.

[0004] The adhesive application method involves applying glue to the main contact surfaces of the magnet. This method preserves the gaps in the magnet slots, but it has many drawbacks. Due to the extremely high performance requirements of the glue, the glue is expensive, and the application and subsequent curing processes require additional labor time, increasing the overall process time and material costs.

[0005] The riveting method involves deforming the rotor core to make riveting contact with the magnet. This method requires no additional materials, is low in cost, and is fast. However, this method will increase motor losses, which will negatively affect motor performance and further reduce its performance.

[0006] The application of foamed materials in the field of motors is still relatively new. Currently, some methods of fixing rotor magnets with foamed materials typically involve pre-embedding the foamed material and then performing a subsequent heating and curing process. However, existing foamed material fixing methods have drawbacks. In some embodiments, the magnet is wrapped with foamed material and placed in the magnet groove, which increases the gap between the magnet and the iron core, inevitably leading to a decrease in motor performance. Furthermore, overflow at the end face is prone to occur during foaming, affecting the normal operation and service life of the motor.

[0007] In summary, all existing magnet fixing solutions have problems to varying degrees. Therefore, there is an urgent need for a new magnet fixing solution that can not only meet the requirement of leaving the magnet slot empty, but also achieve ideal requirements in terms of high temperature resistance, high strength, low cost, high efficiency, and ensuring motor performance. Utility Model Content

[0008] The technical problem to be solved by this utility model is to provide an improved rotor structure that can fix the magnet in a high-temperature resistant, high-strength and low-cost manner through an improved fixing method, thereby solving the technical problems in the prior art and achieving significant progress in ensuring motor performance, controlling costs and optimizing processes.

[0009] The aforementioned technical problem is solved by an improved rotor structure. This rotor structure features a unique rotor core construction, consisting of a first lamination and a second lamination that are not entirely identical. The first lamination is located at both axial ends of the rotor core, while the second lamination is located in the middle. Both the first and second laminations have magnet slots for accommodating magnets. This layout provides the foundation for magnet fixation and overall rotor performance optimization. The second lamination has receiving slots at positions corresponding to the magnet slots around the magnet. The first lamination axially blocks these receiving slots, and foam material for fixing the magnets is placed within them. The receiving slots, positioned around the magnets, do not obstruct the distribution of magnetic lines of force or encroach on the main magnetic circuit. The axial blocking effect of the first lamination creates a relatively enclosed space, preventing the foam material within the receiving slots from overflowing axially during magnet insertion or other operations, thus ensuring the stability and reliability of the receiving slot structure. When foamed material is placed into the receiving groove, this groove structure ensures that the foamed material is accurately positioned, providing stable support for the magnet's fixation. This helps to securely fix the magnet in the rotor, thereby improving the overall structural strength and operational stability of the rotor. After the magnet is inserted, the foamed material and the magnet make elastic contact, generating a certain amount of fixing force. No additional fixing measures are needed during the process. After overall heating, the foamed material solidifies, further fixing the magnet. This makes the rotor structure suitable for high-temperature and high-intensity working environments, further improving rotor performance.

[0010] According to a preferred embodiment of this utility model, the magnet slot is elongated and has a long side mating surface and a wide side mating surface that match the shape of the magnet, with open portions at both ends. This elongated design is compatible with the conventional shape of the magnet, ensuring that the magnet can be accurately and stably placed in the magnet slot. The long side mating surface and the wide side mating surface of the magnet can fit tightly against the magnet after insertion, providing good contact and positioning, which is beneficial for the magnet to exert stable electromagnetic performance during rotor operation. The open portions at both ends provide a certain space allowance for the magnet under conditions such as thermal expansion, avoiding excessive compression of the magnet due to thermal expansion and contraction, which could affect its performance or cause structural damage. Preferably, the receiving groove is located in the corner area between the long side mating surface and the wide side mating surface of the magnet. The inclusion of a receiving groove in this corner area serves two purposes: firstly, it fully utilizes the relatively spacious area within the magnet slot, avoiding interference with the main magnet placement area; secondly, it allows the foamed material to apply uniform pressure to the magnet from the side after filling the receiving groove, generating effective friction when the magnet is inserted, thus achieving a stable fixation effect. Further preferably, the receiving groove is located within the bend of the open section. This design further optimizes the placement of the receiving groove. The bend of the open section is typically a stress-concentrated area in the magnet slot structure; placing the receiving groove here can alleviate this stress concentration to some extent, while also preventing stress concentration caused by the addition of the receiving groove.

[0011] According to a preferred embodiment of this utility model, the receiving groove is a semi-open groove, with its opening facing the magnet. The semi-open groove design facilitates the pre-placement of the foam material, allowing for easy placement of the foam material into the receiving groove during assembly, and also guides the magnet and foam material to interact correctly when the magnet is inserted. During magnet insertion, the semi-open groove structure causes the foam material to be gradually compressed and deformed, and the resulting frictional force helps to prevent the movement of the magnet, thus achieving stable fixation of the magnet. More preferably, the receiving groove has a circular shape with an opening portion less than 1 / 2 of a circle. The circular shape makes the internal space of the receiving groove relatively regular, which is conducive to the uniform distribution of the foam material within it, and generates a relatively uniform reaction force when compressed. The design of the opening portion being less than 1 / 2 of a circle, while ensuring convenient placement of the foam material, effectively limits the movement range of the foam material when not compressed by the magnet, preventing it from accidentally detaching from the receiving groove during rotor assembly or transportation. Even more preferably, after the circular outline of the receiving groove is closed, the resulting circle intersects with the magnet. This intersecting relationship ensures that when the magnet is inserted into the receiving groove, it will inevitably interact closely with the foam material. When the magnet is inserted into and compresses the foam material, the foam material will generate strong deformation and reaction force in this area because the circular outline intersects with the magnet after closing, thus forming an effective frictional force that prevents the magnet from moving further and fixes the magnet in place.

[0012] According to a preferred embodiment of this utility model, the elastic cylindrical foam material, as an optional type of foam material, possesses unique performance advantages. The elastic cylindrical structure allows the foam material to maintain a certain degree of shape stability when uncompressed, facilitating placement and positioning within the receiving groove. Furthermore, it is preferable that the film foam material is formed into an elastic cylindrical shape through folding or rolling, providing greater flexibility in the selection of foam materials. The film material itself possesses a certain degree of flexibility and plasticity, and through folding or rolling, it can be customized according to the actual shape and size of the receiving groove, enabling it to better adapt to the spatial requirements of the receiving groove.

[0013] Furthermore, the technical problem to be solved by this utility model can also be solved by an electric motor having a rotor structure including the above-mentioned features.

[0014] In summary, compared to adhesive application, although this invention requires processing of two types of laminations and foaming materials during the material preparation stage, it saves the long waiting time for adhesive application and curing during the process, reducing labor costs and avoiding the instability of fixing effect caused by fluctuations in adhesive performance. Compared to riveting, although the overall cost is slightly higher, it has significant advantages in motor performance, preventing increased motor losses due to core deformation and ensuring efficient motor operation. Compared to conventional foaming fixing solutions, this invention optimizes the lamination structure and receiving groove design, avoiding the need for opening holes or increasing gaps in the main magnetic circuit, preventing performance degradation, and effectively solving the end-face overflow problem, thus improving product quality and stability. Overall, this invention demonstrates unique technical advantages in the field of motor rotor magnet fixing, providing strong support for the further development of motor technology. Attached Figure Description

[0015] The preferred embodiments of this utility model are further illustrated below with reference to the accompanying drawings. The drawings are as follows:

[0016] Figure 1 A cross-sectional view of the lamination designed according to this utility model is shown;

[0017] Figure 2 A partially enlarged view of the second lamination is shown;

[0018] Figure 3 A partially enlarged view of the first lamination is shown;

[0019] Figure 4 An enlarged view of the magnet slot of the second lamination is shown.

[0020] Unless otherwise stated, the "axial", "radial" and "circumferential" directions mentioned in this utility model are all relative to the rotation axis of the rotor. Detailed Implementation

[0021] Rotor cores are typically composed of stacked rotor laminations. The rotor core designed according to this invention includes two types of rotor laminations: a first lamination 1 and a second lamination 2. The first lamination 1 is positioned at both axial ends of the rotor core, and the second lamination 2 is placed in the middle of the rotor core. The first lamination 1 can be a conventional lamination without any special structure; this invention mainly improves upon the second lamination.

[0022] Figure 1 A cross-sectional view of a lamination designed according to this utility model is shown. This lamination is a second lamination 2. The second lamination 2 has a plurality of magnet slots 21 evenly distributed on its circumference. These magnet slots 21 are arranged in a V-shape to hold magnets. In addition, heat dissipation holes 23 are provided between the magnet slots 21.

[0023] Figure 2This shows a partially enlarged view of the second lamination 2. Figure 3 A partially enlarged view of the first lamination 1 is shown. Comparing the second lamination 2 with the first lamination 1 reveals that the only difference is the presence of an additional receiving groove 22 at the intersection of the magnet's wide-side mating surface 211 and long-side mating surface 212 on both sides of the magnet slot 21. All other shapes are identical to the first lamination 1. The first lamination 1 is made of solid material at the location of the receiving groove 22, thus enabling it to axially shield the receiving groove 22. For the rotor core, the first lamination 1, positioned at both axial ends, creates a relatively enclosed space through its axial shielding effect, preventing the foamed material within the receiving groove 22 from overflowing axially during magnet insertion or other operations, thereby ensuring the stability and reliability of the receiving groove structure.

[0024] Figure 4 This is an enlarged view of the magnet slot 21 of the second lamination 2. A magnet 3 is placed in this magnet slot 21. In this embodiment, the receiving slot 22 of the second lamination 22 is set as a circular groove. The receiving slot 22 is located on the inner diameter side of the magnet slot 21, and in the area at the rounded corner between the long side mating surface 212 and the wide side mating surface 211 of the magnet. The receiving slot 22 is designed as a semi-open slot, and the opening portion is less than 1 / 2 of the circumference. After the outline of the receiving slot 22 is extended and closed, the circle formed has a partial volume intersection with the magnet 3 at the opening portion. Foam material 4 is placed in the receiving slot 22. Since the receiving slot 22 has a circular shape in this embodiment, the foam material 4 can be a specially customized elastic cylindrical material, or a thin film material with less elasticity can be formed into an elastic cylindrical shape by folding or rolling, so that the foam material 4 can be placed in the cylindrical groove formed by stacking the receiving slots 22. When magnet 3 is inserted into magnet slot 21, the elastic foam material 4 is compressed, generating a certain frictional force. No additional equipment or tooling is needed to reinforce or support the magnet. During operation, the material foams and solidifies as the entire device heats up, further securing magnet 3. Simultaneously, the circular receiving groove 22 on the second lamination 2 and the first lamination 1 form a semi-closed cavity axially. This means the first lamination 1 axially blocks the receiving groove 22, preventing the foam material 4 from being axially ejected from the cavity when magnet 3 is inserted. Because the foam material 4 is placed in a small section in the middle of the rotor core and is wrapped by the first lamination 1 at both axial ends, no material overflows onto the core end face when the foam material 4 is heated, preventing additional cleaning issues.

[0025] In an embodiment of this utility model, the position of the receiving groove 22 is as follows: Figure 4As shown. In this embodiment, since the empty portion 24 bends downward, the receiving groove 22 is located in the bending area, avoiding stress concentration. However, the position of the receiving groove 22 is not limited to this embodiment. The receiving groove 22 can also be located at other positions around the magnet groove 21, as long as the foam material in the receiving groove 22 can play a role in fixing the magnet 3. The magnet wide side mating surface 211 of the second punch 2 can be offset to both sides to avoid contact with the magnet 3, playing a limiting role; the magnet groove 21 can also follow the shape of the first punch 1, retaining the limiting role, while only needing to additionally process the receiving groove 22.

[0026] While possible embodiments have been described exemplarily in the foregoing description, it should be understood that numerous variations of the embodiments exist through combinations of all known and readily conceived technical features and implementation methods. Furthermore, it should be understood that the exemplary embodiments are merely examples and do not in any way limit the scope, application, or construction of this invention. The foregoing description is more intended to provide those skilled in the art with technical guidance for transforming at least one exemplary embodiment, wherein various changes can be made, particularly regarding the function and structure of the components, without departing from the scope of the claims.

[0027] List of reference numerals

[0028] 1. First film processing

[0029] 11 Magnet slot

[0030] 2 Second film processing

[0031] 21 Magnet slots

[0032] 211 Magnet wide-side mating surface

[0033] 212 Long side mating surface of magnet

[0034] 22 Receiving Tank

[0035] 23 ventilation holes

[0036] 24. Empty space

[0037] 3. Magnet

[0038] 4. Foaming materials

Claims

1. A rotor structure for an electric motor, comprising a rotor core including a first lamination (1) and a second lamination (2), wherein the first lamination (1) is located at both axial ends of the rotor core, and the second lamination (2) is located in the middle of the rotor core, wherein, The first punch (1) and the second punch (2) have magnet slots (11, 21) for accommodating magnets (3). The second punch (2) has a receiving groove (22) in the magnet slot (21) at a position corresponding to the periphery of the magnet (3). The first punch (1) blocks the receiving groove (22) in the axial direction. Foam material (4) for fixing the magnet (3) is placed in the receiving groove (22).

2. The rotor structure according to claim 1, characterized in that, The magnet groove (21) is elongated and has a magnet long side mating surface (212) and a magnet wide side mating surface (211) for matching the shape of the magnet (3). Empty portions (24) are provided at both ends of the magnet groove (21).

3. The rotor structure according to claim 2, characterized in that, The receiving groove (22) is located in the corner region between the long side mating surface (212) of the magnet and the wide side mating surface (211) of the magnet.

4. The rotor structure according to claim 3, characterized in that, The receiving groove (22) is located in the bending area of ​​the empty part (24).

5. The rotor structure according to any one of claims 1 to 4, characterized in that, The receiving groove (22) is a semi-open groove that opens toward the magnet (3).

6. The rotor structure according to claim 5, characterized in that, The receiving groove (22) has a circular shape, with an opening portion less than 1 / 2 circle.

7. The rotor structure according to claim 6, characterized in that, After the circular outline of the receiving groove (22) is closed, the resulting circle intersects with the magnet (3).

8. The rotor structure according to any one of claims 1 to 4, characterized in that, The foaming material (4) is an elastic cylindrical foaming material.

9. The rotor structure according to any one of claims 1 to 4, characterized in that, The foaming material (4) is a thin film foaming material, which is formed into an elastic column by folding or rolling.

10. An electric motor, characterized in that, The motor has the rotor structure as described in any one of claims 1 to 9.

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