A manufacturing method of a spoke-type rotor core

Abstract

The present invention discloses a manufacturing method of a spoke-type rotor core, which is processed on a continuously pushed electrical steel strip. The steps are as follows: continuously stamping support pieces to stack and self-rivet to obtain a support. The support pieces are annular and are all punched with a first central hole and rivet perforations that surround the first central hole and are circumferentially spaced; continue to layer by layer punch out a plurality of permanent magnet slot holes that are circumferentially evenly distributed to obtain a core sub-body formed by stacking and self-riveting multiple layers of sector-shaped iron cores in a ring arrangement. The multiple core sub-bodies are evenly and orderly stacked and riveted on the support at circumferential intervals. Among them, a plurality of sector-shaped iron cores in each layer enclose a second central hole, and rivet perforations are punched at circumferential intervals on the plurality of sector-shaped iron cores in each layer around the second central hole. The bottom of each permanent magnet slot facing the support between adjacent core sub-bodies is closed by the support; blanking in the mold to obtain a spoke-type rotor core formed by integral stacking and riveting, which is simple in manufacturing, simplifies the process, realizes high-frequency operation, and has high work efficiency.

Description

Technical Field

[0001] The present invention relates to a manufacturing method of a spoke-type rotor core, belonging to the technical field of manufacturing of inner-rotor permanent magnet motors.

Background Art

[0002] Please refer to the application No. 202011461073.2, and the patent name is Motor Rotor and Permanent Magnet Synchronous Motor. This rotor is used for an inner-rotor permanent magnet synchronous motor. The patent discloses that the motor rotor is composed of a split-combined outer rotor core and an inner rotor core 1 with corresponding stacked thickness. Due to different structures, the outer rotor core and the inner rotor core 1 need to be separately processed and manufactured inefficiently and at high cost on different punching dies and in different processes. Among them, the outer rotor core must be composed of 10 core units 9. Since each core unit 9 needs to be stacked and riveted individually, the outer rotor core has the disadvantage of low cumulative processing efficiency. And during the process of assembling the outer rotor assembly 2, these 10 core units 9 need to use auxiliary tooling to be sorted and positioned, and the outer rotor assembly 2 needs to be injection-molded to form an integral body with the inner rotor core 1. In short, the structure of this rotor core is complex, the processing procedures are numerous, the unit production capacity is small, so the cost is high, and the matching and limiting structure between the inner rotor core 1 and the outer rotor assembly 2 is complex, increasing the processing difficulty and processing procedures of the rotor core and restricting the improvement of production capacity.

[0003] In addition, since the installation groove for embedding the permanent magnet penetrates the entire outer rotor core, two end covers are required for rotor assembly to limit the permanent magnet within the outer rotor core, or the permanent magnet 10 and the outer rotor core need to be injection-molded into an integral body through the plastic sealing material 13, which adds another injection-molding process.

Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a manufacturing method of a spoke-type rotor core with completely integral stacked riveting connection, which can be automatically arranged in a ring during the process of stacked self-riveting, improving the efficiency of neat sorting and stacked riveting, without stacking and riveting one by one and then sorting one by one, and having the characteristic of fewer procedures.

[0005] For this purpose, the present invention provides the following technical solutions:

[0006] A manufacturing method of a spoke-type rotor core, which is used for an inner-rotor permanent magnet motor and is processed on a continuously pushed electrical steel strip, successively including the following steps: a) Self-riveting support: Continuously punch a plurality of support pieces. The support pieces are stacked and self-locked and riveted to obtain a support. Among them, the support pieces are circular rings, and each support piece is punched with a first central hole and rivet through holes punched at intervals along the circumferential direction around the first central hole. The support forms a first central shaft hole on the basis of the first central hole and forms an axial through hole on the basis of the rivet through holes.

[0007] b) Stacking and riveting the iron core body on the support: Continuously punch out a plurality of permanent magnet slot holes with evenly distributed circumferential intervals layer by layer, obtaining a plurality of iron core sub-bodies formed by self-locking and riveting connection of multiple layers of fan-shaped iron core sheets arranged in a ring. The plurality of iron core sub-bodies are stacked and riveted on the support in an evenly ordered manner with circumferential intervals. Among them, a plurality of fan-shaped iron core sheets in each layer enclose a second central hole, and rivet perforations are punched along the circumferential intervals on the plurality of fan-shaped iron core sheets in each layer around the second central hole. The bottom of each permanent magnet slot with a circumferential interval between adjacent iron core sub-bodies facing the support is closed by the support.

[0008] c) Blanking from the progressive die to obtain a fully integrated stacked and riveted formed spoke-type rotor core.

[0009] Preferably, the support in step a) and the iron core body in step b) are processed on a progressive die.

[0010] The support and the iron core body are both processed in the same die, which can reduce the die opening cost and minimize the processing links, thereby reducing the processing cost of the product.

[0011] Preferably, in step a), small through holes for filling resin are punched at circumferential intervals near the first central hole on each support piece. The support forms small axial through holes on the basis of the small through holes. The above small axial through holes are all within the circumference of the second central shaft hole surrounded by a plurality of iron core sub-bodies. The second central shaft hole and the first central hole are combined into a stepped through hole.

[0012] After opening the small axial through holes for filling resin, the shoulder end face of the rotor shaft after assembly can be adhesively fixed to the stepped surface, and the side surface of the rotor shaft can be adhesively fixed to the inner peripheral wall of the iron core body. Finally, the axial fixing strength between the rotor shaft and the support and the circumferential fixing strength between the rotor shaft and a plurality of iron core sub-bodies are realized, thereby improving the reliability of the integrated high-speed rotation of the rotor shaft and the spoke-type rotor core; abandoning the press-fitting of the rotor shaft can avoid adverse mutual damage to the rotor shaft and the rotor core.

[0013] Preferably, both the inner and outer ends of each permanent magnet slot hole in step b) are open or the inner end is open.

[0014] When both the inner and outer ends of the permanent magnet slot hole are designed to be open or the inner end is designed to be open, it is beneficial to reduce magnetic leakage. Moreover, under the condition of loading equal amounts of magnetic materials in the permanent magnet slot, the single-pole magnetic flux of the rotor can be increased, thereby greatly improving the performance of the motor.

[0015] The present invention has the following advantages and positive effects:

[0016] The support is formed by stacking and self-riveting. As a platform for the support arrangement and riveting fixation during the processing of multiple iron core sub-bodies, it cooperates with the punching and forming of multiple permanent magnet slots with uniform circumferential spacing. Therefore, every time multiple permanent magnet slot holes with uniform circumferential spacing are punched, the same layers of multiple iron core sub-bodies are automatically arranged in a ring, improving the neatness and efficiency of the arrangement. And the multiple iron core sub-bodies obtained by layer-by-layer stacking and riveting can be automatically and orderly press-riveted to the support with equal stacking height. Finally, a spoke-type rotor iron core with completely integral stacking and riveting connection is obtained. It can be seen that its manufacturing is simple, which is conducive to simplifying the processing procedures, facilitating high-frequency uninterrupted continuous and efficient operation, and improving the manufacturing efficiency. It overcomes the deficiency of inefficiently stacking and riveting each iron core sub-body in a single form, and after the processed iron core sub-bodies are completed, there is no need to arrange them in a ring on the support one by one afterwards, and the form of using tooling fixtures to position multiple iron core sub-bodies is eliminated.

[0017] Both the support and the iron core body are made of the same punching material, which can simplify the processing link, save the unit time cost of the spoke-type rotor iron core, and improve the processing efficiency.

[0018] The support can play a role in shielding one end of the permanent magnet. When the permanent magnet is fixed, one end cover can be saved at this end, or the axial limit structure can be saved in the corresponding position of the iron core body.

Description of the Drawings

[0019] Figure 1 is the plan view of the support piece of the spoke-type rotor iron core;

[0020] Figure 2 is the three-dimensional view of the support of the spoke-type rotor iron core;

[0021] Figure 3 is the three-dimensional view of the sector-shaped iron core piece, where the back is visible;

[0022] Figure 4 is the three-dimensional view of the sector-shaped iron core piece with the front visible;

[0023] Figure 5 is the three-dimensional view of a layer of sector-shaped iron core pieces (circumferentially spaced) riveted on the support;

[0024] Figure 6 is the three-dimensional view of the spoke-type rotor iron core manufactured by the method of the present invention;

[0025] Figure 7 is the schematic diagram of the spoke-type rotor iron core, (a) is the front view, (b) is the top view, and (c) is the bottom view.

Detailed Embodiment

[0026] Please refer to Figures 1 to 7As shown in the figure, the manufacturing method of the spoke-type rotor core will be described below by taking the example that 6 support pieces 1a are required to form a support 1 according to the process design requirements, and 10 iron core sub-bodies 3 are used to form an iron core body. Among them, each iron core sub-body 3 is composed of 48 sector-shaped iron core sheets 3b. The sheet thickness of both the sector-shaped iron core sheets 3b and the support pieces 1a is 0.5 mm per sheet. The designed stacking height of the support 1 is 3 mm, and the designed stacking height of each iron core sub-body 3 is 24 mm.

[0027] A manufacturing method of a spoke-type rotor core, which is used for an inner-rotor type permanent magnet motor and is processed on a continuously pushed electrical steel strip, successively includes the following steps:

[0028] a) Self-riveting support 1

[0029] Continuously stamp out 6 support pieces 1a ( Figure 1 ), and the support pieces are stacked and self-riveted to obtain the support 1 ( Figure 2 ). Among them, the support pieces are in an annular shape, and each support piece is punched with a first central hole 10a and rivet perforations 100a that are circumferentially spaced around the first central hole. Based on the first central hole of the support piece 1a, a first central shaft hole 10 of the support 1 is formed, and based on the rivet perforations 100a of the support piece, an axial through hole 100 of the support 1 with coaxiality is formed.

[0030] b) Stacking and riveting the iron core body onto the support 1

[0031] Continue to continuously punch out 10 permanent magnet slot holes 2b that are evenly distributed at circumferential intervals, and obtain 10 iron core sub-bodies 3 that are formed by stacking and self-riveting 48 layers of sector-shaped iron core sheets 3b in an annular arrangement. The 10 iron core sub-bodies 3 in the annular arrangement are stacked and riveted to the support 1 in an evenly ordered manner at circumferential intervals. Among them, the 10 sector-shaped iron core sheets 3b in each layer enclose a second central hole (not marked), and rivet perforations 300b are punched at circumferential intervals around the second central hole on the 10 sector-shaped iron core sheets 3b in each layer. The bottom of each permanent magnet slot 2 facing the support 1 between adjacent iron core sub-bodies 3 is closed by the support.

[0032] c) Blanking from the progressive stamping die to obtain a completely integrally stacked and riveted formed spoke-type rotor core.

[0033] Figure 5As shown, the process of punching 10 permanent magnet slots 2b in each layer is accompanied by simultaneously obtaining 10 sector-shaped iron core chips 3b with automatic circumferential interval sorting. Among them, the 10 sector-shaped iron core chips 3b at the bottom layer are directly press-riveted to the support piece 1a at the top layer of the support 1, and then 10 sector-shaped iron core chips in each layer are stacked and riveted to the corresponding sector-shaped iron core chips in the lower layer one by one until a core body composed of 10 core sub-bodies 3 is stacked on the support piece 1a after reaching the specified stacking height, and finally formed into a spoke-type rotor core( Figure 6 ).

[0034] As a preferred implementation mode, the support 1 in step a) and the core body in step b) are processed on a progressive die.

[0035] The electrical steel strip is conveyed by the conveying device of a known high-speed press; stamping includes, but is not limited to, blanking, punching, press-riveting or stacking and riveting, etc.; the progressive die is installed on the high-speed press.

[0036] As a preferred implementation mode, in step a), small through holes 110a for filling resin are also punched at circumferentially spaced positions near the first central hole 10a of each support piece 1a. Based on the small through holes 110a of each support piece 1a, small axial through holes 110 at corresponding positions of the support 1 are formed. The small axial through holes are all located within the circumference of the second central axis hole 30 surrounded by 10 core sub-bodies 3. The second central axis hole and the first central axis hole 10 are combined to form a stepped through hole.

[0037] Epoxy resin is used for the resin; as shown, the small axial through holes 110 are arranged along the step 11 of the stepped through hole.

[0038] As a preferred implementation mode, both the inner ends and outer ends of each permanent magnet slot hole 2b (that is, each permanent magnet slot 2) in step b) are open or the inner end is open.

[0039] The permanent magnet slots 2 are for inserting permanent magnets (not shown). The support 1 is not for inserting permanent magnets, that is, the permanent magnets inserted into the permanent magnet slots 2 are not inserted into the support 1. The support is an auxiliary part of the spoke-type rotor core, which serves as a platform for arranging, supporting and fixedly connecting 10 core sub-bodies 3, and plays a role in blocking one end face of the permanent magnet. Therefore, an end cover (not shown) can be saved for the permanent magnet; the stepped through hole formed by the combination of the first central axis hole 10 of the support 1 and the second central axis hole 30 non-closedly surrounded by 10 core sub-bodies 3 is for the support and axial positioning of the rotor shaft, combined with Figure 6 .

[0040] The diameter of the outer circle surrounded by 10 core sub-bodies 3 is equal to or less than the outer circle diameter of the support 1. Specifically, in implementation, the outer diameter of the support 1, that is, the support piece 1a, is 96.8 mm, and the outer diameter of the core body is 96.0 mm or 96.8 mm.

[0041] Please refer to Figure 6 , the end cover (not shown) can be riveted to the upper end surface of the iron core body 3 through rivets (not shown), that is, covering the opening of the permanent magnet slot 2.

[0042] Based on the rivet perforations 300b of the sector iron core sheets 3b, each iron core body 3 forms an axially through hole 300 with coaxiality; based on the permanent magnet slot holes 2b between adjacent sector iron core sheets 3b, a permanent magnet slot 2 with coaxiality is formed; based on the second central holes (not labeled) surrounded by 10 sector iron core sheets 3b in each layer, the iron core body forms a second central axis hole 30.

Claims

1. A manufacturing method of a spoke-type rotor core, which is used for an inner-rotor permanent magnet motor and is processed on a continuously pushed electrical steel strip, characterized in that it successively includes the following steps: a) Self-riveting support, continuously stamping a plurality of support pieces, and the support pieces are laminated and self-locked and riveted to obtain a support. Among them, the support pieces are annular, and each support piece is punched with a first central hole and rivet perforations are punched at intervals along the circumference around the first central hole. The support forms a first central shaft hole based on the first central hole and an axial through hole based on the rivet perforations; b) Stacking and riveting the core body on the support, continuously punching out a plurality of permanent magnet slot holes evenly distributed at circumferential intervals layer by layer to obtain a plurality of core sub-bodies formed by self-locking and riveting of multiple layers of fan-shaped iron core sheets arranged in a ring. The plurality of core sub-bodies are stacked and riveted to the support evenly and orderly at circumferential intervals. Among them, a plurality of fan-shaped iron core sheets in each layer enclose a second central hole, and rivet perforations are punched at intervals along the circumference on the plurality of fan-shaped iron core sheets in each layer around the second central hole. The bottom of each permanent magnet slot facing the support between adjacent core sub-bodies is closed by the support; c) Blanking from the progressive die to obtain a completely integrally stacked and riveted and formed spoke-type rotor core.

2. The manufacturing method of the spoke-type rotor core according to claim 1, characterized in that: the base in step a) and the core body in step b) are processed on a progressive die.

3. The manufacturing method of the spoke-type rotor core according to claim 1 or 2, characterized in that: in step a), small through holes for filling resin are punched at circumferential intervals near the first central hole of each support piece, and small axial through holes are formed on the support based on the small through holes. The small axial through holes are all located within the circumference of the second central shaft hole surrounded by a plurality of core sub-bodies, and the second central shaft hole and the first central shaft hole are combined into a stepped through hole.

4. The manufacturing method of the spoke-type rotor core according to claim 1, characterized in that: both the inner and outer ends of each permanent magnet slot hole in step b) are open or the inner end is open.

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