Motor rotor and manufacturing method thereof

Abstract

To solve the problem in a conventional motor rotor having a structure of fixing a permanent magnet with caulking, in which a brittle material such as an amorphous material is hardly applied to a core plate.SOLUTION: A motor rotor 1 comprises: a core material 2 that is formed by laminating a plurality of core plates 2, and includes a penetration hole 3 penetrating in its lamination direction; and a permanent magnet 5 that is housed in the penetration hole 3. The permanent magnet 5 includes a concave part 6 which is opened to a side surface in at least a rotor shaft rotating direction R, Some core plates 2 of the plurality of core plates 2 are engaged with the concave part 6 in a state of being deviated in the rotor shaft rotational direction. Even if a thin plate such as an amorphous material is used for the core plate 2, the permanent magnet 5 can be sufficiently fixed, and the structure can contribute to improve a performance of a motor.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an improvement in a motor rotor that constitutes a motor. [Background technology]

[0002] An example of a conventional motor rotor is described in Patent Document 1. The motor core described in Patent Document 1 is formed by stacking multiple core plates and has a through hole for accommodating a permanent magnet. Inside the through hole, a fixed piece and a recess are formed in a selected core plate. The motor core accommodates a permanent magnet in the through hole, and the fixed piece is bent into the recess and pressed against the permanent magnet, thereby fixing the permanent magnet in the through hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-172441 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in order to improve motor performance, the use of thin plates such as amorphous materials for the core plates of motor rotors has been considered. However, conventional motor rotors have a structure in which a fixed piece is bent and pressed against a permanent magnet, that is, a structure in which the permanent magnet is fixed by so-called caulking, and this poses the problem that it is difficult to use brittle materials such as amorphous materials for the core plates, and solving this problem has been an issue.

[0005] The present invention has been made in consideration of the above-mentioned problems in the conventional technology, and aims to provide a motor rotor and a manufacturing method thereof that can sufficiently fix permanent magnets even when a thin plate of amorphous material or the like is used for the core plate, thereby contributing to improved motor performance. [Means for solving the problem]

[0006] The motor rotor according to the present invention comprises a core material formed by stacking a number of core plates and having a through hole penetrating in the stacking direction, and a permanent magnet housed in the through hole. In the motor rotor, the permanent magnet has a recess on the side that is open at least in the direction around the rotor axis, and some of the core plates are engaged with the recess. The engagement points between the core plate and the recesses are provided on the rotor shaft side of the permanent magnet and at positions symmetrical with respect to the center line of the permanent magnet which coincides with the radial direction of the core material. It is characterized by the fact that

[0007] The manufacturing method of the motor rotor according to the present invention is characterized in that, when manufacturing the above-mentioned motor rotor, a through hole and a through hole that is open in the stacking direction of the core plates are formed in the core material, a permanent magnet is placed in the through hole of the core material, and then a jig is inserted into the through hole to press some of the multiple core plates in the direction around the rotor axis to engage them with the recesses. Effect of the Invention

[0008] The motor rotor and the manufacturing method thereof according to the present invention employ the above-mentioned configuration, so that the permanent magnets can be sufficiently fixed even when a thin plate of an amorphous material or the like is used for the core plate. At the same time, damage to the permanent magnets 5 due to centrifugal force can be suppressed. This can contribute to improving the performance of the motor. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view illustrating a quarter portion of a first embodiment of a motor rotor according to the present invention. [Diagram 2] 2A is a perspective view illustrating the permanent magnet shown in FIG. 1, and FIG. 2B is a perspective view showing another example of a recess of the permanent magnet. [Diagram 3] 2 is a cross-sectional view of a main part taken along the line AA in FIG. 1, in which (A) is a cross-sectional view showing a state in which a permanent magnet is accommodated, and (B) is a cross-sectional view showing a state in which the permanent magnet is fixed. [Figure 4] 3A to 3D are plan views illustrating a core plate applicable to the first embodiment. [Diagram 5] 5A is a cross-sectional view showing a state in which a permanent magnet is accommodated, and FIG. 5B is a cross-sectional view showing a state in which the permanent magnet is fixed, illustrating a second embodiment of a motor rotor according to the present invention. FIG. [Figure 6] 13A to 13F are plan views illustrating a core plate applicable to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First Embodiment The motor rotor 1 shown in Fig. 1 constitutes a motor together with a stator (not shown) arranged on the outer periphery, and rotates about a rotor shaft Cr. The motor rotor 1 includes a core material 4 formed by stacking a plurality of core plates 2 and having a through hole 3 penetrating in the stacking direction, and a permanent magnet 5 accommodated in the through hole 3.

[0011] 2(A), the permanent magnet 5 has a recess 6 on its side that is open at least in the direction around the rotor shaft (direction of arrow R). The motor rotor 1 has a structure in which some of the core plates 2 among the multiple core plates 2 are engaged with the recess 6. In this embodiment, some of the core plates 2 are engaged with the recess 6 while being shifted in the direction around the rotor shaft (direction of arrow R).

[0012] The core material 4 has through holes 3 at regular intervals along its periphery, and also has a plurality of through holes 7 that are open in the lamination direction of the core plates 2. The permanent magnet 5 in the illustrated example is a rectangular flat plate, and is housed in the through hole 3 with the long side of its main surface aligned with the lamination direction of the core plates 2. The core material 4 is laminated with other core materials as necessary to form a laminate, and end plates and a rotating shaft are attached above and below the laminate.

[0013] The permanent magnet 5 has a plurality of recesses 6 (three in the illustrated example) formed at a predetermined interval at the corner between the main surface on the rotor shaft Cr side and one of the two side surfaces when placed in the through hole 3. As a result, the recesses 6 are open at least in the direction around the rotor shaft, and are also open to the rotor shaft Cr side.

[0014] Next, the rotor motor 1 and a manufacturing method thereof will be described with reference to FIG. That is, in the manufacturing method of the rotor motor 1, as shown in Fig. 3(A), a plurality of core plates 2 are stacked, and then permanent magnets 5 are housed in the through holes 3. Next, in the manufacturing method, some of the plurality of core plates 2, more specifically, the core plates 2 at positions corresponding to the respective recesses 6 of the permanent magnets 5, are shifted in the direction around the rotor axis as shown in Fig. 2(B).

[0015] At this time, in the above manufacturing method, a jig 8 is used which is inserted into the through hole 7 near the through hole 3. As shown in Fig. 2(B), this jig 8 has a body 8A with protrusions 8B which correspond to the positions of each recess 6. After being inserted into the through hole 3, each protrusion 8B presses the corresponding core plate 2 and moves it around the rotor shaft. This causes a part of the core plate 2 to engage with each recess 6.

[0016] In this way, in the motor rotor 1 and its manufacturing method described above, the permanent magnets 5 are fixed in the through holes 3 in the core material 4. For ease of understanding, the drawings show a state in which one core plate 2 is engaged with each recess 6. However, when a thin plate made of an amorphous material is used for the core plate 2, it is not easy to engage one core plate 2 with one recess 6 because the plate thickness is about 0.1 mm. In such a case, each of the illustrated core plates 2 can be replaced with a core plate group (2) made up of many core plates 2, and the core plate group (2) is engaged with each recess 6 to fix the permanent magnets 5.

[0017] The above-described motor rotor 1 and its manufacturing method can fix the permanent magnets 5 without bending the core plate 2, as opposed to the conventional method of fixing the permanent magnets by crimping the core plate. Therefore, even if a thin plate made of a brittle material such as an amorphous material is used for the core plate, the permanent magnets 5 can be sufficiently fixed, which contributes to improving the performance of the motor.

[0018] Furthermore, in the above-described motor rotor 1 and its manufacturing method, the core plate (core plate group) 2 and the permanent magnets 5 are structured to interlock with each other, so that the permanent magnets 5 can be fixed more firmly than with a structure that maintains a fixed state by frictional force, such as with crimping, and the laminated portions between adjacent recesses 6 can be sufficiently fixed.

[0019] Furthermore, in the conventional structure in which the permanent magnet is fixed by crimping the core plate, a space is required inside the through hole to accommodate the deformed portion of the core plate. In contrast, in the above-mentioned motor rotor 1 and its manufacturing method, when the core plate 2 is moved around the rotor axis, as shown in Fig. 1(B), a gap S is generated between the moved core plate 2 and the permanent magnet 5, but this gap S is extremely small, about the depth of the recess 6.

[0020] In the above motor rotor 1 and its manufacturing method, the position, number, and shape of the recesses 6 of the permanent magnet 5 are not limited to those in the above embodiment, and it is also possible to adopt, for example, either or both of the recesses 6A and 6B shown in Fig. 2(B). The recess 6A shown on the upper side in Fig. 2(B) is a groove formed along the plate thickness direction of the permanent magnet 5, and is entirely open in the direction around the rotor shaft. The recess 6B shown on the lower side in Fig. 2(B) is a groove formed within a certain range in the direction around the rotor shaft from the end on the surface of the permanent magnet 5 on the rotor shaft Cr side, and is open in the direction around the rotor shaft at the end.

[0021] In the above-described motor rotor 1 and manufacturing method thereof, the shape of the core plate 2 that engages with the recess 6 formed in the permanent magnet 5 can be appropriately selected depending on the shape of the recess 6. For example, two types of core plates 2A and 2B as shown in Figs. 4(A) and (B) can be used for the motor rotor 1 of this embodiment.

[0022] The first core plate 2A shown in Fig. 4(A) corresponds to parts other than the recessed part 6, has an opening H for forming the through hole 3, and is immovable when engaged with the permanent magnet 5. The second core plate 2B shown in Fig. 4(B) corresponds to the recessed part 6 of the permanent magnet 5, and also has an opening H, and has a protrusion 2P on the edge of the opening H that becomes an engaging part with the recessed part 6, and moves when engaged with the permanent magnet 5. The openings H communicate with each other to form the through hole 3 when the core plates 2A, 2B are stacked.

[0023] When the core plates 2A, 2B are stacked on top of each other, the second core plate 2B is pre-displaced so that the permanent magnet 5 and the protruding piece 2P do not interfere with each other in the through-hole 3, as shown in Fig. 4(C). After the permanent magnet 5 is accommodated in the through-hole 3, the second core plate 2B is moved in the direction opposite to the initial displacement direction, so that the protruding piece 2P of the second core plate 2B engages with the recess 6 of the permanent magnet 5, and the permanent magnet 55 is fixed in the through-hole 3. As a result, the entire openings H of all the core plates 2A, 2B of the motor rotor 1 are aligned, realizing a structure without gaps S as shown in Fig. 3(B).

[0024] Second Embodiment 5 and 6 are diagrams illustrating a motor rotor according to a second embodiment of the present invention. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0025] In the motor rotor 1 shown in Fig. 5(A), the permanent magnet 5 has multiple recesses 6 arranged in the lamination direction of the core plate 2. The permanent magnet 5 in the illustrated example has multiple recesses 6 at the corner (the left corner in the figure) between the main surface on the rotor shaft Cr side and one side surface, and multiple recesses 6 at the corner (the right corner in the figure) between the main surface and the other side surface. The recesses 6 on both side surfaces are provided at different positions in the lamination direction of the core plate 2, although the number of each is not limited.

[0026] 5(B), some of the core plates 2 of the motor rotor 1 are engaged with each of the recesses 6 from one direction around the rotor shaft (the direction of arrow R1). Also, other some of the core plates 2 of the motor rotor 1 are engaged with other of the recesses 6 from the other direction around the rotor shaft (the direction of arrow R2).

[0027] The motor rotor 1 of this embodiment can use three types of core plates 2A, 2B, and 2C as shown in Figures 6(A) to 6(C). The first core plate 2A shown in Figure 6(A) corresponds to parts other than the recessed parts 6, has an opening H for forming the through hole 3, and is immobile when engaged with the permanent magnet 5.

[0028] The second core plate 2B shown in Fig. 6(B) corresponds to the recess 6 on one side of the permanent magnet 5, and similarly has an opening H, and has a protrusion 2P on the edge of the opening H that serves as an engaging portion with the recess 6. The third core plate 2C shown in Fig. 6(C) corresponds to the recess 6 on the other side of the permanent magnet 5, and similarly has an opening H, and has a protrusion 2Q on the edge of the opening H, at a position symmetrical to the protrusion P of the second core plate 2B, that serves as an engaging portion with the recess 6. The openings H communicate with each other to form through holes 3 when the core plates 2A to 2C are stacked.

[0029] When the above core plates 2A to 2C are stacked on top of each other, the second and third core plates 2B, 2C are shifted in advance in opposite directions to each other so that the permanent magnet 5 and the protrusions 2P, 2Q do not interfere with each other within the through hole 3, as shown in Figure 6 (D).

[0030] Then, after the permanent magnet 5 is accommodated in the through hole 3, the second core plate 2B is moved in the direction opposite to the initial displacement direction (the direction of arrow R1) as shown in Figure 6 (E), and the protrusion 2P of the second core plate 2B is engaged with the recess 6 on one side of the permanent magnet 5.

[0031] 6(F), the third core plate 2C is moved in the opposite direction to the initial displacement (the direction of arrow R2) to engage the protruding piece 2P of the second core plate 2B with the recess 6 on the other side of the permanent magnet 5. This causes the motor rotor 1 to fix the permanent magnet 5 in the through hole 3. The second and third core plates 2B and 2C can also be moved simultaneously.

[0032] In this way, the above-mentioned motor rotor 1 can adequately fix the permanent magnets 5 even when a thin plate made of a brittle material such as an amorphous material is used for the core plate 2, as in the first embodiment. In particular, by constraining the permanent magnets 5 on both sides, the fixing force can be further increased, which can contribute to improved motor performance.

[0033] Moreover, the above motor rotor 1 is configured such that the engagement points between the core plate 2 and the recesses 6 are provided on the rotor shaft side of the permanent magnet 5 and at positions symmetrical with respect to the center line Cm of the permanent magnet 5 which coincides with the radial direction of the core material 4. In short, the above motor rotor 1 is configured such that the engagement points between the core plate 2 and the recesses 6 are disposed at both ends of the permanent magnet 5 on the rotor shaft side.

[0034] The motor rotor 1 described above has improved durability against the centrifugal force generated at the center of gravity of the permanent magnet 5 due to rotation. That is, when the motor rotor 1 rotates, as shown in Fig. 6(F), a centrifugal force F1 is generated at the center of gravity of the permanent magnet 5, and the permanent magnet 5 receives a reaction force F2 from the core material 4. At this time, the permanent magnet 5 may be damaged if a bending moment or a non-uniform, locally excessive load occurs.

[0035] Therefore, the motor rotor 1 has a structure in which the restraining portion of the core material 4 for the permanent magnet 5 is one surface, multiple surfaces, or a point that is symmetrical with respect to the direction of the centrifugal force F1 (center line Cm). As a result, the motor rotor 1 restrains the permanent magnet 5 at a portion that is symmetrical with respect to the center of gravity of the permanent magnet 5, thereby suppressing damage to the permanent magnet 5 due to centrifugal force and improving durability. Furthermore, improving the durability of the permanent magnet 5 can contribute to improving the maximum rotation speed of the motor, which also makes it possible to reduce the size of the motor.

[0036] The configuration of the motor rotor according to the present invention is not limited to the above-mentioned embodiments, and can be modified as appropriate without departing from the scope of the present invention. The motor rotor described above can also be applied to a generator rotor that has substantially the same configuration as a motor. [Explanation of symbols]

[0037] 1 Motor rotor 2 Core plate 2 A~2C Core plate 3. Through hole 4 Core material 5. Permanent magnets 6 Recess 7 Through hole 8 Jig

Claims

1. A core material formed by laminating a plurality of core plates and having a through hole passing through in the lamination direction; A motor rotor having a permanent magnet housed in the through hole, the permanent magnet has a recess on a side surface thereof that is open at least in a direction around the rotor axis, Some of the core plates are engaged with the recesses, A motor rotor characterized in that the engagement point between the core plate and the recess is located on the rotor shaft side of the permanent magnet and in a position symmetrical with respect to the center line of the permanent magnet which coincides with the radial direction of the core material.

2. the permanent magnet has a plurality of recesses arranged in a lamination direction of the core plate, Some of the core plates are engaged with the recesses from one direction around the rotor shaft, 2. The motor rotor according to claim 1, wherein another part of the plurality of core plates engages with another of the recesses from another direction around the rotor axis.

3. When manufacturing the motor rotor according to claim 1, the core material has the through hole and a through hole that is open in the lamination direction of the core plate, After the permanent magnet is accommodated in the through hole of the core material, A method for manufacturing a motor rotor, comprising the steps of: pressing some of the plurality of core plates in a direction around the rotor axis using a jig inserted into the through hole to engage with the recess;

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