Motor rotor

Abstract

To provide a motor rotor that can fix a permanent magnet regardless of the material or the shape of a core plate to be an iron core.SOLUTION: A motor rotor of the present invention comprises: a core material obtained by laminating a plurality of core plates each having an insulating coating on both front and rear faces; and permanent magnets provided in a through hole penetrating in a lamination direction of the core plates. The motor rotor has a plate member that covers one face of the core material, and a guide member having a plane part that covers the other face of the core material and a connection part that extends from the plane part, passes through a lateral side of the permanent magnet, and reaches the one face in the through hole. At least one of the plate member and the plane part of the guide member has a spring part at a position in contact with the permanent magnet in the through hole. The connection part of the guide member and the plate member are joined to each other; and the spring part presses the permanent magnet in the lamination direction; and thereby the permanent magnet can be fixed regardless of the material or the shape of the core plate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a motor rotor, and more particularly to an embedded magnet type motor rotor. [Background technology]

[0002] Interior permanent magnet (IPM) motors, in which permanent magnets are embedded inside the rotor, can actively utilize the rotational force (reluctance torque) generated by changes in magnetic energy relative to the position, and are used in electric vehicles because they are highly efficient and can be operated over a wide range of speeds.

[0003] Patent Document 1 describes a motor core in which steel plates are laminated, permanent magnets are housed in holes formed in the steel plates, and the permanent magnets are fixed by pressure welding with fixing pieces provided on the inner edges of the holes in the steel plates. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-172441 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the motor core described in Patent Document 1, the permanent magnets are fixed by the elasticity of the steel plates themselves, so it is not possible to use thin steel plates with weak elasticity or brittle iron-based amorphous metal plates. In addition, it is difficult to provide a flux barrier near the permanent magnet, which limits the shape of the steel plates, limiting the freedom in designing the magnetic circuit.

[0006] The present invention has been made in consideration of the problems associated with the conventional technology, and its object is to provide a motor rotor in which a permanent magnet can be fixed regardless of the material or shape of the core plate that serves as the core material. [Means for solving the problem]

[0007] As a result of extensive research into achieving the above-mentioned objective, the inventors discovered that the above-mentioned objective could be achieved by clamping a core material and a permanent magnet on both sides in the stacking direction and pressing the permanent magnet in the stacking direction using a fixing member having a spring at the portion that abuts the permanent magnet, and thus completed the present invention.

[0008] That is, the motor rotor of the present invention is The magnet comprises a core material in which a plurality of core plates having insulating coatings on both sides are laminated and which has a through hole penetrating in the lamination direction, and a permanent magnet housed in the through hole. do. and, the core material and the permanent magnet are each divided in the stacking direction by a plate member, the plate member covers one surface of the core material and has a spring portion located at a position where it abuts against the permanent magnet, and two through holes corresponding to the through holes and located on the sides of the permanent magnet, Furthermore, the magnet further includes a ring-shaped band that passes through the two through holes of the plate member and both sides of the permanent magnet in the through hole, surrounds the entirety of the divided permanent magnet, and restrains the plate members at both ends in the stacking direction, and has a portion that is offset in the circumferential direction between the core material that houses the adjacent permanent magnet and the plate member, the ring-shaped band forming a rectangle at the offset portion, and the spring portion presses the permanent magnet in the stacking direction. .

[0009] A method for producing a motor rotor according to the present invention is a method for producing the above motor rotor. and, a step of alternately stacking the core material having the permanent magnets housed in the through holes and the plate members, and bringing the spring portions of the plate members into contact with the permanent magnets; a step of passing the strip through a through hole of the core material and a through hole of the plate member so that the strip passes through an interior of a laminate in which the core material and the plate member are alternately laminated, forming a U-shape; a step of pressing the plate member to elastically deform the spring portion; a step of maintaining the spring portion in an elastically deformed state, shifting a portion of the core material and the plate member together in a circumferential direction, and drawing the strip into the inside of the laminate to form a rectangular strip between the core material and the plate member; and maintaining the spring portion in an elastically deformed state, and bending and joining the portion of the band plate protruding from the plate member to form the band plate into a ring shape. . Effect of the Invention

[0010] According to the present invention, the core material and the permanent magnet are sandwiched from both sides in the stacking direction, and the permanent magnet is pressed and fixed in place in the stacking direction, thereby providing a motor rotor with high freedom in designing the magnetic circuit and enabling high efficiency. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a quarter-shaped plan view showing an example of a motor rotor. [Diagram 2] 2 is a cross-sectional view of the first embodiment taken along the line AA' in FIG. [Diagram 3] 10A and 10B are diagrams illustrating a state in which a core material and a permanent magnet are installed on a guide member. [Figure 4]13 is a diagram illustrating a state in which a plate member is set on a guide member on which a core material and a permanent magnet are disposed. FIG. [Diagram 5] 13A and 13B are diagrams illustrating a state in which a compressive load is applied to the plate member to cause the spring portion to elastically deform. [Figure 6] FIG. [Figure 7] 2 is a cross-sectional view of the second embodiment taken along the line AA' in FIG. [Figure 8] 11A to 11C are diagrams illustrating an assembly procedure of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The motor rotor of the present invention will now be described in detail. The motor rotor includes a core material formed by laminating a plurality of core plates having insulating coatings on both sides, and a permanent magnet provided in a through hole that passes through the core material in the lamination direction.

[0013] The core plate is made of an electromagnetic steel plate or an iron-based amorphous metal plate with an insulating coating formed on both sides thereof, and has a circular shape.

[0014] A quarter-section plan view of the motor rotor is shown in Figure 1. In this figure, the surface plate members have been omitted so that the permanent magnets installed in the core material and the positions of the flux barriers can be seen.

[0015] As shown in Figure 1, a circular core plate has a central hole through which the shaft passes, and around it are holes to accommodate permanent magnets and holes to act as flux barriers in a specific pattern. These holes can be formed by punching out the core plate.

[0016] The core material is made by stacking multiple core plates so that the positions of the through holes are aligned, and a permanent magnet is housed in at least one of the through holes that penetrates in the stacking direction, while the through holes that do not house a permanent magnet function as a flux barrier that obstructs magnetic flux.

[0017] The thickness of the core plate is preferably 0.01 to 0.3 mm. A thin core plate can reduce iron loss caused by the generation of eddy currents.

[0018] (First embodiment) A method for fixing the core material and the permanent magnet will be described. FIG. 2 shows a cross-sectional view taken along line AA' in FIG.

[0019] In the present invention, a fixing member is used that has a planar portion covering one side of the core material and permanent magnet, a planar portion covering the other side, and a connecting portion that passes along the side of the permanent magnet inside the through hole and connects the two planar portions.

[0020] As shown in Figure 2, this fixing member has a spring portion on at least one of the planar portions on one side and the other side at a position where it abuts the permanent magnet, and fixes the permanent magnet by pressing the permanent magnet in the stacking direction and pressing the permanent magnet against one surface side and / or the other surface side.

[0021] The fixing member can be made of a material having sufficient rigidity to not be deformed by the reaction force from the permanent magnet in the spring portion, and metal, resin, or the like can be used.

[0022] Furthermore, at least the portion of the fixing member that passes through the through hole of the core material has insulating properties. Since the core plate is punched and formed as described above, the insulating coating is discontinued at the cross section. However, by making the portion of the fixing member that passes through the through hole insulating, it is possible to prevent adjacent core plates from becoming electrically connected to each other through the fixing member.

[0023] The portion passing through the through hole does not need to have insulating properties all the way to the inside, and may be made of a metal having an insulating coating on its surface.

[0024] The procedure for assembling a motor rotor using this fixing member will be described using an example in which a metal plate member and a resin guide member are used.

[0025] The guide member has a flat portion and a plurality of connection portions erected on the flat portion, as shown in Fig. 3. The connection portions of the guide member pass through the through holes of the core material, and the core material is placed on the flat portion so that the tips of the connection portions are higher than the height of the core material. A permanent magnet is also placed in the through holes between the connection portions of the guide member.

[0026] Next, as shown in FIG. 4, a plate member having a spring portion is set so as to cover the permanent magnet and the core material and so that the spring portion abuts against the permanent magnet inside the through hole.

[0027] The plate member has a through hole at a position corresponding to the connecting portion of the guide member, and the tip of the connecting portion can be inserted into this through hole to enable positioning.

[0028] The through holes and spring portions of the plate member can be formed, for example, by a convex shape provided on a die during press working.

[0029] Then, a compressive load is applied to the plate member covering the permanent magnet and the core material, causing the spring portion in contact with the permanent magnet to elastically deform, as shown in Fig. 5. While maintaining this state, the tip of the connection portion of the guide member protruding from the through hole of the plate member is crimped as shown in Fig. 6 to join the guide member and the plate member.

[0030] This joining maintains the state in which the permanent magnets are pressed in the stacking direction, and the permanent magnets are pressed against the guide member, making it possible to fix the permanent magnets in place.

[0031] In the motor rotor of the present invention, the core plate itself does not need to have rigidity, so a thin core plate or an iron-based amorphous metal plate can be used, and a flux barrier can be provided in the vicinity of the permanent magnet, thereby improving the design freedom of the magnetic circuit.

[0032] Furthermore, since the core material is held by the guide members during assembly, the members and operations required for maintaining the laminated state of the core material can be omitted, and the manufacturing process can be simplified.

[0033] Second embodiment In a motor that utilizes reluctance torque, if the flux barrier changes are synchronized, rotation unevenness occurs when the motor is under load. In the motor rotor of the second embodiment, the position of the flux barrier is shifted in the lamination direction of the core plate, thereby reducing the occurrence of the above-mentioned rotation unevenness.

[0034] FIG. 8 shows a cross-sectional view taken along the line AA' in FIG. 1 when core members housing permanent magnets and plate members are alternately laminated.

[0035] The motor rotor of the second embodiment is a motor rotor in which a core material and a permanent magnet housed in its through hole are divided in the stacking direction by plate members, and as shown in Figure 8, the core materials housing the permanent magnets and the plate members are stacked alternately, with some portions being circumferentially offset between adjacent core materials and plate members.

[0036] The plate member has a spring portion located at a location where it abuts against the permanent magnet, and two through holes that correspond to the through holes and are located on the sides of the permanent magnet.

[0037] In the second embodiment, a ring-shaped band plate is used instead of the guide member. As shown in Figure 7, this annular band passes through the two through holes in the plate member and both sides of the permanent magnet in the hole, penetrating the inside of the motor rotor and surrounding the entire divided permanent magnet, restraining the entire motor rotor via the plate members at both ends in the stacking direction.

[0038] The procedure for assembling a motor rotor using this ring-shaped strip will now be described. First, core members having permanent magnets housed in their through-holes and plate members are alternately laminated. At this time, as shown on the left side of FIG. 8, all the plate members are aligned so that their two through holes are aligned in a straight line and positioned to the side of the permanent magnets in the through holes.

[0039] Then, the strip is passed through one of the through holes in the plate member at one end and through the through holes and transparent holes arranged in a straight line in the stack, folded back at the plate member at the other end, and passed through the inside of the stack in the same manner from the other through hole in the plate member at the other end so that the strip becomes U-shaped.

[0040] Next, as shown in the center of Figure 8, the plate member shown on the left is pushed in the stacking direction to compress the entire stack of core materials and plate members, elastically deforming the spring portion, and while this spring portion is maintained in its elastically deformed compressed state, some of the core materials and plate members are shifted together in the circumferential direction.

[0041] Then, as shown on the right side of Figure 8, the strip is pulled into the interior of the laminate, forming a rectangle between the core material and the plate member, and the part that has deformed into this rectangle abuts against the plate member or the permanent magnet.

[0042] Finally, the portion of the band plate protruding from the plate member on one end side is folded and the open portions of the U-shaped band plate are joined together to form a ring shape.

[0043] The rectangular portion of the annular band formed inside this laminate and the plate members at both ends in the stacking direction press the permanent magnet against the rectangular portion of the annular band or the plate members against the reaction force of the spring portion abutting the permanent magnet, thereby fixing the permanent magnet.

[0044] In the second embodiment, the centrifugal force generated in the permanent magnet when the motor rotor rotates can be supported by the annular band, thereby improving strength; furthermore, the entire motor rotor is restrained by the annular band, thereby increasing torsional rigidity and improving quietness. Furthermore, since the laminates each having a permanent magnet housed in the through-hole can be fixed together, productivity is improved.

[0045] The motor rotor can also be used as a generator rotor. [Explanation of symbols]

[0046] 1 Core material 11 Core plate 12 Through hole 2. Permanent magnets 3 Guide member 31 Plane part 32 Connection 4 Plate members 41 Spring section 42 Through hole 5. Belt 6 Jig R motor rotor S stator

Claims

1. A core material comprising a plurality of laminated core plates each having an insulating coating on both sides and having a through hole passing through in the lamination direction; A permanent magnet is accommodated in the through hole, A motor rotor in which the core material and the permanent magnets are each divided in a lamination direction by a plate member, the plate member covers one surface of the core material and has a spring portion located at a position where it contacts the permanent magnet, and two through holes corresponding to the through holes and located on the sides of the permanent magnet; Further, a ring-shaped band plate is provided which passes through the two through holes of the plate member and both sides of the permanent magnet in the through hole, surrounds the entirety of the divided permanent magnet, and restrains the plate members at both ends in the stacking direction, The core member and the plate member are offset in the circumferential direction from each other. a first portion of the permanent magnet that is disposed in a first direction and a second portion of the permanent magnet that is disposed in a second direction;

2. A method for manufacturing the motor rotor according to claim 1, comprising the steps of: a step of alternately stacking the core material having the permanent magnets housed in the through holes and the plate members, and bringing the spring portions of the plate members into contact with the permanent magnets; a step of passing the strip through a through hole of the core material and a through hole of the plate member so that the strip passes through an interior of a laminate in which the core material and the plate member are alternately laminated, forming a U-shape; a step of pressing the plate member to elastically deform the spring portion; a step of maintaining the spring portion in an elastically deformed state, shifting a portion of the core material and the plate member together in a circumferential direction, and drawing the strip into the inside of the laminate to form a rectangular strip between the core material and the plate member; and maintaining the spring portion in an elastically deformed state, and bending and joining the portion of the band plate protruding from the plate member to form the band plate into a ring shape.

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