Interior magnet rotor and rotating electric machine

Abstract

According to an embodiment of the present invention, an interior permanent magnet rotor (100) has a rotor shaft, a rotor core (120), permanent magnets (130), and two end plates. The rotor core (120) has a plurality of electromagnetic steel sheets (120a) stacked in a rotational axis direction and includes two permanent magnet storage holes (121) arranged in a radially outer portion apart from each other in the circumferential direction in a V-shape across each d-axis. The end plates have a smaller outer diameter than that of the rotor core, are disposed at both ends of the electromagnetic steel sheets in the rotational axis direction and prevent the permanent magnets (130) from protruding in the rotational axis direction. The permanent magnet storage holes (121) communicate with the outside of the outer circumferential surface of the rotor core (120). The plurality of electromagnetic steel sheets in neighboring areas of the end plates in the rotational axis direction of the rotor core (120) have connection parts (125) for connecting the electromagnetic steel sheets to each other.

Description

[Technical field]

[0001] The present invention relates to an interior permanent magnet rotor and a rotating electric machine having the same. [Background technology]

[0002] The rotating electric machine includes a rotor having a rotor shaft and a rotor core, and a stator provided radially outside the rotor core.

[0003] The stator has a stator winding, which is a high-voltage part wound around stator teeth formed on the stator core. The stator winding has a part that penetrates the stator core and is housed in the stator slot, and coil end parts that protrude axially outward from both axial sides of the stator core and are connected to each other.

[0004] In an embedded magnet rotor, a through hole extending in the axial direction is formed in a region close to the radial outside of the rotor core, and a permanent magnet is housed in the through hole. The rotor core usually has multiple electromagnetic steel plates laminated in the axial direction. End plates are provided on both axial ends of the laminated electromagnetic steel plates to prevent the permanent magnets from protruding outward in the axial direction.

[0005] Since the end plate is located near the coil end of the high-voltage stator winding, it is necessary to secure an insulation distance, i.e., a distance from the stator end structure, from the viewpoint of electrical insulation. Therefore, it is preferable to make the diameter of the end plate as small as possible. For this reason, the diameter of the end plate is usually smaller than the diameter of the rotor core.

[0006] In many cases, a top bridge, which is part of the rotor core, is present between the through holes for storing the permanent magnets and the outer surface of the rotor core to ensure the structural strength of the rotor core. This top bridge serves as a passage for magnetic flux, i.e., a magnetic path. Magnetic flux passing through this magnetic path remains only within the rotor and becomes leakage flux that does not interlink with the stator side, resulting in reduced torque efficiency of the rotating electric machine. In light of this, there are examples of top-bridgeless rotors that remove the top bridge and connect the storage space for the permanent magnets to the outer space of the rotor core (the gap space between the rotor and stator) to reduce leakage flux. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 5447418 Summary of the Invention [Problem to be solved by the invention]

[0008] In the above-mentioned top bridgeless interior magnet rotor, the diameter of the end plates is also usually smaller than the diameter of the rotor core, i.e., the radially outer ends of the rotor core are radially outward from the radially outer ends of the end plates.

[0009] With this type of configuration, there was a problem in that the force resulting from the centrifugal force acting on the permanent magnets and the wind pressure caused by the rotation of the rotor could cause deformation of the portions of the electromagnetic steel sheet radially outward from the end plates, particularly in the areas near both axial ends of the rotor core, which could result in damage to the rotor.

[0010] An object of the present invention is to provide an interior permanent magnet type rotor and a rotating electric machine capable of preventing deformation of the ends of the electromagnetic steel plates that make up the rotor core. [Means for solving the problem]

[0011] In order to achieve the above object, an embedded magnet type rotor according to an embodiment of the present invention has a rotor shaft extending in a rotation axis direction, and a plurality of electromagnetic steel plates laminated in the rotation axis direction, and is attached to the radially outer side of the rotor shaft, the an embedded magnet type rotor having a rotor core in which two permanent magnet storage holes are formed in a radially outer portion, the two permanent magnet storage holes being spaced apart from each other in the circumferential direction and arranged in a convex manner radially inward on either side of a d-axis; plate-shaped permanent magnets stored in each of the permanent magnet storage holes; and two end plates having an outer diameter smaller than the outer diameter of the rotor core and arranged at both ends of a plurality of the electromagnetic steel sheets in the rotational axis direction to prevent the permanent magnets from protruding outward in the rotational axis direction, wherein the permanent magnet storage holes communicate with the outside of an outer peripheral surface of the rotor core, and the plurality of the electromagnetic steel sheets in a region near the end plates in the rotational axis direction of the rotor core are A number of electromagnetic steel sheets are used to prevent deformation caused by wind pressure generated by rotation. Connect with each other Conclusion The joining portion is sandwiched between the permanent magnet housing holes in the circumferential direction of the rotor core. Fan-shaped part Both ends in the radial and circumferential directions of The sector end region is The present invention is characterized in that it is formed in a [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing the configuration of a rotating electric machine according to a first embodiment. [Diagram 2] 1 is a vertical sectional view showing the configuration of a rotating electric machine according to a first embodiment. [Diagram 3] 2 is a partial cross-sectional view showing the configuration of an inter-pole portion of the interior magnet rotor according to the first embodiment. FIG. [Figure 4] FIG. 1 is a partial cross-sectional view showing an example of a conventional embedded magnet rotor for explaining the effects of the embedded magnet rotor according to the first embodiment. [Diagram 5] FIG. 11 is a partial cross-sectional view showing the configuration of an inter-pole portion of an embedded magnet rotor according to a second embodiment. [Figure 6] FIG. 11 is a partial cross-sectional view showing the configuration of a portion between magnetic poles of an embedded magnet rotor according to a third embodiment. [Figure 7]FIG. 11 is a cross-sectional view showing the configuration of a rotating electric machine according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an interior permanent magnet rotor and a rotating electric machine according to an embodiment of the present invention will be described with reference to the drawings. Here, the same or similar parts are given the same reference numerals and duplicated explanations will be omitted.

[0014] [First embodiment] Fig. 1 is a cross-sectional view showing the configuration of a rotating electric machine 200 according to the first embodiment, and Fig. 2 is a vertical cross-sectional view showing the configuration of the rotating electric machine 200 according to the first embodiment.

[0015] The rotating electric machine 200 includes an embedded magnet type rotor 100 having a rotor shaft 110 extending in the direction of the rotation axis, a rotor core 120 attached to the rotor shaft 110, and a plurality of permanent magnets 130 (see FIG. 3), a stator 10 having a cylindrical stator core 11 with stator teeth 11a formed thereon and arranged radially outside the rotor core 120 so as to surround the rotor core 120 via a gap space 15, and two bearings (not shown) that rotatably support the rotor shaft 110.

[0016] The rotor core 120 has a plurality of electromagnetic steel sheets 120a stacked in the direction of the rotation axis. Each electromagnetic steel sheet 120a has a punched-out portion through which the rotor shaft 110 passes and a punched-out portion through which the permanent magnets 130 pass. By stacking the plurality of electromagnetic steel sheets 120a, a rotor shaft through hole 110h (FIG. 2) extending in the direction of the rotation axis and a plurality of permanent magnet storage holes 121 (FIG. 1) are formed in the rotor core 120.

[0017] Two permanent magnet storage holes 121 are formed in a V-shaped configuration that protrudes radially inward, sandwiching the respective d-axes and center bridge 126. Note that, although Fig. 1 shows an example in which the V-shaped configuration is formed in one layer in the radial direction, this is not limiting, and multiple V-shaped configurations may be formed in the radial direction.

[0018] The permanent magnet 130 is plate-shaped. Although the permanent magnet 130 is shown in Fig. 1 as an example having a flat plate shape, the permanent magnet 130 may have a curved shape in a cross section perpendicular to the rotation axis of the rotor shaft 110 (vertical cross section), for example.

[0019] In order to prevent the permanent magnets 130 from protruding outward in the rotational axis direction from the rotor core 120, two end plates 140 are provided at both ends in the rotational axis direction of the rotor core 120. The end plates 140 have an outer diameter smaller than that of the rotor core 120 for reasons such as covering the area in which the permanent magnets 130 are arranged in the vertical cross section, and ensuring as much insulation distance as possible from the coil end portions 12a, which will be described later, because a high voltage is applied to the coil end portions 12a. Also, the end plates 140 have an outer diameter larger than the outer diameter of the outermost envelope cylinder in the radial direction of the permanent magnets 130 housed in the rotor core 120.

[0020] The region of rotor core 120 close to end plate 140 is referred to as end plate vicinity region 120n (FIG. 2). Here, end plate vicinity region 120n refers to a range including electromagnetic steel plate 120a, which may cause deformation of the radially outer portion of electromagnetic steel plate 120a and damage to the rotor due to the outer shape of end plate 140 being smaller than the outer diameter of rotor core 120.

[0021] A plurality of stator teeth 11 for winding stator windings 12 (FIG. 2) are formed at intervals in the circumferential direction on the inner peripheral side of the stator 10. The stator windings 12 have coil end portions 12a disposed outward in the rotation axis direction from the end of the stator core 11.

[0022] FIG. 3 is a partial cross-sectional view showing the configuration of the inter-pole portion of the interior magnet rotor 100 according to the first embodiment.

[0023] The permanent magnet storage holes 121 of adjacent magnetic poles are arranged on either side of the d-axis and the center bridge 126, and move away from each other radially outward. Therefore, the portion of the rotor core 120 that is sandwiched between the permanent magnet storage holes 121 in the circumferential direction forms a fan-shaped portion 123 that spreads out circumferentially from the center bridge 126 radially outward.

[0024] The plurality of electromagnetic steel plates 120 a in the end plate vicinity region 120 n of the rotor core 120 have joints 125 formed in the sector end regions 123 a of the sector portions 123 .

[0025] Here, the sector end region 123a refers to a portion of the sector 123 that is radially outboard of the end plate 140 and that is in the vicinity of both ends in the circumferential direction.

[0026] In this embodiment, the joint portion 125 is a crimped portion 125a. For example, as shown in FIG. 3, a hole is formed in the electromagnetic steel sheet 120a on the side closer to the end plate 140, and a part of the electromagnetic steel sheet 120a on the side farther from the end plate 140 is bent outward to bend the electromagnetic steel sheets 120a. For example, the joint portion 125 may be formed in a group of several sheets to about 10 sheets. Alternatively, a plurality of such groups of electromagnetic steel sheets 120a may be provided in the direction of the rotation axis. Alternatively, all the electromagnetic steel sheets 120a may be configured in the same group.

[0027] FIG. 4 is a partial cross-sectional view showing an example of a conventional embedded magnet rotor for explaining the effect of the embedded magnet rotor according to the first embodiment.

[0028] In the conventional example, the force acting on the sector portion 123 due to the centrifugal force acting on the permanent magnet 130 and the wind pressure caused by the rotation of the rotor cause deformation and curling up of the sector portion end region 123a of the electromagnetic steel sheet 120a in the end plate vicinity region 120n.

[0029] In the embedded magnet rotor 100 according to the present embodiment, the conventional shape is maintained, but by providing a connecting portion 125 in the sector end region 123a of at least the electromagnetic steel sheet 120a in the end plate vicinity region 120n, it is possible to prevent deformation of the ends of the electromagnetic steel sheets that make up the rotor core.

[0030] Second Embodiment FIG. 5 is a partial cross-sectional view showing the configuration of the inter-pole portion of the interior magnet type rotor according to the second embodiment.

[0031] This embodiment is a modification of the first embodiment. In this embodiment, the joint 125 is formed by the electromagnetic steel plates 120a bonded to each other at the sector portion 123. The joint 125b is formed on at least the electromagnetic steel plates 120a in the end plate vicinity region 120n.

[0032] 5 shows an example in which the bonding area is the entire sector portion 123, but the present invention is not limited to this. It is sufficient that the bonding area is formed at least on the outer periphery of the end plate 140 of the electromagnetic steel plate 120a.

[0033] In the interior magnet rotor 100 according to the present embodiment, the joints 125 can be formed simply by applying an adhesive, without processing the electromagnetic steel plate 120a, and the same effects as in the first embodiment can be obtained.

[0034] Third embodiment FIG. 6 is a partial cross-sectional view showing the configuration of an inter-pole portion of an interior magnet rotor 100 according to a third embodiment.

[0035] This embodiment is a modification of the first embodiment. In this embodiment, the joint 125 is a welded portion 125c. As shown by the dashed ellipse in Fig. 6, the welded portion 125c is formed at the end of the sector portion end region 123a at least in the electromagnetic steel plate 120a of the end plate vicinity region 120n. The welded portion 125c may be formed by spot welding at one or more points.

[0036] In the interior magnet rotor 100 according to this embodiment, the joints 125 can be formed simply by spot welding the electromagnetic steel plate 120a, for example, and the same effects as in the first embodiment can be obtained.

[0037] [Fourth embodiment] 7 is a cross-sectional view showing the configuration of a rotating electric machine 200a according to a fourth embodiment. This embodiment is a modification of the first embodiment.

[0038] In the first to third embodiments, when the outer diameter of the end plate 140 is smaller than the outer diameter of the rotor core 120, the coupling portions 125 are provided on the multiple electromagnetic steel plates 120a in the end plate vicinity region 120n.

[0039] On the other hand, in the interior permanent magnet rotor 100a of the rotating electric machine 200a according to this embodiment, the outer diameter of the end plate 141 is substantially equal to the outer diameter of the rotor core 120. Here, "substantially equal" refers to equal within the range of error including manufacturing error, measurement error, and the like.

[0040] The end plate 141 has a non-magnetic portion 141a and an annular insulator portion 141b disposed radially outward of the non-magnetic portion 141a. The annular insulator portion 141b is made of an insulating material such as a resin or a carbon compound such as silicon carbide.

[0041] The contact surface between the non-magnetic part 141a and the annular insulating part 141b is tapered so that the tightening force of the non-magnetic part 141a is transmitted to the annular insulating part 141b. The tapered surface is tapered from the radially outer side toward the radially inner side in the direction from the outer side toward the inner side (rotor core 120 side) in the rotation axis direction of the end plate 141, that is, the diameter of the tapered surface is reduced. The non-magnetic part 141a and the annular insulating part 141b may be bonded to each other with an adhesive or the like.

[0042] As described above, in the interior magnet rotor 100a according to this embodiment, by using the end plates 141, it is possible to use the conventional electromagnetic steel plates 120a as they are, and it is possible to obtain the same effects as in the first embodiment.

[0043] According to the embodiments described above, it is possible to provide an interior permanent magnet rotor and a rotating electric machine that can prevent deformation of the ends of the electromagnetic steel plates that make up the rotor core.

[0044] [Other embodiments] Although the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention. In addition, the features of each embodiment may be combined. Furthermore, the embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. The embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and gist of the invention. [Explanation of symbols]

[0045] 10... stator, 11... stator core, 11a... stator teeth, 12... stator winding, 12a... coil end portion, 15... gap space, 100... embedded magnet type rotor, 110... rotor shaft, 110a... shaft flange, 120... rotor core, 120a... electromagnetic steel plate, 120n... end plate vicinity region, 121... permanent magnet storage hole, 122... communication opening, 123... sector portion, 123a... sector portion end region, 123b... center bridge, 123f... center flux barrier, 125... joint portion, 125a... crimp portion, 125b... adhesive portion, 125c... welded portion, 130... permanent magnet, 140, 141... end plate, 141a... non-magnetic portion, 141b... annular insulator portion, 200... rotating electric machine

Claims

1. A rotor shaft extending in a rotation axis direction; a rotor core having a plurality of electromagnetic steel plates laminated in the direction of the rotation axis, attached to the radially outer side of the rotor shaft, and having two permanent magnet storage holes formed in the radially outer portion thereof, the permanent magnet storage holes being spaced apart from each other in the circumferential direction and arranged in a convex manner toward the radially inner side on either side of the d axis; A plate-shaped permanent magnet is housed in each of the permanent magnet housing holes; two end plates having an outer diameter smaller than an outer diameter of the rotor core, the end plates being disposed at both ends of the plurality of electromagnetic steel sheets in the rotational axis direction to prevent the permanent magnets from protruding outward in the rotational axis direction; An interior magnet rotor having The permanent magnet storage hole communicates with the outside of the outer circumferential surface of the rotor core, the plurality of electromagnetic steel sheets in a region adjacent to the end plates in the rotation axis direction of the rotor core have joints that join the plurality of electromagnetic steel sheets to each other to prevent deformation due to wind pressure generated by rotation, The coupling portion is formed in a sector-shaped portion end region that is an end portion on both radial and circumferential sides of a sector-shaped portion that is sandwiched between the permanent magnet housing holes in the circumferential direction of the rotor core. An embedded magnet rotor.

2. 2. The embedded magnet rotor according to claim 1, wherein each of the two end plates has an outer diameter larger than an outer diameter of a radially outermost envelope cylinder of the permanent magnet housed in the rotor core.

3. 3. The interior magnet rotor according to claim 1, wherein the joints are welds formed in end regions of the sector-shaped portions of the plurality of electromagnetic steel plates in a region adjacent to the end plates.

4. 3. The embedded magnet rotor according to claim 1, wherein the joint portion is an adherend portion formed at least in the end region of the sector portion of the plurality of electromagnetic steel sheets in the vicinity of the end plate.

5. A rotor shaft extending in a rotation axis direction; a rotor core having a plurality of electromagnetic steel plates laminated in the direction of the rotation axis, attached to the radially outer side of the rotor shaft, and having two permanent magnet storage holes formed in the radially outer portion thereof, the permanent magnet storage holes being spaced apart from each other in the circumferential direction and arranged in a V-shape on either side of the d-axis; A plate-shaped permanent magnet is housed in each of the permanent magnet housing holes; two end plates having an outer diameter substantially equal to the outer diameter of the rotor core, the radially outer portions of which are annular insulators; having the plurality of electromagnetic steel sheets in a region adjacent to the end plates in the rotation axis direction of the rotor core have joints that join the plurality of electromagnetic steel sheets to each other to prevent deformation due to wind pressure generated by rotation, The coupling portion is formed in a sector-shaped portion end region that is an end portion on both radial and circumferential sides of a sector-shaped portion that is sandwiched between the permanent magnet housing holes in the circumferential direction of the rotor core. An embedded magnet rotor.

6. The embedded magnet type rotor according to claim 1 or 5, A stator disposed radially outside the rotor core; A rotating electric machine comprising:

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