Embedded magnet-type rotor and rotating electric machine

Abstract

To provide an embedded magnet-type rotor and a rotating electric machine that enable positioning of inner iron core and outer iron cores.SOLUTION: According to an embodiment, an embedded magnet-type rotor 30 is provided with: a rotor shaft; a rotor core 10 attached to an outer periphery of the rotor shaft; and permanent magnets 3 provided in the rotor core 10 and disposed to form a pair or a plurality of pairs with each other at each magnetic pole part. The rotor core 10 is provided with: an inner iron core 12 attached to the outer periphery of the rotor shaft; a fan-shaped outer iron core in each magnetic pole part; a filling member that fills the space between the inner iron core and each outer iron core; and a positioning member capable of maintaining relative positions of the inner iron core and the respective outer iron cores. The inner iron core and each outer iron core are formed to be engaged with each other via the filling member.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Permanent magnet rotors generally include embedded magnet rotors in which permanent magnets are arranged inside the rotor core, and surface magnet rotors in which permanent magnets are arranged on the outer periphery of the rotor core.

[0003] In an embedded magnet type rotor, a method is often adopted in which a storage hole for storing a permanent magnet is formed in the rotor core, and the permanent magnet is press-fitted into this storage hole.

[0004] Here, the permanent magnet is a sintered material similar to china, and is brittle with a large dimensional tolerance, so chips and scratches are likely to occur in the part that comes into contact with the wall of the storage hole when it is pressed in. In addition, if the surface of the permanent magnet is coated with an anti-rust agent or the like, the coating is likely to peel off. Furthermore, when the permanent magnet is pressed in, each electromagnetic steel sheet that constitutes the rotor core is deformed non-uniformly so as to bulge outward in the radial direction, resulting in unevenness on the side peripheral surface of the rotor core, which causes magnetic noise, torque ripple, etc. To avoid these problems, a process such as polishing is required to improve the dimensional tolerance of the permanent magnet, but such an additional process leads to a significant increase in costs.

[0005] To solve this problem and reduce leakage flux, a method has been proposed that does not provide a top bridge (a bridge on the outer periphery) and a center bridge (a bridge on the d-axis between the magnets). In other words, a method has been proposed in which the radially outer part and the radially inner part of each magnetic pole are separated and these are assembled together with the permanent magnet.

[0006] Fig. 6 is a partial cross-sectional view showing a conventional example of an interior magnet rotor 1. As described above, in Fig. 6, rotor core 10 of interior magnet rotor 1 has inner core 12 which is the radially inner portion, and outer core 11 which is the radially outer portion of each magnetic pole portion 3a. Outer core 11 and inner core 12 are separated from each other and are separate bodies.

[0007] Outer core 11 has outer core extension 11a extending radially inward, and two outer core engagement portions 11b connected to the innermost part of outer core extension 11a and extending on both sides in the circumferential direction. Inner core 12 has two inner core engagement portions 12a formed to engage with outer core engagement portions 11b of outer core 11. Outer core engagement portion 11b and inner core engagement portion 12a have overlapping portions when viewed from the radially inner side to the radially outer side.

[0008] A part of the space formed by outer core 11 and inner core 12 serves as magnet housing hole 15 for housing permanent magnet 3.

[0009] At least a portion of magnet storage hole 15 and the space between outer core engagement portion 11b and inner core engagement portion 12a are filled with filling material 18. Outer core 11 and inner core 12 are connected and integrated by filling material 18. As a result, when interior magnet type rotor 1 is rotating, centrifugal force acting on permanent magnet 3 and outer core 11 is transmitted from outer core engagement portion 11b to inner core engagement portion 12a via filling material 18. In other words, even during rotation, permanent magnet 3 and outer core 11 are held by inner core engagement portion 12a, overcoming the centrifugal force.

[0010] With this configuration, it is possible to assemble outer core 11, permanent magnet 3, and inner core 12. Therefore, there is no need to press-fit permanent magnet 3 into magnet housing hole 15 of rotor core 10. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] JP 2011-109786 A Summary of the Invention [Problem to be solved by the invention]

[0012] The embedded magnet rotor 1 shown in FIG. 6 has the advantage that there is no need to press-fit the permanent magnets 3 into the magnet storage holes 15 of the rotor core 10, and therefore no problems associated with press-fitting. However, it also has significant problems.

[0013] That is, when filling material 18 is filled between outer core 11 and inner core 12 and integrated, outer core 11 and inner core 12 need to be in a predetermined relative positional relationship. That is, inner core 12 and the same number of outer cores 11 as magnetic pole portions 3a need to be arranged in predetermined relative positions, and the relative positional relationship between outer core 11, inner core 12 and permanent magnet 3 needs to be maintained until filling material 18 is poured and solidified.

[0014] If accurate positioning is not possible, the outer periphery of outer core 11 must be positioned radially inward to avoid contact between interior magnet rotor 1 and the stator. In other words, the outer diameter of the rotor must be made small to increase the gap width between the rotor and the stator. As a result of the larger gap width, there is an issue that magnetic resistance increases, reducing torque performance or causing variation in torque performance.

[0015] On the other hand, in order to perform accurate positioning, a dedicated jig or device is required, and the number of steps required for positioning is increased, resulting in an increase in manufacturing costs.

[0016] An object of the present invention is to provide an interior permanent magnet rotor and a rotating electric machine that enable positioning of outer core 11 and inner core 12. [Means for solving the problem]

[0017] In order to achieve the above-mentioned object, an embedded magnet type rotor according to an embodiment of the present invention is an embedded magnet type rotor comprising a rotor shaft extending in the direction of rotation axis, a rotor core attached to the outer periphery of the rotor shaft, and permanent magnets provided within the rotor core and arranged in one or more pairs circumferentially at each magnetic pole portion, wherein the rotor core comprises an inner core attached to the outer periphery of the rotor shaft and having a permanent magnet supporting inner recess formed to support each of the permanent magnets, a fan-shaped outer core arranged radially outside the inner core at each of the magnetic pole portions, a filling member filled between the inner core and the outer core, and a positioning member capable of maintaining the relative position of the inner core and each of the outer cores, and wherein the inner core and the outer core are formed so that the inner core and the outer core engage with each other via the filling member at the radially innermost part of the outer core. [Brief description of the drawings]

[0018] [Figure 1] 1 is a vertical sectional view showing a rotating electric machine according to a first embodiment. [Diagram 2] 1 is a cross-sectional view showing a rotating electric machine according to a first embodiment. [Diagram 3] FIG. 1 is a partial cross-sectional view showing an interior magnet rotor according to a first embodiment. [Figure 4] FIG. 11 is a partial cross-sectional view showing an interior magnet rotor according to a second embodiment. [Diagram 5] FIG. 11 is a partial cross-sectional view showing an interior magnet rotor according to a third embodiment. [Figure 6] FIG. 1 is a partial cross-sectional view showing a conventional example of an embedded magnet type rotor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an interior permanent magnet rotor and a rotating electric machine using the same 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.

[0020] [First embodiment] Fig. 1 is a longitudinal sectional view showing a rotating electric machine 100 according to the first embodiment. Also, Fig. 2 is a transverse sectional view showing the rotating electric machine 100 according to the first embodiment. That is, Fig. 1 shows a cross section of the rotating electric machine 100 along a vertical plane including a rotation axis CL, and Fig. 2 shows a cross section of the rotating electric machine 100 along a plane perpendicular to the rotation axis CL.

[0021] The rotating electric machine 100 has an embedded magnet rotor 30, a stator 40 arranged radially outside the embedded magnet rotor 30 via a gap portion 5 to surround the embedded magnet rotor 30, a bearing 50, and a housing 60 that houses the stator 40, etc. and statically supports the bearing 50.

[0022] The stator 40 has a stator core 41 and a stator winding 42 having a portion accommodated in a plurality of stator slots 41a (FIG. 2) formed in the stator core 41.

[0023] The embedded magnet rotor 30 has a rotor shaft 2 extending in the rotation axis direction (hereinafter referred to as the axial direction) and rotatably supported by bearings, a rotor core 10 attached to the rotor shaft 2, and a plurality of permanent magnets 3 embedded in the rotor core 10.

[0024] As shown in Fig. 2, the multiple permanent magnets 3 are arranged such that two permanent magnets in each magnetic pole portion 3a form one or more pairs in the circumferential direction. Fig. 2 shows an eight-pole rotor having eight magnetic pole portions 3a. Each permanent magnet 3 is arranged such that its north pole-south pole direction is oriented such that magnetic flux is generated between adjacent magnetic pole portions 3a.

[0025] Fig. 3 is a partial cross-sectional view showing the interior magnet rotor 30 according to the first embodiment. Fig. 3 shows the portion of each magnetic pole portion 3a.

[0026] In each magnetic pole portion 3a, as described above, two permanent magnets 3 are arranged in one pair or multiple pairs in the circumferential direction. Specifically, the two permanent magnets 3 are arranged in a V shape extending radially outward. Each permanent magnet 3 is housed in a magnet housing hole 15.

[0027] In each magnetic pole portion 3a, rotor core 10 has inner core 12 attached directly to rotor shaft 2 (FIG. 1) and outer core 11 disposed radially outward. That is, rotor core 10 has one inner core 12 and the same number of outer cores 11 as the number of magnetic pole portions 3a.

[0028] Outer core 11 is in the shape of a sector spreading outward in the radial direction, and at each magnetic pole portion 3a, inner core 12 has a corresponding sector-shaped recess.

[0029] In each magnetic pole portion 3a, inner core 12 and outer core 11 form two magnet storage holes 15 that respectively store two permanent magnets 3. An outer space 16 is formed radially outside magnet storage hole 15, and communicates with gap portion 5 outside rotor core 10. The space including magnet storage hole 15 between inner core 12 and outer core 11 is filled with filling member 18. Here, filling member 18 is a resin such as a thermosetting resin. Filling member 18 fills the entire magnet storage hole 15 or its radially inner portion, and the radially inner space of magnet storage hole 15.

[0030] Inner core 12 and outer core 11 have engagement portions 14 at the radially inner portion of outer core 11, which engage with each other via filler member 18. Outer core 11 has outer core extension portion 11a extending toward the radially innermost portion, and the radially innermost portion of outer core extension portion 11a is connected to two outer core engagement portions 11b formed to extend on both sides in the circumferential direction. In addition, inner core 12 has inner core engagement portions 12a arranged radially outward of each outer core engagement portion 11b.

[0031] Filling material 18 is filled between two outer core engaging portions 11b and two inner core engaging portions 12a. Filling material 18 filled between two outer core engaging portions 11b and two inner core engaging portions 12a forms engaging portion 14. Engaging portion 14 prevents outer core 11 from moving radially outward due to centrifugal force, and has a function of preventing outer core 11 from coming off.

[0032] Two positioning inner bridges 21 are provided between the inner circumferential surface of outer core engaging portion 11b of outer core 11 and inner core 12 opposing thereto.

[0033] Positioning inner bridge 21 is not a strength member that resists the centrifugal force acting on outer core 11 and permanent magnets 3. In this regard, strength is ensured by integrating outer core 11 and inner core 12 with engaging portion 14 and filling member 18. Positioning inner bridge 21 as positioning member 20 only needs to have the strength required for the positioning function of maintaining the relative positional relationship between inner core 12 and each outer core 11 when assembling rotor core 10. In other words, as long as it has the width required for the positioning function, it is preferable that the width be as narrow as possible from the viewpoint of suppressing an increase in leakage flux.

[0034] In interior magnet rotor 30 of the present embodiment configured as described above, inner core 12 and each outer core 11 are connected by positioning inner bridges 21 at each engagement portion 14. Therefore, even when rotor core 10 is assembled, the relative positional relationship between inner core 12 and each outer core 11 is maintained and they do not shift relative to each other. That is, each engagement portion 14 has a positioning function. By suppressing variation in the relative position between outer core 11 and inner core 12, variation in torque performance is suppressed, resulting in improved torque performance.

[0035] Furthermore, since the positioning inner bridge 21 has a width as narrow as possible while still ensuring a width necessary for the positioning function, an increase in leakage flux is also kept to a minimum.

[0036] [Second embodiment] 4 is a partial cross-sectional view showing an embedded magnet rotor 30a according to a second embodiment. This embodiment is a modification of the first embodiment, and differs in part in the configuration of the engagement portion 14. The rest is the same as the first embodiment.

[0037] Specifically, there are two outer core extensions 11a in the circumferential direction, and extension barrier 11c is formed between them. As a result, the rigidity of the base of sector-shaped outer core 11 can be improved. Furthermore, if the rigidity value is maintained at the value for one extension, the total value of the widths of two outer core extensions 11a of this embodiment can be made smaller than the width of outer core extension 11a of the first embodiment. As a result, the width of the magnetic path of leakage flux can be reduced, and thus the leakage flux can be reduced.

[0038] [Third embodiment] 5 is a partial cross-sectional view showing an embedded magnet type rotor 30b according to a third embodiment. This embodiment is a modification of the first embodiment. This embodiment differs from the first embodiment in the positioning member 20. The rest is the same as the first embodiment.

[0039] In this embodiment, a positioning outer periphery bridge 22 is provided as a positioning member 20 instead of the positioning inner bridge 21 in the first embodiment.

[0040] Positioning outer bridge 22 is provided so as to straddle the communication portion between gap portion 5 of outer space 16 adjacent to the radial outside of each magnet storage hole 15. In other words, positioning outer bridge 22 is provided so as to connect the outer periphery of outer core 11 and the outer periphery of inner core 12.

[0041] Positioning outer periphery bridge 22 as positioning member 20 is not a strength member for resisting bending forces applied to outer core 11. In this respect, strength is ensured by integrating outer core 11 and inner core 12 with engaging portion 14 and filling member 18. Like positioning inner bridge 21 in the first embodiment, positioning outer periphery bridge 22 as positioning member 20 only needs to have the strength required for the positioning function of maintaining the relative positional relationship between inner core 12 and each outer core 11 when assembling rotor core 10. In other words, as long as it has the width required for the positioning function, it is preferable that the width be as narrow as possible from the viewpoint of suppressing an increase in leakage flux.

[0042] In interior magnet rotor 30b of the present embodiment configured as described above, inner core 12 and each outer core 11 are connected by positioning outer periphery bridges 22 at each engagement portion 14. Therefore, even when rotor core 10 is assembled, the relative positional relationship between inner core 12 and each outer core 11 is maintained and they do not become misaligned with each other. By suppressing variation in the relative position between outer core 11 and inner core 12, variation in torque performance is suppressed, resulting in improved torque performance.

[0043] Furthermore, since the positioning outer bridge 22 has a width as narrow as possible while still ensuring the width necessary for the positioning function, an increase in leakage flux is also kept to a minimum.

[0044] According to the embodiment described above, it is possible to provide an interior permanent magnet rotor and a rotating electric machine that enable the positioning of outer core 11 and inner core 12.

[0045] [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. For example, the features of the second embodiment may be combined with the features of the third embodiment. 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 within the scope and gist of the invention as well as the invention and its equivalents as described in the claims. [Explanation of symbols]

[0046] 1... embedded magnet rotor, 2... rotor shaft, 3... permanent magnet, 3a... magnetic pole portion, 5... gap portion, 10... rotor core, 11... outer core, 11a... outer core extension portion, 11b... outer core engagement portion, 11c... extension barrier, 12... inner core, 12a... inner core engagement portion, 13... outer barrier, 14... engagement portion, 15... magnet storage hole, 16... outer space, 18... filling member, 20... positioning member, 21... positioning outer periphery bridge, 22... positioning inner bridge, 30, 30a, 30b... embedded magnet rotor, 40... stator, 41... stator core, 41a... stator slot, 42... stator winding, 50... bearing, 60... housing, 100... rotating electric machine

Claims

1. A rotor shaft extending in a rotation axis direction; a rotor core attached to an outer periphery of the rotor shaft; Permanent magnets are provided in the rotor core, and are arranged in one or more pairs in the circumferential direction at each magnetic pole portion; An embedded magnet rotor comprising: The rotor core is an inner core attached to an outer periphery of the rotor shaft; In each of the magnetic pole portions, a sector-shaped outer core is disposed radially outward of the inner core; a filler member filled between the inner core and the outer core; a positioning member capable of maintaining a relative position between the inner core and each of the outer cores; Equipped with the inner core and the outer core are formed such that the inner core and the outer core are engaged with each other via the filling member at the radially innermost part of the outer core. An embedded magnet rotor.

2. The radially innermost portion of each of the outer cores has two outer core engaging portions formed so as to extend on both sides in the circumferential direction, the inner core has inner core engaging portions disposed radially outward of each of the outer core engaging portions, The positioning member has at least one positioning inner bridge connecting each of the outer core engaging portions and the inner core engaging portion.

2. The interior magnet rotor according to claim 1 .

3. 3. The interior magnet rotor according to claim 2, wherein the outer core has two parallel outer core extensions that connect to the outer core engagement portion.

4. The positioning member has a positioning outer periphery bridge that connects adjacent portions of the outer periphery of the outer core and the outer periphery of the inner core in the circumferential direction.

2. The interior magnet rotor according to claim 1 .

5. The embedded magnet type rotor according to any one of claims 1 to 4, a stator disposed radially outside the embedded magnet rotor; a bearing that rotatably supports the rotor shaft; A rotating electric machine comprising:

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