Embedded magnet type rotor and rotating electric machine

Abstract

The invention relates to an embedded magnet type rotor and a rotating electric machine. According to one embodiment, an embedded magnet type rotor (30) is provided with a rotor shaft, a rotor core (10) attached to the outer periphery of the rotor shaft, and permanent magnets (3) provided inside the rotor core (10) and arranged so as to form one or more pairs on each magnetic pole portion. A rotor core (10) is provided with: an inner core (12) attached to the outer periphery of a rotor shaft; a fan-shaped outer iron core of each magnetic pole part; a filling member filled between the inner core and the outer core; and a positioning member capable of maintaining the relative position between the inner core and each of the outer cores. The inner core and the outer core are formed so as to engage with each other via the filling member.

Description

Technical Field

[0001] The present invention relates to an embedded magnet rotor and a rotary electric motor using the embedded magnet rotor. Background Technology

[0002] In permanent magnet rotors, there are generally embedded magnet rotors where the permanent magnets are placed in the rotor core and surface magnet rotors where the permanent magnets are placed on the outer periphery of the rotor core.

[0003] In embedded magnet rotors, a common method is to form a storage hole on the rotor core to hold the permanent magnet and press the permanent magnet into the storage hole.

[0004] Here, the permanent magnets are sintered materials similar to ceramics, making them brittle and with large dimensional tolerances. Therefore, the parts in contact with the walls of the receiving holes are prone to defects and damage during pressing. Furthermore, if a coating such as a rust inhibitor is applied to the surface of the permanent magnet, this coating is easily peeled off. Moreover, because the permanent magnets are pressed in, the individual electromagnet plates constituting the rotor core deform unevenly, bulging outwards in the radial direction. This results in unevenness on the side surface of the rotor core, causing magnetic noise and torque fluctuations. To avoid these problems and improve the dimensional tolerances of the permanent magnets, grinding and other processes are required, but these additional processes significantly increase costs.

[0005] To address this issue and reduce magnetic leakage flux, a method is proposed that eliminates the need for a top bridge (the bridge on the outer periphery) and a central bridge (the bridge on the d-axis between the magnets). Specifically, a method is proposed that separate the radially outer portion from the radially inner portion within each magnetic pole section and assemble them together with the permanent magnet.

[0006] Figure 6 This is a partial cross-sectional view showing a conventional example of an embedded magnet rotor 1. Figure 6 As described above, the rotor core 10 of the embedded magnet rotor 1 has an inner core 12 as a radially inner portion and an outer core 11 as a radially outer portion of each magnetic pole portion 3a. The outer core 11 and the inner core 12 are separate from each other and are independent of each other.

[0007] The outer core 11 has an outer core extension 11a extending radially inward and two outer core engaging portions 11b connected to the innermost part of the outer core extension 11a and extending circumferentially to both sides. The inner core 12 has two inner core engaging portions 12a formed to engage with the outer core engaging portions 11b of the outer core 11. When viewed from radially inward to radially outward, the outer core engaging portions 11b and the inner core engaging portions 12a have overlapping portions.

[0008] A portion of the space formed by the outer iron core 11 and the inner iron core 12 becomes a magnet storage hole 15 for storing the permanent magnet 3.

[0009] A filling member 18 is filled in at least a portion of the magnet receiving hole 15 and in the space between the outer core engaging portion 11b and the inner core engaging portion 12a. The outer core 11 and the inner core 12 are connected and integrated by the filling member 18. As a result, in the rotating state of the embedded magnet rotor 1, the centrifugal force acting on the permanent magnet 3 and the outer core 11 is transmitted from the outer core engaging portion 11b to the inner core engaging portion 12a via the filling member 18. That is, even during rotation, the permanent magnet 3 and the outer core 11 are held in place by the inner core engaging portion 12a against the centrifugal force.

[0010] By adopting this structure, the outer iron core 11, the permanent magnet 3, and the inner iron core 12 can be assembled. Therefore, it is not necessary to press the permanent magnet 3 into the magnet storage hole 15 of the rotor iron core 10.

[0011] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2011-109786 Summary of the Invention

[0012] The problem that the invention aims to solve exist Figure 6 The embedded magnet rotor 1 shown has the advantage of not requiring the permanent magnet 3 to be pressed into the magnet storage hole 15 of the rotor core 10 and without the problem of pressing in, but the other side also has a large problem.

[0013] That is, when the outer iron core 11 and the inner iron core 12 are integrated by filling the space between the filling component 18, the outer iron core 11 and the inner iron core 12 need to be in a predetermined positional relationship. That is, the inner iron core 12 and the number of outer iron cores 11 containing magnetic pole portions 3a need to be arranged in a predetermined relative position, and the filling component 18 needs to be injected, and the relative positional relationship of the outer iron core 11, the inner iron core 12 and the permanent magnet 3 needs to be maintained before it solidifies.

[0014] In situations where precise positioning is not possible, to avoid contact between the embedded magnet rotor 1 and the stator, the outer periphery of the outer iron core 11 needs to be positioned radially inward. That is, the outer diameter of the rotor needs to be reduced, thus increasing the gap width between the rotor and the stator. This increased gap width results in issues such as increased magnetic reluctance, reduced torque performance, or uneven torque performance.

[0015] On the other hand, accurate positioning requires specialized fixtures and devices, and the positioning process also increases, leading to higher manufacturing costs.

[0016] The purpose of this invention is to provide an embedded magnet rotor and a rotary motor capable of positioning the outer iron core 11 and the inner iron core 12.

[0017] Methods for solving problems To achieve the above objectives, the embedded magnet rotor according to embodiments of the present invention comprises: a rotor shaft extending along a rotation axis; a rotor core mounted on the outer periphery of the rotor shaft; and permanent magnets disposed within the rotor core, arranged in pairs or more in each magnetic pole portion in a circumferential direction. In the embedded magnet rotor, the rotor core has: an inner core mounted on the outer periphery of the rotor shaft, having a permanent magnet support inner recess formed to support each of the permanent magnets; a fan-shaped outer core disposed radially outward of the inner core in each of the magnetic pole portions; a filling member filling between the inner core and the outer core; and a positioning member capable of maintaining the relative position between the inner core and each of the outer cores. 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 inner core radially innermost of the outer core. Attached Figure Description

[0018] Figure 1 This is a longitudinal cross-sectional view of the rotary electric motor according to the first embodiment.

[0019] Figure 2 This is a cross-sectional view of the rotary electric motor according to the first embodiment.

[0020] Figure 3 This is a partial cross-sectional view showing the embedded magnet rotor of the first embodiment.

[0021] Figure 4 This is a partial cross-sectional view showing the embedded magnet rotor of the second embodiment.

[0022] Figure 5 This is a partial cross-sectional view showing the embedded magnet rotor of the third embodiment.

[0023] Figure 6 This is a partial cross-sectional view showing a conventional example of an embedded magnet rotor. Detailed Implementation

[0024] Hereinafter, with reference to the accompanying drawings, an embodiment of the embedded magnet rotor of the present invention and a rotary electric motor using the embedded magnet rotor will be described. Common symbols will be used to denote identical or similar parts, and repeated descriptions will be omitted.

[0025] [First Implementation Method] Figure 1 This is a longitudinal cross-sectional view showing the rotary motor 100 according to the first embodiment. Additionally, Figure 2 This is a cross-sectional view showing the rotary motor 100 according to the first embodiment. That is, Figure 1 This represents a cross-section of the rotary motor 100 along a plane containing the vertical direction of the rotation axis CL. Figure 2 This represents the cross section of the rotary motor 100 along a plane perpendicular to the rotation axis CL.

[0026] The rotary electric motor 100 includes a rotor 30 with embedded magnets, a stator 40 arranged radially outside the rotor 30 with the embedded magnets 30 surrounded by a gap 5, a bearing 50, and a housing 60 that houses the stator 40 and the bearing 50 and provides static support.

[0027] The stator 40 has a stator core 41 and a stator winding 42, the stator winding 42 having multiple stator slots 41a housed in the stator core 41. Figure 2 (part of)

[0028] The embedded magnet rotor 30 has a rotor shaft 2 extending along the rotation axis (hereinafter referred to as the axial direction) and supported by bearings to be rotatable, a rotor core 10 mounted on the rotor shaft 2, and a plurality of permanent magnets 3 embedded in the rotor core 10.

[0029] like Figure 2 As shown, multiple permanent magnets 3 are arranged in each magnetic pole section 3a in such a way that two permanent magnets are paired or more pairs of each other in the circumferential direction. Figure 2 The case described here is an 8-pole rotor with 8 magnetic pole sections 3a. The orientation of the N-S poles of each permanent magnet 3 is configured such that magnetic flux is generated between adjacent magnetic pole sections 3a.

[0030] Figure 3 This is a partial cross-sectional view of the embedded magnet rotor 30 according to the first embodiment. Figure 3 Parts of each magnetic pole section 3a are shown.

[0031] In each magnetic pole section 3a, as described above, two permanent magnets 3 are arranged in one or more pairs relative to each other 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 within a magnet housing hole 15.

[0032] In each magnetic pole section 3a, the rotor core 10 has a part directly mounted on the rotor shaft 2 ( Figure 1 The rotor core 10 has an inner core 12 and an outer core 11 arranged radially outward therefrom. That is, the rotor core 10 has an inner core 12 and an outer core 11 of the same number as the magnetic pole portions 3a.

[0033] The outer core 11 is fan-shaped and extends radially outward. In each magnetic pole portion 3a, the inner core 12 has a fan-shaped recess in a corresponding manner.

[0034] In each magnetic pole section 3a, the inner iron core 12 and the outer iron core 11 form two magnet receiving holes 15, each for receiving two permanent magnets 3. An outer space 16 is formed radially outward of the magnet receiving hole 15, communicating with the gap 5 on the outer side of the rotor iron core 10. Furthermore, a filling member 18 is filled in the space containing the magnet receiving hole 15 between the inner iron core 12 and the outer iron core 11. Here, the filling member 18 is, for example, a thermosetting resin. The filling member 18 fills the entire magnet receiving hole 15, or a portion radially inward of it, and the space radially inward of the magnet receiving hole 15.

[0035] The inner core 12 and the outer core 11 have engaging portions 14 on their radially inner sides, which engage with each other via a filling member 18. The outer core 11 has an outer core extension 11a extending radially inward, the radially innermost part of which connects to two outer core engaging portions 11b formed in a circumferentially extending manner. Additionally, the inner core 12 has an inner core engaging portion 12a arranged radially outward from each of the outer core engaging portions 11b.

[0036] A filling member 18 is provided between the two outer core engagement portions 11b and the two inner core engagement portions 12a. The two outer core engagement portions 11b, the two inner core engagement portions 12a, and the filling member 18 between them form an engagement portion 14. The engagement portion 14 prevents the outer cores 11 from moving radially outward due to centrifugal force, and has the function of preventing the outer cores 11 from falling off.

[0037] Two positioning inner bridges 21 are provided between the inner circumferential surface of the outer core engaging part 11b of the outer core 11 and the inner core 12 opposite thereto.

[0038] The inner positioning bridge 21 is not a reinforcement to resist the centrifugal force applied to the outer iron core 11 and the permanent magnet 3. In this regard, strength is ensured by integrating the outer iron core 11 with the inner iron core 12 using the engaging portion 14 and the filling member 18. The inner positioning bridge 21, as the positioning member 20, only needs to have the strength required for its positioning function to maintain the relative positional relationship between the inner iron core 12 and each of the outer iron cores 11 during the assembly of the rotor iron core 10. That is, from the viewpoint of suppressing the increase of leakage flux, it is preferable to have the narrowest possible width, provided it has the width required for the positioning function.

[0039] In the embedded magnet rotor 30 of this embodiment, configured as described above, the inner iron core 12 and each outer iron core 11 are engaged by an inner bridge 21 for positioning via each engaging portion 14. Therefore, even during the assembly of the rotor core 10, the relative positional relationship between the inner iron core 12 and each outer iron core 11 is maintained, and they do not shift relative to each other. That is, each engaging portion 14 has a positioning function. By suppressing deviations in the relative positions between the outer iron core 11 and the inner iron core 12, deviations in torque performance can be suppressed, thereby improving torque performance.

[0040] In addition, the inner bridge 21 for positioning is as narrow as possible while ensuring the width required for the positioning function, so the increase in leakage flux is also suppressed to a minimum.

[0041] [Second Implementation] Figure 4 This is a partial cross-sectional view showing the embedded magnet rotor 30a according to the second embodiment. This embodiment is a variation of the first embodiment, with a difference in part of the structure of the engaging portion 14. Otherwise, it is the same as the first embodiment.

[0042] Specifically, there are two outer core extensions 11a in the circumferential direction, with an extension barrier 11c formed between them. As a result, the rigidity of the root of the fan-shaped outer core 11 can be improved. Furthermore, while maintaining the rigidity value at the level of a single extension, the combined width of the two outer core extensions 11a in this embodiment can be smaller than the width of the outer core extensions 11a in the first embodiment. As a result, the width of the magnetic circuit for leakage flux can be reduced, thus reducing leakage flux.

[0043] [Third Implementation Method] Figure 5 This is a partial cross-sectional view showing the embedded magnet rotor 30b according to the third embodiment. This embodiment is a variation of the first embodiment. The positioning member 20 differs from the first embodiment in this embodiment. Otherwise, it is the same as the first embodiment.

[0044] In this embodiment, a positioning outer bridge 22 is provided instead of the positioning inner bridge 21 in the first embodiment as the positioning component 20.

[0045] The positioning outer peripheral bridge 22 is configured to span the outer space 16 adjacent to the radially outer side of each magnet receiving hole 15 and communicate with the gap portion 5. In other words, the positioning outer peripheral bridge 22 is configured to connect the outer peripheral portion of the outer iron core 11 with the outer peripheral portion of the inner iron core 12.

[0046] The positioning outer peripheral bridge 22 of the positioning member 20 is not a reinforcing member to resist the bending force applied to the outer core 11. In this regard, strength is ensured by integrating the outer core 11 with the inner core 12 using the engaging portion 14 and the filling member 18. Similar to the positioning inner bridge 21 in the first embodiment, the positioning outer peripheral bridge 22 of the positioning member 20 only needs to have the strength required for its positioning function to maintain the relative positional relationship between the inner core 12 and each outer core 11 during the assembly of the rotor core 10. That is, from the viewpoint of suppressing the increase of leakage flux, it is preferable to have the narrowest possible width, provided it has the width required for the positioning function.

[0047] In the embedded magnet rotor 30b of this embodiment, configured as described above, the inner iron core 12 and each outer iron core 11 are engaged by the positioning peripheral bridge 22 of each engaging portion 14. Therefore, when assembling the rotor iron core 10, the relative positional relationship between the inner iron core 12 and each outer iron core 11 is maintained, and they do not shift relative to each other. By suppressing the deviation in the relative position between the outer iron core 11 and the inner iron core 12, the deviation in torque performance can be suppressed, thereby improving torque performance.

[0048] In addition, the peripheral bridge 22 for positioning is as narrow as possible while ensuring the width required for the positioning function, so the increase in leakage flux is also suppressed to a minimum.

[0049] According to the described embodiments, an embedded magnet rotor and a rotary motor capable of positioning the outer iron core 11 and the inner iron core 12 can be provided.

[0050] [Other Implementation Methods] The embodiments of the present invention have been described above, but these embodiments are provided as examples and are not intended to limit the scope of the invention. Furthermore, features of each embodiment can be combined. For example, features of the second embodiment and features of the third embodiment can be combined. Moreover, the embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The embodiments and their variations are included within the scope and spirit of the invention, and also within the scope of the invention described in the patent claims and its equivalents.

[0051] Explanation of reference numerals in the attached figures 1… Embedded magnet rotor, 2… Rotor shaft, 3… Permanent magnet, 3a… Magnetic pole section, 5… Gap section, 10… Rotor core, 11… Outer core, 11a… Outer core extension, 11b… Outer core engaging section, 11c… Extension barrier, 12… Inner core, 12a… Inner core engaging section, 13… Outer barrier, 14… Engaging section, 15… Magnet storage hole, 16… Outer space, 18… Filling component, 20… Positioning component, 21… Positioning outer peripheral 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… Rotary motor.

Claims

1. A rotor with embedded magnets, comprising: The rotor shaft extends along the direction of rotation. The rotor core is mounted on the outer periphery of the rotor shaft; and Permanent magnets are disposed within the rotor core, and are arranged in one or more pairs around each magnetic pole in a circumferential manner. The embedded magnet rotor is characterized in that... The rotor core comprises: The inner iron core is installed on the outer periphery of the rotor shaft; The fan-shaped outer iron core is arranged radially outside the inner iron core in each of the magnetic pole portions; A filling component, filling the space between the inner core and the outer core; and The positioning component is capable of maintaining the relative positions of the inner iron core and each of the outer iron cores. 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 innermost radial part of the outer core.

2. The embedded magnet rotor according to claim 1, characterized in that, Each of the outer cores has two outer core engaging portions formed in a circumferentially extending manner at its innermost radial position. The inner core has an inner core engagement portion arranged radially outward from each outer core engagement portion. The positioning component has at least one positioning inner bridge that connects each of the outer core engagement portions to the inner core engagement portions.

3. The embedded magnet rotor according to claim 2, characterized in that, The outer core has two outer core extensions that are connected to and parallel to each other and are engaged with the outer core engagement portion.

4. The embedded magnet rotor according to claim 1, characterized in that, The positioning component has a positioning outer peripheral bridge that connects the outer periphery of the outer core to the circumferentially adjacent portion of the outer periphery of the inner core.

5. A rotary electric motor, characterized in that, have: Embedded magnet rotor as described in any one of claims 1 to 4; The stator is disposed radially outside the embedded magnet rotor; and The bearing supports the rotor shaft so that it can rotate.

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