WO2017046950A1

WO2017046950A1 - Rotary electric machine

Info

Publication number: WO2017046950A1
Application number: PCT/JP2015/076727
Authority: WO
Inventors: 昭仁豊田; 真一郎向; 広一福村; 宏之前澤; 大戸　基道
Original assignee: 株式会社安川電機
Priority date: 2015-09-18
Filing date: 2015-09-18
Publication date: 2017-03-23

Abstract

A motor 1 is provided with: a stator 20 that generates a rotating magnetic field; and a rotor 30 that is disposed at the inner circumference side of the stator 20 and that rotates according to the rotating magnetic field. The rotor 30 includes a plurality of permanent magnets 35 aligned in the rotation direction of the rotor 30, a rotor core 36 interposed among the permanent magnets 35, and a plate 38 that overlaps the rotor core 36 along a central axis Ax1 and that lies on the outer perimeter of the permanent magnets 35.

Description

Rotating electric machine

This disclosure relates to a rotating electrical machine.

Patent Document 1 discloses a rotating electrical machine that includes a stator that generates a rotating magnetic field, and a rotor that is arranged on the inner peripheral side of the stator and rotates according to the rotating magnetic field. The rotor has a plurality of permanent magnets arranged in the rotation direction of the rotor, and a rotor core interposed between the permanent magnets.

JP 2013-34325 A

This disclosure aims to provide a rotating electric machine with higher output.

A rotating electrical machine according to an embodiment of the present disclosure includes a stator that generates a rotating magnetic field, and a rotor that is disposed on the inner peripheral side of the stator and rotates in accordance with the rotating magnetic field, and the rotor is arranged in the rotation direction of the rotor. A plurality of permanent magnets, a rotor core interposed between the permanent magnets, and a plate configured to overlap the rotor core along the rotation axis of the rotor and to be applied to the outer periphery of the permanent magnet.

According to the present disclosure, it is possible to provide a rotating electric machine with higher output.

It is sectional drawing in the cross section perpendicular | vertical to the central axis of the rotary electric machine which concerns on embodiment. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. It is sectional drawing in the cross section perpendicular | vertical to a central axis which shows the example of a stator core and a coil expanding. It is sectional drawing which follows the center axis line which expands and shows the example of a stator core and a coil. It is a schematic diagram which shows the manufacturing process of a coil. It is sectional drawing in a cross section perpendicular | vertical to a center axis line which expands and shows another example of a stator core and a coil. It is a perspective view of a rotor. FIG. 3 is a cross-sectional view of the rotor taken along line VIII-VIII in FIG. 2. FIG. 3 is an end view of the rotor taken along line IX-IX in FIG. 2. It is sectional drawing of the rotary electric machine in alignment with a central axis which shows another example of arrangement | positioning of a plate. It is a figure which shows typically the magnetic flux in a rotary electric machine.

Hereinafter, embodiments will be described in detail with reference to the drawings. In the description, the same elements or elements having the same functions are denoted by the same reference numerals, and redundant description is omitted.

The motor (rotating electric machine) 1 according to the present embodiment is, for example, a synchronous motor with a built-in permanent magnet. The motor 1 can be used as a power source of an electric device, for example.

As shown in FIGS. 1 and 2, the motor 1 includes a motor case 10, a stator 20, and a rotor 30.

[Motor case]
The motor case 10 houses the stator 20 and the rotor 30. For example, the motor case 10 includes a cylindrical frame 11, and a first bracket 12 and a second bracket 13 that close both ends of the frame 11. The first bracket 12 is attached to a motor mount to be driven.

[Stator]
The stator 20 generates a rotating magnetic field. The stator 20 includes, for example, a plurality of coils 21 and a stator core 24.

(Stator core)
Stator core 24 includes a yoke 24a and a plurality of teeth 24b. The yoke 24a is annular, and is fixed to the inner surface of the frame 11 with its center axis Ax1 being along the center axis of the frame 11. The plurality of teeth 24b are disposed so as to surround the central axis Ax1 of the yoke 24a, and project from the inner peripheral surface of the yoke 24a toward the central axis Ax1. The yoke 24a and the teeth 24b may be a laminate of electromagnetic steel plates or may be a compression-molded soft magnetic composite material (SMC).

The stator core 24 may be divided into a plurality of blocks 25 surrounding the central axis Ax1, and the teeth 24b may be provided for each block 25. Each of the teeth 24 b may be located at the center of the block 25 in the circumferential direction of the stator core 24.

(coil)
The plurality of coils 21 are respectively attached to the plurality of teeth 24b. The strands of the coil 21 are accommodated between the adjacent teeth 24b in a state of surrounding the teeth 24b. That is, between the teeth 24b is a slot 26 for accommodating the coil 21, and the coil 21 is wound around the tooth 24b. As described above, the stator core 24 includes the slot 26, and the coil 21 is disposed in the slot 26. For example, the coil 21 may be integrated with the stator core 24 by molding using a resin material.

Driving power (for example, three-phase AC power) is supplied to the plurality of coils 21 via the connection part 22. The plurality of coils 21 generate a rotating magnetic field around the central axis Ax1 according to the supply of driving power. The connection part 22 is provided between the coil 21 and the 2nd bracket 13, for example.

(Insulator)
As shown in FIG. 3, the stator 20 may further include an insulator 27. The insulator 27 has electrical insulation and is interposed between the stator core 24 and the coil 21. The insulator 27 is, for example, a resinous thin member. For example, the insulator 27 includes a cylindrical portion 27a mounted around the teeth 24b, and a flange portion 27b projecting from the end of the cylindrical portion 27a to the outer peripheral side on the yoke 24a side. The shape of the insulator 27 can be appropriately changed according to the shape of the stator core 24. Further, the thickness and material of the insulator 27 can be appropriately set according to the electrical insulation performance to be secured between the coil 21 and the stator core 24. The insulator 27 may be integrated with the coil 21 and the stator core 24 by molding using, for example, a resin material.

(Coil forming surface)
The coil 21 may have a molding surface 21 a that follows the surface 24 c of the stator core 24. As shown in FIG. 4, the coil 21 may further include a molding surface 21 b that follows the inner surface (the surface on the second bracket 13 side) 12 a of the first bracket 12.

The

molding surfaces

21a and 21b are formed by press-molding the coil 21, for example. For example, as shown in FIG. 5, the coil 21 is press-molded by compressing a coil 21 formed by winding an element wire 51 with a molding die (for example, a die) 50 as indicated by an arrow A. It is formed by pressing the inner surface 50 a against the outer surface of the coil 21. For this reason, the

molding surfaces

21a and 21b which respectively follow the said surface 24c and the inner surface 12a are formed by making the inner surface shape of the shaping | molding die 50 correspond with the said surface 24c and the inner surface 12a.

By forming the molding surface 21a on the coil 21, the gap between the coil 21 and the stator core 24 can be reduced, and the cross-sectional area of the coil 21 can be enlarged within a limited space. By forming the molding surface 21b on the coil 21, the gap between the coil 21 and the first bracket 12 can be reduced, and the cross-sectional area of the coil 21 can be further enlarged. By press molding when forming the

molding surfaces

21a and 21b, the strands 51 come close to each other, and the space factor of the coil 21 (the ratio of the strands 51 in the cross section of the coil 21) is improved. By increasing the cross-sectional area of the coil 21 and improving the space factor, for example, the wire 51 is thickened without changing the number of turns of the coil 21, and heat generation due to the electric resistance of the wire 51 is suppressed. Temperature rise can be suppressed. By reducing the gap between the coil 21 and the stator core 24 and reducing the gap between the coil 21 and the first bracket 12, an improvement in heat dissipation from the coil 21 is also expected. Thereby, the temperature rise of the coil 21 can further be suppressed. By suppressing the temperature rise of the coil 21, the input current to the coil 21 can be increased without increasing the motor 1 and the output of the motor 1 can be improved.

At least one of the surface 24c of the stator core 24 and the molding surface 21a of the coil 21 may be partially formed with a receding surface 23 away from the other of the surface 24c and the molding surface 21a. For example, the receding surface 23 may be formed on the molding surface 21a. In this case, the receding surface 23 is formed so as to be away from the surface 24 c of the stator core 24. The receding surface 23 of the molding surface 21a can be formed by the press molding described above.

As shown in FIG. 6, the receding surface 23 may be provided on the surface 24 c of the stator core 24. In this case, the receding surface 23 is provided so as to be away from the molding surface 21 a of the coil 21. Below, the case where the receding surface 23 is formed in the molding surface 21a is demonstrated in detail.

3 and 4, the receding surface 23 may be provided at a position corresponding to the edge of the insulator 27. For example, the receding surface 23 may be provided at a position corresponding to at least a part of the peripheral edge portion 27c at the tip (end on the central axis Ax1 side) of the cylindrical portion 27a. In addition, the position corresponding to the peripheral part 27c means the position where the space between the receding surface 23 and the insulator 27 is formed in the peripheral part 27c. The same applies to the following. The receding surface 23 may be provided at a position corresponding to at least a part of the peripheral edge portion 27d of the flange portion 27b.

The receding surface 23 may extend along the central axis Ax1. For example, the receding surface 23 may be provided in a portion along the central axis Ax1 in the

peripheral portions

27c and 27d. As shown in FIG.3 and FIG.4, the receding surface 23 may be provided over the perimeter of the

peripheral parts

27c and 27d.

The space S formed between the receding surface 23 and the surface 24c of the stator core 24 may be filled with resin. That is, the stator 20 may further include a resin portion 28 formed between the stator core 24 and the coil 21 at a position corresponding to the receding surface 23. This resin may be the resin for molding described above. The space S may be a cavity that is not filled with resin.

The size of the space S between the receding surface 23 and the stator core 24 is preferably sufficiently smaller than the cross-sectional area of the coil 21 in the direction perpendicular to the central axis Ax1. The size of the space S is determined according to the following two conditions, for example. The first condition is that the creepage distance between the coil 21 and the stator core 24 can be secured to a degree sufficient to maintain the electrical insulation between the coil 21 and the stator core 24. The second condition is that the space S can be filled with resin in the molding.

[Rotor]
FIG. 7 is a perspective view of the rotor 30. The rotor 30 is disposed on the inner peripheral side of the stator 20 and rotates according to a rotating magnetic field generated by the stator 20. For example, the rotor 30 includes a shaft 31 extending along the central axis Ax1, a plurality (ten in this embodiment) of permanent magnets 35, a rotor core 36, and a plate 38.

(shaft)
The shaft 31 is disposed along the central axis Ax1 of the stator 20. The shaft 31 is rotatably held around the central axis Ax1 by the first bearing 14 provided on the first bracket 12 and the second bearing 15 provided on the second bracket 13. Thereby, the rotor 30 is rotatable around the central axis Ax1. That is, the central axis Ax1 is the rotation axis of the rotor 30. Examples of the first bearing 14 and the second bearing 15 include a rolling bearing and a sliding bearing.

The one end 31 a of the shaft 31 penetrates the first bracket 12. The one end 31 a functions as an output shaft of the motor 1. The other end 31 b of the shaft 31 passes through the second bracket 13. The other end 31b can be used for detecting a rotation angle or the like. As a specific example, the other end 31b may be connected to a rotary shaft of a rotary encoder 41 provided outside the second bracket 13 (on the opposite side of the first bracket 12).

(Permanent magnet and rotor core)
The plurality of permanent magnets 35 are arranged on the outer periphery of the shaft 31 so as to be aligned in the rotational direction of the rotor 30. In other words, the plurality of permanent magnets 35 are arranged so as to surround the shaft 31. The permanent magnets 35 each have a flat plate shape extending along the central axis Ax1, and are arranged radially when viewed from the extended line of the central axis Ax1.

The permanent magnet 35 is arranged so that its magnetization direction is along the rotation direction of the rotor 30. That is, the N pole and S pole of the permanent magnet 35 are arranged along the rotation direction of the rotor 30. Further, the magnetization directions of the permanent magnets 35 adjacent to each other in the rotation direction of the rotor 30 are opposite to each other. That is, between the adjacent permanent magnets 35, the N poles or the S poles face each other.

The rotor core 36 is interposed between the permanent magnets 35. The rotor core 36 is fixed to the shaft 31 and guides the magnetic flux of the permanent magnet 35 to the rotor core 36 side. As an example, the rotor core 36 may include a plurality of (10 in this embodiment) core blocks 37 that are alternately arranged with the permanent magnets 35 in the rotation direction of the rotor 30. The plurality of core blocks 37 may be separated from each other, and may be fixed to the outer periphery of the shaft 31.

With such a configuration, the permanent magnet 35 and the rotor core 36 form a field in which magnetic poles (N poles) that emit magnetic flux to the stator 20 side and magnetic poles (S pole) that receive magnetic flux from the stator 20 side are alternately arranged. .

The rotor core 36 is made of a magnetic material such as a soft magnetic material. The rotor core 36 may be a laminated body of electromagnetic steel plates. For example, the rotor core 36 may be configured by stacking electromagnetic steel plates in a direction along the central axis Ax1 and integrating them by caulking in the caulking portion 36a (see FIG. 8). The method for fixing the electromagnetic steel sheets is not limited to caulking. For example, the electromagnetic steel plates may be fixed to each other by passing a pin along the central axis Ax1 through each electromagnetic steel plate. When the rotor core 36 is divided into a plurality of core blocks 37, each of the core blocks 37 is configured, for example, by stacking sector-shaped electromagnetic steel plates in a direction along the central axis Ax1.

The rotor core 36 is configured not to hang on the outer periphery of the permanent magnet 35 (side surface 35a on the stator 20 side). In other words, the rotor core 36 is configured so as not to overlap the permanent magnet 35 in the radial direction of the rotor 30 on the outer peripheral side of the permanent magnet 35. For example, as shown in FIG. 8, the rotor core 36 opens toward the stator 20 at an interval equal to or greater than the thickness of the permanent magnet 35 in the rotation direction of the rotor 30. That is, the space between the core blocks 37 is open to the stator 20 side at an interval equal to or greater than the thickness of the permanent magnet 35 in the rotation direction of the rotor 30. Thereby, the outer periphery of the permanent magnet 35 is exposed to the stator 20 side without being covered by the rotor core 36. The rotor core 36 may be hooked on a part of the side surface 35a of the permanent magnet 35 on the stator 20 side, and only a part of the side surface 35a may be exposed on the stator 20 side.

The rotor core 36 may be configured not to be applied to the inner periphery (side surface 35b on the central axis Ax1 side) of the permanent magnet 35. In other words, the rotor core 36 may be configured so as not to overlap the permanent magnet 35 in the radial direction of the rotor 30 on the inner peripheral side of the permanent magnet 35. For example, the rotor core 36 opens to the shaft 31 side at equal intervals or more with respect to the thickness of the permanent magnet 35 in the rotation direction of the rotor 30. That is, the space between the core blocks 37 is open toward the shaft 31 at an interval equal to or greater than the thickness of the permanent magnet 35 in the rotation direction of the rotor 30. Thereby, the inner periphery of the permanent magnet 35 is exposed to the shaft 31 side without being covered by the rotor core 36. The rotor core 36 may be hooked on a part of the side surface 35b on the central axis Ax1 side of the permanent magnet 35, and only a part of the side surface 35b may be exposed on the central axis Ax1 side.

In addition, when the rotor core 36 is divided into a plurality of core blocks 37, it is possible to easily configure a state in which the rotor core 36 does not reach both the outer periphery and the inner periphery of the permanent magnet 35.

(Low magnetic part)
At least a portion 31 c of the shaft 31 fixed to the rotor core 36 may be made of a low magnetic material having a lower magnetic permeability than the magnetic permeability of the rotor core 36. The relative magnetic permeability of the low magnetic material is, for example, 500 or less, preferably 100 or less, and more preferably 50 or less. Examples of the low magnetic material include a nonmagnetic stainless material. Hereinafter, the portion 31c is referred to as a “low magnetic portion 31c”.

The low magnetic portion 31c may have at least one convex portion 31d fitted into the rotor core 36. In this case, the rotor core 36 is provided with a concave portion 36b having a shape corresponding to the convex portion 31d, and the convex portion 31d is fitted into the concave portion 36b. The convex portion 31d extends, for example, along the central axis Ax1. The convex portion 31d may be disposed between the adjacent permanent magnets 35. The convex portion 31d may have a shape that expands toward the outer peripheral side. The low magnetic portion 31 c may have a plurality of convex portions 31 d arranged alternately with the permanent magnet 35 in the rotation direction of the rotor 30. In addition, when the top part of the convex part 31d is made into the reference | standard, between the convex parts 31d becomes the recessed part 31e. That is, the shaft 31 having the convex portion 31d is synonymous with the shaft 31 having the concave portion 31e.

The portions other than the low magnetic portion 31 c of the shaft 31 may be made of the above-described low magnetic material, or may be made of the same soft magnetic material as the rotor core 36.

The shaft 31 may be divided into a shaft body 32 and a low magnetic pipe 33 attached to the outer periphery of the shaft body 32. The shaft body 32 and the low magnetic pipe 33 are fixed to each other, for example, by shrink fitting or press fitting. The constituent material of the shaft body 32 can be appropriately selected from the viewpoint of strength and the like. The low magnetic pipe 33 is made of the above-described low magnetic material, and includes the low magnetic portion 31c on the outer periphery thereof. That is, the rotor core 36 is fixed to the outer periphery of the low magnetic pipe 33.

(plate)
The plate 38 is disposed so as to overlap the rotor core 36 along the central axis Ax1. As shown in FIGS. 2, 7, and 9, the plate 38 is configured to be engaged with the outer periphery of the permanent magnet 35 (the side surface 35 a on the stator 20 side). With this configuration, the plate 38 restricts the movement of the permanent magnet 35 in the radial direction around the central axis Ax1, and fixes the permanent magnet 35. The plate 38 may be configured to be applied to the inner periphery (side surface 35b on the side of the central axis Ax1) of the permanent magnet 35.

For example, the plate 38 has a circular outer shape concentric with the shaft 31. The plate 38 has a hole 38a at the center thereof, and further includes a plurality of holes 38b surrounding the hole 38a. The shaft 31 is passed through the hole 38a, and the plurality of permanent magnets 35 are passed through the plurality of holes 38b. With this configuration, a portion adjacent to the stator 20 side with respect to the hole 38b is hooked on the outer periphery of the permanent magnet 35, and a portion adjacent to the center axis Ax1 side with respect to the hole 38b is hooked on the inner periphery of the permanent magnet 35.

The outer diameter of the plate 38 may be equal to the outer diameter of the rotor core 36. Accordingly, the outer periphery of the permanent magnet 35 may be positioned closer to the central axis Ax1 than the outer periphery of the rotor core 36. The inner diameter of the plate 38 may be equal to the inner diameter of the rotor core 36. Accordingly, the inner periphery of the permanent magnet 35 may be located closer to the stator 20 than the outer periphery of the rotor core 36. That is, the inner periphery of the permanent magnet 35 may be separated from the outer periphery of the shaft 31.

The rotor 30 may have a plurality of plates 38. In this case, the plurality of plates 38 may be arranged so as to sandwich the rotor core 36 in the direction in which the central axis Ax1 extends. The plurality of plates 38 may include two plates 38 disposed at both ends of the rotor core 36 in the direction in which the central axis Ax1 extends. The plate 38 may be disposed at a position that does not overlap the teeth 24b in the direction along the central axis Ax1 (see FIG. 2). Note that the rotor 30 does not necessarily have a plurality of plates 38. Further, the plate 38 may be disposed at any position between both ends of the rotor core 36 instead of both ends of the rotor core 36 in the direction in which the central axis Ax1 extends. The number of plates 38 may be one or plural. As a modification of the example shown in FIG. 2, as shown in FIG. 10, three plates 38 may be provided at both ends and the center of the rotor core 36 in the direction along the central axis Ax <b> 1.

The material constituting the plate 38 may have a lower magnetic permeability than the material constituting the rotor core 36. For example, the plate 38 may be made of the above-described low magnetic material.

As shown in FIG. 9, the convex portion 31 d may be fitted into the plate 38 in addition to the rotor core 36. In this case, the plate 38 is provided with a concave portion 38c having a shape corresponding to the convex portion 31d, and the convex portion 31d is fitted into the concave portion 38c.

When the rotor core 36 is divided into a plurality of core blocks 37, the core blocks 37 may be integrated via a plate 38. In other words, the plurality of core blocks 37 may be grouped together by being attached to the plate 38.

The plate 38 may be fixed to the rotor core 36 by performing a caulking process in the caulking portion 38d corresponding to the caulking portion 36a, for example. When the electromagnetic steel plates constituting the rotor core 36 are fixed by pins, the plate 38 may be fixed to the rotor core 36 by allowing the pins to penetrate the plate 38.

(Magnetic path formed by the rotor core)
In the rotor 30 configured as described above, as shown in FIG. 11, the magnetic flux from the permanent magnet 35 is guided to the magnetic path R <b> 1 toward the stator 20 by the rotor core 36 and is linked to the coil 21. As a result, this magnetic flux interacts with the rotating magnetic field generated by the coil 21 to generate a rotational torque around the central axis Ax1, and the rotor 30 rotates. As described above, when the rotor core 36 is configured not to hang on the outer periphery of the permanent magnet 35, the magnetic flux passing through the magnetic path R <b> 2 that circulates on the outer periphery side of the permanent magnet 35 without passing through the stator 20 is reduced. Moreover, when the low magnetic part 31c is formed in the outer periphery of the shaft 31, the magnetic flux which passes along the magnetic path R3 which circulates through the inner peripheral side of the permanent magnet 35 without passing through the stator 20 is reduced. Further, when the rotor core 36 is configured not to be applied to the inner periphery of the permanent magnet 35, the magnetic flux passing through the magnetic path R3 is further reduced. These contribute to the magnetic flux concentration on the magnetic path R1 toward the stator 20 side. Due to the magnetic flux concentration on the magnetic path R1, the output of the motor 1 can be further improved.

[Effect of this embodiment]
Hereinafter, the operation and effect of the motor 1 according to the embodiment will be described. The motor 1 includes a stator 20 that generates a rotating magnetic field, and a rotor 30 that is arranged on the inner peripheral side of the stator 20 and rotates in accordance with the rotating magnetic field. A magnet 35, a rotor core 36 interposed between the permanent magnets 35, a plate 38 configured to overlap the rotor core 36 along the rotation axis (center axis Ax 1) of the rotor 30 and to be applied to the outer periphery of the permanent magnet 35, . According to the motor 1, the permanent magnet 35 can be fixed by the plate 38 without covering the permanent magnet 35 with a fixing claw or the like protruding from the rotor core 36 on the outer peripheral side of the permanent magnet 35. Therefore, the magnetic flux not linked to the coil 21 (for example, the magnetic flux passing through the magnetic path R2 in FIG. 11) is reduced, and the magnetic flux from the permanent magnet 35 is efficiently guided to the stator 20 side (concentrated on the magnetic path R1 in FIG. 11). ), The output of the motor 1 can be improved.

The rotor core 36 is a laminated body of electromagnetic steel plates, and the plate 38 may be made of an electromagnetic steel plate common to the rotor core 36. In this case, for example, since both the rotor core 36 and the plate 38 can be configured in a series of processes in which electromagnetic steel sheets are punched into a predetermined shape and stacked, manufacturing of the motor 1 is facilitated.

The rotor core 36 is composed of a plurality of core blocks 37 alternately arranged with the permanent magnets 35 in the rotation direction of the rotor 30, and the core blocks 37 may be integrated with each other via a plate 38. In this case, as compared with the case where the entire rotor core 36 is integrated, the rotor core 36 is divided at a position corresponding to the permanent magnet 35, and therefore the magnetic flux circulating without interlinking with the stator 20 (the magnetic field in FIG. 11). (Magnetic flux passing through the paths R2 and R3) can be more reliably suppressed. Therefore, the magnetic flux from the permanent magnet 35 can be more efficiently guided to the stator 20 side (concentrated on the magnetic path R1 in FIG. 11), and the output of the motor 1 can be improved. Even if the core blocks 37 are separated from each other, they are integrated through the plate 38, so that they are easy to handle in the manufacturing process.

The rotor 30 includes a plurality of plates 38, and the plurality of plates 38 may be disposed so as to sandwich the rotor core 36 in the direction in which the central axis Ax1 extends. In this case, since the plate 38 holds the outer peripheral side of the permanent magnet 35 at both ends of the rotor core 36 in the direction in which the central axis Ax1 extends, the permanent magnet 35 can be held in the rotor 30 more reliably.

The plurality of plates 38 may include two plates 38 disposed at both ends of the rotor core 36 in the direction in which the central axis Ax1 extends. In this case, since the permanent magnet 35 is held at both ends of the rotor core 36, the permanent magnet 35 can be held more firmly.

The stator 20 includes a coil 21 that generates a rotating magnetic field and a stator core 24 that includes a tooth 24b around which the coil 21 is wound, and the plate 38 is in a position that does not overlap with the tooth 24b in the direction along the central axis Ax1. It may be arranged. In this case, since the magnetic flux is prevented from leaking from the permanent magnet 35 to the teeth 24b via the plate 38, the magnetic flux from the permanent magnet 35 can be guided to the stator 20 more efficiently.

The material constituting the plate 38 may have a lower magnetic permeability than the material constituting the rotor core 36. In this case, since the magnetic flux is prevented from leaking from the permanent magnet 35 to the teeth 24b via the plate 38, the magnetic flux from the permanent magnet 35 can be guided to the stator 20 more efficiently.

The rotor core 36 may be arranged so as not to hang on the outer periphery of the permanent magnet 35. In this case, the generation of the magnetic flux circulating around the outer periphery of the permanent magnet 35 without passing through the stator core 24 (the magnetic flux passing through the magnetic path R2 in FIG. 11) is suppressed, and the magnetic flux from the permanent magnet 35 is guided to the stator 20 more efficiently. be able to.

The plate 38 may be configured to be applied to the inner periphery of the permanent magnet 35. In this case, generation of magnetic flux circulating through the inner peripheral side of the permanent magnet 35 without passing through the stator core 24 (magnetic flux passing through the magnetic path R3 in FIG. 11) is suppressed, and the magnetic flux from the permanent magnet 35 is more efficiently transferred to the stator 20. Can lead.

The rotor 30 further includes a shaft 31 that is disposed on the inner peripheral side of the rotor core 36 and is fixed to the rotor core 36. At least a portion (low magnetic portion 31 c) of the shaft 31 that is fixed to the rotor core 36 is the rotor core 36. You may be comprised with the low magnetic material with low magnetic permeability compared with this material. In this case, the leakage of the magnetic flux to the inner peripheral side such as the magnetic flux passing through the magnetic path R3 in FIG. Therefore, the magnetic flux can be efficiently linked to the stator 20 and the output of the motor 1 can be improved.

The low magnetic part 31c may have a convex part 31d fitted into the rotor core 36 and the plate 38. In this case, since the shaft 31 can be inserted into the rotor core 36 and the plate 38 along the central axis Ax1 in a state where the rotor core 36 and the plate 38 are integrated, the manufacture of the motor 1 is facilitated.

As mentioned above, although embodiment was described, this indication is not necessarily restricted to embodiment mentioned above, A various change is possible in the range which does not deviate from the gist.

This disclosure can be used for rotating electrical machines.

DESCRIPTION OF SYMBOLS 1 ... Motor (rotary electric machine), 20 ... Stator, 21 ... Coil, 24 ... Stator core, 24b ... Teeth, 30 ... Rotor, 31 ... Shaft, 31d ... Convex part, 35 ... Permanent magnet, 36 ... Rotor core, 37 ... Core block 38 ... plate, Ax1 ... center axis (rotary axis).

Claims

A stator that generates a rotating magnetic field, and a rotor that is arranged on the inner peripheral side of the stator and rotates according to the rotating magnetic field,
The rotor is
A plurality of permanent magnets arranged in the rotational direction of the rotor;
A rotor core interposed between the permanent magnets;
A rotating electric machine comprising: a plate configured to overlap the rotor core along a rotation axis of the rotor and to be applied to an outer periphery of the permanent magnet.
The rotor core is a laminate of electromagnetic steel sheets,
The rotating electrical machine according to claim 1, wherein the plate is made of an electromagnetic steel plate common to the rotor core.
The rotor core is composed of a plurality of core blocks arranged alternately with the permanent magnet in the rotation direction,
The rotating electrical machine according to claim 1 or 2, wherein the core blocks are integrated with each other via the plate.
The rotor has a plurality of the plates,
The rotating electrical machine according to any one of claims 1 to 3, wherein the plurality of plates are arranged so as to sandwich the rotor core in a direction in which the rotating shaft extends.
The rotating electric machine according to claim 4, wherein the plurality of plates include two plates arranged at both ends of the rotor core in a direction in which the rotation shaft extends.
The stator has a coil that generates the rotating magnetic field, and a stator core that includes teeth around which the coil is wound,
The rotating electrical machine according to claim 5, wherein the plate is disposed at a position that does not overlap the teeth in a direction along the rotation axis.
The rotating electrical machine according to claim 1, wherein a material constituting the plate has a lower magnetic permeability than a material constituting the rotor core.
The rotating electrical machine according to any one of claims 1 to 7, wherein the rotor core is disposed so as not to be hung on an outer periphery of the permanent magnet.
The rotating electrical machine according to any one of claims 1 to 8, wherein the plate is configured to be applied to an inner periphery of the permanent magnet.
The rotor further includes a shaft disposed on the inner peripheral side of the rotor core and fixed to the rotor core,
The rotating electrical machine according to any one of claims 1 to 9, wherein at least a portion of the shaft fixed to the rotor core is made of a low magnetic material having a lower magnetic permeability than a material of the rotor core.
11. The rotating electrical machine according to claim 10, wherein the portion of the shaft that is fixed to the rotor core has a convex portion that is fitted into the rotor core and the plate.