JP2016163462A - Permanent magnet motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet motor capable of securing a magnetic flux amount while preventing demagnetization of a permanent magnet.SOLUTION: A permanent magnet 450A1 is inserted into a magnet insertion hole 410A1 of a main magnetic pole section A of a rotor 400. A gap 442A1 is formed between an outer peripheral side end wall 454A1 of the permanent magnet 450A1 and an outer peripheral surface 400a of the rotor 400. The gap 442A1 is formed by a first portion opposed to the outer peripheral side end wall 454A1 of the permanent magnet 450A1 and a second portion extended from the first portion to a magnetic pole center direction of a main magnetic pole portion A. An angle θ formed by the permanent magnet 450A1 and an inner peripheral wall 415A1 of the second portion of the gap 442A1, a length N along an extending direction of an outer peripheral wall 411A1 when the inner peripheral wall 415A1 is projected to the outer peripheral wall 411A1 and a length L from a position where an end portion Q of the main magnetic pole portion center side of the inner peripheral wall 415A1 is projected to the outer peripheral wall 411A1 up to the outer peripheral side end wall 454A1 of the permanent magnet 450A1 are constituted so as to satisfy [38 degrees≤θ≤44 degrees] and [0.7≤(L/N)≤1.0].SELECTED DRAWING: Figure 3

Description

  The present invention relates to a permanent magnet motor, and more particularly to a permanent magnet motor capable of ensuring a magnetic flux while preventing demagnetization of the permanent magnet.

A permanent magnet motor is used as an electric motor for driving a compressor, a vehicle, an in-vehicle device mounted on the vehicle, and the like provided in a refrigerator or an air conditioner. For example, the rotor includes a stator and a rotor, and the rotor includes main magnetic pole portions and auxiliary magnetic pole portions that are alternately arranged along the circumferential direction when viewed in a cross section perpendicular to the axial direction. A magnet insertion hole is formed, and a permanent magnet motor in which a permanent magnet is inserted into the magnet insertion hole (referred to as “permanent magnet embedded type motor”) is used. As the permanent magnet, a rare earth magnet is preferably used. Such a permanent magnet motor can utilize both magnet torque due to the magnetic flux of the permanent magnet and reluctance torque due to the saliency of the rotor.
Here, when the short-circuit magnetic flux flows through the rotor portion (iron core portion) between the outer peripheral side end wall portion of the permanent magnet and the outer peripheral surface of the rotor, the magnetic flux amount of the main magnetic flux decreases. Therefore, in such a permanent magnet motor, a gap is provided between the outer peripheral side end wall portion of the permanent magnet and the outer peripheral surface of the rotor.
Conventionally, in order to further reduce the amount of short-circuit magnetic flux and increase the amount of main magnetic flux, an air gap provided between the outer peripheral side wall of the permanent magnet and the outer peripheral surface of the rotor is extended toward the center of the main magnetic pole. An existing permanent magnet motor has been proposed (see Patent Document 1).

JP 2007-300796 A

In the permanent magnet motor disclosed in Patent Document 1, the amount of short-circuit magnetic flux is reduced by extending a gap provided between the outer peripheral side wall of the permanent magnet and the outer peripheral surface of the rotor in the center direction of the main magnetic pole. The amount of magnetic flux of the main magnetic flux is increased and reduced.
Here, when the main magnetic flux is concentrated on the outer peripheral side end portion (in the vicinity of the outer peripheral end wall portion) of the permanent magnet, the outer peripheral end portion of the permanent magnet is demagnetized, and the magnetic flux amount of the main magnetic flux is reduced. In order to prevent demagnetization of the permanent magnet, it is necessary to increase the thickness of the permanent magnet. If the permanent magnet is thickened, the amount of magnet usage increases, and the permanent magnet motor becomes expensive.
The present invention has been made in view of such a point, and an object of the present invention is to provide a permanent magnet motor that can secure a magnetic flux while preventing demagnetization of the permanent magnet.

The permanent magnet motor of the present invention includes a stator and a rotor that is rotatably disposed inside the stator via a gap (air gap). The rotor is viewed in a cross section perpendicular to the axial direction. It has main magnetic pole portions and auxiliary magnetic pole portions that are alternately arranged along the circumferential direction. A magnet insertion hole is formed in the main magnetic pole portion, and a permanent magnet is inserted in the magnet insertion hole.
The description “axial direction” represents the extending direction (longitudinal direction) of the rotating shaft in a state where the rotor is rotatably arranged with respect to the stator. As the permanent magnet, a rare earth magnet is typically used, but various permanent magnets such as a ferrite magnet can also be used. The number of magnet insertion holes formed in the main magnetic pole portion, the number of permanent magnets inserted into the magnet insertion holes, the cross-sectional shape, and the like can be variously changed within a range in which both magnet torque and reluctance torque can be used.
In the present invention, the magnet insertion hole has a magnet insertion portion formed by a first outer peripheral side wall portion and a first inner peripheral side wall portion disposed closer to the rotation center than the first outer peripheral side wall portion. Yes. Preferably, the first outer peripheral side wall portion and the first inner peripheral side wall portion are arranged in parallel (including “substantially parallel”).
The rotor has a gap between the outer peripheral side wall of the permanent magnet inserted into the magnet insertion hole and the outer peripheral surface of the rotor. The air gap has a first portion that faces the outer peripheral side end wall portion of the permanent magnet, and a second portion that extends from the first portion toward the center of the main magnetic pole portion. The second portion is formed by a second outer peripheral side wall portion and a second inner peripheral side wall portion that is disposed closer to the rotation center than the second outer peripheral side wall portion. Preferably, the second outer peripheral side wall and the second inner peripheral side wall are arranged in parallel (including “substantially parallel”). The air gap may be provided in the magnet insertion hole, or may be provided between the magnet insertion hole and the outer peripheral surface of the rotor.
Then, the angle θ formed by the first outer peripheral side wall and the second inner peripheral side wall, the extension of the first outer peripheral side wall when the second inner peripheral side wall is projected onto the first outer peripheral side wall. A length N along the current direction, and a length L from the position where the end of the second inner peripheral side wall on the main magnetic pole part center side is projected onto the first outer peripheral side wall to the outer peripheral side end wall of the permanent magnet Is configured to satisfy [38 degrees ≦ θ ≦ 44 degrees] and [0.7 ≦ (L / N) ≦ 1.0].
In the present invention, the configuration is such that [38 degrees ≦ θ ≦ 44 degrees] and [0.7 ≦ (L / N) ≦ 1.0] are satisfied, thereby reducing the outer peripheral side end of the permanent magnet. The magnetic flux amount of the main magnetic flux can be secured while preventing magnetism.
In a different form of the present invention, the width G of the gap between the inner peripheral surface of the stator and the outer peripheral surface of the rotor, the thickness H of the permanent magnet, the second outer peripheral side wall portion and the second inner peripheral side wall portion forming the air gap The wall spacing S is configured to satisfy [G ≦ S ≦ H].
In this embodiment, it is possible to prevent the short-circuit magnetic flux from flowing through the second portion of the gap by being configured to satisfy [G ≦ S]. Moreover, by being comprised so that [S <= H] may be satisfied, the length of a permanent magnet can be lengthened and the magnetic flux amount of a main magnetic flux can be ensured.
In another different embodiment of the present invention, [H ≦ L] is satisfied.
In this embodiment, the magnetic flux amount of the main magnetic flux can be secured while preventing demagnetization of the outer peripheral side end portion of the permanent magnet.
In another different embodiment of the present invention, the minimum value T between the gap and the outer peripheral surface of the rotor is configured to satisfy [0.4 mm ≦ T ≦ 1.0 mm].
In this embodiment, the strength of the rotor against centrifugal force can be ensured and a short circuit of the main magnetic flux can be suppressed.
In another different form of the invention, the air gap is provided inside the magnet insertion hole. When it is necessary to position the permanent magnet at a predetermined position in the magnet insertion hole, for example, positioning is performed on at least one of the first outer peripheral side wall and the first inner peripheral side wall forming the magnet insertion hole. A method of providing a positioning portion such as a protrusion or a stepped portion for positioning can be used.
In this embodiment, the gap can be easily formed.
In another different embodiment of the present invention, the air gap is provided between the magnet insertion hole and the outer peripheral surface of the rotor. As a method of providing a gap between the magnet insertion hole and the outer peripheral surface of the rotor, a method of forming a hole between the outer peripheral side wall of the magnet insertion hole and the outer peripheral surface of the rotor is typically used. .
In this embodiment, since the outer bridge portion is formed between the magnet insertion hole and the hole and between the hole and the outer peripheral surface of the rotor, the strength of the rotor against centrifugal force can be further increased.
In another different form of the present invention, the magnet insertion hole has a first magnet insertion hole and a second magnet insertion hole, and a central bridge portion is provided between the first magnet insertion hole and the second magnet insertion hole. Is formed. The permanent magnet has first and second permanent magnets inserted into the first and second magnet insertion holes.
In this embodiment, the strength of the rotor against centrifugal force can be further increased.
The magnet insertion hole can be arranged in various ways that can utilize both magnet torque and reluctance torque. For example, an aspect in which the center is arranged in a V shape protruding in the direction of the rotation center, an aspect in which the center is arranged in a straight line along the circumferential direction, and an aspect in which the center is arranged in a trapezoidal shape protruding in the rotation center direction are used. it can.

  In the permanent magnet motor of the present invention, the amount of magnetic flux can be secured while preventing demagnetization of the permanent magnet.

1 is a schematic configuration diagram of a first embodiment of a permanent magnet motor of the present invention. It is the elements on larger scale of the rotor which comprises the permanent magnet electric motor of 1st Embodiment. FIG. 3 is a partially enlarged view of FIG. 2. The angle θ formed by the first outer peripheral side wall part forming the magnet insertion part and the second inner peripheral side wall part forming the second part of the gap, the magnetic flux amount of the main magnetic flux, and the outer peripheral side end part of the permanent magnet It is a graph which shows the relationship with a demagnetization start current. It is the elements on larger scale of the rotor which comprises 2nd Embodiment of the permanent magnet electric motor of this invention. It is the elements on larger scale of the rotor which comprises 3rd Embodiment of the permanent magnet electric motor of this invention. It is a schematic block diagram of 4th Embodiment of the permanent magnet electric motor of this invention. It is the elements on larger scale of the rotor which comprises the permanent magnet electric motor of 4th Embodiment. It is a schematic block diagram of 5th Embodiment of the permanent magnet electric motor of this invention. It is the elements on larger scale of the rotor which comprises the permanent magnet electric motor of 5th Embodiment.

Embodiments of a permanent magnet motor according to the present invention will be described below with reference to the drawings.
In the present specification, the “axial direction” indicates the direction of the rotation center line passing through the rotation center of the rotor (rotating shaft) in a state where the rotor is rotatably arranged with respect to the stator. “Circumferential direction” refers to a circumferential direction centered on the rotation center as viewed in a cross section perpendicular to the axial direction (direction of the rotation center line) in a state where the rotor is rotatably arranged with respect to the stator. Show. The “radial direction” indicates a direction passing through the center of rotation as seen in a cross section perpendicular to the axial direction in a state where the rotor is rotatably arranged with respect to the stator.
“D-axis” indicates a line connecting the center of the main magnetic pole portion in the circumferential direction (main magnetic pole portion center) and the rotation center when viewed in a cross section perpendicular to the axial direction, and “q-axis” is perpendicular to the axial direction. As seen from a simple cross section, a line connecting the circumferential center (auxiliary magnetic pole portion center) of the auxiliary magnetic pole portion and the rotation center is shown.
In addition, “inner circumference side” indicates a rotation center side when viewed in a cross section perpendicular to the axial direction, and “outer circumference side” indicates a side opposite to the rotation center (of the rotor) when viewed in a cross section perpendicular to the axial direction. The outer peripheral surface side) is shown.
The description “parallel” is used to include “substantially parallel”.

  A first embodiment of the permanent magnet motor of the present invention will be described with reference to FIGS. FIG. 1 is a diagram illustrating a schematic configuration of a permanent magnet electric motor 200 according to the first embodiment, and FIG. 2 is a partially enlarged view of a rotor 400 configuring the permanent magnet electric motor 200 according to the first embodiment. 1 and 2 are cross-sectional views seen from a direction perpendicular to the axial direction.

The permanent magnet motor 200 according to the present embodiment includes a stator 300 and a rotor 400 that is arranged to be rotatable with respect to the stator 300.
The stator 300 is constituted by a stator core in which a plurality of electromagnetic steel plates are laminated, and when viewed in a cross section perpendicular to the axial direction, the stator 311 extends along the circumferential direction, and the center of rotation along the radial direction from the yoke 311. It has a plurality of teeth 312 extending to the O side. The teeth 312 have a teeth base 312a extending along the radial direction, and a teeth tip 312b provided on the distal end side of the teeth base 312a and extending along the circumferential direction. The teeth tip portion 312b has a teeth tip surface 312c on the side facing the rotor 400 (outer peripheral surface 400a). Although not shown, a stator winding is inserted into a slot 313 formed by teeth 312 adjacent in the circumferential direction.

The rotor 400 is constituted by a rotor core in which a plurality of electromagnetic steel plates are laminated, and the main magnetic pole portions [A] to [D] and the auxiliary magnetic pole portion [AB] along the circumferential direction when viewed in a cross section perpendicular to the axial direction. ] To [DA] are alternately arranged.
In the present embodiment, the outer peripheral surface 400a of the rotor 400 is formed in a circular shape when viewed in a cross section perpendicular to the axial direction. The rotor 400 is arranged such that the length G of the gap (air gap) between the outer peripheral surface 400a of the rotor 400 and the inner peripheral surface (tooth tip surface 312c) of the stator 300 becomes a predetermined value.

Magnet insertion holes are formed in the main magnetic pole portions [A] to [D], and permanent magnets are inserted into the magnet insertion holes.
Since the main magnetic pole parts [A] to [D] and the auxiliary magnetic pole parts [AB] to [DA] arranged between the main magnetic pole parts [A] to [D] have the same configuration, FIG. The configuration of the main magnetic pole part [A] will be described with reference to FIG.

  In the present embodiment, the main magnetic pole part [A] has a first magnet insertion hole 410A1 and a second magnet insertion hole 410A2 on both sides of the main magnetic pole part center line (d-axis) along the circumferential direction. Is formed. The first permanent magnet 450A1 is inserted into the first magnet insertion hole 410A1, and the second permanent magnet 450A2 is inserted into the second magnet insertion hole 410A2. The first magnet insertion hole 410A1 and the second magnet insertion hole 410A2, and the first permanent magnet 450A1 and the second permanent magnet 450A2 are arranged in a V shape with the center protruding in the direction of the rotation center O.

In the present embodiment, the first magnet insertion hole 410A1 and the second magnet insertion hole 410A2, and the first permanent magnet 450A1 and the second permanent magnet 450A2 are the center of the main magnetic pole portion as viewed in a cross section perpendicular to the axial direction. It is formed so as to be line symmetric with respect to the line (d-axis).
The first permanent magnet 450A1 has a cross-sectional shape perpendicular to the axial direction such that the outer peripheral side wall portion 451A1, the inner peripheral side wall portion 452A1, the inner peripheral side end wall portion 453A1, and the outer peripheral side end wall portion 454A1 have a rectangular shape ("substantially square"). Including).
Like the first permanent magnet 450A1, the second permanent magnet 450A2 has a cross-sectional shape of a quadrangle by the outer peripheral side wall portion 451A2, the inner peripheral side wall portion 452A2, the inner peripheral side end wall portion 453A2, and the outer peripheral side end wall portion 454A2. Is formed.

The first magnet insertion hole 410A1 includes a first outer peripheral side wall 411A1, a first inner peripheral side wall 412A1, an inner peripheral side end wall 413A1, an outer peripheral side end wall 414A1, a second inner peripheral side wall 415A1, It has a second outer peripheral side wall portion 416A1 and a connecting end wall portion 417A1.
The first outer peripheral side wall portion 411A1 and the first inner peripheral side wall portion 412A1 extend in parallel (including “substantially parallel”) in a direction inclined with respect to the q axis of the adjacent auxiliary magnetic pole portion [DA]. ing. The inner peripheral side end wall portion 413A1 is connected to the end portion of the first outer peripheral side wall portion 411A1 and the first inner peripheral side wall portion 412A1 on the center side (d axis side) of the main magnetic pole portion, and is parallel to the d axis ("substantially" (Including “parallel”). The outer peripheral side end wall portion 414A1 is connected to the end portion on the outer peripheral surface 400a side of the rotor 400 of the first inner peripheral side wall portion 412A1, and extends in the main magnetic pole portion center (d-axis) direction along the circumferential direction. doing. The outer peripheral side end wall portion 414A1 may extend linearly, or may extend in an arc shape parallel to (including “substantially parallel”) the outer peripheral surface 400a of the rotor 400. The second inner peripheral side wall part 415A1 and the second outer peripheral side wall part 416A1 are respectively the end part on the outer peripheral surface 400a side of the rotor 400 and the main magnetic pole part of the outer peripheral side end wall part 414A1 of the first outer peripheral side wall part 411A1. It is connected to the end portion on the center side (d-axis side) and extends in parallel (including “substantially parallel”) to the central direction of the main magnetic pole portion. The connecting end wall portion 417A1 is connected to the ends of the second inner peripheral side wall portion 415A1 and the second outer peripheral side wall portion 416A1 on the center side of the main magnetic pole portion, and extends along the radial direction.
A protrusion 418A1 for positioning the first permanent magnet 450A1 at a predetermined position in the first magnet insertion hole 410A1 protrudes into the first magnet insertion hole 410A1 on the first inner peripheral side wall 412A1. Is provided. Note that the positioning protrusions only have to be provided on at least one of the first outer peripheral side wall 411A1 and the first inner peripheral side wall 412A1. In addition, positioning members other than the protrusions can be provided.

  In the present embodiment, a magnet insertion portion into which the first permanent magnet 450A1 is inserted is formed by the first outer peripheral side wall portion 411A1, the first inner peripheral side wall portion 412A1, and the inner peripheral side end wall portion 413A1. The first outer peripheral side wall portion 411A1 and the first inner peripheral side wall portion 412A1 of the first magnet insertion hole 410A1 extend along the direction inclined with respect to the q axis of the adjacent auxiliary magnetic pole portion [DA]. Since the inner peripheral side end wall portion 413A1 is arranged in parallel to the d-axis and the first permanent magnet 450A1 has a quadrangular cross section, the inner peripheral side end wall portion 453A1 of the first permanent magnet 450A1 and the first permanent magnet 450A1 A gap 441A1 is formed between the inner peripheral side end wall portions 413A1 of one magnet insertion hole 410A1.

Further, a first air gap 442A1 is formed between the outer peripheral side end wall portion 454A1 of the first permanent magnet 450A1 and the outer peripheral surface 400a of the rotor 400.
In the present embodiment, the first gap 442A1 includes a first portion facing the outer peripheral side end wall portion 454A1 of the first permanent magnet 450A1, and a central direction of the main magnetic pole portion from the first portion along the circumferential direction ( a second portion extending in the d-axis direction). The first portion of the first gap 442A1 is formed by the first outer peripheral side wall 411A1, the first inner peripheral side wall 412A1, and the outer peripheral side end wall 414A1. The second portion of the first gap 442A1 is formed by the second inner peripheral side wall portion 415A1, the second outer peripheral side wall portion 416A1, and the connecting end wall portion 417A1.
The first gap 442A1 prevents the magnetic flux (main magnetic flux) of the first permanent magnet 450A1 from being short-circuited.

Similarly to the first magnet insertion hole 410A1, the second magnet insertion hole 410A2 includes a first outer peripheral side wall part 411A2, a first inner peripheral side wall part 412A2, an inner peripheral side end wall part 413A2, and an outer peripheral side end wall part. 414A2, a second inner peripheral side wall 415A2, a second outer peripheral side wall 416A2, and a connecting end wall 417A2. A protrusion 418A2 for positioning the second permanent magnet 450A2 at a predetermined position in the second magnet insertion hole 410A2 protrudes into the second magnet insertion hole 410A2 on the first inner peripheral wall portion 412A2. Is provided.
The first outer peripheral side wall portion 411A2, the first inner peripheral side wall portion 412A2, and the inner peripheral side end wall portion 413A2 form a magnet insertion portion into which the second permanent magnet 450A2 is inserted. Further, the first outer peripheral side wall portion 411A2, the first inner peripheral side wall portion 412A2, the outer peripheral side end wall portion 414A2, the second inner peripheral side wall portion 415A2, the second outer peripheral side wall portion 416A2, and the connecting end wall portion 417A2. A second gap 442A2 is formed between the outer peripheral side wall 454A2 of the second permanent magnet 450A2 and the outer peripheral surface 400a of the rotor 400.

  In the present embodiment, the first outer peripheral side wall 411A1 of the first magnet insertion hole 410A1 and the first outer peripheral side wall 411A2 of the second magnet insertion hole 410A2 are the “first forming the magnet insertion part”. The first inner peripheral side wall portion 412A1 of the first magnet insertion hole 410A1 and the first inner peripheral side wall portion 412A2 of the second magnet insertion hole 410A2 correspond to the “outer peripheral side wall portion of the first magnet insertion hole 410A1”. Corresponds to the “first inner peripheral side wall portion forming the portion”. Further, the second inner peripheral side wall 415A1 of the first magnet insertion hole 410A1 and the second inner peripheral side wall 415A2 of the second magnet insertion hole 410A2 form the “second portion of the gap” according to the present invention. Corresponding to the “second inner peripheral side wall”, the second outer peripheral side wall 416A1 of the first magnet insertion hole 410A1 and the second outer peripheral side wall 416A2 of the second magnet insertion hole 410A2 are the “gap” of the present invention. Corresponds to a “second outer peripheral side wall portion that forms the second portion of the second portion”. Further, the outer peripheral side end wall portion 454A1 of the first permanent magnet 450A1 and the outer peripheral side end wall portion 454A2 of the second permanent magnet 450A2 correspond to the “outer peripheral side end wall portion of the permanent magnet” of the present invention.

In the present embodiment, between the first magnet insertion hole 410A1 and the second magnet insertion hole 410A2, that is, between the inner peripheral side end wall 413A1 of the first magnet insertion hole 410A1 and the second magnet insertion hole 410A2. A central bridge portion 431A is formed between the peripheral side end wall portions 413A2.
Further, the first outer peripheral bridge portion 432A is provided between the first magnet insertion hole 410A1 and the outer peripheral surface 400a of the rotor 400, that is, between the outer peripheral side end wall portion 414A1 and the outer peripheral surface 400a of the first magnet insertion hole 410A1. Is formed. Similarly, the second outer peripheral bridge portion between the second magnet insertion hole 410A2 and the outer peripheral surface 400a of the rotor 400, that is, between the outer peripheral side end wall portion 414A2 and the outer peripheral surface 400a of the second magnet insertion hole 410A2. 433A is formed.
The inner peripheral bridge portion 431A, the first outer peripheral bridge portion 432A, and the second outer peripheral bridge portion 433A increase the strength of the rotor 400 against the centrifugal force generated during rotation.

  In the other main magnetic pole portions [B] to [D], first magnet insertion holes 410B1 to 410D1 and second magnet insertion holes 410B2 to 410D2 having the same configuration as the main magnetic pole portion [A] are formed, respectively. The first permanent magnets 450B1 to 450D1 and the second permanent magnets 450B2 to 450D2 are inserted. Auxiliary magnetic pole portions [AB] to [DA] are formed between the main magnetic pole portions [A] to [D]. Thereby, the permanent magnet electric motor 200 of this embodiment can utilize both magnet torque and reluctance torque.

Next, a specific configuration of the present embodiment will be described with reference to FIG. 3 which is a partially enlarged view of FIG.
Here, the angle formed by the second inner peripheral side wall portion 415A1 forming the second portion of the first gap 442A1 and the first outer peripheral side wall portion 411A1 forming the magnet insertion portion is θ (degrees). To do.
Further, the length when the second inner peripheral side wall portion 415A1 (length M) that forms the second portion of the first gap 442A1 is projected onto the first outer peripheral side wall portion 411A1 that forms the magnet insertion portion. Let N be the length along the extending direction of the first outer peripheral side wall 411A1. The extending direction of the first permanent magnet 450A1 (the extending direction of the outer peripheral wall portion 451A1 or the inner peripheral wall portion 452A1) is parallel to the extending direction of the first outer peripheral wall portion 411A1 of the first magnet insertion hole 410A1. Therefore, projecting the length M of the second inner peripheral side wall portion 415A1 onto the first outer peripheral side wall portion 411A1 means that the length M of the second inner peripheral side wall portion 415A1 is changed to that of the first permanent magnet 450A1. Equivalent to projecting in the extending direction.
Furthermore, the end Q on the main magnetic pole part center side (d-axis side) of the second inner peripheral side wall part 415A1 forming the second part of the first gap 442A1 is used as the first outer periphery forming the magnet insertion part. The length from the position R projected on the side wall part 411A1 to the outer peripheral side end wall part 454A1 of the first permanent magnet 450A1 is L.

FIG. 4 shows the angle θ (degrees), the demagnetization start current at the outer peripheral end of the first permanent magnet 450A1 (near the outer peripheral end wall 454A1), and the amount of magnetic flux of the main magnetic flux flowing through the main magnetic pole [A]. It is a graph which shows the relationship. In FIG. 4, the horizontal axis represents the angle θ, one vertical axis represents the amount of magnetic flux, and the other vertical axis represents the demagnetization start current. The demagnetization start current represents the current at which demagnetization starts. That is, the smaller the demagnetization start current, the easier it is to demagnetize.
In FIG. 4, the solid line is a graph showing the amount of main magnetic flux. The solid line X1 is a graph of the amount of magnetic flux when [(L / N) = 0.95], the solid line X2 is the graph of magnetic flux when [(L / N) = 0.72], and the solid line X3 is [ A graph of the amount of magnetic flux when (L / N) = 0.7], and a solid line X4 is a graph of the amount of magnetic flux when [(L / N) = 0.68].
The broken line is a graph showing the demagnetization start current. The broken line Y1 is a graph of demagnetization start current when [(L / N) = 0.95], and the broken line Y2 is a graph of demagnetization start current when [(L / N) = 0.72]. The broken line Y3 is a graph of the demagnetization start current when [(L / N) = 0.7], and the broken line Y4 is a graph of the demagnetization start current when [(L / N) = 0.68]. is there.

From FIG. 4, it can be understood that the amount of the main magnetic flux increases as the angle θ increases. This is because the main magnetic flux extends to the depth of the depression as the opening of the depression formed by the first inner circumferential wall 411A1 and the second inner circumferential wall 415A1 of the first magnet insertion hole 410A1 becomes larger (first permanent This is because it flows to the outer peripheral side end of the magnet 450A1. The magnetic flux amount of the main magnetic flux increases as (L / N) increases, that is, the outer peripheral side end wall portion 454A1 of the first permanent magnet 450A1 has the first inner peripheral side wall portion 411A1 and the second inner peripheral side wall. It can be understood that it increases as it is arranged in the back of the recess formed by the portion 415A1. This is because the magnet amount of the first permanent magnet 450A1 increases as (L / N) increases.
Here, from FIG. 4, when (L / N) is smaller than 0.7, [(L / N) <0.7], and when (L / N) is 0.7 or more [0.7 ≦ ( L / N)], it can be understood that the amount of magnetic flux is small. Furthermore, when (L / N) is 0.7 or more [0.7 ≦ (L / N)], in the region [38 degrees ≦ θ] where the angle θ is 38 degrees or more, the angle θ increases. Although the amount of magnetic flux gradually increases, it can be understood that when the angle θ is smaller than 38 degrees [θ <38 degrees], the amount of magnetic flux rapidly decreases.

Further, it can be understood from FIG. 4 that the demagnetization start current at the outer peripheral side end of the first permanent magnet 450A1 decreases as the angle θ increases. This is because the larger the opening of the recess formed by the first inner peripheral side wall portion 411A1 and the second inner peripheral side wall portion 415A1, the easier the magnetic flux concentrates on the outer peripheral side end portion of the first permanent magnet 450A1. This is because the outer peripheral side end portion of one permanent magnet 450A1 is easily demagnetized. As the demagnetization start current becomes smaller (L / N), that is, the outer peripheral side end wall portion 454A1 of the first permanent magnet 450A1 has the first inner peripheral side wall portion 411A1 and the second inner peripheral side wall portion. It can be understood that the lower the position is on the opening side of the recess formed by 415A1. This is because the smaller the (L / N), the easier the magnetic flux concentrates on the outer peripheral side end of the first permanent magnet 450A1.
Here, from FIG. 4, when (L / N) is smaller than 0.7, [(L / N) <0.7], and when (L / N) is 0.7 or more [0.7 ≦ ( L / N)], it can be understood that the demagnetization start current is greatly reduced. Further, when (L / N) is 0.7 or more [0.7 ≦ (L / N)], in the region [θ ≦ 44 degrees] where the angle θ is 44 degrees or less, the angle θ increases. Although the demagnetization start current gradually decreases, it can be understood that when the angle θ exceeds 44 degrees [44 degrees <θ], the demagnetization start current rapidly decreases.

In the case where the outer peripheral side end wall portion 454A1 of the first permanent magnet 450A1 is disposed on the outer peripheral side from the connection portion between the first inner peripheral side wall portion 411A1 and the second inner peripheral side wall portion 415A1 [1.0. In <(L / N)], the magnet portion on the outer peripheral side from the connection location is not effectively used.
From the above, by configuring so that [38 degrees ≦ θ ≦ 44 degrees] and [0.7 ≦ (L / N) ≦ 1.0] are satisfied, the decrease in demagnetization start current is suppressed. However, it can be understood that the magnetic flux amount of the main magnetic flux can be ensured (while suppressing the demagnetization of the outer peripheral end of the permanent magnet).

Next, the interval S between the second inner peripheral side wall 415A1 and the second outer peripheral side wall 416A1 that forms the second portion of the first gap 442A1 will be considered. Here, the thickness of the first permanent magnet 450A1 is H, and the length of the gap between the inner peripheral surface (tooth tip surface 312c) of the stator 300 and the outer peripheral surface 400a of the rotor 400 is G.
If the distance S is smaller than the gap G between the inner peripheral surface 312c of the stator 300 and the outer peripheral surface 400a of the rotor 400, the effect of preventing a short circuit of the main magnetic flux is low.
If the distance S is larger than the thickness H of the first permanent magnet 450A1, it is difficult to increase the length of the first permanent magnet 450A1, and the amount of main magnetic flux cannot be secured. In this case, since the magnet torque decreases, it is necessary to increase the current supplied to the stator winding.
Therefore, it is preferable that [G ≦ S ≦ H] is satisfied so that the amount of the main magnetic flux can be secured while preventing the main magnetic flux from being short-circuited.

Next, the length when the second inner peripheral side wall portion 415A1 (length M) forming the second portion of the first gap 442A1 is projected onto the first outer peripheral side wall portion 411A1 forming the magnet insertion portion. Consider the minimum value of the length N. If the length N is less than the thickness H of the first permanent magnet 450A1, the end portion on the outer peripheral side of the first permanent magnet 450A1 may be demagnetized.
Therefore, in order to prevent demagnetization at the outer peripheral side end portion of the first permanent magnet 450A1 and to secure the amount of main magnetic flux, it is preferable that [H ≦ L] is satisfied.

Next, the minimum value T of the distance between the first gap 442A1 and the outer peripheral surface 400a of the rotor 400 will be examined. The minimum value T between the first gap 442A1 and the outer peripheral surface 400a of the rotor 400 is the minimum value of the distance between the outer peripheral end wall 414A1 of the first magnet insertion hole 410A1 and the outer peripheral surface 400a of the rotor 40. . A first outer peripheral bridge portion 432A is formed between the outer peripheral side end wall portion 414A1 and the outer peripheral surface 400a of the rotor 400.
Therefore, it is preferable to configure so that [0.4 mm ≦ T ≦ 1.0 mm] is satisfied in order to ensure the strength of the rotor 400 against centrifugal force and to suppress a short circuit of the main magnetic flux.

  Next, another embodiment of the permanent magnet motor of the present invention will be described. The permanent magnet motor of each embodiment described below has the same configuration except for the magnet insertion hole formed in the rotor and the permanent magnet inserted in the magnet insertion hole. Only the hole and the permanent magnet will be described.

FIG. 5 shows a partially enlarged view of a rotor 500 constituting the permanent magnet motor according to the second embodiment of the present invention.
In the rotor 400 of the first embodiment, a gap is provided in the magnet insertion hole between the outer peripheral side wall of the permanent magnet and the outer peripheral surface of the rotor. However, in the rotor 500 of the present embodiment, It is provided between the magnet insertion hole and the outer peripheral surface of the rotor.
In the main magnetic pole portion [A] of the rotor 500 of the present embodiment, the first magnet insertion hole 510A1 and the first hole 520A1 and the second magnet insertion hole are provided on both sides of the d axis along the circumferential direction. 510A2 and a second hole 520A2 are formed. Then, the first permanent magnet 550A1 is inserted into the first magnet insertion hole 510A1, and the second permanent magnet 550A2 is inserted into the second magnet insertion hole 510A2.
The first magnet insertion hole 510A1 and the second magnet insertion hole 510A2, and the first permanent magnet 550A1 and the second permanent magnet 550A2 are arranged in a V shape with the center protruding in the direction of the rotation center O.

The first magnet insertion hole 510A1 is disposed on the inner peripheral side with respect to the outer peripheral side wall 511A1, the outer peripheral side wall 511A1, and extends in parallel with the outer peripheral side wall 511A1, the inner peripheral side wall 513A1, and the inner peripheral side wall 513A1. It has an outer peripheral side end wall portion 514A1. The first permanent magnet 550A1 has a cross-sectional shape perpendicular to the axial direction, which is formed into a quadrangle by an outer peripheral side wall portion 551A1, an inner peripheral side wall portion 552A1, an inner peripheral side end wall portion 553A1, and an outer peripheral side end wall portion 554A1. Yes.
In the present embodiment, the first permanent magnet 550A1 is inserted by the outer peripheral side wall portion 511A1, the inner peripheral side wall portion 512A1, the inner peripheral side end wall portion 513A1, and the outer peripheral side end wall portion 514A1 of the first magnet insertion hole 510A1. A magnet insertion part is formed.

The first hole 520A1 is formed between the first magnet insertion hole 510A1 and the outer peripheral surface 500a of the rotor 500.
The first hole 520A1 includes a first connecting end wall 521A1, an inner peripheral side wall 522A1, an outer peripheral end wall 523A1, an inner peripheral side wall 524A1, an outer peripheral side wall 525A1, and a second connecting end wall. 526A1.
The inner peripheral side end wall portion 522A1 is disposed at a position facing the outer peripheral side end wall portion 514A1 of the first magnet insertion hole 510A1, and extends in parallel with the outer peripheral side end wall portion 514A. The first connecting end wall 521A1 is connected to the end of the inner peripheral side end wall 522A1 on the side of the adjacent auxiliary magnetic pole (the auxiliary magnetic pole [DA] in FIG. 5), and along the q axis. It extends in the outer circumferential direction. The outer peripheral side end wall portion 523A1 is connected to the outer peripheral side end portion of the first connecting end wall portion 521A1, and extends in the central direction of the main magnetic pole portion (d-axis direction) along the circumferential direction. The inner peripheral side wall portion 524A1 and the outer peripheral side wall portion 525A1 are connected to the ends of the inner peripheral side wall portion 522A1 and the outer peripheral side end wall portion 523A1 on the center side (d-axis side) of the main magnetic pole portion, respectively, and are parallel in the circumferential direction. It is extended. The second connecting end wall portion 526A1 is connected to the ends of the inner peripheral side wall portion 524A1 and the outer peripheral side wall portion 525A1 on the center side of the main magnetic pole portion, and extends along the radial direction.
In the present embodiment, the first gap 542A1 is arranged between the outer peripheral side end wall portion 554A1 of the first permanent magnet 550A1 and the outer peripheral surface 500a of the rotor 500 by the first hole 520A1. The first connecting end wall portion 521A1, the inner peripheral side end wall portion 522A1 and the outer peripheral side end wall portion 523A1 form a first portion of the first gap 542A1, and the inner peripheral side wall portion 524A1 and the outer peripheral side wall. By the portion 525A1 and the second connecting end wall portion 526A1, the second portion of the first gap 542A1 (second portion extending from the first portion toward the center of the main magnetic pole portion along the circumferential direction) is formed. Is formed.

Similarly to the first magnet insertion hole 510A1, the second magnet insertion hole 510A2 has an outer peripheral side wall part 511A2, an inner peripheral side wall part 512A2, an inner peripheral side end wall part 513A2, and an outer peripheral side end wall part 514A2. . The outer peripheral side wall portion 511A2, the inner peripheral side wall portion 512A2, the inner peripheral side end wall portion 513A2 and the outer peripheral side end wall portion 514A2 form a magnet insertion portion into which the second permanent magnet 550A2 is inserted.
Similarly to the first hole 520A1, the second hole 520A2 includes the first connecting end wall 521A2, the inner peripheral wall 522A2, the outer peripheral end wall 523A2, the inner peripheral wall 524A2, and the outer peripheral wall. Portion 525A2 and second connecting end wall 526A2. A second gap 542A2 is arranged between the outer peripheral side end wall portion 554A2 of the second permanent magnet 550A2 and the outer peripheral surface 500a of the rotor 500 by the second hole 520A2.

  In the present embodiment, the first outer peripheral side wall portion 511A1 of the first magnet insertion hole 510A1 and the first outer peripheral side wall portion 511A2 of the second magnet insertion hole 510A2 are “the first forming the magnet insertion portion”. The first inner peripheral wall portion 512A1 of the first magnet insertion hole 510A1 and the first inner peripheral wall portion 512A2 of the second magnet insertion hole 510A2 correspond to the “outer peripheral side wall portion of the first magnet insertion hole 510A1”. Corresponds to the “first inner peripheral side wall portion forming the portion”. Further, the inner peripheral side wall 522A1 of the first hole 520A1 and the inner peripheral side wall 522A2 of the second hole 520A2 correspond to the “second inner peripheral side wall forming the second portion of the gap” of the present invention. The outer peripheral side wall 523A1 of the first hole 520A1 and the outer peripheral side wall 523A2 of the second hole 520A2 correspond to the “second outer peripheral side wall forming the second portion of the gap” in the present invention. Further, the outer peripheral side end wall portion 554A1 of the first permanent magnet 550A1 and the outer peripheral side end wall portion 554A2 of the second permanent magnet 550A2 correspond to “the outer peripheral side end wall portion of the permanent magnet” of the present invention.

In the present embodiment, a center bridge portion 531A is formed between the first magnet insertion hole 510A1 (inner peripheral side end wall portion 513A1) and the second magnet insertion hole 510A2 (inner peripheral side end wall portion 513A2). .
A first outer bridge 532A is formed between the first hole 520A1 (outer peripheral end wall 523A1) and the outer peripheral surface 500a of the rotor 500, and the first magnet insertion hole 510A1 (outer peripheral). A second outer peripheral bridge portion 534A is formed between the end wall portion 514A1) and the first hole 520A1 (inner peripheral side end wall portion 522A1). Similarly, a third outer bridge portion 533A is formed between the second hole 520A2 (outer peripheral side end wall 523A2) and the outer peripheral surface 500a of the rotor 500, and the second magnet insertion hole 510A2 (outer peripheral A fourth outer peripheral bridge portion 535A is formed between the side end wall portion 514A2) and the second hole 520A2 (inner peripheral side end wall portion 522A2).
The inner peripheral bridge portion 531A and the first to fourth outer peripheral bridge portions 532A, 534A, 533A, and 535A can further increase the strength of the rotor 500 against the centrifugal force generated during rotation.
In the present embodiment, a positioning member for positioning the permanent magnet at a predetermined position in the magnet insertion hole is not provided, but a positioning member can also be used.

In the present embodiment, the outer peripheral side wall portion 511A1 of the first magnet insertion hole 510A1 (the outer peripheral side wall portion 511A2 of the second magnet insertion hole 510A2) is the “first outer peripheral side wall portion forming the magnet insertion portion” of the present invention. The inner peripheral side wall portion 512A1 of the first magnet insertion hole 510A1 (the inner peripheral side wall portion 512A2 of the second magnet insertion hole 510A2) corresponds to the “first inner peripheral side wall forming the magnet insertion portion” of the present invention. Part. Also, the inner peripheral side wall portion 524A1 of the first hole 520A1 (the inner peripheral side wall portion 524A2 of the second hole 520A2 corresponds to the “second inner peripheral side wall portion forming the second portion of the gap” of the present invention). The outer peripheral side wall 525A1 of the first hole 520A1 (the outer peripheral side wall 525A2 of the second hole 520A2) corresponds to the “second outer peripheral side wall forming the second portion of the gap” in the present invention.
Further, “the outer peripheral side wall portion 511A1 of the first magnet insertion hole 510A1 (the outer peripheral side wall portion 511A2 of the second magnet insertion hole 510A2) and the inner peripheral side wall portion 524A1 of the first hole 520A1 (the inner periphery of the second hole 520A2). The “connection portion on the extension line of the side wall portion 524A2)” corresponds to “the connection portion between the first outer peripheral side wall portion 411A1 and the second inner peripheral side wall portion 415A1” in the first embodiment shown in FIG. To do.
The angle θ, (L / N), the thickness H of the permanent magnet, the length L, and the minimum value T of the gap between the air gap and the outer peripheral surface of the rotor are the same as in the first embodiment.

FIG. 6 shows a partially enlarged view of a rotor 600 constituting the permanent magnet motor of the third embodiment of the present invention.
In the rotor 400 of the first embodiment, the protrusion (positioning member) for positioning the permanent magnet at a predetermined position in the magnet insertion hole is provided. In the rotor 600 of the present embodiment, the wall member of the magnet insertion hole is provided. Are provided with a stepped portion for positioning.
The rotor 600 of this embodiment is different from the rotor 400 of the first embodiment only in that a step is provided on the wall member of the magnet insertion hole, and therefore only the step is described.

In the main magnetic pole portion [A] of the rotor 600 of the present embodiment, the first magnet insertion holes 610A1 are arranged on both sides of the d-axis along the circumferential direction, similarly to the rotor 400 of the first embodiment. And a second magnet insertion hole 610A2.
The first magnet insertion hole 610A1 includes a first outer peripheral side wall 611A1, a first inner peripheral side wall 612A1, a second inner peripheral side wall 613A1, an inner peripheral end wall 614A1, an outer peripheral side end wall 615A1, It has a third inner peripheral side wall 616A1, a second outer peripheral side wall 617A1, and a connecting end wall 618A1.
In the second inner peripheral side wall 613A1, the distance between the second inner peripheral side wall 613A1 and the first outer peripheral side wall 611A1 is smaller than the distance between the first inner peripheral side wall 612A1 and the first outer peripheral side wall 611A1. Are arranged as follows. That is, the second inner peripheral side wall portion 613A1 and the first inner peripheral side wall portion 612A1 are arranged in steps. The distance between the second inner peripheral side wall 613A1 and the first outer peripheral side wall 611A1 is shorter than the length of the outer peripheral side end wall 654A1 of the first permanent magnet 650A1 inserted into the first magnet insertion hole 610A1. Is set. Thereby, the boundary part (step part) of 2nd inner peripheral side wall part 613A1 and 1st inner peripheral side wall part 612A1 positions 1st permanent magnet 650A1 in the predetermined position in 610A of 1st magnet insertion holes. It acts as a positioning member.

In the present embodiment, the magnet into which the first permanent magnet 650A1 is inserted by the first outer peripheral side wall 611A1, the first inner peripheral side wall 612A1 and the inner peripheral side end wall 614A1 of the first magnet insertion hole 610A1. An insertion part is formed.
The first outer peripheral side wall 611A1, the second inner peripheral side wall 613A1, and the outer peripheral side end wall 615A1 form a first portion of the first gap 642A1, and the second inner peripheral side wall 616A1, A second portion of the first air gap 642A1 (second portion extending from the first portion toward the center of the main magnetic pole portion along the circumferential direction) by the two outer peripheral side wall portions 617A1 and the connecting end wall portion 618A1. Is formed.
Other configurations are the same as those of the rotor 400 of the first embodiment.

A rotor 700 constituting a permanent magnet motor according to a fourth embodiment of the present invention will be described with reference to FIGS. 7 is a cross-sectional view showing a schematic configuration of the rotor 700, and FIG. 8 is a partially enlarged view of FIG. In the rotor 700 of this embodiment, the magnet insertion holes and the permanent magnets are linearly arranged along the circumferential direction.
In the rotor 700 of this embodiment, magnet insertion holes 710A to 710D are formed in the main magnetic pole portions [A] to [D], and permanent magnets 750A to 750D are inserted in the magnet insertion holes 710A to 710D.
Since the main magnetic pole portions [A] to [D] have the same configuration, the configuration of the main magnetic pole portion [A] will be described below with reference to FIG.

The magnet insertion hole 710A includes a first outer peripheral side wall 711A, a first inner peripheral side wall 712A, a first connecting end wall 713A1, a first outer peripheral side end wall 714A1, and a second inner peripheral side wall. 715A1, second outer peripheral side wall portion 716A1, second connecting end wall portion 717A1, third connecting end wall portion 713A2, second outer peripheral side end wall portion 714A2, third inner peripheral side wall portion 715A2, 3 outer peripheral side wall portions 716A2 and a fourth connecting end wall portion 717A2.
The first outer peripheral side wall portion 711A and the first inner peripheral side wall portion 712A extend in parallel in a direction orthogonal to the d-axis.
The first connecting end wall portion 713A1 is connected to an end portion on one side (left side in FIG. 8) along the circumferential direction of the first inner circumferential side end wall portion 712A, and one side along the circumferential direction. The auxiliary magnetic pole part (auxiliary magnetic pole part [DA] in FIG. 8) adjacent to the side extends along the q axis. The first outer peripheral side end wall portion 714A1 is connected to the outer peripheral side end portion of the first connecting end wall portion 713A1, and extends in the central direction of the main magnetic pole portion (d-axis direction) along the circumferential direction. Yes. The second inner peripheral side wall portion 715A1 and the second outer peripheral side wall portion 716A1 are respectively located at one end along the circumferential direction of the first outer peripheral side wall portion 711A1 and the main magnetic pole center side of the outer peripheral side end wall portion 714A1. It is connected to the end on the (d-axis side) and extends in the main magnetic pole center direction along the circumferential direction. The second connecting end wall 717A1 is connected to the ends of the second inner peripheral side wall 715A1 and the second outer peripheral side wall 716A1 on the main magnetic pole part center side, and extends along the radial direction. .
The third connecting end wall 713A2 is connected to the end of the first inner peripheral side end wall 712A on the other side (right side in FIG. 8) along the circumferential direction, and the other along the circumferential direction. It extends along the q-axis of the auxiliary magnetic pole portion adjacent to the side (in FIG. 8, auxiliary magnetic pole portion [AB]). The second outer peripheral side end wall 714A2 is connected to the outer peripheral side end of the third connecting end wall 713A2, and extends in the main magnetic pole part central direction (d-axis direction) along the circumferential direction. Yes. The third inner peripheral side wall portion 715A2 and the third outer peripheral side wall portion 716A2 are respectively located at the other end in the circumferential direction of the first outer peripheral side wall portion 711A and the main magnetic pole center side of the outer peripheral side end wall portion 714A2. It is connected to the end on the (d-axis side) and extends in the main magnetic pole center direction along the circumferential direction. The fourth connecting end wall 717A2 is connected to the ends of the third inner peripheral side wall 715A2 and the third outer peripheral side wall 716A2 on the center side of the main magnetic pole portion, and extends along the radial direction. .

A first protrusion 718A1 and a second protrusion 718A2 for positioning the permanent magnet 750A at a predetermined position in the magnet insertion hole 710A protrude into the magnet insertion hole 710A1 on the first inner peripheral wall 712A. It is provided as follows.
Note that the positioning protrusions only need to be provided on at least one of the first outer peripheral side wall 711A and the first inner peripheral side wall 712A. In addition, positioning members other than the protrusions can be provided.
Or you may provide the level | step-difference part for positioning in at least one of a 1st outer peripheral side wall part and a 1st inner peripheral side wall part like the rotor 600 of 3rd Embodiment.
Moreover, like the rotor 500 of 2nd Embodiment, a hole can be formed between a magnet insertion hole and the outer peripheral surface of a rotor, and a positioning member can also be abbreviate | omitted.

In the present embodiment, a magnet insertion part into which the permanent magnet 750A is inserted is formed by the first outer peripheral side wall part 711A and the first inner peripheral side wall part 712A.
The first outer peripheral side wall 711A, the first inner peripheral side wall 712A, the first connecting end wall 713A1, the first outer peripheral side end wall 714A1, the second inner peripheral side wall 715A1, the second The first gap 741A1 is formed between the one end wall 753A along the circumferential direction of the permanent magnet 750A and the outer peripheral surface 700a of the rotor 700 by the outer peripheral side wall 716A1 and the second connecting end wall 717A1. Is formed. The first outer peripheral side wall portion 711A, the first inner peripheral side wall portion 712A, the first connecting end wall portion 713A1, and the first outer peripheral side end wall portion 714A1 make the first portion of the first gap 741A1. The second inner peripheral wall portion 715A1, the second outer peripheral side wall portion 716A1, and the second connecting end wall portion 717A1 form the second portion of the first gap 741A1.
Similarly, the first outer peripheral side wall 711A, the first inner peripheral side wall 712A, the third connecting end wall 713A2, the second outer peripheral side end wall 714A2, the third inner peripheral side wall 715A2, the first 3, the second gap 741A2 between the other end wall 754A along the circumferential direction of the permanent magnet 750A and the outer circumferential surface 700a of the rotor 700 by the outer circumferential side wall 716A2 and the fourth connecting end wall 717A2. Is formed. The first portion of the second gap 741A2 is defined by the first outer peripheral side wall portion 711A, the first inner peripheral side wall portion 712A, the third connecting end wall portion 713A2, and the second outer peripheral side end wall portion 714A2. A second portion of the second gap 741A2 is formed by the third inner peripheral side wall 715A2, the third outer peripheral side wall 716A2 and the fourth connecting end wall 717A2.
In this embodiment, an outer peripheral bridge portion is formed between one side and the other side along the circumferential direction of the magnet insertion hole 710A1 and the outer peripheral surface 700a of the rotor 700. That is, the first outer peripheral bridge portion 731A is formed between the first outer peripheral side end wall portion 714A1 of the magnet insertion hole 710A and the outer peripheral surface 700a, and the second outer peripheral side end wall portion 714A2 of the magnet insertion hole 710A and the outer peripheral surface are formed. A second outer peripheral bridge portion 732A is formed between the surfaces 700a.

  In the present embodiment, the first outer peripheral side wall portion 711A of the magnet insertion hole 710A corresponds to the “first outer peripheral side wall portion forming the magnet insertion portion” of the present invention, and the first inner periphery of the magnet insertion hole 710A. The side wall portion 712A corresponds to the “first inner peripheral side wall portion forming the magnet insertion portion” of the present invention. Further, the second inner peripheral side wall portion 715A1 and the third inner peripheral side wall portion 715A2 of the magnet insertion hole 710A correspond to the “second inner peripheral side wall portion forming the second portion of the gap” of the present invention. The second outer peripheral side wall portion 716A2 and the third outer peripheral side wall portion 716A3 of the magnet insertion hole 710A correspond to the “second outer peripheral side wall portion forming the second portion of the gap” in the present invention. Further, the outer peripheral side end wall portions 753A and 754A of the permanent magnet 750A correspond to the “outer peripheral side end wall portion of the permanent magnet” of the present invention.

A rotor 800 constituting a permanent magnet electric motor according to a fifth embodiment of the present invention will be described with reference to FIGS. 9 and 10. 9 is a cross-sectional view showing a schematic configuration of the rotor 800, and FIG. 10 is a partially enlarged view of FIG. In the rotor 800 of this embodiment, the magnet insertion hole and the permanent magnet are arranged in a trapezoidal shape with the center protruding in the direction of the rotation center O.
In the rotor 800 of this embodiment, magnet insertion holes 810A to 810D are formed in the main magnetic pole portions [A] to [D], and the first permanent magnets 850A1 to 850D1 and the second permanent magnets are inserted into the magnet insertion holes 810A to 810D, respectively. Permanent magnets 850A2 to 850D2 and third permanent magnets 850A3 to 850D3 are inserted.
Since the main magnetic pole portions [A] to [D] have the same configuration, the configuration of the main magnetic pole portion [A] will be described below with reference to FIG.

The magnet insertion hole 810A includes a first outer peripheral side wall 811A1, a first inner peripheral side wall 812A1, a second outer peripheral side wall 813A2, a second inner peripheral side wall 814A2, a third outer peripheral side wall 813A3, and a third. Inner peripheral side wall part 814A3, first outer peripheral side end wall part 815A2, fourth inner peripheral side wall part 816A2, fourth outer peripheral side wall part 817A2, first connecting end wall part 818A2, second outer peripheral side end It has a wall portion 815A3, a fifth inner peripheral side wall portion 816A3, a fifth outer peripheral side wall portion 817A3, and a second connecting end wall portion 818A3.
The first outer peripheral side wall 811A1 and the first inner peripheral side wall 812A1 extend in parallel in a direction orthogonal to the d-axis.
The second outer peripheral side wall portion 813A2 and the second inner peripheral side wall portion 814A2 are respectively on one side of the first outer peripheral side wall portion 811A1 and the first inner peripheral side wall portion 812A1 along the circumferential direction (the left side in FIG. 10). ), And extends in parallel along the q-axis of the auxiliary magnetic pole part (in FIG. 10, auxiliary magnetic pole part [DA]) adjacent to one side along the circumferential direction.
The first outer peripheral side end wall portion 815A2 is connected to the outer peripheral side end portion of the second inner peripheral side wall portion 814A2, and extends in the central direction of the main magnetic pole portion (d-axis direction) along the circumferential direction. . The fourth inner peripheral side wall portion 816A2 and the fourth outer peripheral side wall portion 817A2 are respectively an end portion on the outer peripheral side of the second outer peripheral side wall portion 813A2 and a main magnetic pole center side (d axis) of the first outer peripheral side end wall portion 815A2. Side end), and extends in the central direction of the main magnetic pole portion along the circumferential direction. The first connecting end wall portion 818A2 is connected to the ends of the fourth inner peripheral side wall portion 816A2 and the fourth outer peripheral side wall portion 817A2 on the center side of the main magnetic pole portion, and extends along the radial direction. .
The third outer peripheral side wall portion 813A3 and the third inner peripheral side wall portion 814A3 are the other sides of the first outer peripheral side wall portion 811A1 and the first inner peripheral side wall portion 812A1 along the circumferential direction (the right side in FIG. 10). ) And extends in parallel along the q axis of the auxiliary magnetic pole portion (auxiliary magnetic pole portion [AB] in FIG. 10) adjacent to the other side along the circumferential direction.
The second outer peripheral side end wall portion 815A3 is connected to the outer peripheral side end portion of the third inner peripheral side wall portion 814A3, and extends in the central direction of the main magnetic pole portion (d-axis direction) along the circumferential direction. . The fifth inner peripheral side wall portion 816A3 and the fifth outer peripheral side wall portion 817A3 are respectively arranged on the outer peripheral side end portion of the third outer peripheral side wall portion 813A3 and the main magnetic pole center side (d-axis) of the second outer peripheral side end wall portion 815A3. Side end) and extends in the main pole center direction along the circumferential direction. The second connecting end wall portion 818A3 is connected to ends of the fifth inner peripheral side wall portion 816A3 and the fifth outer peripheral side wall portion 817A3 on the center side of the main magnetic pole portion, and extends along the radial direction. .

In the present embodiment, the first outer peripheral side wall 811A1, the first inner peripheral side wall 812A1, the second outer peripheral side wall 813A2, the second inner peripheral side wall 814A2, the third outer peripheral side wall 813A3, and the third A magnet insertion portion into which the permanent magnet (first to third permanent magnets 850A1 to 850A3) is inserted is formed by the inner peripheral side wall portion 814A3.
The second outer peripheral side wall portion 813A2, the second inner peripheral side wall portion 814A2, the first outer peripheral side end wall portion 815A2, the fourth inner peripheral side wall portion 816A2, the fourth outer peripheral side wall portion 817A2, and the first connection. A first gap 841A1 is formed between the outer peripheral side end wall portion 854A2 of the second permanent magnet 850A2 and the outer peripheral surface 800a of the rotor 800 by the end wall portion 818A2. The second outer peripheral side wall portion 813A2, the second inner peripheral side wall portion 814A2 and the first outer peripheral side end wall portion 815A2 form the first portion of the first gap 841A1, and the fourth inner peripheral side wall. The second portion of the first gap 841A1 is formed by the portion 816A2, the fourth outer peripheral side wall portion 817A2, and the first connecting end wall portion 818A2.
Similarly, the third outer peripheral side wall 813A3, the third inner peripheral side wall 814A3, the second outer peripheral side end wall 815A3, the fifth inner peripheral side wall 816A3, the fifth outer peripheral side wall 817A3 and the second A second gap 841A2 is formed between the outer peripheral side end wall 854A3 of the third permanent magnet 850A3 and the outer peripheral surface 800a of the rotor 800 by the connecting end wall 818A3. The third outer peripheral side wall portion 813A3, the third inner peripheral side wall portion 814A3, and the second outer peripheral side end wall portion 815A3 form a first portion of the second gap 841A2, and the fifth inner peripheral side wall. A second portion of the second gap 841A2 is formed by the portion 816A3, the fifth outer peripheral side wall portion 817A3, and the second connecting end wall portion 818A3.

  In the present embodiment, the second outer peripheral side wall portion 813A2 and the third outer peripheral side wall portion 813A3 of the magnet insertion hole 810A correspond to the “first outer peripheral side wall portion forming the magnet insertion portion” of the present invention. The second inner peripheral side wall portion 814A2 and the third inner peripheral side wall portion 814A3 of the hole 810A correspond to the “first inner peripheral side wall portion forming the magnet insertion portion” of the present invention. Further, the fourth inner peripheral side wall portion 816A2 and the fifth inner peripheral side wall portion 816A3 of the magnet insertion hole 810A correspond to the “second inner peripheral side wall portion forming the second portion of the gap” of the present invention. The fourth outer peripheral side wall portion 817A2 and the fifth outer peripheral side wall portion 817A3 of the magnet insertion hole 810A correspond to the “second outer peripheral side wall portion forming the second portion of the gap” of the present invention. The outer peripheral side end wall portion 854A2 of the second permanent magnet 852A2 and the outer peripheral side end wall portion 854A3 of the third permanent magnet 850A3 correspond to the “outer peripheral side end wall portion of the permanent magnet” of the present invention.

The present invention is not limited to the configuration described in the embodiment, and various changes, additions, and deletions are possible.
The present invention only needs to satisfy [38 degrees ≦ θ ≦ 44 degrees] and [0.7 ≦ (L / N) ≦ 1.0]. Other configurations may be used as appropriate, or a combination of one or more may be used, or may be omitted.
The number of magnet insertion holes formed in the main magnetic pole portion, the number of permanent magnets inserted into the magnet insertion holes, the cross-sectional shape, and the like can be appropriately changed within a range in which both magnet torque and reluctance torque can be used.
The shape of the air gap provided between the outer peripheral side end wall portion of the permanent magnet inserted into the magnet insertion hole and the outer peripheral surface of the rotor can be changed as appropriate. In addition, as a method of providing a gap, a method of forming a gap in the magnet insertion hole or a method of forming a hole between the magnet insertion hole and the outer peripheral surface of the rotor can be appropriately selected and used.
When it is necessary to position the permanent magnet at a predetermined position in the magnet insertion hole, a method for providing a positioning projection on at least one wall of the magnet insertion hole, or at least one wall of the magnet insertion hole A method of providing a stepped portion for positioning can be appropriately selected and used.

200 Permanent magnet motor 210 Rotating shaft 300 Stator 311 Yoke 312 Teeth 312a Teeth base 312b Teeth tip 312c Teeth tip surface 400, 500, 600, 700, 800 Rotors 400a, 500a, 600a, 700a, 800a Outer circumferential surfaces 410A1, 410A2 410B1, 410B2, 410C1, 410C2, 410D1, 410D2, 510A1, 510A2, 510B1, 510D2, 610A1, 610A2, 610B1, 610D2, 710A, 710B, 710C, 710D, 810A, 810B, 810C, 810A 411A2-417A2, 411B1-417B1, 411D2-417D2, 511A1-514A1, 511A2-514A2, 5 1B1 to 514B1, 511D2 to 514D2, 521A1 to 526A1, 521A2 to 526A2, 521B1 to 526B1, 521D2 to 526D2, 611A1 to 618A1, 611A2 to 618A2, 611B1 to 618B1, 611D2 to 618D2, 711A, 712A, 713A1 717A2, 711B, 712B, 713B1 to 717B1, 711D, 712D, 713D2 to 717D2, 811A1, 812A1, 813A2 to 818A2, 813A3 to 818A3, 811B1, 812B1, 813B2 to 818B2, 811D3, 812D1 to 812D1 531A, 631A Central bridge part 432A-432D, 433A-433D, 532A- 35A, 532B, 534B, 533A, 533D, 535D, 632A, 633A, 632B, 633D, 731A to 731D, 732A to 732D, 831A to 831D, 832A to 832D Outer bridge portions 441A1 to 441D1, 441A2 to 441D2, 442A1 to 442D1 442A2 to 442D2, 541A1, 541A2, 541B1, 541D2, 542A1, 542A2, 542B1, 542D2, 641A1, 641A2, 641B1, 641D2, 642A1, 642A2, 642B1, 642D1, 741A841841 841D2 Gaps 450A1 to 450D1, 450A2 to 450D2, 550A1, 550A2, 550B1, 55 0D2, 650A1, 650A2, 650B1, 650D2, 750A to 750D, 850A1 to 850D1, 850A2 to 850D2, 850A3 to 850D3 Permanent magnets 451A1 to 454A1, 451A2 to 454A2, 451B1 to 454A2, 451D2 to 454A5, 451D2 to 454A2 , 551B1 to 554B1, 551D2 to 554D2, 611A1 to 65A1, 611A2 to 654A2, 651B1 to 654B1, 651D2 to 654D2, 711A to 754A, 751B to 753B, 751D, 752D, 754D, 851A1 to 854A3, 851A858 , 851B1 to 853B1, 851D1, 852D2, 854D1, 851D3 to 854D3 Part 418A1,418A2,418B1,418D2,718A1,718A2,718B1,718D2 projection 542A1,542A2,542B1,542D2 hole

Claims (10)

A stator and a rotor arranged rotatably inside the stator via a gap; the rotors are alternately arranged along a circumferential direction when viewed in a cross section perpendicular to the axial direction; A permanent magnet electric motor having a main magnetic pole part and an auxiliary magnetic pole part, wherein the main magnetic pole part is provided with a magnet insertion hole, and a permanent magnet is inserted into the magnet insertion hole,
The magnet insertion hole has a magnet insertion part formed by a first outer peripheral side wall part and a first inner peripheral side wall part arranged closer to the rotation center side than the first outer peripheral side wall part,
The rotor has a gap between the outer peripheral side end wall portion of the permanent magnet inserted into the magnet insertion hole and the outer peripheral surface of the rotor,
The gap has a first portion facing the outer peripheral end wall portion of the permanent magnet, and a second portion extending from the first portion toward the center of the main magnetic pole portion, and the second portion The portion is formed by a second outer peripheral side wall and a second inner peripheral side wall disposed on the rotation center side from the second outer peripheral side wall,
The first outer periphery when the angle formed by the first outer peripheral side wall portion and the second inner peripheral side wall portion is θ and the second inner peripheral side wall portion is projected onto the first outer peripheral side wall portion. The length along the extending direction of the side wall portion is N, and the outer circumference of the permanent magnet from the position where the end of the second inner peripheral side wall portion on the center side of the main magnetic pole portion is projected onto the first outer peripheral side wall portion. When the length to the side end wall portion is L, [38 degrees ≦ θ ≦ 44 degrees] and [0.7 ≦ (L / N) ≦ 1.0] are satisfied. Characteristic permanent magnet motor. The electric motor according to claim 1,
When the width of the gap is G, the thickness of the permanent magnet is H, and the distance between the second outer peripheral side wall and the second inner peripheral side wall is S, [G ≦ S ≦ H] is satisfied. A permanent magnet motor characterized by being configured as described above. The permanent magnet motor according to claim 1 or 2,
A permanent magnet electric motor configured to satisfy [H ≦ L]. The permanent magnet motor according to any one of claims 1 to 3,
A permanent magnet electric motor configured to satisfy [0.4 mm ≦ T ≦ 1.0 mm], where T is a minimum value of the gap between the gap and the outer peripheral surface of the rotor. The permanent magnet electric motor according to any one of claims 1 to 4,
The permanent magnet electric motor according to claim 1, wherein the gap is provided inside the magnet insertion hole. The permanent magnet electric motor according to any one of claims 1 to 4,
The permanent magnet motor according to claim 1, wherein the gap is provided between the magnet insertion hole and an outer peripheral surface of the rotor. The permanent magnet motor according to any one of claims 1 to 6,
The magnet insertion hole has a first magnet insertion hole and a second magnet insertion hole formed on both sides of a central bridge portion, and the permanent magnet includes the first magnet insertion hole and the first magnet insertion hole. A permanent magnet electric motor having a first permanent magnet and a second permanent magnet inserted into the two magnet insertion holes. The permanent magnet motor according to any one of claims 1 to 7,
The permanent magnet motor is characterized in that the magnet insertion holes are arranged in a V shape with the center protruding in the direction of the rotation center. The permanent magnet motor according to any one of claims 1 to 7,
The permanent magnet motor is characterized in that the magnet insertion holes are linearly arranged along a circumferential direction. The permanent magnet motor according to any one of claims 1 to 7,
The permanent magnet motor is characterized in that the magnet insertion hole is arranged in a trapezoidal shape with the center protruding in the direction of the rotation center.

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