JP2023012609A - Permanent magnet type rotary electric machine, and positioning structure for magnet - Google Patents

Abstract

To provide a permanent magnet type rotary electric machine in which positioning of a magnet is enhanced.SOLUTION: A permanent magnet type rotary electric machine is provided, comprising a stator and a rotor disposed in radial outside of the stator. The rotor includes: a rotor yoke opposed with the stator with a gap interposed therebetween; a permanent magnet disposed on an opposite face opposed with the stator in faces of the rotor yoke; and a plate member positioning the permanent magnet in a circumferential direction. The opposite face includes a slit which is recessed radially outside. The plate member includes a fitting portion which is fitted into the slit and of which the circumferential position is fixed, and a projection protruding to radial inside from the fitting portion, a circumferential end of the permanent magnet is in contact with the projection.SELECTED DRAWING: Figure 3

Description

The present invention relates to a permanent magnet type rotating electric machine and a magnet positioning structure.

2. Description of the Related Art Conventionally, there is known a permanent magnet type rotating electric machine, which is an outer rotor type rotating electric machine, in which permanent magnets are fixed to an inner peripheral surface of a rotor facing a stator. Patent Document 1 discloses a structure in which a magnet holder made of a non-magnetic material such as resin is processed into a shape into which a permanent magnet fits, and the permanent magnet is positioned by the magnet holder.

Japanese Patent No. 6326662

However, in Patent Document 1, since a magnet holder made of a non-magnetic material such as resin is used, there is a problem with the strength of the magnet holder. For this reason, it is not possible to increase the fastening force of the screws that fix the magnet holders. There is a possibility that the force applied to the magnet in the circumferential direction resists the tightening force of the screw and moves the magnet holder in the circumferential direction. In addition, the production of resin parts required the production of expensive molds, and each time the dimensions and shape were to be changed, it was necessary to produce molds. For this reason, conventionally, there has been room for improvement in the positioning of the magnets.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a permanent magnet rotating electrical machine with improved magnet positioning.

A permanent magnet type rotating electric machine according to an aspect of the present invention is a permanent magnet type rotating electric machine including a stator and a rotor disposed radially outside the stator, wherein the rotor is separated from the stator by a gap. a rotor yoke facing the rotor yoke, permanent magnets disposed on a surface of the rotor yoke facing the stator, and a plate member for positioning the permanent magnet in the circumferential direction, the facing surface being , a slit recessed radially outward, and the plate member includes a fitting portion fitted in the slit and fixed in circumferential position, and a convex portion protruding radially inward from the fitting portion. And, the permanent magnet is in contact with the projection at its circumferential end.

In the permanent magnet type rotating electric machine of one aspect described above, the fitting portion is fixed to the rotor yoke by an axially extending pin.

In the permanent magnet type rotating electrical machine of one aspect described above, the facing surface is positioned radially inward of the fitting portion.

In the permanent magnet type rotating electric machine of one aspect described above, the radially inner surface of the permanent magnet is located radially inward of the convex portion.

A magnet positioning structure according to an aspect of the present invention is a magnet positioning structure for positioning a permanent magnet on an inner peripheral surface of an annular rotor yoke, comprising a plate member for positioning a circumferential position of the permanent magnet, The inner peripheral surface of the rotor yoke has a slit that is recessed radially outward, and the plate member includes a fitting portion that is fitted in the slit and fixed in position in the circumferential direction, and a fitting portion that protrudes radially inward from the fitting portion. The permanent magnet is positioned by contacting the circumferential end of the permanent magnet with the convex portion.

According to one aspect of the present invention, it is possible to provide a permanent magnet type rotating electrical machine with improved magnet positioning.

1 is a perspective view of a motor according to a first embodiment of the invention; FIG. It is a side cross section of the motor 10 of 1st Embodiment. It is a figure shown inclined so that a bottom face may be seen with respect to the side view of the motor 10 of 1st Embodiment. FIG. 2 is a side cross-sectional view showing the motor 10 of the first embodiment cut along a plane passing through the pin 30 and parallel to the axial direction, showing an enlarged view of the vicinity of the pin 30. FIG. It is a figure which extracts and shows the permanent magnet 19 and the board member 20 of FIG. 6 is a perspective view of the permanent magnet 19 and plate member 20 of FIG. 5 as viewed from the -Y side; FIG.

A permanent magnet type rotating electric machine according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that, in the drawings below, in order to make each configuration easier to understand, there are cases where the scale, number, etc., of the actual structure and each structure are different.

Also, in the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is parallel to the axial direction of the central axis J shown in FIG. The X-axis direction is the left-right direction in FIG. The Y-axis direction is a direction orthogonal to both the Z-axis direction and the X-axis direction. In any of the X-axis direction, Y-axis direction, and Z-axis direction, the side indicated by the arrows in the drawing is the + side, and the opposite side is the - side.

Also, in the following description, the positive side (+Z side) in the Z-axis direction is called "one side", and the negative side (-Z side) in the Z-axis direction is called "the other side". Note that the terms "one side" and "the other side" are merely names used for explanation, and do not limit the actual positional relationship and direction. Further, unless otherwise specified, the direction parallel to the central axis J (the Z-axis direction) is simply referred to as the "axial direction", the radial direction about the central axis J is simply referred to as the "radial direction", and the central axis J , that is, the circumference of the central axis J is simply referred to as the "circumferential direction". The side closer to the central axis J in the radial direction is called "radial inner side", and the side farther from the central axis J is called "radial outer side".

In this specification, "extends in the axial direction" means not only the case of extending strictly in the axial direction (Z-axis direction), but also the case of extending in a direction inclined within a range of less than 45° with respect to the axial direction. Also includes In addition, in this specification, "extending in the radial direction" means extending strictly in the radial direction, that is, in a direction perpendicular to the axial direction (the Z-axis direction), and in addition to extending in the radial direction by 45 It also includes cases where it extends in a tilted direction within a range of less than °. "Parallel" includes not only the case of being strictly parallel, but also the case of being tilted within a range of less than 45°.

<First embodiment>
FIG. 1 is a perspective view of a motor according to a first embodiment of the invention. A motor 10 in FIG. 1 is an example of a permanent magnet rotating electric machine. FIG. 2 is a side cross section of the motor 10 of the first embodiment. In FIG. 1, illustration of the fixed shaft 13 and the bearings 14 and 15 is omitted.

The motor 10 has a fixed shaft 13 extending along the central axis J, a stator 12, and a rotor 11 arranged radially outside the stator 12 with a gap therebetween. Since the configuration of the stator 12 is not the main part of the present invention, the detailed configuration of the stator 12 is omitted. The fixed shaft 13 is fixed to the stator 12, for example. The rotor 11 has a hollow shaft portion 16 radially inward. The fixed shaft 13 passes through the hollow shaft portion 16 . The rotor 11 is supported by the fixed shaft 13 via bearings 14 and 15 so as to be rotatable around the central axis J. As shown in FIG.

The rotor 11 has a rotor yoke 17 facing the stator 12 with a gap therebetween. The rotor yoke 17 is an annular member. The rotor yoke 17 is formed of a laminated steel plate obtained by laminating electromagnetic steel plates in the axial direction. The rotor yoke 17 may be formed by hollowing out an iron core instead of laminated steel plates. The rotor 11 has permanent magnets 19 (see FIG. 3). A permanent magnet 19 is fixed to the inner peripheral surface 18 a of the rotor yoke 17 . The rotor yoke 17 has an inner peripheral surface 18a and an inner peripheral surface 18b. The inner peripheral surface 18 a is an example of a facing surface that faces the stator 12 . The inner peripheral surface 18b is positioned radially inward of the inner peripheral surface 18a. One axial end of the permanent magnet 19 may be in contact with the radial step between the inner peripheral surface 18b and the inner peripheral surface 18a.

FIG. 3 is a side view of the motor 10 of the first embodiment tilted so that the bottom surface can be seen. An inner peripheral surface 18a of the rotor yoke 17 has a slit 18c recessed radially outward. The slit 18c is formed along the entire circumference of the inner peripheral surface 18a. The slit 18c may be formed by cutting using a lathe or the like. The slit 18c may be formed by laminating electromagnetic steel sheets with an electromagnetic steel sheet having an inner diameter larger than that of the inner peripheral surface 18a sandwiched at an axial position where the slit 18c is desired to be formed.

The rotor 11 has a plate member 20 . It fits into the slit 18 c of the rotor yoke 17 . The plate member 20 positions the permanent magnet 19 in the circumferential direction. The permanent magnets 19 are arranged over the entire circumference, but only five permanent magnets 19 are shown in FIG. Although the plate members 20 are arranged over the entire circumference in the circumferential direction, only three plate members 20 are illustrated in FIG. The rotor yoke 17 has a through hole 11a into which a pin 30 for fixing the plate member 20 fitted in the slit 18c is inserted. The through hole 11a extends axially.

FIG. 4 is a side cross-sectional view showing the motor 10 of the first embodiment cut along a plane passing through the pin 30 and parallel to the axial direction, showing an enlarged view of the vicinity of the pin 30. FIG. The through hole 11a penetrates from the other axial end of the rotor yoke 17 to the slit 18c. The through-hole 11a may further extend from the slit 18c to one side of the rotor yoke 17 in the axial direction. The plate member 20 has a through hole 20c extending in the axial direction. By fitting the plate member 20 into the slit 18c, the through hole 11a and the through hole 20c are communicated with each other. The plate member 20 is fixed to the slit 18c by fitting the pin 30 into the communicating through hole 11a and through hole 20c.

FIG. 5 is a diagram showing the permanent magnet 19 and the plate member 20 extracted from FIG. FIG. 6 is a perspective view of the permanent magnet 19 and plate member 20 of FIG. 5 viewed from the -Y side. The permanent magnet 19 has a cubic shape. Of the surfaces of the permanent magnet 19 , a surface 19 a that is a radially inner surface faces the stator 12 . Of the surfaces of the permanent magnet 19 , a surface 19 b that is a radially outer surface faces the inner peripheral surface 18 a of the rotor yoke 17 .

The plate member 20 has a fitting portion 20a and a convex portion 20b protruding radially inward from the fitting portion 20a. The fitting portion 20a is a flat member. The axial width of the slit 18c is substantially equal to the axial thickness of the plate member 20, and the fitting portion 20a fits into the slit 18c. The fitting portion 20a has a through hole 20c extending therethrough in the axial direction. In this embodiment, one plate member 20 has three protrusions 20b. The number of protrusions 20b provided on one plate member 20 may be other than three. In this embodiment, one plate member 20 has two through holes 20c. The number of through holes 20c provided in one plate member 20 may be other than two. The fitting portion 20a is fixed in its circumferential position by inserting a pin through the through hole 11a and the through hole 20c of the rotor yoke 17 while being fitted in the slit 18c. The fitting portion 20a in the slit 18c and the rotor yoke 17 may be screwed together. The pin that communicates the through-hole 11a and the through-hole 20c is preferably a pin that contacts the through-hole 11a and the through-hole 20c without a gap. For example, a parallel pin or a knock pin can be used.

The circumferential length between a certain convex portion 20b and another convex portion 20b adjacent to this certain convex portion 20b in the circumferential direction is approximately equal to the circumferential length of the permanent magnet 19, and the permanent magnet 19 is It fits between the convex portions 20b. The permanent magnet 19 has its circumferential end fixed by contacting the projection 20b.

In the plate member 20 of this embodiment, one plate member 20 positions three permanent magnets 19, and a certain plate member 20, this certain plate member 20, and another plate member 20 are arranged in the circumferential direction. In this case, the convex portion 20b closest to another plate member 20 among the convex portions 20b of a certain plate member 20 and the convex portion 20b closest to the certain plate member 20 among the convex portions 20b of another plate member 20 One permanent magnet 19 can be arranged and positioned between them. At this time, the circumferential length from the circumferentially outermost convex portion 20b of the convex portions 20b of the plate member 20 to the circumferential end of the fitting portion 20a on the side closer to the convex portion 20b is equal to that of the permanent magnet 19. It is 1/2 or less of the length in the circumferential direction.

The plate member 20 is, for example, sheet metal. Therefore, the fastening force between the fitting portion 20a and the rotor yoke 17 can be increased. If the plate member 20 is made of a non-magnetic material, the permeance of the magnet in the plate member 20 portion is lowered and the magnetic flux density is lowered. The material of the plate member 20 is, for example, SPHC. The plate member 20 is desirably made of a material that satisfies the strength (stress, surface pressure) against the force applied to the plate member 20 .

The inner peripheral surface 18a of the rotor yoke 17 is positioned radially inward of the fitting portion 20a. Alternatively, the fitting portion 20a does not protrude radially inward from the inner peripheral surface 18a. This makes it easy to fix the permanent magnet 19 to the inner peripheral surface 18a with an adhesive.

A surface 19a, which is a radially inner surface of the permanent magnet 19, is positioned radially inward of the convex portion 20b. Alternatively, the convex portion 20 b does not protrude radially inward from the surface 19 a of the permanent magnet 19 . As a result, the projections 20b do not protrude into the gap between the rotor 11 and the stator 12. As shown in FIG. The amount by which the convex portion 20b protrudes radially inward from the inner peripheral surface 18a is set to a protrusion amount that satisfies the strength (stress, surface pressure) required to fix the circumferential position of the permanent magnet 19 . If the length of the protrusion 20b extending radially inward is lengthened, the magnetic flux leakage increases and the magnetic flux density in the gap decreases because the plate member 20 is made of a magnetic material. Therefore, it is desirable that the radial length of the convex portion 20b be the minimum height within a range that satisfies the mechanical strength.

In manufacturing the rotor 11 of this embodiment, first, the slit 18c is formed in the annular rotor yoke 17. As shown in FIG. Subsequently, the plate member 20 is fitted into the slit 18c and fixed with a pin. Subsequently, an adhesive is applied to the inner peripheral surface 18a of the rotor yoke 17, the permanent magnets 19 are positioned with reference to the protrusions 20b of the plate member 20, and the permanent magnets 19 are adhered and fixed to the inner peripheral surface 18a.

According to the present embodiment, the time required to form the slit 18c is short, and the processing time can be shortened. Further, according to this embodiment, the plate member 20 can be manufactured relatively easily by, for example, laser processing. Further, according to the present embodiment, the part for determining the position of the permanent magnet 19 is the plate member 20 made of sheet metal, so that a mold such as resin molding is not required, and the mold manufacturing cost, size and shape can be changed. There is no cost to do so. Further, according to this embodiment, since the plate member 20 is held by the rotor yoke 17 by the pin, the plate member 20 does not move when receiving the motor torque.

The present invention is not limited to the above embodiments, and various improvements and design changes may be made without departing from the scope of the present invention. In addition, the embodiments disclosed this time should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning of equivalents to the scope of the claims.

DESCRIPTION OF SYMBOLS 10... Motor 11... Rotor 12... Stator 13... Fixed shaft 17... Rotor yoke 18c... Slit 19... Permanent magnet 20... Plate member

A permanent magnet type rotating electric machine according to an aspect of the present invention is a permanent magnet type rotating electric machine including a stator and a rotor disposed radially outside the stator, wherein the rotor is separated from the stator by a gap. a rotor yoke facing the rotor yoke, permanent magnets disposed on a surface of the rotor yoke facing the stator, and a plate member for positioning the permanent magnet in the circumferential direction, the facing surface being , a slit recessed radially outward, and the plate member includes a fitting portion fitted in the slit and fixed in circumferential position, and a convex portion protruding radially inward from the fitting portion. The permanent magnet has a circumferential end in contact with the projection, and one axial end of the projection is located on the other axial side of the one axial end of the permanent magnet. The other axial end of the protrusion is located on the one axial side of the other axial end of the permanent magnet.

A magnet positioning structure according to an aspect of the present invention is a magnet positioning structure for positioning a permanent magnet on an inner peripheral surface of an annular rotor yoke, comprising a plate member for positioning a circumferential position of the permanent magnet, The inner peripheral surface of the rotor yoke has a slit that is recessed radially outward, and the plate member includes a fitting portion that is fitted in the slit and fixed in position in the circumferential direction, and a fitting portion that protrudes radially inward from the fitting portion. The permanent magnet is positioned by contacting the circumferential end of the permanent magnet with the convex portion, and the one axial end of the convex portion is positioned further from the one axial end of the permanent magnet. is positioned on the other side in the axial direction, and the other end in the axial direction of the projection is positioned on the one side in the axial direction relative to the other end in the axial direction of the permanent magnet.

Claims (5)

A permanent magnet type rotating electric machine having a stator and a rotor disposed radially outward of the stator,
The rotor includes a rotor yoke facing the stator with a gap therebetween, permanent magnets disposed on a surface of the rotor yoke facing the stator, and plate members for positioning the permanent magnets in the circumferential direction. , has
The facing surface has a slit recessed radially outward,
The plate member has a fitting portion fitted in the slit and fixed in a circumferential position, and a convex portion protruding radially inward from the fitting portion,
The permanent magnet is in contact with the projection at its circumferential end.
Permanent magnet rotating electric machine. The fitting portion is fixed to the rotor yoke by an axially extending pin.
The permanent magnet type rotary electric machine according to claim 1. The facing surface is positioned radially inward of the fitting portion,
The permanent magnet type rotating electric machine according to claim 1 or 2. the radially inner surface of the permanent magnet is located radially inwardly of the convex portion;
The permanent magnet type rotary electric machine according to any one of claims 1 to 3. A magnet positioning structure for positioning a permanent magnet on the inner peripheral surface of an annular rotor yoke,
Having a plate member for positioning the circumferential position of the permanent magnet,
an inner peripheral surface of the rotor yoke has a slit recessed radially outward,
The plate member has a fitting portion fitted in the slit and fixed in a circumferential position, and a convex portion protruding radially inward from the fitting portion,
The permanent magnet is positioned by having its circumferential end in contact with the convex portion.
Magnet positioning structure.

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