WO2018163319A1

WO2018163319A1 - Rotor and rotating electric machine provided with said rotor

Info

Publication number: WO2018163319A1
Application number: PCT/JP2017/009235
Authority: WO
Inventors: 龍吉木嶋
Original assignee: 三菱電機株式会社
Priority date: 2017-03-08
Filing date: 2017-03-08
Publication date: 2018-09-13

Abstract

This rotor is provided with: a rotor core formed by stacking a plurality of steel plates in the axial direction of a rotating shaft, and having a plurality of magnet insertion holes that penetrate in the axial direction of the rotating shaft; permanent magnets inserted into the magnet insertion holes; and an end plate disposed on an end surface in the axial direction of the rotating shaft of the rotor core. A pressing part that presses the permanent magnets in the axial direction of the rotating shaft while in contact with an end part of the permanent magnets inserted in the permanent magnet insertion holes is formed on the steel plate disposed on one end section side or on the other end section side of the rotor core.

Description

Rotor and rotary electric motor equipped with the rotor

The present invention relates to a rotor and a rotary electric motor including the rotor.

Rotating motors are known to have an annular stator that is fixedly supported by shrink fitting or the like on the inner wall surface of a sealed container, and a rotor that is rotatably attached to the inner side surface of the stator. The rotor has a rotor core formed by stacking a plurality of electromagnetic steel sheets punched into a predetermined shape, permanent magnets inserted into a plurality of magnet insertion holes formed in the rotor core, and both end surfaces of the rotor core in the rotation axis direction. And an arranged end plate.

In the above-described embedded magnet type rotor, the size of the magnet insertion hole is designed to be larger than the dimension of the permanent magnet. This is for avoiding the generation of thermal stress due to temperature changes, as well as making it easier to insert the permanent magnet into the magnet insertion hole. However, in the embedded magnet type rotor, the permanent magnet moves inside the magnet insertion hole when the rotor rotates, so that the rotation balance of the rotor fluctuates and noise is generated during operation of the rotary motor.

Therefore, Patent Document 1 discloses a motor rotor having a structure in which a pressing portion that presses a permanent magnet in the rotation axis direction is formed on an end plate. The pressing portion is formed by deforming a part of the end plate so that a part thereof enters the magnet insertion hole at a position corresponding to the magnet insertion hole.

Japanese Unexamined Patent Publication No. 2016-92984

Generally, a rotor of a rotary motor is manufactured by separate processes for an electromagnetic steel plate and an end plate. Therefore, when the rotor is small, it is difficult to align the pressing portion formed on the end plate with the magnet insertion hole formed on the electromagnetic steel plate, and there is a possibility that the permanent magnet cannot be sufficiently pressed by the pressing portion. In addition, the rotary electric motor disclosed in Patent Document 1 requires a separate mold for forming the pressing portion on the end plate, which increases manufacturing costs.

The present invention has been made to solve the above-described problems, and can firmly fix the permanent magnet inserted into the magnet insertion hole of the rotor core, thereby reducing noise generated during operation of the rotary motor. An object of the present invention is to provide a rotor and a rotary electric motor including the rotor.

A rotor according to the present invention is formed by laminating a plurality of steel plates in the rotation axis direction, and has a rotor core having a plurality of magnet insertion holes penetrated in the rotation axis direction, and a permanent magnet inserted into the magnet insertion hole, An end plate disposed on an end surface of the rotor core in the rotation axis direction, and the steel plate disposed on one end side or the other end side of the rotor core is inserted into the magnet insertion hole. A pressing portion is formed in contact with the end of the permanent magnet to press the permanent magnet in the direction of the rotation axis.

According to the present invention, the steel plate in which the pressing portion that contacts the end portion of the permanent magnet inserted into the magnet insertion hole and presses in the direction of the rotation axis is disposed on one end side or the other end side of the rotor core. Therefore, the position of the permanent magnet can be firmly fixed by the pressing portion, and noise generated during operation of the rotary motor can be reduced.

It is the top view which showed the rotary electric motor provided with the rotor which concerns on Embodiment 1 of this invention. It is the longitudinal cross-sectional view which showed the rotor which concerns on Embodiment 1 of this invention. FIG. 3 is a plan view illustrating the rotor according to the first embodiment of the present invention with the end plate omitted. FIG. 4 is an enlarged cross-sectional view taken along line AA shown in FIG. 3. FIG. 5 is an enlarged cross-sectional view taken along line AA in FIG. 3 showing a modification of the rotor according to the first embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view taken along line AA in FIG. 3 showing a modification of the rotor according to the first embodiment of the present invention. It is the rotor which concerns on Embodiment 2 of this invention, and abbreviate | omitted and shown the top plate. It is the longitudinal cross-sectional view which abbreviate | omitted the end plate and was a magnet insertion hole part of the rotor which concerns on Embodiment 2 of this invention. It is the longitudinal cross-sectional view which abbreviate | omitted the end plate and was a magnet insertion hole part of the rotor which concerns on Embodiment 3 of this invention. It is the rotor provided with the magnet stopper which positions the permanent magnet inserted in the magnet insertion hole, Comprising: It is the top view which abbreviate | omitted and showed the end plate. It is the top view which expanded and showed the magnet insertion part shown in FIG. It is the top view which expanded and showed the magnet insertion part of the rotor which flatly pressed the magnet stopper and made it the press part. FIG. 10 is a longitudinal cross-sectional view showing a magnet insertion hole portion in which the end plate is omitted, which is a modification of the rotor according to the third embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is omitted or simplified as appropriate. Moreover, about the structure as described in each figure, the shape, a magnitude | size, arrangement | positioning, etc. can be suitably changed within the scope of the present invention.

Embodiment 1 FIG.
FIG. 1 is a plan view showing a rotary electric motor including a rotor according to Embodiment 1 of the present invention. FIG. 2 is a longitudinal sectional view showing the rotor according to the first embodiment. FIG. 3 is a plan view illustrating the rotor according to the first embodiment with the end plates omitted. FIG. 4 is an enlarged cross-sectional view taken along line AA shown in FIG.

As shown in FIG. 1, the rotary motor 300 is attached to an annular stator 200 fixedly supported by shrink fitting or the like on an inner wall surface of a sealed container (not shown) and rotatably attached to the inner surface of the stator 200. And the rotor 100.

The stator 200 includes a stator core 201 formed by laminating a plurality of electromagnetic steel plates made of a high permeability material in the rotation axis direction P, and windings (not shown) wound around the stator core 201. The stator core 201 includes a core back part 202 configured in an annular shape and a plurality of teeth parts 203 extending inward from the core back part 202. Note that the winding is provided by winding the conductive wire around the tooth portion 203 a plurality of times.

As shown in FIGS. 2 and 3, the rotor 100 is disposed on the rotor core 1, the permanent magnet 4 inserted in the magnet insertion hole 3 formed in the rotor core 1, and both end faces of the rotor core 1 in the rotation axis direction P. And an end plate 5 made of a non-magnetic material. In the illustrated rotor 100 according to the first embodiment, the rotor 100 is placed vertically for convenience of explanation.

The rotor core 1 is formed by laminating a plurality of electromagnetic steel plates 2 made of a high permeability material punched into an annular shape in the rotation axis direction P. Six substantially rectangular magnet insertion holes 3 are formed in the vicinity of the outer periphery of the rotor core 1 along the circumferential direction. A neodymium permanent magnet 4 is inserted (embedded) in each magnet insertion hole 3. The number of magnet insertion holes 3 is not limited to the six shown in the figure as long as the number corresponds to the number of magnetic poles.

Further, in the rotor core 1, the waveform of the counter electromotive force generated in the winding wound around the stator core 201 is brought close to a sine wave on each outer peripheral side of the magnet insertion hole 3 to suppress vibration and noise of the rotary motor 300. A plurality of slits 11 to be opened are formed. In the first embodiment, seven slits 11 are formed as an example on each outer peripheral side of the magnet insertion hole 3. Further, on the inner peripheral side of the magnet insertion hole 3, an air hole portion 12 through which discharge gas passing through the rotary electric motor 300 passes and a rivet insertion hole 13 for inserting a rivet are formed therethrough. A shaft insertion hole 10 for inserting a shaft such as a compression mechanism portion is formed through the center of the inner circumference side of the magnet insertion hole 3. For example, when the rotary electric motor 300 is incorporated in a compressor, the rotor 100 is fixed to a shaft such as a compression mechanism portion that is passed through the shaft insertion hole 10 by shrink fitting or the like.

The end plates 5 are provided on both end faces of the rotor core 1 in the rotation axis direction P as shown in FIG. Although not shown in detail, each end plate 5 is formed with a shaft insertion hole through which the shaft is inserted, an air hole portion through which the discharge gas passes through the rotary electric motor 300, and a rivet insertion hole through which the rivet is inserted. ing. That is, the rotor 100 is formed by providing end plates 5 on both end faces of the rotor core 1 to which the permanent magnets 4 are mounted, and inserting the rivets into a plurality of rivet insertion holes and caulking and fixing.

When a current is supplied to the winding of the stator 200, the rotor 100 of the rotary motor 300 rotates by receiving a rotational force from a rotating magnetic field generated by the stator 200 to which the current is supplied. Along with this, a shaft (not shown) inserted through the shaft insertion hole 10 of the rotor 100 is rotationally driven.

Here, in the above-described embedded magnet type rotor, the size of the magnet insertion hole 3 is designed to be larger than the dimension of the permanent magnet 4. This is for avoiding generation of thermal stress due to temperature change, in addition to facilitating insertion of the permanent magnet 4 into the magnet insertion hole 3. However, in the embedded magnet type rotor, the permanent magnet 4 moves inside the magnet insertion hole 3 during rotation of the rotor, so that the rotation balance of the rotor fluctuates and noise is generated during the operation of the rotary electric motor 300. .

Therefore, in the rotor 100 of the first embodiment, as shown in FIG. 3 and FIG. 4, the magnetic steel sheet 2 a arranged at the top of the plurality of electromagnetic steel sheets 2 constituting the rotor core 1 is provided in the magnet insertion hole 3. A pressing portion 6 is formed in contact with the end portion of the inserted permanent magnet 4 to press the permanent magnet downward in the rotation axis direction P.

As shown in FIGS. 3 and 4, the pressing portion 6 includes an inclined surface portion 60 inclined toward the permanent magnet 4 from the opening edge facing in the circumferential direction of the magnet insertion hole 3, and magnet insertion from the end of the inclined surface portion 60. It is formed in a pair of left and right spring plates that project toward the center of the hole 3 and have a flat surface portion 61 that contacts the end of the permanent magnet 4 and presses downward in the rotational axis direction P. That is, the pressing part 6 formed in the shape of a spring plate can strongly press the permanent magnet 4 downward in the rotation axis direction P by using the elastic force. Since the pressed permanent magnet 4 is strongly pressed against the lower end plate 5 at the lower end surface, the position in the rotation axis direction P is firmly fixed. Further, the permanent magnet 4 is strongly pressed and sandwiched between the pressing portion 6 and the end plate 5, and the movement in the direction orthogonal to the rotational axis direction P is also restricted by the action of each frictional force.

In addition, the pressing part 6 is not limited to the structure formed in the uppermost electromagnetic steel plate 2a shown in FIG. The pressing portion 6 may be formed on the electromagnetic steel sheet 2 (for example, the electromagnetic steel sheet 2 located in the second or third stage from the top) disposed in the upper part of the plurality of electromagnetic steel sheets 2 constituting the rotor core 1. .

Although not shown in detail, the pressing portion 6 is the electromagnetic steel plate 2 arranged at the lowest stage among the plurality of electromagnetic steel plates 2 constituting the rotor core 1 and is inserted into the magnet insertion hole 3. Alternatively, the permanent magnet 4 may be in contact with the end of the permanent magnet 4 and pressed upward in the rotational axis direction P. That is, since the upper end surface of the permanent magnet 4 pressed upward by the pressing portion 6 is strongly pressed against the upper end plate 5, the position in the rotation axis direction P is firmly fixed. Of course, the pressing part 6 is formed on the electromagnetic steel sheet 2 (for example, the electromagnetic steel sheet 2 located in the second or third stage from the bottom) disposed in the lower part of the plurality of electromagnetic steel sheets 2 constituting the rotor core 1. Also good.

Therefore, the rotor 100 according to the first embodiment is in contact with the end of the permanent magnet 4 inserted into the magnet insertion hole 3 on the electromagnetic steel plate 2 disposed on one end side (upper part) of the rotor core 1. Since the pressing portion 6 that presses the permanent magnet 4 in the rotation axis direction P is formed, the position of the permanent magnet 4 can be firmly fixed by the pressing portion 6, and noise generated during operation of the rotary motor 300. Can be reduced.

Further, in the rotor 100 of the first embodiment, the pressing portion 6 is inclined from the opposed opening edge of the magnet insertion hole 3 toward the permanent magnet 4 and the magnet insertion hole 3 from the end of the inclined surface portion 60. Is formed in a pair of spring plates having a flat surface portion 61 that protrudes toward the center of the permanent magnet 4 and abuts against the end portion of the permanent magnet 4 and presses in the rotational axis direction P. The permanent magnet 4 can be strongly pressed in the rotation axis direction P. Therefore, the rotor 100 according to the first embodiment can firmly fix the position of the permanent magnet 4 in the rotation axis direction P, and can more effectively reduce noise generated during the operation of the rotary electric motor 300. .

5 and 6 are enlarged cross-sectional views taken along line AA in FIG. 3, each showing a modification of the rotor according to Embodiment 1 of the present invention. As shown in FIG. 5, the pressing portion 6 may be formed on a plurality of (three in the illustrated example) electromagnetic steel sheets 2 including the uppermost stage of the rotor core 1. The rotor can strongly press the permanent magnet 4 downward in the rotation axis direction P by the elastic force of the plurality of pressing portions 6.

Further, the rotor 100 shown in FIG. 6 has a configuration in which the permanent magnet 4 is divided into a plurality of parts in order to reduce magnet eddy current loss. The permanent magnet 4 shown in FIG. 6 is composed of two pieces that are divided in the circumferential direction of the rotor core 1. The pair of left and right pressing portions 6 are configured to press each of the two

permanent magnets

4 and 4 into which the respective pressing portions are divided downward in the rotation axis direction P. Therefore, even if the rotor 100 is composed of the two permanent magnets 4 divided to reduce the magnet eddy current loss, the pair of pressing portions 6 press the permanent magnet 4 to be strong. Since it can fix, the noise which generate | occur | produces during the driving | operation of the rotary electric motor 300 can be reduced. The two permanent magnets 4 inserted into the magnet insertion hole 3 repel each other inside the magnet insertion hole 3 and are pressed against the inner surface of the magnet insertion hole 3. Therefore, each permanent magnet 4 is not fixed obliquely with respect to the rotation axis direction P.

Embodiment 2. FIG.
Next, a rotor according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 7 is a plan view showing the rotor according to the second embodiment with the end plates omitted. FIG. 8 is a longitudinal sectional view showing a magnet insertion hole portion of the rotor according to the second embodiment, with the end plate omitted. In addition, the same code | symbol is attached | subjected about the structure same as the rotor demonstrated in Embodiment 1, and the description is abbreviate | omitted suitably.

7 and 8, the rotor of the second embodiment includes four permanent magnets 4 divided in the circumferential direction of the rotor core 1 in order to reduce magnet eddy current loss. The electromagnetic steel sheet 2 arranged at the uppermost stage of the rotor core 1 is formed with a pressing portion 7 that contacts the end of the permanent magnet 4 and presses the permanent magnet 4 downward in the rotation axis direction P.

As shown in FIG. 7, the pressing portion 7 is formed in a zigzag shape from one opening edge facing in the circumferential direction of the magnet insertion hole 3 toward the other opening edge as seen from the rotation axis direction P. As shown in FIG. 8, the cross-sectional shape is also formed in a zigzag shape. As shown in FIG. 8, the pressing portion 7 has four protrusions 70 protruding toward the permanent magnet 4. Each protrusion 70 of the pressing portion 7 abuts against an end portion of each corresponding permanent magnet 4 to press the permanent magnet 4 downward in the rotation axis direction P. Further, the pressing portion 7 can be secured in length by being formed in a zigzag shape when viewed from the rotation axis direction P, and the permanent magnet 4 can be strongly pushed in the rotation axis direction P.

Therefore, in the rotor according to the second embodiment, even if the permanent magnet 4 is constituted by a plurality (for example, three or more) divided in the circumferential direction of the rotor core 1 in order to reduce magnet eddy current loss. The plurality of permanent magnets 4 can be pressed and firmly fixed by the pressing portion 7, and noise generated during operation of the rotary electric motor 300 can be reduced. The plurality of permanent magnets 4 inserted into the magnet insertion hole 3 repel each other inside the magnet insertion hole 3, and the permanent magnets 4 at the left and right ends are pressed against the inner surface of the magnet insertion hole 3. Therefore, each permanent magnet 4 is not fixed obliquely with respect to the rotation axis direction P.

Note that the zigzag-shaped pressing portion 7 may have a configuration in which a single permanent magnet 4 is pressed downward in the rotation axis direction P with two or more protrusions 70, for example. Moreover, the zigzag-shaped pressing part 7 is not limited to the structure which has the four protrusions 70 shown in figure. The zigzag-shaped pressing portion 7 may be configured to have a number of protrusions corresponding to the number of divided permanent magnets 4. Further, the zigzag-shaped pressing portion 7 is formed on the electromagnetic steel sheet 2 (for example, the electromagnetic steel sheet 2 located in the second or third stage from the top) disposed in the upper part of the plurality of electromagnetic steel sheets 2 constituting the rotor core 1. The formed structure may be sufficient. Further, the zigzag pressing portion 7 may be formed on the electromagnetic steel plate 2 disposed in the lower portion of the plurality of electromagnetic steel plates 2 constituting the rotor core 1.

Embodiment 3 FIG.
Next, a rotor according to Embodiment 3 of the present invention will be described with reference to FIGS. FIG. 9 is a longitudinal sectional view showing a magnet insertion hole portion of the rotor according to the third embodiment, with the end plate omitted. In addition, the same code | symbol is attached | subjected about the structure same as the rotor demonstrated in

Embodiment

1 and 2, and the description is abbreviate | omitted suitably.

In the rotor according to the third embodiment, as shown in FIG. 9, the pressing portion 8 is formed in a pair of flat plates protruding from the opening edge facing in the circumferential direction of the magnet insertion hole 3 toward the center of the magnet insertion hole 3. It is a configuration. The flat pressing portion 8 can strongly press the permanent magnet 4 downward in the rotation axis direction P using the elastic force of the electromagnetic steel plate 2.

FIG. 10 is a plan view showing a rotor provided with a magnet stopper for positioning the permanent magnet inserted into the magnet insertion hole, with the end plate omitted. FIG. 11 is an enlarged plan view showing the magnet insertion portion shown in FIG. FIG. 12 is an enlarged plan view showing a magnet insertion portion of the rotor which is pressed by flatly pressing the magnet stopper. As shown in FIGS. 10 and 11, the embedded magnet type rotor has a configuration in which a magnet stopper 9 is provided for positioning and fixing the position of the permanent magnet 4 inserted in each magnet insertion hole 3. In this case, the flat pressing portion 8 can be formed by flat-pressing the magnet stopper 9 in advance as shown in FIG.

FIG. 13 is a longitudinal sectional view showing a magnet insertion hole portion in which the end plate is omitted, which is a modification of the rotor according to the third embodiment. As shown in FIG. 13, the flat pressing portion 8 may have a configuration formed on a plurality of (three in the illustrated example) electromagnetic steel plates 2 disposed on the top of the rotor core 1. In this case, the flat pressing portion 8 can strongly press the permanent magnet 4 downward in the rotation axis direction P by its elastic force.

Therefore, the rotor according to the third embodiment is in contact with the end of the permanent magnet 4 inserted into the magnet insertion hole 3 on the electromagnetic steel plate 2 arranged on the upper portion of the rotor core 1 so that the permanent magnet 4 is rotated. Since the flat pressing portion 8 that presses in the direction P is formed, the position of the permanent magnet 4 can be firmly fixed by the pressing portion 8 and noise generated during operation of the rotary electric motor 300 can be reduced. Can do.

Further, the rotor according to the third embodiment is configured by a pair of flat plates in which the pressing portion 8 protrudes from the opening edge facing the magnet insertion hole 3 toward the center of the magnet insertion hole 3. 9 can be formed by flat-pressing, and the pressing portion 8 can be easily molded and the manufacturing cost can be reduced.

Further, the rotor according to the third embodiment has a pair of presses even when the permanent magnet 4 is constituted by two pieces divided in the circumferential direction of the rotor core 1 in order to reduce magnet eddy current loss. Each pressing portion of the portion 8 can press the divided permanent magnets 4 in the rotation axis direction P.

In addition, the flat pressing part 8 is not limited to the structure formed in the electromagnetic steel plate 2 of the 2nd step | paragraph from the top, as shown in FIG. Even if the flat pressing part 8 is formed on the electromagnetic steel sheet 2 (for example, the electromagnetic steel sheet 2 positioned at the uppermost stage or the third stage) disposed at the upper part of the plurality of electromagnetic steel sheets 2 constituting the rotor core 1. Good.

Further, the flat pressing portion 8 is an electromagnetic steel plate 2 disposed in the lower part of the plurality of electromagnetic steel plates 2 constituting the rotor core 1, and is provided at the end of the permanent magnet 4 inserted into the magnet insertion hole 3. A configuration in which the permanent magnet 4 is pressed upward in the rotation axis direction P may be used.

Although the present invention has been described above based on the embodiment, the present invention is not limited to the configuration of the embodiment described above. For example, the pressing portion 6 may be configured to be formed on the opening edge facing in the radial direction of the magnet insertion hole 3. In short, it should be noted that the scope of the present invention also includes the scope of various changes, applications, and uses made by those skilled in the art as needed.

1 rotor core, 2, 2a electromagnetic steel plate, 3 magnet insertion hole, 4 permanent magnet, 5 end plate, 6, 7, 8 pressing part, 9 magnet stopper, 10 shaft insertion hole, 11 slit, 12 air hole part, 13 rivet insertion hole , 60 inclined surface part, 61 flat part, 70 projecting part, 100 rotor, 200 stator, 201 stator core, 202 core back part, 203 teeth part, 300 rotary motor.

Claims

A rotor core having a plurality of magnet insertion holes formed by laminating a plurality of steel plates in the rotation axis direction and penetrating in the rotation axis direction;
A permanent magnet inserted into the magnet insertion hole;
An end plate disposed on an end surface of the rotor core in the rotation axis direction,
The steel plate disposed on one end side or the other end side of the rotor core is in contact with the end of the permanent magnet inserted into the magnet insertion hole and presses the permanent magnet in the direction of the rotation axis. The rotor in which the pressing part is formed.
The pressing portion is
An inclined surface portion inclined toward the permanent magnet from the opposite opening edge of the magnet insertion hole;
A flat surface portion that protrudes from the end of the inclined surface portion toward the center of the magnet insertion hole, contacts the end of the permanent magnet, and presses in the rotation axis direction;
The rotor according to claim 1, wherein the rotor is formed in a pair of spring plate shapes.
2. The rotor according to claim 1, wherein the pressing portion is formed in a pair of flat plates protruding from one opposing opening edge of the magnet insertion hole toward the center of the magnet insertion hole.
The permanent magnet is composed of two divided in the circumferential direction of the rotor core,
The rotor according to claim 2 or 3, wherein the pair of pressing portions is configured to press each permanent magnet into which the pressing portions are divided in the direction of the rotation axis.
The permanent magnet is composed of a plurality of parts divided in the circumferential direction of the rotor core,
The pressing portion is formed in a zigzag shape from one opening edge facing the magnet insertion hole to the other opening edge as seen from the rotation axis direction, and the cross-sectional shape is also formed in a zigzag shape,
2. The rotor according to claim 1, wherein each protrusion of the pressing portion in the rotation axis direction abuts against a corresponding end portion of the permanent magnet and presses the plurality of permanent magnets in the rotation axis direction.
The rotor according to any one of claims 1 to 5, wherein the pressing portion is formed on a plurality of steel plates disposed at an upper portion or a lower portion of the rotor core.
A rotary electric motor comprising the rotor according to any one of claims 1 to 6.