JP2002034182A - Motor rotor and manufacturing method therefor, induction motor, and synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor rotor capable of attaining easy manufacturing, high efficiency, and less noise. SOLUTION: This rotor is formed into an integrated structure by sintering a material in which a highly magnetic metal material and a highly conductive metal material are mixed, so as to have higher metallic composition percentage of high conductivity as it moves closer to an outer-periphery surface. For more appropriate distribution of magnetic reluctance on the rotor, the rotor is formed so as to have various types of grooves, slits, permanent magnets, and inner and outer double-layer structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction motor for a blower requiring relatively low output and low noise, and more particularly to a single-phase induction motor and a shaded induction motor.

[0002]

2. Description of the Related Art In recent years, induction motors for blowers have been required to have high efficiency and low noise for the purpose of energy saving. Induction machines are often operated at variable speeds to obtain the required airflow only when needed.

FIG. 13 is a view showing a rotor and a stator of a conventional cage-type induction motor. In FIG. 13, reference numeral 1 denotes a stator core formed by laminating a large number, 2 denotes a stator slot, and 3 denotes a stator tooth. Reference numeral 4 denotes a rotor core formed by laminating a large number, 5 denotes a slot of the rotor, and 6 denotes teeth of the rotor.

[0004] Twenty-four stator slots 2 are arranged at equal intervals on the inner periphery of the stator core 1. Inside the slots 2 of the stator, for example, two-pole, two-phase windings (coils) are inserted. By applying a single-phase voltage to one of the coils and applying a voltage to the other coil by, for example, connecting a capacitor in series, a rotating magnetic field having the applied AC power frequency is applied to the rotor.

The slots 5 of the rotor are arranged at equal intervals on the outer periphery of the rotor core 4, and a bar of a secondary conductor is formed inside. FIG. 14 is a view showing the appearance, and 11 is an end ring, which electrically connects the secondary conductor bars.

FIG. 15 is a cross-sectional view of the vicinity of the slot portion of the rotor. The slots 5 of the rotor may be skewed obliquely for low vibration, low noise, and stabilization of the rotation drive. The secondary conductor bar 10 is provided inside the slot 5 of the skewed rotor. It is formed.

[0007] Due to the rotating magnetic field given by the stator, a current flows through the secondary conductor bar 10 of the rotor to cancel it. The rotor is driven to rotate based on the operation principle of a so-called cage induction motor.

[0008]

Since the conventional squirrel-cage induction motor is constructed as described above, in the combination of the stator and the rotor as described above, harmonics caused by slots provided in each of the stators and the rotors are generated. Pulsating torque is generated,
In some cases, the driving of the motor becomes unstable or the sound becomes an electromagnetic sound and the noise is increased. In particular, when the power applied to the rotor coil is an AC power having a distortion generated by an inverter or phase control, the pulsating torque and the electromagnetic noise are further increased.

As a countermeasure, pulsating torque can be reduced by skewing the slots of the rotor in the laminating direction. However, manufacturing is difficult, efficiency is reduced,
This may cause an axial excitation force.

The present invention has been made to solve the above problems, and has as its object to facilitate manufacture of a rotor, reduce pulsating torque generated by distortion of a rotating magnetic field, and reduce noise of an electric motor. And

[0011]

The rotor of the electric motor according to the present invention is integrally formed by sintering a material obtained by mixing a highly magnetic metal material and a highly conductive metal material. The conductive metal composition ratio is increased.

Further, an iron-copper-based sintered material is used, and the composition ratio of copper is increased nearer the outer peripheral surface.

Further, a gap is formed inside the rotor as many as the number of poles so that the magnetic resistance greatly changes in the circumferential direction.

Further, the air gap formed inside the rotor is formed in an inverted arc shape.

Further, a permanent magnet is inserted into a gap formed inside the rotor.

Further, a circumferential groove is provided on the outer peripheral surface.

Further, an axial groove is provided on the outer peripheral surface.

Further, the axial grooves have a pitch smaller than the slot opening width of the stator.

An induction motor according to the present invention uses the rotor of the motor according to the first aspect.

Further, the variable speed drive is performed by phase control.

Further, the structure of the stator is a hollow type.

Further, the stator is a concentrated winding type.

A synchronous electric motor according to the present invention uses the rotor of the electric motor according to the fourth aspect.

Further, a motor rotor according to claim 5 is used.

In the induction motor according to the present invention, the axial length of the rotor is longer than that of the stator.

In the synchronous motor according to the present invention, the length of the rotor in the axial direction is longer than that of the stator.

[0027] The induction motor according to the present invention is characterized in that:
8. A motor using the rotor of the electric motor described in any one of 8.

The synchronous motor according to the present invention is described in claim 6.
A rotor using the rotor of the electric motor according to any one of claims 1 to 8.

A method for manufacturing a rotor for an electric motor according to the present invention is the method for manufacturing a rotor for an electric motor according to claim 1, wherein the upper mold is in the lower mold and the surface of the rotor is The portion of the layer having a high ratio of the highly conductive metal material is closely adhered to the lower mold as a first gap, and the ratio of the highly conductive metal material, which is a sintered material, to the highly magnetic metal material is high in the first gap. A step of introducing a first sintering material powder largely mixed with the conductive metal, and a step of forming a first ring-shaped piston fitted into the first gap by compressing and solidifying the first sintering material powder. And the upper mold is removed, and a cylinder having an outer diameter smaller than that of the upper mold is placed in close contact with the lower mold, and a second gap between the cylinder and the ring-shaped solid is formed. Supplying a second sintered material powder having a high ratio of a high magnetic metal material, and a second phosphor fitted into the second gap. A step of compressing and solidifying the second sintered material powder with a ring-shaped solid having a high ratio of a high-conductivity metallic material, and bringing the integrated compressed solid to a predetermined temperature in a high-temperature furnace. And sintering.

The rotor of the electric motor according to the present invention has a first material layer mixed with a high magnetic metal material having a high ratio of a high conductive metal material in a ring shape on the rotor surface side.

Further, inside the ring-shaped first material layer,
The second material layer made of iron ingot is arranged.

Further, inside the ring-shaped first material layer,
A second material layer composed of a laminated steel sheet is disposed.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1 to 4 show a first embodiment, FIG. 1 is a perspective view showing a rotor of an induction motor, FIGS. 2 and 3 are sectional views showing a rotor material composition distribution of the induction motor, and FIG. 4 is an induction motor. FIG. 5 is a view showing a mold structure for manufacturing the rotor of FIG. The rotor material is composed of a highly magnetic metal material having a high magnetic permeability and a highly conductive metal material having a high conductivity, and is integrated by a sintering method. In addition, the metal material having higher conductivity is made to have a higher composition distribution as the surface is closer to the rotor.

As the sintering material, for example, an iron-copper-based sintering material is used to integrally form the rotor, and the sintering material on the rotor surface side is made to have a high copper composition ratio. .

In FIG. 2, a first material layer 23 mixed with a high magnetic metal material having an increased ratio of a highly conductive metal material is arranged in a ring shape on the rotor surface side, and a high material layer 23 is provided inside the ring layer. A second material layer 24 having a higher magnetic metal material ratio is disposed.

FIG. 3 shows another distribution pattern. In the embodiment shown here, the material ratio is distributed in two layers, but the distribution can be changed by changing the material ratio in any number of layers according to a manufacturing method described later.

Next, the operation will be described. The rotor 21 shown in FIG. 1 is used, for example, as the rotor of the induction motor shown in FIG. Twenty-four stator slots 2 are arranged at equal intervals on the inner periphery of the stator core 1, and for example, a two-pole, two-phase winding (coil) is inserted inside the stator slot 2. When a single-phase voltage is applied to one of the coils and a capacitor is connected in series to the other coil, for example, and a voltage is applied, a rotating magnetic field of the applied AC power supply frequency is applied to the rotor 21.

Due to the rotating magnetic field given by the stator, a current flows through the highly conductive metal material portion of the rotor to cancel it (secondary current). The rotor is driven to rotate based on the operation principle of a so-called cage induction motor.

On the other hand, since there is no slot in the rotor, the distortion of the rotating magnetic field generated by the combination of the slot of the stator and the rotor slot does not occur, so that the torque induced by the distortion of the rotating magnetic field is reduced and noise is reduced. , Stable driving can be realized.

According to the principle of the induction motor, the torque speed characteristic of the motor can be greatly changed by the resistance of the secondary conductor of the rotor. In the present invention, however, the highly conductive metal of the material disposed on the rotor surface side is also used. By adjusting the material ratio,
The secondary resistance value can be changed, and the torque characteristics can be adjusted.

The manufacturing method will be described with reference to FIG.
In FIG. 4A, reference numeral 25 denotes a lower mold. Reference numeral 26 denotes an upper mold, and a portion of a layer (ring portion) in the lower mold 25 where the ratio of the highly conductive metal material is large on the surface of the rotor is used as a first gap 27 so as to adhere to the lower mold 25. I have. First gap 27
A first sintered material powder 28 in which the ratio of a highly conductive metal material and a highly magnetic metal material as a sintering material is greatly mixed with a highly conductive metal is supplied. The first fit into the first gap 27
The ring-shaped piston 29 compresses and solidifies the first sintered material powder 28 to form a ring-shaped solid 30.

Next, FIG. 4B shows a state in which the upper mold 26 is removed, and a column 31 having a smaller outer diameter than the upper mold 26 is placed in close contact with the lower mold 25. I have. A second sintered material powder 34 having a high ratio of a high magnetic metal material is introduced into a second gap 33 between the column 31 and the ring-shaped solid 30, and a second fit into the second gap 33. The ring-shaped piston 32 compresses and solidifies the second sintered material powder 34 to be integrated with the ring-shaped solid 30 having a high high conductivity metal material ratio. The integrated compressed solid is sintered at a predetermined temperature in a high-temperature furnace.

In the above embodiment, the second material layer 24 on the inner diameter side of the rotor is formed of the second sintered material powder 34. However, the material of the second material layer 24 is pure. It may be an iron lump or a laminated steel sheet.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. 5 and 6 show a second embodiment. FIG. 5 shows a second embodiment using the rotor of the first embodiment.
Circuit configuration diagram for controlling the phase of the phase induction motor and driving it at a variable speed,
FIG. 6 is a diagram showing the state of current flowing through the induction motor winding when the two-phase induction motor is phase-controlled and driven at a variable speed.

In FIG. 5, reference numeral 21 denotes a rotor of the first embodiment; 41, a first phase winding (main winding) wound around a stator;
2 is a second phase winding (auxiliary winding), 43 is a phase advance capacitor,
44 is a triac, 45 is a gate of the triac 44, and 46 is a commercial power supply (50/60 Hz). The first phase winding 41, the second phase winding 42, the phase advance capacitor 43, and the rotor 21 constitute an induction motor.

As shown in FIG. 6, the application of the applied voltage (a), which is the commercial power supply voltage, to the induction motor is controlled by a triac gate drive signal (b), and the gate drive signal (b) is at a high level in the figure. At this time, a voltage is applied to the induction motor, and a drive current flows as shown in FIG. This drive current contains many harmonics.

In the phase control, the first phase winding 4
In order to create a rotating magnetic field for driving the rotor in the windings of the first and second phase windings 42, the rotating magnetic field also includes harmonic components as well as current. However, by using the rotor 21 of the first embodiment, the distortion of the rotating magnetic field generated between the rotor and the stator shown in the conventional example is reduced, so that more harmonic components are not increased. As a result, the noise level is low.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a view showing the third embodiment, and is a cross-sectional view showing the structure of a shaded motor using the rotor of the first embodiment. In the figure, 50 is a laminated iron core (core), 61 is a winding wound on the laminated iron core 50 (primary excitation coil), 51 is a shading coil, and 21 is a rotor of the first embodiment.

In the shaded motor, an AC voltage is applied to the winding 61, and the current flows, so that the wound iron core has four magnetic poles (in FIG. 7, the winding 61 is wound around four iron cores). creating. Since the shading coil 51 is wound around a part of the generated magnetic pole, the magnetic flux is delayed, and a moving magnetic field (rotating magnetic field) is generated, so that the rotor is rotationally driven by the rotating magnetic field. However, due to the driving principle, the rotating magnetic field generated by the winding 61 and the shading coil 51 has a large distortion and often causes a pulsation in the driving torque.

However, by using the rotor of the first embodiment, the distortion of the rotating magnetic field generated between the rotor and the stator shown in the prior art is reduced, so that more harmonic components are increased. No noise, resulting in low noise.

Embodiment 4 FIG. Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 8 shows the fourth embodiment and is a cross-sectional view showing the structure of a concentrated winding induction motor using the rotor of the first embodiment. In the figure, 5
2 is a first phase winding (main winding) intensively wound around salient poles made of a laminated iron core 52, and 42 is intensively wound around other salient poles. 2nd phase winding (auxiliary winding), 2
Reference numeral 1 denotes a two-pole, two-phase, induction motor, which is the rotor according to the first embodiment. The first phase winding 41 and the second phase winding 42 are connected as shown in the drive circuit diagram of FIG.
By changing the phase of the current flowing through the phase winding 41 and the second phase winding 42 to generate a rotating magnetic field, the rotor 21 is rotationally driven.

For example, in a concentrated winding type iron core structure as shown in FIG. 8, the magnetic poles formed in each phase have a rotor electric angle of 90 °.
Therefore, the rotating magnetic field generated by the two-phase windings is greatly distorted, causing pulsation in the driving torque.

When two-phase windings are applied to the stator shown in FIG. 13 shown in the prior art, the magnetic poles formed in each phase are 180 degrees in electrical angle of the rotor, and the rotating magnetic field formed by the two-phase windings is concentrated. Less distortion than wire wound type.

However, by using the rotor of the first embodiment, the distortion of the rotating magnetic field generated between the rotor and the stator shown in the prior art is reduced, so that more harmonic components are increased. No noise, resulting in low noise.

Embodiment 5 Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 9 shows the fifth embodiment, and is a cross sectional view showing the structure of the rotor. As described in the first embodiment, the entire rotor is made of a high magnetic metal material having a high magnetic permeability and a high conductive metal material having a high conductivity, and the materials are integrated by a sintering method.

Further, the composition ratio is so set that the closer to the surface of the rotor, the higher the conductivity of the metal material and the higher the composition distribution. In the rotor, three sets of inverted arc-shaped voids 55 are uniformly arranged in three layers, so that the magnetic resistance greatly changes in the circumferential direction. As a result, the inductance value Ld in the d-axis direction 56 of FIG.
7, there is a large difference between the inductance values Lq and Lq>
Ld.

The rotor having such characteristics can be driven to rotate by generating reluctance torque in synchronization with the rotating magnetic field generated by the stator. In addition, since the surface side of this rotor has the characteristics of the rotor of an induction motor, when the motor is started, it is started by the rotating magnetic field created by the stator like an induction motor, and finally synchronized by the internal structure of the rotor. Driving is possible.

As a result, a current called a secondary current flows through the rotor during operation as an induction motor, but the current does not flow during synchronous operation, so that loss is reduced and efficiency is improved.

Embodiment 6 FIG. Hereinafter, a sixth embodiment of the present invention will be described with reference to the drawings. FIG. 10 shows a sixth embodiment.
FIG. 4 is a cross-sectional view showing a structure of a rotor. FIG.
The permanent magnet 62 is inserted into the space 55 inside the rotor described in the above section, and four permanent magnets 62 are used to form the poles. As described in the fifth embodiment, this rotor starts at the time of startup due to the characteristics of the rotor of the induction motor on the rotor surface, and finally can perform synchronous operation due to the internal structure of the rotor.

During synchronous operation, the built-in permanent magnet 6
2 further generates a suction repulsive force with the rotating magnetic field generated by the stator, so that the amount of the rotating magnetic field on the stator side required for generating the rotating torque can be reduced, so that the efficiency is improved.

Embodiment 7 FIG. Hereinafter, a seventh embodiment of the present invention will be described. In the present embodiment, the configuration is such that the axial length of the rotor is greater than the axial length of the stator. This allows a large amount of current flowing on the rotor side due to the rotating magnetic field generated by the stator to flow to portions where the rotor and the stator are not facing, reducing loss in the secondary current, and reducing magnetic loss as viewed from the stator side. Since the resistance is reduced, the amount of current (ampere turn) for generating a rotating magnetic field can be reduced, so that efficiency is improved. The type of motor can be applied to both induction motors and synchronous motors.

Embodiment 8 FIG. Hereinafter, an eighth embodiment of the present invention will be described with reference to the drawings. FIG. 11 shows an eighth embodiment.
FIG. 4 is a perspective view of a rotor. As shown in the figure,
A plurality of narrow circumferential grooves are provided on the surface of the rotor. The rotor surface is made of a highly conductive material and is integrally formed by sintering, so the magnetic field created by the stator near the stator surface passes only through the rotor surface and returns to the stator side to rotate. In some cases, eddy currents are induced in the element to lower the efficiency, but by providing a plurality of thin grooves on the surface, the amount of eddy currents generated can be reduced, resulting in higher efficiency.

Embodiment 9 FIG. Hereinafter, a ninth embodiment of the present invention will be described with reference to the drawings. FIG. 12 shows Embodiment 9
FIG. 4 is a perspective view of a rotor. As shown in the figure,
A plurality of thin axial grooves are provided on the surface of the rotor horizontally in the axial direction. Since the rotor surface is made of a highly conductive material and is integrally formed by sintering, the magnetic field created by the stator passes only through the rotor surface and returns to the stator side near the stator surface. In some cases, only the eddy current is induced in the element to reduce the efficiency. However, by providing a plurality of axially thin grooves in the axial direction on the surface, the amount of eddy current generated can be reduced, so that the efficiency is improved.

The phenomenon that the magnetic field generated by the stator near the surface of the stator passes only through the surface of the rotor and returns to the stator side to induce only eddy current in the rotor is caused by the vicinity of the slot opening of the stator. Therefore, by providing the grooves at a pitch smaller than the slot opening width of the stator, the eddy current on the rotor surface can be effectively reduced and the efficiency can be improved.

[0065]

The rotor of the electric motor according to the present invention is integrally formed by sintering a material obtained by mixing a highly magnetic metal material and a highly conductive metal material. By increasing the ratio, manufacture of the rotor is facilitated, and pulsating torque generated by distortion of the rotating magnetic field when used in the motor can be reduced to reduce noise of the motor.

Further, an iron-copper-based sintered material is used, and the composition ratio of copper is increased toward the outer peripheral surface. This facilitates manufacture of the rotor, reduces pulsating torque generated by distortion of the rotating magnetic field when used in the motor, and reduces noise of the motor.

Further, since the air gap is formed inside the rotor as much as the number of poles so that the magnetic resistance largely changes in the circumferential direction, the efficiency can be increased when used in a synchronous motor.

Further, since the gap formed inside the rotor is formed in an inverted arc shape, the magnetic resistance can be largely changed in the circumferential direction.

Also, since the permanent magnet is inserted into the gap formed inside the rotor, when used in a synchronous motor, the amount of the rotating magnetic field on the stator side required to generate the rotating torque is reduced. Efficiency can be improved.

Further, since the circumferential groove is provided on the outer peripheral surface, the amount of eddy current generated can be reduced, so that the efficiency is improved.

Further, since the axial groove is provided on the outer peripheral surface, the amount of eddy current generated can be reduced, so that the efficiency is improved.

Further, since the pitch of the axial grooves is smaller than the slot opening width of the stator, the eddy current on the rotor surface can be effectively reduced and the efficiency can be improved.

The induction motor according to the present invention uses the rotor of the motor according to the first aspect, thereby facilitating manufacture, reducing pulsation torque generated by distortion of the rotating magnetic field, and reducing the noise of the induction motor. Can be planned.

Further, even when the motor is driven at a variable speed by the phase control, the use of the rotor of the electric motor according to the first aspect reduces the distortion of the rotating magnetic field generated between the rotor and the stator. Noise can be reduced without increasing the harmonic components of.

Further, even when the structure of the stator is a hollow type, the use of the rotor of the electric motor according to the first aspect reduces the distortion of the rotating magnetic field generated between the rotor and the stator. Therefore, the noise can be reduced without increasing more harmonic components.

Further, even when the stator is a concentrated winding type,
By using the rotor of the electric motor according to claim 1, the distortion of the rotating magnetic field generated between the rotor and the stator is reduced, so that more harmonic components are not increased,
Low noise can be achieved.

In the synchronous electric motor according to the present invention, since the secondary current does not flow during the synchronous operation by using the rotor of the electric motor according to the fourth aspect, the loss is reduced and the efficiency is improved.

Further, by using the rotor of the electric motor according to the fifth aspect, at the time of synchronous operation, a suction repulsive force is further generated between the built-in permanent magnet and the rotating magnetic field generated by the stator, so that a rotating torque is generated. Therefore, the amount of the rotating magnetic field on the side of the stator required for the operation can be reduced, so that the efficiency is improved.

In the induction motor according to the present invention, since the length of the rotor in the axial direction is made longer than that of the stator, the magnetic low resistance seen from the stator side is reduced, so that the amount of current for generating the rotating magnetic field can be reduced, so that the efficiency is improved Will be better.

In the synchronous motor according to the present invention, since the length of the rotor in the axial direction is made longer than that of the stator, the magnetic low resistance as viewed from the stator side is reduced, so that the amount of current for generating a rotating magnetic field can be reduced. Efficiency is improved.

According to the method for manufacturing a rotor of a motor according to the present invention, the upper mold is in the lower mold and the portion of the layer having a high ratio of the highly conductive metal material on the surface of the rotor is defined as the first gap. A step in which a first sintered material powder in which a ratio of a highly conductive metal material and a highly magnetic metal material as a sintering material is largely blended into a highly conductive metal is put into a first gap in a first gap. A step in which a first ring-shaped piston fitted into the first gap compresses and solidifies the first sintered material powder to form a ring-shaped solid; and the upper mold is removed, and A cylinder having an outer diameter smaller than that of the mold is placed in close contact with the lower mold, and a second sintered material powder having a high ratio of a high magnetic metal material is introduced into a second gap between the cylinder and the ring-shaped solid. And the second ring-shaped piston fitted into the second gap compresses and hardens the second sintered material powder to provide high conductivity. And a step of sintering the integrated compressed solid at a predetermined temperature in a high-temperature furnace, thereby manufacturing a rotor. Easy.

Since the rotor of the electric motor according to the present invention has a first material layer mixed with a high magnetic metal material having a high ratio of a high conductive metal material in a ring shape on the rotor surface side,
The pulsation torque generated by the distortion of the rotating magnetic field when used in an electric motor can be reduced to reduce the noise of the electric motor.

[Brief description of the drawings]

FIG. 1 is a view showing Embodiment 1, and is a perspective view showing a rotor of an induction motor.

FIG. 2 is a diagram illustrating the first embodiment and is a diagram illustrating a rotor material composition distribution of the induction motor.

FIG. 3 is a diagram showing the first embodiment and is a diagram showing a rotor material composition distribution of the induction motor.

FIG. 4 is a view showing the first embodiment and is a view showing a mold structure for manufacturing a rotor of the induction motor.

FIG. 5 is a diagram showing the second embodiment, and is a diagram showing a circuit configuration for controlling the phase of a two-phase induction motor and driving it at a variable speed.

FIG. 6 is a diagram showing the second embodiment, and is a diagram showing a state of a current flowing through an induction motor winding when a two-phase induction motor is phase-controlled and driven at a variable speed.

FIG. 7 is a view showing the third embodiment, and is a cross-sectional view showing the structure of a shaded motor using the rotor of the first embodiment.

FIG. 8 shows the fourth embodiment, and is a cross-sectional view showing the structure of a concentrated winding induction motor using the rotor of the first embodiment.

FIG. 9 shows the fifth embodiment, and is a cross-sectional view showing the structure of the rotor.

FIG. 10 shows the sixth embodiment, and is a cross-sectional view showing the structure of the rotor.

FIG. 11 shows the eighth embodiment and is a perspective view showing a rotor.

FIG. 12 shows the ninth embodiment, and is a perspective view showing a rotor.

FIG. 13 is a diagram showing a rotor and a stator of a conventional cage-type induction motor.

FIG. 14 is an external view of a rotor of a conventional cage-type induction motor.

FIG. 15 is a cross-sectional view of the vicinity of a slot of a rotor of a conventional cage induction motor.

[Explanation of symbols]

21 rotor, 23 first material layer, 24 second material layer, 25 lower mold, 26 upper mold, 27 first gap,
28 first sintered material powder, 29 first ring-shaped piston, 30 ring-shaped solid, 31 cylinder, 32 second ring-shaped piston, 33 second void, 34 second sintered material powder, 41 First phase winding, 42 Second phase winding, 43
Phase-advancing capacitor, 44 triac, 45 triac gate, 46 commercial power supply, 50 laminated core, 5
1 Shading coil, 52 laminated iron core, 55 gap, 5
6 d-axis direction, 57 q-axis direction, 58 circumferential groove, 5
9 axial grooves, 61 windings, 62 permanent magnets.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 17/16 H02K 17/16 B 19/10 19/10 A 19/14 19/14 Z (72) Invention Person Kazuhiko Baba 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Atsushi Matsuoka 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Yoshino Hayato 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Takahiro Tsutsumi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation 5H002 AA03 AA04 AA07 AA09 AB07 AB08 AE06 5H013 NN10 PP06 5H615 AA01 BB01 BB06 BB07 BB14 BB16 PP02 PP06 SS05 SS12 SS13 SS19 TT01 TT04 5H619 AA01 AA03 AA07 BB06 BB15 BB22 BB24 PP02 CA04 PP08 5H622 A13 03

Claims (22)

[Claims] An electric motor characterized in that a material obtained by mixing a highly magnetic metal material and a highly conductive metal material is sintered and integrally formed, and the composition ratio of the highly conductive metal increases as it approaches the outer peripheral surface. Rotor. 2. The motor rotor according to claim 1, wherein an iron-copper-based sintered material is used, and the composition ratio of copper is increased toward the outer peripheral surface. 3. The rotor for an electric motor according to claim 1, wherein air gaps are formed inside the rotor as many as the number of poles so that the magnetic resistance changes greatly in the circumferential direction. 4. The rotor for an electric motor according to claim 3, wherein a gap formed inside the rotor is formed in an inverted arc shape. 5. The rotor for an electric motor according to claim 3, wherein a permanent magnet is inserted into a gap formed inside the rotor. 6. The rotor for an electric motor according to claim 1, wherein a circumferential groove is provided on an outer peripheral surface. 7. The rotor for an electric motor according to claim 1, wherein an axial groove is provided on an outer peripheral surface. 8. The rotor for an electric motor according to claim 7, wherein the axial grooves have a pitch smaller than a slot opening width of the stator. 9. An induction motor using the rotor of the electric motor according to claim 1. 10. The induction motor according to claim 9, wherein the motor is driven at a variable speed by phase control. 11. The induction motor according to claim 9, wherein the stator has a hollow structure. 12. The induction motor according to claim 9, wherein the stator is a concentrated winding type. 13. A synchronous motor using the rotor of the motor according to claim 4. 14. A synchronous motor using the rotor of the motor according to claim 5. 15. The induction motor according to claim 9, wherein an axial length of the rotor is longer than that of the stator. 16. The synchronous motor according to claim 13, wherein an axial length of the rotor is longer than that of the stator. 17. An induction motor using the rotor of the electric motor according to claim 6. Description: 18. A synchronous motor using the motor rotor according to claim 6. Description: 19. The method for manufacturing a rotor for an electric motor according to claim 1, wherein the upper die is in the lower die, and the portion of the layer having a high ratio of the highly conductive metal material on the surface of the rotor. The first
A first sintered material powder in which a ratio of a highly conductive metal material and a high magnetic metal material, which is a sintering material, is largely blended with a highly conductive metal in the first void as a void. And a step in which the first ring-shaped piston fitted into the first gap compresses and solidifies the first sintered material powder to form a ring-shaped solid. A cylinder having a smaller outer diameter than the upper mold is placed in close contact with the lower mold, and a second gap having a high magnetic metal material ratio is provided in the second gap between the cylinder and the ring-shaped solid. And the second ring-shaped piston fitted into the second gap compresses and solidifies the second sintered material powder, so that the high conductivity metal material ratio is high. A step of integrating with the ring-shaped solid; and bringing the integrated compressed solid to a predetermined temperature in a high-temperature furnace. And a step of sintering the rotor. 20. A first magnetic material mixed with a high magnetic metal material having an increased ratio of a high conductive metal material in a ring shape on the rotor surface side.
A rotor for an electric motor, comprising: 21. The motor rotor according to claim 20, wherein a second material layer made of an iron lump is arranged inside the ring-shaped first material layer. 22. The motor rotor according to claim 20, wherein a second material layer made of a laminated steel sheet is disposed inside the ring-shaped first material layer.