JP2001086672A - Permanent magnet rotating machine, and electric vehicle using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge the main density, and besides, to reduce the noise, in a permanent magnet rotating machine where permanent magnets are arranged in circular form inside the iron core of a rotor. SOLUTION: This is a permanent magnet rotating motor which has a rotor 3 having permanent magnets 6 arranged in circular form within a rotor iron core 7 and a stator 2 having stator winding 5 wound on a salient pole 42 constituted of one part of a stator iron core 4, and in which the air gap between the rotor iron core 7 between the poles of the permanent magnet 6 and the stator iron core 4 is larger than the air gap between the rotor iron core 7 at the center of the pole of the permanent magnet 6 and the stator iron core 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a permanent magnet rotating electric machine,
And an electric vehicle using the same.

[0002]

2. Description of the Related Art As a conventional permanent magnet rotating electric machine, an internal magnet type electric machine in which a permanent magnet is inserted into a silicon steel plate is disclosed in Japanese Patent Application Laid-Open No. HEI 9-163568.
No. 9-247880.

In this configuration, since the rotor has a cylindrical shape, the gap between the rotor core and the stator salient poles is constant on the rotor surface. Further, the thickness of the permanent magnet in the radial direction is constant at any part in the rotation direction.

[0004]

In the configuration described in the above publication, when a current is applied to the stator winding and an armature reaction is applied between the permanent magnet poles, the magnetic flux is generated not only in the permanent magnet but also in the permanent magnet. Acts on the iron core existing on the stator side of the iron and the iron core between the adjacent permanent magnets.

[0005] The magnetic flux acts on the core portion existing on the stator side of the permanent magnet and the core portion between the adjacent permanent magnets, thereby increasing the inductance of the stator winding.

As a result, the magnetic flux generated by the stator is not acted on efficiently, so that an extra amount of current is required to obtain the same output torque, which is inefficient.

Further, an increase in the magnetic flux from the stator winding due to an increase in the amount of energization is a main cause of noise generation.

SUMMARY OF THE INVENTION It is an object of the present invention to make the magnetic flux generated by the stator act efficiently, improve the power utilization rate, and avoid the generation of noise due to an unnecessary increase in the magnetic flux.

[0009] Further, an electric vehicle with a long running distance at the same energy can be provided by efficiently utilizing the stored electric energy by efficiently applying a magnetic flux generated by a stator to improve a current utilization rate. As an issue.

[0010]

SUMMARY OF THE INVENTION The present invention comprises a rotor having permanent magnets annularly arranged in an iron core, and a stator winding wound on salient poles formed by a part of the iron core. A permanent magnet rotating electric machine having a stator, wherein a gap between the rotor core and the stator core in a gap between the permanent magnets is defined by a gap between the rotor core and the stator core in a pole center of the permanent magnet. This is a permanent magnet rotating electric machine that is larger than the air gap with the stator core.

Further, the present invention provides a rotor having a permanent magnet annularly arranged in an iron core, and a stator having a stator winding wound around a salient pole constituted by a part of the iron core. A permanent magnet rotating electric machine, wherein the thickness of the permanent magnet in the radial direction of the rotor is largest at a pole center portion, and gradually becomes thinner toward a gap between the poles.

The present invention also provides a rotor having permanent magnets annularly disposed in an iron core made of laminated steel plates, and a stator winding wound around salient poles made up of a part of the iron core. A permanent magnet rotating electric machine having the rotor core, wherein the rotor core is a steel plate in which a pole piece located on the stator side of the permanent magnet is intermittently missing, The permanent magnet rotating electric machine is laminated so that at least one magnetic pole piece of the steel plate exists on the stator side of the permanent magnet.

Preferably, in the above, the rotor core is provided with a slit toward the pole center of the adjacent permanent magnets inside the permanent magnet.

According to the above configuration, the magnetic flux from the stator acts more on the center of the pole than on the gap between the poles, and the magnetic flux is effectively used.

The present invention is also an electric vehicle having the above-described permanent magnet rotating electric machine.

According to the above configuration, the magnetic flux generated by the stator in the permanent magnet rotating electric machine used as the driving mechanism is efficiently actuated, and an electric vehicle having a long running distance with the same energy is provided.

[0017]

FIG. 1 is a sectional view of a permanent magnet rotating electric machine according to an embodiment of the present invention in a rotating direction.

FIG. 2 shows an axial sectional view of the permanent magnet rotating electric machine shown in FIG.

This permanent magnet rotating electric machine is an embodiment using a four-pole permanent magnet and a distributed winding winding structure as a stator.

In the figure, a rotating electric machine 1 includes a stator 2 and
It includes the rotor 3, the end bracket 9, and the housing 12.

The stator 2 includes a stator core 4 and a stator winding 5 made of a magnetic material laminated in the axial direction with, for example, a silicon steel plate. Here, the stator core 4 includes an annular stator yoke portion 41 and a stator salient pole 42. The stator windings 5 are wound between the stator salient poles 42 as shown in the figure.

On the other hand, the rotor 3 includes, for example, a permanent magnet 6 and
The rotor includes a rotor core 7 and a shaft 8 made of a magnetic material laminated in the axial direction with a silicon steel plate. The rotor core 7 has a hole for accommodating the permanent magnet 6, a gap-side bridge 71 for holding the permanent magnet 6, and a bridge between permanent magnets positioned between the permanent magnets 6 and serving to hold the gap-side bridge 71. 72 and a yoke portion 78 through which the magnetic flux of the permanent magnet passes.

Here, the permanent magnet rotating electric machine 1 has the following features.

First, the outer periphery of the gap-side bridge 71 holding the permanent magnet 6 is punched with a radius smaller than the inner diameter of the stator core 4. With this configuration, the gap length between the inner periphery of the stator core 4 and the outer periphery of the gap-side bridge 71 is small at the pole center of the permanent magnet rotor 2 and is large between the poles.

The second feature is that the center position of the circular arc is specified on the gap side and the counter gap side of the insertion opening of the permanent magnet 6 as shown in the figure. This allows the permanent magnet rotor 2
The thickness of the permanent magnet 6 is small at the center of the pole, and the thickness of the permanent magnet 6 is large between the poles.

Third, as a structure on the side opposite to the gap of the permanent magnet insertion opening of the rotor core 7, a salient pole core 73 forming a magnetic path at the center of the permanent magnet 6 as shown in FIG. As shown in the figure, a slit 75 which is a punched portion formed on the arc and is located between the slits 75 and forms a magnetic path of the permanent magnet 6 and a yoke bridge 74 connecting the slit magnetic path 76 are shown in the figure. Characterized in that they are arranged in

The inside of the slit 75 is generally hollow, and is filled with air which is a non-magnetic material. Further, the inside of the slit 75 may be filled with a non-magnetic material such as varnish or synthetic resin, a non-magnetic conductive material such as aluminum, or the like.

With the above configuration, the magnetic resistance between the poles of the permanent magnet 6 at which the winding magnetomotive force of the stator winding 5 is maximized increases, and the magnetic flux due to the stator winding magnetomotive force can be suppressed.

Generally, the permanent magnet rotating electric machine 1 has a permanent magnet 6
There is a surface magnet type in which the magnet is placed on the surface of the rotor and an internal magnet type in which the magnet is arranged in the rotor core shown in FIG. In the surface magnet method, the magnetic flux generated by the stator winding has a small value because the magnetic permeability of the permanent magnet is as small as 1 and equal to that of air.
The inductance of the stator winding 5 can be reduced, so that a large output can be obtained. Suppression of the magnetic flux generated by the stator winding is also effective in reducing noise and the like. On the other hand, it is difficult to mechanically hold the permanent magnet, and if it is simply held by a stainless steel cylindrical ring, eddy currents will cause a decrease in efficiency, and since stainless steel is non-magnetic, its magnetic length will increase by its thickness. Therefore, there is a problem in that the effective magnetic flux decreases and the torque decreases.

On the other hand, in the internal magnet system, the permanent magnet can be easily held, the reluctance torque can be used because the rotor has saliency, and the gap length can be reduced in structure, thereby improving the torque. And the like. On the other hand, there is a drawback in that a large magnetic flux is generated due to a reduction in the magnetoresistance of the magnetomotive force generated by the stator winding, and the maximum torque is reduced.

The present invention provides an internal magnet system capable of achieving the advantages of the surface magnet system, such as low noise and high output, without impairing the advantages of the internal magnet system.

FIG. 3 shows the principle of operation of the permanent magnet rotating electric machine shown in FIG.

(A) is a circumferential development of the rotor of the present invention, and (b) is an air gap magnetic flux density due to the stator winding magnetomotive force of the present invention. (C) shows the circumferential development of the conventional rotor, and (d) shows the air gap magnetic flux density due to the conventional stator winding magnetomotive force.

The broken line shows the distribution of the stator winding magnetomotive force. It has the largest magnetomotive force between the poles and the smallest value at the pole center.
According to the present invention, firstly, the magnetic path of the gap between the poles is long,
The second point is that the magnetic resistance between the poles is increased, the second is that the magnetic resistance between the poles is increased by increasing the thickness of the permanent magnet between the poles, and the third is that the slit provided in the rotor core 7 is provided. 75 does not greatly affect the magnetic path of the permanent magnet 6, but is divided by the magnetic path slit 75 of the stator winding 5 to increase the magnetic resistance between the poles, and the air gap flux due to the stator winding magnetomotive force Density can be reduced. The decrease in the magnetic flux density due to the stator winding 5 means that the inductance of the stator winding 5 can be reduced, so that the output can be improved. Also, noise is generated by the magnetic flux density generated by the stator winding. Therefore,
This shows that the structure of the present invention that can reduce this can reduce noise.

FIG. 3C shows a circumferential development of the conventional rotor, and FIG. 3D shows the air gap magnetic flux density due to the conventional stator winding magnetomotive force. In the conventional structure, firstly, the magnetic path of the gap between the poles is shortened, and the magnetic resistance between the poles is reduced. Third, since the magnetic path of the stator winding is small in the rotor core 7 because there is no slit, the air gap magnetic flux density due to the stator winding magnetomotive force increases. As a result, a decrease in output, an increase in noise, and an increase in iron loss are inevitable.

FIG. 4 is a sectional view of a permanent magnet rotating electric machine according to another embodiment of the present invention in a rotating direction.

Here, only the rotor part which is an improvement on FIG. 1 is shown. (A) shows the rotor assembly structure,
(B) and (c) show one laminated rotor core.

In the figure, the same reference numerals as those in FIG. 1 indicate the same structures. Here, an example of an 8-pole permanent magnet rotor is shown.

In FIG. 4A, the rotor core 7 is located between the hole for accommodating the permanent magnet 6, the gap-side bridge 71 for holding the permanent magnet 6, and the permanent magnet 6, and the gap-side bridge 7
A bridge 72 between permanent magnets having a role of holding 1;
And a yoke portion 78 through which the magnetic flux of the permanent magnet passes.

Here, one rotor core 7 has a structure having four permanent magnet bridges 72 for eight permanent magnets 6 as shown in FIG. 4B. FIG. 4C shows FIG.
An example in which the same iron core as that shown in FIG. With the above configuration, the permanent magnet bridge 72 is configured such that (b) and (c) are arranged alternately in the stacking direction of the laminated rotor core. In other words, by reducing the number of the permanent magnet bridges 72 located between the poles, the magnetic flux density due to the stator winding magnetomotive force between the poles is reduced, thereby improving the output and reducing the noise. It is.

In this case, it is necessary to increase the required strength of the bridge between permanent magnets 72. In general, the width of the bridge between permanent magnets 72 in the radial direction is often larger than the strength for supporting the centrifugal force. Rather, it is determined by the minimum width of a die for punching a silicon steel plate as a rotor core. Conversely, if the air gap magnetic flux density due to the stator winding magnetomotive force is the same, the configuration in which the inter-permanent magnet bridges 72 are intermittently arranged in the axial direction as in the present invention is preferable. The direction width can be increased. Punching out a wide bridge can make the mold last longer and have a longer life than punching out a narrow bridge. Also, punching out a wide bridge rather than punching out a narrow bridge can provide a permanent magnet rotor in which material deterioration due to punching is small, mechanical strength is high, and iron loss is small. Although the example in which only the permanent magnet bridge 72 is intermittently arranged in the axial direction has been described above, the same effect can be exerted by forming the gap-side bridge 71 in the same shape. Although the arrangement of the figures is shown every other sheet, the arrangement of FIGS. 4B and 4C may be arranged two by two, or every three sheets. Further, the number of the permanent magnet bridges 72 can be increased or decreased, or the interval can be changed.

FIG. 5 is a sectional view in the rotating direction of a permanent magnet rotating electric machine according to another embodiment of the present invention.

Here, only the part of the rotor which is an improvement on FIG. 1 is shown. (A) shows the rotor assembly structure,
(B) and (c) show one sheet of the laminated rotor core.

In the figure, the same reference numerals as those in FIG. 1 indicate the same structures. Here, an example of an 8-pole permanent magnet rotor is shown.

In FIG. 5 (a), the rotor core 7 has a hole for accommodating the permanent magnet 6, a magnetic pole piece 77 forming a gap-side magnetic path of the permanent magnet, and a gap for holding the permanent magnet 6 together with the magnetic pole piece 77. It comprises a side bridge 71, an auxiliary salient pole 79 located between the permanent magnets 6 for generating reluctance torque, and a yoke 78 for passing the magnetic flux of the permanent magnet.

Here, as shown in FIG. 5 (b), one rotor core 7 is a magnetic pole piece 77, a magnetic pole piece constituting a gap side magnetic path of four sets of permanent magnets with respect to eight permanent magnets 6. The structure has a gap-side bridge 71 that holds the permanent magnet 6 together with 77 and an auxiliary salient pole 79 that is located between the permanent magnets 6 and generates reluctance torque. FIG. 5C shows an example in which the same iron core as that of FIG. With the above configuration, the pole pieces 77 are arranged alternately in the stacking direction of the laminated rotor cores. In other words, by reducing the number of the permanent magnet bridges 72 located between the poles, the magnetic flux density due to the stator winding magnetomotive force between the poles is reduced, thereby improving the output and reducing the noise. It is. If necessary, reducing the number of auxiliary salient poles 79 can also increase the effect of the present invention. In this case, the shape of the auxiliary salient pole 79 can be changed on both sides in FIG. With the configuration described above, a permanent magnet rotor having high output, high mechanical strength, and low iron loss can be provided as in the example shown in FIG. Further, since the configuration is such that a part of the rotor core is partially arranged, the weight of the permanent magnet rotating electric machine can be reduced.

Next, though not shown, the same effect can be obtained by reducing the thickness of the magnetic material of the rotor core of the permanent magnet rotating electric machine with respect to the stator core.

By using a thin magnetic material as the rotor core, the space factor in the stacking direction of the core is reduced,
Saturation occurs at a low magnetomotive force relative to the stator winding magnetomotive force. Thereby, the magnetic flux density can be suppressed, and the same effect can be exerted.

Although the above description has been given of a permanent magnet rotating electric machine, the present invention can be applied to a reluctance motor. For example, only the rotor cores shown in FIGS. By adopting a configuration that does not include it, it can be operated as a reluctance motor.

Although the above description has been given of the distributed winding stator structure, the same effect can be exerted by a rotating electric machine having a concentrated winding structure, and a rotating electric machine, a reluctance motor, and a linear motor having an axial gap. , Generators and the like. Further, the present invention can be applied to an abduction type rotary electric machine.

FIG. 6 is a block diagram showing an electric vehicle according to an embodiment of the present invention. Here, an electric vehicle is shown as an example.

The electric vehicle body 13 has four wheels 14,
It is supported by 15, 16 and 17. Since this electric vehicle is driven by the front wheels, the permanent magnet rotating electric machine 1 is directly attached to the front axle 22. The configuration of the permanent magnet rotating electric machine 1 is the configuration shown in FIGS. The permanent magnet rotating electric machine 1 is controlled by the control device 18.
The driving torque is controlled. A battery 19 is provided as a power source of the control device 18, and power is supplied from the battery 19 to the permanent magnet rotating electric machine 1 via the control device 18, and the permanent magnet rotating electric machine 1 is driven, and the wheels 14 and 16 are driven.
Rotates. The rotation of the steering wheel 20 is the steering gear 2
The power is transmitted to two wheels 14 and 16 via a transmission mechanism including a tie rod, a knuckle arm, and the like to change the angle of the wheels.

As described above, since the permanent magnet rotating electric machine 1 is mounted, the output of the electric vehicle is low and the noise is low. Although the above description has been given with reference to the example of the electric vehicle, the same effect can be similarly exerted for the hybrid electric vehicle.
In this case, fuel efficiency can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a permanent magnet rotating electric machine according to an embodiment of the present invention in a rotation direction.

FIG. 2 is a sectional view in the axial direction of the permanent magnet rotating electric machine of FIG. 1;

FIG. 3 shows an operation principle diagram of the permanent magnet rotating electric machine of FIG. 1;

FIG. 4 is a sectional view of a permanent magnet rotating electric machine according to another embodiment of the present invention in a rotating direction.

FIG. 5 is a sectional view of a permanent magnet rotating electric machine according to another embodiment of the present invention in a rotating direction.

FIG. 6 is a block diagram showing an electric vehicle according to an embodiment of the present invention.

[Explanation of symbols]

1 ... permanent magnet rotating electric machine, 2 ... stator, 3 ... rotor, 4 ...
Stator core, 5: stator winding, 6: permanent magnet, 7: rotor core, 8: shaft, 9: end bracket, 10 ...
Bearing, 11 ... rotor side plate, 12 ... housing,
13: Electric vehicle body, 14, 15, 16, 17: Wheels, 18: Control device, 19: Battery, 20: Handle, 21: Steering, 22: Front axle, 41: Stator yoke, 42: Fixed Child salient poles, 71: gap side bridge, 72: bridge between permanent magnets, 73: salient pole core, 74
... Yoke bridge, 75 slit, 76 slit magnetic path, 77 magnetic pole piece, 78 yoke part, 79 auxiliary salient pole.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Shoichi Kawamata 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd.Hitachi Research Laboratories Co., Ltd. Hitachi, Ltd. Automotive Equipment Group (72) Inventor Osamu Koizumi 2520 Oji Takaba, Hitachinaka-shi, Ibaraki F-term within Hitachi, Ltd. Automotive Equipment Group F-term (reference) 5H619 AA01 BB01 BB06 BB13 BB15 PP02 PP06 PP08 5H621 AA03 GA01 GA04 HH01 PP02 5H622 AA03 CA02 CA06 CA13 CB04 CB05 PP03 PP10 PP11 QB04

Claims (5)

[Claims] 1. A permanent magnet comprising: a rotor having a permanent magnet annularly disposed in an iron core; and a stator having a stator winding wound around a salient pole formed by a part of the iron core. In the rotating electric machine, a gap between the rotor core and the stator core in a gap between the permanent magnets is larger than a gap between the rotor core and the stator core in a pole center of the permanent magnet. Large permanent magnet rotating electric machine. 2. A permanent magnet having a rotor having a permanent magnet annularly disposed in an iron core, and a stator having a stator winding wound around a salient pole formed of a part of the iron core. A rotating electric machine, wherein a thickness of the permanent magnet in a rotor radial direction is largest at a pole center portion, and becomes gradually thinner toward a gap between the poles. 3. A rotor having permanent magnets annularly arranged in an iron core made of laminated steel sheets, and a stator having a stator winding wound around salient poles made up of a part of the iron core. And a rotor, wherein the rotor core includes a steel plate in which a pole piece located on the stator side of the permanent magnet is intermittently missing, and all of the permanent magnets A permanent magnet rotating electric machine laminated so that at least one magnetic pole piece of the steel plate exists on the stator side. 4. The rotor core according to claim 1, wherein the rotor core is provided with a slit inwardly of the permanent magnet toward a pole center of the adjacent permanent magnets. Permanent magnet rotating electric machine. 5. An electric vehicle having the permanent magnet rotating electric machine according to claim 1.