JPH0522885A - Magnetic wedge of rotating electric machine - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to an improvement of a magnetic wedge used in a rotating electric machine, and smoothes pulsation generated in a circumferential magnetic flux distribution on the surface of an iron core, and at the same time, flows from a slot tooth portion to an adjacent slot tooth portion. (EN) A magnetic wedge that reduces leakage flux and contributes to improved characteristics such as high efficiency in a rotating electric machine. [Structure] The magnetic material layer 5a of the magnetic wedge 5 is composed of a magnetic thin wire 5.
A magnetic material such as c is laminated to form a base material and is made of a plastic material. When the magnetic wedge 5 is attached to the slot opening 2a, a cross-sectional shape in which the letter H is laid out is set so that the configuration of the magnetic wedge 5 corresponding to the vicinity of the central position of the slot opening 2a is a non-magnetic body portion. The magnetic material layer 5a is placed in the opening of the non-magnetic material layer 5b, and is integrally molded to be formed so as to match the shape of the slot opening 2a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine, and more particularly to a magnetic wedge for fixing a winding housed in a slot of a rotary electric machine iron core.

[0002]

2. Description of the Related Art In a conventional rotary electric machine iron core, a winding provided with insulation is housed in a slot provided in a stator and a rotor core, and the winding is dropped into an opening of the slot. A wedge is inserted to prevent this. However, if the wedge is made of a non-magnetic material, the circumferential magnetic reluctance value in the gap between the stator and the rotor core becomes discontinuous due to the influence of the slot opening. Therefore, pulsation occurs in the magnetic flux distribution in the circumferential direction on the surface of the iron core facing the wedge via the void, and harmonic loss increases. On the other hand, since the magnetic resistance of the slot opening is larger than the magnetic resistance of the iron core, there is a drawback that the magnetic flux concentrates on the teeth of the iron core.

As a method of solving the above-mentioned drawback, a method of using a so-called magnetic wedge in which the wedge inserted into the slot opening is made of a magnetic material is disclosed in, for example, Japanese Patent Laid-Open Nos. 63-161834 and 62-262626. It is disclosed in Japanese Patent Publication No. The former magnetic wedge is shown in FIG. 7, and the latter magnetic wedge is shown in FIG.
The former has a two-layer structure in which a magnetic material layer 5a formed by molding magnetic iron powder with a plastic material and a reinforcing agent such as glass fiber are integrally molded as a non-magnetic material layer 5b. being called. On the other hand, the latter is characterized in that a plurality of magnetic fine wires 5c are arranged in parallel at a predetermined interval and an angle, and are alternately laminated with different inclination angles and molded with a plastic material. being called.

[0004]

In the above-mentioned prior art, in the former case, the magnetic flux layer 5a of the magnetic wedge 5 magnetically short-circuits the adjacent iron core tooth portions 1a and 1b, so that the leakage magnetic flux Φe.
(Magnetic flux flowing from a certain iron core tooth portion to an adjacent iron core tooth portion) is increased and effective magnetic flux (Φt + Φw) is reduced, so that there is a drawback such as a decrease in torque. On the other hand, in the latter case, there is a problem in joining adjacent magnetic fine wire layers by a plastic material, and there was concern about the mechanical strength of the wedge 5 itself, such as the magnetic fine wire 5c peeling off. This defect is caused by the magnetic layer 5 forming the magnetic wedge 5.
In order to increase the relative magnetic permeability of a, it becomes more remarkable as the space factor of the magnetic wire 5c in the magnetic layer 5a is increased. Therefore, in the magnetic layer 5a using the magnetic thin wires 5c as a base material, the relative magnetic permeability of the magnetic layer 5a cannot be increased to a desired value, so that the circumferential magnetic flux distribution on the surface of the iron core 10 cannot be sufficiently smoothed. There was a flaw.

The present invention has been made in view of the above points, and the mechanical strength of the wedge itself is sufficiently large, and the pulsation generated in the magnetic flux distribution in the circumferential direction on the surface of the iron core facing the magnetic wedge through the void is generated. An object of the present invention is to provide a magnetic wedge that can be smoothed and reduce leakage flux to contribute to improved characteristics such as high efficiency in a rotating electric machine.

[0006]

The above object is to provide a magnetic wedge of a rotating electric machine mounted in a slot opening, the magnetic wedge being a magnetic layer made of a magnetic material and a plastic material, and a plastic material being a non-magnetic material. A non-magnetic material layer formed of a non-magnetic material layer, and when the magnetic wedge is attached to the slot opening portion, the structure of the magnetic wedge corresponding to the vicinity of the center position of the slot opening portion becomes the non-magnetic material portion. The cross-sectional shape of the non-magnetic material layer that constitutes the letter H has a horizontal shape, and the magnetic material layer is placed in the opening of the non-magnetic material layer having the same H-shaped cross-sectional shape and integrally molded. To be

[0007]

In the magnetic wedge according to the present invention, the non-magnetic material layer forming the magnetic wedge has an H-shaped cross-section, so that the external force such as the centrifugal force and the electromagnetic force acting on the winding housed in the slot can be prevented. And has sufficient mechanical strength. Further, by arranging the magnetic material layer in the opening of the non-magnetic material layer having the same H-shaped cross-sectional shape, the pulsation generated in the magnetic flux distribution in the circumferential direction on the surface of the iron core facing the magnetic wedge via the void is markedly increased. It can be smoothed. Further, the leakage magnetic flux that tries to flow from the iron core tooth portion to the adjacent iron core tooth portion through the magnetic layer of the wedge is the same as that of the wedge portion when the wedge is attached to the slot opening portion. Since the magnetic resistance of the non-magnetic material portion is increased by the above configuration, the flow can be suppressed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a main part of a rotary electric machine showing an embodiment of the present invention. In the figure, a winding 4 provided with insulation 3 is housed in a slot 2 provided in a stator core 1. A magnetic wedge 5 is inserted into the opening 2a of the slot 2 to support and fix the winding 4. The magnetic wedge 5 is fixed by grooves provided in the side wall portions of the iron core teeth 1a and 1b, holds the magnetic wedge 5 itself, and supports and fixes the winding 4. Reference numerals 6 and 7 are spacers for adjusting the height direction dimension of the winding wire 4 in the slot 2, and 8 and 9 are spacers for adjusting the width direction dimension of the slot 2 and the winding wire 4. A rotor core 10 is rotatably supported in an inner hole in the stator core 1 with a gap 11 therebetween.

FIG. 2 shows details of the magnetic wedge 5 according to the present invention. The magnetic wedge 5 has a magnetic material layer 5a made of a magnetic material and a plastic material in an opening of a nonmagnetic material layer 5b having a cross-sectional shape with the letter H of the alphabet made of a non-magnetic material made horizontal.
Has a structure that is placed. Magnetic wedge 5 in the figure
The magnetic material layer 5a is formed by laminating a magnetic material such as the magnetic wire 5c as a base material and using a plastic material. Here, the magnetic substance such as the magnetic thin wire 5c has a magnetic anisotropy for the purpose of rectifying the flow of the magnetic flux incident on the magnetic layer 5a.
The layers are stacked with a certain angle in the direction indicated by the arrow in FIG. Then, a plastic material is contained and disposed in the opening of the nonmagnetic layer 5b.

According to the present invention, the non-magnetic layer 5b forming the magnetic wedge 5 has an H-shaped cross-section, so that the external force such as the centrifugal force acting on the winding 3 housed in the slot 2 can be prevented. And have sufficient mechanical strength. Further, since the magnetic layer 5a is arranged in the opening of the non-magnetic layer 5b having the H-shaped cross section, even if the amount of the magnetic wires 5c is increased to increase the space factor of the magnetic layer, the magnetic layer 5a is magnetic. There is an effect that the body layer 5a does not peel off.
In the illustrated example, the number of magnetic layers 5a is two,
Even if the number of the magnetic layers 5a is plural, this effect remains the same.

Next, the magnetic effect when the magnetic wedge 5 according to the present invention is applied to a rotary electric machine will be described in detail.

As shown in FIG. 1, by using the magnetic wedge 5 according to the present invention shown in FIG. 2, the stator core tooth portion 1a is formed.
And 1b to the void portion 11, the effective magnetic flux of the magnetic wedge layer 5 of the magnetic wedge 5 in addition to Φt from the iron core tooth portions 1a and 1b.
Φw passing through a will also flow. That is, iron core tooth part 1
The magnetic flux Φw incident on the magnetic material layer 5a of the magnetic wedge 5 from the side surfaces of a and 1b is a magnetic material (FIG. 1 in FIG. 1) laminated at a predetermined angle with respect to the radial direction (r direction in FIG. 1) of the rotating electric machine. The magnetic flux is rectified by the magnetic thin wire 5c as an example) so that the magnetic flux flows in the direction of the void portion 11, so that the effective magnetic flux increases. Further, since the magnetic layer 5a is firmly held by the non-magnetic layer 5b having the cross-sectional shape with the letter H forming the magnetic wedge 5 as the side, the space factor of the magnetic layer 5a is improved. it can. Therefore, since the relative magnetic permeability of the magnetic layer 5a can be increased, the magnetic flux can easily pass through the magnetic layer 5a, and the magnetic flux Φw that passes through the magnetic wedge 5 and flows into the gap 11 further increases. Therefore, the stator core teeth 1a,
1b In addition to the effective magnetic flux Φt from the surface portion, the total magnetic flux amount of the void portion 11 is increased by the magnetic flux Φw passing through the magnetic wedge 5, and the circumferential magnetic flux on the surface portion of the iron core 10 facing the magnetic wedge 5 via the void portion 11 is increased. The pulsation of the distribution is further smoothed.

FIG. 3 is a diagram specifically showing the effect of the present invention, and is a diagram showing the distribution of the magnetic flux density on the surface of the core facing the wedge 5 only for one slot pitch. In the figure, the solid line shows the magnetic flux distribution when the magnetic wedge 5 according to the present invention is applied to the slot opening, and the broken line shows the magnetic flux distribution when the conventional wedge 5 is applied. It can be seen that the smoothing of is achieved.

On the other hand, the leakage magnetic flux Φe flowing from the iron core tooth portions 1a to 1b, which has been a problem in the past, has a low relative magnetic permeability (a large magnetic resistance) in the middle of the direction of the magnetic path of Φe (θ direction in FIG. 1). The existence of the non-magnetic layer 5b significantly hinders its distribution. Here, since the non-magnetic layer 5b is present, it is feared that the circumferential magnetic flux distribution may be pulsated, but this is effective by improving the magnetic space factor of the magnetic wedge 5. There is no problem because the magnetic flux Φw can be increased.

Next, as another embodiment of the present invention,
When the magnetic iron powder is contained in the plastic material forming the magnetic material layer 5a in the magnetic wedge 5, the magnetic material space factor of the magnetic material layer 5a can be more finely adjusted, and the relative permeability of the magnetic material layer 5a can be adjusted. The magnetic susceptibility can be set to a desired value. Therefore, the pulsation of the circumferential magnetic flux distribution on the surface of the iron core 10 facing the magnetic wedge 5 can be smoothed more effectively.

As another embodiment of the present invention,
A plurality of magnetic fine wires 5 are formed on the magnetic body forming the magnetic layer 5a.
When c is used, the cross-sectional shape of the magnetic layer 5a can be easily processed into any shape. Therefore, the cross-sectional shape of the magnetic layer 5a can be formed in a rectangular shape, a trapezoidal shape, a triangular shape, a circular shape, a convex shape, or the like as needed.

The magnetic thin wire 5c may be a net-like magnetic thin wire 5d woven into a net as shown in FIG.
In this case, the structure of the non-magnetic layer 5b forming the magnetic wedge 5 is the same as that shown in FIG. The difference from the case of FIG. 2 is that, as the magnetic layer 5a forming the magnetic wedge 5, a plurality of reticulated magnetic fine wires 5d formed by reticulating the magnetic fine wires 5c are laminated in the radial direction of the rotating electric machine by using a plastic material. It's where it's configured.
By adopting the reticulated magnetic fine wire 5d, there is an effect that the mechanical strength of the magnetic wedge 5 can be further increased and the magnetic wedge 5 can be easily manufactured.

Further, if a thin iron plate is used instead of the magnetic thin wire 5c, the mechanical strength of the magnetic wedge 5 can be further increased. Here, particularly when the non-magnetic layer 5b forming the magnetic wedge 5 is made of a non-magnetic sheet such as FRP impregnated with resin, further mechanical strength of the wedge 5 can be obtained.

As the plastic material forming the magnetic wedge 5 according to the present invention, either an organic plastic material or an inorganic plastic material may be used depending on the purpose. By using these plastic materials, the cross-sectional shape of the magnetic wedge 5 itself can be formed according to the shape of the slot opening 2a, like the cross-sectional shape of the magnetic layer 5a.

The magnetic wedge 5 of the present invention having the above characteristics may be manufactured as follows. First, a non-magnetic layer 5b made of the plastic material and glass fiber, face cloth or paper
As shown in FIG. 5, the magnetic layer 5a is covered and integrated with the magnetic layer 5a. However, at this time, the magnetic layers 5a and 5a
The non-magnetic layer 5b is inserted between it and a '. By heating and compressing this, the shape shown in FIG. 6 is obtained.
Then, by processing both ends of the shape shown in the figure into a desired shape, for example, the magnetic wedge 5 having the shape shown in FIG. 2 can be obtained.

As described above, the magnetic wedge 5 of the present invention is
By forming the magnetic layer 5a by stacking magnetic layers,
Since the magnetic resistance in the thickness direction of the wedge 5 is small (the relative magnetic permeability is large) and the magnetic resistance in the width direction is large (the relative magnetic permeability is small), it has magnetic anisotropy. It is effective in smoothing the pulsation generated in the circumferential magnetic flux distribution on the surface of the iron core 10 facing the wedge 5, and further, by providing the nonmagnetic layer 5b in the magnetic path of the leakage magnetic flux Φe, Φe is reduced. .

In this embodiment, the description has been made mainly on the stator core side of the rotating electric machine, but it is needless to say that the same effect can be obtained even when the wedge according to the present invention is used on the rotor core side. Nor. Further, it is possible to use both the stator core side and the rotor core side at the same time.

[0024]

As described in detail above, according to the present invention,
By using the magnetic wedge, the pulsation of the circumferential magnetic flux distribution on the iron core surface portion facing the magnetic wedge via the void is smoothed, and the leakage magnetic flux between the adjacent iron core tooth portions is suppressed. It is possible to achieve improved characteristics such as higher efficiency.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a rotating electric machine showing an embodiment of the present invention.

FIG. 2 is a detailed perspective view of a magnetic wedge according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an effect of one embodiment of the present invention.

FIG. 4 is a detailed cross-sectional view of a magnetic wedge according to another embodiment of the present invention.

FIG. 5 is an explanatory view showing a magnetic layer and a non-magnetic layer that form a magnetic wedge.

FIG. 6 is an explanatory view showing a magnetic material layer and a non-magnetic material layer forming a magnetic wedge after heating and compression.

FIG. 7 is a cross-sectional view of a main part of a rotating electric machine in which a slot is provided with a composite magnetic wedge.

FIG. 8 is a cross-sectional view of a main part of a rotating electric machine in which a slot is provided with a magnetic anisotropic wedge.

[Explanation of symbols]

1 ... Stator core, 1a, 1b ... Core teeth, 2 ... Slot,
4 ... Winding, 5 ... Magnetic wedge, 5a ... Magnetic layer of magnetic wedge, 5b
... non-magnetic layer of magnetic wedge, 5c ... magnetic wire, 10 ... rotor core, 11 ... void.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenzo Kajiwara             3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture Stock Association             Hitachi, Ltd.Hitachi factory

Claims (6)

[Claims] 1. A stator of a rotating electric machine, in which a stator and a rotor are opposed to each other via a gap, and a coil winding housed in a plurality of slots provided in a rotor core, are supported and fixed in the slot. In order to achieve this, in a magnetic wedge of a rotary electric machine mounted in the slot opening, the magnetic wedge is composed of a magnetic material layer made of a magnetic material and a plastic material, and a non-magnetic material layer made of a non-magnetic material. So that the structure of the magnetic wedge corresponding to the vicinity of the center position of the slot opening becomes a non-magnetic material part when the is attached to the slot opening, With the same structure
A magnetic wedge for a rotary electric machine, wherein the magnetic material layer is arranged in an opening of a non-magnetic material layer having a die cross-sectional shape and integrally molded. 2. The magnetic material layer of the magnetic wedge according to claim 1, wherein the magnetic material is composed of a plurality of magnetic fine wires laminated at a predetermined angle with respect to the radial direction of the rotating electric machine, and the plastic material. A magnetic wedge for a rotating electric machine, characterized by being made of a mixture. 3. The magnetic material layer of the magnetic wedge according to claim 1, wherein the magnetic material is formed by laminating a plurality of reticulated magnetic wires at a predetermined angle with respect to the radial direction of the rotating electric machine and the plastic material. A magnetic wedge for a rotating electric machine, which is made of a mixture with. 4. The magnetic material layer of the magnetic wedge according to claim 1, wherein the magnetic material layer is made of a plurality of thin iron plates laminated at a predetermined angle with respect to a radial direction of the rotating electric machine, and the plastic material. A magnetic wedge for a rotating electric machine, characterized by being made of a mixture. 5. A magnetic wedge for a rotating electric machine according to claim 1, wherein the plastic material forming the magnetic layer contains magnetic iron powder. 6. The non-magnetic material layer of the magnetic wedge according to claim 1, wherein the non-magnetic material layer is made of a mixture of a non-magnetic sheet and a plastic material impregnated with a resin for fixing the non-magnetic sheets. The magnetic wedge of the rotating electric machine.