JP2003153469A - Armature of electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an armature of electric rotating machine in which lowering of the effective quantity of the magnetic flux can be suppressed while lowering iron loss. SOLUTION: The armature of a DC motor is manufactured by winding a coil in the slot of a laminated core 15 of a plurality of core materials 20 having an insulating film 21 on the opposite end faces. Field switching frequency of the motor is not higher than 100 Hz and added weight rate of element being added to the core material 20 in the order to increase the resistivity thereof is set at about 0.5% and the thickness of the core material 20 is set at about 0.8 mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an armature for a rotary electric machine that includes a laminated core in which a plurality of core materials are laminated, and a winding is wound in a slot of the laminated core.

[0002]

2. Description of the Related Art Conventionally, an armature of a rotary electric machine such as a motor has a laminated core in which a plurality of core materials are laminated, and a winding is wound in a slot of the laminated core. A cold rolled steel plate (SPCC-SD), an electromagnetic steel plate, etc. are used as a core material which comprises this laminated core.

The cold rolled steel sheet contains Si which increases the specific resistance.
Since elements such as (silicon) and Al (aluminum) are not added, iron loss (eddy current loss) is large. Therefore, in order to reduce the iron loss and improve the motor efficiency, there is a remarkable tendency to use the electromagnetic steel sheet as the core material as compared with the cold rolled steel sheet.

[0004]

By the way, the electrical steel sheet is added with an element such as Si or Al for increasing the specific resistance in order to reduce iron loss. And, as the grade of the electromagnetic steel sheet becomes higher, and the proportion of the additional element increases,
It is known that the iron loss tends to be reduced accordingly. However, on the other hand, the effective magnetic flux amount (magnetic flux density) is reduced due to the decrease in magnetic permeability due to the increase in additives,
The torque of the motor is supposed to decrease.

Further, the addition of an element such as Si or Al that increases the specific resistance increases the hardness of the electromagnetic steel sheet, making it difficult to carry out rolling during the production of the steel sheet. Further, the hardness is so high that the die life of the press when punching the core material from the steel sheet is shortened, resulting in an increase in die cost.

Furthermore, in such a core material, the plate thickness is thin (for example, 0.5 mm, in order to reduce iron loss).
Electrical steel sheet is used. Therefore, it is necessary to punch a large number of core materials from the steel plate in order to stack the laminated core to a predetermined thickness, and the press cost is inevitably increased as the number of punching increases.

[0007] Further, the electromagnetic steel sheet is a cold-rolled steel sheet (S) which has a general requirement of sheet thickness accuracy for magnetic annealing to align axes of easy crystal magnetization, application of an insulating film on the surface of the steel sheet, and improvement of lamination space factor.
The material cost is high because the hardness is higher than that of PCC-SD, etc., and the hardness is high, which makes it difficult to perform rolling during steel sheet production and the thin sheet thickness increases the number of times of rolling.

An object of the present invention is to provide an armature for a rotary electric machine which can suppress a decrease in effective magnetic flux while reducing iron loss.

[0009]

In order to solve the above problems, the invention according to claim 1 is provided with a laminated core in which a plurality of core materials having insulating coatings on both end faces are laminated, and the laminated core is provided. In the armature of the rotating electric machine in which the winding is wound in the slot, the magnetic field switching frequency of the rotating electric machine is 100H.
z or less and 0.3% by weight of the element added to the core material in order to increase the specific resistance of the core material.
The gist is that the plate thickness of the core material is set to 0.74 mm or more and 0.84 mm or less while being set to 0.9% or less.

A second aspect of the present invention provides the armature for a rotating electric machine according to the first aspect, wherein the element that increases the specific resistance of the core material is at least one of silicon and aluminum.

(Operation) According to the invention described in claim 1 or 2, the weight addition ratio of the element added to the core material is adopted for the ordinary core material in order to increase the specific resistance of the core material. Smaller than electromagnetic steel sheets 0.3% or more, 0.9
% Or less, and the thickness of the core material is 0.74 mm, which is larger than the electromagnetic steel plate used for ordinary core materials.
As described above, it is 0.84 mm or less. Here, when the magnetic field switching frequency of the rotating electric machine is 100 Hz or less, if the weight addition rate of the element added to the core material is within the set range, the transparency of the core material (magnetic steel sheet) itself is substantially the same. It has been confirmed by the present applicant that the decrease in magnetic susceptibility is suppressed and the decrease in effective magnetic flux amount (magnetic flux density) is suppressed. At this time, the applicant has also confirmed that the core material (electromagnetic steel sheet) itself is sufficiently reduced in iron loss. In particular, since the core material has insulating coatings on both end surfaces, iron loss as a laminated core is also reduced.

Further, since the weight addition ratio of the element for increasing the specific resistance added to reduce the iron loss is relatively small, the hardness increase of the core material (electromagnetic steel sheet) is suppressed. Therefore, the rolling process at the time of manufacturing the steel sheet is facilitated. Further, since the hardness is low, the die life of the press when punching the core material from the steel sheet is extended, and the die cost is reduced.

Furthermore, since the thickness of the core material is relatively large and the increase in hardness of the core material (electromagnetic steel sheet) is suppressed, the material cost can be reduced by reducing the load of rolling. Further, since the thickness of the core material is relatively large, the number of core materials that need to be punched out from the steel sheets to be laminated to a predetermined thickness as a laminated core is reduced, and the number of punching times is reduced, and the press cost is also reduced. To be done.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 2, a DC motor 1 as a rotary electric machine includes a motor housing 2, and the motor housing 2 includes a bottomed cylindrical yoke 3 and an end frame 4. A bearing recess 5 is provided on the bottom of the yoke 3, and a bearing 6 is fixed in the bearing recess 5. A pair of magnets 8 and 9 are fixedly provided on the inner surface of the yoke 3.

The end frame 4 is fixed to the opening of the yoke 3, and the armature 10 as an armature is housed in the space formed by the end frame 4 and the yoke 3. A bearing recess 11 is provided at the center of the end frame 4, and the through hole 1 is formed in the bearing recess 11.
2 is formed. In addition, the bearing recess 11 has a bearing 13
Is fixed, and the rotating shaft 14 of the armature 10 is rotatably supported by the bearing 13 and the bearing 6 fixed to the yoke 3.

A laminated core 15 is fixed to the rotary shaft 14 of the armature 10, a winding 16 is wound around the laminated core 15, and a winding end of the winding 16 is also commutator 17 fixed to the rotary shaft 14. Is connected to the commutator piece 17a.

As shown in FIG. 3, the laminated core 15 is formed by laminating a plurality of core materials 20. The core material 20 is radially from its central portion, and
A plurality of teeth pieces 21 (eight in this embodiment) are formed to extend at equal angular intervals. Protrusions 22 that extend in an arc shape on both sides are formed at the tip ends of the tooth pieces 21. Further, in the central portion of the core material 20, the rotating shaft 14
A through hole 23 is provided for penetrating. The tooth piece 21 formed on the core material 20 is
The space that forms the tooth 15a of the laminated core 15 and that is formed between the adjacent teeth 15a forms the slot 15b. The winding 16 is wound in the slot 15b of the laminated core 15.

As shown in the sectional shape of FIG. 1, the core material 20 is formed of an electromagnetic steel plate having a plate thickness of, for example, about 0.8 mm. In order to increase the specific resistance of the core material 20, for example, approximately 0.5% is added to the core material 20.
Elements such as Si and Al are added at the weight addition ratio of. In addition, the weight addition rate here represents the ratio of the above-mentioned elements added to the core material 20 by a weight ratio (%). Insulating films 21 are provided on both end surfaces of the core material 20.

Here, FIG. 8 shows that the weight addition ratio of elements such as Si and Al added to the electromagnetic steel sheet (core material) in order to increase the specific resistance and the magnetic field switching frequency of the motor are 5
It is a graph which experimentally calculated | required each relationship with the iron loss in 0 Hz, and the amount of effective magnetic flux (magnetic flux density). In addition, FIG. 9 shows experimentally the efficiency at the rated output (motor rated point efficiency) of the motor equipped with the above-mentioned weight addition rate and the armature configured by the laminated core in which the electromagnetic steel sheets (core material) are laminated. It is a graph. The thickness of the electromagnetic steel sheet (core material) is approximately 0.
It is assumed to be 8 mm.

As is clear from the figure, when the weight addition ratio is 0.3% or more and 0.9% or less, the iron loss and the amount of magnetic flux are well balanced, and the motor rated point efficiency is 0.665 (6
6.5%) or more. Particularly, in the vicinity of the above-mentioned weight addition ratio of 0.5%, the balance of the iron loss and the amount of magnetic flux is optimum, and the motor rated point efficiency occupies approximately the maximum value. As described above, in the core material 20 of the present embodiment, the weight addition rate of the elements such as Si and Al added to increase the specific resistance is set to about 0.5%.

Incidentally, the above-mentioned weight addition rate is 0.9%.
If it exceeds, the hardness of the electromagnetic steel sheet (core material) will increase,
The rolling process at the time of manufacturing the steel sheet becomes difficult, which leads to an increase in cost.

Next, the characteristics of the core material 20 (electromagnetic steel sheet) manufactured in this way will be described below.
FIG. 4 is a graph showing the relationship between the frequency (the magnetic field switching frequency of the motor) and the magnetic flux density when the magnetic field is constant for steel plates formed of each material. As a steel plate material, a cold rolled steel plate having a thickness of 0.5 mm SPCC-SD, 0.8
mm SPCC-SD, electromagnetic steel plate thickness 0.5 mm
50A1000, 50A600, 50A470, 50
A270, an experimentally obtained steel plate adopted in the present embodiment is shown. In the electromagnetic steel sheet, the lower number indicates the grade, and the smaller the number, the higher the grade. That is, the smaller this number is, the larger the weight addition rate of the electromagnetic steel sheet is.

As is clear from the figure, in the steel plate adopted in this embodiment, the magnetic field switching frequency of the motor is 100.
The magnetic flux density below Hz is slightly lower than the plate thickness of the electromagnetic steel plate 50A1000 of 0.5 mm by the plate thickness effect of the plate thickness being approximately 0.8 mm. However,
For magnetic steel sheets of grade 50A600 or higher, the magnetic flux density is high and good characteristics are exhibited. In addition,
Due to the increase in iron loss due to the large plate thickness, when the magnetic field switching frequency of the motor is 100 Hz or less, the magnetic flux density is at the same level as that of the cold rolled steel plate SPCC-SD having a plate thickness of 0.5 mm.

FIG. 5 is a graph showing the relationship between the frequency when the magnetic field is constant (the magnetic field switching frequency of the motor) and the iron loss for the steel plates formed of each material.
FIG. 6 is an enlarged view showing a region B on the low frequency side of FIG. As a steel plate material, a cold rolled steel plate S having a plate thickness of 0.5 mm
PCC-SD, 0.8 mm cold rolled steel plate SPCC-
SD, 0.5 mm thick electromagnetic steel plates 50A1000, 50
A600, 50A470, 50A270, Thickness 0.35
mm electromagnetic steel plate 35A440, which is experimentally obtained for the steel plate adopted in this embodiment.

As is clear from the figure, in the steel plate adopted in this embodiment, the magnetic field switching frequency of the motor is 100.
The iron loss at a frequency of Hz or less is 0.
Compared to 5 mm, it is slightly increased due to the plate thickness effect of the plate thickness being approximately 0.8 mm. And plate thickness 0.5
The core loss is equivalent to that of the cold rolled steel plate SPCC-SD of mm.

By the way, when the core materials are laminated to form a laminated core, by providing an insulating film on both end surfaces of the core material (electromagnetic steel sheet), iron loss due to contact conduction between the core materials can be reduced. It has been known. In this embodiment, the insulating film 21 is provided on both end surfaces of each core material 20 to form the laminated core 1
The iron loss as No. 5 (armature 10) is reduced. The effect of reducing the iron loss of the laminated core 15 (armature 10) is shown in FIGS. 6 and 7. Note that FIG.
[Fig. 3] is a graph obtained by experimentally determining iron loss as an armature composed of a laminated core in which steel plates of respective materials are laminated.
Further, FIG. 7 is a graph in which the rated point efficiency of a motor including an armature configured by a laminated core in which steel plates of respective materials are laminated is experimentally obtained. As a steel plate material, the plate thickness is 0.
5mm cold rolled steel plate SPCC-SD, plate thickness 0.5mm
The electromagnetic steel sheet 50A1000, and the steel sheet used in the present embodiment are experimentally obtained.

As described above, the iron loss as a single steel plate is
The steel plate adopted in this embodiment and the cold rolled steel plate SPCC-SD having a plate thickness of 0.5 mm were at the same level. However, as is clear from FIG. 6, due to the effect of the insulating film 21 provided on the core material 20, the iron loss as the armature 10 is reduced to the level of the electromagnetic steel sheet 50A1000.

As is apparent from FIG. 7, the rated point efficiency of the DC motor 1 provided with the armature 10 is about 0.65% lower than that of the electromagnetic steel sheet 50A1000, and is practically equivalent. It is about 1.8% higher than that of the cold rolled steel plate SPCC-SD of 0.5 mm.

As described in detail above, according to this embodiment, the following effects can be obtained. (1) In the present embodiment, the weight addition ratio of elements such as Si and Al added to the core material 20 in order to increase the specific resistance of the core material 20 is higher than that of an electromagnetic steel sheet used for a normal core material. The core material 20 has a thickness of 0.8 mm, which is larger than that of an electromagnetic steel sheet used as a normal core material. Here, by setting the magnetic field switching frequency of the DC motor 1 to 100 Hz or less, a decrease in the magnetic permeability of the core material 20 itself is substantially suppressed, and a decrease in the effective magnetic flux amount (magnetic flux density) can be suppressed. it can. Therefore, it is possible to suppress the decrease in the motor torque due to the decrease in the effective magnetic flux amount.

At this time, it is sufficient to substantially reduce the core loss of the core material 20 itself. In particular, since the core material 20 has the insulating coatings 21 on both end surfaces, the iron loss of the laminated core 15 can be reduced. Therefore, it is possible to suppress a decrease in motor efficiency due to the increase in iron loss.

Further, since the weight addition ratio of the element for increasing the specific resistance added to reduce the iron loss is relatively small, the increase in hardness of the core material 20 (electromagnetic steel sheet) is suppressed. Therefore, the rolling process at the time of manufacturing the steel sheet can be easily performed. In addition, since the hardness is low, from steel plate to core material 2
The die life of the press when punching out 0 is extended, and the die cost can be reduced.

Furthermore, since the thickness of the core material 20 is relatively large and the hardness of the core material 20 (electromagnetic steel sheet) is suppressed from increasing, it is possible to reduce the material cost by reducing the load of rolling. Since the thickness of the core material 20 is relatively large, the number of core materials 20 that need to be punched out from the steel sheets in order to stack the laminated core 15 to a predetermined thickness is also reduced, and the number of punches is reduced,
Press costs can also be reduced.

The embodiment of the present invention is not limited to the above embodiment, but may be modified as follows. In the above embodiment, the weight addition rate of the element added to the core material 20 (electromagnetic steel sheet) to increase the specific resistance is set to about 0.5%, but if the magnetic field switching frequency of the motor is 100 Hz or less. For example, it may be set to 0.3% or more and 0.9% or less. It has been confirmed by the present applicant that the same effects as those of the above-described embodiment can be obtained within this range.

In the above embodiment, the core material 20
The thickness of the (electromagnetic steel sheet) was set to about 0.8 mm, but if the magnetic field switching frequency of the motor is 100 Hz or less,
It may be set to 74 mm or more and 0.84 mm or less. It has been confirmed by the present applicant that the same effects as those of the above-described embodiment can be obtained within this range.

The shape of the laminated core 15 in the above embodiment is an example, and other shapes such as different numbers of teeth 15a may be adopted. The structure of the DC motor 1 in the above embodiment is an example, and other structures such as different numbers of poles (number of magnets) may be adopted.

In the above embodiment, the DC motor 1 is embodied as the rotating electric machine, but the laminated core 15 has the winding 1
As long as 6 is a rotating electric machine including the armature 10 wound around it, it may be applied to a generator.

Next, technical ideas other than the claims that can be understood from the above-described embodiments will be described below along with their effects. (A) In a laminated core of a rotary electric machine in which a plurality of core materials (20) having insulating films (21) on both end surfaces are laminated,
The magnetic field switching frequency of the rotating electric machine is 100 Hz or less, and the weight addition ratio of the element added to the core material for increasing the specific resistance of the core material is 0.3% or more and 0.9.
% Or less, and the thickness of the core material is 0.7
A laminated core of a rotating electric machine, characterized by being set to 4 mm or more and 0.84 mm or less.

(B) In the laminated core for a rotary electric machine described in (a) above, the element for increasing the specific resistance of the core material is at least one of silicon and aluminum.

(C) Having insulating coatings (21) on both end faces,
In a core material of a rotary electric machine in which a plurality of layers are stacked to form a laminated core (15), the magnetic field switching frequency of the rotary electric machine is 100 Hz or less, and the weight addition ratio of the element added to increase the specific resistance is 0. 3% or more and 0.9% or less, and a plate thickness of 0.74 mm or more, 0.8
A core material for a rotating electric machine characterized by being set to 4 mm or less.

(D) In the core material for a rotary electric machine described in (c) above, the element for increasing the specific resistance is at least one of silicon and aluminum.

According to the invention described in any one of (a) to (d) above, in order to increase the specific resistance of the core material, the weight addition ratio of the element added to the core material is set to be a normal core. It is 0.3% or more and 0.9% or less, which is smaller than the electromagnetic steel sheet used as the material, and the thickness of the core material is larger than the electromagnetic steel sheet used as the normal core material. It is set to 0.74 mm or more and 0.84 mm or less. Here, when the magnetic field switching frequency of the rotating electric machine is 100 Hz or less, if the weight addition rate of the element added to the core material is within the set range, the transparency of the core material (magnetic steel sheet) itself is substantially the same. It has been confirmed by the present applicant that the decrease in magnetic susceptibility is suppressed and the decrease in effective magnetic flux amount (magnetic flux density) is suppressed. At this time, the applicant has also confirmed that the core material (electromagnetic steel sheet) itself is sufficiently reduced in iron loss. In particular, since the core material has insulating coatings on both end surfaces, iron loss as a laminated core is also reduced.

Further, since the weight addition ratio of the element for increasing the specific resistance added for reducing the iron loss is relatively small, the increase in hardness of the core material (electromagnetic steel sheet) is suppressed. Therefore, the rolling process at the time of manufacturing the steel sheet is facilitated. Further, since the hardness is low, the die life of the press when punching the core material from the steel sheet is extended, and the die cost is reduced.

Furthermore, since the thickness of the core material is relatively large and the increase in hardness of the core material (electromagnetic steel sheet) is suppressed, the material cost can be reduced by reducing the load of rolling. Further, since the thickness of the core material is relatively large, the number of core materials that need to be punched out from the steel sheets to be laminated to a predetermined thickness as a laminated core is reduced, and the number of punching times is reduced, and the press cost is also reduced. To be done.

[0044]

As described in detail above, according to the invention described in claim 1 or 2, it is possible to suppress the decrease of the effective magnetic flux while reducing the iron loss.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a DC motor to which the embodiment is applied.

FIG. 3 is a perspective view of a laminated core to which the embodiment is applied.

FIG. 4 is a graph showing the relationship between frequency and magnetic flux density.

FIG. 5 is a graph showing the relationship between frequency and iron loss.

FIG. 6 is a graph showing iron loss as an armature for each material.

FIG. 7 is a graph showing rated point efficiencies as a motor for each material.

FIG. 8 is a graph showing each relationship between the weight addition rate and the iron loss and the magnetic flux amount.

FIG. 9 is a graph showing the relationship between the weight addition rate and the motor rated point efficiency.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... DC motor as rotary electric machine, 10 ... Armature as armature, 15 ... Laminated core, 15b ... Slot, 1
6 ... Winding wire, 20 ... Core material, 21 ... Insulating film.

Claims (2)

[Claims] 1. A laminated core (15) in which a plurality of core materials (20) having insulating films (21) on both end faces are laminated, and a winding (1) is provided in a slot (15b) of the laminated core.
In the armature of the rotating electric machine in which 6) is wound, the magnetic field switching frequency of the rotating electric machine is 100 Hz or less, and the weight addition rate of the element added to the core material to increase the specific resistance of the core material is 0.3% or more and 0.9% or less, and the thickness of the core material is 0.74 m
An armature for a rotating electric machine, wherein the armature is set to m or more and 0.84 mm or less. 2. The armature for a rotary electric machine according to claim 1, wherein the element that increases the specific resistance of the core material is at least one of silicon and aluminum.