JPH07222382A - High frequency motor - Google Patents

Abstract

PURPOSE:To obtain a high speed, high output high frequency motor having high starting torque by employing a high frequency electromagnetic steel plate having a specific thickness, principally composed of iron with the contents of components other than iron being set at a specific ratio, for at least one of armature core or field core. CONSTITUTION:A high frequency electromagnetic steel plate of 0.25 mm thick or less, principally composed of iron with the content of components other than iron being set at 1wt.% or less, is employed for at least one of armature core 1 or field core. Consequently, high flux density driving and high speed operation are realized and since the motor core can be machined with high accuracy, the motor gap can be reduced and high output can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating machine, a linear actuator and the like.

[0002]

2. Description of the Related Art High-speed motors are being used recently in order to increase the output of compressors, processing machines and motors.
To drive a high-speed motor, high-frequency excitation is performed according to a high rotation speed, and this is a part of a high-frequency motor that is driven at a high frequency.

Such high-speed motors, that is, high-frequency motors, are being studied because they can be made compact and have high output even in electric vehicles. One of the problems with this electric vehicle is the lack of acceleration. That is, the starting torque of the motor is insufficient. In this case, the motor core is required to have a low frequency characteristic, and particularly to have a high magnetic flux density. That is, a motor using an electromagnetic steel plate that can be used at a low frequency and a high magnetic flux density and has a low high frequency iron loss is optimal.

Since such a high-frequency motor has a high frequency and thus has a high iron loss, a high electrical resistance and a thin material are used. For example, an electromagnetic steel sheet of 3 wt% Si of 0.2 mm or less and an electromagnetic steel sheet of 6.5 wt% Si of 0.35 mm or less are used.

However, since they have a large amount of Si, their saturation magnetization is 3 wt% Si-Fe, which is 6.5 wt% Si, as compared with pure iron.
-Fe decreases about 16%. Therefore, the motor output, especially the torque at motor startup, is proportional to the square of the magnetic flux density, so the output is 3% by weight Si-Fe 11% compared to pure iron.
It decreases by about 30% at 6.5 wt% Si-Fe. For this reason, there is a strong demand for a motor that uses an electromagnetic steel sheet that can be used with a magnetic flux density as high as possible to achieve high output and miniaturization.

Even if the magnetic steel sheet used for the motor core is a high magnetic flux density material, if the iron loss is large, heat is generated in the motor, so that the motor cannot be used with a high magnetic flux density, and eventually high output cannot be achieved. Therefore, in order to increase the output of the motor, it is important to reduce the iron loss of the motor. In high-speed motors, increasing iron loss due to spatial harmonics generated in the core near the gap between the rotor and stator is also a problem, and lowering iron loss in the core near this gap also leads to higher motor output. Connect Further, since the magnetic flux density of the core near the gap, which is a problem due to the increase in iron loss, directly affects the output, it is also necessary to be able to design a high magnetic flux density.

However, in order to obtain a high magnetic flux density, if the amount of Si is reduced, the iron loss increases, and conversely, if a high Si material is used for the core to reduce the iron loss, the output decreases. Therefore, the high-frequency motor that can be used with a high magnetic flux density has a limit in terms of core material.

[0008]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of providing a high-frequency motor such as a high-output high-speed motor or a high-output high-speed motor having a large starting torque.

[0009]

The gist of the present invention is as follows. (1) Use a high-frequency electromagnetic steel sheet having a plate thickness of 0.25 mm or less, a main component of iron, and a content of components other than iron of 1% by weight or less for at least one of an armature core or a field core. A high-frequency motor characterized by the fact that (2) Saturation magnetization 2.1T or more, 100Hz, 1.5
A high-frequency motor characterized by using a high-frequency electromagnetic steel sheet having an iron loss of T of 4 W / kg or less for at least one of an armature core and a field core. (3) An electromagnetic steel sheet having an interlayer resistance of 1 Ωcm ² / sheet or more is used for at least one of the armature core and the field core (1)
Alternatively, the high frequency motor of (2). (4) The high frequency motor of (1), (2) or (3), which has a core made of a non-oriented electrical steel sheet. (5) The high frequency motor of (1), (2) or (3), which has a core formed by rolling and stacking grain-oriented electrical steel sheets.

(6) An electromagnetic steel sheet having a plate thickness of 0.25 mm or less, a main component of iron, and a content of components other than iron of 1% by weight or less is used for at least one of an armature core and a field core. A high-frequency motor characterized by being used in the vicinity of a gap. (7) Saturation magnetization is 2.1T or more, 100Hz, 1.5
A high frequency motor using a high frequency electromagnetic steel sheet having an iron loss of T of 4 W / kg or less in the vicinity of a gap of at least one of an armature core or a field core. (8) The high frequency motor of (6) or (7), which uses an electromagnetic steel sheet having an interlayer resistance of 1 Ωcm ² / sheet or more. (9) The high frequency motor of (6), (7) or (8), which has a core made of a non-oriented electrical steel sheet. (10) The high frequency motor according to (6), (7) or (8), which has a core formed by rolling and stacking grain-oriented electrical steel sheets.

The present invention will be described in detail below. The motor may be a general rotary type, a linear type, or both types. The type of motor may be any type such as a DC motor, an induction motor, a synchronous motor, a reluctance motor, a hysteresis motor, or the like. Therefore, as a high frequency motor, any type may be used as long as the core is excited at high frequency. The armature is a rotor of a DC motor with a brush, a synchronous machine, a stator of a brushless DC motor, a reluctance or the like, and is excited by a high frequency in a high frequency motor such as a high speed motor. The vicinity of the core gap of the motor means a portion where spatial harmonics are generated due to the slots of the core and the like. In the present invention, the core means an armature core, a field core or a field yoke.

The magnetic steel sheet used in the motor of the present invention contains iron as a main component, and the content of other than iron such as Si, C and Mn is 1% or less by weight. Therefore, the saturation magnetization is 2.1 T or more. The main components other than iron are mainly Si, C, and Mn, but any component may be used as long as it has high saturation magnetization and low high-frequency iron loss. This electromagnetic steel sheet may be produced by any method such as a rolling method, a direct casting method, a forging method or the like as long as it can be manufactured. Further, the manufacturing process may include annealing, pickling, oil washing, and further adjusting the components.
The surface of the electromagnetic steel sheet is preferably an insulating film, but by annealing in an oxidizing atmosphere, an insulating film may be produced on the surface of the electromagnetic steel plate, or by another method. If there is a method capable of increasing the interlayer resistance, that method may be adopted.

The interlayer resistance can be measured by the interlayer resistance test described in the JIS C2550 electromagnetic steel sheet test method. Since the resistance between layers is preferably larger than the resistance of the material, the interlayer resistance R (Ωcm ² / sheet), the specific resistance ρ (Ωcm) of the electromagnetic steel plate, the plate width W (cm), and the plate thickness t (cm) are as follows: R >> ρW ² / t is preferable, W = 30c
ρW ^{2 where} m, t = 0.025 cm and ρ = 10 μΩcm
/T=0.36Ωxm ² / sheet, so R ≧ 1Ωcm ² /
It is preferably a sheet.

The electromagnetic steel sheet is generally polycrystalline, but a single crystal can be used. In the case of a polycrystal, the distribution of the easy axis of magnetization <100> of the crystal is preferably suitable for the magnetic circuit used. For example, for a rotating machine, it is preferable that the axis is non-directional and the easy axis of magnetization <100> is relatively distributed. However, the grain-oriented electrical steel sheet having a low iron loss may be rotated by 90 ° so that the core has a non-directional function. The rotation angle of the stacking may be other than 90 °. For example, 90 ° or less, 90 ° or more and 180
There is a degree of rotation such as less than or equal to several degrees, and several sheets may be rotated. The plate thickness needs to be large enough to suppress loss due to eddy current in order to withstand high frequency use. Si etc. is 1
% Of the conventional electromagnetic steel plate of 0.35 mm or more, the eddy current that can expect the effect of the present invention can be reduced to half or less, which is about 0.7 times 0.35 mm, which is 0.25.
Must be less than or equal to mm. The plate thickness is measured with a micrometer or a caliper if it is a substantially smooth material, but if the smoothness is low, a gravimetric method obtained from the weight and density may be used.

The motor of the present invention is a motor that excites at a high frequency. Generally, a motor is often used at a commercial frequency of 50 Hz or 60 Hz, but in order to increase the output of the motor or reduce the size of the motor for the purpose of the present invention, the excitation frequency of the motor core should be twice the commercial frequency or more. Need to be The iron loss is preferably 4 W / kg or less at 100 Hz and 1.5 T.

[0016]

【Example】

[Example I] A commercially available non-oriented electrical steel sheet 50A130 as an example of a high-frequency electrical steel sheet used in the motor of the present invention.
0 to 25 μm by polishing, 95% nitrogen, 5 hydrogen
Table 1 shows the results of comparison between the conventional material and the material that has been subjected to strain relief annealing at 750 ° C. in a 50% atmosphere. Large saturation magnetization, 1kHz
The iron loss W _10/1000 at 1T is the same level as 6.5% Si-Fe.

[0017]

[Table 1]

[Embodiment II] An induction motor using the following electromagnetic steel sheet is used as a drive motor for an electric vehicle. Magnetic steel sheet with iron as the main component, Si less than 1 wt% is rolled to 0.03 mm, and the surface is coated with the organic insulating film that is usually applied to non-oriented electrical steel sheets. This electromagnetic steel sheet was punched and rolled into an atmosphere of 95% nitrogen and 5% hydrogen,
Strain relief annealing is performed at 750 ° C.

An induction motor type high speed motor using this material as a core has a core close to that of pure iron, is a highly saturated magnetized material, and can be used with a high magnetic flux density. Therefore, the magnetic flux density of the induction motor can be increased at the time of starting. The starting torque can be increased.
For example, since the product of the present invention has a saturation magnetization of 2.1 T or more, it is (2.1 / 1.8) ² = 1.2.0 as compared with the case of using 6.5% Si-Fe (saturation magnetization 1.8 T). It can be estimated that the starting torque can be increased 36 times, and it can be estimated that the starting torque can be increased 1.1 times even with the conventional electromagnetic foil (saturation magnetization 2.0T). In constant-speed operation, the motor operates as a high-speed motor, but the efficiency is good because of low iron loss. Therefore, an electric vehicle using this motor has good acceleration and high efficiency.

[Embodiment III] FIG. 1 shows an induction motor type high speed motor. Reference numeral 1 is an armature core, and 1'is a tooth of the armature core. The following electromagnetic steel sheets were used as the armature core material. Armature winding 4 for 1'teeth
Is wound.

An electromagnetic steel sheet containing iron as a main component and having Si of 1 wt% or less to 0.03 mm by rolling is punched or wound into a nitrogen 95% hydrogen 5% atmosphere at 750 ° C. for 2 hours and then air. Anneal at 400 ° C. The first-stage annealing removes processing strain and causes the grain growth of electrical steel sheets, and the second-half annealing is a process generally called bluing, which forms an oxide film on the surface film to form an insulating film. is there.

The rotor is composed of the outermost peripheral core 2, the inner core 3 and the secondary conductor 5. The outermost peripheral core 2 uses the same material as the armature core material, and increases the iron loss due to spatial harmonics. It is also suitable for increasing the output of a motor because it suppresses the noise and can use a high magnetic flux density. The inner core 3 is cut out from an electromagnetic thick plate having high magnetic flux density and high electrical conductivity.

In this motor, since the core material is a low iron loss material particularly for high frequencies, iron loss in the core due to spatial harmonics generated in the gap portion is reduced, and further, the core material has high saturation magnetization. Therefore, high magnetic flux density drive is possible,
Motor output is increased.

[0024]

The motor of the present invention uses a magnetic steel sheet having a high saturation magnetization and a low high-frequency iron loss as a core material, so that it can be driven at a high magnetic flux density and can be operated at a high speed, resulting in a small size and a high output. Conventionally, in high frequency motors such as high speed motors, 6.
Although 5% Si-Fe and 3% Si electromagnetic foils are used, they are difficult to roll, require high technology for manufacturing, are expensive, and are expensive to manufacture the motor. Further, the former 6.5% Si-Fe is generally fragile and difficult to handle and process, is not suitable for high precision machining, and is difficult to use for a motor that has a small gap and high output. The motor of the present invention is
A magnetic steel sheet with a content of 1 wt% or less other than iron, a relatively low price, a plate thickness of 0.25 mm or less, and high precision machining is used. Therefore, since the motor core can be machined with high precision, the motor gap can be narrowed and the motor output can be increased. Further, the material cost and processing cost of the core are reduced, and the motor can be made relatively inexpensive.

[Brief description of drawings]

FIG. 1 shows an induction motor type high speed motor.

[Explanation of symbols]

 1 armature core 1'teeth of the armature core 2 outermost core of the rotor 3 inner core of the rotor 4 armature winding 5 secondary conductor 6 gap between the rotor and the stator (armature)

Claims (10)

[Claims] 1. A high-frequency electromagnetic steel sheet having a plate thickness of 0.25 mm or less, a main component of iron, and a content of components other than iron of 1% by weight or less, at least one of an armature core and a field core. High-frequency motor characterized by being used for. 2. The saturation magnetization is 2.1 T or more and 100 H.
A high-frequency motor, characterized in that a high-frequency electromagnetic steel sheet having an iron loss of z, 1.5T of 4 W / kg or less is used for at least one of an armature core or a field core. 3. The high frequency motor according to claim 1, wherein an electromagnetic steel sheet having an interlayer resistance of 1 Ωcm ² / sheet or more is used for at least one of the armature core and the field core. 4. The high frequency motor according to claim 1, further comprising a core made of a non-oriented electrical steel sheet. 5. The high frequency motor according to claim 1, further comprising a core formed by rolling and stacking grain-oriented electrical steel sheets. 6. A magnetic steel sheet having a plate thickness of 0.25 mm or less, a main component of iron, and a content of a component other than iron of 1% by weight or less is provided with a gap of at least one of an armature core and a field core. A high-frequency motor characterized by being used in the vicinity. 7. The saturation magnetization is 2.1 T or more and 100 H
A high-frequency motor, characterized in that a high-frequency electromagnetic steel sheet having an iron loss of z, 1.5T of 4 W / kg or less is used near a gap of at least one of an armature core or a field core. 8. The high frequency motor according to claim 6, wherein an electromagnetic steel sheet having an interlayer resistance of 1 Ωcm ² / sheet or more is used. 9. The high frequency motor according to claim 6, further comprising a core made of a non-oriented electrical steel sheet. 10. A core formed by rolling and stacking grain-oriented electrical steel sheets.
High frequency motor.