JPH0583901A - Stator core of ac generator for car - Google Patents

Abstract

PURPOSE:To improve insulating properties by inserting a resin, which does not transmit vibrations due to magnetic exciting force to a frame and is deformed elastically or plastically, into a plurality of recessed sections of the outer circumferential section of a stator core. CONSTITUTION:A plurality of recessed sections 12 are formed to the outer circumferential section of a stator core laminated, and the recessed sections 12 are filled with a resin 13 up to the outer circumferential surface of the core. A molding resin is charged and cured in a mold in filling, and the thin-film sections 15 of the slot inner circunferential surfaces of inner-circumferential side slots 14 and side faces are also coated with the same resin. The resins 13 on the outer circumferential section and the resins 15 on the slot inner circumferential surface are connected partially by the resin through the recessed sections 12, thus allowing integral molding. A stator coil 2 is heat-generated by power generation, the heat is transmitted over a stator core 1, and the resins 13 charged into the recessed sections 12 are expanded in an extent larger than frames 21, 22. Accordingly, the stator core 1 fast stuck to the frames 21, 22 is brought to a state, in which the stator core is floated from the frames through the resins 13, and peak noises can be reduced by the damping effect of the resins 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator core of an alternator for vehicles such as automobiles, and more particularly to a stator core for reducing noise caused by magnetic excitation force.

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing a stator core of a generator of this type, as shown in JP-A-63-194542 and JP-A-63-265532, a powdery insulation method is used as an insulation method in the slots on the inner peripheral side of the stator core. There were many examples of using resin. However, the powdery insulating resin has a problem that pinholes are easily formed.

On the other hand, as a stator core manufacturing method for achieving low noise, Japanese Patent Laid-Open No. 61-258635 discloses that an elastic member is provided on the outer circumference of the stator core.

In general, the stator core is formed by laminating thin plates to reduce iron loss and is integrated by welding or the like. Since the lamination dimensions vary greatly, a metal member for absorbing the dimensional tolerance in the lamination direction may be required. Since the inner circumference of the stator core cannot be completely fixed in the conventional example, there is a problem that the accuracy of the air gap is poor.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention improves the insulation of the stator core and the manufacturing method of the stator core by reviewing the elastic member provided on the outer periphery of the core. It is an object of the present invention to provide a stator core manufacturing method capable of significantly reducing the level of noise due to magnetic excitation force by improving dimensional accuracy.

[0006]

In order to achieve the above object, the stator core has a plurality of recesses in its outer peripheral portion, and the recesses have an elastic effect with a damping effect to prevent the vibration due to the magnetic excitation force from being transmitted to the frame. A resin that deforms mechanically or plastically is inserted.

Further, the above member is also used as an insulating material for a plurality of slots opened to the inner peripheral side of the stator core, and is integrally molded with the above resin.

[0008]

According to the above construction, the insulation of the stator core and the damping effect of the stator can be obtained at the same time. While the inside of the slot is insulated by resin, mechanically the stator core is supported by the frame, but when the temperature of the stator core rises due to heat generation of the stator coil, the resin expands by thermal expansion and its volume increases larger than the frame. Since the stator core is not in direct contact with the frame, vibration of the stator core is less likely to be transmitted to the frame, and noise can be significantly reduced.

[0009]

Embodiments will be described in detail below with reference to embodiments shown in FIGS.

The stator core 1 is shown in FIG.
As shown in the sectional view of FIG. 3, a plurality of recesses 12 are provided on the outer peripheral portion of the laminated stator cores, and resin 13 is provided in the recesses.
Is filled up to the outer peripheral surface of the core. The filling is performed, for example, by filling and hardening a molding resin in a mold (not shown). The thin film portion 15 on the inner peripheral surface of the inner peripheral slot 14 and the side surface 1
6 and 17 are also covered with the same resin.

In recent years, a highly heat-resistant resin called spar engineering plastic has been developed, and thin-wall molding has become possible.

Further, since the resin 13 on the outer peripheral portion and the resin 15 on the inner peripheral surface of the slot are partially connected by the resin 18 via the recess 12, they can be integrally molded.

On the other hand, the stator core 1 is punched in a pressing process as shown in FIG. 5 and laminated in a spiral shape in order to improve the material yield. For this reason, there is an edge portion 19 at the bottom of the slot, and in the case of powder insulation, the insulating film thickness of this portion was a problem, but according to the present invention, a free film thickness can be secured by the mold.

Next, the mechanism of noise reduction in the structure of the present invention will be described with reference to FIG.

Stator core 1 whose slot inner circumference is insulated
The armature coil 2 is wound around and is fitted in the spigot with the frames 21 and 22.

A rotor (not shown) and a stator core 1
The inner diameter of the rotor is rotating through a very small gap (for example, about 0.5 mm), and this air gap becomes non-uniform, so that the rotor magnetic excitation force also pulsates, and When the number of rotations matches the resonance frequency, the stator core 1 resonates and propagates through the frames 21 and 22 to generate noise.

In the present invention, the stator coil 2 generates heat due to power generation, the heat is transmitted to the stator core 1, and the resin 13 filled in the recess expands more than the frames 21 and 22. The stator core 1 that has been floated from the frame via the resin 13 has a damping effect of the resin 13.
1800r / when compared with a 2V70A class generator
Peak noise (dB-A) from m to 4000r / m is about 1
It was possible to reduce by 5%.

[0018]

According to the present invention, the inner circumference of the status lot can be reliably insulated, and the side surfaces 16 and 17 of the stator core can be reliably insulated.
Since the insulating film thickness of the portion can be formed into a shape that allows the armature coil 2 to be easily inserted, the insulation failure rate during winding can be reduced.
Further, since the stator core is fitted with the spigot, the air gap nonuniformity is reduced, and while the stator core is reliably supported, the transmission to the frame is suppressed by the damping effect of the resin, and a low noise vehicle alternator can be configured.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a stator core of a vehicle AC generator according to an embodiment of the present invention.

FIG. 2 is an AA cross-sectional view of a stator core.

FIG. 3 is a BB cross-sectional view of the stator core.

FIG. 4 is a partial cross-sectional view showing a support structure of a stator core.

FIG. 5 is an explanatory diagram of a pressing process of the stator core.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stator core, 2 ... Armature winding, 12 ... Stator core outer peripheral recessed part, 14 ... Stator core slot part, 13 ... Members which are elastically or plastically deformed, 21, 22 ... Frame.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Honda, 2520 Takaba, Katsuta-shi, Ibaraki Takaba, Hitachi, Ltd. Automotive Equipment Division (72) Inventor Yoichi Nakano 2520, Takata, Katsuta, Ibaraki Hitachi, Ltd. Mfg. Co., Ltd. Automotive Equipment Division (72) Inventor Kenji Ishihara 2477 Kashima Yatsu Kashima, Katsuta City, Ibaraki Pref. 3 Hitachi Automotive Engineering Co., Ltd.

Claims (2)

[Claims] 1. A stator core for a vehicle alternator, comprising a laminated iron core, having a plurality of recesses in an outer peripheral portion of a stator core, and having a plurality of slots open to an inner peripheral side, wherein the recess has a resin. A stator core of a vehicle AC generator, wherein the inside of the slot is also covered with the resin. 2. The stator core of an automotive alternator according to claim 1, wherein the stator core is formed by resin integral molding.