JPH01138937A - Manufacture of induction motor stator - Google Patents

Abstract

PURPOSE:To facilitate a winding work of a toroidal winding by resin mold forming from the outside of a stator core at the time of constituting said stator core by joining of split cores. CONSTITUTION:A toroidal winding 15, which winds a yoke part 41 via an insulating means, is applied to every slot 12 of each divisionally formed split core 11. Then, respective split cores 11, to which said winding 15 has been applied, are butt-joined into an annular stator core 10 by welding in the butt part outer periphery side of split end faces 11a, 11b. After that, a molded material 18 composed of synthetic resin material is injected to the outside of said stator core 10 to cover said outside in the manner of embedding said winding 15 while leaving the tooth part 13 inner peripheral end face of the stator core 10 forming an opposed face at least to a rotor so that the whole stator core is molded into an integral body. In this manner, it is possible to obtain a stator having the reduced whole thickness including a winding.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a stator for a thin induction motor.

Conventionally, the windings that create the rotating magnetic field of the stator in induction motors are usually housed across two slots formed on the side of the stator core that faces the rotor, and the windings are inserted between the slots and the slots. The so-called coil end portions, which are the transition portions, protrude from both side surfaces of the stator core, and in addition to the dimensions of the coil end portions, the overall width in the axial direction is quite large.

In recent years, as electric motors have become smaller and lighter, there has been a growing demand for thinner motors, and various proposals have been made to meet this demand for induction motors having a large number of slots in the stator core. For example, ■ a method to increase the diameter of the stator core to thin the lamination thickness and reduce the axial width, or ■ a method to reshape the coil end portion that protrudes from the stator core, and ■ a method to reduce the windings to the stator core. axial gap using a stator placed in a radial slot of
Methods etc. are known. However, in method (2), the outer diameter of the motor becomes large, and in method (2) it takes a lot of effort to shape the coil ends. Each had their own problems, such as being unsuitable for

Therefore, as a method for reducing the thickness of an induction motor that has a large number of slots in the stator core, it is possible to reduce the thickness of the entire stator by applying a toroidal winding to each slot of the stator core. It is proposed to significantly reduce the thickness.

In implementing an induction motor with the above structure, it is important to be able to easily and efficiently manufacture a stator with toroidal windings. Manufacturing by winding the stator core requires winding it on a small bobbin, and it also requires winding in each relatively narrow slot, which makes the device complicated and does not allow for high speed. There is a problem.

Therefore, in order to facilitate the manufacture of the stator, the stator core is formed in segments, and after winding the yoke part in each slot of the split core, each It was decided to join and fix the core in an annular shape, but when the split cores are joined in this way, the magnetic flux becomes uneven and electromagnetic vibration is likely to occur in the core. Even if parts are joined by welding on the outer circumferential side, slight vibrations will occur. For example, if this is used as a drive motor for a fan, the vibrations of the motor will be transmitted from the fan to the space, causing noise. The problem arises.

Furthermore, when a toroidal winding is applied to the yoke portion of the stator core, it is also necessary to prevent the magnetic flux of the magnetic field generated by energization of the winding from flowing outward and leaking.

In view of this, in the present invention, in order to facilitate the winding work of the toroidal winding, when the stator core is constructed by joining split cores, by resin molding from the outside of the stator core. , the electromagnetic vibration of the stator core is reduced, and the implementation is completely possible.

That is, the method for manufacturing the stator of an induction motor according to the present invention is as follows:
A stator core having a large number of slots formed by teeth on the inner periphery of the yoke is divided into a plurality of parts, and each slot of the divided core is provided with a toroidal winding around which the yoke is wound. After the split cores are bonded together, the stator core is integrated by resin molding so as to embed the windings, leaving at least the inner circumferential end surface of the tooth portion that faces the rotor. shall be.

Next, embodiments of the present invention will be described based on FIGS. 1 to 7.

FIG. 1 shows a stator (1) manufactured according to the invention,
FIG. 7 schematically shows an induction motor using a stator (1) manufactured according to the present invention.

In manufacturing the stator (1), first, a tooth portion (13) and a yoke portion ( 14
) is formed by dividing into a plurality of parts in the circumferential direction, for example, into two parts at the center of the tooth part (13), as shown in the figure. The laminated plates constituting the divided cores (11) (11) are insulated and joined by adhesive or other means in the same way as conventional stator cores, and
) (11) The split end surface (lla) (
llb) cannot be insulated.

Next, as shown in FIG. 2, the yoke (14) is wound around each slot (12) of each divided core (11) (11) through an insulating means. Winding wire (15) is applied. In this case, as shown in the figure, by directly pulling out the wire such as copper wire from the winding bobbin (16) and winding it around the yoke part (14) of each slot (12),
Winding ([5)] can be easily applied.

Further, as the insulation means (17) between the winding (15) and each divided core (11) (11), the divided core (11) (
11) At least the portion where the winding wire (15) is applied is formed by coating an insulating material, or the split core shape of the tooth portion (13) and the yoke portion (14) is formed using an insulating material such as synthetic resin. Split-shaped insulating fittings (17a) and (17b) having shapes as shown in FIGS. )
(17b) has a collar (17c) that improves the winding condition.
) can be provided, and furthermore, a conductive member for the lead wire can be provided on the collar (17c).

According to the toroidal winding wire (15), the winding wire (15) itself becomes denser toward the inner center due to the pressure of the winding and becomes the minimum dimension, and the winding wire (15) also becomes loose. There will be no flying objects, and problems such as washing away or exposure to the surface will not occur during resin molding, which will be described later, and resin molding can be easily and reliably performed. Furthermore, the yoke part (14
) and the winding (15), the insulating member is interposed between the yoke (1) and the winding (15).
4) It is also less likely that a gap will be created between the core and the core due to strong pressure.

Next, each divided core (1
1) (11) is divided into split end faces (lla) (as shown in Fig. 3).
They are butt-joined by welding on the outer periphery side of the abutting portions of (llb) or by fitting the unevenness formed on the split end faces (lla) and (llb) to form an annular stator core (lO).

After joining the split cores (11) (11), the inner peripheral end surface of the toothed portion (13) forming at least the surface facing the rotor (2) of the stator core (10) is molded using a well-known resin molding method. A molding material (18) made of a synthetic resin material is injected to the outside so as to embed the winding wire (15), and the whole is integrally molded. That is, as shown in FIG. 4, the stator core (l
O) is set in the mold (20), and the mold material (18) is press-fitted into the mold (20).
Cover the outside and mold and fix. The frame portion of the electric motor is also integrally formed with this resin mold.

As this resin molding method, for example, JP-A-52-98
As can be seen in JP-A No. 909 and JP-A-53-107605, well-known molding methods such as injection molding may be used, and molding materials (18
), synthetic resin materials commonly used in this type of synthetic resin electric motors, such as synthetic resin materials made by mixing polyester-based or epoxy-based thermosetting resins with glass fibers, inorganic fillers, etc., are used. . Note that the injection pressure of the molding material (18) varies depending on the viscosity of the molding material, etc., but is usually set to about 10 kg/cd.

In the resin mold, the synthetic resin material (
18) is injected under considerable pressure, while the winding (15) is injected into the yoke (
14) in a toroidal shape, it is held tightly and tightly wound around the stator core (lO), and the molding material (18) is a relatively high viscosity resin material. Even if the mold material (18) is washed away or scratched, no defects occur. In addition, the aforementioned split core (1
1) Even if the joints between (11) are only temporary, they are firmly joined and fixed by the molding material (18) that is encased on the outside, and the whole is reliably fixed and integrated. As a result, the stator (1) has a winding (15) for each slot (12) as shown in FIGS.
) can be obtained without any problem.

The stator (1) manufactured as described above is used in an induction motor as illustrated in Fig. 7, and the stator (3) in the same figure is
(3) is a bearing that supports the shaft (4) of the rotor (2);
5) shows a frame portion made of molding material.

As described above, according to the method of the present invention, after joining the split cores each having a toroidal winding around which a yoke is wound in each slot, at least the tooth portion forming the surface facing the rotor is Since the resin molding is done from the outside so that the windings are embedded leaving the circumferential end surface and fixed, the split core can be securely fixed and held in a state where the split end faces are butt-joined together. Despite this, it is possible to reduce the electromagnetic vibration of the stator core due to uneven magnetic flux, that is, the vibration of the motor.

Therefore, according to the present invention, it is possible to divide the stator core into a plurality of parts as described above and apply a toroidal winding to each slot of the divided core without any problem. Despite this, the winding work can be streamlined, and the manufacturing efficiency of the stator with toroidal winding can be improved. In other words, since the stator core is formed in segments, the windings can be tightly wound directly onto the yoke, that is, densely and at high speed, which makes resin molding easier. It is possible to shorten the manufacturing time.

Furthermore, the resin of the molding material can protect the windings wound around the outside of the stator core, and the dimensions occupied by the resin can also prevent magnetic flux from leaking outward. Moreover, because the winding wire is tightly wound inward to the yoke part due to the winding pressure, there are few voids, and even if the resin receives a mechanical impact from the outside, the resin will remain intact. The impact is dispersed towards the inner center without being subjected to external force, resulting in a durable frame.

As described above, according to the present invention, it is possible to reduce the core vibration caused by dividing the stator core, thereby making it possible to divide the stator core, and to create a toroidal winding in each slot of the stator core. By doing so, it is possible to easily and inexpensively obtain a stator whose overall thickness including the windings is significantly reduced.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a stator manufactured according to the present invention, Fig. 2 is a schematic front view showing a state in which winding is applied to the split core, and Fig. 3 is a schematic front view showing the winding structure of the stator. 4 is a vertical sectional view showing the molded state, FIG. 5 is a partially cutaway perspective view of the manufactured stator, and FIGS. 6 [a] and (b) are parts illustrating the insulating fitting. FIG. 7 is a vertical sectional view showing an induction motor using a stator according to the present invention. (1)...Stator, (2)...Rotor, (lO)・
... Stator core, (11) (11) ... Split core, (
12) Slot, (13) Teeth, (14)
... Yoke part, (15) ... Winding wire, (18) ... Mold material, (20) ... Mold mold. Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. A toroidal winding in which a stator core having a large number of slots formed by teeth on the inner periphery of the yoke is divided into a plurality of parts, and a yoke is wound around each slot of the divided core. After the split cores are joined together, the stator core is integrated by resin molding so as to embed the windings, leaving at least the inner circumferential end surface of the teeth facing the rotor. A method for producing a stator for an induction motor.