JPH0334295B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a molded motor in which a split core is subjected to toroidal winding and then its outer periphery is molded with molded resin.

Conventional configuration and its problems By applying toroidal winding to the continuation portion of each slot of the annular core, the coil end dimensions can be shortened and a thin motor can be obtained. However, winding the annular core requires the use of a toroidal winding machine, which is not suitable for mass production and is therefore not a preferred method.
Therefore, a method suitable for mass production would be to divide the annular core in the radial direction, wind it with a flyer-type high-speed winding machine in the yoke of each slot of the divided core, and then join the divided cores together. It is valid. On the other hand, when winding is applied to the core yoke, the winding is attached to the outer periphery of the core, making it difficult to attach a frame and assemble the motor as in the past. A method is used in which the frame is integrally formed by molding the frame with a molded resin while enclosing the winding wire.

FIG. 1 shows a sectional view of a conventional molded motor in which a split core is wound and then molded.

In the figure, reference numeral 1 indicates a split core in which only the split surfaces 1a are butted together, 2 is a winding wound around a yoke for each slot of the split core 1, and 3 is a housing made of molded resin.

In the above configuration, in order to reduce the outer diameter of the motor (outer diameter of the housing), the smaller the resin thickness _t1 covering the winding 2 is, the better; There is a paradox that the larger the number ₂ , the better. If t ₂ is large enough, there is a risk of cracking due to heat shock after molding.

On the other hand, as a method to obtain the joint strength of the iron core without using resin, it is possible to provide a concavo-convex portion 1b on the dividing surface 1a of the iron core and engage it as shown in Fig. 2, but in the case of a small iron core such as a small motor, This is a method that cannot be adopted in reality. Another method is to provide a protrusion 1c on the core dividing surface and weld the tip of the protrusion 1c as shown in Figure 3, but in this case welding is done after the winding is completed, so that the winding is not damaged during welding. , it is necessary to set the height h of the protrusion to be larger than the thickness _t3 of the winding 2. Therefore, the thickness _t4 of the molding resin at that portion becomes smaller, and there is a risk that cracks may occur in this portion due to heat shock after molding is completed. Furthermore, it is conceivable that the flow of resin is obstructed in this part during molding, and unnecessary resin molding pressure is applied to the winding part, leading to a decrease in quality.

OBJECTS OF THE INVENTION The present invention aims to solve the above-mentioned problems of the prior art and improve the strength of a molded motor in which a split core with windings is molded.

Structure of the Invention The present invention attempts to secure the resin wall thickness around the split surface joint by arranging the split surface joint of the iron core to match a protrusion such as a motor mounting foot provided on the outer periphery of the housing during molding. It is something.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 shows a case in which the present invention is applied to the core structure shown in FIG. 1, and FIG. 5 shows a case in which it is applied to the core structure shown in FIG. 3. As shown in the figure, a protruding part 4 such as a mounting foot or a flange is integrally formed on the outer periphery of a housing 3 made of molded resin, and the split surface joint part is arranged so as to be located on this protruding part 4. .

Effects of the Invention As is clear from the above configuration, according to the present invention, the following effects can be obtained.

Even in molds where the core split surfaces are simply butted together without being joined by welding, dovetails, etc., the thickness of the mold is sufficient to reinforce the split surface joints, and the protrusion for mounting the motor can be used. A motor that is easy to manufacture and inexpensive can be obtained.

For those with protrusions in the outer circumferential direction on the core dividing surface, it is possible to prevent the resin thickness from decreasing due to the protrusions, and to ensure a sufficient flow path for the resin. Molded products with stable quality can be obtained without applying excessive molding pressure.

[Brief explanation of drawings]

1 to 3 are cross-sectional views of a stator of a conventional molded motor with toroidal windings, FIG. 4 is a cross-sectional view of a stator of a molded motor according to an embodiment of the present invention, and FIG. 5 is a cross-sectional view of a stator of a molded motor according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of another embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Split iron core, 1a... Split surface, 2... Winding wire, 3... Housing, 4... Projection part.

Claims (1)

[Claims] 1 A toroidal winding is applied to the yoke of each slot of the divided iron core, which is divided into a plurality of annular iron cores having slots, and the divided surfaces are brought into close contact with each other to restore the annular shape, which is then integrally molded with mold resin. , and the joint surface is arranged at a position of a protrusion for attaching the motor that is integrally formed on the outer periphery of a housing made of molded resin.