JPH0631348U - Motor core structure - Google Patents

Abstract

(57) [Abstract] [Purpose] In a thin DC motor, etc., the insulating layer formed between the core and the coil is thinned while ensuring its insulating property, and the coil is wound with a large tension to thin the coil layer. In addition to being able to be configured, the motor will be made thinner. [Structure] A core formed by stacking a plurality of laminated single plates 32
In 29, each laminated veneer 32 is laminated so that the side of the surface where the sag 1 is generated by punching and the side of the surface where the burrs 2 are formed face each other, and is laminated on the outermost side, and the surface where the side where the burrs 2 is generated is the surface. The corners 3 (burrs) of the plate 32a are chamfered to remove the burrs 2. [Effect] The insulating layer 33 can be configured to have the same thickness as that of the flat surface portion, and when the coil 28 is wound, the insulating property at the corner portion 3 is guaranteed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a motor core structure, and is particularly applied to a thin motor core applied to a VTR, a disk device, or the like, and it is possible to reduce the overall thickness of the motor while ensuring a complete insulating layer between the coil and the core. For improvement to realize.

[0002]

[Prior art]

 Brushless DC motors are often used as motors built into electronic devices such as VTRs and disk devices, but in order to reduce the size of the entire device, it is an important issue to make DC motors thinner. ing. There are various types of DC motors, but VTRs and the like often use a motor having a structure as shown in FIG.

The DC motor shown in the figure is a type of motor that is directly attached to a substrate and has a structure of an outer rotor circumferentially opposed type. Here, the rotor 21 side has a structure in which a rotor magnet 24 is attached inside a shallow cap-shaped rotor yoke 23 fixed to a spindle shaft 22. On the other hand, on the stator 25 side, a core 29, around which a coil 28 is wound, is fixed with screws 30 to a stator frame 27 fixed to a substrate 26, and the outer peripheral surface of the core 29 faces the rotor magnet 24 on the rotor 21 side. The stator frame 27 pivotally supports the spindle shaft 22 via the radial bear ring 31.

Further, the core 29 on the stator 25 side is a slot type, and as shown in FIG. 3, it has a planar shape in which a plurality of magnetic poles (12 poles in the figure) are radially formed, and a thin soft iron plate or silicon steel plate. It has a laminated structure in which a plurality of laminated single plates 32 (see FIG. 2) obtained by punching the above into a plane shape are laminated. A coil 28 is wound around each magnetic pole of the core 29 by a winding method corresponding to the number of phases, and the rotor 21 side is rotated by energizing the coil 28 of each phase at a predetermined timing.

[0005]

[Problems to be solved by the device]

 By the way, in order to prevent the current flowing through the coil 28 from leaking to the core 29, it is necessary to form an insulating layer 33 between the coil 28 and the core 29. Generally, the surface of the core 29 is coated with insulating paint. Or a means for covering with a resin mold is adopted.

In a thin motor, the insulating layer 33 is configured to have a thickness of about 0.3 mm. However, the demand for thinner motors is not limited to the thickness of the insulating layer 33, and the insulating property is ensured. It is becoming an important technical issue how much the thickness can be reduced while maintaining the above.

More specifically, when the insulating layer 33 is formed by applying an insulating coating material, the insulating layer 33 becomes thin at the corners of the core 29, so that the thickness is limited to about 0.2 mm. It is being touched. This is because the burrs and sags peculiar to the punching process occur in the corners of the laminated veneer that is formed in the punching process by the press machine, and in particular, the burrs side has sharp protrusions. This is because when the insulating coating is applied to the, the insulating layer becomes extremely thin due to the influence of the surface tension of the coating. That is, as shown in FIG. 4 (a cross-sectional view taken along the line XX in FIG. 3 and an enlarged view of a main portion thereof), a burring portion 40 is generated in the outermost laminated single plates 32a and 32b. In the laminated veneer 32a on the other side, the insulating layer 33 becomes extremely thin at the burring portion 40, and for example, when the flat portion has a thickness of 0.1 mm, the burring portion 40 has a thickness of about 0.04 to 0.05 mm. In many cases, the insulating layer 33 is damaged in the winding process of the coil 28 and the current of the coil 28 leaks to the core 29.

Further, not only when the insulating coating is applied, but also when the insulating coating is made by the mold resin, if the insulating layer 33 is thin in the burrs portion 40, sufficient tension is applied to the coil 28. Therefore, the coil 28 cannot be wound tightly, and as a result, the thickness of the layer of the coil 28 becomes large, which prevents the motor from being made thinner.

In view of the above, according to the present invention, even if the insulating layer is thinned, the thickness of the layer does not become extremely thin in the burring part of the laminated single plate, and the motor is designed while completely insulating between the coil and the core. It was created for the purpose of providing a core structure that can be made even thinner.

[0010]

[Means for Solving the Problems]

 According to the present invention, a plurality of laminated veneers are machined in a motor core constituted by laminating a plurality of laminated veneers by punching a ferromagnetic thin plate work by punching. At the same time, the laminated veneer is laminated so that the sagging surface side and the burring surface side face each other, and at least the laminated veneer with the burring surface side of the outermost laminated veneer is the coil. The core structure of the motor is characterized in that the burrs are removed in the parts.

[0011]

[Action]

 The core is constructed by laminating a plurality of laminated veneers, but since the sagging surface side and the burring surface side face each other, the laminated veneers are in close contact, and the laminated core as a whole is laminated. The thickness can be reduced.

In the laminated state, one of the outermost laminated veneers has its burring surface side as the surface, but in the present invention, the burring part of the laminated veneer is removed. Therefore, when the insulating paint is applied, it is possible to prevent the insulating layer at the corners from being thinned due to the influence of the surface tension, and the thickness of the insulating layer can be made uniform. Also, if the sharp edges remain, the insulating layer made of insulating paint or molding resin is easily damaged during the coil winding process, etc., but this invention eliminates the edges. The damage can be prevented, and it becomes possible to wind the coil wire while applying a larger tension. Therefore, even if the insulating layer is made thin, the core and the coil are not short-circuited, and the coil layer can be made thin.

It should be noted that the burrs may be removed only on the wound portion of the coil for the purpose of preventing a short circuit between the core and the coil, but may be removed on the entire corners of the laminated single plate.

[0014]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. Similar to FIG. 4, FIG. 1 shows a cross-sectional view of the wound portion of the coil 28 in the core 29 and an enlarged view of the main part thereof, and in FIG. 1, the portions designated by the same reference numerals as those in FIGS. Corresponding elements and parts identical to those shown in these figures.

The structure of the core 29 in the present embodiment is characterized in that the laminated single plates 32 are first laminated so that the sagging generation surface side and the burring generation surface side during processing thereof face each other. That is, each laminated single plate 32 is formed into a predetermined shape (planar shape in FIG. 3) by punching from a work of a thin soft iron plate or a silicon steel plate which is a ferromagnetic material, but the punching process involves shearing. Even if the clearance between the upper and lower molds is set delicately, sagging 1 and burrs 2 occur at the corners of the laminated single plate 32 after punching. In this embodiment, as shown in FIG. 1, since the lapping 1 generation surface side and the burring 2 generation surface side of each laminated veneer 29 are laminated so as to face each other, the burring 2 covers the outer surface of the sagging 1. As a result, the flat portions of the laminated single plates 32 are laminated in close contact with each other.

By the way, according to the above-mentioned lamination method, in the core 29 in this embodiment, one laminated single plate 32a laminated on the outermost side has the surface on which the burrs 2 are generated as the surface, and the other laminated single plate 32a. In 32b, the side where the sagging 1 occurs is the surface, and the portions where the burr 2 and the sagging 1 occur form the corners of the core 29, respectively. Then, an insulating paint is applied to the coil-wound portion of the core 29 to form a film of the insulating layer 33. In that case, since the corner portion where the sagging 1 occurs is a curved surface, the insulating layer 33 has the same thickness as the flat portion, but if the corner portion 3 where the burr 2 occurs is left as it is. Since the burrs 2 are sharply projected, the surface tension of the insulating paint makes the coating layer very thin. For example, if the flat part is applied to a thickness of 0.1 mm, the area of the burrs 2 will be about 0.04 to 0.05 mm, and when the coil 28 is wound, the insulation between the coil 28 and the core 29 cannot be guaranteed. .

Therefore, in the present embodiment, as shown in the right diagram of FIG. 1 (enlarged view of the main part), the thickness of the laminated veneer 29a whose surface on which the burrs 2 are generated is 0.05 mm with respect to the corners 3 thereof. The burrs 2 are removed by performing the above chamfering process. As a result, even in the corner portion 3, the insulating paint coating layer is formed to have the same thickness as that of the flat surface portion, so that even if the thickness of the insulating layer 33 in the flat surface portion is reduced to about 0.1 mm, Insulation can be sufficiently guaranteed, and it is possible to reduce the thickness of the core 29 by 0.4 mm compared to the case where the thickness of the insulating layer 33 had to be about 0.3 mm as in the past. become.

Further, since the insulating layer 33 at the corner portion 3 is thick as described above, it becomes possible to apply sufficient tension to the coil wire when the coil 28 is wound, The layer of the coil 28 can be thinned accordingly. The same applies to the winding condition of the coil 28 even when the insulating layer 33 is formed by covering the mold resin film. The insulating layer 33 is not destroyed even when the coil is strongly wound, and the insulation between the coil 28 and the core 29 is guaranteed.

In other words, in the core structure of the present embodiment, the insulating layer 33 and the coil layer can be thinly formed, and in combination with the laminating method of the laminated single plates 29 described above, the motor can be made thinner accordingly. it can. Actually, when the thickness of the motor shown in FIG. 2 is 4.6 mm, it can be reduced to 4.2 mm or less when the core structure of this embodiment is applied, and the motor can be assembled with a high packing density. For electronic devices such as VTRs, the reduction in thickness by 0.4 mm is extremely significant.

As a means for chamfering the burrs of the laminated veneer 32a, a method of chamfering by pressing, a machining method such as electric discharge machining or barrel machining can be adopted. In particular, when chamfering by press working, a progressive method using the same die can be adopted in the punching process of the laminated veneer 32, so that the same manufacturing process as before can be performed without increasing the number of processing steps. It can be manufactured at a cost.

Further, it is not necessary to perform the above-mentioned chamfering process on the corner portions 3 of the entire circumference of the laminated single plate 32a, and it is sufficient to perform the chamfering process only on the winding portion of the coil 28. On the other hand, in the present embodiment, the corner portion on the laminated single plate 32b side is not chamfered because it is a curved surface with sagging 1. However, if necessary, the corner portion is also chamfered. Good.

[0022]

[Effect of device]

 The motor core structure of the present invention has the following effects due to the above configuration. In a motor core configured by punching a laminated veneer from a ferromagnetic thin plate work and laminating a plurality of the laminated veneers, the sagging surface side and the burring surface side of each laminated veneer are made to face each other. In addition, by removing the burrs that become the corners of the core in the laminated state, the laminated thickness is made thinner and the insulating layer is made thinner while ensuring the insulation at the corners when the coil is wound. It is possible to configure the motor and realize a thinner motor. In addition, the coil layer can be made thin because the insulation at the corners of the core is not lost even when a large amount of tension is applied to the coil wire, and this also contributes significantly to making the motor thinner.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a core (in a coil winding state) and an enlarged view of essential parts according to an embodiment to which a motor core structure of the present invention is applied.

FIG. 2 is a cross-sectional view of a thin motor.

FIG. 3 is a plan view of a slot type core (in a coil winding state).

FIG. 4 is a cross-sectional view of a core (a coil winding state) and an enlarged view of a main part thereof in a conventional technique.

[Explanation of symbols]

1 ... Sagging, 2 ... Burr, 3 ... Corner, 21 ... Rotor, 22 ... Spindle shaft, 23 ... Rotor yoke, 24 ... Rotor magnet, 25 ... Stator, 26 ... Board, 27 ... Stator frame, 28 ... Coil, 29 ... Core, 30 ... Screw, 31 ... Radial bearing, 32, 32a, 32b ... Laminated veneer, 33 ... Insulating layer, 40 ... Burr part.

Claims (1)

[Scope of utility model registration request] 1. A core of a motor constituted by laminating a plurality of laminated veneers by punching a ferromagnetic thin plate work by punching to form a plurality of the laminated veneers. The laminating veneer surface and the burring surface side during processing are laminated so that they face each other, and at least the laminated veneer of the outermost laminated veneer with the burring surface side as the surface is at least the coil winding. The core structure of the motor is characterized in that the burrs are removed from the parts.