JPH04255443A - Armature for miniature motor - Google Patents

Abstract

PURPOSE:To enhance insulation between a coil and a core by applying an insulating coating material onto a part of the side face at an arm section constituting a core and then laminating and winding a coil on the outside thereof. CONSTITUTION:A coating member 11 is applied on a part, preferably on the intermediate part, of the side face of the arm section 7 of a core 1. Widthwise dimension (w) of the coating member 11 is set two times or more of the thickness of a core 1a forming the core 1 and the thicknesswise dimension (t) is set correspondingly to the thickness dimension of an insulating board 8. When a coil 6 is lamination wound, internal inflation due to the tightening force of the winding forming the coil 6 is prevented because the coating member 11 is placed between the core 1 and the coil 6 and thereby direct contact between the core 1 and the coil 6 can be prevented. According to the invention, insulation between the coil and the core can be enhanced while sustaining the space factor of the winding.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention consists of a plurality of coils wound around an iron core and a commutator for power supply, which are rotatably interposed within a stator having a plurality of magnetic poles. The present invention relates to an armature for a small motor equipped with a coil, and particularly to an armature for a small motor that maintains the winding space of the coil and improves the insulation between the coil and the iron core.

0002

2. Description of the Related Art FIG. 3 is an end view of essential parts showing an example of an armature for a small motor, which is the object of the present invention, and FIG.
FIG. In FIGS. 3 and 5, reference numeral 1 denotes an iron core, which is formed by laminating cores 1a made of silicon steel plates or the like in the axial direction. Three armature poles 2 are provided on the outer periphery, and an armature shaft is provided at the axial center. 3 is inserted and fixed. 4 is a commutator, which is fixed to the armature shaft 3 via an insulating tube 5. A coil 6 is wound around the arm portion 7 constituting the iron core 1, and a terminal lead wire (not shown) is connected to the commutator 4.

Next, reference numeral 8 denotes an insulating plate, which is a thin plate made of an insulating material and has a U-shaped cross section in a plane parallel to the axis, and is provided on the end face of the arm portion 7 and in the vicinity thereof. The coil 6 is laminated and wound on the outside of the arm portion 7 and the insulating plate 8.

0004

[Problems to be Solved by the Invention] In the above-mentioned conventional armature for a small motor, the larger the core lamination dimension T becomes, the more the winding forming the coil 6 is bound by the lamination in the intermediate portion 7a of the arm portion 7. As a result of this action, it bulges inward and comes into contact with the arm portion 7, resulting in an electrical leakage or insulation failure, resulting in a problem in that the characteristics and reliability of the small motor are degraded.

In order to solve the above problem, it may be possible to increase the thickness of the insulating plate 8, but this would reduce the winding space of the coil 6, lowering the motor output, and increasing the thickness of the insulating plate 8. It is not necessarily recognized as an effective means for preventing the inward bulge caused by the bondage described in No. 6.

FIG. 6 is an explanatory cross-sectional view showing another example of the prior art, and corresponds to FIG. 5 described above. In FIG. 6, reference numeral 9 denotes an insulating core, which is formed of an insulating material to have a width slightly larger than the arm width w of the core 1a, and is laminated by being interposed in the middle part of the iron core 1 (for example, 39-
(See Publication No. 25487).

With the above configuration, the arm portion 7 and the coil 6
However, since the insulating core 9 is interposed within the iron core 1, the magnetic circuit is interrupted, resulting in a disadvantage that the motor performance is reduced. Furthermore, the process of laminating the iron core 1 becomes complicated, causing undesirable problems in production.

FIG. 7 is an explanatory cross-sectional view showing still another example of the prior art, and corresponds to FIGS. 5 and 6. In FIG. 7, a coating 10 is provided on the end and side surfaces of the arm portion 7 using an insulating material such as epoxy resin.

With the above configuration, the entire surface of the arm portion 7 that touches the coil 6 is insulated by the coating 10, so the insulation properties are significantly improved, but a process for applying the coating 10 is required, which increases time and man-hours. However, it has the disadvantage of high cost. Furthermore, as the outer diameter of the iron core 1 becomes smaller and the laminated length of the core 1a becomes larger, the thickness of the coating 10 becomes non-uniform and the winding space decreases.

[0010] In addition to the above methods, attempts have been made to insulate the entire iron core 1 by forming a coating such as by phosphate chemical conversion coating, but the strength of the insulating coating is not only insufficient. , there is a problem that the armature shaft 3 (not shown, see FIG. 3) and other constituent members are contaminated.

The present invention solves the problems existing in the prior art described above, and provides an armature for a small motor that maintains the winding space of the coil and improves the insulation between the coil and the iron core. The purpose is to

0012

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises a plurality of coils wound around an iron core and a commutator for power supply, and a plurality of magnetic poles are arranged. In an armature for a small motor that is rotatably installed in a stator made of an insulating material, it is made of an insulating material and has a U-shaped cross-sectional shape in a plane parallel to the axis at and near the end face of the arm part that constitutes the iron core. A covering member made of an insulating material and having a thickness corresponding to that of the insulating plate is provided on a part of the side surface of the arm portion, and the insulating plate and A technical measure was adopted in which coils were layered and wound on the outside of the covering member.

In the present invention, as the insulating material constituting the covering member, a resin material such as melamine, acrylic, epoxy, polyurethane, phenol, or polyester can be dissolved in an organic solvent and used in the form of a slurry.

[0014]

[Function] With the above structure, since the covering member is interposed between the coil and the iron core, direct contact between the two can be prevented even by the laminated binding of the windings forming the coil.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory sectional view showing an embodiment of the present invention, and corresponds to FIGS. 5 to 7, and FIG. 2 is a sectional view taken along the line B--B in FIG. 1. Note that the same parts are shown in Figures 3 and 5 above.
7 are designated by the same reference numerals as in FIG. In FIGS. 1 and 2, reference numeral 11 denotes a covering member, which is applied to a part of the side surface of the arm part 7, preferably to the middle part. Note that the covering member 11
It is preferable to select the width dimension w to be at least twice the thickness of the core 1a forming the iron core 1, and the thickness dimension t to correspond to the thickness dimension of the insulating plate 8.

With the above configuration, even when the coil 6 is laminated and wound, since the covering member 11 is interposed between the iron core 1 and the coil 6, the inward movement due to the binding force of the windings forming the coil 6 can be prevented from bulging, and direct contact between the iron core 1 and the coil 6 can be prevented.

FIG. 4 is an explanatory cross-sectional view showing another embodiment of the present invention, and the same parts are designated by the same reference numerals as in FIGS. 1 and 2. In FIG. 4, the covering member 11 is attached to two intermediate portions of the side surface of the arm portion 7, respectively. This configuration is effective in preventing contact between the iron core 1 and the coil 6 even when the lamination dimension T of the core 1a is large.

In the above embodiment, an example was described in which there were three armature poles and three coils, but the effect is the same even if there are three or more armature poles and three coils. It goes without saying that the present invention can also be applied to arm portions having a cross-sectional shape other than rectangular.

[0019]

[Effects of the Invention] Since the present invention has the structure and operation as described above, the processing work is easy, there is no contamination of other components, and the coil and core are connected while maintaining the winding space. This has the effect of improving the insulation between them.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB in FIG. 1.

FIG. 3 is an end view of essential parts showing an example of an armature for a small motor, which is a subject of the present invention.

FIG. 4 is a cross-sectional explanatory diagram showing another embodiment of the present invention.

FIG. 5 is an explanatory cross-sectional view taken along line A-A in FIG. 3;

FIG. 6 is a cross-sectional explanatory diagram showing another example of the prior art.

FIG. 7 is a cross-sectional explanatory diagram showing still another example of the prior art.

[Explanation of symbols]

1 Iron core 6 Coil 7 Arm part 8 Insulation board 11 Covering member

Claims (1)

[Claims] [Claim 1] For a small motor, which is composed of a plurality of coils wound around an iron core and a commutator for power supply, and is rotatably interposed in a stator having a plurality of magnetic poles. In the armature, an insulating plate made of an insulating material and having a U-shaped cross section in a plane parallel to the axis is provided on the end face of the arm part constituting the iron core and in the vicinity thereof. A covering member made of an insulating material and having a thickness corresponding to that of the insulating plate is attached to the part, and a coil is laminated and wound around the outer side of the insulating plate and the covering member. Armature for small motors.