JPH0393443A - Mold commutator and commutator motor - Google Patents

Abstract

PURPOSE:To improve commutation without increasing the number of commutator segment by forming groove sections in the opposite side faces of adjacent commutator segments, arranging dielectrics having electrodes in the groove sections and then arranging the electrodes of the dielectrics in the groove sections of adjacent commutator segments while press-contacting therewith. CONSTITUTION:Groove sections 3 are formed in the opposite side faces of adjacent commutator segments 1 and in the foot section 2 thereof, and then electrodes 5 arranged on the opposite side faces of a dielectric 4 having profile identical to that of the groove section 3 are placed in the groove sections 3 of adjacent commutator segment 1 while press-contacting therewith. Predetermined number of thus arranged commutator segments 1 and dielectrics 4 are integrally molded with molding material 6 thus producing a mold commutator. Since each commutator segment is short-circuited through the dielectric, commutation can be improved, the number of commutator segment can be decreased and the size of motor can be reduced. Furthermore, since the number of commutator segment can be decreased a thicker winding can be employed and thereby high output can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a molded commutator for a commutator motor used in electric tools, vacuum cleaners of home appliances, and the like.

Conventional technology Conventionally, this type of molded commutator has been used to eliminate sparks between the commutator and brushes and extend the life of the brushes. (hereinafter referred to as child pieces) in order to suppress the voltage between the child pieces. Also, in the case of low voltage of 50V or less,
A dielectric material is connected to the child piece separately from the commutator to improve rectification. In either case, the commutator itself typically does not contain a dielectric.

However, in recent years, motors have become smaller and faster,
With the increase in output power and automatic assembly, problems have arisen in the commutators, such as poor rectification that cannot be made smaller and excessive man-hours.

Hereinafter, a conventional molded commutator as described above will be explained with reference to the drawings.

Figures 3 and 4 show the configuration of a conventional molded commutator. Figure 3 is a cross-sectional view of the conventional molded commutator taken along a plane perpendicular to the rotation axis, and Figure 4 is a cross-sectional view of the conventional molded commutator taken along a plane perpendicular to the rotation axis. FIG.

First, it is a child piece made of a steel alloy, has a leg portion 2 and a tapered portion 7, and is held by a molding material 6.

This commutator has a predetermined number of child pieces 1 arranged in a ring shape and is integrally molded with a molding material 6. FIG. 5 is a diagram showing the armature configuration of a low-voltage motor, in which the dielectric 4 is inserted into the slot 9 of the armature 8 together with the armature coil 10, and the electrode 11 of the dielectric 4 is connected to the armature of the child piece 1. It is connected to the hook portion 12 together with the armature coil 10 by welding or soldering.

The molded commutator rotates while being fixed to the rotating shaft 13 of the motor armature 8, and is in sliding contact with a brush (not shown) that is in contact with it to perform a rectifying action. In order to eliminate noise, prevent noise, and improve brush life, the number of probes is increased, the voltage between the probes is reduced, and sparks are suppressed, and a dielectric material is connected between the probes to absorb the voltage between the probes and improve rectification. .

Problems to be Solved by the Invention However, in the above configuration, if the number of armature pieces is increased, the width of the armature pieces becomes narrow unless the outer diameter of the commutator is increased, and armature coils of the same wire diameter cannot be connected. The outer diameter of the commutator naturally becomes large.

In addition, in a low-voltage motor that requires a small number of pieces, the dielectric 4 can only be installed in the slot of the armature.
The number of turns and diameter of the armature coil wound in the same slot are greatly restricted, and the degree of freedom in motor design is extremely limited. In either case, there were problems that hindered miniaturization, high output, and automation.

In view of the above-mentioned problems, the present invention provides a molded commutator that can easily achieve miniaturization, high output, and automatic assembly of motors without increasing the number of commutator pieces.

Means for Solving the Problems To achieve this object, the molded commutator of the present invention comprises:
Grooves are formed on both surfaces of adjacent commutator pieces in the rotational direction, and a dielectric material having electrodes on both side surfaces whose shape matches the groove portions is disposed in the groove, and the electrodes of this dielectric material The commutator is in pressure contact with the grooves of the strips, and is configured to hold the leg portions of the commutator with a molding material.

Function: With the above configuration, the present invention can automatically connect and fix the dielectric to each commutator piece, and the action of the dielectric built into the commutator allows smooth rectification without increasing the number of pieces. It is possible to achieve smaller size.

EXAMPLE Hereinafter, a molded commutator according to an example of the present invention will be described with reference to the drawings.

1 and 2 show the structure of a molded commutator according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of the molded commutator taken along a plane perpendicular to the rotation axis, and FIG. is a sectional view taken along a plane parallel to the rotation axis.

1 is a commutator piece, the leg part 2 and the adjacent commutator piece 1
Grooves 3 are formed on both side surfaces of the dielectric 4, and electrodes 5 on both side surfaces of the dielectric 4 whose shape matches the grooves 3 are pressed into the grooves 3 of the adjacent commutator pieces 1. A predetermined number of commutator pieces 1 and dielectric material 4 thus arranged are integrally molded with a molding material 6 to obtain a molded commutator.

As described above, in this embodiment, grooves are formed on both sides of the adjacent commutator pieces, a dielectric whose shape matches the grooves is arranged in the bottom part, and the dielectric electrodes are connected to the sides of the adjacent commutator pieces. To provide a small molded commutator having a dielectric material which suppresses sparks and significantly improves rectification by being placed in pressure contact with a groove part.

In this example, the dielectric is round, but it goes without saying that there is no problem whether the dielectric is rectangular or square as long as it matches the shape formed by the grooves between the commutator pieces. stomach.

Effects of the Invention As described above, the present invention forms grooves on both side surfaces of adjacent rectifying strips in the direction of rotation, and arranges in the grooves a dielectric material having electrodes on both sides whose shape matches the grooves. The dielectric electrodes are pressed into the grooves of adjacent commutator pieces and held by a molding material, and each piece is short-circuited with the dielectric, which dramatically improves rectification. This makes it possible to reduce the size of the motor. Furthermore, by reducing the number of commutator pieces, thicker windings can be connected and higher output can be achieved. In addition, it goes without saying that miniaturization of the commutator enables higher speeds, and when the dielectric is made of ceramic material, the mechanical strength of the commutator is further improved as the dielectric acts as a reinforcing material, resulting in even higher speeds. enable.

Furthermore, there is no need to separately connect the dielectric to the commutator bars, making it easy to automate winding connections.

As described above, the molded commutator of the present invention has a simple structure and produces great practical effects.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the molded commutator of the present invention taken along a plane perpendicular to the rotational axis, Figure 2 is a cross-sectional view taken along a plane parallel to the rotational axis, and Figure 3 is a cross-sectional view of a conventional molded commutator. FIG. 4 is a sectional view taken along a plane perpendicular to the rotation axis, FIG. 4 is a sectional view taken along a plane parallel to the rotation axis, and FIG. 5 is an armature configuration diagram of a conventional low voltage motor. 1... Commutator piece, 3... Groove, 4...
...dielectric, 5...electrode, 6...
mold material. Figure 2 Figure 3 Figure 4 Figure 5 Figure 13

Claims (1)

[Claims] (1) Grooves are formed on both side surfaces in the rotational direction of adjacent commutator pieces, and a dielectric material having electrodes on both side surfaces whose shape matches the groove portions is disposed in the groove portions, and the electrodes of this dielectric material are arranged in the groove portions. A molded commutator that is in pressure contact with the grooves of adjacent commutator pieces and holds the legs of the commutator pieces with a molding material. 2. The molded commutator according to claim 1, wherein the dielectric is made of a ceramic material. 3. A commutator motor using the molded commutator according to claim 1 or 2.