JP2006271103A - Small motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable and inexpensive small commutator motor in which connection between commutator segments can be sustained by a ring varistor even when the armature is rotating at high speed or generating heat without increasing the overall dimensions of the motor by incorporating the motor in the commutator. <P>SOLUTION: The commutator motor is molded of synthetic resin integrally with a ring varistor 13 in a groove made by a plurality of commutator segment anchor portions 12b. Anchor portion bottom 12a of an adjacent commutator segment 12 is formed in R-shape and the ring varistor 13 touching between slits is formed in R-shape. R-shape of the ring varistor is larger than the R-shape of the anchor portion bottom of the adjacent commutator segment. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a commutator motor used for electrical equipment or home appliances, and more particularly to a commutator motor that suppresses the occurrence of sparks between commutator segments (commutator segments).

  In recent years, commutator motors used in electrical equipment or household appliances have significantly generated sparks between the brush and the commutator segment (commutator segment) as the speed, size and weight of the commutator motor increase. At the same time, there is a demand for higher reliability while further increasing the life of the brush.

In order to suppress the occurrence of sparks in such a commutator piece, it is effective to have a structure in which each commutator piece is electrically connected by a resistor element, a varistor element, or a capacitor element. As a structure, a ring-shaped varistor with a resistance film provided between the commutator and the iron core is mounted on the shaft, and each commutator piece and the ring-shaped varistor are electrically connected with an adhesive. Suppression of spark generation between the brush and the commutator piece is achieved. (For example, see Patent Document 1)
JP 2004-135368 A

  However, in the structure of the above structure, since the commutator pieces are electrically connected by attaching a ring-shaped varistor provided with a resistance film attached to the rotating shaft, the armature rotates at high speed. In some cases, the ring may be broken or scattered due to a large centrifugal force.

Further, the ring is further accelerated in breakage / scattering due to the heat generated by the motor.
Therefore, when the armature is rotated at high speed and when heat is generated, there is a problem that it is not possible to secure connection between each commutator piece by a resistance element or the like.

In addition, since a varistor is installed between the commutator and the iron core, it is necessary to provide a resistance film on the varistor. In addition, it takes a lot of man-hours to make the armature, which greatly increases the cost of the motor. There was a problem that the physique would grow.
An object of the present invention is to obtain high reliability as a motor used for such applications, or to be small and low cost.

  The commutator motor according to the present invention is formed integrally with a ring-shaped varistor and a synthetic resin in a groove formed by a plurality of commutator piece anchor portions.

  In addition, the shape of the ring-shaped varistor in which the anchor portion bottoms of the adjacent commutator pieces are in an R shape and contact between the slits is formed in an R shape, and the anchor portion bottoms of the adjacent commutator pieces are in the shape of the R The shape of the ring-shaped varistor is larger when the R shape is larger.

  According to the commutator motor of the present invention, there is provided a commutator motor that can maintain a connection between each commutator piece with a ring-shaped varistor even when the armature rotates at high speed and generates heat.

  In addition, the present invention provides a commutator motor that is highly reliable, small in size and low in cost without increasing the size of the motor by being incorporated in the commutator.

  According to a first aspect of the present invention, there is provided a substantially arc-shaped iron core having a plurality of slots, a winding wound and housed in the slot, and an output shaft fixed by penetrating the center of the iron core in the axial direction. A rotor composed of a commutator electrically connected to the ends of the windings fixed to the output shaft, and a plurality of inner peripheral surfaces having a bottomed hollow cylindrical shape that rotatably accommodates the rotor In a commutator motor comprising a case (yoke) fixed with a permanent magnet and a plurality of brushes in contact with the surface of the commutator, a ring-shaped groove is formed by the plurality of commutator piece anchor portions. This commutator motor is characterized in that it is molded integrally with a varistor and a synthetic resin, and the ring-shaped varistor is damaged or scattered even when a large centrifugal force is applied during high-speed rotation of the armature or heat generation. To prevent Rukoto can.

  Moreover, since the ring-shaped varistor is built in the commutator, the number of parts can be reduced, and the number of work steps can be greatly reduced in making an armature.

  In addition, the cost of the motor can be greatly reduced.

  In addition, the motor size can be greatly reduced.

  According to a second aspect of the present invention, the position of the commutator motor according to the first aspect of the present invention is such that the ring-shaped varistor is connected to a groove formed by an anchor portion of each commutator piece and the position is fixed. By connecting the anchor portion of each commutator piece and the ring-shaped varistor, the commutator piece is held not only by the synthetic resin but also by the ring-shaped varistor. The strength of the commutator element against centrifugal force is greatly increased, and the ring-shaped varistor is prevented from being damaged or scattered even when a large centrifugal force is applied during high-speed rotation of the armature. Can do.

  The invention according to claim 3 is characterized in that the shape of the ring-shaped varistor in which the anchor portion bottoms of the adjacent commutator pieces are R-shaped and contact each other between the slits is formed in an R-shape. The commutator motor of the commutator piece and the ring-shaped varistor are securely in contact with each other so that electrical connection is possible and a highly reliable commutating motor that absorbs sparks is provided. can get.

  According to a fourth aspect of the present invention, in the commutator according to the second aspect, the shape of the ring-shaped varistor is larger in the shape of the ring-shaped varistor than in the shape of the anchor of the adjacent commutator piece. The commutator motor is characterized in that the anchor portion bottom of the commutator piece and the ring-shaped varistor are in reliable contact, thereby enabling electrical connection and high reliability of absorbing sparks. The motor is obtained by rectification.

  A fifth aspect of the present invention is a commutator motor using the small motor according to any one of the first to fourth aspects. When the armature rotates at a high speed, a large centrifugal force is generated. It is possible to prevent the ring-shaped varistor from being damaged or scattered even when a force is applied.

Moreover, since the ring-shaped varistor is built in the commutator, the number of parts can be reduced, and the number of work steps can be greatly reduced in making an armature.
In addition, the cost of the motor can be greatly reduced.

  In addition, the motor size can be greatly reduced.

  Even when the motor generates heat or the ring-shaped varistor generates heat, the ring-shaped varistor is made of synthetic resin, so that the heat dissipation of the varistor itself is improved and the reliability can be improved.

Embodiments of the present invention will be described below with reference to the drawings 1 to 4.
FIG. 4 shows a cross-sectional view of the motor structure of the present invention.

  The rotor 8 of the motor 1 includes a substantially arc-shaped iron core 4 having a plurality of slots, a winding 2 wound and housed in the slot, an output shaft 3 that is fixed through the center of the iron core 4 in the axial direction, An end portion of the winding 2 fixed to the output shaft 3 is composed of a commutator 7 electrically connected. The rotor 8 is covered with a yoke 9 having a bottomed hollow cylindrical shape that accommodates the rotor 8 in a freely rotatable manner, and a plurality of permanent magnets 10 fixed to the inner peripheral surface. The motor 1 having such a configuration slides on the commutator 7 by the brush 5.

1 to 3 show sectional views of the commutator structure of the present invention.
FIG. 1 is a longitudinal sectional view showing the structure of the commutator 7 of the present embodiment, and FIG. 2 is a transverse sectional view showing the structure of the commutator 7, and shows a section taken along the line XX in FIG. FIG. 3 shows a cross-sectional view of the YY portion in FIG. As shown in FIGS. 1 and 3, the commutator 7 of the present embodiment is formed by arranging a large number of commutator pieces 12 on the circumference at equal intervals. As shown in FIG. 2, these commutator pieces 12 have a pair of anchor portions 12 b at the lower part of the sliding contact portion with the brush 5, and the groove portions 12 of these anchor portions 12 b have ring rings, respectively. The varistor 13 is engaged. The ring-shaped varistor 13 is not engaged with the center of the groove 12, but is engaged with both grooves 1a of the adjacent commutator pieces 12, as shown in FIG. The groove portion 12a of the anchor portion 12b is formed in an R shape, and the ring varistor 13 and the R portion 13a are engaged between the groove portions 16 there.

  In the commutator 7, the anchor portions 12 b of the large number of commutator pieces 12, and the bush 14 that engages the ring-shaped varistor 13 and the rotary shaft 3 are integrally molded with the synthetic resin 15. It will be. Note that a connection terminal 8 to which one end of the winding of the commutator motor is connected is provided on the upper part of the commutator piece 12.

  During high-speed rotation of the armature, it is possible to prevent the ring-shaped varistor from being damaged or scattered even when a large centrifugal force is applied.

  In addition, since the ring-shaped / varistor is built in the commutator, the number of parts can be reduced, and it is not necessary to apply a resistance film to the ring-shaped varistor. Man-hours can be greatly reduced.

  In addition, the cost of the motor can be greatly reduced.

  In addition, the motor size can be greatly reduced.

  In particular, the present invention can be applied to commutator motors mounted on home appliances and electrical equipment that require high brush life and high reliability.

4 is an enlarged cross-sectional view of the main part of FIG. XX sectional view of FIG. YY sectional view of FIG. Sectional drawing of the commutator motor in Example 1 of this invention Cross section of conventional commutator motor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Winding 3 Shaft 4 Iron core 5 Brush 6 Bearing 7 Commutator 8 Armature 9 Yoke 10 Permanent magnet 11 Hook 12 Commutator piece 12a Anchor part bottom 12b Commutator piece anchor part 13 Ring shape Varistor 13a Bottom of ring-shaped varistor 14 Bush 15 Synthetic resin 16 Slit groove

Claims (5)

An arc-shaped iron core having a plurality of slots; a kneading wound and housed in the slot; an output shaft fixed through the center of the iron core in the axial direction; a base fixed to the output shaft and the base A rotor composed of a commutator including a plurality of commutator pieces arranged in the circumferential direction on the outer peripheral surface of the coil and electrically connected to ends of the windings, and a bottomed hollow housing the rotor rotatably In a commutator motor having a cylindrical shape (yoke) in which a plurality of permanent magnets are fixed to an inner peripheral surface and a plurality of brushes in contact with the surface of the commutator, the plurality of commutator piece anchors A ring-shaped varistor and a synthetic resin are integrally formed in a groove formed by the portion. A small motor characterized in that it is molded integrally with a ring-shaped varistor and synthetic resin. 2. The commutator motor according to claim 1, wherein the commutator motor is connected to a groove formed by an anchor portion of each commutator piece by the ring-shaped varistor and is fixed in position. 3. The commutator motor according to claim 2, wherein the shape of the ring-shaped varistor in which the anchor portion bottoms of the adjacent commutator pieces are R-shaped and contact each other between the slits is formed in an R-shape. 3. The commutator motor according to claim 2, wherein the shape of the ring-shaped varistor is larger in the shape of the ring-shaped varistor than the shape of the anchor in the adjacent commutator piece. An electrical equipment using the commutator motor according to any one of claims 1 to 4.

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