JPH079073U - Commutator with varistor - Google Patents

Abstract

(57) [Abstract] [Purpose] Providing a commutator with a varistor that does not require soldering work during mounting, has no rotational imbalance, and is not damaged during rotation. [Composition] The electrode plate 1 is attached to one end
A substantially cylindrical holding body 11 in which the third engaging portion 17 is formed,
A varistor 12 attached to the holder 11 is provided, and recesses 11a, 11b, 11 are formed on the outer periphery of the holder 11 at equal intervals in the direction of the armature shaft 15 at predetermined angles.
c is formed, two electrodes 12a and 12b are formed on the varistor 12 at a predetermined interval, and the recess 1 of the holding body 11 is formed.
The varistor 12 is fitted into the varistors 1a, 11b, and 11c, and the electrode plate 13 is attached to the outer periphery of the varistor 12 in contact with the varistor 12.
Is engaged with the engaging portion 17 on one end side, and the other end side of the electrode plate 13 is fitted to the outer peripheral surface of the holding body 11 by the fixing ring 14.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a commutator with a varistor, and more particularly to a commutator that prevents electromagnetic noise generated from a motor.

[0002]

[Prior art and its problems]

 Conventionally, as a noise prevention for a small motor, a technique of attaching a ring varistor to a commutator coil attachment portion by soldering, a technique of using a cylindrical varistor as a commutator (see Japanese Patent Laid-Open No. 103055), etc. have been known. There is. However, the technique of mounting the above ring varistor requires a soldering process to the coil mounting portion.

Then, a holding component in the commutator of the ring varistor, a work process for determining the relative position of the varistor, a soldering process for fixing the varistor to the holding component for energizing, and the like are required.

Generally, a varistor is a ceramic component, and it has a drawback that it is difficult to assemble because it suffers from defects such as cracking and chipping depending on impact load. Therefore, a technique using a cylindrical varistor as a commutator (Japanese Utility Model Publication No. 55-76683, Japanese Utility Model Publication No. 61-185264, etc.) has been proposed.

However, in these proposed techniques, it is difficult to directly press fit the armature shaft to the armature shaft because the varistor is made of ceramic. As a result, the cylindrical surface of the cylindrical varistor has a large eccentricity with respect to the rotation of the shaft, resulting in poor contact between the commutator and the brush, resulting in an increase in electromagnetic noise.

There is also known a technique in which a resin or the like is mixed into the varistor component in order to press-fit it into the motor shaft, and after press forming the varistor, the press-fitting dimension is obtained by cutting, but only the varistor component is mixed by mixing the resin or the like. There is a problem that the noise absorption effect is inferior to the case of.

Further, in the usage state of the varistor, none of the varistor bodies is effectively used. That is, taking the case of 3 slots as an example, the conventional varistor has electrodes 41, 42, 43 provided on the donut-shaped varistor body 40 as shown in FIGS. The terminals of are connected and assembled.

As a result, a brush (not shown) absorbs electromagnetic noise generated during rectification. At this time, in the varistor, the noise current flows only in the region 44 in which no electrode is provided as shown in FIG. 5, and the varistor body is used in a state where no current flows in other parts. have.

An object of the present invention is to provide a commutator with a varistor that does not require soldering work at the time of mounting, has no rotational imbalance, and is not damaged during rotation. Another object of the present invention is to provide a commutator with a varistor in which the area of the varistor which is not useful for noise absorption can be significantly reduced and the mass of the rotating part is reduced.

[0010]

[Means for Solving the Problems]

 A commutator with a varistor according to the present invention comprises a substantially cylindrical holding body which is attached to an armature shaft and has an engaging portion with an electrode plate formed on one end side, and a varistor attached to the holding body. The holding body is provided with dents on the outer periphery of the holding body at equal intervals in the armature shaft direction, and two electrodes are formed on the varistor at predetermined intervals. The electrode plate is mounted by inserting the varistor into contact with the varistor on the outer periphery of the varistor, and one end side of the electrode plate is engaged with the engaging portion on one end side of the holding body to The other end side of the plate is characterized by being fitted to the outer peripheral surface of the holding body by a fixing ring.

[0011]

In the present invention, recesses are formed on the outer periphery of the holder at equal intervals in the armature shaft direction, and two electrodes are formed on the varistor at predetermined intervals, so that the holder has recesses. Insert the varistor into the varistor and contact the varistor on the outer periphery of the varistor to attach the electrode plate.One end of the electrode plate engages with the engaging part on one end side of the holder, and the other end of the electrode plate. Since the side is configured to be fitted to the outer peripheral surface of the holding body by the fixing ring, it has a simple configuration in which a varistor is fitted inside the electrode plate of the commutator, and when mounting the varistor to the commutator, soldering at the time of mounting No work required. Since the varistor is only the part that fits into the recess, the area of the varistor that is not useful for noise absorption can be greatly reduced, and the mass of the rotating part can be reduced. Also, since the varistor is covered by the electrode plate, it is not damaged during rotation and reliability is improved.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. The parts, arrangements, etc. described below do not limit the present invention and can be variously modified within the scope of the present invention.

FIGS. 1 to 3 show an embodiment of the present invention, which is not shown in the present embodiment but is applied to a DC motor having a slot of 3 poles. 2 is a sectional view taken along the line BB of FIG. 2, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a perspective view of the varistor.

The commutator 10 with a varistor according to this example has a holder 11, a varistor 12, an electrode plate 13, and a fixing ring 14 as main constituent elements.

The holding body 11 of this example is made of synthetic resin and has a substantially cylindrical shape with a mounting hole 16 for fitting the armature shaft 15 in the center, as shown in FIGS. 1 and 2. Since this is a three-pole slot in this example, three recesses 11a, 11b, 11c having a circular arc angle of 60 ° are formed on the outer circumference at equal intervals on the outer circumference. . Further, an overhanging portion 19 is formed at one end (lower side in FIG. 1), and this overhanging portion 19 serves as an engaging portion of an electrode plate 13 described later, and is about 60 ° from each of the depressions 11a, 11b, 11c. Three connecting holes 17 are formed at different positions (one connecting hole is shown in FIG. 1).

As shown in FIG. 3, the varistor 12 of this example has a circular arc-shaped cross section obtained by dividing a cylinder in the armature shaft direction, and has a predetermined interval so that two electrodes are applied to the curved outer peripheral surface. Two electrodes 12a and 12b are formed via the portion 18. The spacing portion 18 is configured as a predetermined spacing portion 18 having a size that affects the characteristics of the varistor 12. In this example, three varistor 12 are used.

The electrode plate 13 of the present example has a circular arc-shaped cross section obtained by dividing a cylinder formed of a thin copper plate in the armature shaft direction, and has a connection terminal 13 a for connecting a winding (not shown) at one end side. Is formed in a substantially right-angled direction and has three pole slots, so three slots are used.

In the fixing ring 14 of this example, a mounting hole 14a is formed in the center, and an outer peripheral end portion is bent at a substantially right angle to form an engaging portion 14b.

Next, the assembling of the embodiment having the above configuration will be described. First, three varistor 12 are fitted into each of the depressions 11a, 11b, 11c formed in the holding body 11. Next, the electrode plate 13 is assembled to the outer periphery of the varistor 12 and the holding body 11. At this time, the electrode plate 13 and the varistor 12 are brought into contact with each other so that the electrodes on the adjacent sides of the adjacent varistor 12 are connected to each other. The connection terminal 13 a of the plate 13 is inserted into the connection hole 17 of the holder 11. The other electrode plates 13 are assembled in the same manner.

By doing so, as shown in FIG. 2, the holding body 11, the varistor 12, and the electrode plate 13 are arranged with the gap 18 between the electrodes 12a 1 and 12b formed on the varistor 12 left. In this state, the electrodes 12a and 12b provided on all the varistor 12 come into contact with the electrode plate 13. Next, using the fixing ring 14, as shown in FIG. 1, the end portion of the electrode plate 13 opposite to the connection terminal 13a is fixed.

In addition, the electrodes 12 a and 12 b of the varistor 12 of this example are formed by coating a base with copper or silver plating or paste and baking it before assembling the varistor 12. Then, after baking, solder having a minute thickness is applied on the upper side.

Therefore, after assembly, the electrodes of the varistor 12 that are in contact with the electrode plate 13 by slight heating can be electrically connected by soldering without a soldering step. It will be suitable. Although the example of the three-pole slot is shown in this example, it is needless to say that the number of slots can be changed by using the same number of varistors 12 as the electrodes of the commutator 10.

Further, if the dimensional accuracy of the outer peripheral surface of the holder 11 of the commutator 10 is the same as the conventional accuracy, the unevenness of the electrode plate 13 of the commutator 10 and the amount of eccentricity can be made the same as the conventional one. It is possible to eliminate the rotational imbalance that occurs when the armature varistor 12 is assembled.

[0024]

[Effect of device]

 As described above, the commutator with a varistor according to the present invention has a simple structure in which the varistor is fitted inside the electrode plate of the commutator. It can be unnecessary. Further, in the present proposal, since the varistor is fitted in the recessed portion, the area of the varistor which is not useful for noise absorption can be greatly reduced and the mass of the rotating portion can be reduced. Also, since the varistor is covered by the electrode plate, damage during rotation is eliminated and reliability is improved.

[Brief description of drawings]

1 is a cross-sectional view taken along the line BB of FIG. 2, showing an embodiment of a commutator with a varistor according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view of a varistor.

FIG. 4 is a perspective view of a varistor showing a conventional example.

5 is a cross-sectional view taken along line CC of FIG.

[Explanation of symbols]

 10 commutator with varistor 11 holder 11a, 11b, 11c recess 12 varistor 12a, 12b electrode 13 electrode plate 13a connection terminal 14 fixing ring 14a mounting hole 14b engaging part 15 armature shaft 16 mounting hole 17 engaging part (connecting hole) 18 Predetermined interval part

Claims (1)

[Scope of utility model registration request] 1. A varistor having a substantially cylindrical holding body attached to an armature shaft and having an engaging portion with an electrode plate formed on one end side, and a varistor attached to the holding body. In the commutator, recesses are formed on the outer periphery of the holder at regular intervals in the armature shaft direction, two electrodes are formed on the varistor at predetermined intervals, and the varistor is formed in the recess of the holder. And the electrode plate is attached to the outer circumference of the varistor by contacting the varistor, and one end side of the electrode plate engages with the engaging portion on one end side of the holding body, and the other end The side is a commutator with a varistor which is fitted to the outer peripheral surface of the holding body by a fixing ring.