JPH0646858B2 - Small motor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small motor used for driving a tape of, for example, a tape recorder / video tape recorder.

Conventional technology Explaining with an example of a small motor with the highest number of contacts,
Generally, there are two types of brushes in a small motor. One is a conductive material having elasticity such as copper, beryllium copper, copper titanium alloy, phosphor bronze, nickel silver thin plate material or wire material and precious metal alloy (for example, Au, Pd, Pt,
Ag, Cu, etc. and their alloys) are clad or joined to a part of a thin plate or wire by spot welding, and the other is a part of the thin plate or wire described above. Sintered carbon brush (eg carbon,
Means such as Ag carbon, Cu carbon, Ag, Cu carbon, and those materials in which SiC, MoS ₂ , Pb, epoxy resin, etc. are mixed as an additive) are used as a conductive adhesive, spot welding, or caulking method. In small motors with these brushes, the brush sliding part vibrates unnecessarily when the commutator rotates, which causes abnormal welding on the contact surface of the brush sliding part to the commutator segment. Occurrence of foreign matter that often occurs and promotes an abnormal phenomenon called black matter (a mixture of carbon and sliding wear particles generated between the brush and commutator segment) that accompanies the occurrence of sparks. Become. As an example of a brush for a small motor,
There is one in which a brush sliding portion that comes into contact with a segment is integrally formed with a brush base portion that is supported by a supporting means provided on a lid of a motor case or the like. The contact state between the brush of that kind and the commutator segment is
Shown in the figure.

In FIG. 4, a folded brush sliding portion 3 extends from a brush base portion 2 supported by a brush supporting means 1. The brush base portion 2 and the brush sliding portion itself have elasticity and are in contact with the commutator segment 4 in a pressed state. Then, this pressing force can be set to a required value by appropriately selecting the bending angle between the brush base portion 2 and the brush sliding portion 3. The commutator segment 4 is fixed to the motor rotating shaft 6 via the commutator base 5 and rotates with the rotation of the motor.

Problems to be Solved by the Invention As described above, the commutator segment 4 which is in contact with each other
An electric spark is generated from the brush sliding part 3 at the time of rectification and due to an intermittent contact point. With the generation of the electric spark, electrical noise, wear and welding on the commutator segment 4 and the brush sliding part 3 are caused. An inconvenient state occurs such as occurrence of.

For example, when welding occurs at the position where the commutator segment 4 starts to contact and the position where the commutator segment 4 starts to separate (part a in FIG. 4)
This welded material rubs the surface of the commutator segment 4 to cause damage, and the chips generated by this rub are accumulated in the gap portion (b portion in FIG. 4) between the commutator segments 4 adjacent to each other, Therefore, the commutator and the segment are electrically connected to each other, and the rotation becomes unstable. Also, for example, if the surface roughness of the commutator segment surface becomes rough due to wear, it will cause vibration of the brush, which will promote the generation of electric sparks, further wear and wear, and cause abnormal wear. The performance of the motor itself will be degraded, such as the displacement of the commutation position.

An electric spark is best generated at the contact surface a between the brush sliding part 3 and the commutator segment 4. Of course, commutator segment 4 touches
It goes without saying that the brush sliding part 3 also suffers mechanical wear that is not caused by electric sparks.

Generally, the material of the brush sliding part 3 that is often used is a precious metal alloy or a sintered carbine as described above, and the material of the commutator segment 4 is Au, Pd, Ag.
Noble metal alloys such as AgCu, AgCd, AgCu
It is made of Cd, AgCuTi, or the like. In particular, the combination with a noble metal brush is a disadvantageous combination in which the surface energy is high and the both are substantially the same material, and thus scratches are likely to occur on the contact surface. Even when it is used in combination with a sintered carbon brush, the sliding resistance is smaller than that of a noble metal alloy brush, but a large amount of impurities such as SiO ₂ are mixed in the compound material forming the brush. There is a risk of scratches, and as with noble metal alloy brushes, noble metal alloy carbon forms an unfavorable combination in which scratches easily occur on the contact surface. The example of FIG. 5 (a) shows a structure that does not have a mechanical means for suppressing the electric sparks that are the cause of these drawbacks. That is, in the case where no vibration damping measures are taken in the brush sliding part 3, the vibration of the brush sliding part is large, the number of sparks is increased, and welding and wear are likely to occur. The example of FIG. 5 (b) shows the brush sliding part 3
Shows the configuration with vibration damping measures. That is, the vibration-proof rubber 9 is attached to the brush sliding part 3 with the adhesive 8. The vibration absorption is good at room temperature and the generation of sparks can be suppressed. However, in the vicinity of the maximum use temperature of 60 ° C., the viscosity of the pressure-sensitive adhesive decreases remarkably, the adhesive strength of the anti-vibration rubber 9 with the sliding portion 3 decreases, the vibration absorption capacity decreases, and sparks increase. However, it is difficult to obtain a good product with a long life. Further, FIG. 5 (c) shows another example of the structure in which the brush sliding portion 3 is provided with vibration damping measures as in FIG. 5 (b). That is, the vibration-proof sheet 12 is attached to the brush sliding portion 3 with the adhesive 11 having the structure in which the pressure sensitive adhesive 8 is applied to both sides of the base material 10. Compared with the example of FIG. Although the decrease in viscosity of the adhesive at high temperature can be suppressed to some extent, it is insufficient, resulting in long life at high temperature,
High quality cannot be satisfied.

The ambient temperature of this equipment is -10 ° C to +60.
Many are used at ℃.

The present invention is intended to prevent wear of a brush commutator caused by sliding of a brush of a motor and a commutator, abrasion damage due to welding, and reduction of motor life due to mechanical wear.

Means for Solving the Problems In order to solve the above problems, a brush base made of a thin plate-shaped or linear metal elastic body, and extending from this brush base, or fixed to a part of this brush base. In a small motor provided with a brush having a brush sliding portion, 2-cyclohexyl cyclohexanol (hereinafter abbreviated as the chemical of the present invention) is provided in a part of the motor case, for example, in the vicinity of the brush sliding portion on the bracket. The impregnated member such as felt is fixed by an adhesive or attached by means such as a pressure bonding method.

In addition, in order to simplify the structure of the motor, a structure may be used in which the chemical of the present invention is directly applied to the brush or the brush sliding portion.

Actions Explaining with an example of a small motor, the state in which the brush sliding part and the commutator segment are easily welded, or the state in which welding, abnormal wear, and conduction failure are likely to occur is being clarified in the literature and experiments so far. An abnormal state is likely to occur when the brush sliding part and the commutator segment slide in the atmosphere or when the commutator segment itself contains or adsorbs unsaturated cyclic hydrocarbons. At this time, it promotes an abnormal phenomenon called black matter (a carbine-like substance that is a decomposition product or a polymer formed by a mechanochemical reaction and a mixture of sliding wear particles generated between the brush and the commutator segment). Foreign matter is generated.

This foreign matter is due to the fact that when unsaturated cyclic hydrocarbons are burned by the arc between the sliding part and the commutator segment, they have a large amount of carbon per unit volume and incompletely burn, and also due to their molecular structure. However, it seems that hard carbon is formed because the bonded state of the generated carbon becomes dense.

Also, in the adsorption of hydrocarbons other than unsaturated cyclic hydrocarbons, and adsorption to commutator segments, it is due to the molecular structure, but the carbon produced is soft, which does not lead to abnormal phenomena. Has been done. Based on these phenomena, a long-term operation experiment was conducted using a commutator segment in which a very small amount of hydrocarbon was adsorbed. In this experiment, 1) there is a high probability that abnormal wear will occur in the commutator segment in the case of high temperature and low humidity.

2) When the commutator segment has adsorbed about 10 μg of unsaturated cyclic hydrocarbon such as toluene, the abnormality of the commutator segment is mitigated, and the life of the small motor is extended (however, the unsaturated cyclic carbonization is continuously performed. The results were obtained, which is the data without hydrogen replenishment.

Therefore, as a result of considering the above phenomenon, when the chemical of the present invention is used, it burns well because it has oxygen in its molecular structure unlike styrene monomer and toluene, and hard black which is one of the abnormal phenomena. It is the furthest from the formation of compounds, and becomes extremely soft even if carbon is formed, and it is possible to reduce the sliding resistance of the brush sliding part and the commutator segment.

Further, even at high temperature and low humidity where an abnormal phenomenon is likely to occur, an appropriate atmosphere matching the vapor pressure of the chemical of the present invention can be obtained in the motor case, and the hydroxyl group possessed by the chemical of the present invention causes the metal surface to Since it strongly adsorbs, a sufficient effect can be obtained.

In addition, the small motor for distributing the chemicals of the present invention has a structure close to an airtight structure in which little air flows, or the device itself in which the small motor is incorporated has a structure in which the air flow is small. To be

In the adsorption of the chemical of the present invention, Au, Pd, Pt, A
g, etc. and their alloys with strong catalytic action, not only commutator segments and brushes, but also Cu
It is also adsorbed on the surface of brushes made of etc., the surface of sintered carbon brushes, and other metal parts that compose the motor, and prevents highly reactive gases (styrene monomer, toluene, etc.) from adhering to the surface. To do. This is because the chemical | medical agent of this invention forms a hydrogen bond and strongly adsorb | sucks compared with the organic gas adsorb | sucked by the van der Waals attraction, such as styrene monomer and toluene.

The substance name and properties of the drug of the present invention are as follows: molecular formula 2-cyclohexyl = cyclohexanol: C
₁₂ H ₂₁ (OH) molecular structure: Water absorption rate: 5% (40 ° C., 90% RH, 1 atm).

The above-mentioned chemical of the present invention is adsorbed on the surfaces of the brush and the commutator segment to form a monomolecular film, so that the lubricity is extremely improved and the wear of the contact portion is significantly reduced.

Embodiment FIG. 1, FIG. 2 and FIG. 3 each show an embodiment of the present invention. Here, parts having the same names as those in FIG. 4 are given the same reference numerals. In the figure, 7 is a bearing metal, 13 is a brush, 14 is a bracket for holding the brush 13 and the like, 15 is a lower motor case, 16 is a felt impregnated with the chemical of the present invention, 17 is a magnet wire wound around a rotor core 18. , 19 are motor cases 20
It is a field magnet fixed to the inner surface of the. In the embodiment shown in FIG. 1, the felt 16 is arranged near the brush sliding portion 3 on the bracket 14, and in the embodiment shown in FIG. 2, the felt 16 is mounted on the brush base 2. In each of the embodiments shown in FIGS. 1 and 2, the brush base 3 has a brush sliding part 3 fixed to the tip of the brush base 2.
It is also possible to provide a brush sliding portion bent and extended from the above, and to mount the felt 16 on the sliding portion.

Further, in each of the embodiments, the atmosphere in the motor case becomes a vapor atmosphere of the chemical of the present invention, and the chemical of the present invention is adsorbed on the surface of the brush and the commutator segment. The following Comparative Examples and Examples were tested. Comparative Example 1) Conventional product Comparative example 2) Test product in styrene monomer atmosphere Comparative example 3) Test product in toluene atmosphere Example 1) Book The result of the test article in the chemical atmosphere of the invention is shown.

In addition, even if the chemical composition of the present invention contains some impurities,
The chemical | medical agent of this invention exhibits a remarkable effect.

The test results are shown in the table below.

The motor used for the test will be described with reference to the motor shown in FIG. This motor is a direct current motor, with an outer diameter of 30 mm and a height of 25 mm, the rated output is 0.1 W, and the operating condition during the test is 4.2 VD.
C, 25 mA.

If the polyester felt 16 washed with a polyfluoroethylene liquid and degreased and impregnated with the chemical of the present invention is installed in the gap of this motor, the chemical of the present invention will gradually evaporate and a remarkable effect can be obtained. Was completed. The polyester felt 16 can control the evaporation speed by changing the thickness of the fibers and the apparent specific gravity. Even if a sponge of continuously foamed plastic or rubber was used instead of the polyester felt 16, a remarkable effect could be obtained.

In addition, a sintered porous field magnet 19
What is impregnated with the chemical of the present invention is 0.1 to 0.
With a holding power of 3 g, a remarkable effect could be obtained. Also, similarly, those blended with the plastic bracket 14, blended with the plastic commutator base 5, impregnated with the magnet wire 17, blended with the oil of the metal of the bearing metal 7, Those impregnated in the gap between the magnet 19 and the motor case 20, blended with the anti-vibration rubber 9, blended with the anti-vibration rubber sticking adhesive 8 shown in FIG. 5, and gas permeable film such as polyethylene. Alternatively, a device enclosed in a case and installed in a small motor also has a force to hold the chemical of the present invention, and a remarkable effect can be obtained.

Further, since the chemicals of the present invention are solid at room temperature, it is necessary to raise the temperature to the melting point when impregnating parts, but it is easy to use by dissolving them in 2-methyl-2,4-pentanediol having the same effect. Impregnation was possible and a remarkable effect could be obtained.

FIG. 6 shows a rectified waveform of the small motor of the present invention. (A) is a rectified waveform of a conventional product before the test in a 60 ° C., 5% RH atmosphere, and a rectified waveform of Comparative Example 1 after a 300-hour test (b) ) Is a rectification waveform before the test at 60 ° C., 5% RH atmosphere in an unsaturated cyclic hydrocarbon styrene monomer atmosphere and 1
The rectified waveform (c) of Comparative Example 2 after the 00 hour test is the rectified waveform before the 5% RH atmosphere test at 60 ° C. when the unsaturated cyclic hydrocarbon (toluene) is adsorbed on the surface of the commutator segment in an amount of about 10 μg.
Rectified waveform of Comparative Example 3 after 0-hour test (d) shows the rectified waveform before the 5% atmosphere test at 60 ° C. in the chemical atmosphere of the present invention and the rectified waveform of Example 1 after the 1500-hour test.

EFFECTS OF THE INVENTION As is apparent from the above description, the present invention has the following effects.

1) The chemicals of the present invention are adsorbed on the surfaces of the brush and the commutator segment to exert a lubricating effect, and have an effect of preventing abnormal wear or welding of the contact surface of the embroidery and the resulting abrasion damage.

2) Even if there is an organic gas having a benzene ring such as styrene monomer or toluene, it is protected by the chemical film of the present invention adsorbed on the surface of the brush and commutator segment, and the generation of black matter becomes minimal, and the brush and commutator segment It is possible to prevent contact failure between the two. In addition, since contact failure does not occur, the generation of electrical noise is reduced and the speed of a small motor is stabilized, resulting in 1-30V.
Reduces wow and flutter in equipment that uses small motors for relatively low voltage.

3) When a micromotor having an operating voltage of 1 to 30 V and a current value of about 100 mA, which is commonly used due to the lubricating action of the chemicals of the present invention, is operated in an atmosphere of the chemicals of the present invention, the current value decreases by 5 to 10%, Energy saving can be achieved.

4) The chemical of the present invention has a damping effect of suppressing the vibration generated by the sliding motion of the brush and the commutator.
It enables reduction of mechanical noise by 10%. That is, it has almost the same sound deadening effect as the anti-vibration rubber normally attached to the brush.

5) As for the hygroscopicity of the chemicals of the present invention, the ideal balance is between -OH group having hydrophilicity and -C-C- (carbon bond part) having hydrophobicity, and the atmosphere is 40 ° C and humidity 90% RH. Above all, the water absorption is 20% or less, and the lubricating effect is large without being wet enough to corrode the metal.

6) When the chemical | medical agent of this invention is used after melt | dissolving in 2-methyl-2,4-pentanediol, it becomes possible to impregnate a part at normal temperature, it is excellent in productivity, and the effect is long-lasting.

[Brief description of drawings]

1 and 2 are configuration diagrams of an embodiment of the present invention, FIG. 3 is a half sectional view of a motor of an embodiment of the present invention, and FIG.
FIG. 5 is a diagram showing a configuration of a general brush and a commutator, FIGS. 5 (a) to 5 (c) are diagrams showing a typical configuration of a conventional brush sliding portion, and FIG. 6 is a small motor according to the present invention. It is a figure which shows the rectification waveform of. 3 …… Commutator sliding part, 4 …… Commutator ・
Segment, 14 ... bracket, 16 ... felt,
20 ... Motor case.

Claims (2)

[Claims] 1. A small motor having a brush mechanism section and a commutator, wherein the brush and the commutator slide, wherein the motor case has an atmosphere of 2-cyclohexyl = cyclohexanol. 2. A small motor according to claim 1, wherein 2-cyclohexyl cyclohexanol is used after being dissolved in 2-methyl-2,4-pentanediol.