JPS62195090A - Lubricant - Google Patents

Abstract

PURPOSE:To provide a lubricant composed of a vapor mixture of 2-methyl-2,4- pentanediol and 1,4-butanediol and to be applied to a contacting or sliding surface of e.g. a miniature motor for magnetic tape drive, a vertically moving contact, a slide switch or a relay, etc. CONSTITUTION:The objective lubricant is composed of vapor of a mixture of 2-methyl-2,4-pentanediol and 1,4-butanediol (having a water-absorption of 8% at 40 deg.C and 90% RH under 1atm). EFFECT:The lubricant is effective in preventing abnormal abrasion or welding of contacting or sliding surface and abrasion damage caused thereby, suppressing the formation of black material to prevent contact failure and suppressing the generation of electrical noise. It has damping effect.

Description

[Detailed Description of the Invention] Industrial Fields of Application The present invention is applicable to small motors used to drive tapes in tape recorders, video tape recorders, etc., as well as vertically movable contacts, slide switches, relays, connectors, etc. This relates to lubricants used for electrical contacts or sliding parts.

To explain this using the example of a small morph that has the highest number of contact openings and closings in conventional technology,
In general, the brushes in small motors are thick (there are two types. One is a thin sheet material made of an elastic conductive material, such as copper, helium copper, copper titanium alloy, phosphor bronze, or nickel silver, or a wire material made of a noble metal alloy). For example, Au, Pd, Pt,
The structure is made by cladding (Ag, Cu, etc. and their alloys) or by spot welding a part of the thin plate material or wire rod. Sintered carbon brush (e.g. carbon,
Ag carbon, Cu carbon, AgCu carbon, and SiC, M for those materials.

(sz, pb, epoxy resin, etc. as additives) is formed using conductive adhesive, spot welding, or caulking method, but in small motors with these brushes, the commutator rotation Sometimes, the brush sliding part vibrates unnecessarily, which causes abnormal welding on the contact surface of the brush sliding part with the commutator segment, and blackening (carbon and・A mixture of sliding wear particles generated between
This is a problem because foreign substances that promote abnormal phenomena often occur. An example of a brush for a small motor is one in which a brush sliding portion that comes into contact with a commutator segment is integrally formed with a brush base that is supported by support means provided on a lid of a motor case or the like. The state of contact between such a brush and the commutator segment is shown in FIG.

In FIG. 4, a bent brush sliding portion 3 extends from a brush base 2 supported by a brush support means 1. The brush base 2 and the brush sliding portion themselves have elasticity and are in contact with the commutator segment 4 in a pressed state. This pressing force can be set to a required value by appropriately selecting the bending angle between the brush base 2 and the brush sliding portion 3. Further, 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 In this way, the commutator segments 4 that are in contact with each other
and the brush sliding part 3 during rectification and at the contact point.
! Electric sparks are generated by Jim, and with the generation of electric sparks, electric noise, commutator segment 4,
Inconvenient conditions such as wear and welding occur in the brush sliding portion 3 occur.

For example, if welding occurs at the position where it starts to make contact with the commutator segment 4 and at the position where it leaves (section a in Fig. 4),
This welded material scrapes and damages the surface of the commutator segment 4, and furthermore, chips generated by this scraping accumulate in the gap between adjacent commutator segments 4 (section b in FIG. 4). Therefore, conduction occurs between the commutator segments, resulting in unstable rotation.

For example, when the surface roughness of the commutator segment surface becomes rough due to wear, it causes brush vibration, which promotes the generation of electrical sparks, which further progresses wear and causes abnormal wear, electrical noise, and rectification. The performance of the motor itself will deteriorate due to positional deviation.

Incidentally, electric sparks are most often generated at the contact surface a between the brush sliding portion 3 and the commutator segment 4. Of course, the commutator + component 4 that comes in contact with
Needless to say, mechanical wear that is not caused by electric sparks also occurs in the brush sliding portion 3.

Generally, the material of the brush sliding part 3 that is often used is a noble metal alloy or sintered carbon as mentioned above.
The materials of commutator segment 4 are Au, Pd, and A.
noble metal alloys such as AgCu, AgCd, AgC
It consists of uCd, AgCuTi, etc. In particular, when used in combination with a noble metal brush, since both have high surface energy and are made of substantially the same material, this is an unfavorable combination that tends to cause abrasions on the contact surfaces. In addition, even when combined with a sintered carbon brush, although the sliding resistance is lower than that of a noble metal alloy brush,
The blended materials that make up the brush contain a considerable amount of impurities such as SiO□, which poses a risk of scratches.
Also, as in the case of noble metal alloy brushes, the use of noble metal alloy carbon is an unfavorable combination in that scratches are likely to occur on the palm contact surface. The example of FIG. 5(a) shows a structure without mechanical means to suppress the electrical sparks that cause these defects. That is, if no vibration damping measures are taken for the brush sliding part 3, the vibration of the brush sliding part will be large, sparks will be generated more often, and welding and wear will easily occur. The example in FIG. 5(b) shows a configuration in which vibration damping measures are taken for the brush sliding section 3. That is, vibration isolating rubber 9 is attached to brush sliding part 3 with adhesive 8, and vibration absorption is good at room temperature, and generation of sparks can be suppressed. However, at temperatures close to the upper limit of 60°C, the viscosity of the adhesive decreases significantly, and vibration-proof rubber 9
The adhesive force with the sliding part 3 is reduced, the vibration absorption ability is reduced, and sparks are generated more frequently, making it difficult to obtain a product with a long life and excellent quality. Furthermore, FIG. 5(c) is
) shows another example of a structure in which vibration damping measures are taken for the brush sliding part 3. That is, a vibration isolating sheet 12 is attached to the brush sliding part 3 using an adhesive 11 having an adhesive 8 applied to both sides of a base material 10, as shown in FIG. 5(b) above.
Compared to the above example, although the decrease in the viscosity of the adhesive at high temperatures is suppressed to some extent, it is insufficient, and it is not possible to satisfy long life and high quality at high temperatures.

The ambient temperature for this device is -10°C to +6°C.
Many are used at 0°C.

The purpose of the present invention is to smoothly slide electric contacts or sliding parts such as vertical switches and relays with an open/close contact structure, rectifying mechanisms of small motors, slide switches with sliding contact structures, and connectors. That is.

Means for Solving the Problems In order to solve the above problems, the present invention uses 2-methyl-2,4-pentanediol and 1,4-butanediol as lubricants to be attached to the surface of the sliding part. A mixture (hereinafter abbreviated as the chemical of the present invention) is used.

In addition, in order to simplify the structure, a structure in which the coating is applied directly to the sliding portion may be used.

Taking the example of a small working motor, past literature and experiments are beginning to clarify the conditions in which brush sliding parts and commutator segments tend to weld, or conditions in which welding, abnormal wear, or poor continuity occur. Conditions where abnormalities are likely to occur are the atmosphere in the area where the brush moving part and the commutator segment move, or the presence or adsorption of unsaturated cyclic hydrocarbons in the commutator segment itself. be. At this time, an abnormal phenomenon called black matter (a mixture of decomposition products or carbon-like polymers produced by mechanochemical reactions, and dynamic wear particles generated between the brush and the commutator segment) occurs. Foreign matter is generated that promotes

This foreign material is burned when the unsaturated cyclic hydrocarbon is combusted by an arc between the sliding parts and the commutator segment.
This is thought to be due to incomplete combustion due to the large amount of carbon per unit volume, and due to its molecular structure, but the bonding state of the produced carbon becomes dense, resulting in the formation of a hard carphone.

In addition, when hydrocarbons other than unsaturated cyclic hydrocarbons are adsorbed in the atmosphere and on the commutator segment, the carbon produced is soft, which is due to its molecular structure, and will not lead to abnormal phenomena. has been clarified. Based on these phenomena, a long-term operation experiment was conducted using a commutator segment that adsorbed a small amount of hydrocarbons. In this experiment, 1) there is a high probability that abnormal wear will occur in the commutator segment under high temperature and low humidity.

2) If about 10 μg of unsaturated cyclic hydrocarbons such as styrene monomer and toluene are adsorbed on the commutator segment, abnormalities in the commutator segment will be alleviated and the life of the small motor will be extended. (However, this data is for the case where there is no continuous supply of unsaturated cyclic hydrocarbons.) The results were obtained.

Therefore, when the chemical of the present invention is used, unlike styrene monomer or toluene, it burns well because it has oxygen in its molecular structure, and is the least likely to prevent the formation of hard black particles, which is one of the abnormal phenomena. Even if carbon is generated, it becomes extremely soft and can reduce the sliding resistance of the brush sliding part and the commutator segment.

Furthermore, even at high temperatures and low humidity where abnormal phenomena are likely to occur, an atmosphere suitable for the vapor pressure corresponding to the partial pressure of each of the two components constituting the chemical of the present invention can be created within the motor case. Since the chemical of the invention strongly adsorbs to the metal surface due to the hydroxyl group, sufficient effects can be obtained.

In addition, better results will be obtained if the small motor in which the chemical of the present invention is placed has a nearly hermetic structure with little air circulation, or if the device itself in which the small motor is installed has a structure with little air circulation. .

In addition, in the adsorption of chemicals of the present invention, Au, Pd, Pt,
Commutator segments and plushes using highly catalytic materials such as Ag, etc. and their alloys as well as C.
It also adsorbs to the surfaces of brushes made of aluminum, sintered carbon brushes, and other metal parts that make up the motor, and highly reactive gases (styrene monomer, 1
- luene, etc.) from adhering to the surface. This is 2-
This is because methyl-2,4-pentanediol and 4-butanediol form hydrogen bonds and are strongly adsorbed, compared to organic gases such as styrene monomer and toluene, which are adsorbed by van der Waals attraction. The substance name and properties of the drug of the present invention are as follows: Molecular formula = 2-Mediru-2,4-pentanediol
C6111z (OH) zl, 4-butanediol C441a (011) z Water absorption rate = 8% (40℃・90
%RH・1 atm).

The aforementioned chemicals of the present invention are adsorbed onto the surfaces of the brushes and commutator segments to form a monomolecular film, thereby greatly improving lubricity and significantly reducing wear on the contact parts.

The same effect can also be achieved in electrical contacts such as vertical switches and relays with an open/close contact structure, slide switches and connectors with a sliding contact structure.

Embodiment FIGS. 1, 2 and 3 each show an embodiment in which the present invention is applied to a small motor. Here, parts with the same names as those in FIG. 4 are given the same reference numerals. In the figure, 7 is the bearing metal, 13 is the brush, 14
15 is the bottom of the morph case; 16 is felt impregnated with the chemical of the present invention; 17
is the magnet wire wrapped around the rotor core 18, 19
is a field magnet fixed to the inner surface of the morph case 20. In the embodiment shown in FIG. 1, the felt 16 is placed near the brush sliding part 3 on the bracket 14, and in the embodiment shown in FIG. In the embodiment, the brush 13
It is installed in Case 20, which is far away from the

Further, in each of the embodiments, the atmosphere inside the case becomes a vapor atmosphere due to the chemical of the present invention, so that the chemical of the present invention is adsorbed onto the surfaces of the brush and the commutator segment.

Tests were conducted on the following comparative examples and examples.

Comparative example 1) Conventional product Comparative example 2) Test product in a styrene monomer atmosphere Comparative example 3) Test product in a toluene atmosphere Example 1)
A test product in an atmosphere containing a mixture of 2-methyl-2,4'-pentanediol and 4-butanediol in a ratio of 1=1.
The drug of the invention exhibits remarkable effects. The test results are shown in the table below.

The motor used in the margin test will be explained below with reference to FIG. This motor is a DC motor with an outer diameter of 30 mm and a height of 25 mm, with a rated output of 0. IW, the operating conditions during the test were 4.2VDC.
It is 125mA.

If a polyester felt 16 that has been cleaned and degreased with a polyfluoroethylene solution is impregnated with the chemical of the present invention in the gap of the motor, the chemical of the present invention will gradually evaporate, resulting in a remarkable lubrication effect. I was able to do it. The evaporation speed of the polyester felt 16 can be controlled by changing the thickness and apparent specific gravity of its fibers. Remarkable effects could also be obtained by using an open-cell foamed plastic or rubber sponge instead of the polyester felt 16.

Moreover, the sintered porous field magnet 19 impregnated with the chemical of the present invention has a temperature of 0°1 to 0.3
It had a holding power of 1.5 g, and a remarkable effect could be obtained.

Furthermore, a device sealed in a gas permeable film or case such as polyethylene and installed inside a small motor also had the ability to retain the chemical of the present invention, and was able to obtain a remarkable lubrication effect.

In addition, the chemical of the present invention has the following features: (1) 2-methyl-2,4-pentanediol has a high evaporation rate.

(2) 4-butanediol has a slow evaporation rate but compensates for its high hygroscopicity.

Therefore, depending on the conditions in which the motor is used, it is 1:4 to 7:1.
It exhibits excellent physical properties when used at a mixing ratio of . 1:4
indicates the limit of hygroscopicity and 7:1 indicates the limit of persistence.

Next, the evaporation rate is shown in FIG.

The conditions were an ambient temperature of 60°C and humidity of 5%. The sample is 100CC
Pour 10 gr into a beaker. Also, cover the beaker with an opening ratio that matches the motor usage conditions.

(1) to (5) in the figure indicate the mixing ratio of (2-methyl-2,4=bentanediol): (1',' 4-butanediol), ('1) O: 100 (2) l: 4 (3) l: 1 (4) 7: 1 (5) 100: O.

FIG. 7 shows a rectified waveform diagram of the small motor for the chemical of the present invention.

(a) is the rectification waveform of the conventional product before the test in an atmosphere of 60°C and 5% RH. (b) is the rectification waveform of Comparative Example 1 after the 300-hour test in the atmosphere of unsaturated cyclic hydrocarbon styrene monomer. ℃, 5% RH atmosphere test before rectification waveform and 1
The rectification waveform (C) of Comparative Example 2 after the 00 hour test is the rectification waveform before the 60°C, 5% RH atmosphere test when approximately 10 μg of unsaturated cyclic hydrocarbon (toluene) is adsorbed on the surface of the commutator segment, and
The rectification waveform (d) of Comparative Example 3 after the 0-hour test is the rectification waveform before the 60°C 15% atmosphere test in the chemical atmosphere of the present invention, and the rectification waveform before the 60°C 15% atmosphere test in the chemical atmosphere of the present invention. According to this, the following effects are achieved.

1) By adsorbing the chemical of the present invention to the surface of the sliding part, a lubricating effect is exerted, which has the effect of preventing abnormal wear and welding of the sliding surface and the resulting abrasion damage.

2) Even if there is an organic gas with a benzene ring such as styrene monomer or toluene, it will be protected by the film of the chemical of the present invention adsorbed on the surface of the sliding part, and the formation of black particles will be minimal, resulting in poor contact between the contacts. can be prevented. In addition, since contact failure does not occur, the generation of electrical noise is also reduced, and when used in small motors, for example, the speed can be stabilized. 3) The chemical of the present invention has a damping effect that suppresses vibrations generated by the sliding motion of the brush commutator, reducing wow and flutter in equipment in which the motor is used, and reducing wow and flutter by 1 to 10%.
This makes it possible to reduce mechanical noise.

4) The hygroscopicity of the chemical of the present invention has an ideal balance between the hydrophilic 1OH group and the hydrophobic 1C-C- (carbon bond), even in an atmosphere of 40°C and 90% RH. The water absorption rate is 20% or less, and the lubricating effect is large without being so wet that it corrodes the metal.

5) The hygroscopicity of the chemical of the present invention has an ideal balance between the hydrophilic 1OH group and the hydrophobic 1C-C-<carbon bond, and 2-methyl-2 has a fast evaporation rate. ，
4-pentanediol exhibits its effect first, and then 4-butanediol, which has a slow evaporation speed, exhibits its effect, resulting in an excellent product with a long duration of effect.

[Brief explanation of drawings]

1 and 2 are block diagrams of an embodiment in which the present invention is applied to a small motor, FIG. 3 is a half-sectional view of a motor according to an embodiment of the present invention, and FIG. 4 is a general brush, A diagram showing the configuration of a commutator, FIGS. 5(a) to (c) are diagrams each showing a typical configuration of a brush sliding part in a conventional example, and FIG. Figure, 7th
Figures (a) to (d) are diagrams showing rectified waveforms of a small motor in which the effects of the present invention were confirmed. 3... Commutator sliding part, 4...
- Commutator segment, 16...Felt, 20...Motor case. Name of agent Patent attorney Toshio Nakao Name 3 --- Blank 5 11 Figure 16 --- Furt Figure 2 Figure 5 Figure 6

Claims (1)

[Claims] A lubricant, characterized in that the lubricant to be applied to the surface of electrical contacts or sliding parts is in an atmosphere of vapor of a mixture of 2-methyl-2,4-pentanediol and 1,4-butanediol.