KR20060113346A - Carbon brush for electrical machine - Google Patents

Abstract

Disclosed is a carbon brush for electrical machines (1) which is pressed against a conductive rotating body (2). The brash base of this carbon brush is composed of a material containing an aggregate including carbon as at least a component and a binder. To this brash base, there is added 0.2-10 weight% of a water- soluble lubricant, or 0.2-3 weight% of a fluorine-modified silicone oil, or 0.2-10 weight% of a water-soluble lubricant and a metal compound.

Description

Electromechanical Carbon Brush {CARBON BRUSH FOR ELECTRICAL MACHINE}

The present invention relates to an electromechanical carbon brush, and more particularly to an electromechanical carbon brush used in a small motor.

Electric motors are progressing in miniaturization, large capacity, and high output. For example, motors used in vacuum cleaners are required to be more compact and have a strong suction force. For this reason, the outer diameter of a motor fan is made small and it rotates at the ultrahigh speed (30,000 rpm or more). In such a high-speed rotation motor, maintaining a good sliding state between an electromechanical carbon brush (hereinafter referred to as a brush) and a commutator that is a conductive rotating body has been an important problem to maintain normal electrical contact.

Conventionally, in view of such a problem, many so-called resin bond brushes which combine graphite powder with a synthetic resin have been used. This resin bond type brush is secured by the graphite powder, and the left-hand property is improved by the resin, thereby ensuring normal electrical contact.

In addition, in a vacuum cleaner or the like, in order to increase the suction force (suction work rate), it is possible to increase the current density of the brush by increasing the input of the motor. However, in such a method, in particular, the resin bond type brush may cause a commutation defect due to the temperature increase of the brush or the increase of the wear of the brush due to prolonged use.

In addition, the background of input regulation must be taken into account, and a motor for obtaining a higher output with respect to a constant input is further required.

From such a situation, the brush which can ensure stable rectification and give high efficiency (output to an input) with respect to a motor is anticipated strongly.

As a countermeasure for such a problem, Japanese Patent Laid-Open No. 2002-56944 (hereinafter referred to as Patent Document 1) discloses a method of partially lowering the specific resistance of the brush by applying metal plating such as copper to the brush surface. In this method, by decreasing the resistivity of the vortex of the brush, the rise of the temperature of the brush is suppressed, the rectification is stabilized, the wear of the brush is reduced, and higher motor efficiency is obtained.

In addition, US Patent No. 6068926 (hereinafter referred to as Patent Document 2) discloses a method of improving brush wear characteristics by impregnating silicone oil into pores of a brush. In this method, since the sliding property of a brush and a commutator is improved, the temperature rise of a brush is suppressed and abrasion of a brush is reduced.

In the technique of these publications, wear of the brush is suppressed and life of the brush is expected to be long. However, in the method disclosed in Patent Literature 1, the rectification is stable and the brush temperature rises and the brush wear is reduced. However, since the metal surface is partially applied to the brush surface to lower the specific resistance, there is a limit to improving the efficiency of the motor. Is happening. In other words, the improvement of the efficiency of the motor and the life of the brush caused by the rectification is stabilized by the action of the metal plating applied around the brush was stopped.

In addition, although the temperature increase of a brush and brush wear are reduced by the method shown by patent document 2, since it is impregnated into the pore of a brush by making silicone oil into an emulsion, it is difficult to impregnate a silicone oil uniformly in the pore of a brush, and a stain is It was happening. As a result, there was a possibility that good sliding properties of the brush and the commutator could not be secured and stable rectification could not be secured.

In view of such a situation, the present invention provides an electromechanical carbon brush that can achieve a more stable rectification and achieve high efficiency, long life, a reduction in temperature, a suppression of sliding noise, and a reduction in commutator wear for a motor. The purpose.

In order to solve the above problems, the electromechanical carbon brush of the present invention is an electromechanical carbon brush which is pressed against a conductive rotating body, and the material comprising an aggregate and a binder containing carbon as at least one component is used as a brush base material. The water-soluble lubricant is contained in the electromechanical carbon brush, and the content of the water-soluble lubricant is 0.2 to 10% by weight based on the carbon brush base material.

This configuration provides an electromechanical carbon brush capable of imparting high efficiency, long life, reduction of temperature, suppression of sliding sound, and reduction of commutator wear for a motor, thereby achieving the above object.

The brush base material comprised of an aggregate and a binder exists in the space | gap part called "pores", but impregnation here means making water-soluble lubricant exist in the said material in the pore.

In addition, the size and volume of the pores present vary depending on the type of brush, the manufacturing method and the manufacturing conditions. The pores exist in the entire brush, and there are open pores extending from the brush surface to the inside, and there are separate closed pores in the brush. Hereinafter, when simply referred to as "pores," it means open pores.

Thus, since the water-soluble lubricant is an aqueous solution, the water-soluble lubricant can be impregnated in the pores of the brush in the size of the molecular level. In addition, the water-soluble lubricant has a surface active action, the surface tension is lowered, it is easy to penetrate inside the fine pores by the capillary phenomenon. Thus, the water soluble lubricant can be impregnated in the fine pores of the brush, and is also uniformly impregnated not only to the portion of the brush surface but also to the pores facing inward. As such, the water-soluble lubricant is uniformly impregnated in the brush pores, so that the water-soluble lubricant acts uniformly over the entire sliding surface with the rotating body for a long time, and the mechanical resistance at the sliding surface is reduced to achieve good sliding performance. It is considered that the motor efficiency can be improved, the long life, the temperature, the sliding noise, and the commutator wear can be reduced. Here, if the impregnation amount of the water-soluble lubricant to the brush is less than 0.2% by weight, the effect of the water-soluble lubricant is not expressed, and if it exceeds 10% by weight, the efficiency of the motor is reduced. If the impregnation amount in the brush of the water-soluble lubricant is 0.2 to 3% by weight, an equivalent effect is obtained even if the content is reduced, so it is economical and preferable.

The water-soluble lubricant is a substance having water-soluble lubricating performance, and the preferred water-soluble lubricant applied to the electromechanical carbon brush of the present invention is polyethylene glycol or its derivatives, polyvinyl alcohol, polyvinylpyrrolidone, water-soluble silicone oil or Mixtures thereof. Examples of the polyethylene glycol derivatives include polyethylene glycol esters and polyethylene glycol ethers.

Moreover, among these water-soluble lubricants, water-soluble silicone oil has high high temperature stability, and is more preferable.

The electromechanical carbon brush of the present invention may be a fluorine-modified silicone oil in place of the water-soluble lubricant as a substance contained in the electromechanical carbon brush. In this case, it is preferable to make content of a fluorine modified silicone oil into 0.2 to 3 weight% with respect to a brush base material.

This configuration provides an electromechanical carbon brush capable of imparting high efficiency, long life, reduction of temperature, suppression of sliding sound, and reduction of commutator wear for a motor, thereby achieving the above object.

Fluorine-modified silicone oil has a small surface tension with the surface of the brush and easily penetrates into the fine pores by capillary action, so that it can be contained in the brush by impregnation. Therefore, the fluorine-modified silicone oil can be impregnated in the fine pores of the brush, and also uniformly impregnated not only the pores on the surface of the brush but also the pores inside. In this way, the fluorine-modified silicone oil is uniformly impregnated in the brush pores, so that the fluorine-modified silicone oil uniformly acts on the entire sliding surface with the rotating body for a long time, and the mechanical resistance at the sliding surface is reduced to provide good results. It is thought that the sliding efficiency is achieved to improve the efficiency of the motor. Here, if the impregnation amount of the fluorine-modified silicone oil in the brush is less than 0.2% by weight, the effect of the fluorine-modified silicone oil is not expressed, and if it exceeds 3% by weight, the efficiency of the motor is reduced.

In the electromechanical carbon brush of the present invention, the electromechanical carbon brush may be a material containing a water-soluble lubricant and a metal compound instead of the material. In this case, it is preferable that the content of the water-soluble lubricant is 0.2 to 10% by weight with respect to the brush base material, and the content of the metal compound is 0.05 to 10% by weight with respect to the brush base material. Since the effect of is obtained, it is economical and preferable.

In this configuration, the water-soluble lubricant and the metal compound are uniformly impregnated in the fine pores on the surface and inside of the brush as in the above configuration, further reducing the wear of the brush or commutator, lowering the temperature and sliding sound, The efficiency is considered to further improve.

Here, when the impregnation amount of the water-soluble lubricant and the metal compound in the brush deviates from the above range, the effect of improving the efficiency of the motor by these substances is not exhibited.

Moreover, in the electromechanical carbon brush of this invention, it is preferable that a binder consists of synthetic resins.

Resin bond-based brushes, such binders are made of synthetic resin, tend to have fine pores, but the above-described objects can be achieved by uniformly impregnating a water-soluble lubricant, a fluorine-modified silicone oil, a water-soluble lubricant, and a metal compound with such a brush.

In the electromechanical carbon brush of the present invention, the binder may be a carbide of synthetic resin or a carbide of pitch. As a specific example in this case, an epoxy resin, a phenol resin, a polyester resin, a vinyl ester resin, a furan resin, a polyamide resin, or a mixture thereof is illustrated as a synthetic resin. In addition, a pitch is illustrated as a coal pitch, a petroleum pitch, or a mixture thereof.

In the electromechanical carbon brush of the present invention, an electroconductive metal film is formed on at least one portion of the surface of the carbon brush except for the surface in contact with the conductive rotating body of the electromechanical carbon brush.

By using the brush in which the metal film is formed in this way, the efficiency with respect to a motor can be improved further.

1 is a perspective view showing a schematic configuration of a motor using a brush according to an embodiment of the present invention.

2 is a view showing the chemical structure of the water-soluble silicone oil according to the embodiment of the present invention.

3 is a view showing the chemical structure of the fluorine-modified silicone oil according to the embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

1 shows a schematic configuration of a motor using a brush according to an embodiment of the present invention.

The brush 1 is in contact with the rotating body 2, which is the commutator of the motor, and the lower surface 1a of the brush 1, and slides therein.

The brush 1 is based on the raw material which consists of aggregate and binder which contain carbon as at least one component. This substrate has pores as described above, and in the present embodiment, the pores of the brush substrate are impregnated with a water-soluble lubricant, a fluorine-modified silicone oil, or a water-soluble lubricant and a metal compound together.

The pores of the brush 1 may be, for example, a brush base material having a small pore radius of 1 µm or less, which is obtained by the mercury porosimetry.

Examples of the base material of the brush 1 include a carbon graphite brush called CG (Carbon Graphite), an electrographite brush called EG (Electric Graphite), a resin bond brush made of a synthetic resin in which the binder is not carbonized, copper powder, iron powder, Metal brush etc. which used metal powder, such as silver powder, as a part of aggregate can be used, Especially resin-bond brush is preferable.

The manufacturing method of this example bond type brush base material is demonstrated below.

First, these aggregates and a binder are kneaded with a compounding ratio of about 10-40 weight part of binder with respect to 100 weight part of aggregates.

As this aggregate, artificial graphite, natural graphite, expanded graphite, etc. can be used. Among these, artificial graphite, in which the crystallinity of graphite is not particularly developed, or a structure in which natural graphite and artificial graphite are blended is preferable.

On the other hand, as the binder, synthetic resin may be used, and either of thermosetting synthetic resin or thermoplastic synthetic resin may be used, or a mixture thereof may be used. As an especially preferable synthetic resin, an epoxy resin, a phenol resin, a polyester resin, a vinyl ester resin, a furan resin, a polyamide resin, and a polyimide resin are illustrated.

In addition, when kneading | mixing, you may add appropriate amounts of organic solvents, such as alcohol and acetone, as needed. Moreover, you may add an additive, for example, a solid lubricant and a film | membrane modifier to a part of aggregate as needed. For example, you may add solid lubricants, such as molybdenum disulfide and tungsten disulfide, and film modifiers, such as alumina, a silica, and a silicon carbide.

Next, the kneaded mass is pulverized and adjusted to powder for molding. Thereafter, the powder is shaped into a brush base material. The resin is cured by applying a heat treatment to the molded body at a temperature at which the resin is cured (generally, 100 to 300 ° C).

In addition, the brush 1 may form an electroconductive metal film on the side surface 1b except the lower surface 1a of the brush 1 and the front surface or one portion of the upper surface 1a in the step of brush base material. Nickel, copper, and silver are mentioned as a material of this film. In addition, although the thickness of this film is about 3-100 micrometers, it is not limited to this.

The metal film can be formed by a known method such as electroplating or electroless plating.

As a method of incorporating a water-soluble lubricant, a fluorine-modified silicone oil, or a water-soluble lubricant and a metal compound together in a brush, a method of mixing them with an aggregate or a binder during the manufacture of the brush, or impregnating them with a brush substrate prepared in advance It is possible to employ a method to make it.

Next, the structure which impregnates a more preferable water-soluble silicone oil among a water-soluble lubricant to a brush base material is demonstrated.

2 shows the structural formula of water-soluble silicone.

In this water-soluble silicone oil, one of the methyl groups bonded to the main chain of Si0 is replaced with a functional group to which an alkyl group and a polyalkylene oxide are connected. This silicone oil changes average molecular weight by the value of x and y (natural number) of FIG. 2, and a dynamic viscosity also changes with it. In this embodiment, it is preferable to have a kinematic viscosity of 10-200000 mm <2> / s (20 degreeC). Moreover, it is more preferable to use the water-soluble silicone oil which has a kinematic viscosity of 10-1000 mm <2> / s.

In order to impregnate the water-soluble silicone oil into a brush base material, first, the aqueous solution of the water-soluble silicone oil (silicone oil aqueous solution) shown in FIG. 2 is adjusted. Since the water-soluble silicone oil and water are easily mixed with each other, the silicone oil aqueous solution can be adjusted by a simple operation of stirring by hand using a stirring rod. The quantity of the water-soluble silicone oil in aqueous solution is suitably determined according to the target impregnation rate, impregnation conditions, the kind of selected base material, etc.

The adjusted silicone oil aqueous solution penetrates into the fine pores inside the capillary phenomenon and is impregnated uniformly in the pores of the brush base material. Therefore, impregnation can be performed simply by immersing a brush base material in silicone oil aqueous solution. However, you may use together the vacuum degassing and pressurization operation known as a general impregnation method.

The temperature of the silicone oil aqueous solution can be performed at room temperature of about 20 to 30 ° C. As needed, you may impregnate at the high temperature of 60-80 degreeC. Moreover, although immersion time is suitably determined according to conditions, such as the viscosity of a silicone oil aqueous solution, temperature, a brush base material, it is about 10 to 60 minutes, for example.

After immersing the brush for a certain time, the brush is taken out and dried at a temperature of 100 ° C. or more to remove moisture from the silicone oil aqueous solution impregnated with the brush. When the weight of the brush by drying becomes a certain amount, the removal of water is considered to have reached the end point and the drying is finished. The weight of the water-soluble silicone oil left on the brush substrate is the impregnated weight. In this embodiment, the weight of the water-soluble silicone oil impregnated is 0.2 to 10 weight% with respect to a brush base material.

In this way, the lead wires 3 and the like are suitably provided in the brush impregnated with the water-soluble silicone oil.

Next, the structure which impregnates a brush base material with a fluorine modified silicone oil is demonstrated.

3 shows the structural formula of the fluorine-modified silicone oil.

In this fluorine-modified silicone oil, one of the methyl groups bonded to the main chain made of SiO is substituted with a functional group to which (CH ₂ ) ₂ and CF ₃ are linked. This silicone oil changes the average molecular weight by the value of x (natural number) in Fig. 3, and the dynamic viscosity also changes accordingly. In this embodiment, it is preferable to have a kinematic viscosity of 10-200000 mm <2> / s (20 degreeC). Moreover, it is more preferable to use the fluorine modified silicone oil which has a kinematic viscosity of 10-1000 mm <2> / s.

Fluorine-modified silicone oil has a small surface tension with the brush surface, penetrates into the fine pores by capillary action, and is impregnated uniformly in the pores of the brush base material. Therefore, impregnation can be performed simply by immersing in a brush base material in fluorine modified silicone oil. However, you may use together the vacuum degassing and pressurization operation known as a general impregnation method.

And the temperature of a fluorine modified silicone oil can be performed at room temperature about 20-30 degreeC. As needed, you may impregnate at the high temperature of 60-80 degreeC. The immersion time is appropriately determined according to the conditions of the viscosity, temperature, brush base material and the like of the fluorine-modified silicone oil, but is about 10 to 60 minutes, for example.

After the brush has been immersed for a certain period of time, take out the brush and wipe off the fluorine-modified silicone oil attached to the brush surface with a soft cloth or remove it. The weight of the fluorine-modified silicone oil left on the brush base material is the impregnated weight.

In this embodiment, the weight of the impregnated fluorine-modified silicone oil is made 0.2 to 3 weight% with respect to a brush base material.

Thus, the lead wire 3 etc. are suitably provided in the brush impregnated with fluorine modified silicone oil.

Moreover, the case where a brush base material is impregnated with the mixture of a water-soluble lubricant and a metal compound is demonstrated.

This metal compound is a metal compound soluble in water or an organic solvent, Preferably it is a metal complex compound, More preferably, it is a chelate compound. The metal species of the metal compound is a metal of Groups 3 to 14 and 3 to 5 cycles in the long-period periodic table, preferably Al, Ti, Fe, Ni, Cu, Zn, Ag, Sn, and more. Preferably they are Fe, Cu, Zn, Ag.

The metal compound used in the present embodiment may be either ionic or covalent, and may be inorganic salts such as sulfates, nitrates, and hydrochlorides of the metal species, acetates, oxalates, benzoates, and benzene sulfonic acids of the metal species. Organic salts such as salts and metal complex compounds and chelate compounds in which the metal species are the central atoms are exemplified, but are not particularly limited and commercially available ones can be used. Ligands of complex or chelate compounds include ethylenediamine (en), diethylenetriamine (dien), triethylenetetramine (trien), ethylenediamine tetraacetic acid (edta), bipyridine (bpy) and terpyridine (terpy). It is preferable that they are ketone compounds, such as an amine compound, acetylacetone (acac), and oxime compounds, such as dimethylglyoxime (dmg).

In this embodiment, it is preferable that the mixture of a water-soluble lubricant and a metal compound has a kinematic viscosity of 10-200000 mm <2> / s (20 degreeC). In addition, it is more preferable to use a mixture of a water-soluble lubricant and a metal compound having a kinematic viscosity of 10 to 1000 mm 2 / s.

Like the above embodiment, the mixture of the water-soluble lubricant and the metal compound also has a small surface tension, penetrates into the fine pores by capillary action, and is uniformly impregnated in the pores of the brush base material. Therefore, impregnation can be performed only by immersing a brush base material in the mixture of a water-soluble lubricant and a metal compound. However, you may use together the vacuum degassing and pressurization operation known as a general impregnation method.

The mixture of the water-soluble lubricant and the metal compound can be impregnated at a room temperature of about 20 ° C to 30 ° C, but more preferably, is impregnated at a high temperature of 40 ° C to 60 ° C. Moreover, although immersion time is suitably determined according to conditions, such as the viscosity of a mixture of a water-soluble lubricant and a metal compound, temperature, a brush base material, etc., it is about 10 to 60 minutes, for example.

After immersing the brush for some time, the brush is dried at 100 ° C. The weight of the mixture of the water-soluble lubricant and the metal compound left on the brush base material is the impregnated weight.

In this case, content of a water-soluble lubricant is 0.2 to 10 weight% with respect to a brush base material, and content of a metal compound is 0.05 to 10 weight% with respect to a brush base material.

In this configuration, synergistic effects are obtained by using two kinds of materials, water-soluble lubricants and metal compounds as the material to be impregnated, improving the efficiency of the motor, long life, reduction of temperature, suppression of sliding sound, and reduction of commutator wear. It is thought that this becomes remarkable.

Hereinafter, the present invention will be described in more detail with reference to Examples.

First, the resin base material brush base material used in each Example was produced as follows.

30 weight part of epoxy resin is mix | blended with respect to 100 weight part of artificial graphite powders (average particle diameter 100 micrometers, 5 weight% or less of ash), and predetermined time (30-120 minutes) at normal temperature so that an artificial graphite powder and resin may be mixed uniformly. Kneaded

This kneaded material was crushed to 40 mesh or less, and it was set as the molding powder for shape | molding with a brush. After shaping | molding this shaping | molding powder in the shape of a brush with a metal mold (dimensions: 5.5x6x25mm), the heat processing of 150 degreeC was added using the commercially available dryer, and the resin was hardened.

This brush base material had a bulk density of 1.45 g / cm 3 and resistivity of 700 µΩ · m. Cumulative pore volume of this brush base material was 212 dl / g, and average pore radius was 0.76 micrometer. In addition, porosity was calculated | required by the mercury porosimetry (using the mercury porosimetry FISONS Instrument company model MAPO 120 and PO 2000).

(Example 1)

In embodiment, the water-soluble silicone oil which has a chemical structure shown in FIG. 2 was impregnated to the pore of the resin base material brush base material produced as mentioned above. In addition, the kinematic viscosity in 20 degreeC of the used water-soluble silicone oil was 100 mm <2> / s.

In the impregnation step, the water-soluble silicone oil was dissolved in a predetermined amount of water to form a silicone oil aqueous solution, and the brush substrate was immersed in the aqueous solution for a predetermined time.

In order to manufacture several kinds of brushes having different rates of impregnation of the silicone oil into the brush base material, a silicone oil concentration of the silicone oil aqueous solution was adjusted to 1 to 80% by weight, and the impregnation rate was changed by the difference in the silicone oil concentration. Adjusted. In addition, the time which the brush base material is immersed in the silicone oil aqueous solution was set to the time when weight increase is almost saturated. The immersion time was also 15 to 30 minutes, depending on the concentration of the silicone oil. In addition, the temperature of the silicone oil aqueous solution was set to 60 degreeC in either case.

After the immersion operation was completed, the brush base material was taken out from the silicone oil aqueous solution, and then the brush impregnated with the silicone oil aqueous solution was placed in a drier maintained at 120 ° C, and only the moisture impregnated with the silicone oil was removed by drying.

As mentioned above, the water-soluble silicone oil impregnation brush (four types) of 0.2 weight%, 1.2 weight%, 2.7 weight%, and 4.0 weight% of impregnation rates, respectively was obtained. Incidentally, the impregnation rate (% by weight) is a percentage obtained by multiplying the value obtained by dividing the weight of the increase by impregnation by the weight of the brush before impregnation.

The efficiency of the motor when these four types of water-soluble silicone oil impregnation brush and a brush base material were used was calculated | required.

To measure the efficiency of the motor, first, after providing the lead wires to these brushes, the test motor was set to a spring pressure of 35 kPa. Under constant conditions, the suction power P (W) was measured for each brush. Moreover, about 1000W of electric power was input to the motor under the voltage of 100V and 60 mA. At this time, the rotation speed of the motor was about 32000 rpm.

The efficiency of the motor was calculated by the equation (1).

η = (P / I) × 100 (1)

Here, η is the motor efficiency (%), P is the suction work rate (W), and I is the input (W).

When the efficiency (η) of the motor obtained thereby is used with a brush that does not impregnate the water-soluble silicone oil, the test results of the efficiency of each motor when the four types of water-soluble silicone oil-impregnated brushes are used are shown in Table 1 below. Indicates.

 Impregnation rate of water-soluble silicone oil (wt%)  Motor efficiency η (%) 0 40.2 0.2 40.3 1.2 40.4 2.7 40.3 4.0 39.8

As shown in Table 1, when the impregnation rate is 1.2% by weight, the efficiency of the motor is 40.4%, which is 0.2% higher than the efficiency of the motor of the brush (impregnated brush) that does not impregnate water-soluble silicone oil. The value was shown. In addition, when the impregnation rate was 0.2% by weight and 2.7% by weight, the efficiency of the motor was 40.3%, and the value was 0.1% higher than the efficiency of the motor of the non-impregnation brush. Moreover, when an impregnation rate was 4.0 weight%, as shown in Table 1, it became a result to reduce the efficiency of a motor.

The improvement of the motor efficiency by 0.1 to 0.2% is judged to be a remarkable effect in the field of small motors used in vacuum cleaners and the like. Therefore, the improvement of the efficiency of such a motor has great significance and is evaluated as having high use value. In particular, in the situation where the input is restricted by the standard of the motor or the like, considering that the output cannot be increased by increasing the input, it is essential that a brush having a higher motor efficiency is required in this way.

Further, a copper film having a thickness of 10 µm was formed by copper electroless plating on the entire surface of the surrounding surface except for the part in contact with the rotating part of the brush of the brush base material produced in the present embodiment.

The same water-soluble silicone oil was impregnated into the brush base material which formed this copper film by the method of the said (this Example). As a result, the water-soluble silicone oil impregnation rate with respect to the brush base material which formed the copper film became the value about 20% lower than the said brush without a copper film. However, in the case of the brush base material on which the copper film was formed, the impregnation rate equivalent to that of the brush without the copper film was obtained by the method of lengthening the immersion time or changing the immersion temperature.

Such a brush contributes to the said effect by the effect of the film of electroconductive metal on the brush surface, ie, the temperature rise of a brush can be suppressed, and stable rectification can be maintained over a long term.

(Example 2)

In Example 2, first, the fluorine-modified silicone oil having the chemical structure shown in Fig. 3 was impregnated with the brush substrate prepared in Example 1. Here, the kinematic viscosity of the fluorine-modified silicone oil was 100 mm 2 / s.

Impregnation of the fluorine-modified silicone oil was performed by immersing the brush base material in the fluorine-modified silicone oil at a room temperature of 25 ° C. for a certain time. Then, the brush was taken out and the fluorine-modified silicone oil adhered to the brush surface was wiped off with a soft cloth or removed.

By varying the time to immerse the brush substrate in the fluorine-modified silicone oil, the brush of the same impregnation rate as in Example 1, that is, the impregnation rate of 0.2% by weight, 1.2% by weight, 2.7% by weight, 4.0% by weight of fluorine modified Silicone oil impregnation brush (four types) was obtained. In addition, the impregnation rate was calculated | required by the method similar to the case of Example 1.

The efficiency of the motor when these four types of fluorine-modified silicone oil impregnation brushes and a brush base material were used was calculated by the formula (1) as in Example 1.

Table 2 shows the test results of the efficiency (η) of each motor when the brush which does not impregnate the obtained fluorine modified silicone oil and four types of fluorine modified silicone oil impregnation brushes are used.

As shown in Table 2, when the impregnation rate is 0.2% by weight, the motor efficiency is 40.4%. When the impregnation rate is 1.2% by weight, the motor efficiency is 40.7%. When the impregnation rate is 1.2% by weight, the motor efficiency is 40.5%. Was%. That is, 0.2% to 0.5% higher than the efficiency of the motor 40.2% of the impregnated brush. In the case where the impregnation rate is 1.2% by weight, the efficiency of the motor is dramatically increased. Moreover, when an impregnation rate was 4.0 weight%, as shown in Table 2, it became a result to lower the efficiency of a motor.

(Example 3)

The brush base material produced in Example 1 was impregnated with a mixture of a water-soluble silicone oil having a chemical structure shown in FIG. 2 and a metal complex compound Cu (edta). Here, the kinematic viscosity of this water-soluble silicone oil and metal complex chemical was 100 mm 2 / s.

Impregnation of this water-soluble silicone oil and a metal compound was performed by immersing a brush base material in this mixture for 15 minutes at 50 degreeC liquid temperature. Then, after removing the brush base material from this mixture, the brush was placed in a drier maintained at 100 ° C. to remove the water impregnated with the water-soluble silicone oil and the metal compound.

Each brush which the impregnation rate of this water-soluble silicone oil and a metal compound shows in Table 3 was obtained. In addition, the impregnation rate was calculated | required by the method similar to the case of Example 1.

The efficiency (η) of the motor when these water-soluble silicone oils, a metal compound impregnation brush and a brush base material were used was calculated by the formula (1) as in Example 1. In addition, the amount of brush wear per 100 hours (mm / 100h), the temperature of the outer edge of the brush holder (° C), the sliding sound of the brush (using a sound level meter made by ONO SOKKI) and the amount of commutator wear per 100 hours were measured. The results are shown in Table 3.

To measure the efficiency of the motor, first, after providing the lead wires to these brushes, the test motor was set at a spring pressure of 41 kPa. Under constant conditions, the suction power P (W) was measured for each brush. Moreover, about 1550W of electric power was input into the motor under the voltage of 230V and 60 kV. At this time, the rotation speed of the motor was about 34000 rpm.

As shown in Table 3, in sample numbers (2) to (4) and (6) to (17), the efficiency of the motor was 41.4% to 41.9%, respectively, and the impregnated with the water-soluble silicone oil and the metal compound was not. It was 0.4-0.9% higher than the efficiency of 41.0% of the motor of the brush (impregnated brush), showing a remarkable effect. In addition, about the brush wear amount per 100 hours, in sample numbers (2)-(4), (6)-(17), it becomes a value of 3.8-7 (mm / 100h), and 10 (mm / 100h) of an impregnated brush. It is significantly reduced compared to). Moreover, about temperature, it suppressed below 100 degreeC. In addition, about the sliding sound, sample numbers (2)-(4), (6)-(17) became low compared with 110 kPa of an impregnation brush.

Regarding the amount of commutator wear per 100 hours, the sample numbers (2) to (4) and (6) to (17) are 0.04 to 0.08 (mm / 100h), and 0.12 (mm / 100h) of the impregnated brush. Compared with that, it was significantly reduced.

In an electric machine equipped with a motor such as an electric vacuum cleaner, when there is an input restriction due to the specification of the motor or the like, it is required to have high motor efficiency. The present invention can be used for the motor with it. In addition, the life of the brush is long, the sliding sound can be reduced, it is economically advantageous, it is possible to shorten the brush, it can contribute to the miniaturization of the motor.

Claims (8)

As an electromechanical carbon brush pressed against a conductive rotating body, The brush base material is a material comprising an aggregate and a binder containing carbon as at least one component, Water-soluble lubricant is contained in the electromechanical carbon brush, An electromechanical carbon brush, wherein the content of the water-soluble lubricant is 0.2 to 10% by weight based on the brush base material. The electromechanical carbon brush according to claim 1, wherein the water-soluble lubricant is any one of polyethylene glycol or a derivative thereof, polyvinyl alcohol, polyvinylpyrrolidone, water-soluble silicone oil, or a mixture thereof. As an electromechanical carbon brush pressed onto a conductive rotating body, The brush base material is a material comprising an aggregate and a binder containing carbon as at least one component, Fluorine-modified silicone oil is contained in the electromechanical carbon brush, An electromechanical carbon brush, wherein the content of the fluorine-modified silicone oil is 0.2 to 3% by weight based on the brush base material. The electromechanical carbon brush according to any one of claims 1 to 3, which contains a metal compound. 5. The electromechanical carbon brush according to claim 4, wherein the content of the metal compound is 0.05 to 10% by weight based on the brush base material. 6. The electromechanical carbon brush according to any one of claims 1 to 5, wherein the binder is made of a synthetic resin. 6. The electromechanical carbon brush according to any one of claims 1 to 5, wherein the binder is composed of a carbonized material of a synthetic resin or a carbonized material of a pitch. The electroconductive metal film according to any one of claims 1 to 7, wherein an electroconductive metal film is formed on at least one portion of the surface of the carbon brush except for the surface of the electromechanical carbon brush that contacts the conductive rotor. Electromechanical carbon brush, characterized in that.

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