JP3858038B2 - Carbon brush for electric machine - Google Patents

Description

  The present invention relates to a carbon brush for an electric machine, and more particularly, to a carbon brush for an electric machine used for a small motor.

  Electric motors are becoming smaller, larger capacity, and higher output. For example, a motor used in a vacuum cleaner is required to be smaller and have a strong suction force. For this reason, the outer diameter of the fan of the motor is reduced, and the motor is rotated at an ultra high speed (30,000 rpm or more). In such an ultra-high speed motor, normal electrical contact is maintained by maintaining a good sliding state between a carbon brush for an electric machine (hereinafter referred to as a brush) and a commutator which is a conductive rotating body. It has been regarded as an important issue to maintain.

  Conventionally, in view of such a problem, a so-called resin bond type brush in which graphite powder is bonded with a synthetic resin has been widely used. This resin-bonded brush is made slippery with graphite powder and has good seating properties with the resin, thereby ensuring normal electrical contact.

  Further, in a vacuum cleaner or the like, the brush current density can be increased by increasing the motor input in order to increase the suction force (suction power). However, in the case of such a method, in particular, a resin-bonded brush may cause a rectification failure due to an increase in brush temperature due to long-time use or an increase in wear of the brush.

Furthermore, the background of input restriction has to be taken into consideration, and there has been a further demand for a motor that can obtain a higher output for a given input.
Under such circumstances, there has been a strong demand for a brush that can ensure stable rectification and can provide high efficiency (output with respect to input) to the motor.

  As a countermeasure against such a problem, Patent Document 1 discloses a method of partially reducing the specific resistance of a brush by plating the brush surface with a metal such as copper. In this method, the apparent specific resistance of the brush is reduced, so that the temperature rise of the brush is suppressed, rectification is stabilized, brush wear is reduced, and higher motor efficiency can be obtained.

Patent Document 2 discloses a method for improving brush wear characteristics by impregnating brush oil with silicone oil. In this method, the slidability between the brush and the commutator is improved, so that the temperature rise of the brush is suppressed and the wear of the brush is reduced.
JP 2002-56944 A US Pat. No. 6,068,926

  In the techniques according to these publications, the wear of the brush is suppressed and the life of the brush is expected to be extended. However, in the method shown in Patent Document 1, although the rectification is stabilized and the brush temperature rise and the brush wear are reduced, the specific resistance is partially lowered by applying metal plating to the brush surface. There was a limit to improving efficiency. In other words, the efficiency of the motor and the life of the brush produced by the stabilization of rectification by the action of the metal plating applied around the brush are limited.

Further, in the method shown in Patent Document 2, the temperature rise and brush wear of the brush are reduced, but silicone oil is made into an emulsion and impregnated in the pores of the brush, so that the silicone oil is uniformly impregnated in the pores of the brush. It was difficult to do and unevenness had occurred. As a result, good slidability between the brush and the commutator cannot be ensured, and stable rectification may not be ensured.

  The present invention was devised in view of such a situation, and more stable commutation is ensured, and high efficiency, long life, temperature reduction, sliding noise suppression, and commutator wear reduction for a motor are obtained. It is an object to provide a carbon brush for an electric machine.

In order to solve the above problems, an electric machine carbon brush according to the present invention is an electric machine carbon brush pressed against a conductive rotating body, and includes an aggregate containing at least one carbon and a binder. The material is a brush base material, the water-soluble silicone oil is impregnated in the carbon brush for electric machine, and the impregnation amount of the water-soluble silicone oil is 0.2 to 10% by weight with respect to the brush base material. Characterized by

  The brush base material composed of the aggregate and the binder has void portions called “pores”. Here, impregnation means that a water-soluble lubricant is present in the pores in the substance. means.

  The size and volume of the existing pores vary depending on the type of brush, manufacturing method, manufacturing conditions, and the like. The pores exist in the entire brush, and there are open pores connected from the brush surface to the inside and closed pores isolated in the brush. Hereinafter, the term “pores” simply means open pores.

Therefore, since the water-soluble silicone oil is an aqueous solution, the pores of the brush can be impregnated with the water-soluble silicone oil while maintaining the molecular level. Furthermore, the water-soluble silicone oil has a surface-active action, and the surface tension is lowered, so that the water-soluble silicone oil easily penetrates into fine pores by capillary action. Therefore, the water-soluble silicone oil can be impregnated even in the fine pores of the brush, and the pores not only on the brush surface but also toward the inside are uniformly impregnated. As described above, the water-soluble silicone oil is uniformly impregnated in the brush pores, so that the water-soluble silicone oil acts uniformly on the entire sliding surface with the rotating body for a long time and slides. By reducing the mechanical resistance on the surface and achieving good slidability, it is thought that motor efficiency can be improved, long life, temperature can be reduced, sliding noise can be suppressed, and commutator wear can be reduced. . Here, if the impregnation amount of the water-soluble silicone oil into the brush is less than 0.2% by weight, the effect of the water-soluble silicone oil is not exhibited, and if it is 10% by weight or more, the efficiency of the motor is lowered. When the impregnation amount of the water-soluble silicone oil with respect to the brush is 0.2 to 3% by weight, the same effect can be obtained even if the content is reduced.

Further, the water-soluble silicone oil is excellent in that it has high temperature stability.

Moreover, the carbon brush for electric machines of this invention is good also as a substance contained in the carbon brush for electric machines as a fluorine modified silicone oil instead of the said water-soluble silicone oil . In this case, the content of the fluorine-modified silicone oil is preferable to be 0.2 to 3% by weight relative to the brush base material.

Since the fluorine-modified silicone oil has a small surface tension with the brush surface and easily penetrates into fine pores by capillary action, it can be contained in the brush by impregnation. Therefore, the fluorine-modified silicone oil can be impregnated even in the fine pores of the brush, and is uniformly impregnated not only in the pores of the brush surface but also in the internal pores. In this way, the fluorine-modified silicone oil is uniformly impregnated in the brush pores, so that the fluorine-modified silicone oil acts uniformly on the entire sliding surface with the rotating body for a long period of time. It is considered that the efficiency with respect to the motor is improved by reducing the mechanical resistance on the surface and achieving good slidability. Here, if the content of the fluorine-modified silicone oil with respect to the brush is less than 0.2% by weight, the effect of the fluorine-modified silicone oil is not exhibited, and if it exceeds 3% by weight, the efficiency of the motor is lowered.

Furthermore, in the carbon brush for electric machines of this invention, it may be the structure containing a water-soluble silicone oil and a metal compound instead of the said substance as a substance contained in the carbon brush for electric machines. In this case, the impregnation amount of the water-soluble silicone oil 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. In the case of 0.1 to 4% by weight, the same effect can be obtained even if the content is reduced, which is more preferable.

In this configuration, the water-soluble silicone oil and the metal compound are uniformly impregnated on the surface of the brush and the fine pores inside the brush as in the above configuration, thereby further reducing the wear of the brush and the commutator, and the temperature and sliding. It is considered that the dynamic noise is lowered and the efficiency of the motor is further improved.

Here, when content with respect to the brush of water-soluble silicone oil and a metal compound deviates from the said range, the improvement effect of the efficiency of the motor by these substances will not be expressed.

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

Resin-bonded brushes of which the binder is made of synthetic resin tend to have fine pores. However, water-soluble silicone oil , fluorine-modified silicone oil, water-soluble silicone oil, and metal are also used for such brushes. The above object is achieved by uniformly impregnating the compound.

  In the carbon brush for electric machines of the present invention, the binder may be a carbonized product of synthetic resin or a carbonized product of pitch. Specific examples of the synthetic resin include an epoxy resin, a phenol resin, a polyester resin, a vinyl ester resin, a furan resin, a polyamide resin, a polyimide resin, or a mixture thereof. Examples of the pitch include coal-based pitch, petroleum-based pitch, or a mixture thereof.

  Further, in the carbon brush for electric machine of the present invention, an electrically conductive metal film is formed on at least a part of the surface of the carbon brush excluding the surface in contact with the conductive rotating body of the carbon brush for electric machine. Can be used.

  According to the configuration of the present invention, a carbon brush for an electric machine capable of imparting high efficiency, long life, reduction of temperature, suppression of sliding noise, and reduction of commutator wear to a motor is provided, and the above object is achieved.

  Moreover, the efficiency with respect to a motor can further be improved by using the brush in which the metal membrane | film | coat is formed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 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 that is a commutator of the motor and the lower surface 1a of the brush 1 and slides at that portion.

  The brush 1 has a base material made of an aggregate containing carbon as at least one component and a binder. This substrate has pores as described above, and in this embodiment, a water-soluble lubricant, fluorine-modified silicone oil, or a water-soluble lubricant and a metal compound are contained in the pores of the brush substrate. Impregnate both.

  The pores of the brush 1 may be, for example, a brush base material having a small pore radius with an average pore radius determined by a mercury intrusion method of 1 μm or less.

  As a base material of the brush 1, a carbon graphite brush called CG (Carbon Graphite) system, an electric graphite brush called EG (Electric Graphite) system, and a resin bond system that is a synthetic resin whose binder is not carbonized A metal brush using metal powder such as a brush, copper powder, iron powder, silver powder or the like as part of the aggregate can be used, and a resin bond brush is particularly preferable.

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

  First, these aggregates and a binder are knead | mixed by making 10-40 weight part of binder into a general compounding ratio with respect to 100 weight part of aggregates.

  As this aggregate, artificial graphite, natural graphite, expanded graphite and the like can be used. Of these, artificial graphite in which the crystallinity of graphite is not so developed, or a configuration in which natural graphite and artificial graphite are blended is preferable.

  On the other hand, a synthetic resin is used as the binder, and either a thermosetting synthetic resin or a thermoplastic synthetic resin may be used, or a mixture thereof may be used. Particularly suitable synthetic resins include epoxy resins, phenol resins, polyester resins, vinyl ester resins, furan resins, polyamide resins, and polyimide resins.

  When kneading, an appropriate amount of an organic solvent such as alcohols or acetone may be added as necessary. Moreover, you may add an additive, for example, a solid lubricant, and a film | membrane regulator, to some aggregates as needed. For example, a solid lubricant such as molybdenum disulfide or tungsten disulfide, or a film modifier such as alumina, silica, or silicon carbide may be added.

  Next, the kneaded mass is pulverized to prepare a powder for molding. Thereafter, the powder is formed into a brush base material shape. And it heat-processes under the temperature (generally 100-300 degreeC) which resin hardens | cures to a molded object, and resin is hardened.

  Moreover, the brush 1 may form an electrically conductive metal film on the entire surface or a part of the side surface 1b and the upper surface 1a excluding the lower surface 1a of the brush 1 at the stage of the brush substrate. Examples of the material of the coating include nickel, copper, and silver. Moreover, although the thickness of this film | membrane is about 3-100 micrometers in general, it is not limited to this.

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

  As a method of incorporating a water-soluble lubricant, fluorine-modified silicone oil, or a water-soluble lubricant and a metal compound together in the brush, a method of mixing these together with an aggregate or a binder in the course of manufacturing the brush, A method of impregnating them with the brush base material can be employed.

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

  FIG. 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 composed of SiO 2 is replaced with a functional group in which an alkyl group and a polyalkylene oxide are linked. In this silicone oil, the average molecular weight changes depending on the values of x and y (natural numbers) in FIG. 2, and the kinematic viscosity changes accordingly. In this embodiment, what has a kinematic viscosity of 10-20000 mm < ² > / s (20 degreeC) is preferable. It is more preferable to use a water-soluble silicone oil having a kinematic viscosity of 10 to 1000 mm ² / s.

  To impregnate the brush base material with the water-soluble silicone oil, first, an aqueous solution of the water-soluble silicone oil (silicone oil aqueous solution) shown in FIG. 2 is prepared. Since the water-soluble silicone oil and water are easily mixed, the aqueous silicone oil solution can be prepared by a simple operation such as stirring by hand using a stirring rod. The amount of water-soluble silicone oil in the aqueous solution is appropriately determined according to the intended impregnation rate, impregnation conditions, the type of substrate selected, and the like.

  The prepared aqueous silicone oil solution penetrates into the fine pores by capillary action to the inside, and is uniformly impregnated into the pores of the brush base material. Therefore, the impregnation can be performed by simply immersing the brush substrate in an aqueous silicone oil solution. However, vacuum degassing and pressurizing operations known as general impregnation methods may be used in combination.

  The temperature of the silicone oil aqueous solution can be performed at room temperature of about 20 to 30 ° C. If necessary, the impregnation may be performed at a high temperature of 60 to 80 ° C. In addition, the immersion time is appropriately determined depending on conditions such as the viscosity of the aqueous silicone oil solution, the temperature, and the brush base material, and is, for example, about 10 to 60 minutes.

After dipping the brush for a certain period of time, the brush is taken out and dried at a temperature of 100 ° C. or higher to remove moisture from the aqueous silicone oil solution impregnated in the brush. When the weight of the brush by drying reaches a constant weight, it is considered that the removal of moisture has 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 impregnated water-soluble silicone oil is 0.2 to 10% by weight with respect to the brush base material.

  Thus, the lead wire 3 etc. are suitably attached to the brush impregnated with the water-soluble silicone oil.

  Next, a configuration in which the brush base material is impregnated with fluorine-modified silicone oil will be described. FIG. 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 ₂ is replaced with a functional group in which (CH ₂ ) ₂ and CF ₃ are linked. The average molecular weight of this silicone oil changes depending on the value of x (natural number) in FIG. 3, and the kinematic viscosity changes accordingly. In this embodiment, what has a kinematic viscosity of 10-20000 mm < ² > / s (20 degreeC) is preferable. It is more preferable to use a fluorine-modified silicone oil having a kinematic viscosity of 10 to 1000 mm ² / s.

The fluorine-modified silicone oil has a small surface tension with the brush surface, 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 by simply immersing the brush base material in fluorine-modified silicone oil. However, vacuum degassing and pressurizing operations known as general impregnation methods may be used in combination.

  And the temperature of fluorine-modified silicone oil can be performed at room temperature of about 20-30 degreeC. If necessary, the impregnation may be performed at a high temperature of 60 to 80 ° C. In addition, the immersion time is appropriately determined depending on conditions such as the viscosity of the fluorine-modified silicone oil, the temperature, the brush base material, etc., and is, for example, about 10 to 60 minutes.

  After immersing the brush for a certain time, the brush is taken out and the fluorine-modified silicone oil adhering to the brush surface is removed by wiping with a soft cloth. The weight of the fluorine-modified silicone oil left on the brush substrate is the impregnated weight.

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

  Thus, the lead wire 3 etc. are suitably attached to the brush impregnated with the fluorine-modified silicone oil.

  Furthermore, the case where a brush base material is impregnated with a mixture of a water-soluble lubricant and a metal compound will be described.

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

  The metal compound used in the present embodiment may be an ionic bond or a covalent bond, and may be an inorganic salt such as sulfate, nitrate, or hydrochloride of the above metal species, acetate of the above metal species, or oxalic acid. Examples thereof include organic acid salts such as salts, benzoates, and benzenesulfonates, and metal complex compounds and chelate compounds in which the above metal species are the central atom, but are not particularly limited, and commercially available products can be used. The ligand of the complex compound or the chelate compound is an amine compound such as ethylenediamine (en), diethylenetriamine (dien), triethylenetetramine (trien), ethylenediaminetetraacetic acid (edta), piperidine (bpy), terpyridine (terpy), A ketone compound such as acetylacetone (acac) or an oxime compound such as dimethylglyoxime (dmg) is preferred.

In the present embodiment, the mixture of the water-soluble lubricant and the metal compound preferably has a kinematic viscosity of 10 to 20000 mm ² / s (20 ° C.). It is more preferable to use a mixture of a water-soluble lubricant having a kinematic viscosity of 10 to 1000 mm ² / s and a metal compound.

  Similarly to the above embodiment, the mixture of the water-soluble lubricant and the metal compound has a small surface tension and penetrates into the fine pores to the inside by capillary action and is uniformly impregnated in the pores of the brush base material. Therefore, impregnation can be performed by simply immersing the brush substrate in a mixture of a water-soluble lubricant and a metal compound. However, vacuum degassing and pressurizing operations known as general impregnation methods may be used in combination.

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

  After dipping the brush for a certain 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 substrate is the impregnated weight.

  In this case, 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.

  In this configuration, a synergistic effect is achieved by using two types of materials, water-soluble lubricant and metal compound, as impregnated materials, improving motor efficiency, long life, reducing temperature, and suppressing sliding noise. It is considered that the reduction of commutator wear becomes significant.

  Hereinafter, the present invention will be described more specifically with reference to examples.

  First, a resin-bonded brush base material used in each example was prepared as follows.

  30 parts by weight of epoxy resin is blended with 100 parts by weight of artificial graphite powder (average particle size 100 μm, ash content 5% by weight or less), and at a normal temperature, the artificial graphite powder and the resin are uniformly mixed. Kneading was carried out for a time (30 to 120 minutes).

  This kneaded product was pulverized to 40 mesh or less to obtain a molding powder for molding into a brush. The molding powder was molded into a brush shape with a mold (size: 5.5 × 6 × 25 mm), and then heat-treated at 150 ° C. using a commercially available dryer to cure the resin.

This brush base material had a bulk density of 1.45 g / cm ³ and a resistivity of 700 μΩ · m. The brush substrate had a cumulative pore volume of 212 mm ³ / g and an average pore radius of 0.76 μm. In addition, the porosity was calculated | required by the mercury intrusion method (The mercury porosimeter FISONS Instrument company make, model MAPO120 and PO2000 was used).
[Example 1]
In the embodiment, the water-soluble silicone oil having the chemical structure shown in FIG. 2 was impregnated into the pores of the resin-bonded brush base material produced as described above. The water-soluble silicone oil used had a kinematic viscosity at 20 ° C. of 100 mm ² / s.

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

  In order to produce several types of brushes with different rates of silicone oil impregnation into the brush base material, the silicone oil concentration of the silicone oil aqueous solution was adjusted to 1 to 80% by weight. Adjusted. Moreover, the time for immersing the brush base material in the silicone oil aqueous solution was set at the time when the weight increase was almost saturated. The immersion time was 15 to 30 minutes, although it varied depending on the concentration of the silicone oil. The temperature of the silicone oil aqueous solution was set to 60 ° C. in all cases.

After this dipping operation is completed, after removing the brush base material from the silicone oil aqueous solution,
The brush impregnated with the aqueous silicone oil solution was placed in a dryer maintained at 120 ° C., and only the water impregnated with the silicone oil was removed by drying.

  Thus, water-soluble silicone oil-impregnated brushes (4 types) having an impregnation rate of 0.2% by weight, 1.2% by weight, 2.7% by weight, and 4.0% by weight were obtained. The impregnation rate (% by weight) is expressed as a percentage by multiplying the value obtained by dividing the weight of the increase due to impregnation by the weight of the brush before impregnation by 100.

  The efficiency of the motor when these four types of water-soluble silicone oil-impregnated brushes and brush base materials were used was determined.

  To measure the motor efficiency, first, lead wires were attached to these brushes, and then set to a test motor with a spring pressure of 35 kPa. Suction power P (W) was measured for each brush under certain conditions. In addition, about 1000 W of electric power was input into the motor under the voltage of 100V and 60 Hz. At this time, the rotation speed of the motor was about 32000 rpm.

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

η = (P / I) x 100 (1)
Here, η is the motor efficiency (%), P is the suction power (W), and I is the input (W).

  The motor efficiency (η) thus obtained is tested for the efficiency of each motor when the above-mentioned four types of water-soluble silicone oil-impregnated brushes are used when a brush not impregnated with water-soluble silicone oil is used. The results are shown in Table 1.

表１に示すように、含浸率が１．２重量％の場合は、モータの効率が４０．４％であり、水溶性シリコーンオイルを含浸していないブラシ（無含浸ブラシ）のモータの効率４０．２％に対して０．２％高い値を示した。また、含浸率が０．２重量％及び２．７重量％の場合には、モータの効率が４０．３％であり、無含浸ブラシのモータの効率より０．１％高い値を示した。なお、含浸率が４．０重量％の場合は、表１に示すようにモータの効率を下げてしまう結果となった。

As shown in Table 1, when the impregnation ratio is 1.2% by weight, the motor efficiency is 40.4%, and the motor efficiency of a brush (non-impregnated brush) not impregnated with water-soluble silicone oil is 40. It was 0.2% higher than 2%. When the impregnation ratio was 0.2% by weight and 2.7% by weight, the motor efficiency was 40.3%, which was 0.1% higher than the efficiency of the non-impregnated brush motor. When the impregnation rate was 4.0% by weight, the motor efficiency was lowered as shown in Table 1.

  An improvement in the motor efficiency of 0.1 to 0.2% is judged as a significant effect in the field of small motors used in vacuum cleaners and the like. Therefore, the improvement in the efficiency of such a motor is evaluated as having great significance and high utility value. In particular, in a situation where the input is restricted by the motor standard, etc., considering that the output cannot be increased by increasing the input, a brush with higher motor efficiency is thus obtained. It is essential to be required.

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

  The same base material was impregnated with the same water-soluble silicone oil by the method described above (this example). As a result, the water-soluble silicone oil impregnation rate with respect to the brush base material on which the copper film was formed was about 20% lower than that of the brush without the copper film. However, in the case of a brush base material on which a copper film is formed, an impregnation rate equivalent to that for a brush without a copper film could be obtained by increasing the immersion time or changing the immersion temperature. .

Such a brush contributes to the above effect in that the effect of the electrically conductive metal film on the brush surface, that is, the temperature rise of the brush can be suppressed and stable rectification can be maintained over a long period of time.
[Example 2]
In Example 2, first, the brush base material produced in Example 1 was impregnated with fluorine-modified silicone oil having the chemical structure shown in FIG. Here, the kinematic viscosity of the fluorine-modified silicone oil was 100 mm ² / s.

  The impregnation with the fluorine-modified silicone oil was performed by immersing the brush base material in the fluorine-modified silicone oil for a predetermined time at a room temperature of 25 ° C. Thereafter, the brush was taken out and the fluorine-modified silicone oil adhering to the brush surface was removed by wiping with a soft cloth.

  By changing the time for immersing the brush base material in the fluorine-modified silicone oil, the brushes having the same impregnation rate as in Example 1, that is, the impregnation rates were 0.2 wt%, 1.2 wt%, and 2.7 wt%, respectively. % And 4.0% by weight of fluorine-modified silicone oil impregnated brushes (4 types). The impregnation rate was determined in the same manner as in Example 1.

  The efficiency of the motor when these four types of fluorine-modified silicone oil-impregnated brushes and brush base materials 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 not impregnated with the fluorine-modified silicone oil thus obtained and four types of fluorine-modified silicone oil-impregnated brushes were used.

表２に示すように、含浸率が０．２重量％の場合にはモータの効率が４０．４％、含浸率が１．２重量％の場合にはモータの効率が４０．７％、２．７重量％の場合にはモータの効率が４０．５％であった。つまり、無含浸ブラシのモータの効率４０．２％より０．２％〜０．５％高い値を示した。含浸率が１．２重量％の場合にはモータの効率がこのように飛躍的に高くなった。なお、含浸率が４．０重量％の場合は、表２に示すようにモータの効率を下げてしまう結果となった。
［実施例３］
実施例１で作製したブラシ基材に対して、図２に示す化学構造を有する水溶性シリコーンオイルと金属錯化合物Ｃｕ（ｅｄｔａ）の混合物に含浸した。ここで、この水溶性シリコーンオイルおよび金属錯化合物の動粘度は、１００ｍｍ² ／ｓであった。

As shown in Table 2, the motor efficiency is 40.4% when the impregnation rate is 0.2% by weight, and the motor efficiency is 40.7% when the impregnation rate is 1.2% by weight. In the case of 0.7% by weight, the motor efficiency was 40.5%. That is, the efficiency of the non-impregnated brush motor was 0.2% to 0.5% higher than the efficiency of 40.2%. When the impregnation rate was 1.2% by weight, the efficiency of the motor was thus dramatically increased. When the impregnation rate was 4.0% by weight, the motor efficiency was lowered as shown in Table 2.
[Example 3]
The brush base material produced in Example 1 was impregnated with a mixture of water-soluble silicone oil having a chemical structure shown in FIG. 2 and a metal complex compound Cu (edta). Here, the kinematic viscosity of the water-soluble silicone oil and the metal complex compound was 100 mm ² / s.

  The impregnation of the water-soluble silicone oil and the metal compound was performed by immersing the brush base material in this mixture for 15 minutes at a liquid temperature of 50 ° C. Then, after taking out the brush base material from this mixture, this brush was put into a drier kept at 100 ° C. to remove moisture impregnated with the water-soluble silicone oil and the metal compound.

  The brushes with impregnation rates of the water-soluble silicone oil and metal compound shown in Table 3 were obtained. The impregnation rate was determined in the same manner as in Example 1.

  The efficiency (η) of the motor when these water-soluble silicone oil, metal compound-impregnated brush and brush base material were used was calculated by the formula (1) as in Example 1. In addition, the amount of wear of the brush per 100 hours (mm / 100h), the temperature at the tip of the outer periphery of the brush holder (° C), the sliding sound of the brush (dB) (using a sound level meter manufactured by ONOSOKKI), and rectification per 100 hours Table 3 shows the results of measuring the child wear amount.

  To measure the motor efficiency, first, lead wires were attached to these brushes, and then set to a test motor with a spring pressure of 41 kPa. Suction power P (W) was measured for each brush under certain conditions. In addition, about 1550W of electric power was input into the motor under the voltage 230V and 60Hz. 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 motor efficiency is 41.4% to 41.9%, respectively. The impregnated brush (non-impregnated brush) showed a dramatic effect with a value 0.4 to 0.9% higher than the motor efficiency of 41.0%. The brush wear amount per 100 hours is 3.8 to 7 (mm / 100h) in the sample numbers (2) to (4) and (6) to (17). Compared to (mm / 100h), it was drastically reduced. Moreover, about temperature, it was restrained to 100 degrees C or less. Furthermore, the sliding noise was lower in sample numbers (2) to (4) and (6) to (17) than 110 dB of the non-impregnated brush.

  The amount of commutator wear per 100 hours is 0.04 to 0.08 (mm / 100h) for sample numbers (2) to (4) and (6) to (17). Compared to 0.12 (mm / 100h), it was drastically reduced.

  An electric machine equipped with a motor such as a vacuum cleaner is required to have high motor efficiency especially when there is an input restriction due to the motor standard or the like. The present invention is applicable to such a motor. Furthermore, the life of the brush is long, the sliding noise can be reduced, it is economically beneficial, the brush can be shortened, and the motor can be reduced in size.

It is a perspective view which shows schematic structure of the motor using the brush which concerns on embodiment of this invention. It is a figure which shows the chemical structure of the water-soluble silicone oil which concerns on embodiment of this invention. It is a figure which shows the chemical structure of the fluorine-modified silicone oil which concerns on embodiment of this invention.

Explanation of symbols

1 Brush 2 Rotating body 3 Lead wire

Claims (7)

A carbon brush for an electric machine pressed against a conductive rotating body,
A material composed of aggregate and binder containing carbon as at least one component is a brush base material,
Water-soluble silicone oil is impregnated in the carbon brush for electric machine,
The carbon brush for an electric machine, wherein an impregnation amount of the water-soluble silicone oil is 0.2 to 10% by weight with respect to the brush base material. A carbon brush for an electric machine pressed against a conductive rotating body,
A material composed of aggregate and binder containing carbon as at least one component is a brush base material,
Fluorine-modified silicone oil is contained in the carbon brush for electric machine,
The carbon brush for an electric machine, wherein the content of the fluorine-modified silicone oil is 0.2 to 3% by weight with respect to the brush base material . The carbon brush for an electric machine according to claim 1 or 2,
A carbon brush for an electric machine comprising a metal compound . The carbon brush for an electric machine according to claim 3,
The carbon brush for an electric machine , wherein the content of the metal compound is 0.05 to 10% by weight with respect to the brush base material . A carbon brush for an electric machine according to any one of claims 1 to 4,
A carbon brush for an electric machine, wherein the binder is made of a synthetic resin . A carbon brush for an electric machine according to any one of claims 1 to 4,
A carbon brush for an electric machine, wherein the binder comprises a carbonized product of synthetic resin or a carbonized product of pitch . A carbon brush for an electric machine according to any one of claims 1 to 6,
A carbon for electric machines, characterized in that an electrically conductive metal film is formed on at least a part of the surface of the carbon brush excluding the surface of the carbon brush for electric machines that contacts the conductive rotating body. brush.

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