JPS60162440A - Small-sized motor - Google Patents

Abstract

PURPOSE:To prevent the surface of commutator segments from damaging by friction by mounting a member which impregnates alkylamide having -CONH- bond on part in a motor case. CONSTITUTION:A felt 14 is disposed near the side 3 of a commutator on a bracket 12. The felt 14 has a linear carbon bond or a side chain, and a sole or a plurality of alkylamide having a -CONH- bond. The atmosphere in a motor case made of a motor housing 13 and a bracket 12 becomes vapor atmosphere with the alkylamide.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a small motor used for driving a tape in, for example, a tape recorder or a video tape recorder.

Conventional Structures and Problems There are generally two types of brushes used in small motors. 1 is an elastic conductive material, such as copper or aluminum.
Noble metal alloys (e.g. Au,
This is a structure in which Pd, PC, Ag, Cu, etc. and alloys thereof) are clad or joined to a part of a thin plate material or wire rod by means such as spot welding, and the other is the thin plate material mentioned above, Alternatively, a sintered carbon brush (for example, C carbore, Ag carbon, Gu carboy, Agauc carbon, and Si
C, MO82, Pb.

Carbon brushes containing epoxy thread resin, etc. as additives) are formed using fully conductive adhesive, spot welding, or pressure metallization, but in small motors with these brushes, the commutator does not move when the commutator rotates. The sliding part vibrates unnecessarily, which can cause abnormal welding on the contact surface of the commutator sliding part to the commutator segment, and blackening (carbon and) due to spark generation. This is a problem because foreign matter, which is said to be a mixture of sliding wear particles generated between the commutator segments, which promotes abnormal phenomena, is often generated.

In some brushes for small motors, a commutator sliding portion that makes sliding contact with a commutator segment is molded integrally with a brush base that is supported by support means provided, for example, on the lid of a motor case. The contact between such a brush and a commutator segment is shown in FIG.

In FIG. 1, a bent commutator sliding portion 3 extends from a brush base 2 supported by a brush support means 1. This commutator sliding part 3 is connected to the brush base 2
It has elasticity due to being bent from above, and is in contact with the commutator segment 4 in a pressed state. This pressing force can be made into a safe case by appropriately selecting the bending angle between the brush base 2 and the commutator sliding portion t41X3. Furthermore, the commutator segment 4 is connected to the motor rotation shaft 6 via the insulating cylinder 6.
It is fixed to the rotor and rotates with the rotation of the motor.

Since the rotating commutator segment 4 and the commutator sliding part 3 are in sliding contact with each other, electrical sparks are likely to occur between them, and the generation of these electrical sparks can cause electrical noise and the commutator sliding part 3. Unfavorable conditions such as welding on the portion 3 will occur. The occurrence of this welding not only reduces the lifespan of the brush, but also
If welding occurs at the positions where it starts and leaves contact with each commutator segment 4 (section 4 in Figure 1), this welding will scrape and damage the surface of the commutator segments 4, and the The disadvantage is that cutting debris accumulates in the cap between adjacent commutator segments 4, which causes the inconvenience of electrical conduction between the commutator segments, resulting in a drop in motor performance itself. was there. Note that electric sparks often occur at the four parts of the commutator sliding part.

The biggest cause of this is the vibration of the brush. That is, electric sparks frequently occur due to the vibration of the brush, which promotes the generation of a molten layer and causes roughness of the sliding surface. As the roughness increases, the number of electric sparks increases, and eventually it becomes impossible to obtain the required characteristics of the motor, leading to the motor stopping.

Generally, the material of the commutator sliding part 3 is a noble metal alloy brush or a sintered carbon plan as mentioned above.
The material of the commutator segment 4 is MugGu,
Aged, AgCuCd, Cu, Au alloy.

Agpa alloy, AgCuTi alloy, etc., using negative metal alloy plan +111. In this case, since both are made of almost the same material, the sliding resistance is 19.
This is an unfavorable combination that tends to cause scratches at the sliding interface. Although the sliding resistance is smaller when using a sintered carbon plan compared to when using a negative metal alloy brush, there is a risk of scratches, and there is also a risk of scratches due to the Impurities such as 5i02 and the like are mixed in, creating an unfavorable combination in which abrasions are likely to occur at the sliding interface, similar to noble metal alloy brushes.

The structure shown in Figure 2(a) does not have a means to suppress the electrical sparks that cause these defects,
That is, if no vibration damping measures are taken for the commutator sliding part 3, the vibration of the commutator sliding part is large, and therefore welding easily occurs even when used at room temperature, resulting in a long life.
Good quality items are hard. Also, Figure 2(b)
The one shown in Figure 3, in which the anti-vibration rubber 7 is attached to the sliding part 3 of the commutator with the adhesive 8, has good vibration absorption at room temperature and can suppress the sound of sparks, but the upper limit temperature for use is 60°C. At temperatures close to It becomes unstable.

Furthermore, as shown in FIG. 2(C), a vibration prevention sheet 9 is attached to the commutator sliding part 3 with an adhesive 11 having a structure in which an adhesive 8 is applied to both sides of a base material 10. ,
Compared to the example shown in Fig. 2(b) above, the decrease in the viscosity of the adhesive at high temperatures is somewhat small, but it cannot be completely dissolved.
It is not possible to obtain long life and high quality at high temperatures.

In addition, the operating atmosphere temperature of this device is -10'C~''-
Many are used at 60°C.

Purpose of the Invention The present invention aims to improve the commutator sliding part and the sliding part of the commutator segment, prevent shortening of motor life due to scratch damage on the surface of the commutator segment, and improve equipment such as tape recorders, etc. The purpose of the present invention is to provide a high-performance small motor that can reduce wow and flutter when assembled into a motor.

Structure of the Invention In order to achieve the above-mentioned object, the present invention includes a plan base made of a thin or linear metal elastic body, and a plan base that is attached to the brush base or fixed to a part of the brush base. In a small motor equipped with a brush having a commutator sliding part, a member impregnated with alkylamide, such as felt, is glued to a part of the motor case, for example, near the commutator sliding part of the second bracket. Attach by fixing or crimping. This alkylamide does not have a benzene ring, has a linear carbon bond, or has a side chain, and has one or more single-layer 〇NH- bonds in its molecular structure, and is 1 atm. It is particularly effective to select a substance with a boiling point of 260°C from those with a boiling point near 100°C (=J) depending on the usage situation. is configured to be under an alkylamide atmosphere.In order to simplify the motor configuration, a configuration may be used in which the alkylamide is directly applied to the brush or commutator sliding portion.

DESCRIPTION OF EMBODIMENTS FIG. 3, FIG. 4, and FIG. 6 each show an embodiment of the present invention. Here, parts with the same names as those in FIG. 1 are given the same reference numerals; 13 is a motor housing; 13 is a motor housing; 14 is felt impregnated with alkylamide. Note that the commutator sliding rXli3i is composed of one carbon brush. In the embodiment shown in FIG. 3, the felt 14 is placed near the commutator sliding portion 3 on the bracket 12, and in the embodiment shown in FIG. 4, the felt 14 is mounted on the brush base 2.

Further, in the embodiment shown in FIG. 6, the motor housing 13 is equipped with a felt 14. In FIG. 6, 16 is a rotor core attached to the motor rotating shaft 6, 16 is a winding wound around the rotor core 16, and 17 is a permanent wire fixed to the inner surface of the motor housing 13. The magnet 18 is a bearing that supports the motor rotating shaft 6.

In each of these embodiments, the commutator sliding part 3 is fixed to the tip of the brush base 2, but as shown in FIG. It has a moving part, and felt 1 is placed on the sliding part.
4 may be equipped.

In either case, the atmosphere inside the motor case consisting of the motor housing 13° and the black hole 12 is
The purpose is to create a vapor atmosphere due to the alkylamide and adsorb the atmospheric gas to the surfaces of the brush and the commutator segment, but the method is not limited to this.

By the way, according to previous literature and implementations, it is easy to weld the commutator sliding part and the commutator segment.
Also, the conditions in which welding, abnormal wear, and poor conduction are likely to occur are being clarified. Abnormalities are likely to occur when unsaturated cyclic hydrocarbons exist or are adsorbed in the atmosphere of the sliding parts of the brush sliding part and the commutator segment, or in the commutator segment itself. . At this time, a foreign substance called blackide (a mixture of carbon and sliding abrasion powder generated between the brush and the commutator/seven segment) is generated which promotes abnormal phenomena.

This foreign material is caused by the fact that when unsaturated cyclic hydrocarbons are combusted by an arc between the sliding part and the commutator segment, the amount of carbon per unit volume is large, resulting in incomplete combustion;
This is due to the molecular structure of the shredded carbon, but it is thought that the bonding state of the formed carbon becomes dense, resulting in the formation of hard carbon.

In addition, the atmosphere of hydrocarbons other than unsaturated cyclic hydrocarbons -In!
It has been clarified that adsorption to air and commutator segments does not lead to abnormal phenomena because the carbon produced is soft, although this is due to its molecular structure. Based on these phenomena, we conducted long-term operation experiments using a commutator segment that adsorbed a small amount of hydrocarbons. In this experiment, ■ There is a high probability that abnormal wear will occur in the commutator segment under high temperature and low humidity.

■ If about 10 μg of hydrocarbons are adsorbed on the commutator segment, commutator segment 1. Abnormal phenomena of arc segments are alleviated and the life of small motors is extended.

(However, this data is based on the case where there is no continuous replenishment of hydrocarbons.) (The results of the experiment are shown in Fig. 6) Therefore, in the present invention, in consideration of the above phenomenon, Figs.
As shown in the practical row of FIG. 6, a felt 14 impregnated with an alkylamide is placed inside the motor housing 13 and the bracket 12.

These alkylamides are the most different from unsaturated cyclic hydrocarbons in terms of their molecular structure, and therefore are the ones that are the most distant from the formation of hard melanides, which is one of the abnormal phenomena.
Even if carbon is generated, it is extremely soft and reduces the sliding resistance between the commutator sliding part and the commutator segment.

In the configuration described above, an atmosphere suitable for the vapor pressure of the alkylamides can be obtained in the motor case at high temperatures and low humidity where abnormal phenomena are likely to occur.

Alkylamides that do not have a benzene ring, have a linear carbon bond, or have a side chain have \\single or multiple single layer 〇NH- bonds in their molecular structure, and -0ONH- bonds. strongly adsorbs to metal surfaces due to its polar force.

The adsorption by the -GONH- bond is more strongly adsorbed than the adsorbed organic gas due to the attraction of Funda Waals, and can be said to be a stable adsorption state.

By adsorption of this alkylamide, Pt, Mu, and Pd.

Not only the commutator segments and brushes made of 1 kg, etc., which have a strong catalytic effect, but also those made of CU,
It also adsorbs to the surface of the cut sintered carbon brush and other metal surfaces, preventing highly reactive gases (styrene monomer, toluene, etc.) from adhering to the surface.

This is because the adsorption force of the -〇〇NH- bond is stronger than, for example, van der Waals adsorption of styrene monomer or toluene. Also available are brushes, commutators,
Even when combustion occurs in the arc between segments, alkylamides have oxygen in their molecular structure, so there is little generation of tar due to incomplete combustion, and there is no formation of black particles that can cause poor contact. It is very small, burns well, and does not cause contact failure.

Moreover, for small motors whose normal operating environment range is -10°C to +60°C, the boiling point at 1 atmosphere is 100°C.
From nearby substances, those at 250°C are particularly effective,
The types of alkylamides are n-ethyl acetamide...205°C (boiling point under 1 atmosphere).

The above-mentioned alkylamides are adsorbed onto the surfaces of the brush and commutator to form a monomolecular film, so the lubricity is greatly improved and the wear of the contact parts is significantly reduced. (The results of the experiment are shown in Figure 6.) In Figure 6, K),
(B) shows the rectified waveform in a styrene monomer atmosphere containing an unsaturated cyclic hydrocarbon, and (A) shows the rectified waveform at 60°C1s%R.
) 1 Rectified waveform before test, (B) is 60°C 1s%RH
This is the rectified waveform after a 100 hour test. Also, (C1, (
D) shows the confirmation results when approximately 10g of hydrocarbon (toluene) was adsorbed on the surface of the commutator segment.
(C> is the rectified waveform before the 60°C 1s%RH test, (D
) is the rectified waveform after a 300-hour test at 60°C and 1s%RH. Furthermore, (El, (F) shows the confirmation results in an alkylamide atmosphere according to the present invention, and α) is 6
Rectified waveform before 0°C1s%RH test, a) is 60°C
This is a rectified waveform after a 1s%RH 1500 hour test.

Effects of the Invention As is clear from the above description, the present invention provides the following effects.

■ By adsorbing alkylamides to the surfaces of commutators, components, and plans, a lubricating effect is activated and has the effect of preventing abnormal wear and abrasion damage on sliding parts.

■ Even if there is organic residue such as styrene monomer yatoluene, which has a benzene ring, it is protected by a film of alkylamides adsorbed on the brush and commutator segment surfaces. Poor contact between segments can be prevented. In addition, since there is no contact failure, the generation of electrical noise is reduced, and the speed of small motors due to unstable contact is stabilized, resulting in a reduction in wow and fracturing in equipment where small motors are used. There is an effect that can be obtained.

(2) As a result of the above ■ and ■, the quality of small motors has improved 1
~, the lifespan can be significantly extended.

[Brief explanation of drawings]

, @ Figure 1 is a diagram of the configuration of conventional shiori, and Figure 2 ta) to (C) are Sowa. Figure 3 shows the configuration of a conventional commutator sliding part, respectively.
4 and 4 are block diagrams of embodiments of the present invention, respectively.
Figures (a) and (b) are a vertical cross-sectional view and a cross-sectional view of a small motor according to still another embodiment of the present invention, and Figure 6 (A)
-(F) are diagrams showing rectified waveforms of the conventional example and the present invention. , 3... Commutator sliding part, 4...
Commutator segment, 12...bracket, 13...housing, 14...alkylamide fully impregnated felt. Name of agent: Patent attorney Toshio Nakao (1 person)
j Figure 3 Figure 5 Figure 6 OV□ θy□□

Claims (1)

[Claims] A small motor has a brush mechanism and a commutator, and has a structure in which the brush and the commutator slide in contact with each other.The motor case has a linear carbon bond or a side chain, and its molecular structure has a A small motor provided with an atmosphere of alkylamides having one or more -C0NH- bonds.