JPS60162439A - Small-sized motor - Google Patents

Abstract

PURPOSE:To prevent the surface of commutator segments from damaging by friction by mounting a member which impregnates secondary amine near a slide of the commutator on part such as a bracket 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 secondary amines having a -NH- bond. The atmosphere in a motor case made of a motor housing 13 and a bracket 12 becomes vapor atmosphere with the amine.

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, a video tape recorder, or the like.

Conventional Structures and Problems There are generally two types of brushes used in small motors.

One is to use elastic conductive materials such as copper, beryllium copper, copper-titanium alloys, phosphor bronze, and nickel silver thin sheets or wires, and noble metal alloys (such as aluminum).

This is a structure in which Pd, Pi, aluminum (1, Ctt, etc. and their alloys) are clad or joined to a part of a thin plate or wire by means such as spot welding, and the other is the thin plate or wire mentioned above. Sintered carbon brush (for example, C carbon, Muq carbon, Cu carbon, 5g CuC carbon and S
i Or MoS2 y Pb + carbon brushes containing epoxy resin, etc. as additives) are formed using conductive adhesive, spot welding, pressure bonding, etc., but in small motors with these brushes, When the commutator rotates, the commutator sliding part vibrates unnecessarily, which causes abnormal welding on the contact surface of the commutator sliding part to the commutator segment, and blackening (carbon and The problem is that foreign matter is often generated which promotes an abnormal phenomenon known as a mixture of sliding wear particles generated between the brush and the commutator segment.

In some brushes for small motors, a commutator sliding portion that slides on a commutator segment is molded integrally with a brush base that is supported by support means provided on, for example, the motor, the lid of the case, or the like. The state of 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 1-4 in a pressed state. This pressing force can be set to a required value by appropriately selecting the bending angle between the brush base 2 and the commutator sliding portion 3. Also, commutator
The segment 4 is fixed to the motor rotating shaft 6 via an insulating cylinder 6, 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 shortens the life of the brush, but also
If welding occurs at the position where it starts and leaves contact with each commutator segment 4 (section a in Figure 1), the surface of the commutator segment 4 will be rubbed and damaged due to the welding, and further damage will occur due to this abrasion. Cutting debris accumulates in the gap between the adjacent commutator segments 1-4, which causes the inconvenience of electrical conduction between the commutator segments, and the motor performance itself deteriorates. It had a lot of flaws. Incidentally, electric sparks are often generated at section a of the commutator sliding section.

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 occurrence of welding 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 suspended solids in the commutator sliding part 3 are noble metal alloy brushes or sintered carbon brushes as described above, and the suspended solids in the commutator segment 4 are AqCu, Ag.
ed, AgCuCd, Cu, Human U alloy, Ag
They are made of Pd alloy, AgCuTi alloy, etc., and when a noble metal alloy brush is used, since both are made of almost the same material, the sliding resistance is 1.0, and there is a disadvantage that scratches are likely to occur at the sliding interface. It's a great combination.

In addition, although the sliding resistance is lower when using a sintered carbon brush than when using a noble metal alloy brush, there is a risk of scratches, and the additives that make up the carbon brush are Impurities such as SiO2 are mixed in, which is an unfavorable combination that tends to cause scratches at the sliding interface, similar to noble metal alloy brushes.

The structure shown in Fig. 2a which does not have a means to suppress the electric sparks that cause these defects, that is, the one in which no vibration damping measures are taken for the commutator sliding part 3, is a commutator. The vibration of the sliding parts is large, and therefore welding easily occurs even when used at room temperature, making it difficult to obtain a product with a long life and excellent quality. Also, as shown in Fig. 2, a vibration-preventing rubber 7 attached to the commutator sliding part 3 with an adhesive 8 has good vibration absorption at room temperature.
It is possible to suppress the generation of sparks, but the upper temperature limit for use is 6.
When the temperature approaches 0℃, the viscosity of the adhesive decreases significantly, the adhesion of the anti-vibration rubber γ to the sliding parts decreases, the vibration absorption ability decreases, more sparks are generated, the life is shortened, and the quality deteriorates. It becomes unstable. Furthermore, as shown in FIG. 2C, the anti-vibration sheet 9 is attached to the commutator sliding part 3 with an adhesive 11 having adhesive 8 applied to both sides of the base 10, as shown in FIG. Compared to the above example, although the decrease in the viscosity of the adhesive at high temperatures is somewhat small, it is not sufficient to achieve long life and high quality at high temperatures.

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

Purpose of the Invention The present invention improves the sliding properties of the commutator sliding part and the commutator segment, prevents shortening of motor life due to scratch damage on the surface of the commutator segment, and improves the durability of equipment such as trenches and tape recorders. The present invention provides a high-performance small motor that can reduce wow and flutter when incorporated into a motor.

Structure of the Invention In order to achieve the above object, the present invention provides a brush base made of a thin plate or linear metal elastic body, and a commutator extending from the brush base or fixed to a part of the brush base. In a small motor equipped with a brush that has a sliding part, a member impregnated with a secondary amine, such as felt, is fixed or crimped with adhesive to a part of the mortar case, for example, near the commutator sliding part on the bracket. Install it by other means. This secondary amine does not have a benzene ring and has some linear carbon bonds, or
It has a side chain, and in its molecular structure, a singular mazoko has multiple −
It is a secondary amine with an NH-bond, and under 1 atm,
It is particularly effective to select a material with a boiling point of 250° C. from those with a boiling point around 100° C. depending on the usage situation. The structure is such that this secondary amine turns into vapor depending on the ambient temperature, and the inside of the motor case is under an atmosphere of secondary amine.

In order to simplify the configuration, a configuration may be used in which the secondary amine is directly applied to the brush or commutator sliding portion.

DESCRIPTION OF EMBODIMENTS FIGS. 3, 4 and 6 each show an embodiment of the present invention. Here, parts with the same names as those in FIG.
Felt impregnated with grade amine. Incidentally, the commutator sliding portion 3 is composed of a carbon brush.

In the embodiment of FIG. 3, the felt 14 is a bracket) 121
In the embodiment shown in FIG. 4, 7 malts and 14 portions are 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 addition, in FIG. 6, 15 is a rotor core attached to the motor rotating shaft 6;
6 is a winding wound around the rotor core 15, 17 is a permanent magnet fixed to the inner surface of the motor housing 13, and 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. part, and felt 1 is placed on the sliding part.
4 may be equipped.

In either case, the atmosphere inside the motor case including the motor housing 13 and the bracket 12 becomes a vapor atmosphere due to the secondary amine, and the atmospheric gas is intended to be adsorbed onto the surfaces of the brushes and commutator segments. However, the means to do so are not limited to this.

By the way, in the past literature and experiments, etc.

Data is being clarified by the state in which the moving part and commutator segment are likely to weld, or the state in which they are likely to cause sticking, abnormal wear, or poor continuity. Conditions where abnormalities are likely to occur are when the brush sliding part and the commutator segment are surrounded by a small area where they move, or when unsaturated cyclic hydrocarbons are present or adsorbed in the commutator segment itself. It is.

At this time, blackide (a mixture of carbon and sliding wear powder generated between the brush and the commutator segment)
Foreign matter that promotes abnormal sawing is generated.

This change occurs when the cyclic hydrocarbon is combusted by the arc between the sliding part and the commutator segment.
This is due to the fact that there is a large amount of carbon per unit, which burns without light, and -f's molecular structure, but because the bonding state of the produced carbon is dense, 4I! This is thought to be due to the formation of carbon from shellfish.

In addition, an atmosphere of hydrocarbons other than unsaturated cyclic hydrocarbons 4. It has been clarified that adsorption to the Shiki and Commutator segments results in soft carbon and does not lead to abnormal phenomena, although this is due to their 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 the commutator segment adsorbs about 1Q/lq of hydrocarbons, the abnormal phenomenon of the commutator segment will be alleviated and the life of the small motor will be extended (
However, this data is based on the case where there is no continuous replenishment of hydrocarbons).

The results were obtained (the results of the experiment are shown in FIG. 6).

Therefore, in the present invention, taking the above phenomenon into consideration, we have developed the
As shown in the embodiment shown in FIG. 6, a felt 14 impregnated with a secondary amine is placed inside the motor housing 13 and the bracket 12. These secondary amines are most different from unsaturated cyclic hydrocarbons in terms of their molecular structure, and therefore are the most distant from the formation of hard black compounds, which is one of the abnormal phenomena. It is also extremely soft, reducing the sliding resistance between the commutator sliding part and the commutator segment.

With the above configuration, an atmosphere suitable for the vapor pressure of secondary amines can be obtained in the motor case at high temperatures and low humidity where abnormal phenomena are likely to occur. Secondary amines that do not have a benzene ring, have linear carbon bonds, or have side chains strongly adsorb onto metal surfaces due to their polar force. This adsorption is due to the Van der Waals attraction, and compared to adsorbed organic gases, it is more strongly adsorbed and can be said to be in a stable adsorption state. By adsorption of this secondary amines, Pl.

Not only the commutator segments and brushes with strong catalytic action made of Au, Pd, A (J, etc.), but also C
It also adsorbs to the surface of the sintered carbon brush and other metal surfaces, preventing highly reactive gases (styrene monomer, toluene) from adhering to the surface.

This is because the adsorption force of the -NH- bond is stronger than, for example, van der Waals adsorption of styrene monomer or toluene. Furthermore, since it has an -NH- group in its molecular structure, it also has anti-rust properties that protect metals from corrosion. Therefore, metal parts can be stably protected for a long period of time.

Furthermore, for small motors whose normal operating environment ranges from -10'C to +80°C, substances with a boiling point of around 100°C at 1 atm, 250°C are particularly effective, and secondary amines Diptylamine...1
60"C, (boiling point under 1 atmosphere), etc.

The aforementioned secondary amines adsorb to the brush and commutator surfaces and form a monomolecular film, which greatly improves lubricity and significantly reduces wear on the contact parts (experimental results are shown in Section 6).
(shown in figure).

In addition, in FIG. 6, A and B indicate rectified waveforms in a styrene monomer atmosphere containing an unsaturated cyclic hydrocarbon;
is the clean waveform before the 60℃, 6%RH test, B is the 60”C
,, is the regular b1ε waveform after a 100 hour test at 5% RH. In addition, C and D show the confirmation results when approximately 10 μ9 of hydrocarbon (toluene) was adsorbed on the surface of the commutator segment, and C shows the rectified waveform before the 60°C and 6% RH test.
D is a rectified waveform after testing at 60° C. and 64RH for 300 hours. Further, K and F indicate the results of confirmation in an atmosphere of secondary amines according to the present invention, and E is 60°C.

Rectified waveform before 6%RH test, F is 60℃, 6chi RH1
This is the rectified waveform after 600 hours of testing.

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

■ Commutator segment for secondary amines.

By adhering to the brush surface, a lubricating effect is activated, which has the effect of preventing abnormal wear and scratch damage on the sliding parts.

■ Even if there is an organic gas with a benzene ring such as styrene monomer or toluene, it is protected by a film of secondary amines adsorbed on the brush and commutator segment surfaces.
The formation of black compounds is minimal, and poor contact between the brush and commutator segment can be completely prevented. In addition, since contact failure does not occur, the occurrence of chair noise is also reduced, and the speed of small motors that is caused by unstable contact is stabilized, resulting in the reduction of wow and flutter in equipment that uses small motors. It has the effect of reducing

■ As a result of grinding ■ and ■, the quality of small motors can be improved and the overall lifespan can be significantly extended.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventional example, FIGS. 2 a - c are diagrams each showing the configuration of a cobaltator sliding part of a conventional example, and FIGS. 3 and 4 are configuration diagrams of an embodiment of the present invention, respectively. , Figure 6a
, b are vertical and horizontal cross-sectional views of a small motor according to still another embodiment of the present invention, and FIGS. 6A and 6F are diagrams showing current waveforms of the conventional example and the non-fired motor. 3... Commutator sliding part, 4... Commutator segment, 12... Bracket, 13''゛°゛. N-Using, 14...2 Felt impregnated with grade amine. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure I Fourth mouth! (Figure 6 of α

Claims (1)

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