JPS60162445A - Small-sized motor - Google Patents

Abstract

PURPOSE:To prevent the surface of commutator segments from damaging by friction by mounting a member which impregnates ketones having -CO- polarity group 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 ketones having a -CO- polarity group. The atmosphere in a motor case made of a motor housing 13 and a bracket 12 becomes vapor atmosphere with the ketones.

Description

DETAILED DESCRIPTION OF THE INVENTION The industrial field of application T3A relates to small motors used for driving tapes, for example in tape recorders, video recorders, etc.

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

One is a conductive material with elasticity, such as copper, beryllium copper, copper-titanium alloy, phosphor bronze, nickel silver thin sheet material, or wire material, and noble metal alloy (such as Au.

Pd, Pt, Ag, C! There is a structure in which a part of the thin plate material or wire rod is joined by means such as spot welding, and the other is a structure in which a part of the thin plate material or wire rod mentioned above is joined by cladding or spot welding. Knotted carbon brush (
For example, C carbon, A9 carbon, Cu carbon,
AgCu carbon and those materials Sz Cp M
o S 21 P b + Carbon brushes containing epoxy resin etc. as additives) are formed using conductive adhesive, spot welding, Yes, - means crimping method, etc., but small size brushes with these brushes are used. to the motor
When the commutator rotates, the commutator sliding part vibrates unnecessarily, which causes abnormal welding on the contact surface of the commutator sliding part with the commutator segment, and blackening due to spark generation. (A mixture of carbon and sliding abrasion particles generated between the brush and the commutator segment) often occurs, causing problems such as the formation of foreign particles that promote abnormal phenomena. 6. For small motor brushes, Some commutator sliding parts that come into sliding contact with the commutator segments are integrally molded with a brush base that is supported by support means provided, for example, on the lid of the 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 plan base 2
It has elasticity due to being bent from above, and is in contact with the commie data segment 4 in a pressed state. This pressing force can be achieved by appropriately selecting the bending angle between the brush base 2 and the commutator sliding part 3.
It can be any value you want. Further, the commie data segment 4 is fixed to the motor rotating shaft 6 via an insulating cylinder 5, 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. Inconvenient conditions such as welding on the portion 3 will occur. And, the occurrence of welding with the brush not only shortens the life of the brush, but also
If welding occurs at the position where each commutator segment 4 starts to come into contact with the commutator segment 4 and at the position where it leaves the commutator segment 4 (section a in Figure 1), the surface of the commutator segment 4 will be scratched and damaged by the welding, and furthermore, this abrasion will cause damage to the surface of the commutator segment 4. The generated cutting debris accumulates in the mesh between the adjacent commutator segments 4, which causes the inconvenience that the commutator segments are electrically connected to each other, and the performance of the motor itself deteriorates. there were. 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 N welding and causes roughness of the sliding surface. As the roughness increases, the generation of electric sparks further increases, and eventually it becomes impossible to obtain the required characteristics of the motor, leading to the motor starting and stopping.

Generally, the material of the commutator sliding part 3 is a noble metal alloy brush or a sintered carbon brush as described above.
The material of the commutator segment 4 is AgCu,
AgCd, AgCuCd, Cu, Au alloy, AqPd alloy, AgCuTi alloy, etc., and when noble metal alloy Plano is used, both of them are
Since they are made of similar materials, the sliding resistance is as high as 1.0, which is an unfavorable combination that tends to cause scratches at the sliding interface.

Furthermore, 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 compounded materials that make up the carbon brush contain SiO2. This is an unfavorable combination, as impurities such as these are mixed in, and scratches are likely to occur at the sliding interface in the same way as precious 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 structure in which no vibration damping measures are taken for the commutator sliding part 3, The commutator's sliding parts vibrate greatly, 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. The anti-vibration rubber 7 is still attached to the commutator sliding part 3 with an adhesive 8 as shown in Figure 2.
The adhesive pasted has good vibration absorption at room temperature and can suppress the generation of sparks, but the viscosity of the adhesive decreases significantly when the temperature reaches the upper limit of 60°C, causing damage to the sliding parts of the anti-vibration rubber 7. The adhesion force to the product decreases, the vibration absorption ability decreases, the generation of sparks increases, the product life becomes short, and the quality becomes unstable. Furthermore, as shown in FIG. 2C, the anti-vibration sheet 9 is attached to the commutator sliding part 3 and the adhesive 11 is applied to both sides of the base material 10 with the adhesive B applied. Compared to the example shown in Figure 2, the decrease in the viscosity of the adhesive at high temperatures is somewhat small, but it is not sufficient, and it is not possible to obtain long life and high quality at high temperatures.

Kotobuki, the operating atmosphere temperature of this device is -10'C~+s
Many are used at 0°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 sliding performance of the commutator segment. The purpose of the present invention is to provide 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 includes a plan base made of a thin plate or linear metal elastic body, and a plan base extending from 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 ketone, such as felt, is fixed with adhesive or attached to a part of the motor case, for example, near the commutator sliding part on the bracket. Install by crimp method or other means. This ketone is a ketone that does not have a benzene ring, has a linear carbon bond, or has a side chain, and has one or more -C〇- polar groups in its molecular structure, and is under 1 atm. , its boiling point is 1
It is particularly effective to use materials with a temperature of around 00°C to 250°C depending on the usage situation. The structure is such that this ketone turns into p-vapor depending on the ambient temperature, and the inside of the motor case is in a ketone atmosphere. Note that in order to simplify the motor configuration, a configuration may be used in which the ketone 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, and 12 is a bracket for holding a brush etc., 13 is a motor housing, and 14 is felt impregnated with ketone. Note that the commutator sliding portion 13 is made of a 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.

In the embodiment shown in FIG. 6, the mortar housing 13 is equipped with a felt 14. In addition, in FIG. 6, 16 is a rotor core attached to the motor rotating shaft 6;
16 is a winding wound around the rotor core 11, 17 is a permanent magnet fixed to the inner surface of the motor housing 13, and 518 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 any of the embodiments, the atmosphere inside the motor case such as the motor housing 13° bracket 12 is a vapor atmosphere due to ketones, and the atmosphere gas is intended to be adsorbed onto the surfaces of the brushes and commutator segments. Well, this is not the only way to do it.

By the way, in literature and experiments at this size, it has been found that the commutator sliding part and the commutator segment are easily welded.
In addition, the conditions in which welding, abnormal wear, and poor conduction are more likely to occur are being clarified. Abnormality is likely to occur: The condition is when unsaturated cyclic hydrocarbons are present or adsorbed in the atmosphere of the sliding part of the fringe and the commutator segment, or in the commutator segment itself. .

At this time, blackide (carbon and brush and commutator)
A foreign substance is generated that promotes an abnormal phenomenon called ``sliding wear powder generated between segments (mixed with each other)''.

This foreign material is caused by incomplete combustion due to the large amount of carbon per unit volume when the unsaturated cyclic hydrocarbon is burned by the arc between the sliding part and the commutator/segment, and also by its molecular structure. However, this is thought to be because the bonding state of the produced carbon becomes dense, resulting in hard carbon.

In addition, in the atmosphere of unsaturated cyclic hydrocarbons and adsorption to the commutator segment, the carbon produced is soft, due to its molecular structure.
It has been clarified that this does not lead to abnormal phenomena. 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 commie data segment under high temperature and low humidity.

■ If about 10 μq of hydrocarbons are adsorbed in the commutator segment, 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. ) results were obtained. (The results of the experiment are shown in FIG. 6) Therefore, in the present invention, in consideration of the above phenomenon, FIG.

As shown in the embodiments of FIGS. 4 and 6, a felt 14 impregnated with ketones is placed inside the motor housing 13 and the bracket 12. These ketones differ most 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 black compounds, which is one of the abnormal phenomena, and even if carbon formation occurs, it is extremely It is soft and reduces the sliding resistance between the commutator sliding part and the commutator segment.

In the above configuration, at high temperatures and low humidity where abnormal phenomena are likely to occur, an atmosphere similar to the vapor pressure of ketones is obtained within the motor case. Ketones that do not have a benzene ring and have a linear carbon bond or a side chain are
It has one or more monolayer 0- polar groups in its molecular structure, and the -CO- group strongly adsorbs to the metal surface due to its polar force.

Adsorption by -CO- groups is more strongly adsorbed than organic gases to be adsorbed due to van der Waals attraction.
This can be said to be a stable adsorption state. By adsorption of this ketone, Pt
Of course, the commutator segments and brushes made of materials such as Au, Pd, and Ag, which have strong catalytic effects, are
It is still adsorbed to the surface of the sintered carbon brush and other metal surfaces, and highly reactive gases (styrene monomer) to the surface.

Prevent the adhesion of toluene, etc.

This is because the adsorption power of the -〇〇- group is stronger than the van der Waals adsorption of, for example, styrene monomer or toluene. In addition, even if combustion occurs due to the arc between the brushes and commutator segments, ketones have oxygen in their molecular structure, so there is almost no tar generation due to incomplete combustion, resulting in poor contact. The formation of melanized substances is subtle, and it burns well and does not cause contact failure.

Moreover, the boiling point of a small motor whose normal operating environment range is -10℃~@10℃(゛) is 100℃(゛) at 1 atmosphere.
Among substances near τ1, those at 260'C are particularly effective, and listed by type of ketone: ■ 2 octanone -174°C (boiling point at 1 atm)
■ 2nonanone ・195℃ (boiling point under 1 atmosphere)
■ Co-phosphoric acid dienal 218'C (boiling point under 1 atmosphere) ■ 2-undecanone 229°C (boiling point under 1 atmosphere), etc.

The above-mentioned ketones adsorb to the surfaces of the plan and commutator and form a monomolecular film, so lubricity is greatly improved and wear of the contact parts is significantly reduced.

(The results of the experiment are shown in Figure 6.) In Figure 6, A and B indicate rectified waveforms in a styrene monomer atmosphere containing unsaturated cyclic hydrocarbons, and A
is the rectified waveform before the 60°C, 6%RH test, B is the 60'C
, 5. This is the rectified waveform after a 100-hour RH test. or,
C and D show the confirmation results when hydrocarbon (toluene) was adsorbed on the surface of the Comy Data Segment at a concentration of approximately 10/7 (J), and C is 60"C.

Rectified waveform before 6%RH test, D is 60”C, 5%RH
This is the rectified waveform after a 30o hour test. Furthermore, E, F
shows the confirmation results in a ketone atmosphere according to the present invention,
E￥'i 60°C, 5%RH Rectified waveform before test, F is 60°C, 5%RH1500 test (i(D@(At waveform).

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

■ By adhering to the surface of commutator segments and planes, a lubricating effect is exerted, which has the effect of preventing abnormal wear and abrasion damage on sliding parts.

■ Even if there is an organic gas with a benzene ring such as styrene monomer or toluene, it will be protected by a film of ketones adsorbed on the brush and commutator segment surfaces, and the formation of blackened substances will be subtle, and the Poor contact can be prevented. In addition, since contact failure does not occur, the generation of electrical noise is reduced, and the speed of small motors that is caused by unstable contact is stabilized, resulting in less wow and flutter in equipment that uses small motors. This has the effect of reducing

■ As a result of the above ■ and ■, the quality of small motors has improved,
Can significantly extend lifespan0

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a conventional example, FIG. 2 a % C is a diagram showing the configuration of a commutator sliding part of a conventional example, and FIGS. 3 and 4 are configuration diagrams of an embodiment of the present invention, respectively. FIGS. 6a and 6b are longitudinal and cross-sectional views of a small motor according to still another embodiment of the present invention, and FIGS. 6A to 6F 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-...-Felt impregnated with ketones. Name of agent: Patent attorney Toshio Nakao 3rd person
m Fig. 4 Fig. 5 Fig. 6 oV-1111-----
−−−−−−−−−−−−OV□

Claims (1)

[Claims] A small motor that has a brush mechanism and a commutator, and has a structure in which the brush and commutator slide in contact with each other, has a linear carbon bond in the motor case, or has a side chain, and has one or more carbon bonds in its molecular structure. A small motor with an atmosphere of ketones having 〇- polar groups.