JPH0250180B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to improvements in a brush sliding contact material (hereinafter referred to as "sliding contact material") for making a brush plate material for a brush contact that slides on the outer periphery of a commutator of a small motor. Traditionally, phosphor bronze (P0.01-0.5%, Sn 7.0-9.0%, remainder Cu) has been mainly used to make the brush plate material of the brush contact that slides on the outer periphery of the commutator of small motors. However, since oxides are generated due to mechanical and electrical corrosion during sliding, the wear resistance is poor, and the wear powder is likely to be generated, and when the wear powder is generated, noise is generated. The present invention has been made in order to eliminate such drawbacks, and aims to provide a phosphor bronze-based sliding contact material that has excellent wear resistance. The sliding contact material of the present invention has P0.01 to 0.50% by weight,
Sn6.3 to 9.0% by weight, at least one of Sb, Mo, Pb and Zn in total 0.5 to 10% by weight and the balance Cu
It is made of alloy. In such a sliding contact material of the present invention, P0.01~
The Cu alloy is made of 0.50% by weight of Sn, 6.3 to 9.0% by weight of Sn, 0.5 to 10% by weight of at least one of Sb, Mo, Pb and Zn in total, and the balance Cu, because of the Sb generated during sliding of the brush contact. This is because at least one oxide of Mo, Pb, and Zn acts as a lubricant and improves wear resistance, and since these oxides are soft, they are easily removed by sliding action, resulting in high contact resistance. This is because it does not become unstable; if it is less than 0.5% by weight, it will not be effective as a lubricant, and if it exceeds 10% by weight, more oxides will be generated, resulting in high contact resistance and instability. be. Furthermore, by setting the contents of P, Sn, and Cu within a range that does not change the composition ratio of the conventional alloy material, the characteristics of the conventional alloy material can be exhibited without being impaired. be. Next, brush plate materials for brush contacts made from the sliding contact material for brushes according to the present invention and the conventional sliding contact materials for brushes will be explained. A conventional alloy material is used as a base material, and Sb is added to it to make a sliding contact material with the composition shown in Example 1 in the table below, and in the same manner, a book with the composition shown in the left column of the table below is made. Widths made from the sliding contact material for brushes which is an embodiment of the invention and the conventional sliding contact material for brushes
A brush plate material of 0.5 mm and a thickness of 0.15 mm is cut into a length of 10 mm. As shown in the above figure, the brush plate material 2 of the brush contact 3 is made by holding one brush plate material 2 and has a thickness of 0.2 mm on the outer periphery.
A commutator 1 for a small motor with a diameter of 10 mm and a length of 6 mm, which has three contact pieces 1a made of 10% by weight of Ag-Cu.
A rotation test was conducted on the commutator under the test conditions described below by sliding the commutator in sliding contact with the outer periphery of the brush so that they were vertically facing each other, and the wear amount and contact resistance of the brush plate material 2 of the brush contact 3 were measured. The results shown in the column were obtained. Test conditions Voltage: 24V Current: DC 250mA Commutator rotation speed: 2000 rotations/min Commutator rotation time: 300 hours Brush contact force: 10g

[Table] As is clear from the above table, the amount of wear of the brush plate material of the conventional brush contact was 60 to 80 μm,
The amount of wear of the brush plate material of the brush contact in the example is 20 to 30μ
It can be seen that the wear resistance decreases significantly in m, indicating that the wear resistance is excellent. Further, it can be seen that while the contact resistance of the conventional brush plate material was 1 to 7 Ω, the contact resistance of the brush plate material of the example was 0.6 to 0.8 Ω, which was extremely low and stable. This is because the wear resistance of the brush plate material of the example is improved by the oxide lubricants of Sb, Mo, Pb, and Zn generated during sliding, and the soft oxides are easily removed by the sliding action. This is because the contact resistance of the brush plate material is low and stable. As detailed above, in the sliding contact material of the present invention, the oxides of Sb, Mo, Pb, and Zn generated during sliding act as lubricants, and these oxides are easily removed by the sliding action. The brush plate material of the brush contact made by this method has significantly improved wear resistance, the generation of wasted powder has been greatly reduced, and the generation of noise has been drastically reduced.
Also, the contact resistance is low and stable. Therefore, there are excellent effects such as less variation in the rotational speed of the commutator of the other small motor.

[Brief explanation of the drawing]

The figure is a perspective view showing the state of contact between the commutator and brush contacts of a small motor. 1...Commutator, 1a...Contact piece, 2...Brush plate material, 3...Brush contact.

Claims (1)

[Claims] 1 P0.01-0.50% by weight, Sn6.3-9.0% by weight, Sb,
At least one of Mo, Pb and Zn in total of 0.5~
A sliding contact material for a brush, characterized in that it is made of a Cu alloy of 10% by weight and the balance being Cu.