JPH0260742B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to improvements in sliding contact materials for brushes. Conventionally, various materials have been used as sliding contact materials, and in particular, as sliding contact materials for brushes, materials with excellent hardness, corrosion resistance, spring properties, etc., such as Pd 30 to 50% by weight, Ag 20 to 40% by weight, Cu20 Alloy materials consisting of ~40% by weight were widely used. However, brush contacts made of this alloy material soften and adhere when sliding with the commutator, which tends to generate abrasion particles, resulting in unstable contact resistance and noise generation. The present invention has been made to eliminate such drawbacks, and provides a brush that uses the above-mentioned alloy material as a base material and slightly adds a specific material to the brush to prevent softening and improve adhesion resistance. The present invention aims to provide a sliding contact material for use in the present invention. The sliding contact material for brushes of the present invention has a composition ratio of
Pd-Ag-Cu is 93-99.5% by weight and the balance is 30-50% by weight of Pd, 20-40% by weight of Ag, 20-40% by weight of Cu.
At least one of Cr, Mg and Zr in total of 0.5 to 7
% by weight. In the sliding contact material for brushes of the present invention, the composition ratio is 30 to 50% by weight of Pd, 20 to 40% by weight of Ag, and 20 to 40% by weight of Cu.
Pd-Ag-Cu in weight% is 93 to 99.5% by weight and the balance is at least one of Cr, Mg and Zr in total of 0.5 to 99.5% by weight
The reason why it is set at 7% by weight is to prevent softening during sliding due to precipitates in order to improve the adhesion resistance of the conventional alloy material. If it is less than 0.5% by weight, the effect cannot be exhibited, and if the total content of at least one of Cr, Mg and Zr exceeds 7% by weight, the amount of oxides generated increases, contact resistance becomes high, and it becomes unstable. It is what it is. Furthermore, by setting the contents of Pd, Ag, 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. . Next, a conventional alloy material is used as a base material, and Cr is added thereto to obtain a brush sliding contact material having the composition shown in Example 1 in the table. Brush wires with a wire diameter of 0.7 mm were made using the sliding contact material and the conventional sliding contact material for brushes, each was cut to a length of 8 mm, and two wires were placed in parallel with one end having a width of 10 mm and a length of 13 mm. A brush contact was made by welding to a 0.2 mm thick base material and bending a 2R arc-shaped contact part at the other end. Then, each brush contact was brought into contact with a disk-shaped commutator, and the commutator was rotated in forward and reverse directions to perform a sliding test under the following test conditions, and the wear amount and contact resistance were measured. The results shown in the column were obtained. Test conditions Current: DC 0.6A Voltage: 12V Load: Resistance load Rotation speed: 1000 rotations/divided speed: 130-120m/min Contact force: 100g Test time: 7 hours

[Table] As is clear from the above table, it can be seen that the brush contacts of Examples 1 to 15 had significantly less wear than the conventional brush contacts, and the contact resistance was low and stable.
This is because the sliding contact material for brushes of the present invention, which constitutes the brush wire of the brush contacts of Examples 1 to 15, is prevented from softening during sliding by at least one of Cr, Mg, and Zr, and is resistant to freezing. This is because it improves adhesion. As detailed above, the sliding contact material for brushes according to the present invention has significantly superior wear resistance compared to conventional sliding contact materials for brushes, generates extremely little wear powder, and generates almost no noise. This has the advantage that it is possible to obtain a brush contact having a lower and more stable contact resistance than when using conventional brush contact materials.

Claims (1)

[Claims] 1 Pd-Ag-Cu with a composition ratio of 30-50% by weight, 20-40% by weight, and 20-40% by weight of Pd-Ag-Cu, with the balance being at least one of Cr, Mg, and Zr, totaling 0.5-7%. % by weight of a sliding contact material for a brush.