A kind of preparation method of tungsten disulfide composite material for carbon brush

Abstract

The invention provides a method for preparing a tungsten disulfide composite material for a carbon brush. The raw material components of the composite materials, namely tungsten trioxide, sulphur, silicon carbide and a catalyst, are in a mass percentage ratio of 1:(0.28-0.8): (0.006-0.38):(0.0005-0.005). The method comprises the following steps: firstly, respectively preparing suspensions from carbon carbide and tungsten trioxide, adding a dispersing agent, controlling the pH value, adding a rare-earth catalyst and sulfur into a precursor solution prepared from urea and absolute ethanol, mixing, aging and baking to obtain mixed powder; and loading the mixed powder into a boat, introducing hydrogen under protection of trace argon in the furnace to perform high-temperature sintering, and finally preparing tungsten disulfide composite materials in different size fractions by means of grinding and vibrating screen classification. According to the method, the lubricating performance of tungsten disulfide and hard grinding performance of silicon carbide are organically combined, when the carbon dioxide works on the surface of a commutator, the tungsten disulfide which is attached to the surface of the silicon carbide and infiltrated inside the silicon carbide play a role in lubricating, so that scratch and damage to the surface of the commutator can be reduced.

Description

technical field [0001] The invention relates to a preparation method of a tungsten disulfide composite material, in particular to a preparation method of a tungsten disulfide composite material for carbon brushes. Background technique [0002] As a new technology, composite materials have the characteristics of improving product performance, reducing production costs, improving work efficiency, and improving product quality. Tungsten disulfide is a new type of fine tungsten product and an important friction material. One of its important uses is as a lubricant. Its physical and chemical properties are very excellent, and it is known as the new "king of lubrication". Its friction coefficient is only 0.03, and its dry friction performance is better than other materials. It can be used not only under normal lubrication conditions, but also for certain lubrication conditions. In harsh working environments such as high temperature, low temperature, high load, high vacuum, radiat...

AI Technical Summary

Problems solved by technology

During the long-term sliding process of the carbon brush with the rotor, a thick protective film will be formed on the surface of the commutator. If the film is partially detached and other local defects occur over time, current concentration will occur in the detached part, resulting in deterioration of the rectification characteristics, or even The surface of the carbon brush is uneven, and if the current is too large, it will also cause damage to the surface of the commutator

In order to solve this problem, an abrasive such as silicon carbide is usually added to the carbon brush, so that the film formed on the surface of the commutator when the carbon brush is working can be removed by silicon carbide. However, due to the extremely high hardness of silicon carbide , often due to the uneven dispersion caused by some large particles or flocculation, the surface of the commutator will be scratched as the carbon brush slides for a long time, resulting in a decrease in the working efficiency of the carbon brush, which in turn reduces the working efficiency of the motor, and also generates noise

In the production process of carbon brushes, the current practice is to directly mix tungsten disulfide as a lubricant and silicon carbide as a grinding agent with other carbon brush raw materials. The lubricant tungsten disulfide and silicon carbide as a grinding agent are often mixed Uneven, after the carbon brush is made, the film formed by the lubricant on the surface of the commutator cannot be eliminated evenly and stably by the grinding agent, making the surface of the commutator uneven or damaged, and the local current on the surface is too large, which affects the carbon brush and commutator. life of the commutator, resulting in reduced motor efficiency and instability