When the brush runs on the collector ring, a uniform, moderate and stable oxide film will be formed on the contact surface, which is one of the main signs of the motor running well. The presence of this oxide film changes the contact characteristics of the brushes and the collector rings, reducing friction, reducing wear and extending service life. The oxide film is a composite film, and its composition is related to the type of brush and the material composition of the collector ring. The normal thickness of the oxide film is 8100m, usually 25m. Observation with an electron microscope shows that there are countless point contacts between the brush and the collector ring. Usually, the contact area is only a few thousandths of the total area of the brush.

The size of the contact area is determined by factors such as the motor speed, the hardness of the collector ring material, the machining accuracy, the yaw, the brush material and the pressure applied to the brush. Studies have shown that when the applied voltage is small, the oxide film is insulating. When the voltage rises to a certain value, the oxide film is destroyed. After breakdown, no matter how much the current increases, the contact voltage remains constant due to the increase in the conduction point and the enlargement of the conduction area. Scraper slip ring manufacturers produce a variety of electromechanical devices.

The slip ring structure is designed for a 20-year life, allowing for multiple maintenance procedures. It is recommended to use a carbon brush as the contact point. After maintenance, the bottom of the brush box and the collector ring surface should not exceed 3mm. If the gap is too large, sparks may be generated and the stability will be affected. machine. Using contact pins or brush bundles as contacts, spray EML conductive cleaner on the slip ring and brush pin or brush bundle surfaces to extend the life of the brush pins or brush bundles. The surface roughness of the new slip ring is 0.75~1.25m, and the brushes exceeding 0.75m will generate harmonic vibration and cause instantaneous disconnection, which is often misleading. Slip rings and carbon brushes below 1.25m wear relatively quickly. Roughness below 0.2 m should be avoided as much as possible.

Promoting the rapid formation of a conductive oxide film on the slip ring is the core of the slip ring manufacturer's manufacturing technology, and the machine can only be stabilized after the conductive oxide film is formed. The formation of the oxide film is completed at about 70 degrees. After the oxide film is formed, the temperature gradually drops to 40-50 degrees, forming a stable and good working environment.

After a good conductive oxide film is formed on the surface of the slip ring, the whole system has undergone a qualitative change, and the life of the slip ring and carbon brush has been increased by 10 times. A fatal phenomenon when the slip ring system is running is that the contact surface produces sparks, which is related to the pressure of the carbon brush, the material of the carbon brush, mechanical vibration, mechanical air gap, contact surface and other factors. carbon brush. You can check for arcing and many other phenomena in sequence. The pressure of the carbon brush is related to the pressure of the finger, the matching gap between the carbon brush and the brush box, and the oxidation and hardening of the brush wire, which must be solved by on-site analysis. The radial fit of the collector ring brush box is H7, the axial direction is H11, and the carbon brush is d11. This fit ensures a good fit gap after the system temperature rises.