Some Regularities of Friction and Wear in Current-Loaded Sliding Contact, Copper - Electric Brush.

The effect of the speed of sliding, pressure, current density, air temperature and the extent of sparking on the friction and wear parameters of an electric sliding contact formed by high-grade copper and an electrographite brush is investigated. These factors have a substantial effect on wear. Moreover, with an increase of current density, the wear of copper decreases but the wear of electric brushes increases. Normal (oxidation) wear occurs at the optimum speed of V equals 30 m/s. At different temperatures abrasive wear takes place. At 40 degree C copper wear is minimal. These data can be useful for the design of dc machines.