Title :
Electrically and frictionally derived mound temperatures in carbon graphite brushes
Author :
Bryant, Michael David ; Yune, Young Gill
Author_Institution :
Dept. of Mech. Eng., Texas Univ., Austin, TX, USA
fDate :
6/1/1989 12:00:00 AM
Abstract :
Thermal mounding in brushes can cause concentrations of electrical and mechanical loading. Joule heating due to current constriction and plastic work dissipation associated with sliding friction give rise to very intense subsurface heat sources local to the thermal mound. Coupled with the nonlinear material thermal properties of brush grade carbon graphites, temperatures of thousands of degrees Celsius can result. Numerical and analytical simulations of mound temperatures are presented as the mound evolves from cold to hot. The temperature field about a thermal mound in an electrical brush is estimated using a heat conduction equation with frictional and electrical internal heat sources. Properties vary realistically with temperature, and variations due to changes in current, sliding speed, and other factors are also presented
Keywords :
brushes; digital simulation; graphite; C brushes; Joule heating; analytical simulations; current; current constriction; electric load concentration; electrical brush; electrical internal heat sources; friction heating; graphite brushes; heat conduction equation; intense subsurface heat sources; mechanical load concentration; mound temperatures; nonlinear material thermal properties; numerical simulation; plastic work dissipation; sliding friction; sliding speed; temperature field; temperatures; thermal mound; Analytical models; Brushes; Conducting materials; Couplings; Friction; Organic materials; Plastics; Resistance heating; Temperature; Thermal loading;
Journal_Title :
Components, Hybrids, and Manufacturing Technology, IEEE Transactions on