Airborne Wear Particles from Dry Clutches

Abstract

A significant part of non-exhaust particle emissions in cities comes from the wear of vehicle components. Several studies on airborne particles from the wear of disc brakes and tires have been completed. However, few publications can be found in the scientific literature regarding airborne emissions from dry clutches used in road vehicles. With this in mind, this preliminary study designs a clutch tribometer for the generation of airborne wear particles in a controlled environment. The number concentration and the size distribution of airborne wear particles generated from a typical dry clutch used in passenger cars are investigated. The tests are run at a constant rotational speed, and normal load. The results show that the particle number concentration from dry clutches exhibits a running-in period and a steady state, similar to the particle emissions from disc brake contact. A significant number of nanoparticles (aerodynamic diameter < 100 nm) are emitted from the dry clutch contact.