New Developments of an On-Vehicle Brake Pad Waste Collection System

The design of a braking system involves a delicate balance between the friction pair, the disc and pad, where the pad is a complex blend of constituents to provide predictable characteristics, typically, a known and consistent friction level. In its base form the brake has to absorb the vehicle kinetic energy by converting it into heat. This heat absorption by the friction pair can result in chemical and physical interactions with the release of debris about which we know little. Other than environmental concerns, brake dust causes unnecessary problems with wear, thermal gradients (hot banding) and NVH. This paper is concerned with the removal and collection of brake debris from the friction interface - the debris being regarded as solids and airborne particles, the latter less than 10 mu m in size. The test procedure consisted of a Burnish program followed by 8 different drive cycles. The overall effects of debris removal is then reported for each test. It will be shown that, by careful design of air circulation within a collection system, over 92% of dust generated may be removed and collected. It will also be shown that debris collection results in reduced rotor and pad wear and that the brake temperatures during the braking event are not significantly affected. The impact on brake cooling and brake operating temperatures during a customer usage-based braking schedule are under study. The implementation of providing a solution "at source" may provide the automotive industry with a system to meet current U.S. legislative requirements. It will also help to satisfy future costly global legislation. In addition the module will serve as a "real life" mobile laboratory where the OEMs may gather data from the filters to gain a greater understanding of the characteristics of the debris generated during braking - saving time and money on research. This is the first paper in a series which introduces the benefits of using the on-vehicle CBPModular brake wear debris collection system.