Noise, Vibration and Harshness problems in rotors and drums show up in different forms in automotive brakes. The NVH problems may reside either in foundation brakes, apply systems, anti-lock systems or having nothing to do with brake systems but are related to other automotive components such as suspensions, wheel bearings, tire and wheel, drive axle or body structure. The NVH issue is a major warranty cost issue that the car manufacturers and suppliers have to face.
Hayes Lemmerz has patented a new rotor design where lowering noise and vibration were the main design criteria. We have used a design concept unique to the brake industry but commonly used to dampen noise. The rotor introduces a sound deadening layer under the brake cheeks. The brake cheeks are attached to brake ribs or fins by a safe and reliable joining method, with the noise damping layer molded on the rear of brake cheeks. We have achieved noise reduction of 50% compared to current production design rotors. More work is being done to analytically understand the NVH problem and testing the HAYES QUIET ROTOR DESIGN on instrumented vehicle tests like DST (Detroit Suburban Traffic) and LACT (Los Angeles City Traffic).