Vibracoustic, a global automotive noise, vibration, and harshness (NVH) expert, developed decoupling solutions for auxiliary components in electric vehicles (EVs). Automotive manufacturers are facing a range of new NVH challenges as auxiliary systems such as coolers, pumps, and compressors are not belt-driven in e-mobility applications.
EVs don’t use internal combustion engines but they still require auxiliary systems like cooling for batteries, motors, and the cabin or to support the braking system. Decoupling of the systems became an important focus for vehicle manufacturers, as the noise and vibration they generate is no longer masked by the internal combustion engine. The auxiliary systems aren't positionally constrained by the location of the engine, meaning they could be packaged differently within the chassis, leading to a host of new NVH issues. With their ‘holistic system’ approach to vehicle NVH, Vibracoustic’s engineers are developing mounting solutions to safely decouple auxiliary components from coolers and pumps to compressors to increase durability as well as the overall driving comfort.
The decoupling solutions consider wider vehicle NVH considerations and include the option for single or double isolation layers. A double isolated bracket was used for a vacuum pump for the braking system of a standard C-segment vehicle to eliminate unwanted noises of the braking system. While these NVH issues had no impact on the performance of the vehicle’s braking system, many customers would perceive this as a safety-critical issue or attribute it to poor build quality.
Vibracoustic engineers developed decoupling solutions for eCompressors, electronically powered compressors used in EVs for air conditioning and battery cooling. By analyzing the excitations, the engineers developed a specifically tuned mounting concept, which, in combination with optimized brackets, is combined into a mounting assembly and produced with cost efficiency in mind. This eliminates the vibrations and noise generated inside the compressor and thus minimizes the vibration level for particularly sensitive conditions, such as during high-voltage fast charging. The engineering team achieved these objectives through exhaustive simulation and testing, determining the optimum component geometry and ideal rubber compound for maximum effectiveness and service life.