Methodology to Optimize Radiator Fan Induced Steering Wheel Vibration of a Car

Electric radiator fan is a vital component within IC and EV passenger vehicle cooling system. However, due to its operation, it induces noise and in-cab vibration affecting human comfort level. This paper primarily focus on FMS (Fan Motor Shroud) assembly induced steering wheel vibrations in a vehicle under idle + AC ON condition. The entire NVH performance was cascaded from vehicle level to component level to evaluate for high steering wheel vibration and its transfer path analysis. Unit level vibrations study was also carried out using a rigid rig under controlled conditions. Based on FMS vibration analysis, it was observed that fan blade rotating imbalance leads the high vibrations within system. Thus, a balancing method with higher precision and accuracy was used to measure and balance the fan under all operating conditions. Sensitivity analysis had been carried out for fan imbalanced boundary conditions and operating speeds. FMS assembly standalone imbalanced value and steering wheel vibration objective data and subjectively co-relation was established with the help of universal testing buck. Based on this methodology, a robust radiator fan imbalance target was set which in turn induces acceptable steering wheel vibration and thus, eventually maintains brand image and customer comfort associated with a particular model.