Dual mass flywheel (DMF) is an excellent solution to improve the noise, vibration, and harshness (NVH) characteristic of any vehicle by isolating the driveline from the engine torsional vibrations. For the same reason, DMF’s are widely used in high power-density diesel and gasoline engines. However, the real-world usage conditions pose a lot of challenges to the robustness of the DMF. In the present work, by capturing the Real-World Usage Profile (RWUP) conditions, a new methodology is developed to evaluate the robustness of a DMF fitted in a Sports utility vehicle (SUV).
Ventilation holes are provided on clutch housing to improve convective heat transfer. Improvement in convective heat transfer will increase the life and will reduce clutch burning concerns. Cities like Mumbai, Chennai, Bangalore, roads will have clogged waters during rainy season. When the vehicle was driven in such roads, water enters inside the clutch housing through ventilation holes. Prolonged usage of vehicle in this condition results in water entering inside the DMF. DMF has grease over the springs to reduce friction. Water entering inside the DMF will reduce the viscosity of grease and subsequently leads to erosion of grease from DMF. This will result in metallic noise concern in Engine ON condition.
In the present work, author presents test methodology that shall be used to reproduce the metallic noise concern during development phase. The methodology is the combination of water wading test carried out at 500 mm of water level and subsequently subjecting the vehicle to city drive and high drive profile test of 1000 km. The co-relation was also established with real world failures. Authors also propose design alternatives that shall address metallic noise concern due to water entry. Based on the results of this proposed methodology, the robustness of the DMF could be improved. The paper explains the typical robustness measures needed inside the DMF to avoid real-world NVH failures and the test methodology to evaluate the same.