Experimental Analysis of Balance-Induced Vibrations in Vehicle Shafts

Extensive research has been conducted in recent years to mitigate damages caused by undesired vibrations in motor vehicles used for transportation. Vibrations occurring in highly active moving components of vehicles not only lead to discomfort in driving comfort but also reduce the material’s service life, causing fatigue and structural damage. Rotating elements in vehicles, such as the shaft (cardan shaft), crankshaft, and gears, can be sources of problems. In this study, vibrations resulting from an imbalance problem in the vehicle shaft were experimentally investigated, and the effects of balancing on the vehicle shaft were evaluated. For this purpose, vibration data were measured at three different points on a vehicle. Vibrations generated by the shaft under different road conditions and vehicle speeds were recorded and compared before and after balancing. The results of the study demonstrated a one-third reduction in vibration amplitude at the point beneath the driver's seat, which is directly associated with the comfort of both driver and passengers. Specifically, under the most demanding conditions (80 km·h⁻¹ speed and an uneven road surface), the vibration amplitude induced by the unbalanced driveshaft reached a high value of 2198 µm; after balancing, a reduction of approximately 65–70% in this amplitude was achieved at the measurement point under the driver's seat. In contrast, no significant difference was observed in the vibrations measured at the engine block and the luggage compartment. The findings indicate that vibrations originating from the vehicle driveshaft can be substantially mitigated through proper balancing.