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Success of the vehicle in the market depends on comfort provided while usage, which also includes noise, vibration and harshness (NVH). In order to achieve comfort level, the NVH levels have to be as low as possible. Powertrain is the main source of NVH, in which internal combustion engine consists of crank shaft and balancer shaft. Crank shaft gear is connected and driven by crank shaft and balanced by integral eccentric mass coupled with gear. Balancer shaft is used for additional balancing of rotating masses. Pair of crank shaft and balancer shaft gears generates noise and vibration when unbalance in the system and backlash in the gears increase while usage. The practice of interposing a vibration isolator on the surface of gear has been so far resorted for preventing transmission of vibration, therefore reduction in noise. In the work presented, balancer gear was made with sandwich design to reduce noise. Sandwich design comprises of Inner hub and outer ring with lug projections.

Comfort is a key factor in the automobile industry. Vehicles are designed to provide optimum comfort levels to passengers and drivers. The agricultural industry is a vital sector and requires long hours of operation for which comfort levels are a priority. To achieve these comfort levels Noise, Vibration, and Harshness (NVH) engineering is done, which includes computer-aided and prototype testing to troubleshoot problems and provide necessary solutions. This research work is based on the final stage of tractor development, during which an abnormal rattle noise was observed. This paper presents the airborne and structure-borne NVH study on a tractor by measuring sound pressure and vibration levels at vehicle and engine levels. A preliminary inspection of the tractor indicated the presence of abnormal noise during operation. For a detailed study, the engine was removed from the vehicle and mounted on a testbench to conduct a series of tests.