Experimental Study of Drive Rattle Noise Reduction in Passenger Car by Transmission Case Modification 2019-01-1561

Low noise and vibration is one of the prime requirements of passenger car. Passenger car is having various noises inside passenger cabin due to various moving parts. Gear rattle noise is a very common problem of transmission. Gear rattle is generated because of impact of free gears .Impact of gear is caused by torsional vibration of engine transferred through clutch. When gear tooth impact then sound wave is generated and it is transmitted through Transmission case. Because of tooth impact, vibrations are generated and these vibrations are transferred to shaft, bearings and transmission case. Because of vibration of transmission case, noise is generated.The sound absorption and structural vibration of transmission case can be changed by changing the geometrical features of transmission case. Transmission case thickness is one of the important parameter that affects both radiation noise and structural noise.This paper describes the study of reduction of drive rattle in passenger car by transmission case modification through NVH test and experimental modal analysis of transmission case.