抄録
This paper describes the reduction of the vibration and noise of engine gear units for automobile. The vibration and noise of the engine balancer were examined. The running tests of the engine balancer were carried out using the power-absorbing-type engine balancer testing machine. In the engine balancer, two types of gears were used, that is, S45C gears and hybrid structure gears of which teeth and rim part were made of S45C and gear body was made of FC250. The effects of rotational speed, applied torque, backlash and gear structure on the vibration and noise of the engine balancer were determined.