Balancer device for internal combustion engine

Abstract

There is provided a balancer device for an internal combustion engine that suppresses lubricating oil from failing onto a reduction gear and a pump drive gear provided to drive and rotate an oil pump and thereby suppresses an increase in resistance against rotation between the reduction gear and the pump drive gear. The balancer device for the internal combustion engine includes a lower side housing on which a balancer drive gear, a first balancer shaft including a first balance weight, a first gear, a second gear, a second balancer shaft including a second balance weight, and the reduction gear are mounted. The balancer device also includes an upper side housing formed in such a shape that covers the balancer drive gear, the first balancer shaft including the first balance weight, the first gear, the second gear, the second balancer shaft including the second balance weight, the reduction gear, and the pump drive gear from above in the state that the oil pump is assembled with the upper side housing such that the pump drive gear is meshed with the reduction gear. The upper side housing is assembled with the lower side housing. The balancer device further includes an exposure opening formed in the upper side housing such that only the balancer drive gear is exposed from the upper side housing to be meshed with an engine-side gear.