Patent ID: 8640668

Claim:
A balancer device of an engine, comprising: an oil pump unit including a pump shaft driven by a rotation of the engine, a rotor driven by the pump shaft to increase a pressure of oil, and a pump housing storing the rotor therein; a balancer unit including an input gear, a pair of balancer shafts driven by the input gear, and a balancer housing storing the input gear and the balancer shafts therein; and a power transmission shaft rotationally coupled the pump shaft of the oil pump unit to the input gear of the balancer unit so as to transmit a drive force of the oil pump shaft to the input gear, wherein the pump housing of said oil pump unit and the balancer housing of said balancer unit are formed separately from each other, the pump housing has a journal hole at one end thereof which rotationally supports an end portion of the pump shaft via a bearing, the balancer housing has a journal hole at one end thereof which rotationally supports an end portion of the input gear via a bearing, said oil pump unit and said balancer unit are coupled to each other through a face contact such that an end face of said one end of the pump housing contacts an end face of said one end of the balancer housing and stored inside an oil pan of the engine, a cylindrical positioning member is inserted into the journal hole of the pump housing and the journal hole of the balancer housing for providing coaxial arrangement of the pump shaft and the input gear, and at least one of said one end of the pump housing and said one end of the balancer housing has at least one connection portion, the connection portion being configured to extend so as to connect a space inside said cylindrical positioning member inserted into the journal holes of the pump and balancer housings to an outside space of the balancer housing of the balancer unit.