Tree Balancing and internal combustion engine

The invention relates to a balancer shaft (10) adapted to be rotated by a crankshaft of an internal combustion engine. The balancer shaft (10) being equipped with bearings (12, 13, 14) to be rotatably mounted in a frame of the internal combustion engine and a cam (16) for interaction with a roll cam follower (18) for a fuel injection pump. The invention provides that said two bearings (12, 13, 14) are placed close to the two axial sides of the cam (16).