Patent ID: 7637240

Claim:
A balancer for an engine with a crankshaft, comprising: a rotatable drive balance shaft comprising a first balance weight and a first portion formed at a position offset from the first balance weight in an axial direction of the drive balance shaft, the drive balance shaft being adapted to be operatively connected with the crankshaft of the engine for rotation with the crankshaft; a drive gear fixedly disposed on the drive balance shaft; a rotatable driven balance shaft disposed parallel to the drive balance shaft, the driven balance shaft comprising a second balance weight and a second portion formed at a position offset from the second balance weight in an axial direction of the driven balance shaft, and a driven gear fixedly disposed on the driven balance shaft, the driven gear being meshed with the drive gear and transmitting a rotational force from the drive balance shaft to the driven balance shaft, wherein the second portion of the driven balance shaft is smaller in outer diameter than the first portion of the drive balance shaft.