| 摘要 |
PURPOSE:To effectively reduce the bending vibration in an actual-use revolution region by installing a counter weight corresponding to a crank pin set at the position closest to a flywheel, onto a crank wave on the opposite side to the flywheel, keeping a crank pin interposed in the axial direction. CONSTITUTION:The first counterweight 4A' installed onto the first crank wave 13A is installed onto the second crank wave 13B, and the fourth counterweight 14D' installed onto the eighth crank wave 13H is installed onto the seventh crank wave 13C. Therefore, the weight position of a whole rotary body 9 shifts close to the center in the axial direction in comparison with the prior art, and the characteristic frequency of the rotary body 9 is increased, and also the resonance frequency is varied in the direction departing from the ordinary revolution region of an engine towards a high revolution side. Therefore, the bending vibration of a crankshaft 10 in the ordinary revolution region is reduced in comparison with the prior art, and strength can be improved, and noise can be reduced. |
