| 摘要 |
PURPOSE:To miniaturize an engine by dividing a disk section formed in the radial direction from a fitting boss to a crank shaft into two, forming one of them on the outside in the axial direction and the other on the inside in the axial direction, and providing both static and dynamic unbalance on a flywheel. CONSTITUTION:A disk section 22 forming a flywheel 18 is constituted of two semicircular portions 22a and 22b along the diameter direction, the outside portion 22a has a uniform thickness, and the thickness of the inside portion 22b is increased toward the outer periphery. The flywheel 18 has dynamic and static unbalance. The position of the center of gravity and the mass are determined so that Ma X Ra X La = Mb X Rb X Lb, where Ma is the mass, Ra is the rotating radius of the center of gravity, La is the distance between the center of gravity and a crank pin 6 for the outside portion, and Mb, Rb, Lb are corresponding items for the inside portion. Only the inertial force generated by the flywheel 18 is applied to the crank pin 6, and the same balance as that provided with a counterweight on a crank web is obtained. |
