CRANK SHAFT AND ENGINE WITH THE SAME

PROBLEM TO BE SOLVED: To provide a crank shaft capable of reducing the weight of a crank web more, securing the inertia mass of the crank web, and to provide an engine with the same. SOLUTION: A pair of crank weight parts 77 provided on a peripheral side of the crank web are separated from each other with a counter position T relative to a crank pin 34 between them, and a notch part 83 notching the peripheral shape of the crank web is provided on a peripheral side of a separated part between each crank weight part 77 of the crank web. In an engine 21 comprising the crank shaft 31, a cylinder axis C2 is offset relative to the crank axis C1, and the center of gravity position W of the whole of each of the crank weight parts 77 is offset toward a cylinder axis C2 side when a piston reaches the top dead center. COPYRIGHT: (C)2010,JPO&INPIT