Patent 7350498 was granted and assigned to Kawasaki on April, 2008 by the United States Patent and Trademark Office.
A crankshaft equipped in an engine, including an oil passage through which oil is drawn from a crank journal to a crank pin. The oil passage has an inlet formed at a peripheral region of the crank journal. When a plane including a center axis of the crank journal and a center axis of the crank pin crosses a peripheral surface of the crank journal at two cross portions, the inlet is located to be spaced apart in an opposite direction to a rotational direction of the crank journal from a journal side cross portion located on an opposite side of the crank pin with respect to the center axis of the crank journal. The oil passage is configured to extend to be spaced apart from the center axis of the crank journal as seen from a direction of the center axis of the crankshaft.