| 摘要 |
PURPOSE: To provide a crankshaft that has almost the highest torsional vibration with the minimum vibration amplitude and the minimum torsional stress by establishing the size of a crank arm supporting crank pin satisfied with the determined conditions. CONSTITUTION: A crankshaft 16 of 4 cylinder engine has respectively a pair of crank arms 31 to 38 and crank pins 25 to 28 in one body between a pair of journals 18 to 22 adjacent each other. In this invention, in order to minimize torsional vibration stress and flexure generated in the crankshaft 16 during engine operation, the sizes of each crank arms 31 to 38 are so selectively determined that they have the minimized mass and the most suitable stiffness for enduring the torsional vibration and other composite force generated in each crank arms 31 to 38. And as for the angle direction torsion, the stiffness of each crank arms 31 to 38 is increased or decreased in proportion to the distance from node of each crank arms 31 to 38. |
