| 摘要 |
PROBLEM TO BE SOLVED: To provide an internal-combustion engine crankshaft that enables reduction in the vibrations that occur in the crankshaft and the frictional resistance and wear between a con rod and a crank pin. SOLUTION: An internal-combustion engine crankshaft 2 comprises first and second crank-webs 23 and 24 that have different forms located between a pair of the main bearings 17 and 18, and a crank pin 25 on which a con rod 12 is axially supported. When the balancing weight of a first counter weight 23a is made to be W1, the balancing weight of a second counter weight 24a, W2, and the distances between G1-G2 and P, being the first and second distance of center of gravity, are made to be L1 and L2 respectively, wherein P is an imaginary plane including the center shaft line C2 of a cylinder 4 intersecting the line of axis of rotation C1 of the crankshaft 2, and G1 and G2 are the center of gravity of the first and the second counterweights 23a and 24a respectively, an equation is given as follows: W1+W2=W Wherein, W constitutes a balance weight to be set in order to reduce the inertial force of the reciprocating parts such as a piston 11 and the con rod 12, etc. Further, the balancing weight of the first and the second counter weight 23a and 24a, and the first and the second distance of center of gravity are so set that the products of W1×L1 and of W2×L2 will become equal or approximately equal. |
