| 摘要 |
PURPOSE:To reduce vibration by providing a heavier weight at the reciprocating part of an engine and setting the inertia efficiency of a flywheel high. CONSTITUTION:A flywheel F is disposed at the end part of an engine, the first, the second and the third cylinder K1, K2 and K3 are arranged in order after the flywheel, and a propeller P is disposed at the side opposite to the flywheel, forming a vibration mode curve M which passes through them. A greater ratio of amplitudes of (d) at the end of the engine and at the end of the propeller (e) may provide a smaller amplitude which is produced at the end of the engine. The torsional amplitude of (d) is in proportion to approximately a square of (d)/ (e). Under the condition of the same total vibromotive force, a greater difference between a total inertia efficiency at the engine side and that at the propeller side lower than it may provide smaller torsion amplitude. In two-cycle three- cylinder engine, its inertia efficiency may be increased by increasing the weight of the cylinder part, however, the three-cylinder engin has an extremely short full length. In the engine, even if having a minimal inertia efficiency, an amplitude ratio of (d)/(e) may be greater than 1 by mounting a flywheel which has an inertia efficiency over that of one piston part of the engine. |
