Ⅴ型多缸柴油机曲轴动平衡当量环质量计算及分析

Equivalent Ring Mass Calculation and Analysis for Crankshaft Dynamic Balance of Ⅴ-Type Multi-Cylinder Diesel Engine

柴油机的动平衡性能对其振动有显著的影响,曲轴设计平衡重以消除或者部分消除惯性力和力矩.对曲轴进行动平衡试验时,为了模拟活塞连杆组产生的惯性力和力矩,需要对曲轴加装当量环.采用图解法,分析了Ⅴ型多缸柴油机的惯性力和力矩的平衡性,以及曲轴的内平衡,设计了平衡重;计算了活塞及连杆组的力和力矩不平衡量,将其当量到曲柄销处以计算当量环质量;建立了带平衡块和当量环的有限元模型,施加角速度载荷,校核其平衡性.结果表明:曲轴平衡性良好,质心处于曲轴轴线上,当量环准确地模拟了活塞连杆组的惯性作用.

The dynamic balance performance of the diesel engine has a significant impact on its vibration.The balance weight of the crankshaft is designed to eliminate or partially eliminate inertial forces and moments.In the dynamic balance test of the crankshaft,it is necessary to install equivalent rings to the crankshaft in order to simulate the inertial force and moment generated by the piston and connecting rod set.By applying the graphic method,the balance of inertial force and moment of the V-type multi-cylinder diesel engine and the internal balance of the crankshaft are analyzed,and the balance weight is designed.The force and moment unbalance of the piston and the connecting rod set are calculated,and it is equivalent to the crank pin to calculate the mass of equivalent ring.A finite element model of the crankshaft with counterbalances and equivalent rings is established,and the angular velocity load is applied to check its balance.The result shows that the crankshaft has good balance,and its centroid is on the crankshaft axis.The deformation is basically zero during operation.The equivalent ring simulates accurately the inertial effect of the piston and the connecting rod set.