船舶轴系横向振动的模拟实验与分析

在船舶轴系试验台上对两种轴系布置方案进行了轴系横向振动实验.自由振动的实验与分析表明尾轴填料函有一定支撑作用,对轴系的横向振动有影响.受迫振动的实验指出:除“螺旋浆叶频”外还有另外的共振转速.对轴心轨迹的研究表明:由于轴承的支撑刚度是各向异性的,存在多个一阶共振转速.由功率谱阵图可获得轴系的“基频”等有用信息.

The Simulation Experiments and Analysis for Lateral Vibrations of Ship's Propulsion Systems

This paper presents the lateral vibration experiment of two shaft system plants on a shafting test bed.The lateral vibrations of propeller shaft systems are measured and analyzed by means of various methods and the same results are obtained.The experiments of free vibrations indicate that The stuffing box has the function of supporting and restraining the shaft.The critical whirling speeds of shafting are affected by the stuffing box.However, for certain shaftings, the computed critical whirling speed of shafting by prevailing method is not accurate since no provision is made for the effects of stuffing box.In addition, only the "blade frequency of the propeller" is considered as the critical whirling speed in the vibration analysis of ship's shafting, but the forced vibration tests show that there are other critical whirling speeds in the usable rotating speed range besides "blade frequency of the propeller".The investigation of axial centre locus show that there is a band of critical whirling speeds owing to anisotropy of bearing rigidity.In addition, the authors point out that the fundamental frequency of shafting may be obtained by power spectrum array.