斗提式散粮卸船机提升装置振动特性研究

Study on Vibration Characteristics of Lifting Device of Bucket Elevator Type Bulk Grain Ship Unloader

斗提式散粮卸船机是一种新型的散粮卸船机,提升装置由斗提机和螺旋喂料器组成。考虑到卸船用斗提机的悬臂工作状态,与传统斗提机的安装方式不同,同时会受风浪等因素的影响,针对提升装置的弯曲振动进行理论研究。计算得出提升段横截面对于形心轴的惯性矩和悬臂梁的等效弯曲刚度。建立提升装置竖直悬臂梁模型,利用微元法建立提升段弯曲振动的动力学方程,通过对端部质量块的力学分析,确定弯曲振动的边界条件,得出弯曲振动的频率方程。利用MATLAB求解频率方程,得出提升装置弯曲振动的前四阶固有频率。使用ANSYS对提升装置进行模态仿真,得到前四阶固有频率和振型。从理论结果和仿真结果的对比来看,前四阶频率的误差值都在5%以下,理论结果具有可靠性。研究为斗提式提升装置的固有频率计算提供了新的方法思路,研究结果为斗提式散粮卸船机的进一步研究提供依据。

The bucket-elevator type ship unloader is a new type of ship unloader for unloading bulk grain,of which the lifting device consists of a bucket and a screw feeder.Considering many situations,for instance,the working state of the bucket elevator used in the ship unloader is cantilever,and its installation method is different from the traditional one,and it would be affected by wind,waves and etc,the studies on the bending vibration of the 1ifting device are conducted.The material mechanics is used to calculate the moment of inertia of the cross section of the lifting section and the equivalent bending rigidity of the lifting section.Create the cantilever beam mode1 of the lifting device,then establish the dynamic equation of the bending vibration of the lifting section by differential element method.Through the mechanical analysis of the end mass,the boundary condition of the bending vibration is determined,and the frequency equation of the bending vibration is deduced.Using MATLAB to solve the frequency equation,the first four natural frequencies of the bending vibration of the 1ifting device are obtained.Using ANSYS,the moda1 simulation of the lifting device was performed to obtain the first four natural frequencies and formations.From the comparison between theoretical results and simulation results,the error values of the first four frequencies are below 5%,thus the theoretical results are reliable.The study provides a new method for calculating the natura1 frequency of the lifting device,besides,the research results provide a basis for further research on the bucket-elevator type bulk grain unloader.