Research And Analysis On Vibration Reduction Of Integrated Diesel Generator Set For Vehicle Precision Equipment

Due to its strong maneuverability,high working efficiency and powerful functions,the integrated vehicle for precision equipment equipped with diesel generator set is widely used in military special operations and emergency rescue.However,with the high degree of integration of special vehicles,the vibration and noise of the diesel generator sets equipped with it have seriously affected the working accuracy of vehicle-mounted precision equipment.In order to reduce the vibration impact caused by the unit,according to the unit vibration theory and engineering practice,through the combination of test and finite element analysis,the unit is optimized for the situation where the vibration amount of the important part of the unit is large,and the optimized the vibration performance of the unit is analyzed.The specific research contents are as follows:(1)Based on the vibration damping theory and finite element analysis method,the dynamic model of the unit double-layer vibration damping system is proposed,and the equivalent stiffness and damping of each layer of the double-layer vibration damping system is obtained by fitting the damper stiffness and damping.To pave the way for subsequent dynamics analysis and vibration analysis.(2)Taking a 75k W power car of a certain model as the research object,the vibration test is carried out.By testing the vibration amount(amplitude,speed and acceleration)in the x,y,and z directions of thirteen important measuring points of the diesel generator set,the vibration amount in all directions and the vibration level difference of the shock absorber part of the units are obtained under the different operating conditions.Through the analysis of the test data,the results show that the vibration amount of the diesel engine,generator and cooling water tank is large,and the maximum vibration level drop of the shock absorber is 12.3411d B,which is greater than 10d B.It can be seen that the use of the shock absorber has a good effect on the transmission of the unit vibration weakening effect.(3)The three-dimensional model of the unit is established by using three-dimensional design software.Then the dynamic analysis is performed by finite element software.And the basic frequency of the unit is solved using the analysis method of the natural frequency and modal vector of the multi-degree-of-freedom system to obtain the first 15 modal frequencies and vibration type cloud diagram of the unit.Then the dynamic analysis results are compared with the data obtained from the test.The results show that the frequency curve of the periodic driving force is a single peak shape.When the frequency is higher or lower than 25 Hz,the forced vibration of the unit is relatively small.(4)The unit is optimized by changing the damper damping,increasing the number of shock absorbers,and improving the overall assembly plan and base structure of the unit,and perform vibration analysis on the actual vibration conditions of the unit.By comparing the vibration performance of the unit before and after optimization,it is concluded that the method of optimizing the base structure achieves the best vibration reduction effect,and the maximum stress value of the vibration reduction equipment can be reduced from 0.83MPa to 0.63MPa before optimization.The acceleration is controlled below 150deg/sec~2,and the peak value of the three-dimensional vibration curve of the base is reduced by an order of magnitude compared with that before optimization.The above research on the vibration performance of diesel generator sets meets the requirements of engineering applications and has high practical application value.