Estimation Of Gearbox Vibration And Noise Based On FE Preprocessor Gear Meshing Force Algorithm

Gear transmission is the key equipment of the ship’s power system.Due to the transmission of power through the gear’s alternate meshing,meshing vibration will inevitably occur,which is one of the main factors affecting the vibration and noise of the ship during sailing.However,due to the large power,large size,complicated structure,and long development cycle of marine gear transmissions,once vibration and noise problems occur after completion of manufacturing,they are often difficult to deal with due to technical and schedule factors.Therefore,for marine gear transmissions,it is particularly important to estimate vibration and noise in synchronization with the design.The most important thing to estimate the vibration and noise of a gearbox is to calculate the gear meshing excitation force.At present,the commonly used calculation methods are difficult to balance efficiency and accuracy,and there is still a certain gap with the actual needs of the project.In recent years,the FE Preprocessor method for calculating the meshing force has developed rapidly and can take into account both efficiency and accuracy.This paper explores the application of this method to the calculation of the meshing force of the gearbox,and then analyzes the vibration and noise of the gearbox.The slice method is compared,and the feasibility of the vibration and noise estimation of the gearbox is explored with experimental verification.The main contents are as follows:(1)The FE Preprocessor method is used to solve the dynamic meshing excitation of helical gears and compared with the commonly used slice method.The calculation results of the two methods are similar,but the FE Preprocessor method can better reflect the effect of load changes.(2)We will create a finite element model for vibration and noise calculations,analyze natural frequencies and modal shapes,conduct modal tests on the test gearbox,and modify the finite element model based on the modal correlation theory.The MAC(Modal Assurance Criterion)value of the line has been increased from less than 0.6 to over 0.8 after correction,laying a foundation for the calculation of vibration response and noise estimation.(3)The meshing excitations calculated by the FE Preprocessor method and the slice method are applied to the finite element model,and the response of the box is calculated by the modal superposition method.The radiated noise of the box is calculated by the ATV(Acoustic Transfer Vector)method.Comparing the calculation results of the two methods,it can be seen that the noise calculated by the FE Preprocessor method is slightly higher than the slice method,and the deviation of the calculation results of the two methods increases after increasing the load.(4)Finally,we carry out a gearbox operation test to test the vibration acceleration and air noise of the gearbox,compare the test data with the vibration and noise results estimated by the two methods,and obtain that the estimated results of the FE Preprocessor method are closer to the test data.The deviations between the vibration prediction results and test results of the FE Preprocessor method under low load conditions are 3.3% and 3.7% smaller than those of the slice method,and the deviations of the FE Preprocessor method are 5.2% and 6.0% smaller than those of the slice method under high load conditions.The comparison results of noise estimates are similar in conclusion.The preliminary results show that the FE Preprocessor method can reduce the calculation deviation and improve the calculation accuracy,and the calculation accuracy is more obvious when the load is large,which has certain engineering application value.