Research On Technology Of Depressing Vibration And Noise Based On Thrust Unit Used In Gearbox

With the increasing application of high-power marine reducer, technology of shockabsorbing and noise reduction on reducer gets more attention from the field of Marineengineering. In addition to optimization of the related structural parameters ofcomponents, it has become a key technology in the design process of marine reducer tosolve the problems from vibration and noise utilizing extra mechanical structure.Because of the requirement of transfer more load, it is of great significance and veryurgent to develop new device and its systematic design theory.Based on the two different running states from the reducer with thrust units or not,thesis analysed the rationality and excellent performance of installing thrust units andestablished a systematic method used to design thrust units combined with currenttechnical theory of depressing vibration and noise. The combined effect of installingthrust units on gear drive is confirmed by the static and dynamic analysis andrelevant trials according to forming hydrodynamic lubrication between thrust unit andmain gear and yielded a good result of depressing vibration and noise. The physical andmathematical model ascertained is the foundation of analysis and research according tothe interaction between thrust unit and gear.For above-mentioned gear driving model, the binding effect on main gear installedthrust units is confirmed and theoretical relation between natural frequencies and thebinding effect of gear wheel vibration is derivated. CAE of natural frequencies andmodals of main gear is conducted under ABAQUS simulation on the basis of differentrunning states and gained different running effects. Based on simulation results, thesisanalysed and deduced the influence rules of different designed sizes of thrust unitsused。Besides that, research work established the mathematical theory models ofhydrodynamic lubrication between main gear and thrust unit, infered the influence ruleon lubrication after installing under MATLAB based on large amounts of data.Combined with the rules obtained, mechanical vibration and various constraints,thesis refined further the design process and optimum design model of thrust unit.Efficacy coefficient method is adopted to get the optimal solution of thrust unit designunder current usage requirements. The contrast between simulation results andexperimental data under ABAQUS and MATLAB confirmed correctness and effectiveness of design process and mathematical model of thrust unit.