Analysis And Experimental Verification Of Herringbone Gear Vibration Characteristics For Variable Operating Condition

Herringbone gears have high load-bearing capacity and can eliminate the axial force generated by helical gears.This is widely used in heavy machinery transmission industry such as aviation engine,vehicle engineering and ship propulsion.The continuous development of modern industrial system makes people put forward higher requirements for mechanical transmission system,and herringbone gear transmission system is one of them.In order to better meet the requirements of modern industrial production,it needs to break through in many aspects such as transmission smoothness and noise suppression.The construction of a scientific vibration model of herringbone gear transmission system can predict its dynamic performance at the design stage and effectively reduce its transmission noise,which is of great significance to the design of herringbone gear transmission system.In this paper,the dynamics simulation and vibration response analysis of herringbone gear transmission system and herringbone gearbox are carried out by applying finite element analysis method,and the axial vibration characteristics of herringbone gear transmission system are thoroughly studied by measuring and verifying with a test bench.Firstly,based on the basic theory of kinematics and gear meshing,it provides a fundamental concept about the gear meshing stiffness and a method to solve the gear tooth meshing stiffness.A pair of herringbone gears is modeled and the meshing stiffness of a pair of herringbone gears in operation is simulated by the finite element method.The mesh stiffness variation law of herringbone gear system with unbalance loading is studied,and the variation characteristics of the mesh stiffness affected by tooth profile modification are also analyzed.Secondly,as the theoretical basis of gear system dynamics,its general solution procedure is given.On this basis,a herringbone gear train bending-torsion-shaft twelve-degree-of-freedom dynamics analysis model is established under the action of multi-physical quantities by using the centralized parameter method and ignoring the specific connection between shaft and gear hub.The vibration rules of the herringbone gear transmission system in different directions under the influence of meshing stiffness,meshing shock,load torque and input speed are analyzed.Then,a three-dimensional model of the gearbox body is established,and its constrained mode is analyzed after finite element meshing.The reaction force at the drive and driven wheel bearings is obtained by solving the established dynamics model,and the reaction force is applied at the reference point of the bearing block of the gearbox,which is used as the excitation force.The modal superposition method is used to solve for the vibration response of the entire gearbox,so as to obtain the vibration rules at each reference point of the gearbox.Finally,to evaluate the proposed theoretical model,a practical axial vibration test is conducted using a herringbone gear transmission system with unbalance loading.The torque measurement instrument is adopted to collect various input and output signals of the gearbox in real time to complete the gear transmission efficiency analysis and various performance tests.The axial vibration characteristics of herringbone gear transmission under different operating conditions are analyzed,and the measured data are compared with the theoretical data to verify the feasibility and rationality of the theory in this paper.