Static And Dynamic Characteristics Analysis Of Dual-Rotor System Of Spiral Bevel Gear Grinding Machine

Spiral bevel gears are widely used in important fields such as automobiles,aviation,navigation,and construction machinery due to their advantages of high coincidence,strong bearing capacity,and low transmission noise.For heavy-duty transmission gears,high flank accuracy is required to r educe flank wear.Gear grinding is an important process to ensure the accuracy of the tooth surface.The static and dynamic performance of the grinding wheel spindle of the gear grinding machine will directly determine the processing accuracy and processin g efficiency of the gear grinding machine.Therefore,this paper takes a domestic CNC spiral bevel gear grinding machine grinding wheel box as the research object,establishes the static and dynamic model of the spindle-eccentric shaft dual-rotor system,and analyzes the static and dynamic characteristics of the dual-rotor system.Static test experiments and modal test experiments are used to measure the static stiffness and natural frequency of the dual rotor system.The main research work of this paper is as follows:(1)Considering the effect of gyro moment and centrifugal force,the pseudo-static model and stiffness analytical model of multi-row combined angular contact ball bearing are established.The Newton-Raphson iterative algorithm is used to solve the problem cyclically,and the solution algorithm is optimized to solve the problems that the initial value of the model is difficult to select and iterative convergence is difficult.And based on the bearing model,the influence factors of the four sets of bearings in the grinding wheel box are analyzed.(2)The static model of the dual-rotor system is established,and the influence of bearing preload and axial load on the static stiffness of the system is analyzed.At the same time,several sets of bearing-rotor system statics experiments with different combinations and static stiffness measurement experiments under different bearing preloads are designed to obtain the static characteristics of the dual-rotor system and verify the theoretical model results.(3)Based on the global transfer matrix method,the dynamic model of the main shaft-eccentric shaft dual rotor system is established.The first two critical speeds and mode shapes of the main shaft and the eccentric shaft are calculated,and the effect s of the preload,axial load and speed ratio of the four sets of bearings on the critical speed of the system are analyzed.According to the design specification of rotor unbalance,assuming the rotor unbalance and its position,the unbalance response of t he main shafteccentric shaft double rotor system is analyzed,and the unbalance response amplitude and dynamic stiffness of the main shaft front end are obtained.(4)The experimental modal tests of three structural forms are designed.The natural frequency and mode shape of the system are obtained by hammering method.The finite element model of the main shaft-eccentric shaft double rotor system is established by ANSYS,and the modal analysis of the system is carried out.The natural frequency and mode shape of the system are compared from the transfer matrix method,the finite element method and the modal test,and the validity of the model is verified.