Modeling And Transmission Accuracy Analysis Of Fixed-axis Cylindrical Gear Drive System With Elasticity And Errors

Gear drive,as the most widely-used core assembly unit in machinery industrial equipment,tends to the developing direction of higher precision and better performance.And transmission accuracy of the system is a significant index for its performance.In gear drive system,transmission precision and tooth surface contact performance are influenced by the machining errors,assembly errors and elastic deformations of the components.It is significant to quantificationally analyze the influence of various geometrical errors and stiffness factors on gearing performances for the analysis and design of precise gear drive system.This paper proposes accurate and quick simulation models and performance analysis methods of gear drive system with errors and elasticity.Concrete research contents are as follows:Firstly,based on the generating theory of involute and gearing conjugation principle,precise rigid geometry model of involute gears are established.According to the definitions and distribution rules of gear machining errors,gear models with machining errors are established.Based on SDT theory and coordinates transformation theory of positions and postures of rigid bodies,error transfer models of shafting components are established,by which assembly errors of relative positions and posture of gear sets are obtained.Gap and interference values of gear set caused by geometric errors can be solved by these geometric models above.Furthermore,based on the rigid geometry models,the node-to-node precise FE contact model of gear set is established.With 3D machining errors and assembly errors embedded and multi-dimension spring elements regarded as the equivalent of elastic supporting system,the FE models of gear drive system coupled with errors and elasticity are established to solve the elastic deformation.Taking a single-stage spur gear train and a helical one as instance,the influence rules of time-varying meshing stiffness,machining errors,assembly errors,elastic supporting characteristics and comprehensive factors on transmission errors and contact performances are analyzed by quasi-static FEA,under a working condition of low velocity and heavy load.Finally,a gear drive experimental rig is designed.The input rotation angles and output rotation angles are measured by high-precision angle encoders and transmission errors of the system are acquired by data processing,which verifies the simulation models and analysis method.In addition,comparison with simulation results and error analysis are done.The geometry models with errors,FEA models and experimental studies in this paper constitute the research system on the performance of gear drive system.The simulation models and analysis results quantificationally reveal the inherent connections of performance indexes with geometric errors and stiffness characteristics and provide guidances for the precision design and rigidity design of gear drive system.