| RV reducer is a high-precision reducer mainly used in robot joints.It has the advantages of large carrying capacity,large torsional stiffness,long life,high reliability and smooth operation.As the core component of the RV reducer,the cycloid gear is theoretically half of the needle teeth involved in the meshing.However,in actual engineering applications,in order to make up for manufacturing and installation errors and reserve a reasonable gap to form an oil film to ensure lubrication and convenient disassembly,it is necessary to modify the cycloid gear.The modified cycloidal pin gear drive effectively avoids the phenomenon of tooth jamming,reduces the impact of meshing-in and meshing-out,and improves the meshing performance.At the same time,the meshing stiffness of the cycloidal gear pair,the number of meshing pin teeth,the force of the pin teeth and the dynamic excitation will have great changes,which are the key factors affecting the bearing capacity,vibration,noise and dynamic characteristics of the transmission system of the RV reducer.Therefore,research on the influence of cycloid tooth profile modification on the dynamic characteristics of RV reducer has important theoretical guiding significance and practical engineering value for RV reducer vibration and noise reduction.This paper takes RV reducer as the research object,carries out cycloid tooth profile compound modification,time-varying meshing stiffness calculation,internal dynamic excitation analysis,transmission system dynamic characteristics research,vibration response simulation analysis,radiation noise prediction and compound modification parameters Optimization research.The main research contents are as follows:(1)Deduction of cycloid tooth profile equation based on meshing principle,and the mechanical characteristics of the cycloidal transmission and the crankshaft considering the eccentric error are analyzed.The influence of different cycloidal profile modification methods and modification parameters on the mechanical properties is analyzed and discussed.Research on the calculation method of the optimal modification parameters of the cycloid wheel considering the crankshaft eccentricity error.(2)The calculation method of the meshing stiffness of the cycloidal gear pair considering the modification of the cycloidal tooth profile is deduced.Considering the time-varying meshing stiffness,meshing damping,comprehensive error,meshing impact,bearing stiffness and damping,etc.,the dynamic model of the RV reducer transmission system is established by the lumped parameter method,and the dynamic characteristics of the transmission system are solved and analyzed.(3)Based on ANSYS software,a finite element model including cycloid gears,needle rollers,internal gears,sun gears,planetary gears,bearings and other components that consider the compound modification of the cycloidal tooth profile is established.The modal analysis of RV Reducer is carried out,and its vibration response is solved based on modal superposition method.The acoustic calculation model is established based on the frequency domain response analysis results of vibration displacement on the outer surface of RV Reducer as boundary conditions.The direct boundary element method is used to estimate the noise,and the vibration response and radiation noise of the RV reducer before and after the modification are compared and analyzed.(4)The influence of modification on meshing stiffness and vibration response of cycloid gear pair is analyzed.Take compound modification parameters as design variables and low meshing force as the goal to optimize the compound modification parameters of cycloid tooth profile.The mechanical characteristics,meshing stiffness,vibration and noise of the cycloid gear pair before and after optimization are compared and analyzed. |
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