Study On Meshing Stiffness Characteristics Of Cycloidal Needle Wheel Under Lubrication

The transmission accuracy of RV reducer is an important factor affecting the working stability of industrial robot.The meshing characteristic of cycloid needle wheel in RV reducer is the main reason that affects the transmission accuracy.It is necessary to study the meshing characteristics of cycloid needle wheel.The meshing stiffness analysis of cycloid needle wheel is emphasized.Grease lubrication is used in RV reducer,so lubrication factors need to be considered in the study of meshing stiffness.In the meshing process,radius of curvature,entrainment velocity and load are variables,so that meshing stiffness has time variability.Radius of curvature,entrainment velocity and load are the key parameters in calculation of lubrication model.Combined with the principle of contour curve design,the contour curve model of cycloid gear under equidistance modification and shift modification is established,and then the equivalent radius of curvature is calculated.The entrapment velocity is calculated by vector method.According to the initial clearance and elastic deformation,the number and position of gear are calculated,and the load is calculated.By numerical calculation of elastohydrodynamic lubrication,the film thickness distribution was obtained based on the contact film thickness formula proposed by Herschel-Bulkley model.The oil film stiffness of single tooth meshing and the comprehensive stiffness of multi-tooth meshing are obtained.The variation of oil film stiffness and composite stiffness is consistent with different modification.It increases with the increase of modification,and the range of comprehensive stiffness decreases.The meshing becomes more stable.The minimum film thickness decreases first and then increases,and the thinniest point is located at the inflection point of the contour curve.Based on fractal theory,the rough surface model of cycloid wheel is established.The mixed lubrication analysis of cycloid pin wheel drive was carried out.Compared with the smooth condition,the meshing stiffness and comprehensive stiffness are smaller,and the comprehensive stiffness has a larger fluctuation range,and more unstable.The minimum film thickness is smaller.The research results are of theoretical significance and practical value for improving the performance of domestic precision reducer and cycloidal gear modification.Figure 35;Table 1;Reference 69...