| The deceleration bearing based on the principle of planetary traction transmission realizes power transmission and lubrication through the oil film.It has the function of deceleration and can provide support in the transmission system.Its compact structure and small volume,stable transmission and low noise,has a very good application prospect.However,the current research on the deceleration bearing is still shallow,and due to the lack of a reasonable axial limiting method,it will cause a large friction loss when it receives an axial force,which will reduce its transmission efficiency and supporting effect.Because of these problems,the structure of the planetary traction deceleration bearing is improved.The new deceleration bearing has a simple structure,can withstand axial forces stably,and the axial space is more compact,which improves the power density and weight reduction effect of the in-wheel motor assembly to a greater extent.In addition,this subject analyzes and calculates the performance of the deceleration bearing from many aspects,and the results have important reference value for future research on planetary traction deceleration bearings.The main work content is as follows:(1)Establish an improved planetary traction deceleration bearing structure model,and conduct assembly process research on the new structure;give the working principle of the planetary traction reducer bearing and the calculation method of the required pressing force;propose the optimal design method and dynamics of the planetary traction reducer bearing time-varying elastohydrodynamic lubrication research method.(2)In order to make the radial deformation and axial length of the planetary traction deceleration bearing as small as possible,the subject is based on FEA technology and NSGA-Ⅱ multi-objective optimization method for the planetary gear and outer ring wall thickness,input shaft interference and contact pair length Optimize the design.According to the Hertz contact theory,under the same conditions,the total pressing force has a linear relationship with the length of the contact pair.firstly,the optimal deceleration bearing model per unit contact length with small radial deformation and large linear load is optimized and designed;secondly,the different contact pair lengths are calculated by simulation to determine the final planetary traction deceleration bearing model based on the relationship with the total pressing force and selecting the appropriate length of the contact pair.(3)To verify the dynamic characteristics of planetary traction deceleration bearings,taking the deformation of the planetary gears and outer ring during the working process,the ordinary multi-rigid body dynamic analysis is not suitable for the dynamic analysis of deceleration bearings.Therefore,this subject combines the ADAMS rigid-flexible coupling dynamics simulation technology and the ABAQUS FEA module to generate a flexible body model,and establishes a rigid-flexible coupled multi-body dynamics model for planetary traction deceleration bearings.The radial vibration of the shaft is very small,and it has good smoothness.(4)Combining the theory of non-Newtonian fluid time-varying elastohydrodynamic lubrication and the transmission mathematical model of planetary traction reducer bearings,a mathematical model of time-varying elastohydrodynamic lubrication characteristics of non-Newtonian fluids in the working process of deceleration bearings is established and the MATLAB numerical calculation program is written.The calculation process uses Multigrid method and Gauss–Seidel iterative method.Based on the two working conditions of acceleration and load fluctuation,the time-varying elastohydrodynamic lubrication characteristics of the contact pair of the inner ring shaft and the planetary gear at different slip-roll ratios are first analyzed,and then the time-varying deceleration bearing model under different slip rates elastohydrodynamic characteristics are analyzed. |
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