Research On Dynamics Optimization Design For Encased Differential Planetary Gear Train

With modern gear transmission technology develops towards heavy-speed and overloadingrapidly, the requirement of dynamic performance become more and more high and traditional designmethod is difficult to meet the requirements of design. Considering the influence of dynamic factorsin the design stage and predicting the gear dynamic performance is particularly important. Thedynamic load characteristics of gear transmission system has a great impact on the dynamicperformance and working reliability of the system. In this paper, we make a research on the dynamicsoptimization design based on the dynamic load characteristic of the differential and the closedplanetary gear drive system.Based on the lumped parameter method, the dynamics analysis model is given for the differentialplanetary gear transmission system. The model includes the time-varying mesh stiffness and otherparameters such as damping, gear eccentric error and external incentives and so on. Installation errorand manufacture error of eccentric error are contained in the eccentric error of the gear, we gain theformula of the equivalent meshing error, the displacement of the center are equivalented to be thedisplacement of the corresponded meshing line. According to the Newton’s second law, we can obtainthe dynamics balance equation of the differential planetary gear transmission system. By eliminatingthe rigid body displacement of the system and the dimensionless method, we solve the equation byusing4-5order Runge-Kutta numerical integral method and get the inherent characteristics and thedynamic load coefficient, we also analyze the influence of the error and the support stiffness or othersystem parameters on the maximum dynamic load coefficient of the system.Based on the dynamics solution of the differential planetary gear transmission system, dynamicsoptimization design of the system was carried out. We can choose the reasonable optimization designvariables and constraints by analysising and researching. We proposed dynamic load coefficientdeviation between calculated and the rate one as the objective function and use the fmincon functionin MATLAB to solve the issue. In addition, two more optimization design scheme was proposed toguide practice more comprehensive and reasonable. We also analyze the influence of the input speedand power on the objective function, providing reference for rational selection of conditions. Theinfluence of the optimal design variables on the result of optimization are analyzed in the last.Research shown that the effect of the dynamics optimization design is obvious, providing a reliableand effective design method for the gear transmission system dynamics optimization design of designvariables and constraints.The study of dynamics optimization design for closed planetary gear transmission system wascarried out. Based on the current research of dynamic load characteristics for closed planetary geartransmission system, we can choose the reasonable optimization design variables and constraints. Weproposed dynamic load coefficient deviation between calculated and the rate one as the objectivefunction and use the fmincon function in MATLAB to solve the issue. Two more optimization designscheme was proposed and the influence of the optimal design variables on the result of optimizationare analyzed. Research shown that the effect of the dynamics optimization design is obvious. In theoptimized design scheme, the effect of design variables on the result of optimization is different whichneed specific concrete analysis.According to the result of the theoretical analysis and actual demand, using the MATLAB software as a platform, we can develop a set of engineering analysis software in regard to thedynamics analysis and dynamic optimization design of the differential and closed differentialplanetary gear transmission system.