Optimization and type selection for compound transmission with continuously variable characteristic parameter
The core technology of the composite transmission system is matching.Based on the actual importance and adaptability of each evaluation index in different composite transmission systems,the optimal scheme is selected from all possible applicable power split schemes to complete a complete optimal selection design.In order to avoid the problem that the excellent scheme is missed,the speed ratio and torque of 12 composite transmissions are analyzed firstly,and then proposes 3 torque coefficients at different key places in drive line which are selected according to torque capacities of components.Secondly,with the range of speed ratio and 3 torque coefficients as objective functions,a non-dominated genetic algorithm-Ⅱ(NSGA-Ⅱ)is applied to optimize two fixed gear ratios of gear pairs,the comprehensive optimal state of the 12 classic compound transmissions is obtained.Lastly,according to the importance and adaptability of evaluation indicators,a multi-step pre-ranked selection method for compound transmission with continuously variable characteristic parameter is proposed,and an integrated design process with optimization and type selection is conducted.Compared to the pre-optimization systems,the speed ratio range is increased by 24%,the maximum output torque is increased by 18.92%,and the efficiency is increased by 2.25%.