Optimal parameters design method for power reflux hydro-mechanical transmission system

Abstract

To ensure the starting torque ratio while improving the efficiency of the automatic transmission system, a power reflux hydro-mechanical transmission system which consists of a torque converter, a planetary gear, and two gearboxes is proposed. First, the properties of the speed ratio, torque ratio, efficiency, and capacity in the power reflux hydro-mechanical transmission system are modeled. Then, the non-dominated sorting genetic algorithm II is used to optimize the structural parameter of the planetary gear and the speed ratio of the gearbox T1, with the speed ratio width in the high-efficiency area, efficiency, and power performance acting as target functions. Moreover, the method of selecting the specific torque converter for the power reflux hydro-mechanical transmission system is proposed. Results show that the starting torque ratio of the power reflux hydro-mechanical transmission system increases to 4.87 and the equivalent efficiency in high-efficiency area of the power reflux hydro-mechanical transmission system reaches to 90.87%. Therefore, the power reflux hydro-mechanical transmission system can reach higher efficiency while ensuring the starting torque ratio compared with hydro-mechanical power split transmission, which can significantly reduce fuel consumption once applied to the construction vehicle.

Analysis and experiment of HMT stationary shift control considering the effect of oil bulk modulus

“…Combining equations (14) and (26), the relationship between the shifting time required for the two brakes and the bulk modulus of the oil is as follows:…”

“…2 In order to improve the power and economy of vehicles equipped with HMT, scholars have done a lot of research on the influencing factors, control strategies, and layout structure. [3][4][5][6][7][8][9][10][11][12][13][14] However, the poor dynamic quality of the HMT during the shifting between different ranges affects its wide application in heavy vehicles. Thus, Ni et al, 3 Zhu et al, 4 and Hu et al 5 analyzed the order of the effects of different physical parameters of the transmission on the shift quality by experiments.…”

“…To solve the above problems, Zhang, 9 Yang et al, 10 and Yin 11 respectively proposed control strategies for the shifting timing and the shifting time of multiple sets of brakes, and the rationality of the strategies was verified by experiments. Irfan et al, 12 Sung et al, 13 and Zhang et al, 14 respectively, used GT-Suite model, network analysis, and genetic algorithm to optimize the structure of HMT, improving the transmitting efficiency of the system and reducing the fuel consumption. However, all of the above studies are based on the mechanical structure, without considering the effect of oil characteristics on the shift quality.…”

Characteristic Analysis and Co-Validation of Hydro-Mechanical Continuously Variable Transmission Based on the Wheel Loader

“…The conventional transmission applied to the wheel loader is the mechanical transmission with torque converter. Therefore, many scholars have studied the traditional transmission with torque converter [1][2][3]. However, the efficiency of the torque converter has a greater impact on the efficiency of the transmission system, which results in no significant increase in efficiency, whatever structure is adopted.…”

Modeling of Power Transition in Full Power Shift of Hydromechanical Transmission

“…Rossetti and Macor [15,16] regarded the design of the input-coupled HMT (using three shaft ordinary gear and a simple planetary gear) as an optimization problem and achieved good results. Sun et al [17][18][19] designed a power reflux hydromechanical transmission based on a torque converter instead of the traditional hydraulic transmission unit.…”