Heat Balance Calculation Of Torque Converter And Cooling System Design

Torque converter is a load change mechanical device by hydraulic transmission. It has good automatic adaptability. It can simplify the vehicles control, accelerated rapidly started smoothly.It has a wide range of applications in engineering machinery industry, but its ability is influenced deeply by thermal characteristics. If the hydraulic transmission oil temperature is too high, the heat can not be dispersed in time, the transmission oil will turn bad, has lower volumetric efficiency, the system will occur early failure of seal leakage, reduce the transmission characteristics and components of early damage etc. Conversely, if the heat capacity of cooling system is too strong, make the oil temperature too low, the torque converter also cannot get the best hydraulic transmission characteristics. Therefore, accurate estimation heat capacity of the system and configure reasonable parameters in the design phase can improve the performance of the car.In this paper, the theoretical basis of heat transfer, hydraulic torque converter work on energy loss in the process of heat production were analyzed, obtained torque converter heat production formula. In this process, using Matlab software to build mathematical models to calculate the engine with the torque converter input characteristics under different conditions, in essence, is the net engine torque characteristic curve and hydraulic torque converter pump torque characteristic curve round a series of intersection. Obtained under different conditions torque converter pump wheel torque and speed, you can get the corresponding input power, and by heat calculation formula under different conditions of heat torque converter, obtained the heat balance equation the need for heat dissipation cooling system finally. This article use the D400 Torque Converter for example, input the parameters of engine and Torque Converter to calculate the heat of Torque Converter, analysis of the typical operating conditions (different speed ratio):Starting Condition,speed ratio is 0; the high efficiency, efficiency in the 0.75 to 0.8; the most efficient condition; no-load conditions, when the maximum speed ratio; coupling conditions and other specific circumstances, the final selection of a specific working conditions heat as the basis for design of cooling system. In the cooling system designing process, the traditional program and the current lack of improvement on the traditional cooling system were analyzed. Then designed the cooling system solutions of D400 torque converter. Through calculating the heat capacity radiator, cooling air circulation through the required amount of fan power consumption, heat sink area and electrical power and other thermal parameters, selected the main components of the cooling system selection and completed the overall design finally.