Research on the Influence of Charging Oil Conditions on the Axial Force of Hydraulic Torque Converter

The hydraulic torque converter is a critical component in high-power tracked vehicles such as bulldozers or bridge machines. Its axial force has a significant impact on the reliability and load-carrying capacity of the transmission system, which is greatly influenced by the charging oil conditions. To investigate the axial force characteristic of the torque converter and its charging oil effects, a computational fluid dynamics (CFD) method is established by considering inner and outer leakage regions, as well as inlet and outlet channels. Additionally, a novel axial force-testing method is proposed, and the axial force testing and validation experiments on the torque converter prototype have been completed. The research findings reveal that changes in oil viscosity resulting from variations in charging oil temperature have a considerable impact on the axial force of the torque converter. The axial force of the pump and turbine decreases as the temperature increases due to varying pressure sensitivity among different components. The influence of charging oil pressure on axial force follows a linear relationship, with its magnitude determined by the axial unbalanced area of the hydraulic torque converter during its design and development. In addition, a formula for the axial force of the hydraulic torque converter is proposed under different charging oil pressures. Furthermore, a novel suppression of axial force has been proposed without altering the structure, which has been validated as an effective method. The results lay a theoretical foundation for the research and suppression of axial forces in hydraulic torque converters, and they also have an engineering application value in the design of high-reliability and long-life converters.