Transmitting Torque Calculation of the Rotary Blade Coupling for 4wd Vehicles

Abstract

The Rotary Blade Coupling (RBC) is a type of torque split couplings for 4-Wheel Drive (4WD) vehicles. RBC unit mainly consists of a wet multi-disk clutch and a pressure chamber with the blade rotating in high viscosity silicone oil. The pressure chamber generates clutch engaging hydraulic force, which depends on the differential speed between the input and the output shaft. The high viscosity silicone oil in the pressure chamber exhibits non-Newtonian fluid properties. This report presents the simplified flow analysis as the practical designing tool. Effects of non-Newtonian fluid properties of silicone oil are considered. Also the heat transfer modeling during the coupling operation is included in the calculation. Typical blade shape calculations and the experimental results to insure the analysis are shown.