Abstract: Aiming at the problem that the transmission efficiency of hydraulic torque converter changes according to the change in load, an adaptive high-efficiency hydraulic torque converting transmission system is put forward. A magnetic powder clutch is added between engine and hydraulic torque converter in order to change the transmission system from single-stream transmission to dual-stream transmission, so that the engine provides torque to the input shaft of gearbox via magnetic powder clutch when load increases and transmission efficiency drops, thereby changing the speed ratio of hydraulic torque converter and making it work at its maximum efficiency running point. The calculation formula of transmitted torque of magnetic powder clutch and efficiency of transmission system are given, which provides reference for design of adaptive high-efficiency hydraulic torque converting transmission system. The calculation result of an example shows that the transmission efficiency of high-efficiency hydraulic torque converting transmission system proposed can be increased by an average of around 4.6%.

Key words: High-efficiency, Hydraulic torque converter, Magnetic powder clutch, Transmission system, Air rarefaction, Asperity contact, Startup process, Precision H-type air bearing