Traction systems for passengers rail cars - The diesel-hydraulic transmission an alternative for the Brazilian market

摘要

Three traction systems are the most well known and successful for passenger rail cars: the electric traction system with choppers or more moderns with VVVF inverters that controls cc or ac traction motors, the energy is collected via catenaries or a third rail. In the diesel-electric (DE) system an engine-generator group is used to generate the necessary energy to the choppers or inverters. And in the diesel-hydraulic (DH) system the diesel engine is connected to an automatic transmission that converts the torque using the hydrodynamic principle of Fottinger, in this system the torque is transmitted to the wheels by the transmission through a cardan shaft and final drivers connected to the axles. A hydrodynamic converter of Fottinger is composed by a turbine wheel and a pump impeller - both involved by a guide cover. The force transfer occurs with a very low wear out once there is no mechanic contact of the wheels. In the automatic transmission the impeller is connected to the diesel engine. The content of this publication goes back to the 3 week "Hydraulic" seminars held for the new generation of recruits to the spring of 2001. This should be extended to an overview of the fundamentals of Hydrodynamics. After the Hydrodynamic circuit the development of the Turbo Transmission and its primary and secondary characteristics will be reviewed. In the end some applications in railcars, it's advantages and some innovation for the future.