Voith Turbo-Transmissions - Setting Performance Standards of Turbo-Transmissions

Setting Performance Standards of Turbo-Transmissions

The operating conditions of rail vehicles are the key factors in determining the power requirements of both its motors and transmissions. These operating conditions cover: hauling loads for diesel locomotive, passenger capacities for diesel railcars, the topography of the rail line, and the climatic conditions when the vehicle is operated outside of Europe. The expected operating conditions are part of a vehicle's technical requirements and determine the follow points:

1. Maximum speed
2. Acceleration rates during start-up in consideration of the frictional resistance of all motorized wheel-sets in multicar trains
3. Acceleration rates when in transit to avoid traffic jams in metropolitan areas where predominantly electric railcars are also in operation
4. Minimum speed which can be maintained over long distances
5. Dynamic braking requirements when travelling at high-speeds and/or over long descents due to its economical operation

Maximum speed, vehicle weight, acceleration rate and the railway slope all influence a motor's performance specifications. Added to that, the requirements of the auxiliary systems also need to be considered, such air-conditioning units, motor cooling systems, brake compressors and in some cases the need for a separate power supply to run the air-conditioning and heating systems of each passenger car. Here, a range of diesel motors can be selected, from large frame V-motors for locomotives to flat 6-cylinder sub-floor motors for motorized railcars or even the compact 12-cylinder motors often used by utility vehicles. For most modern motorized railcars, the preferred solution is a sub-floor mounted motor and transmission combination.