Rail drives (MBS)
Full title: |
Rail drives (MBS) |
Contributor: |
Dr.-Ing. Thomas Rosenlöcher (TU Dresden, IMM) |
Objective: | The contact conditions between train wheel and rail can be described for the dynamic driving simulation of rail vehicles by complex theories with varying degrees of detail. Based on many years of experience with commercial simulation programs, the analysis of different driving conditions of rail vehicles are an integral part of the product development process. In order to consider the detailed information to the effective dynamic forces in the wheel-rail contact within the development of gearboxes used between engine and wheel-set, multibody system simulation enable the assembling of complex overall models. These models combine the detailed representation of the contact condition between wheel and rail, the gearbox components, the electric drive and the control. By varying the control parameters and the comparison with natural frequencies of the system, different influencing variables can be shown which can lead to an increase of loads in the gearbox. |
Approach: | To extend a model for the dynamic driving simulation to the complete electro-mechanical overall model, the gearbox is additional modelled between the input shaft at the engine side and the hollow shaft as connecting element to the train wheel shaft. The engine drives via a pinion shaft the two-stage gear chain, which is connected at the last wheel by a shaft with an axial displaced double-helical gear pair. This tooting transmits the drive torque to the hollow shaft mounted in the housing. To decouple the weight of the transmission from the actual wheelset and to reduce the unsprung masses of the wheelset, the further transmission of the torque occurs by an elastic link coupling. |
Results: | The performed investigations demonstrate significant dependencies between the loads on the gearbox components and the conditions in the wheel-rail contact as well as the control of the electric motor. The relation cannot be formulated as a general statement but may need to be analysed for each application. By the consideration of detailed gearbox models into complex simulation models of the wheel-rail contact, the interactions between the two systems and the control of the electric motor can be analysed. This may result in loads, which are disregarded in the assumed nominal loads. Especially for the definition of load assumptions or for the determination of control parameters during the development, electro-mechanical models for dynamic driving simulation can provide helpful information. |