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Design of a rubber coupling for railway applications
Blach, Jiří ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
The diploma thesis deals with the design and stress-strain analysis of a flexible coupling composed of individual rubber-textile segments. This concept allows the manufacturer to simplify and unify the production thanks to the ability to use a single segment design for multiple coupling configurations and thus leads to a reduction in costs on the part of the manufacturer. From the consumer side this allows only mechanically or chemically damaged segments to be replaced instead of the entire coupling and saves costs for the potential user. The coupling assembly is primarily designed according to the parameters of intercity electric units and locomotives, however, the individual flexible segments are not limited by this use. When designing a coupling assembly, it is necessary to place requirements primarily on the high safety of all components. The operating mode, in which the relative displacement of the input and output shafts can occur, indicates a relatively wide range of transmitted loads which, if any assembly part is improperly designed, can cause problems leading to temporary putting the entire machine/vehicle out of order. The most critical areas of the assembly include the flexible segments, the bolt connections, the strength of the hubs and the spline joint for torque transfer. Last but not least, the requirements for the non-complex production of components must be taken into account, together with the assembly and maintenance without collision of the components and the necessary tools. In order to verify the above-mentioned requirements, stress-strain analyses are performed simulating the variation of operating load conditions. Due to the reduction of hardware requirements and computational time, together with the absence of experimentally measured data of rubber and PES codes, the flexible segments were modelled at a lower level with a reduced material model favouring the tensile properties of PES cords. However, this reduction provides a more conservative approach, as this use causes higher stresses on the steel components of the assembly. Subsequently, a stress analysis of the splined joint is performed. Due to the absence of specific shaft geometry models of commercial motors and gearboxes, a parallel splines were chosen for this purpose and designed according to the specified maximum torque. The last part of the thesis is focused on verifying the tensile properties of an individual flexible segment.
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