| dc.description.abstract | A turbine shaft end at the coupling is exposed not only to constant torque load but to various variable loads as well. These externally imposed variable loads come from sources like compressor surge, misalignment between turbine shaft, and the driven machine, to name a few. These loads can be bending or torsional in nature. To assure reliability, the design method should include the influence of such loads on the final sizing of the shaft end. The design method should also include the effects of shrink fits, keyways, fillets, chrome plating and fretting on the fatigue properties of the shaft material.
Due to variable nature of loads superimposed on the steady torque load, the design method must be based on fatigue behavior of materials. Many fatigue theories have been used in the design of components of turbomachinery. These depend on the nature of the load, type of material and component being designed. A designer should realize not only the nature of loads imposed on the .shaft and their source but also have an estimate of the magnitude of those loads. A design method is described which includes many of the factors governing the useful life of the shaft at the coupling end. This method is based on the von Mises reliability criteria, including the influence of the driven machine and the choice of coupling type. This design method has resulted in many successful designs throughout the years and has helped in selecting a less costly but reliable option in many rerate situations. | en |
