Stress and Displacement Distribution of High-speed Coupling and Shaft for Interference Fit

Micro gas turbine, which can not only be applied for distributed power supply, but also be used as auxiliary power device of mobile power station, is widely used in industry, civil and other fields. Generally, it is composed of compressor, turbine and generator which are coaxial connected by couplings and have the same rotational speed, so the high-speed coupling is important to the micro gas turbine. Interference fit, which is widely used in flexible coupling, can transfer large torque while avoiding unbalance. Thus, the aim of this paper is to analyze the load capacity of the for various structure and working conditions to ensure stable and reliable operation of the micro gas turbine. The equilibrium differential equations are rewritten under the high-speed condition and the boundary conditions are rewritten under the torque transfer condition. Then the stresses, displacements and the magnitude of interference of the coupling and shaft are studied. The numerical calculation results show: the couple effect of the contact pressure for the torque transmission and angular velocity play an important role in analyzing the load capacity of the high-speed coupling and shaft. It is a sound alternative to use the thin-walled coupling in the micro gas turbine because it can produce less centrifugal force and unbalance quantity and ensure the load capacity.