Exact Solutions of Interference Fit of a High-speed Coupling for Micro Gas Turbine

Interference fit is widely uesd in the high-speed coupling of micro gas turbine since it can transfer large torque, are easy to produce and offer significant cost advantages. In this paper, a interference fit model was developed to analyse the contection strength of coupling and shaft for micro gas turbine. Then using elastic theory, the radial stress, tangential stress and radial displacement of high-speed coupling are derived with taking account of contact pressure, angular velocity and the thickness of coupling. Finally taking a 100kW micro gas turbine as an example, the above solutions were calculated by using the numerical method and results show that the contact pressure, angular velocity and thickness of the coupling, should be considered for the design of the interference fit between the coupling and shaft in micro gas turbine. The direction of the radial stress of the coupling is determined by the value of the contact pressure. The tangential stresses of the coupling are identically greater than zero. The radial displacement of the coupling is a monotony decrease function of the radius and positively correlated with the contact pressure, angular velocity and thickness of the coupling.