Multilayer Cylindrical Interference Connection Design Method And Experimental Study

A interference fit is a semi-permanent assembly system that can transmitaxial force or torque between two components through the creation of highradial pressures at the interface of its constituent parts. It has the advantages ofsimple structure, low cost, good neutral, strong bearing capacity and is widelyused in industrial production. The interference connection is divided intocylindrical interference connection and conical interference connection.Multi-layer cylinder shrink fit which uses cylindrical interference connectionand conical interference connection, combine the advantages of both, is moreand more applied to engineering.Based on the assumptions of the thick-walled cylinder theory and planestress-strain state, with wind turbine shrink disk as the research object, therelation between the amount of multilayer cylindrical interference fit and contactpressure of the mating surface was discussed, the calculating formulae of contactpressure and magnitude of interference for multi-layer interference fit have beendeduced, dimension-design method of wind turbine’s shrink disk was also given.The assembly process of wind turbine’s shrink disk was simulated by the finiteelement software ABAQUS, and the results were compared with the analyticalvalue. The performance of wind turbine’s shrink disk was verified by statictorque load test. The main content of this research are as follows:Firstly, the relation between the magnitude of interference fit and contactpressures was established by the deformation formulae of thick-walled cylinderand the deformation compatibility equation of wind turbine’s shrink disk, andthe calculating formulae of contact pressure and magnitude of interference wereobtained. Then, the equivalent stress formulae of various components werederived based on the fourth strength theory. Dimension-design method of windturbine’s shrink disk was given combined with dimension driving formulae. Moreover, the formula of outer ring’s pressing stroke was given.Secondly, two-dimensional axisymmetric model was established by usingthe finite element software ABAQUS with the dimensions of some type windturbine’s shrink disk, which was designed based on the calculating formulaabove, and the dynamically-simulated interference assembly was carried out.The results of contact pressure on the mating surfaces and Mises stress of eachcomponent by both methods were discussed. Furthermore, the influences ofmachining deviation and assembly clearance on contact pressure, Mises stressand bearing behavior of wind turbine’s shrink disk were analyzed.Finally, working principle of the static torque load test bench, assemblysteps and experimental steps for wind turbine’s shrink disk were introduced. Inorder to verify the reliability of the design method, loading test of wind turbine’sshrink disk which designed by the method above was carried out by hydraulicjacks in ascending order of loading. Experimental results show that the bearingtorque of wind turbine’s shrink disk reaches working demands.