Assembly Accuracy Prediction And Stacking Of Aeroengine Rotor

Assembly is a very important part in the manufacturing process of aero-engine rotors.In order to ensure that the coaxiality of the rotor after assembly meets the requirements and reduce the vibration of the whole machine,it is necessary to select the assembly process parameters reasonably.At present,the rotor assembly of China mainly dependents on the ‘trial and error’ and repair afterwards.Due to lacks of assembly mechanism support,the current method is not only inefficiently assembled,but also very likely to cause a "bow-bow" rotor,which causes vibration and reduces engine life.Therefore,it is very important to study the quantitative relationship between the rotor’s own parameters and the coaxiality of the assembled components,and test the assembly accuracy of the rotor before the rotor assembly and make some adjustments in time.In this paper,the prediction method of rotor assembly concentricity and relative axis deflection error is proposed considering the influence of coaxiality for sovling the prediction and stacking problem of aeroengine high-pressure rotor assembly accuracy.The prediction and stacking model of assembly precision are established based on the principle of homogeneous coordinate transformation.The principle rotor test piece is designed and processed to carry out single-stage and multi-stage rotor assembly tests to verify the prediction results of the model.The main research contents of this paper are as follows:(1)The face runout and radial out of the single-stage rotor are measured.The circular contour measurement model considering multiple error source elimination which is based on the Limacon model is used to eliminate the measurement error,and then the experimental data is filtered.(2)Two kinds of prediction methods for concentricity are proposed by analyzing the factors affecting the coaxiality in the assembly of rotor components,including a filter fitting method based on a conventional fitting circle method and an elastic force method considering an elastic deformation of an interference spigot.Two prediction methods for the relative axis deflection error of rotor assembly are proposed,including a three-point contact method based on centroid driving,and a method considering the elastic deformation of a flange surface.(3)The accuracy prediction stacking model of aero-engine component assembly is established by the principle of homogeneous coordinate transformation combined with the proposed eccentricity deviation prediction method which is characterized by the Small Displacement Torsor(SDT)theory.And then the influencing factors of the model is analyzed in details.(4)Based on the experimental results of multi-stage rotor assembly,the standard value of the eccentric deflection of the component axis is calculated.By comparing with the prediction results of the assembly accuracy prediction stacking model proposed in this paper,it is concluded that the prediction model has low relative error and good prediction effect,which has assembly guidance significance.