Model for evaluating the end runouts of a rotor with parallel connections of parts

Abstract

The existing methods for calculating the assembly dimensional chains of aircraft engine rotors are analyzed. The factors that have a significant impact on the reliability of the calculation of the controlled assembly parameters of the product are identified. One of these factors is the existence of parallel connections of parts in the rotor. In the drum disk rotors, parallel rotor connections are formed by mating their parts along several end surfaces in the axial direction. A mathematical model is proposed that allows taking into account the parallel connections of the rotor parts. The form of relationship between rotor end run-outs and amplitudes of deviations of the shape of the mating surfaces of the parts and their angular positions in the unit is determined. The determined dependence includes many coefficients that allow taking into account the amplitudes of deviations of the shape of the mating surfaces, parallel connections of parts in the rotor, and their angular position. Determination of dependence coefficients values is solved as a problem of regression analysis. The initial data for obtaining the dependence are formed using the developed parameterized finite element model (FEM) of a part of the rotor of an aircraft engine high-pressure compressor (HPC). The results of research of end run-outs of control surfaces of disks of the considered HPC rotor assembly part are presented. The values of the dependence coefficients for assessing the end run-outs of the rotor are determined.

Keywords

• mathematical model
• parallel connections of parts
• finite element model
• prediction error
• surface profile and surface position deviations
• regression dependence