Measurements error propagation and its sensitivity analysis in the aero-engine multistage rotor assembling process

The purpose of this paper is to research the measurements error propagation principle about the measurement-assembly equipment of aero engine multistage rotor, besides analyze the effect of guide linear motion and turntable rotational motion on the final alignment error. Furthermore, we can improve the measurement and assembly accuracy of the aero engine multistage rotor. In this paper, a novel error analysis method related to measurement-assembly equipment was proposed. First, the topology of the measuring equipment was established based on the multibody system theory, the error propagation path was constructed by using the low order body sorting method. Second, the error transfer model of the linear motion and the rotational motion were established by using the homogeneous coordinate transformation matrix, and the total measurement terminal errors introduced by the equipment were calculated. Finally, through numerical simulation, the magnitude of the measurement terminal offset error was obtained, sensitivity analysis was performed to calculate key error sources. Measurement accuracy not only depended on the accuracy of the sensor but also closely related to the accuracy of the measurement-assembly equipment. Through the simulation verification, when the linearity error is 0.1 μm and the angular error is 0.1″, the final cumulative offset displacement error is about -0.1002 μm to -0.0998 μm with a probability of 97%. Different type errors have different effects on the results. We can give a conclusion that linear guide alignment error and verticality error are the primary error sources, and the angle error of the turntable need to be improved.