Purpose

This paper aims to provide a precision assembly method to improve the aircraft engine quality of initial unbalance with the purpose of founding the process for mass eccentricity propagation and demonstration of assembly process. The proposed method can be used for assembly guidance, tolerance allocation and so on, especially for the assembly with a large number of rotors and the assembly requirements of initial unbalance and coaxiality in high precision.

Design/methodology/approach

This paper proposes a constrained optimization-build method to minimize initial unbalance of aircraft engine assembly, which takes amount of unbalance and concentricity of each rotor into account. A constrained nonlinear programming model is extracted by choosing the initial unbalance as the objective function, and choosing the coaxiality and assembly orientations as the nonlinear constraints. The initial unbalance is reduced stage-by-stage by controlling the assembly angle of each rotor.

Findings

The validity and accuracy of the proposed method is verified by the multistage rotors assembly through experiments run with the measuring instruments. Compared with the direct-build method, the initial unbalance of final assembly using proposed method is reduced by 22.2% in four rotors assembly.

Originality/value

Different from the geometric eccentricity propagation control methods to reduce the initial unbalance indirectly, this paper establishes mass eccentric propagation model in multistage rotors assembly of aircraft engine for the first time. It provides a new idea to establish the relationship between the amount of unbalance of each rotor and the initial unbalance of multistage rotors.

中文翻译：

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一种新型的飞机发动机精密装配约束优化制造方法

目的

本文旨在提供一种精确的组装方法，以改善飞机发动机初始不平衡的质量，从而建立质量偏心传播过程并演示组装过程。所提出的方法可用于装配指导，公差分配等，尤其适用于具有大量转子的装配以及对高精度初始不平衡和同轴度的装配要求。

设计/方法/方法

本文提出了一种约束优化-构建方法来最小化飞机发动机组件的初始不平衡，该方法考虑了每个转子的不平衡量和同心度。通过选择初始不平衡度为目标函数，并选择同轴度和装配方向为非线性约束条件来提取约束非线性规划模型。通过控制每个转子的组装角度，可以逐步减少初始不平衡。

发现

通过使用测量仪器进行的实验，通过多级转子组件验证了所提方法的有效性和准确性。与直接构建方法相比，采用建议的方法的最终组装的初始不平衡减少了4个转子组件中的22.2％。

创意/价值

与间接减小初始不平衡的几何偏心传播控制方法不同，本文首次建立了飞机发动机多级转子总成的质量偏心传播模型。它为建立每个转子的不平衡量与多级转子的初始不平衡量之间的关系提供了新的思路。