Multistage rotational optimization using unified Jacobian–Torsor model in aero-engine assembly

Abstract

For revolving components like compressor stages in aero-engine, it is critical to ensure that the overall concentric performance of the assembly is extremely excellent to satisfy the requirements of vibration-free and noise-free. However, in practical production, it is hard to meet the target requirement by manual adjustments; in virtual assembly, it is difficult to build an effective deviation propagation model with traditional methods. This article focuses on two points: one is the assembly technique of multistage rotational optimization and the other is the deviation propagation model for revolving components assembly. The revolution joint was introduced in the unified Jacobian–Torsor model to provide the rotary regulating effects. This modified model has advantages of being able to consider rotating optimization, geometric tolerance, and percentage contribution compared with other mathematical methods. General formulas for the n-stage components assembly were derived including the deviation propagation function and optimization destination expression. Comparisons between three assembly techniques and experiments were made to prove the suggested method was feasible and of high practicability. It can be integrated with computer-aided design systems to propose assistance for operators in assembling stage or redesign parts tolerances where FEs’ percentage contributions can be obtained in design preliminary stage.

Assembly research of aero-engine casing involving bolted connection based on rigid-compliant coupling assembly deviation modeling

“…Herein, the deviation of the geometrical feature is set from the minimum to maximum in the tolerance zone. Then, the value of the vector in the Torsor model is expressed as a tolerance interval, and the corresponding Jacobian-Torsor model (original model, O model) is written in equation (22) where (, ) means a tolerance interval, and are the minimum and maximum respectively, other vectors follow the same way. Herein, FR is calculated through the multiplication formulation of Jacobian matrices and torsor matrices.…”

“…Considering that the traditional Jacobian-Torsor model is just about the rigid assembly with manufacturing tolerance, and has no concern about the compliant assembly in casing, herein, the torsor expression of the Jacobian-Torsor model in the previous studies 21,22 is modified as follows to improve its suitability for compliant assembly…”

“…Chen et al 21 addressed the tolerance boundary issue and the constraint among different vectors. Then, Ding et al 22 studied the multistage rotational assembly about the aero-engine rotors and provided the optimal rotational angle of each rotor. The result showed an efficient and innovative method to analyze the concentricity deviation of engine rotors.…”

“…However, the relevant tolerance investigations about aero-engine mainly focus on the rotor of the aero-engine, 17,18,22 and considered assembly quality without any compliant deformation. The existing researches involved in the aircraft engine casing were almost about the vibrational and mechanical behaviors.…”

An assembling algorithm for fixture in an assembly process planning system

“…Therefore, the development of assembly technology is an important method of guaranteeing the quality and function of products, which is of great significance in improving the product quality and reducing the cost and time of the design cycle. 2…”