Research on intelligent assembly method of aero-engine deep-cavity nuts based on torque-angle control.

Area of Science:

• Aerospace Engineering
• Mechanical Engineering
• Materials Science

Background:

• Aero-engine low-pressure rotor high-torque nut assembly is critical for operational reliability.
• Deep cavity assembly presents challenges in meeting torque, angular accuracy, and preload control requirements.

Purpose of the Study:

• To develop an optimized assembly method for high-torque nuts in aero-engine rotors.
• To create a visual tightening system integrating monitoring and servo control for improved assembly quality.

Main Methods:

• Integration of fractal contact mechanics (Weierstrass-Mandelbrot function) and multi-physics coupling.
• Development of a visual tightening system with servo control.
• Establishment of a thread stiffness model and use of ANSYS simulations for thermal-centrifugal coupling analysis.

Main Results:

• Surface roughness (Ra=1.6 μm) limits real contact area to 12%-18%.
• Thread stiffness model shows <1% error; simulations quantify preload attenuation.
• Developed system achieves [Formula: see text] angular accuracy and controls preload error within [Formula: see text].

Conclusions:

• The optimized method and visual tightening system meet stringent aero-engine assembly requirements.
• Assembly time reduced by 35% (from 4 to 2.6 h) with improved efficiency and collision avoidance.
• Enhanced system ensures high-reliability assembly for aero-engine operational safety.