Improvement of location and orientation tolerances propagation control in cylindrical components assembly using stack-build assembly technique

This paper aims to provide an assembly method to improve cylindrical components assembly quality. The proposed method not only could be applied to tolerance allocation, but also could guide the assembly of cylindrical components.

The paper claims to provide a stack-build assembly method using a connective assembly model to take the location and orientation tolerances of a rotor stage into account. Through the separate analysis of the location and orientation tolerances propagation process in the assembly, the quality of the final assembly of the rotationally symmetric cylindrical components assembly could be improved by properly selecting component orientations to minimize the eccentric deviation in the assembly.

The effectiveness of the proposed stack-build assembly technique in improving the tolerance propagation in the assembly of cylindrical components was verified through experiments run with a measuring machine. A real aero-engine rotor was assembly using the proposed method; compared to the direct-build assembly technique, which had the component orientations without consideration, the stack-build assembly technique could be used to reduce the eccentric deviation in cylindrical components assembly by nearly 50 per cent.

Different with the old methods, the new method defined the tolerances in detail, such as perpendicularity and angle of the lowest point, and could guide the assembly by the features of surfaces on different components. Through measuring the special tolerances of surfaces on the components, the best assembly angle for each component could be obtained.