Abstract: For deviation accumulation analysis and mechanical precision predicting effectively and accurately, a sensitivity analysis of assembly deviation source based on multidimensional vector loop is proposed. According to the actual production, deviation source is divided into three types: Dimension deviation, geometric and position deviation, and assembly location deviation. Deviation source sensitivity is defined as the ratio of assembly size variation and deviation source size variation. Assembly joint types are abstracted to six kinds: Planar, cylinder slider, edge slider, revolute, parallel cylinders and rigid. According to assembly constraint relations, assembly sequence and way of positioning, deviation transfer path is established by positioning the join between parts, and establishing part’s datum reference frame. Assembly multidimensional vector loop is created by the deviation transfer path, and scalar equations of each dimension are established. Using the first order Taylor expansion and matrix transformation method, assembly deviation source sensitivity is solved. Taking assembly precision optimization of wing flap rocker as a research example, test the effectiveness and efficiency of the deviation source sensitivity analysis method.

Key words: assembly, deviation source, sensitivity, vector loop