Abstract: In space geometric error modeling for machine tool of arbitrary structure, the motive axes error transfer chain must be obtained, which is used to finish error modeling based on differential transformation for machine tool of arbitrary structure. By using the theory of multi-body system, the topological structure and low body array for machine tool of arbitrary structure is established. Then by making use of the topological structure and the low body array of machine tool, the concepts of relative motion matrix of supporting parts connected by motive axes of machine tool and connected matrix of supporting parts are proposed and the mathematical model of acquiring error transfer chain of motive axes is built. This mathematical model combines the low body array describing the topological structure of machine tool and the relationship of relative motion of supporting parts of machine tool, which gives the modeling method on acquiring the motive axes error transfer chain of arbitrary machine tool. Additionally, error transfer chain of motive axes obtained by this modeling method is used in space geometric error modeling for machine tool based on differential transformation to realize the space geometric error modeling for machine tool of arbitrary structure. The modeling method’s validity of motive axes error transfer chain is verified by examples of five-axis vertical machining center.

Key words: differential transformation, error transfer chain, multi-body system, machine tool of arbitrary structure