Structural Design and Spatial Geometric Error Modeling of the Machine Tool for Implant Denture

Implant denture is the most essential method of oral repair, and its processing depends heavily on the precision machining center. Most special denture machine tools do not take into account the requirement of automatic machining of parts. During processing, the parts need to be double-clamped, which changes the geometry of the parts. In this paper, a small special machine tool with seven axes has been developed to realize the automatic processing of implant dentures. Firstly, the processing technology of implant dentures is introduced, and the function of a special machine tool is analyzed. Then, the mechanical structure of the machine tool is established. It has seven moving axes and two cylinders, with the capability of five-axis linkage and combined turning and milling. Uniquely, it has a backside machining unit, which allows the entire automated machining process to be completed after only one clamping. The topological movement chain of the machine tool under different working modes is introduced emphatically. The results show that the machine structure can satisfy the automatic machining process of denture parts. Meanwhile, the spatial geometric error model under each topology is established, which provides a theoretical basis for the error compensation of the machine tools.