| Roller gear cam mechanism is a type of indexing device. It is widely used in various automatic machines because of large indexing numbers, high indexing precision, reliable localization etc. Because our country studies this mechanism less than America and Japan, the standardization and seriation of the product aren't researched, and the measuring method is studied deficiently. Therefore the author built a 3-D model based on the surface equations of roller gear cam, and presented a method of using coordinate measuring machine (CMM) to measure the surfaces of the cam.The roller gear cam mechanism is studied and the surface equations of various types of roller gear cam are acquired. The theoretic surface coordinates of roller gear cam are calculated with Matlab according to the surface equations and design parameters. The point cloud are converted into surfaces by using software Image ware; the surfaces of basal solid and connecting surfaces between point cloud surfaces are constructed according to design parameters; the point cloud surfaces are snipped with surface edges of basal solid and the model of roller gear cam is completed. The assembly model of roller gear cam mechanism is built by using Pro/E. The problem of how to correct the profiles of roller gear cam is studied.The function of CMM is studied according to the CMM that is owned by Engineering training center. A method of using CMM to measure surface error of roller gear cam is researched. The starting point is confirmed by programming with optimization toolbox of Matlab in order to adjust measuring reference frame to theoretical reference frame. A numerical experiment is designed and the validity of optimization program is proved. The truth of the measuring method is established by precision and feasibility analysis.The restriction of using this method to measure surfaces of roller gear cam is discussed, and the next research direction is confirmed. |
