Research On Parallel Indexing Cam Mechanism Driven By Single Disc Cam

A new kind of parallel indexing cam mechanism driven by single disc cam is invented to simplify the structure, reduce the volume and production cost, improve the performance of the existing mechanism. The research of kinematics and dynamics of the new mechanism is presented to provide a theoretical basis and technical support for the further design and development of this mechanism.After researching the equation of the existing parallel indexing cam profiles with the method of relative movement and the principle of isometric curves, the form and three essential characteristics of the cam of the new mechanism are proposed. On the basis of analyzing the three factors that influence maximum overall diameter of the cam of the new mechanism, the relationship among diameter of axle of the follower and roller diameter, wall thickness, overlap degree of the transmission process is concluded.Choose modified cosine functions as the motion principle of the follower, and establish the virtual prototype of the new mechanism, and then carry out the kinematics simulation analysis. By comparing the results of simulation and theoretical ones, the model is verified successfully.Based on the multi-rigid-body model mentioned above, the rigid-flexible coupled model is established in the ADAMS software, and then the dynamic simulation is carried out, whose results show that the design and modeling process of the new mechanism are both correct. At the same time the conclusion that the groove depth and the wall thickness of the cam affect the distribution uniformity of the contact force on the contact area is reached.After the dynamics simulation analysis, conclusions are drawn as follows:(1)the larger the curvature radius of the profile curve near the contact point is, the larger the stress of node on the curve is;(2)the stress of node that locate at the bottom of the outer wall of the cam groove is larger than those of other nodes at the remaining areas of the same theoretical contact line;(3)increasing the width of roller can significantly reduce the maximum stress of node.