A Research On The Pure Rolling Contact Translating Follower Disk Cam Mechanism

The cam mechanism have been widely used in mechanical equipments due to the simple structure, and easy to achieve complicated follower motions. But the relative motion contact between cam and follower always form huge power loss in mechanisms, so this kind of mechanism always couse many restrictions in high efficiency driven systems. How to achieve the contact between the cam and translating follower to be pure rolling contact, is the most effective method to solve the relative slip problem and increase efficiency rapidly in cam mechanisms.The relative slip motion between two links can be achieved by the pure rolling contact motion of a pair of centrodes that have been permanent connecttef on the two links. According to this principle, this paper has derived a set of design formula for the cam mechanism profile curve. To design a cam mechanism in this way, could make the pure rolling contact in the translating follower disk cam mechanism come true, and achieve the specified complicated follower motion at the same time. This paper also has analysed the features of the relevant parameters, such as the pressure angle,critical pressure angle,allowable pressure angle,mechanical efficiency and base radius.According to the analyses results about the pure rolling contact cam mechanism, this paper has offered a set of design proposal about the cam mechanism completely. Design a cam mechanism in this way, not only could achieve the specified complicated follower motions, but also could keep pure rolling contect during the return stage,rise stage and rest stage continuous. This paper has found another way by zoom the profile curves to design the cam mechanisms, which have the same follower motions but their strokes are different. Design in this way, the manufacturing technology of the cam mechanisms which could achieve different strokes has been simplify.At last, this paper has made a practical design case about a pure rolling contact cam mechanism as an example, obtained a set of intact design formula about the profile curves of the cam mechanism, and built 3D models of this case in 3D software "Solidworks". After that, the paper has did kinematics analysis in kinematics analysis software "COSMOSMotion", measured the motion features on the cam mechanism models, compared with the design requirements and found out that the results are basically the same. The paper has recorded the simulation video and found some special points on the profile curves of the cam and translating follower. Through the video, the paper has checked the feature of the pure rolling cam mechanism, each contact point was on the centrode.