Abstract
This research employs the theory of inventive problem solving (TRIZ) in a systematic way to generate novel types of follower for the disk cam mechanism, and then analyzes and evaluates their relative merits and disadvantages of these novel followers. The first step for generating the novel followers is to analyze the quantitative features of the disk cam mechanism systematically. Then, with the aids of formulistic process, the problems can be defined specifically and converted into universal issues, which help to distinguish the features that need to be improved and the factors that may deteriorate. Finally, the solutions for resolving the universal contradictions are provided by applying the 40 TRIZ solution principles, and the innovative conceptual designs for solving the specific problems are developed. The design factors that are considered to be altered for the disk cam mechanism include the dimensions of cam-follower system, the pressure angle, and the contact stress. They are subsequently transformed into the features of universal problems such as velocity, force, tension, pressure, area, and size. After determining specific contradiction, the contradiction matrix and the 40 TRIZ solution principles are introduced to resolve the dilemma between those features. On the basis of maintaining the same required space with improved kinematic and dynamic characteristics, a variety of novel followers are created through the combination of the number, the size and the arrangement of the follower contactors. The generated conceptual configurations of the novel followers include the double roller follower, the concaved face follower, the symmetrical double roller follower, the symmetrical double oblique flat face follower, and the symmetrical double concave-faced follower. Furthermore, through the configuration modification for the novel V type follower with double oblique flat faces, an additional applicable follower is also investigated for potential practical application. Additionally, this research utilizes the concept of velocity instant center to derive the analytical expressions for the pressure angle and the cam profile, and also discusses the design limitations for each specific type of the follower configuration. Several examples are given to illustrate the advantages and disadvantages of those novel follower configurations. Among those conceptual designs, the translating symmetrical double roller follower, the symmetrical double oblique flat face follower, and the symmetrical double concave-faced follower will have two contact points with the cam profile during the dwell periods of the follower motion. Such a contact situation has the potential benefit for carrying a larger applied load. Therefore, this work also analyzes the contact forces exerted on the symmetrical double roller follower to illustrate its capability of carrying larger loads. In conclusion, employing the TRIZ theory and combining expertise experiences and knowledge, this work develops a systematic procedure to find out several novel types of cam follower, and further illustrates that some of them have practical potential.