Abstract This is a combined design of type Ⅱ of parallel mechanism, which is used to realize arbitrary trajectories by the combination of cams mechanism. The combined cams mechanism and the method of using analysis to design it, and establishes cam’s mathematical expression through analysis method. Then can show the opposite moving relation between input component and output component, in order to design moving tracks and cam’s outline. Also designs system’s total flow chart. Illustrates arbitrary moving tracks’ combined organization’s program design and method, the result of program’s execution and so on through combine program and interface method. uses animated imitation to test and verify the design’s result. The whole program’s process holds mechanical innovation as its foundation, it take the VB as a developing platform. Adopting module design to realize arbitrary trajectories, the design’s result achieves the desired results. 49543
Keywords: Simulation technology，Parallel combination， Arbitrary trajectories，Cam mechanism，Mechanism Design
Introduction
With the development of the mechanization and automation of the production processing. It is the higher demand of the characteristics of movement of bodies and power for output of the mechanism, but the single basic mechanism has some limitations, it can not meet certain performance requirements, more and more demanding requirements of movement trajectory of mechanism in the project, such as the control mechanism, compound feed mechanism etc. Because of the reasons of design, processing and installation etc. On many occasions, the equipment can not be fully realized designer’s intent, People have to adopt the approximate the trajectory. The demand for high precision, complex movement is getting more and more, with the continuously progress of machining capacity. Especially in the processing of some small and sophisticated components, this job will require very precise trajectory of the cutting tools. So there are the urgent requirements of the realization movement trajectory for the mechanism design. Therefore, it is urgent task of enhancement the mechanical innovation and accelerates the pace of innovation machinery to meet the needs of our daily processing for the machinery industry.
The basic mechanism generally includes connecting rod, cam, gear, intermittent, etc. Although these basic mechanisms are very broad for the application, but they all have also some limitations, for example. Linkage mechanism must be to solve the balancing problem for the high-speed running, some special law of motion with a single linkage is also difficult to achieve. The cam mechanism can receive the arbitrary law of motion, but the trip is not adjustable. The gear mechanism has good characteristics of movement and dynamic, but the mode of motion is simple. Ratchet mechanism, geneva Mechanism and other intermittent are not ideal characteristics of kinematic and dynamic, with the inevitable shock, vibration, and fluctuations in velocity and acceleration, etc. To solve these problems, the need for innovative design， full use of the good performance of the basic institutions, improve their bad characteristics.
The mechanism innovative is many ways, composition, evolution and variation, tectonic movement chain, and regeneration, etc. Which the combination theory can usually meet the requirements of trajectory, but also has good movement and dynamic characteristics, and make up for the shortcomings of a single mechanism. The mechanism characteristic can be more perfect, more perse forms of movement after combination.
Combination mechanism
Combination mechanism can be pided into series connection, parallel, composite and stacking combination, etc. which parallel combination mechanism can constitute a new type with two or more parallel arrangement, composite combination mechanism can also constitute a new type with a two degrees of freedom and an additional by the method of parallel arrangement. Usually it can utilize the commonly method to realize motion trajectories, with combination of different types. 并联组合凸轮机构设计英文文献和中文翻译:http://www.751com.cn/fanyi/lunwen_52550.html