Abstract: Transformed the six-bar guide-bar mechanism realizing linear displacement in automatic instruments in to a basic rotating guide-bar mechanism, established the mathematical model of velocity approaching constant by the classical approximate synthesis theory and the modern error theory, discussed the influences of the existent region of main mechanismic parameters on kinematic and dynamic properties, analysed the theoretical transmission ratio error, advances systematic, complete steps and methods for dimensional synthesis of this mechanism with computer aided design. All information about initial values for design is provided by the chart, thus the synthesis can be carried out by minicomputer, the process shows that it is easy to converge, and the optimum equal approximation guarantees the error of derived mechanism in the approximation region is minimal.

Key words: Computer aided design, Linear displacement, Rotating guide-bar mechanism, Transmission ratio Error, cloud model, output power, performance analysis, sensitivity, volatility, wind turbine