Performance Criteria for High-Speed Crank-and-Rocker Linkages—Part I: Plane Crank-and-Rocker Linkages

Abstract

Criteria are given for evaluating the performance and determining the dimensions of plane crank-and-rocker mechanisms suitable for operation at high speeds. In contrast to the classical procedure of simulating the acceleration pattern of the slider-crank mechanism by means of centric crank-and-rocker linkages, a family of crank-and-rocker linkages has been found, with a more nearly sinusoidal acceleration pattern, i.e., one which tends more nearly to simulate the acceleration variation of a scotch yoke. At the same time the transmission-angle variation and the ratio of minimum to maximum link lengths is controlled. A pocket-calculator procedure is described and illustrated by means of a numerical example.