Analysis and Synthesis of Cardioid Crank Guide Bar Mechanism with Approximate Dwell

The cardioid crank is a planetary mechanism, in which the locus of points on the planet gear is cardioid curve. By using the cardioid crank as the driving crank of the guide bar, the cardioid crank guide bar mechanism can be obtained, which is equivalent to the guide bar mechanism moving along the curve of the heart as the length and speed change, thus changing the motion characteristics of the guide bar. The approximate dwell motion mechanism of the cardioid crank guide bar is presented in this paper. The motion analysis of the mechanism is carried out, and the calculation methods of the dwell angle, the dwell fluctuating angle, the limit position of the guide bar and the swing angle of the guide bar are given. The influence of the center distance and the length of the planetary link on the motion performance of the mechanism are discussed. By means of function approximation method, the design formula of the mechanism according to dwell angle is proposed in this paper.