Theoretical Determination of Changes in Chain Networks Lengths

The article presents the results of theoretical studies conducted to determine the change in the length of the free strand of a chain drive with a variable center distance. In the research, the engagement of the chain with the driving and driven sprockets was considered as a 3-vector type, 5-link lever mechanism. During operation, in addition to natural wear in chain drives, elongation and changes in wrap angles due to vibration or oscillation are observed. This, in turn, leads to a decrease in traction capacity and uneven distribution of loads in the chain strands. Therefore, it is important to take into account the free strands of chain drives. The vector contour method is considered convenient for the analytical study of planar mechanisms. For this reason, this method is used in the geometric analysis of the equivalent 5-link lever mechanism. As a result of the conducted theoretical research, an analytical expression was obtained that allows determining the length of the chain strands, and based on its numerical solution, a graph showing the dependence of the chain strand length on the rocker rotation angle was constructed.