STUDY OF KINETOSTATIC PARAMETERS OF SYMMETRICAL LINKAGE MECHANISMS WITH PERIODIC DWELL OF THE OUTPUT LINK

Abstract

The paper considers the problem of determining the kinetostatic characteristics of Chebyshev linkage mechanisms, whose link length ratios provide the plotting of symmetrical curves of the coupler’s point. The upper section of the coupler’s curve of the mentioned mechanisms was used to approximate a circular arc. Such mechanisms can be used independently in mechanical engineering, providing path generating motion of a link with the “best approximation conditions” according to Chebyshev within its certain segment. These conditions include the presence of a uniform deviation from a circular arc with the maximum possible number of interpolation nodes within the approximation segment of the coupler curve. Path generating linkage mechanisms can also be used as a basis for designing mechanisms with periodic dwell of the output link, which is considered in the article.

To determine the optimal geometric parameters for these mechanisms, it is essential to conduct both kinematic and kinetostatic analyses. In the presented paper, a methodology for determining the kinetostatic parameters of the dwell mechanisms is introduced, calculations according to the obtained formulae are also performed, and results are presented in the form of diagrams of maximum values of the main kinetostatic parameters of the mechanisms, such as: reactions in the kinematic pairs, instantaneous and cyclic efficiency coefficients, the force increasing coefficient, which allows to carry out the optimal synthesis of mechanisms with the dwell of the output link.

Based on the obtained dependencies, a computer program was made up, which was used to study the force loads on the mechanisms’ links under dynamic loading. The values of the dynamic parameters of linkage mechanisms that were obtained can be used for preliminary strength calculations of the links and parts of the mechanisms.