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Chain transmissions are widespread in drives of machines used for various industrial purposes. In order to study drive dynamics, it is important to know the dissipative characteristics of its components and gears. However, the information on the damping ability of chain transmissions in research and technical literature is limited and fragmented, which makes the topic of this work, dedicated to the study of energy dissipation in transverse vibrations of chain transmission branches, of great current interest. The objective of this work was to study and determine the quantitative characteristics of energy dissipation in a drive chain experiencing the most common form of transverse vibrations as a string with fixed ends, which is characteristic of transmissions with large masses of sprockets and parts attached to them. To achieve this objective, a mathematical model of the dissipation of vibrational energy was developed using a method of estimating energy losses due to friction when parts of the chain’s hinge joint slip in a compressed contact. Engineering formulas for calculating energy dissipation per cycle of vibrations and absorption coefficient were obtained. The adequacy of the developed model and the obtained calculation formulas was confirmed by the results of the experimental determination of the absorption coefficients of the chain using the method of free damped vibrations. The results of the study allow us to conclude that chain transmissions have an increased damping capacity, and to determine the influence of transmission parameters and the oscillatory process on it.

Chain transmissions are widely used in drives of hoisting-and-transport and ag-ricultural machines, as well as in a number of machine tools and technological equipment in various branches of industry. However, a significant disadvantage of these transmissions is the high vibration activity under high dynamic loading. In this regard, the study of dynamic loads that occur during chain vibrations and affect the operability of the machine drive is one of the essential tasks of its dynamics. The article presents experimental studies performed in order to determine the maximum dynamic loads in a chain transmission of a machine drive with transverse vibrations of the chain. The most common case of transverse vibrations of a chain loop is studied as a string with fixed ends. This type of vibration is typical of chain transmissions with large masses of sprockets and parts attached to them. The article presents a description of an original test bench with an automated system for collecting and processing experimental data and a test procedure. The obtained experimental data are presented in the form of tables and graphical dependences of the maximum dynamic loads on the tension force of the chain average per cycle of vibrations and the amplitude of its transverse vibrations in the center of the span, related to its length. As a result of approximation of the experimental data array, an empirical formula is proposed that can be used in dynamic calculations of the drive. It is established that the maximum dynamic load and its amplitude increases with the increase of the ratio of the amplitude of transverse vibrations of the chain in the middle of its span to its length and the initial tension force of the chain. The ratio of the dynamic load amplitude to the tension force of the chain decreases with the increase of the latter.

For the formation of a high-quality package of cross winding on machines equipped with winding mechanisms with a frictional drive of the package, it is necessary to include special devices in their composition that provide a change in the speed of the yarn feeder or bobbin according to a periodic law with a cycle duration of at least six periods of the yarn feeder movement. Changing the speed of the bobbin can be provided by slipping it by a controlled amount. The amount of slip is determined by the appropriate selection of the winding shaft acceleration (deceleration) and the pressing force of the bobbin against the winding shaft. A mathematical model has been obtained that describes the change in the difference between the displacements of points on the surface of the bobbin and the winding shaft when the winding shaft is accelerated. It is shown that in this way it is possible to effectively eliminate defects in the winding structure in the form of bundles and ribbons.