  An explanation of the mechanism of irreversible dynamics was offered. The
explanation was obtained within the framework of laws of classical mechanics by
the expansion of Hamilton formalism. Such expansion consisted in adaptation of
it to describe of the non-potential interaction of a systems. The procedure of
splitting of a system into equilibrium subsystems, presentation of subsystem's
energy as the sum of energy of their relative motion and their internal energy
was the basis of the approach which was used for the analysis of nonequilibrium
systems. As a results the generalized Liouville equation and equation of
subsystems interaction was obtained. Based on these equations, the irreversible
transformation of energy of the relative motion of subsystems into their
internal energy was proved. The formula which expresses the entropy via the
work of subsystems' interaction forces was submitted. The link between
classical mechanics and thermodynamics was discussed.
