Coefficient of efficiency of gear transmission determines the degree of energy perfection of motion conversion by the mechanism. Energy losses in gears arise as a result of friction between the teeth during their relative movement, friction in shaft supports, in seals, as well as when mixing oil in the gear case and squeezing it out of the depressions between the teeth.

In open thermodynamic systems, there is thermal and mechanical interaction of the working body with the environment and transfer of the working body through the control surface of the system.

Features of the gravity method of beneficiation of heavy unclassified minerals require intensive water currents at relatively high values of displacements, velocities and accelerations. This determines the application of a mechanical drive for the OMT type stripping machines. ...

By means of electronic modeling the influence of the size of the gap between the piston and the walls of the machine on the oscillatory motion of the liquid was studied, the maximum overpressures in the chambers of the machine were determined at different values of the gap, velocities and accelerations of the piston. ...

Modern methods of calculation of pneumatic hammers are based on the assumption that their working processes are equilibrium, and the mass exchange at filling and emptying of the working cavities of the cylinder occurs in accordance with the regularities of the steady flow of compressed air.

For electronic modeling of working cycles of pneumatic machines a relay switching device (RSD) is developed and used. It serves for changes in switching of the electronic model when solving problems described by different systems of differential equations at separate intervals of variables change.

A pneumatic percussion machine is a piston heat engine in which the potential energy of the working fluid (compressed air) is cyclically converted into the kinetic energy of the piston. The piston (striker) of this machine moves reciprocatingly under the action of compressed air pressure alternately supplied to the cylinder cavities by a special air distribution device. The kinetic energy of the piston is transferred to the working tool (drill, pick, chisel, etc.) upon their impact at the end of each cycle. Therefore, when studying the working processes of pneumatic percussion machines, one should choose a method that reflects both the nature of the thermodynamic processes occurring over time in the cylinder cavities and the nature of the piston motion. This leads to the necessity of jointly solving the system of differential equations of the energy balance of open thermodynamic systems in the cylinder cavities and the equation of motion of the piston.

A number of difficulties arise in the theoretical study of working processes of pneumatic impact machines. The complex character of thermodynamic processes occurring in the cylinder of a pneumatic machine necessitates the introduction of simplifying schematization. On the other hand, the approximate mathematical methods used to solve the system of differential equations of the working process of these machines introduce additional errors in the final result of the study. Moreover, it is impossible to separately assess these errors and prove or disprove the correctness of the adopted schematization of physical phenomena.