The problem of determining of forces acting on piston groups and labyrinth seals is of great significance in calculating and designing reciprocating machines (piston compressors) taking while account the clearances in kinematic couples of the mechanisms. There are different processes in sealing the parts of these machines at the same time as the mechanical and thermodynamical processes. Investigation of complex problems concerning friction, oscillation, and impact phenomena in labyrinth seals of reciprocating machines allows for solving durability. Based on thermodynamic analyses, the method of determining the forces of gas pressure on the piston with the piston rod and the friction forces in labyrinth seals of piston compressors has been developed. Thermal analysis and an analysis of structural and damage due to the application of pressure and temperatures on the piston surface. The thermal analysis also was performed in ANSYS software.