This monograph focuses on the dynamical researchwork on crank-piston mechanisms considering basic and additional motions. Inorder to have full dynamical analyses of piston machines and their mechanisms, thebook studies the crank-piston mechanisms with clearances in kinematic pairs. The tasks are carried out by focusing on friction, wear and impacts inmechanisms, as well as cracks formation in links and elasticity of details,with distributed and concentrated masses. Then, the reliability and durability ofthe mechanisms of piston machines is applied on oil and gas transportation. The monograph is meant for design specialists. It is also useful for specialists-manufacturers and designers of pistonmachines, scientists and lecturers, doctoral students.