Centering and friction reduction between parts of the cylinder-piston group

Abstract

The current study is devoted to the development of the relative motion model of the piston and cylinder liner. The piston and the cylinder liner may be parts of the internal combustion engine; plunger pump; piston compressor etc. The nominal radial clearance between the piston and the cylinder liner is very small, and is filled with viscous liquid or gas. The piston and cylinder performs a relative axial reciprocating motion in accordance with the predetermined law in time. Generally, the piston separates the "high" and "low" pressure areas. Therefore, the gap viscous liquid or gas are located between the eccentric moving walls in the presence of an axial pressure drop. The possible contact between the piston and the cylinder liner is a potential cause of the energy losses to friction and increased wear of the contacting parts. To reduce the damage from contact, it is desirable to achieve centering of the piston during its movement inside the cylinder liner. One way to achieve the centering of the piston is the profiling of it, which provides a supporting radial effect of the viscous liquid or gas.