SLIDING COUPLES FOR VALVE GUIDES AND VALVES OF PICTON COMBUSTION ENGINES

摘要

The article deals with the basic mechanisms of wear of the intake and exhaust guides of the valves and the valves themselves, which occurs during the operation of internal combustion engines. Particularly unfavorable conditions for friction pairs occur when operating engines with alternative fuels, such as natural gas, biogas or landfill gas, which may contain high amounts of sulfur. The article further describes modern materials and surface treatments of valves and valve guides. Furthermore, the article deals with non-destructive analysis of mechanical properties of guides, specifically the modulus of elasticity and strength. These properties are calculated by mathematical relationships that use the real and ultrasonic thickness of the material and, based on the change in thickness, express the mechanical properties.