THE RESEARCHES ON THE TRIBOLOGICAL PROPERTIES OF ELEMENTS OF THE SEAT INSERT-VALVE-VALVE GUIDE ASSEMBLY

The researches have been carried out, where the object has been the elements of valve trains in the different combustion engines. Those elements have been valve, valve guide and seat insert. The analysed valves have been driven by special camshaft, with the cams of trapezoid shape. The special research stand has been elaborated and its scheme has been presented in the article. The mentioned research stand has been driven by electric motor. The rotational velocity of the camshaft has been controlled and measured. The aim of the researches has been to obtain values of wear for valve, seat insert, valve guide vs. valve lift, and rpm of camshaft. The dynamic parameters have been analyzed for the seat insert – valve – valve guide assembly, experimentally and by simulation either. During researches the values of valve lift, of valve acceleration, of temperature for seat insert and additionally sound level have been measured. The wear of valve, seat insert and valve guide has been measured, basing on their initial and post-research geometry. The results of experimental researches obtained for different materials for valve, valve guide and seat insert have been presented in the article. The simulation model of the analyzed seat insert – valve – valve guide assembly has been elaborated and presented in the article. Such model has been needed to calculate the values of the settle velocity for the analyzed valve. The wear of titanium valve has been a little greater than of the steel valve, the wear of cast iron seat insert mating with steel valve has been much greater than for titanium valve case. The wear of valve guides, made of bronze has been several times less than those of cast iron.