An analysis of the influence of valve train on the power of high speed four stroke reciprocating engines

U ovom je radu analiziran utjecaj razvodnog mehanizma četverotaktnih motora sa unutarnjim izgaranjem na snagu tih motora. Prikazane su geometrijske i kinematičke značajke profila brijega bregastoga vratila kao i dinamika gibanja ventila, konstrukcije razvodnih mehanizama, te stupanj punjenja cilindara u visnosti o broju ventila po cilindru. Objašnjen je rad nekih od sustava promjenjivog razvoda ventila kao i elektromehaničkog razvoda ventila, te njhove prednosti i nedostaci. U šestom poglavlju je prikazan proračun bezudarnog brijega prema Kurzu za ravno vođeni čašasti podizač. Cijeli postupak je proveden u Matlab – i slijedi u prilogu kao i prikaz ventilskog sklopa motora sa jednim brgastim vratilom u glavi i i zravnim pogonom ventila putem ravnih čašastih podizača.In this article it's analysed an effect of four stroke internal combustion engines valve train mechanism on power of these engines. There are presented geometrical an kinematical characteristics of camshaft profile as well as dynamic of valve motion, valve train constructions and level of cylinder charging efficiency depending on valve number per cylinder. There are also explained operations of variable valve timing systems as well as electro-mechanical valve train mechanism and their advantages and disadvantages. In sixth chapter is presented calculation of non striking cam profile according to Kurz, for flat tappet. Whole procedure is performed in Matlab and follows in enclosure as well as illustration of valve train mechanism of the engine with one camshaft in cylinder head and with direct drive of valves by means of flat tappets