Issue of changes in technical states of a Diesel engiene as the result of wear of its tribological systems

The paper shows a necessity to consider the processes of load on and wear of tribological systems in Diesel engines (and therefore the changes in their states) in real conditions as random processes. This means that mathematical models for these processes can be random functions with an argument which is time (t) and with values which are random variables such as loads and wear of particular tribological systems. The load properties for the tribological systems have been presented as the main causes of their failures. It has been signaled that a stochastic dependence should be expected between mechanical load and thermal load, whose the intensity (force) can be defined by Czuprow’s convergence coefficient. A proposal has been submitted to accept that the tribological system load in Diesel engines is a stationary process with asymptotically independent increments. The reasons for this proposal have been presented in the form of relevant hypotheses and an exemplary graph of changes in pressure and temperature in an engine cylinder under operation. Also it has been signaled that the models of wear processes in tribological systems may be stochastic processes with special properties called semi-Markov processes. The wear properties for these systems have been explained in the form of relevant hypotheses.