Simulation diagnostics of power train mechanical drives

Abstract

Mechanical drives have become the most widely used in design of agricultural machinery. In comparison to drives of machinery applied in other sectors of national economy, they are distinguished by their design features, performance, and cost-performance ratio. In this regard, diagnostics of mechanically driven parts of agricultural machinery is a key to the overall harvester diagnostics. In practice, health of drives is tested with subjective assessment methods, as a rule. The authors suggest application of a kinematic method for diagnostics of agricultural machinery drive trains during their operation; this method implies analysis of position changes and movement of mating parts: wear of parts and backlash of mating drive parts may be assessed by establishment of geometric parameters of diagnostics (linear and angular movements). The total transmission backlash may be established by dynamic torque appearing in transient states of mechanism operation; such total backlash characterizes dynamic errors in movement of an outlet member, which is a result of dependence of equivalent moment of inertia and drag torque from the velocity transmission error. Such diagnostics of potato harvester transmission allows checking of backlashes in separate sections of the chain, as well as assessment of quality of its components adjustment and maintenance. The research data were used for evaluation of overall engineering state of the harvester and determination of dynamic parameters of its components drives.

Connection of diagnostic parameters with the technical condition of the engine

“…For a serviceable engine, the maximum moments of resistance to scrolling through the cylinders are approximately the same and equal to Msc = 42 ... 44 Нm. Such a character of the change in the moment of resistance to scrolling confirms the hypothesis that it can be accepted as a diagnostic parameter for assessing the technical condition of individual cylinders [4].…”