Remarchuk M. Energy-efficient powertrains for road construction machines

The thesis is concerned with solving the problem of raising the power and decreasing inefficient fuel losses during the working cycle of a road construction equipment (RCE) on the basis of improving powertrains and specifically their hydraulic systems at the expense of cyclic efficiency factor of operator-machine-operating environment system (OMOE system). As a result of the investigations, mathematical models have been elaborated for determining: general efficiency factor for all RCE hydraulic systems at all stages of their lifecycle; a rational diameter of RCE hydraulic system mains when they are designed as the object of the system. A combined experimental-and-theoretic method for measuring general performance, and for determining both RCE hydraulic system running hours under loading and residual running hours. Simulation models have been obtained to determine running hours and marginal values of performance, due to which the range of effective utilization of RCM hydraulic systems under service conditions is identified. The mathematic models describing liquid lubricating in movable joints of hydraulic cylinders and control valves have been specified. A hypothesis on similar nature of powers one of which is spent on starting the hydraulic cylinder piston, and the other one provides its continuous motion has been proposed and proved. The control system for valve distributors and hydraulic cylinders that are parts of the motor group in various road construction equipment has been improved