TRIBOLOGICAL OPTIMISATION OF RECIPROCATING MACHINES ACCORDING TO IMPROVING PERFORMANCE

Abstract

Lowering fuel consumption and exhaust emissions continue to be prime targets in the development of technology applied for motor vehicles and their equipment. Into the focus of attention are the reduction of the vehicle weight as well as, in the field of internal combustion engine technology, more efficient combustion system and accessory components. As a complex system, the internal combustion engine accounts for a major part of the vehicle mass. The key components, the cylinder head and the cylinder block, for heavy loaded diesel engines, are today almost exclusively produced from aluminum. Also, by application of the aluminum pistons, it reduces engines weight and inertial forces, as well as the engine vibrations. According to the latter, the use of lightweight materials for construction of engine accessories as it is small air reciprocating compressor for braking system of trucks and buses, give contributions to the reduction of equipped vehicle mass. The advantage of aluminum with regard to the specific weight is notable, but exist the problem because it has considerable disadvantages in terms of the thermal expansion coefficient. The greater thermal expansion would cause unacceptable deformation during reciprocating machine operations. With additional coating on the cylinder liner surfaces it overcomes poor aluminum strain properties. By application of piston with tribological inserts towards lowering friction resulting in lower mechanical losses and higher performance. The authors hope to obtain more measurement data on the test bench for small air reciprocating compressors in the Engine Laboratory at the Faculty of Engineering, University of Kragujevac.