261 / 308
261
Internal Combustion Engines
Friction Measurement – Tribology – Engine Mechanics
Reducing piston assembly friction is a central issue of
improving the efficiency of modern internal combustion
engines. Piston, piston rings, liner and lubricating oil
form a complex tribological system operating in a field of
constantly alternating velocities, pressures, and temper-
atures. Therefore a special research engine containing
a measurement device using the floating liner method
was developed at the institute. It allows the piston
assembly friction to be measured with a highly accurate
resolution up to 2 N under fired conditions. That enables
the detection of optimization potential by experimental
analysis. A second research engine was built up, con-
taining several sensors to measure crank-angle resolved
motions of the piston and the piston rings. Furthermore
the oil film thickness and oil transportation phenomena
are measured during fired engine operation. Recently,
even optical insight on the cylinder surface was prepared
by means of a glass window inside the liner (see above).
The measurement results of the three engines establish a
deeper understanding of the behavior and dependencies
in the tribological system.
Projects
■■
FVV project ‘Kolbenring-Öltransport II’
■■
FVV project ‘Kolbenring-Öltransport Glasliner’
■■
DFG project ‘Entwicklung eines kosten- u. verbrauchs-
günstigen Split-Verbrennungsmotors III’
■■
BFS Project ‘Truck 2030 – Bayerische Kooperation für
Transporteffizienz’
■■
Several projects funded by industry partners
Single cylinder engine equipped with glass window in the cylinder liner enabling in-situ measurement of the oil-film thickness on the fired engine.