Experimental measurement of big-end bearing journal orbits

Abstract This paper describes a novel experimental approach to the measurement of big-end bearing journal motion in reciprocating machinery. The procedure is based upon measurements recorded from inductive displacement transducers mounted in the crankshaft, which measure the instantaneous clearance between crankshaft journal and the big-end bearing surface of the connecting rod. The results of the work demonstrate that the procedure is a feasible way of collecting experimental data for comparison with the output from theoretical models. Experimental data are presented for a single-cylinder four-stroke compression ignition engine operating under various load conditions.