Experimental measurement of big-end bearing journal orbits

This paper describes a novel experimental approach to the measurement of bi g-end bearing journal motion in reciprocating machinery. The procedure is b ased upon measurements recorded from inductive displacement transducers mou nted in the crankshaft, which measure the instantaneous clearance between c rankshaft journal and the big-end bearing surface of the connecting rod. Th e results of the work demonstrate that the procedure is a feasible way of c ollecting 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.