Determination of geometrical deviations of large crankshafts depending on the adopted conditions of their fixing and support

The paper presents the procedures developed to correctly assess the geometric condition of large crankshafts using a novel measurement system equipped with a specially designed prism support system with computer monitoring of support reaction forces. These procedures were developed for three variants of measurement execution corresponding to conditions: non-referenced (fixing of the shaft to be measured with the outer extremes of the faces in the spherical prisms and supporting the shaft in the central part with a set of supports referred to as ‘elastic’), referenced (fixing of the shaft to be measured by the outer extremes of the main journals in prisms and support of the crankshaft in the central part, as in the case of the previous variant, by a set of supports referred to as ‘elastic’) and realised in conditions similar to the traditional ones (fixing and support of the crankshaft by a set of prism supports maintaining a constant height position). Considering the utilitarian potential of the developed procedures, exemplary applications of their practical use in the measurement of large crankshafts are presented.