Bending Deflection of a Crankcase of High Speed Internal Combustion Engines

Abstract

Bending rigidity of a crankcase of high speed internal combustion engines is usually smaller in the horizontal-transverse direction of the engine, because of its common hanger-bearing-type construction. For this reason, the elastic vibration appears mainly in the horizontal direction. In our research the bending deflection of a crankcase was measured under such conditions that the load was applied to the middle point of a crankcase in the horizontal-transverse direction being simply supported at the both end-bearing centres. In analysing the results of bending tests with several models of crankcase, the calculating equations for the bending deflection of a crankcase were induced from "Torsion Theory of Thin Sections"with some modifications. The results of bending tests on regular engines show that those equations are practically adequate to calculate the deflection of a crankcase.