An Investigation on the Statical Strength of Solid Crankshafts (The 2nd Report)

Abstract

In this report, the authors have investigated in detail the effect of web dimensions and the crankpin fillets on the statical bending strength of single throw crankshafts by strain gauges.The conclusions deduced are as follows.(1) Stress concentration factors (k) are given by the following formulae as for web dimensions when other dimensions are the same : k∝1/ (b/d)0.3 (t/d) 1.2in load bending test, k∝1/ (b/d)0.3 (t/d) 0.8in web deflection test, where, bid and t/d are the ratios of web width and web thickness to crankpin diameter respectively.(2) The relation between stress concentration factor (k) and fillet radius (R) is expressed approximately by k∝ (1/R/d) 0.45in both load bending and web deflection tests.(3) The stress concentration factor (k) of the crankshaft having grooved fillet is nearly equal to that having ordinary circular fillet of the same radius.(Remark) In this report, k is denoted as follow : k=Bending stress at the fillet/Bending stress at the lower side of middle of crankpin