FINITE-ELEMENT ANALYSIS OF HERRINGBONE GROOVE JOURNAL BEARINGS - A PARAMETRIC STUDY

Currently, the herringbone groove journal bearing (HGJB) has important applications ill miniature rotating machines such as those found in t he computer information storage industry. Grooves scribed on either th e rotating or stationary member of the bearing pump the lubricating fl uid inward thus generating support stiffness and improving ifs dynamic stability when operating concentrically. The narrow groove theory (NG T), traditionally adopted to model the concentric operation of these b earings, is limited to bearings with a large number of grooves. A fini te element analysis if introduced for prediction of the static and rot ordynamic forced response in HGJBs with finite numbers of grooves. Res ults from this analysis are then compared to available experimental da ta as well as to estimates from the NGT. A bearing geometry parametric study is then conducted to determine optimum rotordynamic farce coeff icients. A discussion on the temporal variation of the bearing reactio n forces and force coefficients for a rotating journal with a small nu mber of grooves is also presented These changes can be significant at high operating eccentricities, possibly inducing a parametric excitati on in rotating systems employing this type of bearing.