Analysis of water-lubricated journal bearings with multiple axial grooves.pdf

Technical Note 135 Analysis of water-lubricated journal bearings with multiple axial grooves B C Majumdar1*, R Pai2 and D J Hargreaves3 1Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur, India 2 Department of Mechanical Engineering, Manipal Institute of Technology, Manipal, India 3Department of Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland, Australia Abstract: The steady state and dynamic characteristics including whirl instability of water- lubricated journal bearings having three axial grooves are obtained theoretically. The Reynolds equation is solved numerically by the ®nite difference method satisfying the appropriate boundary conditions. The dynamic behaviour in terms of stiffness and damping coef®cients of ®lm and stability are found using a ®rst-order perturbation method. It has been shown that both load capacity and stability improve when smaller groove angles are used. Keywords: axial groove, journal bearings, steady state, stability, water-lubricated NOTATION t time (s) W steady state load (N) W , W components of load along the line of centres C radial clearance (m) r t D diameter of the bearing (m) and perpendicular to the line of centres (N) Drr , Dff , Drf , Dfr