Dynamic characteristics and stability of high speed cylindrical journal bearing

The operation of plain circular journal bearing at high speed is restricted by the excessive temperature that is generated in the oil film and by the loss of stability. Low costs of machining, high-transmitted loads are the advantages of these types of bearings. Better knowledge of bearing operation and its stability from the point of hydrodynamic theory of lubrication and theory of vibration can be affected by modifications of bearing design. These modifications should result in the higher speeds of operation, decrease in power losses and better bearing stability. The basis of stability determination is the dynamic characteristics of bearing. For the plain circular journal bearing the dynamic characteristics has been calculated. Stability of high speed, symmetric rotor was determined, too. Different values of bearing length to diameter ratio, and relative clearance were assumed. Reynolds', energy and viscosity equations were solved by means of iterative procedure. Adiabatic oil film, laminar flow in the bearing gap as well as aligned orientation of journal in the bearing was considered.