Abstract
The effects of mean radial clearance and bearing length on the stability threshold speed are investigated. The dynamic Reynolds equation is applied to the system, and numerically solved with the pressure drop mainly due to the axial acceleration of the oil at the inlet end of journal bearing being taken into account. The stability threshold speed is obtained by linearizing the equation of motion about the equilibrium and applying the Bairstow-Hitchcock method to solve the characteristic equation. The stability threshold speed increases with pressure difference except for the range of low pressure difference regardless the dimensions of mean radial clearance and bearing length. Under the same pressure difference, mean radial clearance and bearing length influence the stability threshold speed, which increases with the dimension of mean radial clearance in case of relatively large bearing length and with decreasing of the dimension of bearing length in case of relatively small mean radial clearance.
