Journal Bearing Performance for Combinations of Steady,Fundamental and Harmonic Components of Load

Abstract

The performance of a complete journal bearing is obtained for a vertical cyclic load of the form

It has already been established that the ratio of the rate of load application to that of journal rotation (ω₁/ω) is a prime factor in the bearing behaviour, and for the case where P_n = 0, values of this ratio slightly less than 0·5 were found to give rise to critical changes in the bearing performance depending on the ratio P₁/P₀.

Present test results show that the superposition of the harmonic load component P_n would, in general, bring some changes to the performance characteristics at the ω₁/ω value corresponding to this harmonic, that is, at nω₁/ω ⋍ 0·5, and some simultaneous related changes (in the opposite sense) at the ω₁/ω value corresponding to the fundamental component P₁, that is, at ω₁/ω ⋍ 0·5, the extent of these changes being a function of the amplitude ratio P_n/P₁.

The phenomenon is explained in the light of the theory of vibrations, and the analysis is extended to include the case of a variable load on a uniformly rotating journal.