Effect of the Collar Displacement on the Fixed Pads Thrust Bearing Characteristics

Abstract

The paper presents results of numerical studies of the effect of the centrifugal or screw compressor rotor thrust collar displacement within the clearance on the integral and dynamic characteristics of a fixed pads thrust bearing. The direct dynamic problem is set using the Sm2px3Txτ software program enabling an analysis of the bearing capacity, damping, vacuum formation in the lubricating film, occurrence of the negative bearing capacity, temperature operation mode and alteration in the power loss. The Sm2px3Txτ software program is based on numerical implementation of the periodic thermoelastohydrodynamic mathematical model describing thermal, hydrodynamic and deformation processes in the lubricating film and boundary layers of a thrust bearing. The paper marks significant effect of the rotor collar displacement speed relative to the plane of the pads under the action of an external disturbing axial force of the compressor determined by the cyclic frequency of the collar displacement under the harmonic surge law on the considered characteristics. A negative carrying capacity could appear regardless of the thrust bearing geometric dimensions at the cyclic frequency increased value, which corresponds to the high-frequency compressor surge. The most dangerous zone of the working surface of the fixed pad near the trailing edge during cyclic alteration in the hydrodynamic pressure is determined. Combination of the high-temperature operation and the cyclic process hydrodynamics could lead to a failure in the fluid film thrust bearing. The developed Sm2px3Txτ software program makes it possible to simulate the described cyclic processes

Please cite this article in English as:

Sokolov N.V. Effect of the collar displacement on the fixed pads thrust bearing characteristics. Herald of the Bauman Moscow State Technical University, Series Mechanical Engineering, 2025, no. 1 (152), pp. 108--130 (in Russ.). EDN: TXSKFW

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