Modeling and PreSizing Process for Hydrostatic Thrust Bearing with Special Consideration to Performance Robustness Within a Wide Temperature Range
Résumé
The research presented in this communication proposes a preliminary sizing approach of hydrostatic thrust bearings used in an embedded power system, which faces severe environmental and power consumption constraints. In particular, the hydrostatic thrust bearing shall be compliant with its specification within a wide temperature range and shall minimize the consumed flow. The performance of the thrust bearing is assessed in terms of static bearing force, consumed flow rate and stiffness. A particular attention is paid to the influence of the type of fixed hydraulic restriction. The short tube orifice is considered as an attractive solution that combines the advantages of both capillary tube and orifice types. In this attempt, a lumped parameter model of the short tube is proposed. The structure of the model is defined on basis an analytical approach while the model’s parameters are identified from computational fluid dynamics simulation. This new model enables the recess pressure to be calculated in order to compute the performances of the thrust bearing versus fluid temperature. Dimensionless results are used to facilitate the comparison of the sensitivity to temperature of the designs based on the above-mentioned types of hydraulic restrictions. The behavior – function of the temperature – of a given hydrostatic thrust bearing geometry is superimposed for the three hydraulic resistance models in order to emphasize the high contribution of the proposed short tube orifice model and sizing process to the global optimization.