Cooled pads with bioinspired gyroid lattice for tilting pad journal bearings: Experimental validation of numerical model for heat transfer

Hydrodynamic journal bearings are essential components for industrial rotating machineries. Continuously growing specific power allows more compact and efficient machines to be obtained, by reducing the environmental footprint of production plants. The aim of this work is to provide a new design of an innovative pad for Tilting Pad Journal Bearings (TPJBs) with an embedded cooling circuit, able to limit the oil film temperature. As a result, specific load can be increased leading to a possible downsizing of the bearing and reduction of lubricant quantity. The heat exchange in the cooling circuit of the pad has been enhanced using bioinspired gyroid lattice. The thermo-mechanical study of the pad has been performed with both numerical and experimental analysis. The resulting thermal and mechanical performances have been calculated and discussed. The tested components have been manufactured in stainless steel by using a metal 3D printing technology, based on polymer-metal feedstock extrusion. A performance analysis is conducted to catch differences between the nominal and the printed geometry. The prototype is able to dissipate the generated heat with a higher efficiency, and the pressure drop inside the cooling circuit can be estimated with the numerical model here proposed.