Advances of Bearing Design for Remote Hydro Power Locations

Abstract

Thia paper describes the design and experimental investigation of a new, high speed thrust and journal bearing for hydro power applications. The experimental work covered tests in which the bearing was operated in a self-contained mode using water cooling as well as in a conventional external circulating oil arrangement. A range of test conditions were applied substantially in advance of those available previously for a bearing of this sort and in particular very high machinery overspeeds were simulated sucessfully. This work opens up the possibility of providing substantial hydro installations free from external lubrication systems. The attendant cost reduction and maintenance implications of this are considerable and relevant especially in those more distant locations where human and mechanical services are not readily available.

Introduction

There have been numerous experimental studies published over many years concerning the behaviour of hydrodynamic bearings. In the main these reports have considered radial loading (journal bearings) or axial loading (thrust bearings). In practice, however, the majority of bearing designs are configured to accept a combination of radial and axial loads. It is perhaps unfortunate therefore that this class of combined bearings should be poorly represented in the literature.

This paper covers part of a recent extensive experillental progrnae to investigate the performance of a new, large, high speed thrust and journal bearing which incorporates some innovative features and is designed for a range of demanding industrial applications such as hydro-generators and water turbines. Because of the very considerable horizontal and vertical loads involved and the need to apply these independently a completely new test rig was devised which is described in the paper.