Patent ID: 7367713
Filing Date: 2008-05-06
Classification: F16C

Abstract:
1. A journal bearing arrangement for a rotatable shaft comprising: (i) a housing configured to surround a shaft space and having a housing surface facing into the shaft space, (ii) a plurality of arcuate bearing pads arrayed about the shaft space overlying the housing surface, each having a bearing face adjacent the shaft space and a body face adjacent the housing surface, and (iii) a mounting arrangement, arranged to support at least one bearing pad with respect to the housing surface movable relative thereto in a direction to and from the housing surface, including associated with each said movable pad, a stop comprising a restraining boss and a shoulder provided one each by the housing and bearing pad, said boss having a head portion arranged to overlie the shoulder to limit the extent of pad movement away from the housing surface and permit displacement of the bearing pad towards the housing surface, and a spring arrangement, operable to bias the pad away from the housing surface to the limit imposed by the stop and exert on said pad stopped by the stop a predetermined level of pre-load and, in response to load applied to the bearing surface exceeding said pre-load level, permit displacement of the pad towards the housing surface, the spring arrangement further comprising a plurality of individually deflectable resilient elements, with the individually deflectable resilient elements comprising leaf springs extending circumferentially with respect to the housing and shaft space, and the spring arrangement comprises, associated with each bearing pad between the pad and the housing surface a stack of said leaf springs arranged to bear one on another in a radial direction, said stack of leaf springs comprises associated with each bearing pad at least a first spring terminating adjacent one end region of the pad and pivotally secured thereto, a second spring terminating adjacent the opposite end region of the pad and pivotally secured thereto, and a third spring mounted at its centre on a spigot extending along a radial axis and constrained by the spigot to sliding motion along the spigot and in respect of displacement from the housing surface.