Tilt pad hydrodynamic bearing for rotating machinery

Abstract

A tilting pad bearing for a rotatable surface includes a plurality of circumferentially-arranged tilting pads, each of the tilting pads having a working surface and a trailing surface. A lubrication device for lubricating fluid is detachably affixed to the tilt pad leading surface or is formed integral with the tilting pad. The lubrication device has a fluid conduit and a cavity that provide the cool lubricating fluid to those portions of the rotating collar which need the most cooling. The conduit has a ninety degree turn so that the cooling fluid has a velocity vector normal to the boundary layer of the hot carryover fluid. The outlet of the conduit is positioned, and the cavity is designed, to provide the greatest amount of cooling fluid where the rotating surface is the hottest. The lubrication device also has a wiper to wipe hot carryover fluid off of the rotating surface. The amount of lubricating fluid and bearing power losses are substantially reduced. In the thrust embodiment, the bearing has a smaller axial height because loads imposed by the rotating surface are borne by the bearing elements, not by the bearing retainer. A hydraulically actuated feed piston closes the gap between the pad and retainer to convey lubricating fluid to the pad working surface. Equalizing link contact stresses are reduced by using conformal cylindrical surfaces and line versus point contact.