A foil thrust bearing (10, 14, 16, 18, 20) including a thrust bearing underspring disk (16) having a radially increasing spring force or load capacity. A plurality of spring sections (30, 32, 34, 36) formed in the underspring disk provide improved load capacity and pressure force distribution.

Thrust bearing underspring

An improved foil thrust bearing includes a pair of members arranged for relative rotation with respect to one another. One of the pair of members is adapted to rotatably support the other. A thrust bearing disk is operatively disposed between the pair of relatively rotatable members. The thrust bearing disk has a plurality of diverging surface ramps. The surface ramps can comprise an inner ramp and an outer ramp. The thrust bearing disk can also comprise a plurality of radial slots. A plurality of separately formed, converging surface compliant foils are disposed on the thrust bearing disk and between the ramps. An underspring element is operatively disposed between the thrust bearing disk and one of the rotatable members, with the underspring element having a plurality of alternating upper and lower ridges.

Foil thrust bearing

A compliant hydrodynamic fluid film bearing includes a flexible bearing sheet overlying and supported by a resilient support element having two corrugated spring foil support elements arranged in a staged, parallel spring array. The top spring element is more compliant in the bottom spring element and provides a compliant support for the bearing sheet at low rotor speeds to provide early development of load bearing capacity. With increasing rotor speed, the top support element deflects to the level of the second or lower support element which is stiffer and provides stronger support at higher speeds. At these higher speeds, the combined support element supports the bearing sheet at the correct profile to the moving bearing member and prevents collapse of the support element so that the bearing remains operative at high and ultra high speeds despite the increased load and stiffness of the hydrodynamic fluid film.

Multi-stage support element for compliant hydrodynamic bearings

An improved foil thrust bearing (10) includes a cooling fluid flow turbulence generating disk (18) placed between other foil thrust bearing elements, such as thrust bearing elements (16) and underspring elements (20). The inventive turbulence generating disk (18) generally provides improved transfer of heat through the foil and into the cooling fluid of foil thrust bearings (10) that may be used for high rotor speed applications. It accomplishes this by improving the transfer of heat through the foil and into the cooling fluid by generating turbulent cooling flow adjacent to the back of the top foil (16). The turbulent flow is generated primarily by a series of turns or protrusions introduced into the cooling flow stream. Alternate embodiments are disclosed that provide the turbulence generating elements as part of the underside of thrust bearing elements.

Foil thrust bearing cooling

A foil bearing turbomachine including magnetic relief of the thrust forces and static friction imposed on the foil thrust bearing during start up of the turbomachine.

Magnetic thrust force relief for a foil bearing turbomachine

A self-pressurizing hydrodynamic foil bearing having resilient foils providing support between a movable and stationary bearing member and further having resilient foil supports for supporting and stiffening the foils. The foil supports additionally generate Coulomb friction with another bearing member for enhancing the damping characteristics of the bearing.

Johan A Friedericy

Papers

Foil bearing arrangements