To overcome defects in the supply of pressurized lubricant, a hydrodynamic bearing for guiding a shaft (14) includes a stationary outer annular wall, a rotatable inner annular wall (20), and a space (22) between the walls. The outer annular wall comprises an opening for supplying pressurized lubricant to the space so as to form a film of load-bearing fluid. The bearing includes a cavity (30) externally defined by the inner annular wall (20) and axially defined by two transverse annular walls (31A, 31B) secured to the shaft (14) and arranged on both sides of the cavity. The inner annular wall (20) comprises fluid connection orifices (32) connecting the cavity (30) to the space (22). The cavity (30) is divided into compartments (50, 52) by a partition wall (48) configured such that the cavity forms a lubricant supply for a transient operational phase.

In order to effect a seal a porous material which comprises one side of two opposing surfaces is used to restrict and evenly distribute externally pressurized gas, liquid, steam, etc. between the two surfaces, exerting a force which is opposite the forces from pressure differences or springs trying to close the two faces together and so may create a non-contact seal that is more stable and reliable than hydrodynamic seals currently in use. A non-contact bearing is also disclosed having opposing surfaces with relative motion and one surface issuing higher than ambient pressure through a porous restriction, wherein the porous restriction is part of a monolithic porous body, or a porous layer, attached to lands containing a labyrinth, the porous restriction and lands configured to not distort more than 10% of a gap created from differential pressure between each side of the porous restriction.

A screw compressor utilizing radial and axial or thrust bearings to maintain the position of the rotors radially and axially and utilizing a damping fluid to dampen rotor vibrations. The damping fluid may conveniently be provided in the form of lubricant that is already used in the compressor to seal the clearances between the rotors and between the rotors and the cylinder during compression. The damping fluid is included in a squeeze film damper, arranged in a parallel arrangement with the radial or thrust bearings, which provides viscous damping to the rotor. The introduction of additional viscous damping such as may be provided by squeeze film dampers may result in significant reduction of compressor vibration regardless of the source of vibration.

A method includes controlling a bearing fluid supply system to provide the bearing fluid to a hydrostatic bearing of the turbopump assembly. The bearing fluid includes a supercritical working fluid. The method also includes receiving data corresponding to a pressure of the bearing fluid measured at or near a bearing fluid drain fluidly coupled to the hydrostatic bearing, determining a thermodynamic state of the bearing fluid at or near the bearing fluid drain based at least in part on the received data, and controlling a backpressure regulation valve to throttle the backpressure regulation valve between an opened position and a closed position to regulate a backpressure in a bearing fluid discharge line to maintain the bearing fluid in a supercritical state in the hydrostatic bearing and/or at or near the bearing fluid drain.

A compact bearing system is capable of variable load carrying capability and precision motion on a guideway. The compact bearing system includes a bearing body, a fluid medium, a sealing bearing member and a pressurizing action means. The bearing body includes an internal pocket with an open side facing a surface of said guideway. The fluid medium is contained inside said internal pocket and is contacted with said surface of said guideway on said open side. The sealing bearing member is contacted with said surface of said guideway and seals a clearance between said bearing body and said surface of said guideway to limit leakage of said fluid medium. The pressurizing actuation means pressurizes the confined fluid medium through a small passage by the principle of connected vessels, and the pressurized fluid medium carrying main portion of load carried on said compact bearing system.