A journal bearing includes: a carrier ring; a plurality of bearing pads disposed on a radially inner side of a lower half region of the carrier ring, and configured to support a rotor shaft from below; and a guide metal disposed in an upper half region of the carrier ring, in center with respect to an axial direction of the rotor shaft, so as to cover an upper region of an outer peripheral surface of the rotor shaft.

A control apparatus includes a constant storage portion that stores constant values of an electromagnet coil including a resistance value Rm, an inductance Lm, a sampling time Ts, etc. A current storage portion stores previous current command values Ir having been regularly sampled by a microcomputer inside a current control circuit. A low-frequency feedback circuit generates a signal for suppressing an error between DC components and low-frequency components of an input current command value Ir and a detected current value IL and outputs the signal. An output voltage computing circuit calculates, based on the input current command value Ir[n+1], a stored value Ir[n] of the current storage portion, a stored value of a constant storage portion, and the signal of the low-frequency feedback circuit, a voltage for suppling the electromagnet coil with a current in accordance with a command, and outputs the calculated voltage.

Apparatus and methods for controlling a pressure differential across one or more seals of a bearing chamber in a gas turbine engine are disclosed. In some embodiments, the apparatus comprises a scavenge pump in fluid communication with an interior of the bearing chamber for driving oil from the bearing chamber; and a venting valve. The venting valve is configured to cause venting of the interior of the bearing chamber in parallel to the scavenge pump based on the pressure differential across the one or more seals.

A membrane restrictor adapted to be connected to a pump and a bearing is provided. The pump is adapted to supply fluid to a location between the bearing and the rail through the membrane. The bearing is adapted to be disposed on a rail. The membrane restrictor includes a casing and a membrane. The casing has a chamber, an inlet and an outlet communicating with each other through the chamber, and a restricting plane. The pump is adapted to be connected to the inlet; the bearing is adapted to be connected to the outlet. The membrane is disposed in the chamber. The restricting plane is an inner surface of the casing adjacent to the outlet and towards the membrane. Dimensionless stiffness of the membrane is Kr*, and 1.33K.sub.r*2. K.sub.r*=K.sub.rL.sub.0/(p.sub.sA.sub.r). Here, K.sub.r is stiffness of the membrane, L.sub.0 is a distance from the membrane to the restricting plane when no fluid is supplied by the pump (i.e., assembling clearance of the membrane), p.sub.s is pressure supplied by the pump, and A.sub.r is an effective area of the restricting plane. A hydrostatic bearing module having the membrane restrictor is further provided.

A centrifugal compressor includes a rotation shaft, an impeller, a housing including a first chamber, a second chamber of which pressure is lower than the first chamber, and a partition wall that partitions the first chamber and the second chamber and includes a through hole through which the rotation shaft is inserted, and a seal member arranged in the housing. The seal member includes a gas seal and a support. When the rotation shaft is rotating, the gas seal surrounds an outer circumferential surface of the rotation shaft in a non-contact state in which dynamic pressure forms a gap between the gas seal and the outer circumferential surface of the rotation shaft. The support supports the gas seal in a state in which the gas seal is movable in a direction intersecting an axial direction of the rotation shaft.

A vacuum double structure includes: a tubular and metal inner wall member; a tubular and metal outer wall member in which the inner wall member is accommodated; and a sealing member provided between a facing surface of the inner wall member and a facing surface of the outer wall member. The sealing member includes an annular spacer, a first annular packing material, and a second annular packing material. The annular spacer is provided between the facing surface of the inner wall member and the facing surface of the outer wall member.

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 dustproof seal structure includes a rotor assembly and a stator assembly rotatably supporting the rotor assembly. The stator assembly forms a horizontal thrust aerostatic bearing between a lower surface of the thrust plate and an upper surface of the stator assembly when compressed air is supplied between the lower surface of the thrust plate and the upper surface of the stator assembly. The thrust plate and the stator assembly form a sealing portion through which the compressed air flows. The sealing portion includes an inclined flow path whose height increases from an outer peripheral surface of the thrust plate toward the inside in a radial direction.