A bearing structure includes a plurality of wave-shaped grooves and an inner surface. The wave-shaped grooves are formed on the inner surface for receiving a lubricating fluid. Each of the wave-shaped grooves extends along a longitudinal axis of the bearing structure. Each of the wave-shaped grooves includes a first peak section, a second peak section, two first connecting sections, two second connecting sections and a trough section. The two first connecting sections are connected to opposite sides of the first peak section, and the two second connecting sections are connected to opposite sides of the second peak section. The trough section is disposed between the first peak section and the second peak section, and the trough section is connected to one of the first connecting sections and one of the second connecting sections. The first and second peak sections and the trough section have a circular arc structure.

A circumferential seal assembly capable of separating a gas into two separate flow paths before communication between a rotatable runner and a pair of seal rings is presented. The seal assembly includes an annular seal housing, a pair of annular seal rings, a rotatable runner, and a plurality of groove structures. The seal housing is interposed between a pair of compartments. The seal rings are separately disposed within the seal housing and separately disposed around the rotatable runner. The groove structures are disposed along an outer annular surface of the rotatable runner. A gas is communicable onto the groove structures. Each groove structure includes at least two hydrodynamic grooves that separate and communicate the gas onto the seal rings. Each groove includes steps whereby the depth of at least one adjoining step decreases in the direction opposite to rotation with or without the depth of another adjoining steps increasing in the direction opposite to rotation.

A circumferential seal assembly capable of dividing a gas into separate flow paths before communication between a rotatable runner and a pair of seal rings is presented. The assembly includes an annular seal housing, a rotatable runner, a pair of annular seal rings, and a plurality of groove structures. Each groove structure separates a source flow communicated into a feed groove so that a portion enters at least two grooves to form a longitudinal flow therein. Each groove includes at least two adjoining steps defined by base walls. The base walls are arranged along the groove to decrease depthwise opposite to rotation of the rotatable runner. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects the longitudinal flow to form an outward radial flow in the direction of one annular seal ring. The base walls are bounded by and intersect a pair of side walls. Each side wall includes at least one side shoulder which narrows the groove widthwise and locally redirects the longitudinal flow away from the side wall to form a lateral flow in the direction of the other side wall. Each reduction to the volume of the gas at the downstream end of each groove structure increases pressure and enhances the stiffness of a thin-film layer between each annular seal ring and the rotatable runner.

An air bearing for movably bearing at least two elements includes a bearing main body with a first air outflow channel and a second air outflow channel. The first air outflow channel is supplied with air via at least one first air delivery device. The second air outflow channel is supplied with air via at least one second air delivery device. A sensor detects at least one of a bearing stroke, a bearing pressure, and a bearing throughflow, and a controller adjusts the supply of the air to at least one of the first air outflow channel and the second air outflow channel in accordance with the at least one of the bearing stroke, the bearing pressure, and the bearing throughflow.

A circumferential seal assembly suitable for forming a thin film between a rotatable runner and a sealing ring is presented. The assembly includes an annular seal housing, a rotatable runner, an annular seal ring, and a plurality of groove structures. Each groove structure includes a groove and an optional feed groove. The groove includes at least two adjoining steps defined by base walls arranged to decrease depthwise. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects a longitudinal flow to form an outward radial flow in the direction of the annular seal ring. The base walls are bounded by and intersect a pair of side walls. A side wall includes at least one side shoulder which narrows the groove widthwise and locally redirects the longitudinal flow to form a lateral flow in the direction of the other side wall. Outward and lateral flows separately or in combination enhance stiffness of a thin-film layer between the annular seal ring and the rotatable runner.

A circumferential seal assembly capable of separating a gas into two separate flow paths before communication between a rotatable runner and a pair of seal rings is presented. The seal assembly includes an annular seal housing, a pair of annular seal rings, a rotatable runner, and a plurality of groove structures. The seal housing is interposed between a pair of compartments. The seal rings are separately disposed within the seal housing and separately disposed around the rotatable runner. The groove structures are disposed along an outer annular surface of the rotatable runner. A gas is communicable onto the groove structures. Each groove structure includes at least two hydrodynamic grooves that separate and communicate the gas onto the seal rings. Each groove includes steps whereby the depth of at least one adjoining step decreases in the direction opposite to rotation with or without the depth of another adjoining steps increasing in the direction opposite to rotation. Each groove is also tapered widthwise.

A hydrodynamic thrust bearing for a torque converter comprising: an axis of rotation; a first radial thrust surface; a second radial surface, opposite the first radial thrust surface, including at least two axially protruding anti-rotation pins for preventing relative motion with one of either a stator assembly or an impeller once assembled; an inner circumferential surface defining an opening concentric with the axis of rotation; an outer circumferential surface; and, an axial retention means for attaching to the one of either a stator assembly or an impeller and including at least two resilient tabs, each tab comprising: a deflectable portion; a lockable portion; and, an axial portion having a first width and connecting the deflectable portion and the lockable portion. A torque converter having a hydrodynamic thrust bearing as described is also provided.

A bearing assembly may include a first bearing ring, a second bearing ring, and at least one row of rolling elements having a plurality of rolling elements that are disposed so as to be capable of rolling on a first raceway of the first bearing ring and on a second raceway of the second bearing ring. At least one hydrostatically supported first sliding bearing segment may be disposed on the first bearing ring. Further, the hydrostatically supported first sliding bearing segment may interact with a first bearing face that is disposed on the second bearing ring. The hydrostatically supported first sliding bearing segment may be mounted so as to be movable in a movement direction that is perpendicular to the first bearing face.

A motor according to an embodiment of the present invention includes a rotary shaft; a rotor mounted on the rotary shaft; a stator surrounding an outer periphery of the rotor; an impeller mounted on the rotary shaft to be spaced apart from the rotor; a bearing housing positioned between the impeller and the rotor and formed with a through-hole through which the rotary shaft passes; and a gas bearing disposed in the bearing housing, wherein a thickness of the gas bearing is equal to or greater than 50% of a gap between an inner surface of the bearing housing and an outer peripheral surface of the rotary shaft and is equal to or less than 0.3 mm.

A centrifugal compressor assembly and method of operation provides a motor that drives a first stage compressor. The motor comprises a rotor. The motor uses radial aerostatic bearings to stabilize rotation and axial displacement of the rotor. The motor also uses a thrust aerostatic bearing to balance an axial force of the rotor. The radial aerostatic bearings and the thrust aerostatic bearing use a low-viscous vapor-liquid two-phase fluid as a lubricating medium. The radial aerostatic bearings supports the rotor. The thrust aerostatic bearing uses porous aerostatic bearings that use a low-viscous vapor-liquid two-phase fluid, so as to reduce radial and axial oscillation of the rotor. This enables clearance between a blade tip of an impeller and a volute. This causes a seal clearance to be reduced by a half; thereby increasing efficiency of the centrifugal compressor by at least 10 percent.