A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

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.

An intershaft seal assembly for maintaining separation between a piston ring and a pair of mating rings is presented. The assembly includes a piston ring interposed between forward and aft mating rings and a plurality of hydrodynamic grooves disposed along a sealing face of each mating ring. Each hydrodynamic groove further includes at least two adjoining steps wherein each step is defined by a base wall arranged to decrease depthwise in the direction opposite to rotation of an inner shaft. Two adjoining base walls define a base shoulder which locally redirects potion of a longitudinal flow within the groove to form an outward flow in the direction of the piston ring. Base walls are bounded by and intersect a pair of side walls with at least one side shoulder thereon which narrows the groove widthwise and locally redirects portion of the longitudinal flow to form a lateral flow from one side wall toward another side wall. Outward and lateral flows cooperate, with or without the longitudinal flow, to increase fluid pressure and maintain separation between the piston ring and the mating rings.

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 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 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 heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

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 heat transfer circuit includes a compressor, a condenser, an expander, and an evaporator that are fluidly connected together. The compressor includes a housing and a shaft rotatable relative to the housing to compress a working fluid received at a suction inlet, in which the shaft is supported by a gas bearing, and the gas bearing including a bearing housing having a fluid inlet and an outlet. A high pressure gas source is fluidly connected to the fluid inlet of the bearing housing for supplying high pressure fluid to the fluid inlet of the gas bearing such that the gas bearing supports the shaft when the shaft is rotating. A pressure reducer is connected to the outlet of the gas bearing is provided for reducing a vent pressure of the gas bearing.