A compressor assembly, a vapor compression system incorporating the same, and a method for operating the vapor compression system are provided. The compressor assembly includes a motor for driving a rotating shaft, a foil bearing for supporting the rotating shaft, a compression mechanism for increasing the pressure of a working fluid, a supply line in fluid communication with the compression mechanism, and a heating apparatus for heating the working fluid. The supply line is configured for injecting the working fluid (e.g., from downstream of the compression mechanism) toward the foil bearing. The method provides for the monitoring of the temperature of the working fluid. When the temperature of the working fluid is less than 3° F. of superheat it is heated prior to being injected toward the foil bearing. The heating of the working fluid prevents, or at least mitigates, liquid from being transferred to the foil bearing.

A bearing assembly for stabilizing rotation of a rotatable element includes a gas bearing acting as a bearing for the rotatable element. An ultrasonic vibration pump is coupled to the gas bearing for providing pressurized gas to the gas bearing, and a sealed housing encloses the gas bearing and the ultrasonic vibration pump. Also described is a reaction wheel assembly for a spacecraft. The reaction wheel assembly includes a reaction wheel and the bearing assembly for stabilizing rotation of the reaction wheel.

A method (100) for operating a gas bearing (1), wherein the gas bearing is formed by a rotor (11) and a stator (12), wherein when there is rotation against a stator (12) with a lift-off rotational speed n.sub.L the rotor (11) changes from mixed friction with the stator (12) into fluid friction with a medium (13) located between the stator (12) and the rotor (11), wherein the rotational speed of the rotor (11) is kept at or above an idling rotational speed n.sub.I, wherein—in response to a first information item (21), on the basis of which a change ΔF is to be expected in the acceleration forces F acting on the gas bearing (1), a new value of a safety factor r.sub.N:=n.sub.I/n.sub.L between the idling rotational speed n.sub.I and the lift-off rotational speed n.sub.L is determined (110), and/or—in response to a second information item (31), on the basis of which a change Δn.sub.L is to be expected in the lift-off rotational speed n.sub.L, a new value n.sub.L,neu is determined for the lift-off rotational speed n.sub.L (120), wherein the idling rotational speed n.sub.I of the gas bearing (1) is adapted to the changed value of the safety factor r.sub.N, and/or to the changed value n.sub.L,neu of the lift-off rotational speed n.sub.L, (130). The invention further relates to an associated computer program.

Provided is a linear compressor including a linear motor having a mover reciprocating with respect to a stator; a piston coupled to the mover to reciprocate; a cylinder into which the piston is slidingly inserted, the cylinder having an inner circumferential surface forming a bearing surface together with an external circumferential surface of the piston, the cylinder forming a compression space together with the piston, and the cylinder having at least one first hole formed through the inner circumferential surface of the cylinder and an outer circumferential surface of the cylinder to guide refrigerant discharged from the compression space to the bearing surface; and a porous member inserted into the outer circumferential surface of the cylinder and configured to cover the first hole, the porous member having multiple micropores smaller than the first hole.

A porous gas bearing is disclosed. The porous gas bearing includes a housing having a fluid inlet and an aperture. A porous surface layer is disposed within the housing surrounding the aperture in a circumferential direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a damping system including a biasing member, the biasing member being disposed in a passageway that extends along the longitudinal direction of the aperture and circumferentially about the aperture, wherein the biasing member is arranged radially outward from the porous surface layer.

Provided are a bearing detection method, a bearing detection system, a method for starting a gas turbine and a system for starting a gas turbine. The bearing detection method includes: starting a rotor to enable the rotor to rotate at a first rotating speed along a first direction, wherein the first direction is a rotating direction when the rotor operates normally, and the first rotating speed is a calibration value; acquiring a first torque, wherein the first torque is an output torque when the rotor rotates at the first rotating speed along the first direction; and judging the first torque and a torque threshold value, wherein the torque threshold value is a calibration value, and if the first torque is smaller than the torque threshold value, it is judged that a bearing is fault-free.

A fluid cushion guiding device (1) is provided for guiding a member (2) into relative movement, rotary and/or translatory, relative to the guiding device (1). The guiding device (1) comprises an inner cylindrical portion (10) and an outer cylindrical portion (11) that are coaxial with each other. The inner cylindrical portion (10) has a plurality of radial holes (12) having first ends (13) communicating with a first gap (15) provided between the inner cylindrical portion (10) and the member (2) to be guided. The outer cylindrical portion (11) has at least one radial opening (17) arranged to allow introducing from the outside a pressurised fluid which, by reaching the first gap (15) through the holes (12), is suitable to create a fluidic gap between the inner cylindrical portion (10) and the member (2) to be guided.

A turbo compressor assembly of a cooling machine has a shaft mounted in a common housing with first and second radial dynamic gas bearings and a thrust bearing. A supply stream of working gas supplied to the first radial bearing is formed between an inner wall of a compressor body and the shaft, and a supply stream of working gas from a turbo expander supplied to the second radial bearing and to the thrust bearing is formed between an inner wall of a turboexpander body and the shaft. The first radial dynamic gas bearing is sealed towards the electric motor rotor by a shaft seal. A surface in a shape of an annulus is formed on the shaft between the first radial bearing and the shaft seal, the annulus perpendicular to an axis of the shaft and functioning as a piston for balancing an axial force acting on the shaft.

A method (100) for operating a gas bearing (1), wherein the gas bearing is formed by a rotor (11) and a stator (12), wherein when there is rotation against a stator (12) with a lift-off rotational speed n.sub.L the rotor (11) changes from mixed friction with the stator (12) into fluid friction with a medium (13) located between the stator (12) and the rotor (11), wherein the rotational speed of the rotor (11) is kept at or above an idling rotational speed n.sub.I, wherein in response to a first information item (21), on the basis of which a change F is to be expected in the acceleration forces F acting on the gas bearing (1), a new value of a safety factor r.sub.N:=n.sub.I/n.sub.L between the idling rotational speed n.sub.I and the lift-off rotational speed n.sub.L is determined (110), and/or in response to a second information item (31), on the basis of which a change n.sub.L is to be expected in the lift-off rotational speed n.sub.L, a new value n.sub.L,neu is determined for the lift-off rotational speed n.sub.L (120), wherein the idling rotational speed n.sub.I of the gas bearing (1) is adapted to the changed value of the safety factor r.sub.N, and/or to the changed value n.sub.L,neu of the lift-off rotational speed n.sub.L, (130). The invention further relates to an associated computer program.

A porous gas bearing is disclosed. The porous gas bearing includes a housing having a fluid inlet and an aperture. A porous surface layer is disposed within the housing surrounding the aperture in a circumferential direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a damping system including a biasing member, the biasing member being disposed in a passageway that extends along the longitudinal direction of the aperture and circumferentially about the aperture, wherein the biasing member is arranged radially outward from the porous surface layer.