A screw vacuum pump comprises a housing forming a pumping chamber, wherein the housing is made of aluminum or an aluminum alloy. Further provided are two screw rotors arranged in the pumping chamber, each screw rotor comprising at least one displacer element having a helical recess for forming a plurality of windings, wherein the at least one displacer element is made of aluminum or an aluminum alloy. Between the region in which prevail 5% to 30% of the outlet pressure and a pressure-side end of the rotor (pump outlet), at least six, particularly at least eight, and with particular preference at least ten windings are provided.

A system for cryocooling an optical sensor on a satellite to a temperature below 200K with minimal vibration comprising a miniature conical rotary screw compressor comprising an inner element configured to only rotate around a first stationary axis and an outer element configured to only rotate around a second stationary axis so that both elements revolve with minimal vibration; with at least one of a) a length of at least one of the inner element and the outer element is between 10 mm and 100 mm; b) a diameter of at least one of the inner element and the outer element is between 2 mm and 45 mm; c) a compression ratio of the rotary screw compressor is between 1:2 and 1:20; and d) a shaft speed of the conical rotary screw compressor is between 1001 and 20000 revolutions per minute.

A gas compression system includes: a first-stage compressor head and a second-stage compressor head; an oil-gas separation vessel; and a sprayer disposed between the first-stage compressor head and the second-stage compressor head and configured to cool inter-stage compressed gas. The sprayer includes: a gas inlet configured to introduce compressed gas; an oil inlet configured to introduce compressor oil; and at least one oil-spraying opening configured to spray oil, which cools the inter-stage compressed gas. With the gas compression system, the sprayer can spray a mixture of oil and gas into the inter-stage compressed gas between the first-stage compressor head and the second-stage compressor head. Accordingly, by intelligently employing a characteristic of containing oil and gas in the scavenge line, an inter-stage heat exchange effect of the sprayer can be enhanced, thereby improving the performance of two-stage compression.

The present disclosure relates to fluid machines, especially compressors, more especially screw compressors. More particularly the present disclosure describes a fluid machine comprising at least one rotor (64), the rotor including a rotor drive shaft (68) extending from the rotor, a housing in which is mounted the rotor, and at least one bearing insert (74) which mounts around the rotor drive shaft at a first end of the rotor and which includes at least one bearing (114) within it and attaches to the housing. The present disclosure also describes bearing inserts suitable for use on such fluid machines.

A secondary airflow path can be provided for a compressor of a compressor system. The secondary airflow path can provide pressurized air to a boost port in communication with a closed compression cell of the compressor.

A supercharged internal combustion engine is drivably connected to a variable displacement supercharger operable to continuously supply varying amounts of an air mass to the engine in response to the varying power requirements of the engine. The variable displacement capability eliminates blowdown losses of fixed displacement superchargers and substantially reduces the need for throttling of the intake air. The device also presents an air-motoring mode that can recover a portion of the engine throttling losses as positive power returned to the engine crankshaft when the engine intake manifold is below atmospheric pressure.

A compressor may include a shell, a compression mechanism, first and second temperature sensors, and a control module. The shell may define a lubricant sump. The compression mechanism may be disposed within the shell and may be operable to compress a working fluid. The first temperature sensor may be at least partially disposed within the shell at a first position. The second temperature sensor may be at least partially disposed within the shell at a second position that is vertically higher than the first position. The control module may be in communication with the first and second temperature sensors and the pressure sensor and may determine whether a liquid level in the lubricant sump is below a predetermined level based on data received from the first and second temperature sensors.

A gear wheel for gear pumps/motors including a plurality of asymmetrical teeth, each tooth including a driving side with a convex shape and mating with a corresponding convex side of a counter-wheel and a discharge side defined, in most of its length, as a cavity of a convex profile. The discharge side is configured so that the radius passing through a tip of the teeth is substantially at least tangent to the discharge side, or intersects the discharge side.

A screw compressor and a chiller unit are provided. An oil separator of the screw compressor may include an outer cylinder, an inner cylinder positioned inside the outer cylinder, and an introducing flow path. The upper end of the inner cylinder is held by the oil separator and the outer wall of the inner cylinder is held independently of the inner wall of the outer cylinder. The diameter of the inner wall of the outer cylinder may gradually be reduced along the swirl flow path. The refrigerant via the introducing passage swirls and goes down along the swirl flow path and is separated into gas refrigerant and oil. The separated gas refrigerant flows from the lower end of the inner cylinder into the inner cylinder and goes up, and the separated oil flows down along the inner wall surface of the outer cylinder.

A gear machine comprises a housing, at least two gearwheels positioned within the housing, and a bearing body defining a circular-cylindrical outer surface segment and a bearing bore. The at least two gearwheels configured to mesh in external engagement with each other. At least one of the gearwheels includes at least one bearing journal rotatably positioned within the bearing bore. The bearing body is positioned within the housing with the circular-cylindrical outer surface segment engaging a corresponding bearing surface defined on the inside of the housing. Each of the at least two gearwheels includes a plurality of tooth tips configured to engage a corresponding sealing surface defined on the inside of the housing. At least one segment of at least one of the sealing surface and the bearing bore is eccentric with respect to the circular-cylindrical outer surface segment of the bearing body. A method of production is also provided.