A centrifugal-separation type oil separator includes a cylindrical separator body, and an inflow pipe arranged to introduce a fluid including an oil into the separator body. The inflow pipe includes a curved portion. A peripheral wall of the separator body and the inflow pipe include a common portion common to each other.

A screw compressor for a heating, ventilation, and air conditioning (HVAC) system. The screw compressor includes a housing having an inlet end and an outlet end for refrigerant to pass into and out of the housing. A motor is within the housing. A plurality of screw sets are arranged about the motor. The screw sets receive refrigerant entering through the inlet, compress the refrigerant between meshed rotors of the plurality of screw sets, and direct refrigerant out of the housing through the outlet end of the housing.

The present disclosure provides a compressor and an air conditioner. The compressor includes a housing; a first rotating shaft mounted in the housing; a connecting assembly sleeved on the first rotating shaft; and a first rotor assembly including a first rotor and a second rotor coaxially disposed on the connecting assembly. The connecting assembly carries the first rotor and the second rotor to rotate about the first rotating shaft together. The connecting assembly is configured to limit the relative positions of the first rotor and the second rotor, such that there exists a clearance between the first rotor and the second rotor. The present disclosure can maintain a clearance between the first rotor and the second rotor without increasing the number of components of the compressor.

Screw assembly (1) for a triple screw pump (10), comprising: a central screw (2) and at least one lateral screw (3), both provided with one or more helicoidal threads, said lateral screw (3) being arranged to mesh with said central screw (2) with a lateral screw axis (z.sub.1) parallel to the central screw axis (z.sub.c), wherein the distance between the axes of the central screw (2) and of the lateral screw (3) is greater than the half and lower than ? of a central screw (2) external diameter (?.sub.ce).

A fluid machine is provided with a first rotor having a first rotor first working portion and a first rotor second working portion, a second rotor having a second rotor first working portion configured to mesh with the first rotor first working portion and a second rotor second working portion configured to mesh with the first rotor second working portion and rotate independently from the second rotor first working portion.

A rotor unit assembly includes a rotor unit having a chamber and a rotor located within the chamber. The rotor has a piston which extends radially outward from the main body of the rotor; and a valve flange with an aperture. The rotor unit further comprises a rotatable hub, with a cavity configured to receive the piston. The rotor unit further comprises a first low pressure port provided in a path described by the piston; a first high pressure port positioned in a path described by the valve flange aperture around the clearance volume; and a second high pressure port positioned in a path described by the cavity around the hub axis.

The present disclosure provides a method for modifying performance of a rotor profile by adjusting meshing line segments, including the following steps: step 1, dividing a meshing line of a bilateral profile into eight functional segments; step 2, constructing each functional segment by using a cubic NURBS curve; and step 3, locally adjusting the functional segments of the meshing line by adjusting control points or weight factors of the NURBS curve, and observing corresponding changes of the rotor profile so as to adjust corresponding geometrical parameters. The design means is flexible and convenient, the change of the profile is controlled by adjusting the free curve, and the meshing line is locally adjusted in combination with the corresponding relationship between the meshing line and the rotor profile to observe the corresponding change trends, particularly the changes in leak triangle, contact line length, inter-tooth area and area utilization coefficient, of the male and female rotor profile, so that the design efficiency of the rotor profile of a twin-rotor screw compressor is improved, and the defect in the prior art that the rotor profile cannot be locally modified is avoided.

A screw assembly for a triple screw pump includes a central screw and at least one lateral screw, both provided with one or more helicoidal threads. The lateral screw is arranged to mesh with the central screw, with a lateral screw axis being parallel to a central screw axis. The distance between the axes of the central screw and the lateral screw is greater than the half and lower than 3/5 of a central screw external diameter.

The present disclosure provides a compressor and an air conditioner. The compressor includes a housing; a first rotating shaft mounted in the housing; a connecting assembly sleeved on the first rotating shaft; and a first rotor assembly including a first rotor and a second rotor coaxially disposed on the connecting assembly. The connecting assembly carries the first rotor and the second rotor to rotate about the first rotating shaft together. The connecting assembly is configured to limit the relative positions of the first rotor and the second rotor, such that there exists a clearance between the first rotor and the second rotor. The present disclosure can maintain a clearance between the first rotor and the second rotor without increasing the number of components of the compressor.

A screw pump comprising a housing defining a chamber and two screw rotors. Wherein each screw rotor comprises a rotor shaft and at least two displacement elements connected with the rotor shaft. Each displacement element having at least one helical protrusion. One of the displacement elements is a suction-side displacement element arranged in a suction-side section of the chamber. Another one of the displacement elements is a pressure-side displacement element arranged in a pressure-side section of the chamber. The suction-side displacement element is designed tapering in the conveying direction. The clearance between the pressure-side displacement element and the pressure-side section of the chamber at least partly decreases in the conveying direction. Furthermore, a screw rotor, a method of manufacturing a screw rotor and a use of a screw pump or a screw rotor.