A fluid compressor system has a scavenge loss limiter that increases the efficiency of the fluid compressor system by reducing the compressed working fluid recirculated into the airend through a scavenge flow. The scavenge loss limiter includes a scavenge hole positioned at a discharge end face of a rotor cavity of the compressor housing. As a rotor of the compressor system rotates, the rotor may intermittently restrict the free-flowing scavenge flow returning from a lubricant separation tank. The rotor may be a male rotor having a plurality of male lobes. As the discharge end clearance between the rotor and the discharge end face is tightly controlled and monitored, a better control of the scavenge flow returning to the rotor cavity is achieved.

The invention relates to a pump, a pump system and a method for pumping a medium. The pump for pumping medium comprises an inlet, an outlet, a drivable spindle and at least two follower spindles, wherein the drivable spindle and the at least two follower spindles are provided at a mutual angle to each other.

A compressor, including: a first rotor being rotatable around a first axis, the first rotor including a first portion and a second portion; and a first shaft carrying the first portion and the second portion, the first shaft having a first end and a second end that are oppositely arranged. The first rotor is configured to be applied with a preset acting force in a direction from the first end toward the second end or from the second end toward the first end during rotation. The size of the compressor can be reduced with the displacement of the compressor remaining substantially unchanged.

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.

A fluid compressor system has a scavenge loss limiter that increases the efficiency of the fluid compressor system by reducing the compressed working fluid recirculated into the airend through a scavenge flow. The scavenge loss limiter includes a scavenge hole positioned at a discharge end face of a rotor cavity of the compressor housing. As a rotor of the compressor system rotates, the rotor may intermittently restrict the free-flowing scavenge flow returning from a lubricant separation tank. The rotor may be a male rotor having a plurality of male lobes. As the discharge end clearance between the rotor and the discharge end face is tightly controlled and monitored, a better control of the scavenge flow returning to the rotor cavity is achieved.

The disclosure relates to a screw pump (2) comprising: a casing (3) with an inlet (30), an outlet (31) and a flow chamber (32) between the inlet and the outlet, and at least two screws (4, 5, 6) housed in the flow chamber to force a fluid flow 5 through the flow chamber from the inlet to the outlet, wherein each screw (4, 5, 6) comprises a release coupling (45, 52, 62) to restrict, when in use, the rotation of the screw when it is being extracted from a molding tool.