One or more techniques and/or systems are disclosed for a pump technology that provides for more effective and efficient transfer of liquids, such as petroleum products and components, to and through pipelines. Such a technology can comprise a type of external gear pump that creates higher flow, resulting in higher pressures in the pipeline, to move the liquids, while providing for longer pump life, simpler and less maintenance, and fewer undesired conditions, with a smaller footprint, in a cost-effective system.

In order to adapt to different operating conditions a screw expander, comprising an expander housing with a screw rotor chamber arranged therein, two screw rotors arranged in the screw rotor chamber and mounted rotatably in the expander housing, which screw rotors intermesh with their screw contours in order to receive working medium supplied by means of a high-pressure chamber arranged in the expander housing and in order to discharge said medium in the region of a low-pressure chamber arranged in the expander housing, and a generator driven by the screw rotors, it is proposed that the screw expander has at least one control slide, which is arranged in a slide channel of the expander housing and is adjacent to both screw rotors with slide wall surfaces, which control slide is movable in a displacement direction parallel to the screw rotor axes and is thereby configured to influence the final volume and/or the initial volume, and that a slide drive is provided for moving the control slide into different slide positions.

Disclosed are an oil separation structure and a compressor. The oil separation structure includes a housing and a filtering screen. A core is disposed at a center of the housing, and a plurality of guiding members for guiding gas flow are provided along circumferential directions of the core. The filtering screen is disposed on a periphery of the housing, and a cavity is formed between the filtering screen and the core. The housing is provided with a gas inlet and a gas outlet which are in communication with the cavity, and the gas inlet is configured to introduce the gas flow into the cavity; the guiding members are configured to guide the gas flow to rotationally flow around the core, and the gas outlet is configured to discharge the gas flow from the cavity.

Provided is a co-rotating scroll compressor comprising a synchronous drive mechanism that can achieve a long life. The compressor comprises a driving side scroll member (90) driven to rotate about a driving side rotation axis CL1, a driven side scroll member (70) driven to rotate about a driven side rotation axis CL2, a hollowed drive shaft (6) that is connected to the driving side scroll member (90), and driven by a motor (5) to rotate, and a driven shaft (20) that is disposed inside the drive shaft (6), and has one end connected to the drive shaft (6) via a first flexible coupling (21) and the other end connected to the driven side scroll member (70) via a second flexible coupling (22).

A pumping system is provided, including a rough-vacuum pump; a Roots vacuum pump including a pumping stage having a stator inside which two Roots rotors are configured to rotate synchronously in opposite directions to drive a gas to be pumped between an inlet orifice and an outlet orifice; and a pipeline connecting the outlet orifice to an intake of the rough-vacuum pump, a shortest distance between an edge of the outlet orifice and each of the Roots rotors in the pumping stage being less than 3 cm, and the outlet orifice being situated at the end of an upstream tube of the pipeline that passes into the pumping stage.

A scroll compressor includes a hermetic container, a fixed scroll, a swing scroll, a frame, an electric motor, and a shaft. A first groove and a second groove are provided outside a fixed wrap in a radial direction at an end plate surface of the fixed scroll. An oil supply hole for guiding lubricant oil from a through-hole opens at an end plate surface of the swing scroll. A single opening of the oil supply hole alternately communicates with the first groove and the second groove along with swing of the swing scroll.

The invention relates to a method for controlling a rotary screw compressor, having at least a first and a second air-end, wherein both air-ends are driven separately from one another and speed controlled. According to the invention, the following steps are carried out: detection of a volume flow taken at the outlet of the second air-end; adjustment of the rotational speed of both air-ends, when the removed volume flow fluctuates in a range between a maximum value and a minimum value; opening of a pressure-relief valve, if the volume flow falls below the minimum value; and reduction of the rotational speed of at least the first air-end to a predetermined idling speed (V1.sub.L) to reduce the volumetric flow delivered by the first to the second air-end.

A scroll compressor includes a balancer that rotates integrally with a rotary shaft. A bushing includes a cylindrical portion and an auxiliary weight portion. The auxiliary weight portion is arranged on the outer side of the cylindrical portion. The fitting hole is provided at a position where a moment about the eccentric shaft generated by a centrifugal force acting on the movable scroll due to rotation of the rotary shaft and a moment about the eccentric shaft generated by a centrifugal force acting on the auxiliary weight portion due to rotation of the rotary shaft are in the opposite directions. As viewed in the axial direction of the rotary shaft, the center of gravity of the bushing is located on the same side of a straight line including the center of the cylindrical portion and the center of the rotary shaft as the center of the eccentric shaft.

A scroll compressor with oil return unit, having a fixed spiral and an orbiting spiral, which compresses gas from a suction-pressure chamber into a high-pressure chamber. A counter-pressure chamber is connected to the orbiting spiral and the orbiting spiral presses onto the fixed spiral. The oil return unit has a counter-pressure spiral nozzle having a high-pressure channel connected to an end face for oil supply. A suction-pressure spiral nozzle with a suction-pressure channel connected to the end face discharges oil into the suction-pressure chamber. A counter-pressure channel is arranged between the counter-pressure spiral nozzle and the suction-pressure spiral nozzle for discharging oil into the counter-pressure chamber.

A vacuum pumping system includes a plurality of positive displacement vacuum pumps, and more particularly a plurality of positive displacement vacuum pumps working in parallel. The vacuum pumping system includes a management unit that carries out a synchronized control of all the positive displacement vacuum pumps of the vacuum pumping system and thus allows to check possible risk of contamination of the vacuum pumping system and carry out, if needed, the necessary corrective actions without requiring any modification to the construction of the vacuum pumping system.