Provided is a scroll compressor that can prevent liquid from being accumulated, the scroll compressor including: a fixed scroll; an orbiting scroll; and a rotation shaft that extends in the horizontal direction and causes the orbiting scroll to orbit relative to the fixed scroll. Liquid is injected into a working chamber. An enclosing point of a working chamber formed near the outer end of a fixed wrap of the fixed scroll is positioned below a center of the rotation shaft and at the lowest point of the contour of the working chamber having shifted to the lowest position. The fixed scroll has an inclined wall surface that is positioned below the center of the rotation shaft, is made to face upward, and extends from the dust wrap to the outer end of the fixed wrap. The inclined wall surface is formed so as to be sloped down gradually from the dust wrap toward the outer end of the fixed wrap.

A water-ring vacuum pump including a built-in hogging flow path. The water-ring vacuum pump includes a first-stage body, a second-stage body, and an impeller. The first-stage body includes a gas inlet port through which gas is suctioned and a seal water supply port through which seal water is supplied. The second-stage body includes a mixed fluid outlet port through which a mixed fluid of the gas and the seal water is discharged. The first-stage body has a fluid-mixing space provided therein, the fluid-mixing space having a mixed flow of the gas and the seal water therein. The second-stage body has a fluid guide space and an internal hogging flow path provided therein, the internal hogging flow path communicating with the fluid guide space.

A water-ring vacuum pump including a built-in hogging flow path. The water-ring vacuum pump includes a first-stage body, a second-stage body, and an impeller. The first-stage body includes a gas inlet port through which gas is suctioned and a seal water supply port through which seal water is supplied. The second-stage body includes a mixed fluid outlet port through which a mixed fluid of the gas and the seal water is discharged. The first-stage body has a fluid-mixing space provided therein, the fluid-mixing space having a mixed flow of the gas and the seal water therein. The second-stage body has a fluid guide space and an internal hogging flow path provided therein, the internal hogging flow path communicating with the fluid guide space.

A compressor includes a casing, a compression mechanism, and a motor that drives the compression mechanism. The casing is configured to cover an internal space. The internal space includes a first space and a second space larger than the first space. The casing has a first casing part covering the first space and a second casing part covering the second space. At least one of the first space and the second space is a high-pressure space configured to contain high-pressure fluid. A metallic coating may be formed on an outer surface of at least the first casing part. Alternatively, a resin coating may be formed on an outer surface of the casing.

The present invention discloses a scroll compressor. At least two shrink belts (23′, 23″, 26, 26′, 28, 28′) are provided around the outer periphery of said fixed scroll between the outer periphery of said fixed scroll (2) and the inner wall surface of the upper cap (1) of the scroll compressor. The at least two shrink belts are annular, and are in interference fit between the outer periphery of said fixed scroll and the inner wall surface of the upper cap. The at least two shrink belts include a main shrink belt (23′, 23″, 28) and an assistant shrink belt (26, 26′, 28′). The main shrink belt and the assistant shrink belt are arranged side by side in the axial direction, that is, in the vertical direction of the fixed scroll, and the main shrink belt and the assistant shrink belt are spaced apart from each other by a distance. In this way, it is allowed to add other special structure (e.g., an additional fluid passage) to the fixed scroll, reduce the deformation of the fixed scroll, and improve the performance and the reliability of the scroll compressor.

A vacuum pump system is provided that includes a main vacuum pump that is connected to a chamber that is to be evacuated. An auxiliary pump is connected to an outlet of the main vacuum pump. Furthermore, a sealing gas supply device is connected to the main vacuum pump. The sealing gas supply device is switched on and off with the aid of a control device as a function of a predetermined control variable. Additionally, a method for controlling the vacuum pump system.

A vacuum pump system is provided that includes a main vacuum pump that is connected to a chamber that is to be evacuated. An auxiliary pump is connected to an outlet of the main vacuum pump. Furthermore, a sealing gas supply device is connected to the main vacuum pump. The sealing gas supply device is switched on and off with the aid of a control device as a function of a predetermined control variable. Additionally, a method for controlling the vacuum pump system.

A liquid-injected compressor or vacuum pump device with a liquid-injected compressor or vacuum pump element (2),which includes a liquid return system (7), a motor (4) to drive the compressor or vacuum pumping element (2), a gearbox (3) provided between the motor (4) and the liquid-injected compressor or vacuum pump element (2), and a liquid separator vessel (5) in fluid connection with an outlet (6) of the compressor or vacuum pump element (2). The liquid return system (7) includes a main body (8) with a chamber in which a first compressed gas flow (11) from the liquid separator vessel (5) and a second fluid flow (15) from the gearbox (3) are mixed together to form a third fluid flow (20). The third fluid flow (20) leaves the chamber via an outlet (16) and is directed into the liquid-injected compressor or vacuum pump element (2) via the injection point (17).

A rotary pump, preferably a vacuum pump, featuring: a delivery space including an inlet on a low-pressure side and an outlet on a high-pressure side of the pump; a rotor which is arranged in the delivery space and delivers a fluid from the inlet into the delivery space to the outlet from the delivery space; at least one housing part which delineates the delivery space at least axially; and a drive shaft which is connected in drive terms to the rotor; including at least one sealing element which is connected, secured against shifting and/or rotating, to the drive shaft and/or rotor and forms a radial sealing gap with the housing part.

A control system comprising: a suction line; an exhaust line; an operating liquid line; a liquid ring pump comprising a suction input coupled to the suction line, an exhaust output coupled to the exhaust line, and a liquid input coupled to the operating liquid line; one or more regulating devices configured to control flow of the operating liquid into the liquid ring pump; a first sensor configured to measure a first parameter of an exhaust fluid of the liquid ring pump; a second sensor configured to measure a second parameter of an operating liquid received by the liquid ring pump; and a controller operatively coupled to the sensors and the regulating device(s), and configured to control the regulating device(s) based on measurements by the sensors.