A screw compressor is provided which can reduce the pressure loss in a suction flow passage. A casing 12 of the screw compressor includes a bore 21 that accommodates a lobed portion 13A of a male rotor 11A and a lobed portion 13B of a female rotor 11B therein such that working chambers are formed in lobe grooves of the lobed portions, a suction port 22 located on an outer side in a rotor radial direction, and a suction flow passage 23 that communicates in a rotor axial direction with working chambers that are in a suction stroke. The suction flow passage 23 includes a male rotor side suction flow passage 26A located on an male rotor 11A side and besides on a downstream side with respect to a virtual plane C, and a female rotor side suction flow passage 26B located on an female rotor 11B side and besides on the downstream side with respect to the virtual plane C. The male rotor side suction flow passage 26A is formed such that a flow passage wall 27A on the outer side in the rotor radial direction is located at a position that is the same as that of a wall of the bore 21 as viewed in the rotor axial direction at least within a range of one half of an axial pitch P1 of the lobed portion 13A of the male rotor 11A from a suction side end surface of the lobed portion 13A in the rotor axial direction.

A housing for a rotary vane pump includes a suction flange and a discharge flange having a multi-angular cross-section with at least two sides extending parallel to each other, cooling ribs provided on an outer surface of the housing, with the number of cooling ribs in the region with a high internal pressure being greater than a number of cooling ribs in the region with a low internal pressure, inlet and outlet, with the inlet cross-section being greater than the outlet cross-section, and connection elements provided on the housing and each having two installation surfaces connected by a connection surface.

A compressor includes a shell, a compression mechanism and a fitting. The shell includes an opening and defines a chamber. The compression mechanism is disposed within the chamber of the shell. The fitting is attached to the shell at the opening. Working fluid flowing through the fitting flows to the compression mechanism. The opening is partially defined by a first edge and a second edge. The first edge includes a first planar surface and the second edge includes a second planar surface that faces the first planar surface. A first portion of the fitting extends at least partially into the opening and a second portion of the fitting abuts against the first and second edges.

A dual-section gear pump that enhances compactness of the design includes two pump sections separated by a divider. Each pump section includes a pump cavity and a gear set configured to convey fluid from an intake side to a discharge side of the respective pump cavities. The divider includes a fluid flow passage that enables the two pump sections to share common intake flow via the flow passage provided across the divider. The divider also is configured to enable each gear set in each pump section to provide independent pressurization of the fluid in each pump section, which is discharged from each pump cavity via separate outlets. The gear pump is configured to provide suitable sealing between each pump section and support of the respective gear sets in each pump section while enhancing compactness of the design.

A fixed scroll for a scroll compressor includes a plurality of pillar portions extending axially from a first face of the fixed scroll to an opposing second face thereof. Each of the plurality of the pillar portions is spaced radially outwardly of a spiral structure at least partially defining a compression chamber of the scroll compressor. The fixed scroll further includes an annular array of spaced flow openings into the compression chamber of the scroll compressor with each of the flow openings formed between adjacent ones of the pillar portions.

This rotary compressor comprises: a casing forming the outer shape; a rolling piston configured to rotate eccentrically in an internal space; a vane configured to contact the rolling piston and divide the internal space into a suction chamber and a compression chamber; and a main suction port connecting the suction chamber to an outside of the cylinder. The rotary compressor also comprises: a cylinder disposed inside the casing; a first flange disposed above the cylinder; and a second flange disposed below the cylinder. The main suction port comprises a sub suction port extending in a direction in which at least one among the first flange and the second flange is disposed, and at least one among the first flange and the second flange has a flow path groove connecting the sub suction port and the suction chamber.

A rotary piston pump, in particular a claw pump, includes a housing which, when placed in a customary manner, has a housing inlet in a housing upper side. In order to further improve a rotary piston pump in a beneficial way, the housing inlet is connected to a gas channel that is integrated in the housing and extends transversely to a rotational axis of the piston, which gas channel creates a flow connection to a gas outlet of a filter part arranged in a filter receptacle. In the installed state, the filter part is accessible from a side perpendicular to the housing upper side, for maintenance purposes, for example.

A compressor including a compression unit comprising an inlet for sucking gas and configured to compress the sucked gas; and a casing configured to accommodate the compression unit; and a suction guide comprising a passage for guiding the gas from an outside of the casing to the inlet. The compression unit includes a first surface extending from an edge of the inlet, the suction guide includes a second surface extending from an edge of a vent of the passage, and provided in an internal area of the casing to make the first surface and the second surface face each other, and an external end of the first surface and an internal end of the second surface or an internal end of the first surface and an external end of the second surface do not overlap along a direction of an axis of the compressor.

A rotary piston pump, in particular a claw pump, includes a housing which, when placed in a customary manner, has a housing inlet in a housing upper side. In order to further improve a rotary piston pump in a beneficial way, the housing inlet is connected to a gas channel that is integrated in the housing and extends transversely to a rotational axis of the piston, which gas channel creates a flow connection to a gas outlet of a filter part arranged in a filter receptacle. In the installed state, the filter part is accessible from a side perpendicular to the housing upper side, for maintenance purposes, for example.

A vacuum pump is provided that includes rotor elements arranged in a suction chamber. An outlet duct is connected to an exhaust pipe. For the purpose of silencing, sound expansion spaces are provided in the outlet duct, which are integrated into the pump housing. Alternatively or in addition to these sound expansion spaces, sound expansion spaces may be provided in an inlet duct which is used for the inlet of gas ballast, said sound expansion spaces being preferably likewise integrated into the pump housing.