A gerotor device for a pump apparatus is disclosed. The gerotor device includes at least two gerotor stages that respectively include an inner rotor rotating during operation about an inner axis with teeth projecting radially outside, and an outer rotor rotating during operation about an outer axis radially offset relative to the inner axis with radially inner open tooth gaps, in which the teeth of the inner rotor engage. A rotor body rotating during operation about a rotor axis includes radially open tooth gaps of a first gerotor stage of the at least two gerotor stages and teeth projecting radially outside of a second gerotor stage of the at least two gerotor stages. The tooth gaps of the at least two gerotor stages are fluidically sealed at least one of against one another and relative to a surrounding area.

A pump apparatus (1) for use in mobile means of transport (100) such as semitrailers, tank trailers, tank semitrailers (101), tank trucks and trucks (102), has a drive motor (40) and a rotary piston pump (2) having two rotor units (10, 20) on rotatably mounted rotor shafts (11, 21), connected to rotor gear wheels (12, 22). A drive pinion (32) of a drive shaft (31) coupled to one of the rotor gear wheels (12) and is received in a recess (81) of the motor shaft (41).

A pump apparatus (1) for use in mobile means of transport (100) such as semitrailers, tank trailers, tank semitrailers (101), tank trucks and trucks (102), has a drive motor (40) and a rotary piston pump (2) having two rotor units (10, 20) on rotatably mounted rotor shafts (11, 21), connected to rotor gear wheels (12, 22). A drive pinion (32) of a drive shaft (31) coupled to one of the rotor gear wheels (12) and is received in a recess (81) of the motor shaft (41).

A method and apparatus for the separation of gas and liquid-solid slurry under pressure, and passage of the liquid-solid slurry to an atmospheric discharge.

A screw spindle pump, including a spindle housing, in which a drive spindle and a running spindle meshing therewith are received in spindle bores. The drive spindle has a cylindrical spindle core and at least two circumferential spindle profiles, and, on an end face, in a depression axially delimited by a planar bottom surface and in which the two profile valleys open out between the two spindle profiles offset by 180°, there is a disk-shaped coupling element, which has an insertion receptacle for a drive shaft of a drive motor and which is coupled to the drive spindle for conjoint rotation therewith via a form-fitting engagement with axially protruding projections that laterally delimit the depression and engage in lateral receptacles of the coupling element. The bottom surface is delimited by the spindle core in the region of the openings of the two profile valleys, and the coupling element has a rounded configuration, corresponding to the shape of the spindle core, in the element regions that adjoin the regions of the opening. The diameter of the coupling element, in the region of the rounded element regions, is no greater than the diameter of the spindle core.

A method of monitoring a volume index valve of a compressor is provided. The method includes recording a first reading of an operating condition of the compressor when the volume index valve is in a first position. The method also includes switching the volume index valve to a second position. The method further includes recording a second reading of the operating condition of the compressor when the volume index valve is in the second position. The method yet further includes calculating a difference between the first reading and the second reading. The method also includes comparing the difference to a predetermined threshold difference to determine if the volume index valve is moving between the first position and the second position in a desired manner.

A method of monitoring a volume index valve of a compressor is provided. The method includes recording a first reading of an operating condition of the compressor when the volume index valve is in a first position. The method also includes switching the volume index valve to a second position. The method further includes recording a second reading of the operating condition of the compressor when the volume index valve is in the second position. The method yet further includes calculating a difference between the first reading and the second reading. The method also includes comparing the difference to a predetermined threshold difference to determine if the volume index valve is moving between the first position and the second position in a desired manner.

Pump (1) comprising:—means (2) for pumping a working fluid;—an electric motor (3) for actuating the pumping means (2); said motor (3) comprising a stator (31) and a rotor (32) that interact for the actuation of the pumping means (2); said rotor (32) being rotatable about an axis of rotation (320);—an electronic unit (4) for controlling the electric motor (3);—a conduit (5) for the delivery of the working fluid downstream of the pumping means (2);—a line (6) for cooling the electric motor (3) and the electronic unit (4), said cooling line (6) being permanently open and drawing off some of the working fluid processed by the pumping means (2). The cooling line (6) comprises a first conduit (61) which is developed from a delivery area (22) of the pumping means (2).

A rotor is shown with an asymmetrical structure for a pump, wherein the rotor includes at least one cutting edge and at least one rounded edge, as well as the pump as such including one or more rotor(s). The rotor (1) has a first circular element (4) where a material-moving cavity (5) is provided in the first circular element (4).

A motor-driven Roots pump includes a housing, a drive shaft and a driven shaft that have axial lines parallel with each other, and a gear chamber. The housing includes a first partition that has a first defining surface, a second partition having a second defining surface, and a relief recess. An addendum circle of the drive gear and an addendum circle of the driven gear intersect with each other at a first intersection point. A plane that includes both the axial lines is defined as an imaginary plane. The first intersection point is located on a side of the imaginary plane on which the drive gear and the driven gear start meshing with each other. An opening of the relief recess is opposed to the first intersection point and is arranged in a region on a side of the imaginary plane on which the first intersection point is located.