A rotary positive displacement pump includes a main body rotationally supporting two parallel, axially extending, shafts with gears in constant mesh condition, such that the shafts rotate in opposite directions. A rotor case body is connected to a front side of the main body and has a stationary interior pumping cavity, fluid product inlet and outlet openings, and two cylindrical rotor case hubs each receiving internally one of the shafts. A pair of rotors each have a rotor wing and a rotor drive element that is mounted torque proof on a rotor seat at an end region of one of the shafts. Each rotor seat pair has an axial abutment surface and a mounting surface. The pump also includes fasteners each engaging a mating section of one of the shafts and exerting an axial clamping force on one of the rotor drive elements against one of the axial abutment surfaces.

A positive displacement fluid pump is provided. The fluid pump includes a housing defining an internal cavity. A motor having a drive shaft that rotates about an axis is housed within the internal cavity of the housing. An internal plate is adjacent the motor and includes a central bore through which the drive shaft extends. The fluid pump further includes an external plate including an inlet in fluid communication with a suction port and an outlet in fluid communication with a delivery port. A pumping ring is sandwiched between the internal and external plates, and a pumping arrangement is located within the pumping ring and axially between the internal plate and the external plate. The pumping arrangement is rotatably coupled to the drive shaft such that rotation of the pumping arrangement by the drive shaft causes fluid to be pumped from the suction port to the delivery port.

The invention relates to a metering pump (1) made of plastic, with two rotors (10) coupled to one another via gears (11) and drivable in opposite directions, which are seated in a pump housing (5) equipped with suction ports (6) and outlet ports (7), wherein each rotor (10) has a rotor shaft (12), the rotor shaft ends (15) of which are seated in the walls (8, 4) of the pump housing (5). Each rotor (10) has two rotor blade walls (13) arranged diametrically on the rotor shaft (12), a partially cylindrical rotor blade shoe (14) being formed at each of the peripheral ends of said rotor blade walls, wherein the rotor blade shoes (14) on the one hand contact the cylindrical inside wall regions of the pump housing (5) and on the other contact the rotor blade shafts (13) of the adjacent rotor (10) in a sliding and sealing manner.

Designs for multiple segment lobe pumps are shown. The designs include pumps using rotors having two lobes to a plurality of lobes and segments that include two segments to a plurality of segments. Designs for both vertical, or straight walled conventional lobed rotors, as well as helical lobe rotors are shown. The designs are applicable to a variety of rotors and number of segments. In one particular case the designs enable a three lobe helical pump. Designs are also shown for separation plates used between the multiple segments. The separation float between the pairs of lobes in a segment and can also have a fixed position between the lobes by inclusion of end pieces that enable clamping of the separation plates in position.

A positive displacement fluid pump is provided. The fluid pump includes a housing defining an internal cavity. A motor having a drive shaft that rotates about an axis is housed within the internal cavity of the housing. An internal plate is adjacent the motor and includes a central bore through which the drive shaft extends. The fluid pump further includes an external plate including an inlet in fluid communication with a suction port and an outlet in fluid communication with a delivery port. A pumping ring is sandwiched between the internal and external plates, and a pumping arrangement is located within the pumping ring and axially between the internal plate and the external plate. The pumping arrangement is rotatably coupled to the drive shaft such that rotation of the pumping arrangement by the drive shaft causes fluid to be pumped from the suction port to the delivery port.

A rotary action, self-priming positive displacement constant flow high capacity fluid pump is described. None of the pump parts touch in the pump chamber to minimize pump wear allowing for extended pump life. Since there are no touching parts in the pump chamber, the pump can be operated dry without the pump liquid being present without damage to the pump. The pump may be operated either clockwise or counter-clockwise without loss of positive displacement or reduction in fluids input or output. Due to the design of the pump, the pump is inherently low-maintenance and is highly resistant to clogging by debris and the like. Fluid pressure relief sections are provided by carving out of the inside portions of the housing structure to which the ends of the shaft are mounted to vary or improved pump performance.

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 pump for conveying a fluid includes a casing with a casing inner wall, a pump interior, an inlet opening, an outlet opening, a displacement assembly, and a radial protective element arranged in the pump interior in order to line at least one radial section of the pump interior, the radial protective element bearing against a radial section of the casing inner wall. A fastening element is provided which can be arranged in a fastening position in which the fastening element bears against an edge of the radial protective element and in the process fastens the radial protective element in the pump interior, wherein the fastening element has a longitudinal extent which extends from a first axial end of the pump interior along a recess arranged in the casing inner wall.