A sealing arrangement for a sliding vane machine for compressing or expanding a fluid, for sealing between a rotating plane surface on a rotor and a machine housing to prevent flow of process fluid between an internal volume to an external volume of said vane machine a seal pocket located at a housing end and said seal pocket opens towards the direction of the external volume and the internal volume, an assembly arranged for mounting in said seal pocket, said assembly comprising: a piston arrangement, a sealing bearing ring between said piston arrangement and said plane surface, a fluid supply line for a pressurized lubrication fluid through said housing to a piston cavity, said piston arrangement further having piston fluid channels and said bearing sealing ring having lubrication conduits through said bearing seal ring, corresponding with said piston fluid channels, said pressurized lubrication fluid arranged for moving said piston against said sealing bearing ring and thus moving said sealing bearing ring against said sealing surface thus forming a sealing arrangement.

Some embodiments are directed to a positive displacement pump having an eccentric piston, comprising a tube having a first end and a second end that is terminated by a cylinder secured to a delivery zone, the tube including an intake opening and a delivery opening, a drive shaft extending between the transmission zone and the tube, a piston arranged in the delivery zone and mounted in a sliding manner at the end of the shaft, being pressed against the cylinder by an elastic presser so as to prevent fluid displacement between the tube and the delivery zone when the pump is dry, and the elastic presser is provided to press the piston against the cylinder when the pump is running under load.

A hydraulic machine is described having a first part (2) and a second part (3) moveable relative to said first part (3), one of said first part (2) and said second part (3) having a first land (9) resting against the other one of said second part (3) and said first part (2), having a predetermined first height (H1), and being arranged between a high pressure area (7) and a low pressure area (8). Such a machine should have a long working life. To this end a second land (10) having a predetermined second height (H2) smaller than said first height (H1) is located adjacent to said first land (9).

An eccentric screw pump for pumping fluids or flowing conveying media from a suction side to a pressure side, which includes a rotor and a stator, the stator being flexible and is connected to the pump housing on one side, in particular on the suction side. The rotor is connected to the drive shaft by means of an articulation. When the eccentric screw pump is in the idle state, there is no sealing contact at least in areas between the rotor and the stator in the sealing areas. When the eccentric screw pump is in the operating state, the stator is surrounded, at least in sections and/or, essentially, on the periphery by the conveying medium. The rotor and the stator are brought into contact with each other in the operating state along the sealing area.

A mounting hub operable to connect a flexible impeller to a drive shaft. The mounting hub is detachable from the impeller, and is adapted to permit the impeller to be decoupled rotationally from the impeller drive shaft during installation, and then recoupled rotationally once the flexible impeller is in position.

A lobe pump is provided. The lobe pump may include a housing having an inlet and an outlet for a medium to be pumped, at least one lobe mounted in the housing so as to be drivable and rotatable and which has at least two conveying vanes, and at least one sealing element per lobe mounted on a sealing body. The at least one sealing element runs over a contour of the at least one lobe during rotation of the at least one lobe and performs an outward travel movement from a minimum diameter of the at least one lobe to a maximum diameter of the at least one lobe and an inward travel movement from the maximum diameter of the at least one lobe to the minimum diameter of the at least one lobe on different sides of each of the at least two conveying vanes.

A dual-spindle screw pump having a pump housing (11) for a medium to be conveyed, in particular a foodstuff, which has a pump section (12), at least one bearing section (16) and at least one gear section (17), wherein the at least one bearing section (16) and the pump section (12) are constructed separately from one another, wherein the pump section is a product chamber (26) through which the medium is conveyed, having a conveyor housing part (13) as a constituent part of the pump section (12) in which two conveying screws (20, 21) that are arranged on shafts (18, 19) are provided, having at least one feed section (22) and at least one removal section (23) as constituent parts of the pump section (12), preferably each having a connection flange (24, 25), wherein the product chamber (26) has at least one parting line (28) having a connection to the surrounding atmosphere (29), which is provided with a vapor barrier (30) having a groove (31) as the vapor channel (38), characterized in that there is provided in the groove (31) at least one seal (40) which seals the vapor channel (38) off from the product chamber (26) and from the surrounding atmosphere (29).

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.

The present invention relates to improvements in the area of flexible impeller pumps. In particular, the present invention relates to flexible impellers with improved profiles (such as dual sealing lips), which are particularly well-suited to multiple cam pumps. A novel mounting hub configuration for mounting an impeller on a drive shaft is also provided. Pumps comprising such impellers and/or mounting hubs are provided, as are associated methods of installation and removal.

An internal gear pump (100) comprises: a rotor/torque ring comprising an internally lobed (140) rotor (130) and a torque ring (120) extending beyond at least a first end (134) of the rotor; an externally lobed (160) idler (150) encircled by the rotor; a hollow shaft (190) supporting the idler; a pressure relief element (200) positioned to shift between a first condition and a second condition; and a spring (210) biasing the pressure relief element toward the first condition from the second condition. The torque ring has at least one pressure relief port (240A, 240B) positioned so that: in the first condition, the pressure relief element blocks a path from an interior volume (235) of the pump to the pressure relief port; and in the second condition, relative to the first condition the pressure relief element does not block the path.