An improved screw pump such as, for example, a twin screw pump, includes a casing including an internal chamber, and first and second rotors rotatably positioned within the chamber of the casing. The first and second rotors have an intermeshing threaded-shape profiling. A plurality of bearing seal assemblies are provided at each end of the first and second rotors. Each bearing seal assembly includes a bearing positioned about an end portion of a rotor to facilitate rotation of the rotor, and a seal positioned about an end portion of a rotor to seal passage of the rotor through the casing. The bearing is coupled to the seal so that the seal may be secured to the casing via the coupling of the bearing to the casing.

The present invention relates to a device (1, 30) for the recirculation of an at least partially gaseous composition containing hydrogen, wherein the device (1, 30) is a dry rotary pump comprising a first rotating shaft (13) and a second rotating shaft (14) driving respectively a first piston with claws (8) and a second piston with claws (9) in rotation in a pumping chamber (2) comprising an inlet orifice (11) and an outlet orifice (10) for the gaseous composition, the first rotating shaft (13) and the second rotating shaft (14) being configured to be driven in rotation by a drive system (17,18) situated in a gear chamber (4), wherein the device (1, 30) comprises a first pair of seals (19) and a second pair of seals (20), each comprising a first shaft seal (19a, 20a) and a second shaft seal (19b, 20b), the first pair of seals (19) being provided around the first rotating shaft (13) and the second pair of seals (20) being provided around the second rotating shaft (14) between the pumping chamber (2) and the gear chamber (4), wherein the device (1, 30) comprises a pressure equalization chamber (25) which is in fluid connection with a gap (24) present between the first shaft seal (19a, 20a) and the second shaft seal (19b, 20b) of the first and of the second pair of seals (19, 20) to regulate the pressure in the gap (24), wherein the gear chamber (4) is in fluid connection with the gap (24), and wherein the pumping chamber (2) is in fluid connection with the first shaft seal (19a) of the first pair of seals (19) and with the first shaft seal (20a) of the second pair of seals (20) by means of a pulsation attenuation chamber (22). The present invention also relates to a fuel cell system (40, 50, 60, 70, 80, 90) comprising a device for recirculation according to the present invention.

A compressor includes a shell, a first scroll member, a second scroll member and a sealing assembly. The shell defines a first pressure region and a second pressure region. The first scroll member is disposed within the shell and includes a first end plate and a first scroll wrap. The second scroll member includes a second end plate and a second scroll wrap. The second scroll wrap meshingly engages the first scroll wrap to define a compression chamber therebetween. The seal assembly fluidly separates the first and second pressure regions from each other. The seal assembly includes a first plate, a second plate, a first sealing member and a second sealing member. The first sealing member is sealingly engaged with the first plate and the second plate. The second sealing member is sealingly engaged with the first sealing member and the first plate.

A tip seal 1 for a scroll compressor capable of reducing a frictional force between scroll members and the tip seal where the tip seal 1 has a spiral shape for sealing a compression chamber formed between a fixed scroll and a movable scroll in a scroll compressor provided with the fixed scroll. The movable scroll having a plurality of concave parts 4 being formed by partially notching a sliding surface 5 on the scroll members, the concave parts 4 being arranged on at least one of a spiral inner peripheral surface 1b or a spiral outer peripheral surface 1a. Each of the concave parts 4 being open to the inner peripheral surface 1b or the outer peripheral surface 1a.

The disclosure relates to a conveyor device for at least conveying a fluid with at least one conveyor chamber, with at least one dimensionally stable conveyor chamber element that at least partially delimits the conveyor chamber and with at least one elastically deformable and, in particular, annular conveyor element, particularly a conveyor membrane, that delimits the conveyor chamber together with the conveyor chamber element and is arranged on the conveyor chamber element, wherein the conveyor element has at least one sealing extension that is designed integrally with a base body of the conveyor element and at least partially arranged in a sealing groove of the conveyor chamber element when the conveyor element is arranged on the conveyor chamber element.

A dry vacuum pump includes an elastic outer seal and at least one elastic inner seal respectively including a first and a second end annular parts parallel to one another and inserted between a respective end piece and the half-shells, and two side rails connecting the end annular parts and which are at right angles thereto, the side rails being inserted between the half-shells, the at least one inner seal being arranged inside the outer seal so that the at least one inner seal and the outer seal form at least two successive sealing barriers for the gases.

A scroll type gas machine that can suppress wear of tip seals is provided. The scroll type compressor includes: a fixed scroll 11 having a helical wrap 16; an orbiting scroll 12 having a helical wrap 21; a drive shaft 13 that causes the orbiting scroll 12 to orbit relative to the fixed scroll 11; and a helical tip seal 29A inserted into a seal groove 28A of the wrap 21. The tip seal 29A has: a groove 36A that has an opening at a central portion of a sliding surface 30 in the seal width direction; and a communication groove 37A that establishes communication between the inside of the groove 36A and a working chamber S.sub.H on the inner side in the wrap width direction. The groove 36A is provided in a range where the differential pressure (P.sub.H−P.sub.L) is equal to or higher than 0.1 Mpa between the working chamber S.sub.H on the inner side in the wrap width direction and a working chamber S.sub.L on the outer side in the wrap width direction. The communication groove 37A is shorter than the groove 36A in the seal extension direction.

A pump for supplying an assembly with a pressure fluid, the pump including: a pump housing including a circumferential wall, surrounding the pump's, a first end-face wall and a second end-face wall which delineate the delivery chamber at its end-face sides; a rotor, rotatable about an axis of rotation in the delivery chamber, for forming delivery cells; a pressure outlet which emerges on an outer end-face side of the first end-face wall facing away from the delivery chamber and through which pressure fluid can be discharged from the delivery chamber; an outlet gasket provided on the outer end-face side of the first end-face wall, for sealing off the pressure outlet; a holder in a holding engagement with the outlet gasket and which positions the circumferential wall and the end-face walls relative to each other and axially holds them together as a pre-fitted fitting unit by the holding engagement.

A compressor includes a shell, a first scroll member, a second scroll member and a sealing assembly. The shell defines a first pressure region and a second pressure region. The first scroll member is disposed within the shell and includes a first end plate and a first scroll wrap. The second scroll member includes a second end plate and a second scroll wrap. The second scroll wrap meshingly engages the first scroll wrap to define a compression chamber therebetween. The seal assembly fluidly separates the first and second pressure regions from each other. The seal assembly includes a first plate, a second plate, a sealing member. The sealing member is sealingly engaged with the first plate and the second plate.

A compressor includes an orbiting scroll, a cooling pipe and a crankshaft, the cooling pipe includes an inlet pipe and an outlet pipe, an axial through hole is provided at a center of the orbiting scroll, a sealing portion of the orbiting scroll is provided with a sealing groove, a mounting hole is provided in the crankshaft, the cooling pipe passes through the crankshaft and enters from a tail portion of the crankshaft, through the mounting hole, the axial through hole and the sealing groove, and then returns back on the same way, and a part of the cooling pipe is arranged in the sealing portion of the orbiting scroll, the cooling pipe moves synchronously with the orbiting scroll and rotates with respect to the crankshaft.