An internal gear pump includes a pinion, a ring arranged around the pinion, and a cylindrical wall arranged around the ring. A support element, on which the pinion and the ring are supported, carries high-pressure liquid towards a recess located at the junction between the ring and the cylindrical wall, and also carries low-pressure liquid towards another recess located at another point of the junction between the ring and the cylindrical wall. The recess allows the load of the ring on the cylindrical wall to be reduced.

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 groove is applied to one or more contact surfaces of a journal bearing of a pump to increase a force applied to the contact surface(s). Each groove has an end exposed to discharge pressure of the pump so that the groove communicates the discharge pressure across the contact surface. The groove reduces an area of the contact surface over which fluid leakage results in a pressure differential, thereby increasing a net force applied to the contact surface. Applying the groove to the axial end face of the journal bearing enhances an axial force applied to the journal bearing whereas applying the groove to a radially facing land reduces friction between the journal bearing and the outer housing.

A rotary pump including: a pump housing including a delivery chamber, having an inlet and an outlet for a fluid; a delivery member which can be rotated about a rotational axis in the delivery chamber in order to deliver the fluid; a setting structure which can be moved translationally back and forth in the pump housing relative to the delivery member in and counter to a setting direction in order to adjust the delivery volume of the rotary pump; a setting device for generating a setting force which acts on the setting structure in the setting direction; a restoring spring for exerting a restoring force which acts on the setting structure counter to the setting direction; and an additional spring for exerting an additional force which acts on the setting structure in or counter to the setting direction.

One embodiment of a modular pump includes a cover and a housing that may be engaged with one another during operation. A gearset may be positioned within an internal portion of the housing. If the modular pump is configured as a rotary pump, the gear set may be comprised of an inner gear positioned within a portion of a ring gear. The modular pump may include a spacer positioned between the cover and the housing to allow the modular pump to be configured with gear sets of varying axial dimensions.

One embodiment of a method for operating an internal combustion engine under a pressure less than atmospheric pressure includes the steps of positioning a vacuum pump such that said vacuum pump is in fluid communication with a crankcase of said internal combustion engine, connecting a discharge of said vacuum pump to a separator, wherein a portion of said discharge of said vacuum pump condenses in said separator, connecting a vapor discharge of said separator to a filter, wherein said filter removes a portion of volatile organic compounds from said vapor discharge, and venting said filter to an ambient atmosphere.

A low pressure gear pump and wear plate is disclosed. The wear plate may comprise a sidewall, a drive portion, a driven portion, and a transition portion. The sidewall is free of a sealing member or a recess configured to receive the sealing member. The drive portion includes a drive inlet lip, a drive outlet lip, a drive recessed trough and a drive bore. The drive bore is configured to receive the drive shaft of the gear pump. The driven portion may that include a driven inlet lip, a driven outlet lip, a driven recessed trough, and a driven bore. The driven bore is configured to receive the driven shaft of the gear pump. The transition portion may include a transition aperture configured to receive a first fastener configured to mount the wear plate to the gear housing. The wear plate is made of bronze, aluminum or non-magnetic material.

A gerotor pump is provided with a body defining a chamber with cylindrical wall sections and having a fluid inlet and a fluid outlet, and a cover. An internally toothed gear member is supported for rotation within the chamber about a first axis, and has a cylindrical outer wall defining a series of grooves. Each groove has an associated aperture extending through the gear member to an inner surface of the gear member, and is radially positioned between adjacent teeth of the internally toothed gear member. An externally toothed gear member is rotatably supported within the internally toothed gear member about a second axis spaced apart from the first axis, and is coupled for rotation with a drive shaft. The internally toothed gear member and externally toothed gear member cooperate to form a plurality of variable volume pumping chambers therebetween to pump fluid.

The bearing assembly, consisting of a stator component (S1) and a rotor component (R1), where the rotor component is adapted for a back-and-forth oscillatory movement (P, −P) relative to the stator component, whereby a number of cavities (301 and 302; 303 and 304) coordinated along the outer periphery of the rotor component and the inner periphery of the stator component, formed with an increasing volume (301 and 302) and a decreasing volume (303 and 304), respectively, during rotation of the rotor component in an initial direction (P) from an initial position (IP) and towards a final position (FP), while the cavities allow the volumes to decrease and increase during a rotational motion of the rotor component in a second direction (−P) in relation to the stator component (S1). The invention specifies that the above-mentioned bearing arrangement is to be adapted to interact with an instrument (M1) in order to determine, with the help of at least two components, the momentary position of the rotor component in relation to the stator component.

The invention relates to an eccentric screw pump, comprising at least one stator (1) composed of an elastic material and a rotor (2) that can be rotated in the stator (1), the stator (1) being surrounded by a stator casing (3) at least in some regions. The stator casing (3) consists of at least two casing segments (19) as a longitudinally divided casing and forms a stator clamping device, by means of which the stator (2) can be clamped against the rotor (1) in the radial direction. The pump is characterized in that the casing segments (19) have at least one clamping flange (20) having first clamping surfaces (21) at each end of the casing segments and that one or more clamping elements (22, 23), which can be displaced in the axial direction and have second clamping surfaces (24), are placed onto the clamping flange (20), the first clamping surfaces (21) and the second clamping surfaces (24) being designed in such a way and interacting in such a way that the stator casing (3) can be clamped against the stator in the radial direction in the course of an axial displacement of the clamping elements (22, 23).