An inner wall surface of a pump housing has a slide surface, which is opposite from a joint member and along which an inner rotor is slidable. This slide surface includes an external tooth slide surface and a main body slide surface. External teeth of the inner rotor are slidable along the external tooth slide surface, and a main body of the inner rotor is slidable along the main body slide surface. A surface roughness of the main body slide surface is higher than a surface roughness of the external tooth slide surface.

A gerotor pump includes a rotor wherein only on the face wall of the rotor that lies adjacent to a pressure kidney and a suction kidney, a lubrication surface inclined in the direction of rotation of the rotor, relative to the surface plane of the face wall of the rotor, is disposed on each tooth, in each instance, over its tooth height, either starting directly in the center tooth plane or starting “offset” ahead of the center tooth plane in the direction of rotation of the rotor, which surface is formed from a level surface or multiple, always level partial surfaces that follow one another, which enclose an angle of inclination relative to the surface plane of the face wall of the rotor, in each instance, which angle lies in the range from 0.2° to 7°, in each instance.

The present invention comprises: a stator 2 that is cylindrical and has a through hole 10, the through hole 10 in the shape of a female screw and being formed at a certain pitch in the flow direction from an inlet to an outlet; and a rotor 3 that is formed in the shape of a male screw, is inserted into the through hole 10 of the stator 2 to form a transport space 11 with the inner circumferential surface of the through hole, and rotates to move a fluid from the inlet to the outlet through the transport space 11 while being inscribed on the inner circumferential surface. The volume of the transport space 11 is reduced toward the flow direction. This prevents, reliably, the occurrence of bubbles from a fluid at a downstream-side when the fluid is transported through the transport space 11 formed between the stator 2 and the rotor 3.

Method for delivering a gas/liquid mixture fluid via a screw spindle pump that has a housing in which a drive spindle and a running spindle are accommodated. The spindles delimit together with the housing multiple pump chambers. A respective one of the pump chambers that is initially open toward the respective fluid inlet is closed off. The resulting closed-off pump chamber is moved axially toward the fluid outlet and, there, upon attainment of an opening rotation angle, is opened toward the fluid outlet. The drive spindle is driven so that the pressure in the respective pump chamber prior to and/or upon attainment of the opening rotation angle is increased in relation to the suction pressure of the screw spindle pump by at most 20% or by at most 10% of a difference in pressure between the suction pressure and the pressure in the region of the fluid outlet.

An engine fuel control system includes a main pump which receives fuel from a low pressure source and delivers the fuel at a first high pressure, and a variable displacement augmenter pump which receives fuel from the low pressure source and delivers the fuel at a second high pressure. The augmenter pump has a servo-controller to vary its pump flow rate. The system includes an augmentation valve which is actuatable by an electrically operated control valve to open a flow path therethrough which diverts fuel delivered by the augmenter pump or to shut the flow path. The system includes a pressure drop control valve which senses a pressure differential between the second high pressure and a reference pressure, and controls the servo-controller to vary the pump flow rate of the augmenter pump. The pressure drop control valve spills some of the fuel delivered by the augmenter pump.

There are already known pump units comprising a drive shaft (2) and a rotatably arranged rotor (3) that is driven by the drive shaft (2), wherein the drive shaft (2) has an inclined sliding surface (4) on an end side, which permits the rotor (3) to move back and forth by its rotor axis (5) about a drive axis (6) of the drive shaft (2), wherein the drive shaft (2) has a first bearing section (18) facing towards the the rotor (3), and a second bearing section (19) facing away from the rotor (3). The first bearing section (18) of the drive shaft (2) is arranged in a first sliding bearing (20), and the second bearing section (19) is arranged in a second sliding bearing (21). The load-bearing capacity of the sliding bearing facing towards the rotor (3) is limited up to a predetermined working pressure in the pump unit. In the pump unit according to the invention, the load-bearing capacity of the sliding bearing (20) facing towards the rotor (3) is increased. According to the invention, the diameter of the first bearing section (18) of the drive shaft (2) and the first sliding bearing (20) is respectively larger than the diameter of the second bearing section (19) and the second sliding bearing (21).

Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

A fuel system for a turbomachine includes a fuel tank and a first fuel line in fluid communication with the fuel tank and one or more fuel injectors. The first fuel line includes a main fuel pump disposed on the first fuel line, and an electric metering system disposed on the first fuel line downstream of the main fuel pump configured for starting the turbomachine and metering fuel to the fuel injectors.

A fuel system includes a fuel gathering system in fluid communication with a fuel storage container, and a fluid pump assembly in fluid communication with the fuel gathering system. The fluid pump assembly includes a main gear pump stage and a first flow attenuator. A main driven gear is meshed with a main drive gear in a main pump conduit, and a main pump bearing assembly rotatably supports the main drive gear and the main driven gear. The first flow attenuator is disposed around the main pump conduit, and includes a substantially polygonal fluid opening. Edges of the opening are substantially aligned with an undercut bearing portion on at least one of an inlet side and an outlet side of the main pump conduit to define a non-round fluid boundary.

An apparatus for reducing noise of a gear pump through uneven pitch-simulated control includes a calculation unit to calculate different control current values for each tooth of a teeth order by applying a teeth number, the teeth order, and a teeth angle of the gear pump in which a plurality of teeth are evenly formed, a storage unit to map and store the teeth order and the different control current values corresponding to the teeth order for each tooth, and a current controller to variably generate the control current value mapped corresponding to the teeth order when each tooth reaches a reference position when the gear pump rotates by a motor, wherein the control current value is added to a reference current value of a motor control signal and applied to the motor.