An internal gear pump includes: an internal gear rotatably fitted in a body; an external gear inscribed in and meshed with the internal gear; a filler piece that partitions a liquid feeding space formed between the internal gear and the external gear into a high pressure region and a low pressure region; and a sealing member that covers both end surfaces of both the gears in a rotation axis direction and seals the liquid feeding space, in which a communication groove for communicating an enclosed space surrounded by the filler piece and a tooth groove of at least one of the gears with the high pressure region is formed, and the communication groove is formed such that a cross-sectional area communicating with the enclosed space continuously increases and an increase rate thereof acceleratively increases as a rotation phase of both the gears advances.

A gerotor pump for conveying a fluid from an inlet pump chamber which is connected to an inlet to an outlet pump chamber, which is connected to an outlet, of the gerotor pump having a rotatable outer rotor; a rotatable inner rotor, which is arranged radially inside the outer rotor; a housing having a housing cover and a housing base, between which the outer rotor and the inner rotor are arranged; and at least one compensation plate which is arranged in each case axially between the outer rotor and inner rotor and the housing cover or the housing base, wherein the at least one compensation plate in the idle state of the gerotor pump is axially spaced apart from the outer rotor and the inner rotor by pretensioning.

Improved bushing assembly (10) for supporting the shafts of the intermeshed rotors of a positive displacement rotary pump avoiding jamming, said bushing assembly (10) comprising on a lateral surface (13) thereof at least one compensation tank (15; 16) facing a suction side of the pump and at least one bleed channel (14) which connects said compensation tank (15; 16) to the discharge side. [FIG. 7]

A gear pump includes a pair of gears that meshes with each other, two rotational shafts inserted into the respective gears that rotate together with gears, a pair of side plates arranged adjacent to both side surfaces of the gears, each having two through-holes forming bearings of the two shafts, a seal block that abuts against the pair of side plates and covers a part of the pair of gears, a pump assembly having the gears, the two shafts, the pair of side plates, and the seal block, and a case having a recess to accommodate the pump assembly. A line passing through an arc center of a cylindrical surface inscribed in the facing surface of the case, and parallel to the two shafts, forms a rotating axis. When the pump assembly rotates about the rotating axis, one of the of side plates contacts the inner wall of the case.

A fluid pump includes a housing defining a cavity. An end plate is disposed within the cavity and divides the cavity into a gear section and an end section. A gear set is disposed within the gear section and comprises at least one gear rotatable about an axis. The end plate is movable longitudinally along the axis for compressing the gear set. A channel is in fluidic communication with the end section for supplying a fluid to the end section to force the plate toward the gear set.

The disclosure concerns a Roots-type blower comprising a housing defining first and second transversely overlapping cylindrical chambers and at least one inlet port and an outlet port; first and second meshed, lobed rotors, each lobe having a top land sealingly cooperating with the cylindrical chambers; a plurality of control volumes for transfer of fluid, each control volume being defined by a pair of adjacent lobes on one of the rotors, and at least one of the cylindrical chambers; and blowholes formed within the cylindrical chambers in connection with meshing of the lobes of the first and second rotors. The blower further comprises at least one backflow slot extending through the housing wall of each cylindrical chamber for effecting a leakage of fluid from downstream the at least one outlet port into a control volume.

An internal gear pump, in particular a hydraulic pump for a slip-controlled vehicle braking system, is configured to be pre-assembled. The internal gear pump includes a cartridge configured as a casing, which is configured to be inserted in a receptacle in a hydraulic block of a vehicle braking system.

A multistage gear pump assembly includes first and second gear pumps that use common shafts and are axially separated by a fixed spacer within the housing. Pressurized bearings are provided at opposite axial ends of the first and second gear pumps. The second gear pump handles cruise and idle operations of the aircraft while the first gear pump stage assists in meeting higher demand modes of engine operation. Otherwise, the first gear pump is maintained at a minimal pressure to reduce energy consumption and still provide desired stability and eliminate issues associated with bearing oil whirl associated with prior known arrangements. When additional assistance is required, such as during takeoff, climb, or windmill relight, the first gear pump advantageously contributes to the increased pressure.

A method and a device for fixing and synchronizing rotary pistons in a rotary piston pump involves introducing the rotary pistons into the pump space of the rotary piston pump. A shaft stub of each rotary piston is then pushed through a pump rear wall onto a driveshaft provided for the respective rotary piston. The rotary pistons are aligned and synchronized in the pump space via a template, the template being fixed detachably to a pump housing. The shaft stubs of the respective rotary piston are connected, after the synchronization, in each case via a clamping device in a friction-locked manner to the respective driveshaft, outside the pump space.

The purpose of the present invention is to suppress the occurrence of unevenness in a rotor of an internal gear pump, suppress the formation of gaps between the end surfaces (side surfaces) of an inner rotor and an outer rotor, and to prevent a decline in volume efficiency. Thus, the pump device of the present invention includes an internal gear pump (10), in which an inner rotor (13) is inscribed to an outer rotor (12), and includes a plate member (7) which is provided to an end surface of the rotors. The plate member (7) is formed of a material having high hardness, has a shape that does not block a suction port (150), has a through-hole (73) formed therein, and has O-ring grooves (71,72), which each have a continuous shape and house an O-ring formed therein.