A geared positive-displacement machine (10), comprising a housing (11) provided with a suction port and with a discharge port, a pair of gearwheels (14, 15) that are housed and supported by respective shafts (16, 18) for the rotation in a space inside the housing (11) and in fluid communication with the suction port and the discharge port, wherein the gearwheels (14, 15) mesh with each other and have parallel or coinciding axes and a first wheel (14) thereof is driving and a second wheel (15) is driven, a pair of containment bodies (19, 20) for axially containing the wheels (14, 15), said containment bodies (19, 20) being associated with the housing (11) and each comprise a first face (19a, 20a) that faces the pair of gearwheels (14, 15) and a second face (19b, 20b) that is axially opposite with respect to the first face (19a, 20a), and, for each of the two wheels (14, 15), a plurality of rolling bodies (21) that form a crown and that are freely housed in an annular seat (22) that is coaxial to the respective shaft (16, 18) and that is defined at the interface between the first face (19a, 20a) of at least one of the two containment bodies (19, 20) and the surface (14a, 15a; 14b, 15b) of the wheels (14, 15) that in turn faces it, respectively in the first face (19a, 20a) of at least one of the two containment bodies or in the surface (14a, 15a; 14b, 15b) of the gearwheels facing the first face (19a, 20a), wherein the rolling bodies (21) rest on rolling tracks (23, 24) respectively integral with the wheels (14, 15) and with the at least one containment body (19, 20). Between the first face (19a, 20a) of the at least one containment body (19, 20) and the surface (14a, 15a; 14b, 15b) of the wheels (14, 15) facing the first face a distance (D) greater than zero exists.

A self adjusting gear pump (10) for an ice cream freezer and a control unit (20) for adaptively controlling the closing pressure (PCLOSE) of a pump for an ice cream freezer. The gear pump system comprises a pump casing (11), an inlet (12) for receiving a liquid food product of ice cream mix, an outlet (15) for transferring the ice cream mix into a freezing cylinder (41) of the ice cream freezer (40), wherein the pump (10) is closed by supplying a closing air pressure onto a moveable pump cover (16) of the pump via at least one hole (191, 192) provided straight through the pump casing (11), thereby moving said moveable pump cover (16) against the star wheel (14) and a control unit (20) for supplying a calculated closing air pressure (PCLOSE) to the pump by means of the air pressure regulator (100).

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 sealant application includes an interface structure having an interface for interfacing with a source of sealant and a nozzle structure including a nozzle for dispensing sealant. A gear pump module including a gear pump is configured to be detachably connectable to each of the interface structure and the nozzle structure such that sealant provided at the interface is pumpable by the gear pump from the interface to the nozzle.

A rotary positive displacement pump includes a main body rotationally supporting two parallel, axially extending, shafts with gears in constant mesh condition, such that the shafts rotate in opposite directions. A rotor case body is connected to a front side of the main body and has a stationary interior pumping cavity, fluid product inlet and outlet openings, and two cylindrical rotor case hubs each receiving internally one of the shafts. A pair of rotors each have a rotor wing and a rotor drive element that is mounted torque proof on a rotor seat at an end region of one of the shafts. Each rotor seat pair has an axial abutment surface and a mounting surface. The pump also includes fasteners each engaging a mating section of one of the shafts and exerting an axial clamping force on one of the rotor drive elements against one of the axial abutment surfaces.

Methods and apparatus pertaining to positive displacement pumps, and further to hydraulic actuation systems. In some embodiments the pumps are gear pumps with bi-directional operation. In some embodiments the actuation system includes a motor-driven, reversible operation gear pump providing fluid under pressure to a rod and cylinder.

Overheating of a process liquid retained in a reservoir of a multiphase pump during extended gas slugs is avoided by circulating a cooling liquid in thermal contact with a process liquid through an external cooling apparatus, which can include a heat exchanger. In some embodiments, process liquid from the reservoir is circulated through the cooling loop, while in other embodiments a separate cooling liquid is circulated between a reservoir heat exchanger and the external cooling apparatus. The liquid in the cooling loop can be circulated by a separate cooling pump, or process liquid can be circulated through the cooling loop due to a pressure differential between an inlet and an outlet of the cooling loop within the multiphase pump. The multiphase pump can be a twin screw pump, and the reservoir can be formed between outer and inner casings of the multiphase pump.

A pump for an engine includes a suction chamber, a discharge chamber, and a piston at least partly received within a relief chamber. The piston has first and second passageways provided therein. The second passageway is located closer to a face of the piston than the first passageway. The piston is movable within the relief chamber, so that the volume of the fluid transfer from the suction chamber to the discharge chamber is varied according to a pressure in the relief chamber. The first and second passageways form fluid paths between the suction chamber and the discharge chamber at a first and second pressure in the relief chamber, respectively, the first pressure being less than the second pressure.

A pump bearing member is disclosed for use in a pump bearing assembly and a gear pump assembly.

A liquid pump includes a pump assembly attached to a motor. The pump assembly includes an inlet chamber and pump chamber. The pump chamber accommodates a drive gear driven by an output shaft of the motor and driven gear meshed with the drive gear. An inner cover is disposed within the pump chamber. An outer cover overlies the inner cover with an elastic member disposed there between. The outer cover exerts a force to the inner cover through the elastic member and holds the inner cover in sliding contact with an axial end of the drive and driven gears. An outlet chamber formed between the inner cover and the outer cover is in fluid communication with and the pump chamber.