Abstract: A piston limiting structure, including: a cylinder, a piston, and a flange provided with a limiting piece, the cylinder has a piston hole perpendicular to an axial direction of the cylinder and penetrating through the cylinder, and a projection of the piston hole in a penetrating direction is circular. The piston is disposed in the piston hole in a form-fit manner and is slid in the piston hole in a reciprocating manner. A side wall of the piston is provided with a thrust groove, a bottom surface of the thrust groove forms a thrust surface on the side wall of the piston, and the thrust groove does not penetrate through two ends of the side wall of the piston along an axial length of the piston. The limiting piece abuts against the thrust surface.

Abstract: A flow guiding device for use on a fan assembly with a motor-operated radial impeller rotating about an axis of rotation. The guiding device has an outer housing and an inner diffuser. A flow duct is formed between the outer housing and inner diffuser. The flow duct extends along an axial flow direction. The outer housing forms a receiving space for the integral holding of the radial impeller. The impeller borders, in the axial direction, on the inner diffuser. The impeller, during operation, takes in a flow axially and blows it out radially into the flow duct. The flow duct is adapted to deflect the flow from a radial direction into an axial direction.

Abstract: A refrigerant compressor assembly (20A, 20B, 20C) includes an axial compressor (22B, 22C, 22) that includes at least one axial stage. A downstream compressor (24) is located fluidly downstream of the axial compressor (22B, 22C, 22) and includes one of a mixed-flow impeller (46) or a centrifugal impeller (96). At least one motor (26, 27) is in driving engagement with at least one of the axial compressor (22B, 22C, 22) and the downstream compressor (24).

Abstract: A control device of a piston pump unit comprising at least two piston-cylinder units that operate in a phase-shifted manner for the purpose of liquid chromatography and to a piston pump unit is described. The control device corrects fluctuations of the system pressure while switching from one piston cylinder unit to the respective other piston cylinder unit. The fluctuations can occur as a result of the cooling of the liquid medium that is heated in an adiabatic manner during a pre-compression phase in the working piston. The control unit controls the piston speed of at least one piston-cylinder unit during the transition phase depending on at least one characteristic, which is ascertained from chronologically previously detected pressure values, such that variations of the system pressure as a result of the cooling of the adiabatically heated medium are at least partially compensated for.

Abstract: A hydraulic pump includes a work port, a high-flow piston, multiple high-pressure pistons, and an unloading valve. The work port couples to a fluid supply line of a hydraulic tool. The high-flow piston supplies fluid along a first flow path to the work port. The high-pressure pistons supply fluid along a second flow path to the work port. The unloading valve is fluidly coupled to the first flow path and the second flow path, and actuatable between an open state and a closed state. The unloading valve is configured to (i) permit fluid to flow from the high-flow piston to the work port in the open state, (ii) inhibit fluid from flowing from the high-flow piston to the work port in the closed state, and (iii) actuate from the open state to the closed state when a pressure of the fluid in the second flow path exceeds a threshold pressure.

Abstract: A wearable cooling device that is designed to rapidly restore and/or maintain a user's thermal comfort is provided. The disclosed wearable cooling device is versatile and may be affixed to or in contact with (or close proximity to) a variety of locations on a user's body, e.g., wrist, neck and ankle, among others. The wearable cooling device utilizes a forced air device, e.g., a fan, that blows air onto a wetted piece of media, e.g., fabric, which is in direct contact with a high thermally conductive element, e.g., copper or aluminum. The high thermally conductive element may be in contact with a user's skin or with a user's outer clothing. The wetted media is situated between the forced air device and the high thermally conductive element. When the forced air device is activated, the exhaust air passes onto and around the wetted media, which in turn cools the high thermally conductive element. As a result, the high thermally conductive element cools down the user.

Abstract: A fan device used with respect to a computing device. The fan device includes at least two fans that provide airflow for the computing device and a controller that adjusts the fans' speeds in an attempt to avoid harmonic vibrations of the at least two fans. The fan device may include at least one sensor, and the controller may adjust the fans' speeds based at least on information from the sensor(s) in the attempt to avoid the harmonic vibrations. The attempt to avoid the harmonic vibrations may also attempt to mitigate one or more of turbulence, pressure, over-heating, power consumption, or noise in, by, or around the computing device. Reversal of airflow may also be used. A fan bar that enables isolation of ground return noise may also be used. The controller may use sums of primes calculations, phase analysis, common divisor calculations, and the like. Also, associated methods.

Abstract: A method serves for operating an electronically controlled pump assembly (1), with which setting parameters of the pump (2) can be adjusted in an electronic control (6), for adaptation to the hydraulic demands of the location installation situation (4, 5). Operating data is registered during the operation of the pump assembly (1). After a predefined time and on the basis of the registered operating data, it is examined as to whether the pump assembly (1) has been set vis-à-vis the factory settings. If this is not the case a signal (11) is issued in order to point out the necessary setting.

Abstract: A lobe pump is provided. The lobe pump may include a housing having an inlet and an outlet for a medium to be pumped, at least one lobe mounted in the housing so as to be drivable and rotatable and which has at least two conveying vanes, and at least one sealing element per lobe mounted on a sealing body. The at least one sealing element runs over a contour of the at least one lobe during rotation of the at least one lobe and performs an outward travel movement from a minimum diameter of the at least one lobe to a maximum diameter of the at least one lobe and an inward travel movement from the maximum diameter of the at least one lobe to the minimum diameter of the at least one lobe on different sides of each of the at least two conveying vanes.

Abstract: A fluid routing plug for use with a fluid end section. The fluid end section being one of a plurality of fluid end sections making up a fluid end side of a high pressure pump. The fluid routing plug is installed within a horizontal bore formed in a fluid end section and is configured to route fluid between an intake and discharge bore. The fluid routing plug comprises a plurality of first and second fluid passages. The first and second passages do not intersect and are offset from one another. The first fluid passages are configured to direct fluid delivered to the horizontal bore from intake bores towards a reciprocating plunger. The second fluid passages are configured to direct fluid pressurized by the plunger towards a discharge bore.

Abstract: A jet pump comprising a jet nozzle for accelerating a propellant. The jet nozzle has a convergent inlet part and an outlet part connected to the convergent inlet part. The outlet comprises an inner wall diverging at an opening angle. The opening angle is designed such that a propellant flowing through the outlet part at subsonic speed is detached from the inner wall and a propellant flowing through the outlet part at supersonic speed is guided by the inner wall. An automatic, cost-effective and simple changeover of the jet pump to different pressure ratios is hence provided.

Abstract: A heat-activated multiphase fluid-operated pump. A hot chamber receptive of externally applied heat converts a working fluid into vapor. A pressure-control valve allows vaporized working fluid to escape the hot chamber only when a target pressure is exceeded. A liquid-piston chamber receives the vaporized working fluid, which expands adiabatically to displace pumped liquid within the liquid-piston chamber in a pump stage, expelling it through an exit port having a unidirectional check valve. A condenser receives the displaced liquid and allowing it in a suction stage to return to the liquid-piston chamber through another unidirectional check valve. An injector valve coupled between the liquid-piston chamber and the hot chamber facilitates jets of condensed working fluid to replenish the hot chamber in successive brief spurts responsive to periodic pressure pulses in the liquid-piston chamber that temporarily exceed the pressure in the hot chamber.

Abstract: A vacuum pump which can prevent lowering of an exhaust performance of the vacuum pump, even if a linked-type thread groove spacer is fastened by a fixing bolt, is provided. The linked-type thread groove spacer according to an embodiment of the present invention includes a structure for linking a Siegbahn pump portion and a thread-groove pump portion. When this linked-type thread groove spacer is to be fastened, a countersunk hole is provided in advance in an exhaust channel portion, and the linked-type thread groove spacer is fastened to a base by a fixing bolt. As a result, a head part of the fixing bolt does not protrude to the exhaust channel, and the head part of the fixing bolt does not make resistance against an exhaust gas. Thus, lowering of the exhaust performance of the vacuum pump can be suppressed.

Abstract: A nano gas pump for generating gas flow, gas compression and gas rarefication which provides up to several orders of magnitude pressure difference, operates over a wide range of pressure from several millitorr to several atmospheres, and with pumping speeds from several nano liters to several liters per minute. The nano gas pump does not require any moving parts and generate gas flow using steep temperature gradients of more than 100 milli Kelvin over a mean free path of the local gas in the direction of the gas flow. Temperature gradients are created and restricted mostly to the gas doing the work, through an arrangement of PNP, NPN, PP, NN thermoelectric segments together with conductive interconnects. Contact resistance which drastically reduces the efficiency of a nanoscale thermoelectric heat pump is mitigated by overlapping thermoelectric segments and electric connections.

Abstract: A pump fluid end having a reciprocating element a discharge valve assembly, a suction valve assembly, and a suction valve stop. The reciprocating element is disposed at least partially within a reciprocating element bore of the pump fluid end. The suction valve assembly is coupled with a front end of the reciprocating element. The suction valve stop is positioned within the reciprocating element bore such that the suction valve stop contacts and applies a closing force to the suction valve assembly when the suction valve assembly is stuck open at the end of a discharge stroke of the reciprocating element.

Abstract: A mounting hub operable to connect a flexible impeller to a drive shaft. The mounting hub is detachable from the impeller, and is adapted to permit the impeller to be decoupled rotationally from the impeller drive shaft during installation, and then recoupled rotationally once the flexible impeller is in position.

Abstract: A vacuum pump comprises: a rotor cylindrical portion; a motor configured to rotate the rotor cylindrical portion; a stator cylindrical portion, the rotor cylindrical portion and the stator cylindrical portion together forming a screw groove pump; a base housing the rotor cylindrical portion and the stator cylindrical portion; a heater configured to heat the base or the stator cylindrical portion; a cooling device attached to the base; and a cover member arranged at an outer peripheral side of the stator cylindrical portion and an outer peripheral side of the base, covering the base through an air insulating layer, and contacting the cooling device.

Abstract: A seal assembly configured for use with a high pressure single screw compressor includes a seal body and at least one attachment structure. The at least one attachment structure fixedly attaches the seal body to the rotor of the compressor, such that the seal body is rotatable along with the rotor. The seal body has a textured outer surface which creates a labyrinthine path between the compressor housing and the seal body.

Abstract: A fluid routing plug for use with a fluid end section. The fluid end section being one of a plurality of fluid end sections making up a fluid end side of a high pressure pump. The fluid routing plug is installed within a horizontal bore formed in a fluid end section and is configured to route fluid throughout the fluid end section.

Abstract: A liquid feed pump which increases the liquid flow velocity in a stagnation area in the pressure chamber of a plunger pump, thereby improving the liquid replacement speed in the plunger pump. When the liquid in the liquid feed pump is replaced, a first plunger slides back and forth in the space between a lower limit point and an upper limit point, and the second plunger stops at least temporarily at a position near to the upper limit point or slides back and forth for a shorter distance than when the liquid feed pump usually feeds the liquid.