Abstract: A positive displacement rotary fluid pump assembly includes a pump housing and a rotor supported within the housing for rotation about an axis offset with respect to a housing axis and including a plurality of chambers of increasing volume on an low pressure side of the pump and of decreasing volume on a high pressure side of the pump. A fluid inlet communicates with the plurality of the chambers of increasing volume for admitting fluid into the pump under a first low pressure, and a fluid outlet communicates with a plurality of the chambers of decreasing volume for selectively expelling fluid from the pump under a second higher pressure. At least one fluid control valve is operative to selectively close one or more of the chambers of decreasing volume from communication with the fluid outlet when the fluid pressure in such chambers is below the predetermined value and to open one or more other chambers of decreasing volume when the fluid pressure in such chambers is at or above the predetermined value.

Abstract: Disclosed are a hydrostatic pressure support and a spherical pump having the same. The hydrostatic pressure support is arranged between each of two parallel sides of a slipper and a sliding groove, and includes a first liquid flow channel, a second liquid flow channel, and a pressure-bearing groove. An inlet of the first liquid flow channel is communicated with one of two working chambers of the spherical pump, and an inlet of the second liquid flow channel is communicated with the other of the two working chambers. An outlet of the first liquid flow channel and an outlet the second liquid flow channel are respectively communicated with the pressure-bearing grooves provided on the two parallel sides of the slipper.

Abstract: A screw compressor has a slide valve movement mechanism that includes a cylinder provided in a casing body, a piston partitioning an interior of the cylinder into a first chamber and a second chamber, and a communication flow passage through which the second chamber communicates with a low-pressure space. The cylinder includes a first inflow hole, a second inflow hole, and a third inflow hole. The first chamber communicates with a high-pressure space through the first inflow hole, the second chamber communicates with the low-pressure space through the second inflow hole and the communication flow passage, and the second chamber communicates with the high-pressure space through the third inflow hole. The third inflow hole is located at a position at which the third inflow hole is closed by the piston when the piston lies at a stop position at which the piston moves toward the second chamber and stops.

Abstract: A rotor for a mud motor includes a core having a first outer shape, and a shell positioned around the core, the shell having a second outer shape that is different from the first outer shape, the second outer shape defining one or more lobes and one or more cavities that are configured to engage a bore of a stator during rotation of the rotor relative to the stator. A thickness of the shell varies as proceeding around the core, from a non-zero minimum thickness to a maximum thickness.

Abstract: A rotary compressor may include an outflow passage through which refrigerant flows out of a compression space. The outflow passage may include at least one first outflow guide portion disposed in a main bearing or a sub bearing, at least one second outflow guide portion formed through between both axial ends of a roller, and at least one third outflow guide portion disposed in a bearing opposite to the bearing with the at least one first outflow guide portion based on the roller. This may minimize an amount of refrigerant remaining in the compression space. A pressure difference on a front of a vane may also be eliminated, which may suppress or prevent vane jumping. As the outflow passage is periodically opened, refrigerant leakage may be suppressed or prevented during a compression stroke.

Abstract: A scroll compressor may include an oil supply passage formed in a main frame. A first end of the oil supply passage may be open toward an orbiting space of the main frame and a second end may be open toward an Oldham ring. With this configuration, even if refrigerant suctioned through a refrigerant suction pipe sweeps away oil, which lubricates a sliding surface between a key and a key groove adjacent to the refrigerant suction pipe while passing through between the key and the key groove, oil may be quickly and smoothly supplied to the sliding surface. This may prevent wear between the key and the key groove so as to enhance efficiency of the compressor.

Abstract: A scroll assembly includes an orbiting scroll and a cross ring. The orbiting scroll is configured to have a bottom plate. A plurality of bayonets and two positioning slots are provided on the outer peripheral surface of the bottom plate. The bayonets are adapted to be clamped by a chuck of a turning tool. The cross ring is configured to have an annular body and two positioning pins. An annular groove adapted for being formed by turning is provided on the lower surface of the bottom plate of the orbiting scroll, and a chamfer is formed on the edge of the annular groove formed by the intersection of the circumferential vertical surface of the positioning groove and the lower surface of the bottom plate.

Abstract: A scroll compressor includes a discharge port formed at a central portion thereof, a pair of two compression chambers continuously moving toward the discharge port, and a plurality of bypass portions formed at each interval along a movement path of each compression chamber in the both compression chambers. Compression gradients of the both compression chambers are different from each other. An interval between a bypass portion closest to the discharge port and another bypass portion adjacent to the bypass portion among the bypass portions of each compression chamber is defined as a first interval. The first interval of a second bypass portion belonging to a compression chamber having a relatively larger compression gradient is smaller than the first interval of a first bypass portion belonging to the other compression chamber.

Abstract: An internal gear pump comprising: a ring with internal teeth delimiting a cavity and a gear disposed in the cavity, the gear comprising external teeth cooperating with the internal teeth to drive the ring in rotation, remarkable in that it comprises a pinion disposed in the cavity and driving the gear in rotation. The pinion cooperates with the external toothing of the gear. In an alternative embodiment, the gear comprises an internal toothing which cooperates with the pinion.

Abstract: A rotary pump, preferably a vane cell pump or a pendulum slider pump, includes a stator and a rotor which rotates about a rotational axis within the stator. The rotor includes multiple delivery elements which move radially in relation to the rotational axis, and two adjacent delivery elements limit a delivery cell together with the outer surface area of the rotor and the inner surface area of the stator. At least two delivery cells, preferably two adjacent delivery cells, exhibiting a first maximum cell volume form a first delivery cell group and at least two other delivery cells, preferably two other adjacent delivery cells, exhibiting a second maximum cell volume form a second delivery cell group. The first maximum cell volume of the delivery cells of the first delivery cell group is larger than the second maximum cell volume of the delivery cells of the second delivery cell group.

Abstract: A gear pump that selectively directs lubrication to certain components within the pump. A system and method of retrofitting existing pumps to improve their longevity in the field. The system and method provides a clean, simple, efficient, and elegant improvement to current gear pump fuel delivery systems.

Abstract: A variable displacement lubricant pump includes a housing, a control ring arranged in the housing, an inlet chamber and an outlet chamber, and a lateral slide bearing. The control ring is shiftable, radially confines a pumping chamber, and comprises a drainage channel. The outlet chamber and the inlet chamber are arranged at opposite lateral sides of the control ring. The lateral slide bearing is arranged at the lateral side of the control ring where the outlet chamber is arranged and comprises a first lateral slide bearing surface defined by the static housing, a second lateral slide bearing surface arranged opposite to the first lateral slide bearing surface which is defined by the control ring, and a lateral slide bearing gap defined between the first and second lateral slide bearing surfaces. The drainage channel of the control ring fluidically connects the lateral slide bearing gap with the inlet chamber.

Abstract: A scroll device is disclosed having a housing, a motor having a shaft, an orbiting scroll connected to the shaft for moving the orbiting scroll, a fixed scroll mated to the orbiting scroll, an idler shaft for aligning the orbiting scroll and the fixed scroll, an inlet formed in the housing and/or the fixed scroll for receiving a cooling liquid, and a channel formed in the idler shaft for receiving the cooling liquid.

Abstract: A scroll type positive displacement assembly includes a first scroll and a second scroll, where the second scroll is configured to orbit with respect to a center of the first scroll without rotating with respect to the first scroll. Together, the first scroll and the second scroll define a compression chamber between two seal points where the first scroll and the second scroll contact one another as the second scroll orbits with respect to the first scroll during a compression cycle, and the two seal points come together proximate to a discharge port between the first scroll and the second scroll such that there is at least substantially no dead space between the first scroll and the second scroll at an end of the compression cycle. For example, the two seal points remain in sealing contact during at least one hundred and eighty (180) degrees of the compression cycle.

Abstract: An oil-free water-injected screw air compressor comprises a housing that encloses two rotors for generating compressed air, and an air water separator for separating the water from the compressed air. Water injection can effectively cool a compressor, and some embodiments provide a sealing system for isolation of compressor bearing lubricant from water used for cooling.

Abstract: An example assembly comprises: a pump cover; a thrust plate configured to interface with the pump cover at a first side of the thrust plate and interface with gears of a gear pump at a second side of the thrust plate; and a seal disposed within a seal cavity formed at an interface between the thrust plate and the pump cover, wherein the seal defines multiple partitions at the interface between the thrust plate and the pump cover and seals each partition of the multiple partitions from other partitions.

Abstract: A rotary vane pump including a housing, and a motor. The motor includes a shaft which is coupled to a rotor. The rotor defines a plurality of slots. A plurality of free moving vanes are disposed within the slots. In one example, the rotor is formed from a first material and the plurality of vanes are formed from the first material and impregnated with a second material. The first material can be a carbon material. The second material can be a resin material, an antimony material, a copper material, or a silver material.

Abstract: A vacuum booster assembly includes, but is not limited to, a booster housing defining a booster chamber and including a gas inlet and a gas outlet; a first rotor positioned within the booster chamber and adapted for rotation therein, the first rotor including a first shaft and at least two lobes defining a first lobe profile; and a second rotor positioned within the booster chamber and adapted for rotation therein, the second rotor including a second shaft and at least two lobes defining a second lobe profile, wherein the first and second rotors are formed from a metal having a coefficient of thermal expansion from about 1 (10?6 in/in*K) to about 13 (10?6 in/in*K), and wherein at least one of the outer surface of the first rotor, the outer surface of the second rotor, or the booster chamber includes a coating.

Abstract: A variable hydraulic pump include a rotor mounted on a pump housing of which a housing spring end is formed, a pivot pin, an outer ring rotatably coupled to the pivot pin and of which a ring spring end is formed, a spring mounted between the housing spring end and the ring spring end, a pressure chamber formed in the pump housing to push the outer ring, a plurality of vane provided to form a plurality of pockets, an input port to supply oil to the plurality of pockets and a discharge port to exhaust oil supplied to the plurality of pockets, wherein at the reference position of the outer ring, the angle between a first imaginary line connecting the center of the rotor and the pivot pin and a second imaginary line connecting the ring spring end and the pivot pin is 0 to 10 degrees.

Abstract: A sealing arrangement between a rotating plane surface on a rotor and a machine housing prevents flow of process fluid between an internal volume and an external volume of the machine housing. The sealing arrangement includes a piston arrangement, and a sealing bearing ring between the piston arrangement and the rotating plane surface. A fluid supply line supplies pressurized lubrication fluid through the machine housing to a piston cavity, wherein the piston arrangement further includes piston fluid channels and the bearing sealing ring includes lubrication conduits through the bearing sealing ring, corresponding with the piston fluid channels. The pressurized lubrication fluid is arranged for moving the piston arrangement against the sealing bearing ring and thus moving the sealing bearing ring against the sealing surface thus forming a sealing arrangement.