Abstract: A multi-piece fluid end that can be produced with fewer raw materials and at a lower cost. In one embodiment, a fluid end is formed from a first body attached to a separate second body. Their respective external surfaces may be engaged flushly, partially, or via one or more spacer elements. In some embodiments, the body pieces are flangeless to reduce stress on the fluid end. The second body may have a plurality of bores that are alignable with a plurality of corresponding bores formed in the first body. The second body may be connected to a power end using a plurality of stay rods. In other implementations, more than two body pieces may be utilized.

Abstract: A flangeless fluid end comprising a fluid end body releasably attached to a connect plate. The connect plate is attached to a power source using stay rods. The flow bores of the fluid end are sealed without threading a retainer nut into the walls of each bore. Instead, the flow bores are sealed by bolting a retainer to the fluid end body. Plungers to drive fluid through the fluid end body are installed within removable stuffing box sleeves. These sleeves are maintained within the plunger bores by the bolted retainers. A number of features, including the location of seals within bore walls and carbide inserts within valve structures, aid in reducing or transferring wear.

Abstract: A cylinder head cover for a coolant compressor, wherein the cylinder head cover is attachable to a cylinder head arrangement in order to form a hollow space for receiving a coolant compressed by the piston, wherein the cylinder head arrangement comprises a valve plate attached to the cylinder housing and having an outlet opening and an outlet valve, which closes the outlet opening in cycles and consists of a valve spring and a stop plate for delimiting an opening movement of the valve spring. In order to achieve a cost-efficient production and installation of the cylinder head cover while assuring a secure support of the stop plate, it is provided that the cylinder head cover can comprise at least two contact surfaces for supporting stop plates of different outlet valves in order to adjust different opening positions of the valve springs of the different outlet valves.

Abstract: A fluid end assembly of a reciprocating pump has multiple fluid end bodies that are removably attached, independently of each other, to a power end assembly of the reciprocating pump, and to a manifold of the fluid end assembly. Each fluid end body defines a discharge outlet that is coaxial with a plunger bore for a reciprocating plunger, and a suction inlet that is disposed above the discharge outlet. A valve assembly is removably insertable into a valve port extending from an external surface of a manifold attached to the fluid end body, without having to remove the manifold from the fluid end body. The valve assembly includes a valve mechanism surrounded by a cylindrical valve body that lines the internal wall of the manifold defining the valve port, thereby forming a barrier between fluid flowing through the valve assembly and the internal wall.

Abstract: A pump comprises a housing (141) having a cavity (142) with an inlet valve (143), an apparatus (144) for raising fluid pressure in the cavity (142) and a discharge valve (145), the discharge valve (145) comprises a valve head (160) movable between an open and closed position and a valve seat (167), wherein the pump further comprises a booster piston (182) arranged in a booster cylinder (183), the booster piston (182) has a first face (191) exposed to a low pressure zone (189) and a second face (194) exposed to fluid pressure in the cavity (142), and at least one of the booster piston (182) and the booster cylinder (183) is movable relative to the other to add an opening force to the discharge valve. The pump is preferably a mud pump for circulating drilling mud through a drill string in a wellbore or a cement pump which may be of the type for pumping cement into a wellbore.

Abstract: A bed rail for engagement between a mattress and a box spring and having a base support and a guard frame, with guard frame having a pivot that pivots and slides in the base support. The base support includes a first seat that seats the pivot and a second seat that seats a biased piece sliding axially on a first support member of the guard frame. The first support member extends from a plastic piece that forms a junction from which a second support member and the pivot extend and that nestles up to the second seat.

Abstract: A sealed compressor comprises an electric element; a compression element; and a sealed container accommodating the electric element and the compression element; wherein the compression element includes a cylinder block defining a compression chamber; a piston which is reciprocatable inside the compression chamber; and a valve plate disposed to close an opening end of the compression chamber and having a discharge hole which provides communication between inside and outside of the compression chamber; the piston has a first groove on a tip end surface thereof which faces the valve plate, the first groove having a predetermined width and extending from an outer peripheral edge portion of the tip end surface toward a portion of the tip end surface which faces the discharge hole; and a tip end portion of the first groove is positioned in the portion of the tip end surface which faces the discharge hole and is inclined.

Abstract: A reciprocating compressor including a casing which has first and second cylinders, an electric motor which has a drive shaft mounted in the casing, first and second pistons fittingly inserted into the first and second cylinders respectively, so as to reciprocate therein, and first and second connecting rods attached to the first and second pistons, respectively, at ends thereof and which are situated in the crank chamber at the other ends thereof where first and second bearings are provided, respectively. A crank member is provided on the drive shaft within the crank chamber, and the crank member is fittingly inserted into the first bearing of the first connecting rod and the second bearing of the second connecting rod. The crank member has a positioning member which positions the first and second bearings with respect to an axial direction.

Abstract: A plunger pump fluid end housing in which the access, suction, and discharge bores within each fluid chamber are offset from the plunger bores. The plunger bore centerline being fixed by the spacing in the pump power end section. The access, suction, and discharge bores in the outside fluid chambers of the pump are offset toward the center of the fluid end. The direction of the offset of the outside fluid chambers opposes the direction of offset of the opposite outside fluid chambers. A special access bore plug with asymmetrical integral spacers is also disclosed.

Abstract: A compressor that allows a discharge port to assume a large circumference and a large area at an exit end thereof so as to optimize the discharge resistance and the pressure-receiving area and assuring improved volumetric efficiency through reduced dead volume, includes a discharge port 5b, an entrance end of which opens into a compression chamber and an exit end that is able to open and shut with a discharge valve 43. The discharge port 5b is constituted with a recessed portion 50 formed to achieve a predetermined depth from the exit end and a through portion 51 having a smaller sectional area than the sectional area of the recessed portion 50. The through portion 51 is formed so that its width measured along a direction perpendicular to the longitudinal direction of the discharge valve is greater than its width measured along the longitudinal direction of the discharge valve 43.

Abstract: An automatic depressurizing pump includes an air-generating unit and an airflow control unit. The air-generating unit has a first air intake hole. An air generated by the air-generating unit drives the air control unit so as to inhale or exhale airflows through the first air intake hole. The airflow control unit includes a valve base, a first valve, a second valve, a top cover, and a resilient member.

Abstract: A pump having an endplate with an orifice provided between the system ports and the charge pump pressure cavity. Fluid flows through the orifice so as to soften a transition of the vehicle from a stationary position to a forward or reverse motion when a swash plate of the pump is angled slightly relative to a neutral or zero position.

Abstract: A novel valve assembly is provided. In one embodiment, the valve assembly includes a seat plate having a plurality of fluid conduits. The valve assembly may also include a plurality of poppet assemblies. In some embodiments, a poppet assembly of such a plurality includes at least one fluid port and a housing configured to be coupled to the seat plate to facilitate flow of a fluid through a respective fluid conduit via the at least one fluid port of the respective poppet assembly. Other devices, systems, and methods related to poppet assemblies are also disclosed.

Abstract: In accordance with various embodiments of the present invention, a system and method are provided for converting a conventional automobile engine into a gas compressor. In various embodiments, the system and method may provide an economical and efficient gas compressor by modification of a balance-opposed internal-combustion engine to provide a balance-opposed gas compressor. More specifically, in some embodiments, the modification may include a uniquely designed cylinder head adapted to convert an automobile engine into a gas compressor for the recovery, gathering, transfer, or staged compression of natural gas. In one embodiment, a four-cylinder balance-opposed engine is utilized.

Abstract: One describes a support for a proximity sensor to sense the proximity of a piston of a compressor, a compressor proper, a valve plate of a compressor and a cooler provided with these pieces of equipment. One of the objectives of the present invention is achieved by means of a support for a proximity sensor for sensing the proximity of a piston of a compressor comprising a cylinder for the piston, the cylinder being associated to a valve plate, configuring a high-pressure region inside the cylinder and a low-pressure region outside the cylinder, the support comprising a base structure, a first connection end portion and a second connection end portion, the proximity sensor being associated to the high-pressure and the base structure extending as far as the low-pressure region.

Abstract: A downhole pump has a barrel and a plunger. The barrel has a first one-way valve and the plunger has a second one-way valve. The plunger is of the box end type. The pump prevents or minimizes gas lock by achieving high compression in the compression chamber between the two valves. The second valve is located close to the bottom end of the plunger. In the second valve, the valve seat is in contact with the seat plug, which seat plug has a seal. Alternatively, the valve seat is incorporated into the seat plug, which seat plug also has a seal. The plunger lacks reliefs at the bottom end and thereby achieves tight tolerances with the barrel, further contributing to high compression.

Abstract: A novel valve assembly is provided. In one embodiment, the valve assembly includes a seat plate having a plurality of fluid conduits. The valve assembly may also include a plurality of poppet assemblies. In some embodiments, a poppet assembly of such a plurality includes at least one fluid port and a housing configured to be coupled to the seat plate to facilitate flow of a fluid through a respective fluid conduit via the at least one fluid port of the respective poppet assembly. Other devices, systems, and methods related to poppet assemblies are also disclosed.

Abstract: A double-diaphragm pump includes a pair of axially spaced apart pumping chambers, each chamber having a pumping diaphragm which divides each chamber into an inner and outer compartment. Inner ends of both pumping chambers are closed by a central element, and fluid is supplied to the outer compartments to cause the diaphragms to oscillate and vary the capacities of the inner compartments. I Each of the inner compartments having an inlet and an outlet port leading to unidirectional valves to allow fluid to be drawn into one of the compartments when the appropriate diaphragm moves outwardly and expelled from that compartment when the diaphragm moves inwardly. The unidirectional valves are located in inlet and outlet manifolds in the central element and are accessed and fitted through the inlet and outlet ports in the inner compartments.

Abstract: A valve plate includes a suction port to which gas to be compressed in a compression chamber flows in and a discharge port from which gas compressed in the compression chamber is discharged, a projection that appears from the discharge port with the reciprocating movement of the piston is arranged at a position facing the discharge port at a distal end face of the piston, and the projection includes a flat surface extending parallel to a reciprocating direction of the piston, so that a highly efficient hermetic type compressor that reduces the dead volume of the discharge port and reduces the loss in the compression chamber and the discharge port is provided.

Abstract: A coolant compressor (1), comprising a piston-cylinder unit (2) that compresses a coolant, said piston-cylinder unit comprising a cylinder housing (4) and a piston (3) held in a piston bore (5) of the cylinder housing (4), wherein the cylinder housing (4) is sealed in an axial direction by a valve plate (6) and a cylinder cover (7). In order to facilitate the simple and flexible mounting of the valve plate (6) at the cylinder housing (4), it is provided according to the invention that the valve plate (6) is countersunk in its operating position in the piston bore (5) of the cylinder housing (4) and is fastened in the piston bore (5) of the cylinder housing (4) by way of a material bond connection, so that an end stop provided especially for the valve plate (6) in the cylinder housing (4) can be omitted.

Abstract: High pressure plunger pump, comprising at least two in-line cylinders as seat for respective plungers, where each cylinder is connected via respective conduits and relative valves to an intake manifold and to a delivery manifold, the cylinders are provided within a single block together with the conduits and the manifold; the intake manifold is positioned in front of the line of cylinders and is in direct communication with the cylinders via a conduit connected to a dead compartment provided as an extension of the respective cylinder and in which the intake valve is located; the intake valve is retained in position by the actual valve seat sealing gaskets or by an elastic plate.

Abstract: Refrigerant compressor for a hermetically encapsulated small refrigerator, which has a piston (20) guided in a piston bore (3) of a cylinder housing (1), the cylinder housing being frontally terminated using a valve plate (7) having a pressure opening (17) and a suction opening (16) and also being frontally provided with holes (5), which each have a thread.

Abstract: A supply device for the supply of pressure fluid into at least one vehicle brake or into a pressure fluid accumulator, wherein a piston is movably arranged in an accommodating member, a carrier bears a non-return valve arranged coaxially to the piston for the purpose of ventilating a working chamber into which the piston plunges, and wherein a resetting spring is arranged between the carrier and the piston. A multi-piece cage facilitating inserting the resetting spring into the cage parts, the cage parts comprise a fastener that locks the cage due to relative displacement of the cage parts, and the resetting spring is caged and simultaneously elastically preloaded under the relative displacement of the cage parts.

Abstract: A piston valve for improving the output efficiency of a diaphragm pump includes a central discharge base and a plurality of water inlet ports, wherein each of the discharge base and water inlet ports is provided with a top concave surface, and a plastic gasket is engaged with the concave surface of the water discharge base and a piston slice is engaged with the concave surface of each water inlet port so that a gap is defined between the gasket and its concave surface and a gap is also defined between each piston slice and its corresponding concave surface.

Abstract: A pressure enclosure includes a first component having an opening, a second component coupled to the first component in a position over the opening, a third component positioned between the first and second components and covering the opening, and a load chamber defined by a space between the second and third components and configured such that pressure in the load chamber biases the third component against the first component to seal the opening. The pressure enclosure may be a cylinder of a pump for pressurizing fluid or gas, with the first component a cylinder body, the second component an end cap and the third component a valve body, with the load chamber biasing the valve body against the cylinder body.

Abstract: A high-pressure gas compressor comprises a single-acting cam driven piston with a pressure compensation chamber disposed between the piston and the cam. A roller tappet assembly transmits reciprocating motion from the cam to the piston. A pressurized gas directed to the pressure compensation chamber offsets forces acting on the piston from the compression chamber gas pressure, thereby reducing Hertzian pressure between the tappet roller and the cam. Overall efficiency and durability can be improved by reducing friction between compressor components, for example by employing thin film coatings to reduce friction, pressurized oil lubrication systems and higher cylinder bore diameter to piston stroke ratios. The service life of gas seals and compression efficiency can be improved by thermal management strategies, including liquid-cooled compressor cylinder liners and intercoolers between compression stages.

Abstract: A dual rocking piston pump which includes a first piston with a first connecting rod eccentrically mounted to a rotor shaft and a second piston with a second connecting rod eccentrically mounted to the rotor shaft. The rotor shaft passes through a first bearing and a second bearing before being connected to a rotor body. The rotor body is disposed within a stator. The first and second bearings and stator are supported by a bracket. The bracket includes a hub which, in turn includes a first end connected to a wall at an opening in the wall. The hub also includes a second end. The first end of the hub supports the first bearing at the wall and the second end of the hub supports the second bearing. Both the first and second bearings are disposed in front of the motor or in front of both the rotor and stator.

Abstract: A suction manifold mounting for a fluid end of a high pressure pump having a frame assembly. The fluid end has a body forging with a detachable suction manifold plate. The plate is pivotally attached at opposed ends to a pair of swivel arms through a cooperating pair of yoke limbs. The swivel arms are rigidly affixed to the frame member. When attachment bolts are removed from the manifold plate, the plate may pivot from a first closed position wherein the mounting holes in the plate are aligned with mounting holes in the forging to a second open position.

Abstract: A filter to be mounted in a valve seat member for filtering liquid is proposed which can be manufactured without a drawing step, thereby improving productivity and cost performance of a piston pump in which such a filter is mounted. The filter is a flat metal plate including a main body formed with a plurality of filter holes in a central portion thereof, and a plurality of projections integrally and radially outwardly extending from a perimeter of the main body so as to be circumferentially spaced apart from each other. The filter is pushed into a filter mounting hole formed in a valve seat member of a discharge valve in a piston pump with the projections bent toward the opening of the filter mounting hole while being pressed against the inner surface of the filter mounting hole under an elastic restoring force and fixed to the valve seat member.

Abstract: A piston pump having a retaining device for retaining a spring element for restoring a closing element of a valve; the retaining device includes a receiving region for receiving and bracing the spring element and an integrally formed sealing region, in order to seal off a pressure chamber from a low-pressure region of the piston pump.

Abstract: A piston cartridge having a piston chamber, an inlet port, an outlet port, and a piston moveable between a first position and a second position. Also, the cartridge includes a first barrier positioned between the piston and the inlet port and a first sealing member moveable between the first barrier and the inlet port, wherein the first sealing member seals the inlet port when positioned adjacent to the inlet port but allows the fluid into the chamber when positioned adjacent to the first barrier. In addition, the cartridge also includes a second barrier positioned adjacent to the outlet port and a second sealing member moveable between the piston and the second barrier, wherein the second sealing member seals the outlet port when positioned adjacent thereto but allows the fluid to pass through the outlet port when positioned adjacent to the second barrier.

Abstract: The invention concerns a piston compressor, particularly a hermetic refrigerant compressor, with a compression chamber, which is limited by a valve plate arrangement having a valve plate with a suction gas opening and a pressure gas opening, a suction valve plate with a suction valve element, and a pressure valve plate with a pressure valve element. It is endeavored to achieve a good efficiency combined with a simple assembly. For this purpose, it is ensured that the pressure valve plate and the suction valve plate are located on the side of the valve plate facing the compression chamber.

Abstract: Disclosed herein is a muffler of a linear compressor. In the present invention, a center of an entry pipe of the muffler is in line with that of an inhale port of a piston. Therefore, a flow loss occurred when fluid is inhaled into the inhale port from the entry pipe can be reduced, and inhale efficiency can be improved. Furthermore, the plurality of inhale ports is eccentrically disposed in a front of the piston, and each center of the plurality of entry pipes is formed to be in line with that of the inhale ports. Not only the center but also the number of the inhale port and the entry pipe are agreed, on this account, the flow loss can be decreased and the inhale volume can be increased.

Abstract: A fixing bolt is inserted into a through hole of an end-face member and screwed with a screw hole of a valve holding member, by which a discharge valve is sandwiched by the end-face member and the valve holding member. Thus, since a thickness of the end-face member can be provided thinner, a capacity of a discharge hole of the end-face member is made smaller so that degradation of operating efficiency as well as increase of operating noise are prevented.

Abstract: The invention relates to fluidics as used in medical and diagnostic equipment and relates further to means for purifying, abstracting, filtering, detecting and/or measuring analytes in liquid samples.

Abstract: A reed valve having a plurality of tips and associated recesses is provided as a compressor suction valve with each valve tip coacting with a suction port. The recesses are located in the housing structure defining the cylinder of the compressor and are spaced a distance on the order of 0.1 inches from the tips when the suction valve is closed. The valve is secured on one side of the cylinder and each tip is located along a line from the center of the cylinder through the center, or axis, of a suction port.

Abstract: A piston pump is proposed, having a pump housing, in which housing a pump piston is guided axially movably, so that upon an actuation of the pump piston, a fluid is pumped from an intake side to a compression side, via a pump chamber bordering on the pump piston, the compression side being provided with an outlet valve, which is preceded by a damping element.

Abstract: The invention relates to a supply device for the supply of pressure fluid into at least one vehicle brake or into a pressure fluid accumulator, wherein a piston is movably arranged in an accommodating member, a carrier bears a non-return valve arranged coaxially to the piston for the purpose of ventilating a working chamber into which the piston plunges , and wherein a resetting spring is arranged between the carrier and the piston. It is the essence of the invention that a multi-piece cage allows inserting the resetting Spring into the cage parts, the cage parts comprise fastening means that lock the cage due to relative displacement of the cage parts, and the resetting spring is caged and simultaneously elastically preloaded under the relative displacement of the cage parts.

Abstract: A valve assembly for a pump includes a pump chamber and a pump head having complementary recesses formed therein which cooperate to define a valve compartment including a pocket and an opposed seat. A flexible valve element is disposed between the recesses and adapted to move between a closed position against the seat which prevents fluid flow and an open position away from the valve seat which permits fluid flow. The dimensions of the valve compartment are selected to limit the movement of the valve element in the open position, which increases the pump efficiency and prevents damage to the valve element and/or valve overlap.

Abstract: A fluid pump has a cylinder supporting a plunger and a pump housing formed with dissimilar metals. A pressing mechanism presses the cylinder and the pump housing relative to each other so that a pressurizing chamber is sealed through a pressing surface between the pump housing and the cylinder. The number of seal points can be reduce, and a reduction in reliability can be eliminated while realizing a reduction in weight of the pump housing and a reduction in cost due to increase in cutting capability, by using a soft material such as an aluminum alloy for the pump housing.

Abstract: A compressor that allows a discharge port to assume a large circumference and a large area at an exit end thereof so as to optimize the discharge resistance and the pressure-receiving area and assuring improved volumetric efficiency through reduced dead volume, includes a discharge port 5b, an entrance end of which opens into a compression chamber and an exit end that is able to open and shut with a discharge valve 43. The discharge port 5b is constituted with a recessed portion 50 formed so as to assume a specific depth measured from the exit end and a through portion 51 having a smaller sectional area than the sectional area of the recessed portion 50 with one end thereof opening at the recessed portion 50 and another end thereof opening into the compression chamber.

Abstract: A fuel pump assembly includes a pump bushing defining a dual-chambered pumping cavity, a fluid channel for shuttling fuel between the chambers, a plunger, and a plurality of fluid control valves. A first check valve is a pressure relief valve in fluid communication with an outlet of the pump bushing and with either an inlet of a second check valve or an inlet of the pump bushing. Another check valve or a control orifice may be used in parallel with the second check valve, with the third check valve or control orifice being positioned at least partially external to the fuel pump assembly. A vehicle includes a transmission, engine, a returnless high-pressure fuel pump assembly, and a low-pressure fuel line in fluid communication with an inlet side of an inlet control valve. The high-pressure fuel pump assembly inhibits a pressure pulsation from propagating through the low-pressure fuel line.

Abstract: In a stopper, by providing, in a position corresponding to a movable end vicinity of a discharge reed, a first regulation part having a predetermined clearance from the movable end vicinity of the discharge reed, since a hermetic compressor has such a two-stage spring characteristic that, until the movable end vicinity of the discharge reed touches the first regulation part, a spring characteristic is weak and, after the touch, the spring characteristic is strong, and there is obtained a discharge valve device which is easy to open and whose closing speed is rapid, it is possible to improve a delay in closing.

Abstract: A refrigerant compressor including a discharge valve system, which is configured in such a manner that the discharge valve system includes recess (124) having discharge hole (125) which communicates with a compression chamber of a cylinder and opening on the bottom surface, a discharge reed (130) for covering discharge hole (125), and stopper (132) formed of a plate spring to be arranged above discharge reed (130), that discharge reed (130) and one end of stopper (132) is fixed to the bottom surface of recess (124) and the other end of stopper (132) comes into contact with contact portion (128) so that stopper (132) and the bottom surface of recess (124) defines a space therebetween, and that discharge reed (130) is arranged in the space. The refrigerant compressor having a high compression efficiency and low variation in noise level can be provided.

Abstract: Although modern diesel fuel formulations are intended to reduce emissions of diesel engines, at least some of those modern fuels tend to have relatively low lubricity levels. The control valve assemblies described herein help to minimize any increased wear that would otherwise result from the use of such low lubricity fuels by providing a valve element, a valve guide, and an insert. The valve element is received within the valve guide and is moveable between an open position and a closed position. The insert forms a first sealed interface and a second sealed interface with the valve element and the valve guide. When the valve element is in the closed position, both of the first sealed interface and the second sealed interface are engaged. When the valve element is in the open position, only one of the first sealed interface and the second sealed interface is engaged.

Abstract: A compressor having a cylinder bore where fluid is compressed, a valve plate for partitioning the cylinder bore and a suction chamber, a suction hole provided in the valve plate and communicating the cylinder bore and the suction chamber, and a suction reed valve for opening and closing the suction hole and caused, when the valve closes the suction hole, to be in contact with a suction reed valve seal section of the valve plate. The suction reed valve seal section is located outside a suction hole-provided region. A suction reed valve support section, with which the suction reed valve can be in contact when the suction reed valve is closed, is provided also in the suction hole-provided region of the valve plate, and a valve function is provided between the outer periphery portion of the suction reed valve contact section of the suction reed valve support section and the suction reed valve. A through hole is provided in a part inside the portion where the valve function of the reed valve is provided.

Abstract: An oil-less/oil-free air brake compressor comprising a bore, a piston positioned for reciprocating in the bore, the piston having an annular recess and a rigid polymeric piston ring received within the annular recess, the piston ring having a predetermined non-circular profile in the free state.

Abstract: A hermetic compressor with internal thermal insulation, comprising: a compression cylinder having one end closed by a valve plate provided with a discharge orifice and having a front face against which is mounted a cylinder cover internally defining a discharge chamber; and a spacing duct having one inlet end hermetically mounted to the front face of the valve plate and open to the discharge orifice and an outlet end hermetically mounted to the cylinder cover and open to the interior of the discharge chamber, said spacing duct defining a hermetic fluid communication between the interior of the compression cylinder and the discharge chamber maintaining the cylinder cover spaced from the valve plate and defining, with the latter, an annular plenum around said spacing duct.

Abstract: A high-pressure gas compressor comprises a single-acting cam driven piston with a pressure compensation chamber disposed between the piston and the cam. A roller tappet assembly transmits reciprocating motion from the cam to the piston. A pressurized gas directed to the pressure compensation chamber offsets forces acting on the piston from the compression chamber gas pressure, thereby reducing Hertzian pressure between the tappet roller and the cam. Overall efficiency and durability can be improved by reducing friction between compressor components, for example by employing thin film coatings to reduce friction, pressurized oil lubrication systems and higher cylinder bore diameter to piston stroke ratios. The service life of gas seals and compression efficiency can be improved by thermal management strategies, including liquid-cooled compressor cylinder liners and intercoolers between compression stages.

Abstract: A hermetic compressor that has a pedestal of the valve plate to which a discharge reed equipped with an opening/closing part and discharge reed holding part, a spring reed equipped with a movable part and spring reed holding part, and a stopper equipped with a regulation part and stopper holding part, are fixed in this sequence, and also has a discharge valve device in which the spring reed is shaped in a substantially crank-like form is provided. A space is formed between the movable part of the spring reed and the opening/closing part of the discharge reed, and both are not adsorbed each other, thus preventing a delay in closing of the discharge reed. This makeup suppresses a decrease in freezing capacity of a fridge-freezer device and the like, thus implementing higher efficiency.