Abstract: A universal relief valve assembly (30) installed in an electric fuel pump (10) for returning fuel from an outlet portion (16) of the fuel pump back to the inlet side of the pump. A cartridge (32) is mounted in the pump and has an opening (34) extending therethrough for fuel to flow from the outlet portion of the pump back to the inlet portion of the pump. A relief valve (42) installed in the cartridge is movable from a closed position to an open position by the pressure to which the relief valve is subjected. A valve spring (52) installed in the cartridge biases the relief valve closed. The cartridge is sized to fit into a variety of fuel pumps having a range of outlet pressures, so to reduce the number of relief valve assemblies required to manufacture a line of fuel pumps.

Abstract: A cam ring 10 is slidably supported within a pump body 2, and a rotor 20 is rotatably disposed inside the cam ring. The cam ring is eccentric to a rotation shaft 22 of the rotor. The rotor carries a plurality of vanes 18 that can be advanced or retreated, in which a pump chamber 24 is formed in a space between the cam ring and the rotor. The cam ring is formed with the first and second fluid pressure chambers 14 and 16 on both sides thereof, and biased in a direction where the displacement of the pump chamber is at maximum by a spring 26. A control valve 28 is provided in which a differential pressure across a metering orifice is applied on both ends of a spool 32 and a spring 36 is disposed on the side of an end face where a downstream fluid pressure is applied. The fluid pressures of the fluid pressure chambers 14 and 16 are controlled by means of the control valve, whereby the cam ring is swung.

Abstract: A pump head for a fluid pump driven by a motor includes an inlet for receiving fluid at a first pressure and an outlet for outputting fluid at a second pressure greater than the first pressure. A relief valve cavity formed in the pump head housing includes a first portion in fluid communication with the inlet and a second portion in fluid communication with the outlet. A relief valve is disposed in the relief valve cavity with no portion of the relief positioned to block or otherwise impede the normal flow of fluid through the inlet or outlet.

Abstract: An unloader system is provided for a reciprocating gas compressor. The system includes an unloader valve assembly including a valve member controlling flow between compressor cylinder and a clearance bottle. Opening and closing of the valve member is controlled by manipulating a control pressure acting through a manifold against the stem of the valve member by means of a pressure regulator connected in series with a pressure source. When the pressure in the compressor cylinder acting on the heads of the poppet valve members exceeds the control pressure acting on the stems, the poppet valve members open, partially unloading the compressor.

Abstract: A hydraulic circuit for supplying fluid at a plurality of different pressures. The circuit comprises (a) a reservoir containing fluid at an upstream pressure level; (b) a pump for receiving a fluid from the reservoir and for raising the fluid pressure of the fluid from the upstream pressure level to a downstream pressure level; (c) a pressure conduit for receiving the fluid from the pump; (d) an adjustable relief valve for receiving fluid at the downstream pressure level from the pump; and, (e) remote control means for remotely adjusting the adjustable relief valve.

Abstract: A manifold for a hydraulic system including a pump and accessories such as valves and filters as well as gauges in which the manifold is made part of the pump in fluid communication with the output to receive hydraulic fluid and deliver it to selected accessories and to return the fluid to the reservoir of the hydraulic system all with a minimum of hoses and couplings.

Abstract: A compressor that enables the increase of compression efficiency, the prevention of abnormal temperature rising in the discharge, and the reduction of power loss, includes a compressor body 11, an intake registration valve 12 in the inlet side, and a pressure sensor 18 provided in the discharge side to be able to detect pressure.

Abstract: A hygienic, self-priming centrifugal pump (1) with a pump housing (4) provided with an inlet opening (2) and a pressure connecting piece (3), where an impeller wheel (7) can rotate inside said pump housing. The inlet opening (2) is connected with a liquid ring pump section (9) comprising an auxiliary housing (10) and a pump screw (11). The pump screw (11) is mounted on and in extension of the hub (7a) of the impeller wheel. A recycling pipe (15) for pump liquid connects the pressure connecting piece (3) of the centrifugal pump and the auxiliary housing (10) of the liquid ring pump section (9), optionally the inlet nozzle (16) or the inlet pipe (18) of the latter. All the surfaces in the pump housing (4) and the auxiliary housing (10) in direct contact with liquid should be smooth and rounded and without holes, crevices, beads or burrs.

Abstract: The invention is based on a radial piston pump (1) with a pump body (2), in which pump body (2) are placed pistons (4), and cylinders (5) arrayed radial to a cam (14) and the pistons (4) upon an inward thrust suck in fluid by means of suction side intakes (17) and upon an outward thrust, the pistons (4) impel fluid through pressure openings (7) in the outer end walls (6) of the cylinder (5) into a plenum (10). It is proposed, that in the base of the cylinders (4) respectively a connection boring (32) is made to the cam (14), which connection boring (32) is controlled by a relief valve (18). Upon the exceeding of its opening pressure the relief valve (18) opens and pressure peaks in the cylinder (5) can be diminished by means of said connection boring. At the same time, a pressure buffer between the base of the piston (4) and the bearing shell (16) is formed.

Abstract: A control device for a positive displacement pump includes a throttle device and a flow control valve. The flow control valve includes a flow control piston and is configured to regulate an unrequired excess flow of the pump at an increased speed. The throttle device is configured to produce a speed-related pressure differential in a bore section, the pressure differential being responsible for the displacement of the flow control valve and the throttle device. The throttle device is arranged in the pressure outlet (bore section) of the pump and includes a regulating pin connected to the flow control piston, having a control contour configured so that a modifiable through cross-section is created in association with a throttle bore. The control pin has a wider section in an axial displacement area of the throttle device, the area not being involved in control of the volume flow, whereby a minimum obturating section arises in the displacement area.

Abstract: In order to provide a diaphragm type fuel pump which is compact and assures a stable operation, a cavity is formed in a pump body at a position where the pump body is in contact with a fuel discharge chamber. The cavity is arranged between outer and inner parts of the pump body and perpendicularly extends to a diaphragm. The pump body has a return path communicating with a fuel intake chamber and the cavity via opposite ends thereof. A pressure regulating mechanism is housed in the cavity using a cap attached to the pump body, and is positioned inside an outer diameter of a pump chamber. This prevents the pressure regulating chamber from projecting out of the pump chamber contrary to a pressure regulating chamber of the related art, and makes the fuel pump compact. A valve seat is formed in the cap which is separate from the pump body. This facilitates machining of the valve seat.

Abstract: A capacity control system has a valve which closes off the inlet to one or more of the cylinders in a multicylinder compressor. The valve is motivated by fluid at discharge pressure which reacts against a piston to close the inlet. An orifice is positioned in the flow of the fluid at discharge pressure to control the velocity of the piston to reduce impact loading and improve reliability.

Abstract: A manifold (10) for a hydraulic system including a pump and accessories such as valves (42) and filters (88) as well as gauges in which the manifold is made part of the pump in fluid communication with the pump output to receive hydraulic fluid and deliver it to selected accessories and to return the fluid to the reservoir of the hydraulic system all with a minimum of hoses and couplings.

Abstract: An internal housing is surrounded by an external housing, forming an external space. A total quantity of fuel, pumped by the fuel feed pump into the external housing is divided in such a manner into two subquantities of fuel such that the subquantity of fuel, required by a motor, flows out of the fuel feed pump after flowing through the external space and an internal pump housing space. The other subquantity of fuel flows to a pressure regulator without flowing through the external and internal spaces of the pump.

Abstract: A rotor (4) for an eccentric screw pump or a subsurface drilling motor consists of a straight, essentially cylindrical core element (21), onto which a shell (22) is forged by a cold-forging process. The forging gives the shell (22) the helical external form required for eccentric screw pumps (1). The rotor (4) described can be produced by non-cutting shaping, which is of considerable advantage in particular in the case of large rotor dimensions, since no waste material is produced.

Abstract: An electronic control system dynamically varies the output capacity of a compressor by controlling plural valves associated with the compressor to provide pressurized air to a distribution system at an appropriate rate. The control system operates in any of three modes for standalone operation, including continuous run, auto/dual pressure band, and target pressure modes. In the first two modes, pressure bands are dynamically calculated based on load and unload values entered by an operator. These electronic control systems can also be connected in a peer-to-peer network to coordinate control of up to 16 compressors feeding the same distribution system, so as to maintain a desired target pressure in the system. A modem connected to the system supports remote diagnostics, monitoring, and control. Specialized startup, operating, and shutdown diagnostic algorithms prevent damage to the compressor and avert unsafe operating conditions.

Abstract: An air compressor comprises a compressor main body, and a capacity adjusting apparatus connected to an intake side of the compressor main body for adjusting the intake air flow into the compressor main body. The capacity adjusting apparatus is provided in an intake pipe. The intake pipe is adjacent to a discharge pipe of the compressor. A communicating passage is formed in the adjacent portion so as to introduce the compressed air discharged from the discharge pipe into the intake pipe system. The intake pipe is provided with an opening port for limiting the intake air flow into the compressor main body. The capacity adjusting apparatus opens and closes the communicating passage and the opening by means of an intake port switch valve and a discharge ventilating port switch valve which are provided in an end portion of the capacity adjusting apparatus.

Abstract: A water diverter assembly is mounted between the supply pipe and showerhead. It includes an inlet passage and outlet passage connected by a bypass valve. A remote pump is connected by inlet and outlet hoses between the inlet passage and the outlet passage, respectively. A pressure sensitive switch actuates the pump only when water pressure above a preset level is sensed at the supply pipe. The water pressure at the shower head is controlled by the bypass valve.

Abstract: The present invention relates to a centrifugal device for pumping and heating fluids which includes a cylindrical rotor having a number of bores equally spaced and arranged on the front surface according to a predetermined pattern. The fluid is subjected to motion to produce fluid heating. The arrangement of the bores on the rotor matches vortex formation in the moving fluid.

Abstract: A capacity control system has a valve which closes off the inlet to one or more of the cylinders in a multicylinder compressor. The valve is motivated by fluid at discharge pressure which reacts against a piston to close the inlet. An orifice is positioned in the flow of the fluid at discharge pressure to control the velocity of the piston to reduce impact loading and improve reliability.

Abstract: A rapid tire inflation plant comprising a low pressure high flow inflating gas source (2), an inflation device (DG), a motor (T), a compressor (C) driven by said motor and a control circuit arranged to control feed of low pressure inflating gas from said inflating gas source (2) to said compressor (C) and the feed of inflating gas at a relatively high flow and pressure to said inflation device (DG).

Abstract: A variable pressure oil pump assembly for use with a vehicle having a controller includes a pump body having an inlet, an outlet, a valve chamber, a first passage disposed between the inlet and the valve chamber, and a second passage disposed between the outlet and the valve chamber. The assembly further includes a pressure relief valve subassembly having a movable plunger that is disposed at least partially in the valve chamber for controlling flow of oil through the valve chamber so as to control outlet oil pressure at the outlet. A plunger adjustment mechanism is associated with the valve subassembly and adapted to communicate with the controller. The plunger adjustment mechanism is operable to control movement of the plunger based on control signals provided by the controller.

Abstract: A fuel system arranged to deliver fuel at high pressure to a fuel injector through a high pressure fuel line defined, at least in part, within first and second housing parts of a pressure relief valve arrangement. The first and second housing parts define first and second separable valve surfaces respectively. A clamping arrangement is provided for applying a clamping load to the first and second housing parts so as to urge first and second valve surfaces respectively thereof into substantially sealing engagement. The clamping arrangement is arranged to permit separation of the first and second valve surfaces in the event that fuel pressure within the high pressure fuel line exceeds a predetermined amount, thereby to permit fuel within the high pressure fuel line to flow to a region of relatively low pressure to relieve fuel pressure within the high pressure fuel line.

Abstract: This invention offers advantages and alternatives over the prior art by providing a dual port hydraulic fixed displacement pump which exhibits improved efficiency by limiting the volume of discharged fluid which is subjected to the line pressure of a hydraulic system through mechanical valve control. According to the present invention, a pair of discharge ports are provided, namely a first discharge port and a second discharge port. Under all operating conditions, e.g., low and high pump speed operating conditions, the fluid flowing within the first discharge port and primary discharge passageway is exposed to the working pressure of the primary line, which represents a high pressure line. The second discharge port fluidly communicates with a secondary discharge passageway which is in selective fluid communication with a low pressure line connected to a low pressure area of the pump (e.g.

Abstract: A compressor has a high-pressure relief valve and a low-pressure relief valve. The high-pressure relief valve in use for a discharge region opens when the pressure of gas in the discharge region is more than a first predetermined pressure. The high-pressure relief valve is provided with a first shim. The low-pressure relief valve in use for a suction region opens when the pressure of gas in the suction region is more than a second predetermined pressure which is lower than the first predetermined pressure. The low-pressure relief valve is provided with a second shim. The high-pressure relief valve and the low-pressure relief valve have similar structure to each other.

Abstract: A variable displacement swash plate type compressor which incorporates a conduit formed in the cylinder block to provide fluid communication between a crank chamber and one or more cylinders to eliminate the need for an orifice tube in fluid communication between a discharge chamber and the crank chamber and to increase the flow of refrigerant gas and lubricating oil to the crank chamber under all operating conditions and to increase the internal fluid pressure in the crank chamber.

Abstract: A vacuum pump including two gas friction pumps arranged parallel to each other and having each at least one stage having an inlet communicating with a common suction region and an outlet communicating with a separate discharge region, a multi-stage pump arranged downstream of the two gas friction pumps, connection conduits for communicating the separate discharge regions with a common discharge chamber, and a conduit for communicating the common discharge chamber with the suction chamber of the downstream pump.

Abstract: A scroll compressor is provided with a motor protector for stopping operation of its motor should conditions be indicative of a problem. The motor protector is sensitive to elevated temperature, and stops operation of the motor should a sensed temperature exceed a predetermined maximum. The motor protector is positioned in a chamber in a rear face of a base of the non-orbiting scroll. A port extends through the base of the non-orbiting scroll to connect a motor protector chamber to a suction chamber. Electric wires connect the motor protector to the motor and extend through this same port. In some embodiments, a pressure relief valve also communicates with the motor protector chamber. In one embodiment the motor protector chamber is enclosed by a cap and the pressure relief valve is mounted in that cap. In another embodiment the pressure relief valve extends through a wall of the non-orbiting scroll. In other embodiments, a pair of mating plugs connect the protector to the motor.

Abstract: A pumping system for a fuel injection system includes a body defining a high pressure pumping chamber, a plunger, a high pressure outlet, a high pressure fluid line connecting the pumping chamber to the outlet, a control valve along the fluid line, and a valve and restriction arrangement along the fluid line. The valve and restriction arrangement includes a restriction and a valve body. The valve body is movable between an open position in which fuel flow from the pumping chamber is generally unrestricted by the restriction and a closed position in which fuel flow from the pumping chamber is significantly restricted by the restriction to store energy in the pumping chamber. Advantageously, the high pressure restriction concept may be utilized in a pumping system for various types of rate shaping, including boot injection and square injection, in addition to pilot operation and post injection operations, and others.

Abstract: A fuel pump includes a pumping plunger reciprocable within a bore formed in a pump housing under the influence of a cam drive arrangement. The cam drive arrangement includes a reciprocable tappet member, a surface associated with the tappet member defining, in part, an auxiliary pumping chamber. A flow path interconnects the auxiliary pumping chamber and the bore such that fuel displaced from the auxiliary pumping chamber, in use, can be supplied through the flow path to the bore.

Abstract: To provide a gas compressor in which saving of power as well as improved compression performance and durability are attained by enabling reduction of vane back pressure without degrading the projectability of the vanes upon starting operation of the compressor. Scoop grooves and a high pressure supply hole are arranged so as to be spaced apart from each other, and the interval therebetween is set to an interval sufficient to ensure that a vane groove is communicated with neither the scoop grooves nor the high pressure supply hole while the vane groove moves apart from the scoop grooves toward the high pressure supply hole. Further, if there has occurred a reversed pressure relationship between a suction chamber (low-pressure chamber) and a discharge chamber (high-pressure chamber), a pressure control valve is actuated upon starting operation of the compressor to interconnect the scoop groove with the suction chamber side.

Abstract: A high pressure pump suitable for use in devices such as pressure washers or the like is disclosed wherein the pump's head assembly includes an integral start valve for allowing the fluid through the head assembly so the engine may be more easily started. When the pump reaches a predetermined rate of flow of the fluid, the start valve assembly closes to circulate the fluid through said pump assembly.

Abstract: In the case of a reciprocating pump for a high pressure cleaning appliance including a pump housing in which there is disposed at least one pumping chamber having an inlet valve, an outlet valve and a reciprocating piston that projects thereinto in sealed manner, said pump housing comprising a pump block and a pump head which abut closely together at a interface, wherein the pumping chambers and/or the connecting conduits penetrate the interface in sealed manner and, in the region of the interface, accommodate inserts that are insertable into the pumping chambers and/or the connecting conduits from the interface, said inserts being fixed between the pump block and the pump head when in their inserted position, it is proposed that the whole construction be simplified by making the inserts themselves and the region of the pumping chambers and the connecting conduits in which the inserts are accommodated out of a thermally softenable synthetic material, and by connecting the inserts to the wall of the pumping ch

Abstract: The invention relates to a hydraulic delivery device with a displacement unit which delivers a medium from a suction connection under output pressure to a pressure connection, connectable with a consumer, and under consumer pressure, and a regulating device for setting and/or limiting a volume flow delivered by the delivery device.

Abstract: The present invention provides the art with a scroll machine which has a plurality of built-in volume ratios along with their respective design pressure ratios. The incorporation of more than one built-in volume ratio allows a single compressor to be optimized for more than one operating condition. The operating envelope for the compressor will determine which of the various built-in volume ratios is going to be selected. Each volume ratio includes a discharge passage extending between one of the pockets of the scroll machine and the discharge chamber. All but the highest volume ration utilize a valve controlling the flow through the discharge passage.

Abstract: A fluid pump having a motor operably coupled to a pump assembly, the motor and pump assembly acting cooperatively to pressurize a fluid includes a pressure switch being in communication with the fluid under pressure and being in communication with the motor for sensing the fluid pressure and controlling the operation of the motor to maintain a selected fluid pressure. A method of controlling fluid pressure in a fluid pump, the fluid pressure being generated by activating a pump motor to operate a pump assembly.

Abstract: An integrated instrument assembly for compressors, having a pressure switch and a pressure reducer connected to each other by a pneumatic circuit, is connectable to a compressor having a compressed-air tank communicating with the pneumatic circuit; the pressure switch and pressure reducer being supported on a supporting member having the pneumatic circuit.

Abstract: In order to provide a diaphragm type fuel pump which is compact and assures a stable operation, a cavity is formed in a pump body at a position where the pump body is in contact with a fuel discharge chamber. The cavity is arranged between outer and inner parts of the pump body and perpendicularly extends to a diaphragm. The pump body has a return path communicating with a fuel intake chamber and the cavity via opposite ends thereof. A pressure regulating mechanism is housed in the cavity using a cap attached to the pump body, and is positioned inside an outer diameter of a pump chamber. This prevents the pressure regulating chamber from projecting out of the pump chamber contrary to a pressure regulating chamber of the related art, and makes the fuel pump compact. A valve seat is formed in the cap which is separate from the pump body. This facilitates machining of the valve seat.

Abstract: An electric fuel pump comprising a pump casing assembly having a fuel inlet port and an outlet port and a rotary member driven by an electric motor disposed within the pump casing assembly for pumping fuel from the outlet port. A fuel discharge port supplies the fuel from the outlet port to an engine, and a pressure regulator is disposed for regulating the pressure of the fuel to be discharged from the fuel discharge port. The pressure regulator regulates the pressure of the fuel from the outlet port by returning the fuel to the vicinity of the inlet port when the pressure of the fuel from the outlet port is equal to or higher than a predetermined pressure.

Abstract: A medium and high pressure pump systems supplies a cryogenic fluid from a storage tank and methods of operating such systems to remove both liquid and vapor from the storage tank to reduce the need for venting. The system comprises a pump that is operable to pump cryogenic liquid or a mixture of cryogenic liquid and vapor. In accordance with the method, mass flow rate through the pump is controlled by selecting one of at least two operating modes. In a first operating mode a high flow rate is achieved by supplying cryogenic liquid to the pump from the storage tank to substantially fill a compression chamber within the pump with liquid. In a second operating mode, a lower mass flow rate is achieved by selectively simultaneously supplying liquid and vapor from the storage tank to the pump, with the vapor fraction being higher in the second operating mode compared to the first operating mode.

Abstract: A pumping system for a fuel injection system includes a body defining a high pressure pumping chamber, a plunger, a high pressure outlet, a high pressure fluid line connecting the pumping chamber to the outlet, a control valve along the fluid line, and a valve and restriction arrangement along the fluid line. The valve and restriction arrangement includes a restriction and a valve body. The valve body is movable between an open position in which fuel flow from the pumping chamber is generally unrestricted by the restriction and a closed position in which fuel flow from the pumping chamber is significantly restricted by the restriction to store energy in the pumping chamber. Advantageously, the high pressure restriction concept may be utilized in a pumping system for various types of rate shaping, including boot injection and square injection, in addition to pilot operation and post injection operations, and others.

Abstract: A pneumatically operated hydraulic pump includes a cylinder housing accommodating a main piston to subdivide the housing interior in two working chambers. The main piston is connected to a hydraulic piston for joint reciprocation so that the hydraulic piston can carry out a suction stroke when the main piston moves to one end position and a pressure stroke when the main piston moves to the other end position. Arranged laterally to the cylinder housing is a control mechanism for regulating a flow of working fluid alternately to the working chambers. The control mechanism includes a plastic valve casing for accommodating a control piston having opposite end faces of different size to define different effective areas and thereby realize reciprocation of the control piston by the working fluid. A slide shoe is guided in the valve casing for conjoint movement with the control piston.

Abstract: A valve combination for vibration pumps performs multiple functions of self-priming, compensation of negative pressure and protection against over pressure. A body (12) contains a non-return valve (18). A valve (26) releases air and compensates for negative pressure. A safety valve (48) vents accidental over pressure originating, for example, from a boiler source. The valve (26) in order to achieve negative pressure compensation, comprises a plug provided with grooves or incisions (40a-c) for favoring the external flow of air subject to negative pressure.

Abstract: A variable capacity swash plate type compressor 10, which incorporates an inlet port 40 disposed in a crankcase 36 leading to a crank chamber 38. The inlet port 40 places the crank chamber 38 in the active flow path of a refrigerant gas for the compressor 10 and eliminates the need for an orifice tube in fluid communication with a discharge chamber 22 and the crank chamber 38 thereby increasing the maximum capacity of the compressor 10.

Abstract: An unloader system is provided for a reciprocating gas compressor having a cylinder, a piston reciprocably mounted in the cylinder, a rotatable crankshaft connected to the piston, a suction valve assembly, and a discharge valve assembly for selectively communicating suction and discharge lines with the compressor cylinder. An unloader valve assembly including a valve seat structure, valve guard, and multiple poppet valve members is provided to allow selective communication between the compressor cylinder and a clearance bottle. The opening and closing of the unloader valve assembly is controlled by manipulating a control pressure acting through a manifold against the stem ends of the poppet valve members by means of a pressure regulator connected in series with a pressure source. When the pressure in the compressor cylinder acting on the heads of the poppet valve members exceeds the control pressure acting on the stems, the poppet valve members open, partially unloading the compressor.

Abstract: A capacity control valve (17) for use in a clutchless, variable capacity compressor includes a central rod plunger (34) that is shifted axially in one direction, against a spring (39), by an energized coil (40), when the compressor is in a greater than minimum capacity condition. For the minimum capacity position, the rod plunger (34) is released by the de energized coil (40) to be pushed by spring (39) in the opposite direction to a solid, pre determined position. A by pass passage (42) interconnecting a discharge pressure chamber (20) and a suction pressure chamber (26) runs in parallel to the rod plunger (34), normally closed off by its own spring loaded shut off valve (44). When the coil 40 is de energized to release the plunger (34), it engages the shut off valve, opening the by pass passage and opening the discharge pressure chamber (20 to the suction pressure chamber (26).

Abstract: The integrated electric fuel pump provides at least three sets of four internally threaded bores, one set on one side of the fluid pump housing, a second set oppositely located with respect to the first set, and a third set disposed toward the end of the fluid pump housing. This enables the integrated electric fuel pump to be secured with four threaded members, complete with rubber isolators, and oriented in three ways, two involving a 180° rotation of the fuel pump which will enable the inlet and outlet to change sides. At one end of the fluid pump housing, an electric motor is integrated with the brushes of the motor supported by the integrated pump housing to enable larger brushes and longer urged brush support structures. The metal wall of the housing draws heat from the brushes of the electric motor, and provides spreading and larger surface radiation of the heat along the pump body as well as some heat transfer into the fuel passing within the pump body.

Abstract: A variable capacity swash plate type compressor 10 incorporates a pressure relief valve 43 in fluid communication with a suction chamber 20 and a crank chamber 40. The pressure relief valve 43 prevents over pressurization in the crank chamber 40 to minimize friction and forces acting on the components of the compressor 10.

Abstract: A reciprocating compressor that includes an auxiliary port 38 in series with a check valve 40 to move fluid at an intermediate pressure that is between the main suction and discharge pressures. Piston 31 normally covers the auxiliary port during a portion of its stroke. In one embodiment the check valve 40 is oriented so that fluid flows into the compressor. The piston 31 uncovers the auxiliary port 38 during the early part of the down stroke to allow fluid in through the port. As the piston 31 continues to move down it covers the auxiliary port, which drops pressure in chamber 37 to allow fluid to enter through a main suction valve 34. In other embodiments the orientation of the check valve is reversed and auxiliary port acts as an auxiliary discharge port. Multiple auxiliary ports may be used in a single cylinder to achieve multiple suction and/or discharge pressures.

Abstract: A pressure relief valve assembly for an air conditioning system of a vehicle includes a compressor hose block having an inlet port and an outlet port. The inlet port is for connection to a low pressure gas and the outlet port is for connection to high pressure gas of the air conditioning system. The compressor hose block also has a connecting port interconnecting the inlet port and the outlet port. The pressure relief valve assembly further includes a valve disposed in the connecting port to allow the high pressure gas to pass from the outlet port to the inlet port when a pressure of the high pressure gas reaches a predetermined level.