Abstract: An electromagnetic cradle includes a support frame, a swinging table, multiple abutting members, a magnetic box, and an electromagnetic device. The support frame includes two support rods each provided with multiple rollers. The abutting members are secured to the bottom of the swinging table and rest on the rollers respectively. The magnetic box is secured to the bottom of the table board. The electromagnetic device is secured to the support frame. The electromagnetic device is located under and corresponds to the magnetic box. The electromagnetic device produces a magnetic force to attract or repel the magnetic box that is mounted on the swinging table, so as to pull or push the swinging table, such that the swinging table horizontally swings successively and reciprocatingly.

Abstract: The present invention discloses a pressure converter system for sustainably forcing saline water through a semi-permeable membrane, comprising a hydraulic oil pump, a hydraulic oil cylinder comprising pressurized oil generated from the hydraulic oil pump, a sustainable energy source for powering the hydraulic oil pump, a saline water cylinder containing saline water, wherein the hydraulic oil cylinder and the saline water cylinder are connected using a piston and an electrical circuit for determining a direction of movement of the piston. This system may be developed to a stand-alone desalination facility comprising a ducted windmill that can harvest energy from a wide range of wind speeds, especially very low wind speeds. Because of the above, the present invention successfully converts mechanical energy to high pressure that is required to produce fresh water from saline water.

Abstract: A compressor system includes a screw compressor and a controller. The screw compressor includes a slide valve selectively actuatable between a first position and a second position to facilitate modulating a capacity of the screw compressor between fully-loaded and fully-unloaded. The controller is communicably coupled to the slide valve. The controller is configured to receive a chilled fluid temperature setpoint for a fluid in heat transfer communication with a refrigerant of the refrigeration circuit; receive temperature data indicative of a chilled fluid temperature of the fluid; determine a difference between the chilled fluid temperature and the chilled fluid temperature setpoint; and provide one of a load command and an unload command to the slide valve based the difference between the chilled fluid temperature and the chilled fluid temperature setpoint. According to an embodiment, the controller does not receive feedback from the screw compressor regarding a position of the slide valve.

Abstract: Devices for sealing and inflating inflatable objects, in particular for sealing and inflating motor vehicle tires, wherein the devices have as a source of compressed gas a compressor unit, which is formed as a reciprocating piston compressor driven by a slider crank mechanism and has a piston moved in an oscillating manner in a cylinder, and wherein the piston and the cylinder delimit a compression chamber and the cylinder is closed on the output side by a cylinder head with an outlet valve.

Abstract: A fuel supply device includes: a linear actuator; a reciprocating pump having a boosting piston driven by the linear actuator and configured to reciprocate in an axial direction, the reciprocating pump being configured to suck the fuel when the boosting piston moves in a first direction and configured to boost and eject the fuel when the boosting piston moves in a second direction; and a controller configured to control driving of the linear actuator so as to adjust an amount of the fuel ejected from a boosting cylinder per reciprocating time by adjusting a ratio of a fuel ejection time and a fuel suction time of the reciprocating pump without changing the reciprocating time of the boosting piston in accordance with a load of the internal combustion engine. The adjustment adjusts a stroke length of the boosting piston and a moving speed of the boosting piston in the second direction.

Abstract: Disclosed is a device that includes a natural-gas compression system having a natural-gas powered combustion engine, a compression cylinder configured to receive natural gas and output compressed natural gas, a piston disposed in the compression cylinder and configured to translate through the compression cylinder in response to mechanical power received from the natural-gas powered combustion engine, and a variable-volume head mounted to the compression cylinder and configured to vary a compressed volume of the compression cylinder. In some instances, the variable-volume head includes a head body, an adjustment screw rotatably coupled to the head body, a plug moveable in threaded engagement with the adjustment screw, and an anti-rotation device coupled to the plug, the head body, or both. The anti-rotation device may be configured to impede the plug from rotating relative to the head body as the adjustment screw rotates.

Abstract: An oscillating armature pump, in particular high-pressure oscillating armature pump, for a household appliance, with a piston guidance for guiding a piston element, with a pump spring provided for supplying an actuation force onto the piston element, and with a housing unit comprising at least one flux-conducting element which is provided to conduct a magnetic flux generated by a magnetic actuator. It is proposed that the flux-conducting element is in a mounted state arranged in a radial direction between the pump spring and the piston guidance.

Abstract: A linear compressor is provided. The linear compressor includes a casing and a machined spring. An inner back iron assembly is fixed to the machined spring at a middle portion of the machined spring. A driving coil is operable to move the inner back iron assembly in order to reciprocate a piston within a chamber of a cylinder assembly.

Abstract: A linear compressor is provided. The linear compressor includes a piston slidably received within a chamber of a cylinder assembly. A machined spring of the linear compressor extends between an inner back iron assembly of the linear compressor and the cylinder assembly in order to couple the inner back iron assembly to the cylinder assembly.

Abstract: A linear compressor is provided. The linear compressor includes a machined spring. An inner back iron assembly is fixed to the machined spring at a middle portion of the machined spring. A driving coil is operable to move the inner back iron assembly in order to reciprocate a piston within a chamber of a cylinder assembly.

Abstract: A security system for a pneumatic accumulator, the pneumatic accumulator being connectable with a pump and with a pneumatic apparatus by, respectively, a first and second connecting duct is described. The security system has a) a pneumatic bladder for containing high pressure gas, and b) flow distribution means connected with the first and second connecting ducts to the pneumatic accumulator and the pneumatic bladder, the flow distribution means being able to pass from a first operating position to a second operating position, in which the flow distribution means connects the first and second connecting ducts with the pneumatic bladder (40) pneumatic plant is also described.

Abstract: Systems and methods for maintaining substantially a baseline pressure in a chamber of a pumping apparatus are disclosed. Embodiments of the present invention may serve to control a motor to compensate or account for a pressure drift which may occur in a chamber of the pumping apparatus. More specifically, a dispense motor may be controlled to substantially maintain a baseline pressure in the dispense chamber before a dispense based on a pressure sensed in the dispense chamber. In one embodiment, before a dispense is initiated a control loop may be utilized such that it is repeatedly determined if the pressure in the dispense chamber is above a desired pressure and, if so, the movement of the pumping means regulated to maintain substantially the desired pressure in the dispense chamber until a dispense of fluid is initiated.

Abstract: Embodiments of the invention provide a system, method and computer program product for reducing the hold-up volume of a pump. More particularly, embodiments of the invention can determine, prior to dispensing a fluid, a position for a diaphragm in a chamber to reduce a hold-up volume at a dispense pump and/or a feed pump. This variable home position of the diaphragm can be determined based on a set of factors affecting a dispense operation. Example factors may include a dispense volume and an error volume. The home position for the diaphragm can be selected such that the volume of the chamber at the dispense pump and/or feed pump contains sufficient fluid to perform the various steps of a dispense cycle while minimizing the hold-up volume. Additionally, the home position of the diaphragm can be selected to optimize the effective range of positive displacement.

Abstract: A hydraulic system includes a cylinder assembly with a rod, a pressurized fluid source, a fluid tank, and a control valve. The control valve is fluidly connected to the cylinder assembly. The hydraulic system also includes a line relief, first makeup valve, and second makeup valve fluidly connected to a head end of the cylinder assembly. The second makeup valve is configured to provide fluid flow to the head end of the cylinder assembly when the rod is urged toward an extended position and the control valve is in a neutral position.

Abstract: Embodiments of the systems and methods disclosed herein utilize a brushless DC motor (BLDCM) to drive a single-stage or a multi-stage pump in a pumping system for real time, smooth motion, and extremely precise and repeatable position control over fluid movements and dispense amounts, useful in semiconductor manufacturing. The BLDCM may employ a position sensor for real time position feedback to a processor executing a custom field-oriented control scheme. Embodiments of the invention can reduce heat generation without undesirably compromising the precise position control of the dispense pump by increasing and decreasing, via a custom control scheme, the operating frequency of the BLDCM according to the criticality of the underlying function(s). The control scheme can run the BLDCM at very low speeds while maintaining a constant velocity, which enables the pumping system to operate in a wide range of speeds with minimal variation, substantially increasing dispense performance and operation capabilities.

Abstract: An electrical signal input type displacement control device capable of reducing pipes on hydraulic equipment, and hydraulic equipment including the same. The pump equipment includes two the pump units. Electrical regulators are disposed for the pump units. In each of the electrical regulators, a solenoid proportional valve changes a supply status of driving oil. A pilot piston activates a servo switching valve in accordance with a supply status of the supplied driving oil, and controls a supply status of mechanism driving oil supplied to a servo mechanism. Servo mechanisms change the capacities of the pump units in accordance with the supply status. In the electrical regulators, a driving oil passage connects the input port to an inter-pump passage.

Abstract: Overpressure of refrigerant in a refrigerant circuit is avoided. A swash plate type variable displacement compressor includes a muffler (muffler space 123) at the top of a cylinder block 101 thereof. The muffler space 123 is connected to a communication passage communicating with a discharge chamber of the compressor, and in this connecting portion, a check valve 200 for suppressing a backflow of the refrigerant is provided. The muffler space 123 communicates with a discharge-side external refrigerant circuit via a discharge port. An inlet port of the high-pressure relief valve 250 in the muffler space 123 communicates with the muffler space 123 located on downstream side of the check valve 200, and an outlet port thereof communicates with a crank chamber 105 of the compressor through communication passages 101c and 101d of the cylinder block 101. The crank chamber 105 communicates with a suction chamber of the compressor through a gas bleeding passage.

Abstract: A controllable variable volume clearance pocket for reciprocating compressor cylinders is disclosed. The invention includes a device for varying the clearance volume of a variable volume clearance pocket in a controlled manner. The device can be used repeatedly to change the compressor cylinder clearance volume as required to control compressor capacity and power required from the compressor driver. The device is typically mounted on the outer or head end of a reciprocating compressor cylinder, but can also be scaled and configured for use either in conjunction with a variable clearance volume unloader operating over a reciprocating compressor valve pocket or a special port in a reciprocating compressor body.

Abstract: Embodiments disclosed provide a customizable dispense system implementing modular architecture, the customizable dispense system comprising a smart controller configured to operate various pneumatic pumps and motor pumps in various semiconductor manufacturing processes that are sensitive to defects in printed patterns. The smart controller is configured to, upon switching from communicating with a first pump to a second pump, automatically recognize the second pump and apply a control scheme to control the second pump, which may be a motor pump or a pneumatic pump. The switching may be due to physical disconnection of the first pump and physical connection of the second pump or it can be entirely done via software. The smart controller may be connected to track and a variety of devices, including smart filters.

Abstract: A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

Abstract: Embodiments of the present, invention provide a system and method for reducing the hold-up volume of a pump. More particularly, embodiments of the present invention provide a system and method for determining a home position to reduce hold-up volume at a dispense pump and/or a feed pump. The home position for the diaphragm can be selected such that the volume of the chamber at the dispense pump and/or feed pump contains sufficient fluid to perform the various steps of a dispense cycle while minimizing the hold-up volume. Additionally, the home position of the diaphragm can be selected to optimize the effective range of positive displacement.

Abstract: A peristaltic pump is able to deliver accurate volumes over the life of a pump set that is operated on by the pump to drive the flow of fluid. The pump delivers fluid in small volumes or aliquots. In order to deliver fluid at any particular selected flow rate, the pump determines how often the rotor will rotate. The pump is able to calculate aliquot volume based on selected flow rate, but also on a factor that compensates for changes in the dimensions of the pump set over its life.

Abstract: Embodiments of the systems and methods disclosed herein utilize a brushless DC motor (BLDCM) to drive a single-stage or a multi-stage pump in a pumping system for real time, smooth motion, and extremely precise and repeatable position control over fluid movements and dispense amounts, useful in semiconductor manufacturing. The BLDCM may employ a position sensor for real time position feedback to a processor executing a custom field-oriented control scheme. Embodiments of the invention can reduce heat generation without undesirably compromising the precise position control of the dispense pump by increasing and decreasing, via a custom control scheme, the operating frequency of the BLDCM according to the criticality of the underlying function(s). The control scheme can run the BLDCM at very low speeds while maintaining a constant velocity, which enables the pumping system to operate in a wide range of speeds with minimal variation, substantially increasing dispense performance and operation capabilities.

Abstract: Systems and methods for maintaining substantially a baseline pressure in a chamber of a pumping apparatus are disclosed. Embodiments of the present invention may serve to control a motor to compensate or account for a pressure drift which may occur in a chamber of the pumping apparatus. More specifically, a dispense motor may be controlled to substantially maintain a baseline pressure in the dispense chamber before a dispense based on a pressure sensed in the dispense chamber. In one embodiment, before a dispense is initiated a control loop may be utilized such that it is repeatedly determined if the pressure in the dispense chamber is above a desired pressure and, if so, the movement of the pumping means regulated to maintain substantially the desired pressure in the dispense chamber until a dispense of fluid is initiated.

Abstract: A controller for a system having at least one variable-capacity, pulse-width modulated compressor and at least one fixed-capacity compressor is provided. The controller may include processing circuitry that modulates the at least one variable-capacity, pulse-width modulated compressor to any capacity substantially between ten percent capacity and one hundred percent capacity. The processing circuitry may determine a desired capacity of the at least one variable capacity, pulse-width modulated compressor based on a load sensor signal and a current run percentage of the at least one variable capacity, pulse-width modulated compressor and may toggle the at least one fixed-capacity compressor between a run mode and a shutdown mode based on the desired capacity of the at least one variable-capacity, pulse-width modulated compressor.

Abstract: The present invention discloses a control apparatus for a linear compressor which can vary a cooling force and prevent an inrush current. The control apparatus for the linear compressor includes a coil winding body laminated on the linear compressor, a first capacitor connected in series to the coil winding body, a capacitance varying unit being formed in a parallel structure to the first capacitor, and having a capacitor switch, and a control unit for inducing an output change of the linear compressor, by varying the whole capacitance of the control apparatus by controlling the capacitor switch.

Abstract: A multi-channel pump includes a pump chamber, an inflow passage connected to the pump chamber, two or more outflow passages connected to the pump chamber, outflow side active valves provided so as to correspond to the outflow passages, and a movable body reciprocated to change a volumetric capacity of the pump chamber. The movable body may be a piston reciprocated within a cylinder that is connected to the pump chamber. A control method for a multi-channel pump includes an initial discharge step between a suction step and a discharge step. The multi-channel pump may be preferably utilized in a fuel cell.

Abstract: In an adjusting device, in particular for a motor vehicle, which includes at least one adjusting unit for adjusting the pressure of a pressure medium in accordance with at least one parameter, the adjusting unit includes a first and a second throttle point having different dependences on the parameter in order to obtain a pressure difference dependent on the parameter for controlling the supply of the pressure medium.

Abstract: A reducing agent pump has a pump inlet part and a pump outlet part closing off the pump body at its ends. One or both of the inlet and outlet parts is of two-part construction, with a closure element and another element. The two elements are prestressed relative to one another with a spring element, so that in the event of a pressure which exceeds the spring force of the spring element, a relative movement can be carried out between the two elements of the two-part member. This makes it possible to absorb an increase in the volume of the reducing agent inside the pump body caused by freezing and therefore to prevent damage to the reducing agent pump.

Abstract: A heat pump water heater system includes a compressor that has a variable clearance volume that can be selectively controlled to control the mass flow rate of refrigerant from the compressor. Under higher ambient air temperature conditions, the variable volume is increased to keep refrigerant in a variable clearance volume chamber and to decrease the mass flow rate of the refrigerant from the compressor. Under lower ambient air temperature conditions the variable volume is decreased to increase the mass flow rate. The variable clearance volume allows for maintaining optimum system performance under a variety of ambient air temperature conditions.

Abstract: A dual capacity compressor, which can maintain a fixed eccentricity and stable operation, even when the compressor is rotated in both the regular and reverse directions in order to provide multiple compression capacities, is provided. This dual capacity compressor implements an improved key member and associated key member fitting parts to inhibit relative motion of the crank pin and the eccentric sleeve during operation, so as to reduce or eliminate a destabilizing effect due to centrifugal forces on the eccentric sleeve and external forces applied through the connecting rod.

Abstract: A variable-capacity vane pump comprising a body (1) comprising a cavity (2) in which a mobile ring (3) can move, inside which a hub (4) is located which is rotatable around a fixed axis (R) and equipped with vanes (5) which during rotation are supported against an inner face of the mobile ring (3), displacing means for moving the mobile ring (3) as a function of a control pressure between a position centered on the axis of rotation of the hub (4) and an extreme eccentric position with respect to the axis of rotation of the hub (4). According to the invention, the displacing means of the mobile ring (3) comprise a recess (10) provided in the wall of the cavity (2) of the body (1), and a projection (9) formed on the outer face of the mobile ring (3) and designed to slide in the recess (10) of the cavity (2) of the body (1) so as to form a control chamber in which the control pressure is applied.

Abstract: A variable capacity rotary compressor capable of varying a compression capacity thereof. The variable capacity rotary compressor includes a housing defined therein with first and second compressing chambers having different volumes, a rotating shaft adapted to rotate in the first and second compressing chambers, a compressing unit arranged in the first and second compressing chambers, and adapted to perform a compression operation in a selected one of the first and second compressing chambers in accordance with a change of a rotating direction of the rotating shaft, and a drive motor adapted to rotate the rotating shaft in a first direction or in a second direction, the drive motor being variable in rotating speed in accordance with an electrical control operation.

Abstract: An apparatus and method of controlling a linear compressor. The apparatus includes a current detection unit to detect current, a control unit to determine whether a collision between a piston and a valve occurs, and controlling a stroke of the linear compressor, and a compressor drive unit to perform adjustment of the stroke of the linear compressor. The method includes presetting a maximum stroke and a collision point according to a load, selectively increasing and reducing a stroke of the linear compressor according to a variation in the load, and controlling the stroke.

Abstract: A variable displacement compressor has a drive shaft, a rotor supported by the drive shaft, a drive plate supported by the drive shaft and a hinge mechanism located between the rotor and the drive plate. The hinge mechanism includes a cam, which is located on the rotor, and a guide portion, which is located on the drive plate. The cam has a cam surface, which has a predetermined profile. One of the cam surface and the guide portion slides against the other in accordance with inclination of the drive plate. The guide portion traces a path corresponding to the profile of the cam surface with respect to the cam. The path includes a first path corresponding to a small displacement region of the compressor and a second path corresponding to a large displacement region of the compressor. The profile of the cam surface is determined such that the first path and the second path bulge in a direction opposite to each other to compensate for fluctuation of a top dead center position of the piston.

Abstract: A high pressure fuel pump having a variable fuel injection rate, including a pump body, a pump cylinder formed in the pump body and a piston reciprocable within the pump cylinder, which defines a pressurization chamber. The pump piston has a reduced diameter portion which provides a primary piston. A piston annulus is slidably mounted thereon and provides a secondary piston. An annular actuation chamber adjoins the secondary piston opposite the pressurization chamber. An actuation passage is provided between a return fuel drain and the actuation chamber, which is selectively open or closed passively by pump piston movement and/or dynamically by operation of an actuation solenoid valve. If the actuation chamber passage is open, then during the pressurization stroke the secondary piston will remain stationary relative to the pump body, but if it is closed then the secondary piston must stroke in unison with the primary piston.

Abstract: A scroll type machine incorporates a unique system for monitoring the status of a valve which is used to control the capacity of the compressor. The valve functions to open and close a fluid passage between two areas of the compressor for capacity modulation. By monitoring the temperature of the fluid after the valve, it can be determined whether or not the valve is functioning. If the temperature fluctuates, the valve is functioning. If the temperature is constant, the valve is not operating properly. Another embodiment monitors the pressure within the fluid line controlled by the valve.

Abstract: A device (10) for continuous regulation of the gas flow rate processed by a reciprocating compressor, wherein the reciprocating compressor has at least one first compression piston (35), which is associated with a first cylinder (51), and can create a pressure which is variable over a period of time, and a second piston (13), which acts inside a second cylinder (52), which is in free communication with the said first compression cylinder (51), associated with the said first piston (35), and which acts on an additional dead space (11). The device includes a third fluid mechanics cylinder (12), which moves the said piston (13) of the dead space (11), wherein the third fluid mechanics cylinder (12) is activated by means of a compressed fluid, supplied by means of an independent hydraulic system (14), in order to obtain continuous variation of the dead space (11).

Abstract: A hydraulically actuated servo piston and hydraulic advance piston are integrated into the cam follower of a unit pump or injector to provide variable advance for an injection event produced by the pump or injector. The servo piston is nested in the advance piston with fluid passageways in the advance piston selectively opened or closed by movement of the servo piston. The full pressure of a hydraulic pump is available to the advance piston for powering the advance function, while stepwise reduced levels of hydraulic pressure from the same hydraulic pump are applied to control movement of the servo piston. A damping orifice restricts flow of hydraulic fluid to and from the servo piston.

Abstract: A regulatable pump, in particular a vane pump, is provided with a rotor, with a rotor body and with at least one guide ring and with a cam ring. The eccentricity of the cam ring can be adjusted by means of a regulating piston, a journal of the cam ring lying between a spring-pretensioning means and the regulating piston. At maximum eccentricity, the cam ring bears on the outside by means of a bearing part of its circumferential wall against a bearing surface on the inside of the housing.

Abstract: A fuel pump comprises a pumping plunger reciprocable within a plunger bore under the action of a cam drive arrangement. The cam drive arrangement comprises first and second surfaces defining therebetween a chamber, the volume of which can be controlled to control the spacing of the first and second surfaces so as to permit control of the axial length of the cam drive arrangement. The first surface may be defined by a tappet member which acts to transmit a force from the cam drive arrangement to the pumping plunger, the second surface being defined by a piston member which is slidable within a tappet bore formed in the tappet member. The invention also relates to an arrangement for use in a fuel pump comprising a pumping plunger which is reciprocable within a plunger bore under the action of a drive arrangement and a tappet member which is slidable within a further bore provided in a housing for transmitting a force from the drive arrangement to the pumping plunger.

Abstract: An engine is disclosed. According to one embodiment of the present invention, the engine comprises a compressor, and combustor, and an expander. The compressor compresses ambient air. The combustor bums the compressed air, and produces exhaust gasses. The expander receives the exhaust gases from the combustor, and expands the exhaust gasses. The compressor may be a gerotor compressor or a piston compressor having variable-dead-volume control. The expander may be a gerotor expander or a piston expander having variable-dead-volume control. In another embodiment, an engine comprises a piston compressor, a combustor, a piston expander, and a pressure tank. The piston compressor compresses ambient air. The combustor bums the compressed air, and produces exhaust gasses. The piston expander receives the exhaust gasses from the combustor, and expands the exhaust gasses. The pressure tank receives and stores the compressed air from the compressor.

Abstract: An engine is disclosed. According to one embodiment of the present invention, the engine comprises a compressor, and combustor, and an expander. The compressor compresses ambient air. The combustor burns the compressed air, and produces exhaust gasses. The expander receives the exhaust gases from the combustor, and expands the exhaust gasses. The compressor may be a gerotor compressor or a piston compressor having variable-dead-volume control. The expander may be a gerotor expander or a piston expander having variable-dead-volume control. In another embodiment, an engine comprises a piston compressor, a combustor, a piston expander, and a pressure tank. The piston compressor compresses ambient air. The combustor burns the compressed air, and produces exhaust gasses. The piston expander receives the exhaust gasses from the combustor, and expands the exhaust gasses. The pressure tank receives and stores the compressed air from the compressor.

Abstract: A rotary device (11) has a first rotor (12) rotatable about a first axis and having at its periphery a recess (14). A second rotor (13) is counter-rotatable to said first rotor (12) about a second axis, parallel to said first axis, and has a radial lobe (15). The first and second rotors (12,13) are coupled for rotation and are intermeshed such that, for a portion of the rotation of the rotors (12,13), there is defined between the first and second rotors (12,13) a transient chamber of volume which progressively decreases on rotation of the rotors (12,13). Means (27,28) are provided for monitoring the clearance between the rotors (12,13). Means for adjusting the clearance between the rotors (12,13) are provided.

Abstract: A high pressure gas compressor in one embodiment having an internal two staged compression with a compression chamber formed in part by a positive displacement, stepped piston and cylinder configuration, providing a first stage compression by an enlarged diameter segment of the piston and a second stage compression provided by a smaller diameter segment of the piston, and in another embodiment having an internal, single stage compression with a high compression ratio.

Abstract: In association with a straight-cylinder, reciprocating gas compressor, hydraulic circuitry and valving is provided to track movement of an intake valve which cooperates with an end of the compressor to define a clearance volume. The valving is selectively operative to cause the intake valve to reposition in more proximity to the end of the compressor, or more in proximity to its confronting discharge valve.

Abstract: Embodiments of lubricant pumps for machines wherein the pump comprises a pumping plunger slidably supported within a bore. The quantity of lubricant delivered during a stroke of the pumping plunger is adjusted by means of a stop plunger which is mounted within the bore and which is contacted by the pumping plunger for limiting its degree of movement. In this way it is possible to maintain a minimum clearance volume under all conditions of stroke of the pumping plunger. Both mechanical and electrical drives for the pumping plunger are disclosed. In two embodiments of the invention, the stop plunger is controlled in response to the operation of the throttle valve of the engine. In two other embodiments the amount of lubricant pump is dependent upon speed of the engine but a connection to the throttle control is not employed and the operation is such that non-linear relationships between engine speed and amount of lubricant pump may be employed.

Abstract: An auxiliary chamber is connected to the main pumping chamber of a liquid dispensing pump. The auxiliary chamber includes a resilient rolling diaphragm in fluid communication with the fluid in the main pumping chamber and is expandable for receiving liquid from the main pumping chamber during an output stroke with an adjustable stop member being located behind the diaphragm for restricting the displacement of the diaphragm by the volume of fluid entering the secondary chamber from the pumping chamber and thus controlling the output from the pump by controlling the net internal pump chamber volume.

Abstract: A screw pump having a pair of screw rotors meshed with each other and rotatably supported in a housing having an intake port provided at one end and a piston movably provided at the other axial end of the housing, which piston defines a discharge port in cooperation with the housing. The movement of the piston in a direction substantially perpendicular to the axes of the screw rotors enables the distance between a discharge starting position of the discharge port and the intake port to be varied, so that the internal compression ratio can be varied. This arrangement ensures that the size of the housing will not be increased and any disadvantage due to the difference in thermal expansion along the length of the housing can be overcome.

Abstract: Pump units comprising a metering reciprocating pump with adjustable length of stroke are used in packing machines for filling of packing containers with a metered quantity of flowable contents, e.g. yogurt. Adjustments in the length of stroke in order to adapt the amount of filling goods to the volume of the packing container interferes with the breaking sequence at the extreme position of the piston and alters the time for each pumping stroke. These drawbacks are avoided by means of an arrangement which includes a movable braking device for the piston as well as a valve arrangement which is linked to the braking device and serves to adapt the speed of the piston to the length of stroke.