Abstract: Methods and systems are provided for assessing a state of a vent hose that fluidically couples a crankcase of an engine to an engine air intake system. In one example, a method may include sealing the crankcase from the vent hose, initiating cranking of the engine, monitoring a series of pressure pulsations during a monitoring window duration via a pressure sensor positioned between a crankcase oil separator and the vent hose, and indicating a presence of degradation associated with the vent hose based on the series of pressure pulsations and the monitoring window duration. In this way, diagnosis of a state of the vent hose may be reliably assessed without crankcase pressures confounding pressure measurements as recorded via the pressure sensor.

Abstract: Particular embodiments of the inventive technology disclosed herein relate to the use of a dynamic valve to reduce motion caused by impulse force applied to a positioned component. Typically, the inventive technology finds application in an internally pressurized positioning system. At times, use of the inventive technology may lead to cost savings by, e.g., allowing for the use of smaller diameter positioner actuators and/or a reduced internal pressure.

Abstract: A guard for gas cylinder actuators, comprising a rigid or deformable covering element, to be fixed to the stem of the gas cylinder actuator with which it is associated or to the translating body against which the gas cylinder actuator is intended to act, the covering element being contoured so as to extend radially from the fixing region in order to protect the stem and the opening of the body of the actuator from which the stem exits.

Abstract: A compressed-air compressor for producing compressed air for a compressed-air system of a vehicle includes a cylinder and a piston. The piston is arranged in the cylinder and divides the interior space of the cylinder into a compression chamber, which can be connected to the compressed-air system of the vehicle for the purpose of conveying compressed air, and a neutral chamber. The neutral chamber is charged with an auxiliary pressure such that the pressure in the neutral chamber is temporally on average higher than atmospheric pressure. The compressed air production using the piston/cylinder-type compressed-air compressor is improved such that the maximum value of the torque to be imparted for driving the compressor is reduced.

Abstract: A four-chamber cylinder comprises a first piston device including a first piston and a first piston rod, the first piston delimiting a first chamber and a second chamber, a second piston device including a second piston and a second piston rod aligned with the first piston rod, the second piston delimiting a third chamber and a fourth chamber, and a compressive-elastic emergency element. The first piston, via the first chamber, and the second piston, via the fourth chamber, are configured to move towards each other and held with each other to tension the compressive-elastic emergency element. With the four-chamber cylinder according to the disclosure, an actuating movement is possible via the emergency spring even in the case of a supply failure, wherein the four-chamber cylinder can be installed and operated bi-directionally.

Abstract: An engine body includes a crankcase with a crank chamber therein, a cylinder block attached to the crankcase, and a breather passage which selectively permits fluid communication between the crank chamber and an area outside of the crank chamber. The engine body includes a one-way valve between the crank chamber and the breather passage, which allows a one-way flow of gases from the crank chamber to the breather passage. The one-way valve is pressure-operated and is operatively attached to a side wall of the engine body proximate a cylinder sleeve. The one-way valve may be mounted in a mounting window in a side wall of the crankcase, and a timing chamber may function as the breather passage. In an illustrative embodiment, the one-way valve includes a base plate having a valve hole formed therein, and a flexible reed valve plate with one end affixed to the base plate.

Abstract: A differential cylinder for a hydro-mechanical drive for actuating an electric switch, for example, a high-voltage switch, can include a first pressure area to be loaded with an operating pressure, a second pressure area, and a piston which can be moved in a movement range as a function of the pressure difference between the first and second pressure area. A damping device is provided which, during a movement of the piston in the direction of the second pressure area in one section of the movement range, provides damping against the movement of the piston, wherein the damping is adjustable.

Abstract: A motor/pump assembly for a motor vehicle brake system including a pump and a motor driving the pump, the pump having opposite working diaphragms which are, in each case, mounted between a pump casing and a cover and thereby delimit a space and which can be moved by a crank drive, the space being assigned, in each case, an inlet duct with an inlet valve and an outlet duct with an outlet valve. The outlet ducts are arranged in the covers and in the pump casing such that air displaced out of the spaces is conducted into an inner space surrounding the crank drive of the pump casing and that an air outlet unit be provided, which allows a low-noise blow-out of the air from the inner space as a result of the deflection of the air.

Abstract: A control device for a reservoir charging pump of a braking system of a vehicle includes: an actuating device designed to actuate the reservoir charging pump into at least one normal mode having a normal rotational speed, and a receiving device designed to receive a variable provided by a vehicle-specific component with respect to a supply voltage provided to the reservoir charging pump. The actuating device is additionally designed to ascertain whether the variable received lies outside a normal value range that is specified for the normal mode, and, if necessary, to actuate the reservoir charging pump from the normal mode into at least one deviation mode having at least one setpoint rotational speed deviating from the normal rotational speed.

Abstract: A pressure cylinder includes a pressure-boosting member set, an actuation member set, and a cylinder body, which defines two transversely extending air inlets, two transversely extending air outlets and two air passages respectively axially connected between the two air inlets and the two air outlets for allowing an applied compressed gas to flow through the two air inlets and the two air passages and the two air outlets into an air chamber in the cylinder body to move the pressure-boosting member set and the actuation member set in an oil accumulation chamber in the cylinder body. The hidden loop design for guiding the applied compressed gas does not require any extra pipelines and connectors, avoiding pipeline deterioration or connector loosening problems.

Abstract: A combined service brake and the stored-energy brake cylinder is provided, in which a ventilation valve which forms or shuts off a flow connection between the spring chamber and the service brake chamber of the brake cylinder ensures that disruptive noise is avoided while also preventing loss of air volume for building up the service brake force.

Abstract: An engine body includes a crankcase with a crank chamber therein, a cylinder block attached to the crankcase, and a breather passage which selectively permits fluid communication between the crank chamber and an area outside of the crank chamber. The engine body includes a one-way valve between the crank chamber and the breather passage, which allows a one-way flow of gases from the crank chamber to the breather passage. The one-way valve is pressure-operated and is operatively attached to a side wall of the engine body proximate a cylinder sleeve. The one-way valve may be mounted in a mounting window in a side wall of the crankcase, and a timing chamber may function as the breather passage. In an illustrative embodiment, the one-way valve includes a base plate having a valve hole formed therein, and a flexible reed valve plate with one end affixed to the base plate.

Abstract: A spring-return, pneumatic actuator includes a casing having therein a cylinder chamber, a housing chamber and a spring chamber and equipped therein with a piston reciprocating by air supplied and discharged from an air supply and exhaust vent on a primary side of the pistons. A piston rod is joined to the piston, and a conversion mechanism is provided for converting a reciprocating motion of the piston into a rotary motion. A spring undergoes a snap action due to the reciprocating motion of the piston, and a communication space chamber is formed via a communication part to have a predetermined volume from a secondary side to the spring chamber. The cylinder chamber has the piston and the piston rod built-in, the housing chamber has the conversion mechanism built-in and the spring chamber has the spring built-in.

Abstract: The compressor of the present invention has a structure in which a groove is disposed on a sealing surface of at least one of the head and the valve plate. The structure enhances contact pressure on a pressed surface, providing the gasket with preferable sealing strength. Besides, the head of the compressor has no protrusion on the edge. This eliminates worry about breakage of the head, providing high reliability and productivity.

Abstract: A hydraulic actuator has an armored section having concentric cylinders and an unarmored section having a cylinder with a frangible piston and a frangible upper gland nut. The hydraulic actuator may have leakage vents adapted to prevent leakage between hydraulic systems used to power the cylinders. The hydraulic actuator also may have a gland seal for sealing an end of the cylinder of the unarmored section and a sensing port adapted for allowing detection of fluid leaking due to damage of the gland seal.

Abstract: A combined service brake and spring-loaded brake cylinder includes an air-bleed valve having a piston supporting a valve body, which is guided inside a cylinder in an axially displaceable manner, and at least one first pressure spring supported on the piston being loaded against a first valve seat on the piston. The piston is loaded by at least one second pressure spring which is supported on the piston rod, in such a manner that the valve body is pushed toward a second valve seat on the piston rod and away from the first valve seat.

Abstract: A fluid dispensing apparatus having a) a compressed gas or CO2 cartridge controller, b) a hydraulic pressure medium connected to the CO2 cartridge controller, c) a flow control valve connected to the hydraulic pressure medium; and d) a hydraulic piston connected to the hydraulic pressure medium, whereby a CO2 cartridge applies pressure to the hydraulic pressure medium controlled by the CO2 cartridge controller, the flow control valve is operated to precisely meter hydraulic fluid to the hydraulic piston, and the hydraulic piston provides the linear force to dispense a fluid product with similar and matching regulation under pressure. A rotary valve can be provided to use spent CO2 to retract the piston.

Abstract: A variable compression ratio device of an internal combustion engine includes a piston inner part connected to a connecting rod and a piston outer part fitted on an outer periphery of the piston inner part. The piston outer part is only slidably in an axial direction, and is movable between a low compression ratio position near the piston inner part and a high compression ratio position near the combustion chamber. A skirt part is slidable and is guided by an inner peripheral surface of a cylinder bore of an engine. The skirt part is integrally formed on the piston inner part. A peripheral wall of the piston outer part is terminated directly above the skirt part. Thus, switching of the position between the low compression ratio position and the high compression ratio position by an inertia force of the piston outer part is performed smoothly with a reduction in weight of the piston.

Abstract: A non-pressure head for a fluid cylinder, which includes a drain channel formed in the flange by a raised portion of the flange extending from a plane of the flange in the same direction as the head portion. The channel is cold formed in the flange. For the piston stop, the flange has an opening of a diameter smaller than a diameter of a piston on the piston rod to form a stop for the piston. A plurality of spaced ribs are provided between the flange and the head. The ribs are raised portions of the flange and the head and are cold formed in the flange and the head.

Abstract: A pump (1) with an oscillating part having a housing (2) with a working chamber (3) and a crankcase (4) defined from the working chamber by the pump part. A pump drive mechanism (6) with a drive shaft (7) is located inside the crankcase (4) and the drive shaft is mounted on bearings (8, 9) that are arranged in the walls of the crankcase. The pump has a suction inlet separate from the crankcase. The pump (1) includes at least one flow channel in the crankcase wall for compensating pressure in the crankcase when the pump part oscillates and a flow damper arranged in the at least one flow channel. In a preferred embodiment, the at least one passage hole having at least one bearing therein is configured as the flow channel.

Abstract: An air-operated brake actuator system of a vehicle comprises a spring brake actuator and a service brake actuator, the spring brake actuator including a sealed housing with a spring chamber and a pressure chamber, and a hollow actuator rod disposed in the spring brake actuator and axially moveable for applying a parking brake, the service brake actuator including a service pressure chamber for applying a service brake, in which a control valve of the brake actuator system includes a valve body placeable within the hollow actuator rod, the valve body including an opening formed therein for allowing fluid communication between the spring chamber of the spring brake actuator and the service pressure chamber of the service brake actuator through the hollow actuator rod, the control valve including a membrane formed of an elastic material and having a breathing hole formed there-through, the membrane positioned within the opening of the valve body and configured to seal the opening except the breathing hole when t

Abstract: A spring brake actuator that utilizes a valve for providing compressed air to a spring cavity, the air having previously been dried and filtered so as to prevent contaminates and moisture from corroding and/or damaging the spring in the spring cavity, the valve being actuated by a difference in pressure from one side of the valve to the other.

Abstract: A hydropneumatic hybrid cylinder with tandem pistons and dampening hydraulic chambers disposed between them for combining pneumatically powered actuation with incompressible and controllable hydraulic dampening in order to achieve smooth displacement, rapid stopping and steady and accurate positioning of the cylinder in which hydraulic damping of a pneumatic actuator is achieved through utilizing positive-displacement hydraulic actuator means with zero volumetric differential.

Abstract: The invention is a bi-fluid actuator for precise bi-directional movement and positioning of a mechanical object or load. The bi-fluid actuator includes a pneumatic fluid container defining opposed first and second pneumatic fluid chambers, and having a first mechanical object secured between the chambers; a hydraulic fluid container defining opposed first and second hydraulic fluid chambers, and having a second mechanical object secured between the first and second hydraulic chambers; a pneumatic fluid controller; and, a hydraulic fluid controller. Directing pneumatic fluid into either the first or second pneumatic chambers, while controlling flow of hydraulic fluid between the first and second hydraulic chambers, controls movement and positioning of the mechanical objects which may be secured to a load.

Abstract: Guide for the piston rod of a piston-cylinder assembly, especially for a vibration damper, a shock-absorbing strut, or a level-control element, where the guide body holds the cylinder tube and the outside tube and simultaneously centers the piston rod in a central bore. The guide body has two axially spaced sealing elements which rest on the outside surface of the piston rod and seal off the interior space of the piston-cylinder assembly from the atmosphere. A flow connection, starting from the area of the intermediate space between the seals, extends to the interior space and is provided with a nonreturn valve, through which a flow can proceed only in the direction of the interior space.

Abstract: A sealed air-operated brake actuator comprising a brake actuator divided into a spring chamber and a pressure chamber. An extra-large force compression spring is contained in the spring chamber. The spring chamber is fluidly exhausted through a one-way valve located in the end of an actuator rod extending out of the brake actuator. The large force compression spring overcomes any vacuum or pressure that might form within the spring chamber upon the release of the parking brake and the one-way valve relieves any pressure buildup in the spring chamber upon the release of the parking brake.

Abstract: An actuator for use with a lift truck having an extendible mast includes an elongated housing and an axial bore formed in said housing. The bore has a first end and a second end. A ram is slidably and sealingly mounted in the bore for axial movement between an extended position and a retracted position, and has one end disposed in the bore and an opposing end extending out of the bore second end. A pressure ring is slidably and sealingly mounted in the bore between the ram one end and the bore second end, wherein filling the bore with a fluid causes the ram to move from the retracted position toward the extended position, and engagement of the ram one end with the pressure ring traps fluid between the pressure ring and the bore second end to resist movement of the ram toward the extended position. In a preferred embodiment the ram one end includes a piston plug body with an axial piston plug bore formed in the piston plug body.

Abstract: The invention relates to a hydraulic unit for a hydraulic control and/or regulating device, in particular for anti-blocking and/or anti-slipping brake systems, comprising control and regulating electronics arranged in a control housing as well as a valve block connected to said control housing, whereby at least one driving means is provided for at least one pressure-generating element. A cavity associated with the pressure-generating element receives leakage fluid from the pressure-generating element and a discharge channel that is connected to the cavity is provided in the valve block. According to the present invention, a means is associated with the discharge channel, and said means prevents fluid from entering into the discharge channel.

Abstract: A strap sealer has a dual action piston. A seal forming assembly is operably connected to the piston. The sealer includes a housing that defines a cylinder and has a penetration therein. A piston is disposed in the cylinder for reciprocating movement. The piston defines upper and lower pressure regions of the cylinder. The sealer includes a compressed air inlet, first and second flow paths between the inlet and the upper and lower pressure regions and a valve assembly for providing flow communication between the inlet to supply air to and exhaust air from the upper and lower pressure regions. A ram is mounted to the piston for reciprocating movement therewith. The ram traverses through the housing penetration. The ram has first and second cross-sectional areas that are different from each other. As the piston reciprocates, the ram traverses through the housing penetration.

Abstract: A pump housing, including a pump unit having a collection chamber that receives leaking brake fluid. In the installed position of the pump unit, an outflow bore leads downward from the collection chamber to the ambient air. A body which in one direction allows the outflow of leaking brake fluid and in another direction prevents the entry of splashing water and standing water is press-fitted into the outflow bore. The body comprises a porous sintered metal and on the ambient air side has a flat face end, while its face end toward the collection chamber is embodied in raised fashion.

Abstract: A brake system includes a pedal feel emulator and a master cylinder with a damping mechanism having a damping piston. When the emulator piston is moved from the at-rest position, fluid is displaced from the emulator through a compensation port and through a flow restrictive orifice in the damping piston to the reservoir. Flow rate of the fluid is dependent on the apply rate of the brake pedal. When the brake pedal is applied relatively slowly, sufficient flow volume will occur through the flow restrictive orifice and the damping piston will remain unmoved. As apply rates increase, a sufficient pressure differential will eventually be established across the damping piston to cause it to move. Damping piston movement compensates for rapid fluid displacement out of the variable chamber and enables a desirable pedal feel characteristic where pedal force increases relatively slowly as pedal velocity increases relatively rapidly.

Abstract: It is intended to dispense with the pipe welding work, thereby improve the pipe mounting performance and prevent contamination which results from welding, and elimination the waste of oil.A spigot portion 34 is mounted upright integrally in the center of the upper end portion of a piston 17, the base end of a piston rod 18 is fitted on the outer periphery of the spigot portion 34, and the outer periphery of the base end of a pipe 41 is press-fitted into an upper hollow part of the spigot portion 34.

Abstract: An improved plunger and barrel assembly is provided which includes a plunger reciprocally mounted in a cavity formed in the barrel and a leakage flow reduction device positioned in the cavity for reducing fluid leakage flow around the plunger thus increasing system efficiency. The leakage flow reduction device includes a sealing sleeve removably mounted in the cavity between the plunger and the barrel, which includes a bore for slidably receiving the plunger to form an annular clearance gap between the plunger and the bore. The sealing sleeve is designed to resiliently flex in response to fluid pressure forces to reduce the annular clearance gap so as to minimize fluid leakage through the annular clearance gap. The sealing sleeve is formed as a separate piece from the barrel to permit simple, low cost replacement. The sealing sleeve is preferably applied to a fuel pump having a pump plunger for pressurizing fuel in a high pressure chamber.

Abstract: A fluid-operated brake actuator having a check valve in the spring chamber to equalize the pressure on opposite sides of an operating movable diaphragm. The check valve being double redundant and tamper resistant and comprising a tubular body having a first one-way valve disposed and one end of the tubular body and a second one-way valve disposed at an opposite end of the tubular body. A support plate is mounted to the tubular body to support the second valve and prevents the easy removal of the check valve from the brake actuator.

Abstract: A downwardly opening compartment is disposed within a crank case. An upwardly disposed hole places the compartment in fluid communication with the environment. As blowby mist in the crank case travels upward through the compartment, the mist tends to separate into oil and air. The oil tends to drain back down into the crank case, and the air tends to continue upward and through the hole.

Abstract: A highly manufacturable gas compressor includes a sheath removably attached to a piston by several resilient fingers that snap into place at the bottom of the piston. The fingers act to limit relative motion between the piston and sheath as the piston is reciprocated within a cylinder bore. During the suction stroke of the compressor, the piston and sheath separate at their tops, creating an opening at the top of the sheath which allows low pressure gas to flow through an opening formed in the side of the sheath, between the sheath and piston, through the opening at the top of the sheath, and into a compression chamber formed between the top surfaces of the piston and sheath and the bottom surface of a discharge valve.

Abstract: A device including a first moving part such as a piston (1) and a second moving part such as a connecting rod (2) with a coupling part (4) therebetween. A low-pressure compressible liquid lubricant feed system delivers a liquid into a chamber (10) with a variable volume between the second part and the coupling part, to form a pump supplying the joint interstice (16) to be lubricated, by a one-way connection (13, 15) and a resilient return member (11), wherein the interstice communicates with a cavity (17) with a fixed volume used as a liquid lubricant source. The volume, in relation to the pump displacement, enables a degree of deflection of the pump piston (3) while achieving a sufficiently high pressure and compensating for leakage.

Abstract: A defined exhuast restriction in the form of an orifice or variable valve is provided to back-pressure the pulsating exhaust of an air motor or the like to reduce the formation of ice in the exhaust system.

Abstract: A brake actuator (10) for a vehicle comprises a service brake housing (14), a tandem spring brake housing (16) and a diaphragm (52), dividing the interior thereof into a first spring chamber (62) and a second spring chamber (63). In one embodiment, the first spring chamber (62) is completely sealed from the environment, being open only through a hollow actuator rod (56) connected to the diaphragm (52) and extending from the first spring brake chamber (62) into the service brake housing (14). A control valve (300) in the actuator rod (56) controls flow through the actuator rod (56) and is closed when the actuator rod (56) is retracted and also when the actuator rod (56) is extended to apply the brakes. The control valve (300) is open only as the diaphragm (52) and actuator rod (56) are moving.

Abstract: A piston reciprocally movable within a cylinder is sealed to the cylinder wall by fluid at a pressure greater than those of the fluids on the opposed sides of the piston supplied to the space (18) between two seals (19, 20) operative between the piston and cylinder wall, an accumulator or auxiliary intensifier chamber (67) being provided from which overpressure fluid is supplied to the space between the two seals to regulate the pressure between them. The two seals between the piston and the cylinder wall can be constituted respectively by first (19A-19C) and second (20A-20C) groups or pluralities of separate seal rings selected as regards material and dimensions so as to perform specific functions.

Abstract: An improved brake actuator is fully sealed against ingress of liquid or other contaminants. Separate breather tubes selectively communicate each of the pressure ports to the non-pressurized sides of the service and spring chambers. The separate breather tubes provide clean air into the non-pressurized chambers. Relief valves are positioned in each of the breather tubes. The pressurized ports may be reconfigured into two configurations such that the source of pressurized air may be connected to either of two orientations. In addition, a seal closely receives the push rod such that the non-pressurized chamber of the service side is fully sealed against ingress of liquids.

Abstract: A piston--piston ring assembly for an internal combustion engine reduces hydrocarbon emissions without significantly increasing the cost of the engine. The assembly includes an upper piston ring groove and a piston ring which acts as check valve to prevent combustion gases trapped below the upper piston ring from re-entering the combustion chamber when the exhaust valve is opened. The invention also includes a venting means for providing fluid flow communication between the crankcase side of the upper piston ring and the crankcase, around one or more lower piston rings, so that any trapped combustion gases are vented only in the downward direction toward the crankcase. The venting means includes a vent passageway slot in the lower piston groove, as well as an aperture adjacent to the lower piston ring groove.

Abstract: The fluid power cylinder possesses a housing, wherein a piston space is defined to accommodate a piston. In or on the housing a pressurized fluid receiver is arranged which possesses at least one receiver chamber connected with the piston space and which is supplied from a pressurized fluid source. Such a fluid power cylinder is characterized by reliable operation and good response behavior if it is run at a considerable distance from the pressurized fluid source.

Abstract: Unbalanced oscillatory pressures, developed on the power piston of hydraulic servoactuator systems cause vibrations on actuator housing supports. An unbalanced oscillatory force results, when two sides of the power piston are subjected to two unequal oscillatory forces induced by a disturbance. The two important disturbances are: pump flow rate oscillations, caused by power source torque oscillations; and, load oscillations. The invention is a hydraulic actuator connected in parallel to the power piston and designed to cancel vibrations by eliminating the unbalanced oscillatory pressure on the power piston. This is accomplished by designing the piston frequency of the invention, defined as tuning frequency, to be equal to the unbalanced oscillatory pressure frequency.

Abstract: An oilless reciprocating compressor for use in a refrigerated controlled atmosphere has an uncooled, fully sealed crankcase. A bypass tubing connects the interior of the crankcase with the inlet of the cylinders, so that blow-by is returned from the crankcase to the inlet of the cylinder for recirculation. In consequence no blow-by gas escapes into the controlled atmosphere. The device includes standard pistons, and has an improved cylinder head seal utilizing o-rings.

Abstract: A self-venting seal assembly for use in an ultrahigh-pressure pump is shown and described. In a preferred embodiment, a low-pressure seal is used to energize a high-pressure seal, the low-pressure seal having a "u" shaped cross-section, thereby creating a groove in a first end of the low-pressure seal. When the first end of the seal is exposed to pressurized fluid, it expands outwardly thereby substantially preventing the leakage of fluid past it. To the extent that any pressurized fluid does leak past the seal, which would act against a second end of the seal when the pressure on the opposite side of the seal drops, the seal compresses inwardly, thereby allowing the pressurized fluid to flow back past the seal.In a preferred embodiment, the high-pressure seal comprises a sleeve seal having an annular opening through which the plunger reciprocates, the sleeve seal being supported by a backup ring, the backup ring also having an annular opening through which the plunger passes.

Abstract: The invention relates to a hydraulic drive apparatus having a cylinder. Said cylinder comprises a piston movably mounted in a working chamber, a piston rod which is guided towards the outside through a cylinder head and a wear resistant primary seal and a leakage free secondary seal. Both said seals act between the cylinder head and the piston rod, with the primary seal being closer to the working chamber than the secondary seal. Further, a leakage oil conduit is provided between the primary seal and the secondary seal. Such a hydraulic drive apparatus is to be improved such that the cylinder will hold or maintain a load in a certain position even if the pump is switched off for a long period of time. This is achieved by providing that the leakage oil conduit can be subjected to the load holding pressure by switching a valve.

Abstract: This invention relates to reciprocating piston machines which use the crankcase for pumping air or charge. The connecting rod with extension partitions the interior of the crankcase including the lower cylinder into two varying volumes during a portion of each revolution of the crankshaft. A unique feature is that the designer can choose the capacity of the crankcase pump independent of other significant design parameters such as the ratio length of connecting rod/stroke and the ratio stroke/bore.

Abstract: A fluid-powered actuator (42) has a body (11) which includes an end wall (16) provided with a through-opening (21). A piston rod (44) has an inner portion (44A) arranged on one side of the end wall within a pressurizable working chamber (24) of the actuator, has a penetrant portion (44B) passing through the end wall opening, and has an outer portion (44C) arranged on the other side of the end wall. The rod is configured such that the transverse cross-sectional area of the penetrant portion is greater than the transverse cross-sectional area of the outer portion so as to define an annular surface (46) which faces away from the actuator chamber. The improvement provides a seal assembly (43) for containing fluid leaking from the actuator chamber.

Abstract: A vibration and noise free pump is disclosed. The pump includes a plurality of cylinders in radial arrangement about an axis. A piston is slidably supported in each of the cylinders. Each of the pistons has a vent opening in addition to a set of inlet openings to admit escape of liquid out of its piston inner chamber into a well with the piston in the compression stroke. With the provision of the vent opening, a surge pressure in each of the pistons has been reducedsed.