Abstract: A working cylinder has a cylinder tube has closure parts arranged at tube ends. The cylinder tube and the closure parts define a cylinder interior. The cylinder has a coupling section that has one of the closure parts, a cylinder tube end and a hollow adapter body. The closure part has an external thread and the adapter body has an internal thread that define a common threaded section constructed to releasably couple the closure part and the adapter body. The cylinder tube end is connected to the adapter body on a cylinder tube side thereof by a ring weld seam. The weld seam defines a sealing plane sealed with respect to a pressure media. The piston unit defines at least one working chamber inside the cylinder.

Abstract: A method for producing a piston for an internal combustion engine may include producing a piston upper part including a piston top, at least parts of a ring section, and at least part of a cooling channel, producing a piston lower part and closing the part of the cooling channel arranged in the piston upper part via an additive method, and finish-machining the piston. Finish-machining the piston may include producing at least one annular groove in a ring support for receiving a piston ring.

Abstract: An exemplary system and method for welding a piston assembly includes a piston assembly having a cooling gallery and a loose granulated medium positioned therein. The cooling gallery is formed by a piston body and a cooling gallery ring, and a welder such as a laser welder is positioned proximate the assembly to weld the piston body to the cooling gallery ring. During welding, the assembly is rotated and the loose granulated medium is caused to remain in a gravitationally low portion of the cooling gallery. The weld is formed in an area proximate the loose granulated medium such that weld spatter emitted during welding is emitted into the loose granulated medium.

Abstract: A piston has a piston body extending along a central axis. The piston body has an upper crown portion and a lower crown portion. The upper crown portion has an upper combustion wall and an at least one annular upper rib depending from the upper combustion wall to a free end. The lower crown portion has at least one annular lower rib extending to a free end that is fixed to the at least one upper rib and an inner gallery floor extending radially inwardly relative to the at least one lower rib. The upper crown portion has an upper post depending from the upper combustion wall along the central axis to a free end. The lower crown portion has a lower post extending upwardly from the inner gallery floor along the central axis to a free end. Together, the upper post and the lower post form a labyrinth passage.

Abstract: A method for producing a one-piece, lightweight piston consisting of steel and having a small compression depth (S) forms piston with at least one cavity in a shaft aperture region. A piston blank is produced in a first step using a forging or casting method. To form a cooling channel between an annular region and a combustion chamber recess an annular section is formed in one piece onto the wall of a cooling channel in the vicinity of the piston base. The joint produced between the annular section and an outer wall of the cooling channel is sealed by welding.

Abstract: A piston for an internal combustion engine has a lower piston part and an upper piston part that are connected with one another by friction welding and form an outer circumferential cooling channel. The upper piston part has a circumferential ring belt provided with ring grooves, the inner wall of which delimits the circumferential outer cooling channel. An outer circumferential friction-weld seam is provided below the ring belt, the width of which seam is less than or equal to the wall thickness between the groove root of the ring grooves and the inner wall of the ring belt.

Abstract: A method of friction welding a piston includes forming a piston body by friction welding an upper crown portion to a lower crown portion. At least one of the upper or lower crown portions is provided with a central support post extending along a central axis. The upper and lower crown portions have annular ribs radially outwardly from the central support post, with the ribs being aligned with one another. The method includes initiating a friction weld joint between a free end of the central support post and a corresponding surface opposite the free end of the central support post. Then, after initiating the weld joint between the central support post and the opposite surface, the method continues by then initiating a friction weld joint between aligned free ends of the ribs. Then, the friction weld joints are completed.

Abstract: An axial piston intended for an axial piston machine and comprised of at least two components forming a driving part and a compressing part. To enable manufacture of the axial piston in an easy and inexpensive way while simultaneously reducing the weight, the components are manufactured by a solid forming process and joined together by a capacitor discharge welding process.

Abstract: A piston head is formed to have a bowl, micro chambers in the piston body adjacent to the bowl, and orifices providing communication between the micro chambers and the bowl. The micro chambers are formed in the piston head by using grooves that in part define the volume of the reaction chambers, and which are completely sealed from above with permanently secured plugs.

Abstract: An axial piston intended for an axial piston machine and comprised of at least two components forming a driving part and a compressing part. To enable manufacture of the axial piston in an easy and inexpensive way while simultaneously reducing the weight, the components are manufactured by a solid forming process and joined together by a capacitor discharge welding process.

Abstract: A method for producing a piston of an internal combustion engine, designed as a one-piece cooling channel piston. The piston includes an upper part and a lower part supported by corresponding circumferential joining bosses together forming a joining zone. In order to produce a bonded joint of the upper part and the lower part, the joining bosses are connected by means of multiorbital friction welding in the region of a rotationally symmetrical or rotationally asymmetrical joining zone.

Abstract: A piston for an internal combustion engine has a lower piston part and an upper piston part that are connected with one another by friction welding and form an outer circumferential cooling channel. The upper piston part has a circumferential ring belt provided with ring grooves, the inner wall of which delimits the circumferential outer cooling channel. An outer circumferential friction-weld seam is provided below the ring belt, the width of which seam is less than or equal to the wall thickness between the groove root of the ring grooves and the inner wall of the ring belt.

Abstract: A power assembly for an internal combustion engine includes a piston housed within a cylinder, with the cylinder having a welded cylinder head, with the cylinder also including a one-piece piston scraper which is welded to the cylinder head, as well as to the cylinder, with a common weld bead.

Abstract: The invention relates to an axial piston machine, in particular, an air-conditioning compressor for motor vehicles, with at least one piston, an essentially cylindrical piston shaft and an enclosure, which encloses a tilt ring or a tilt disc and a piston slipper sliding on said tilt ring or said tilt disc, whereby the enclosure has spherical recesses for housing the piston slipper.

Abstract: A laser-welded single-piece forged-steel piston with an enclosed inner oil cooling chamber having the advantages of simple structure and easy manufacturing process, and capable of satisfying the requirement of engines for high power, high rigidity, and low discharge development, and its manufacturing process. The laser-welded single-piece forged-steel piston of the invention comprises a piston body member and a piston ring member, wherein the piston body member is welded together with the piston ring member through laser welding procedure, an enclosed inner oil cooling chamber is formed between the piston body member and the piston ring member, and is connected with the piston inner cavity by means of at least two oil inlet/outlet holes, and a pin hole is opened at the lower portion of the piston body member.

Abstract: The invention relates to a method of producing a piston (1) with a combustion chamber recess (2) for an internal combustion engine, in which at least one region of the combustion chamber recess (2) comprising at least one recess base (20) is melt-treated in order to re-melt a material in the melt-treated region, so that a buildup of the material in the melt-treated region is changed in a layer with a definable depth, and relates to such a piston (1).

Abstract: The invention relates to a tubular piston for a piston engine, comprising a tubular section, a collar shaped region and a ball pivot formed thereon, and an inner tube arranged in an outer tube. A cavity is at least partially formed between the outer tube and the inner tube. Said cavity is sealed from the area surrounding the hollow piston in a pressure-tight manner, by a material, especially a solder material, which is arranged in the cavity in a positively locking manner by means of heating.

Abstract: The invention relates to a device with at least one extension arm or support arm for multi-linked crane shaped extension arms, concrete spreader columns and similar, comprising at least one hydraulic differential cylinder for actuating a support arm. The cylinder comprises a hollow piston rod which has a tubular segment and two end pieces arranged on the ends of said segment, whereby at least one of the end pieces is welded on to the segment thereof. The welded joint is machined and the root of the weld is eliminated. At least one of the end pieces comprises a through opening which enables tool access in order to machine the hollow cavity of the hollow piston rod.

Abstract: A hollow piston (1) piston engine including a closed annular cavity (9). Said hollow piston constituted of a first piston part (1a) with a base section (3) from which a joint part (4) extends in one axial direction, and from which a peripheral wall (6) that delimits the annular cavity (9) on the outside, and a mandrel (7) that delimits the annular cavity (9) on the inside extend, each as one piece, in the other axial direction. The hollow piston is also constituted of a second piston part (1b) having a cover (8) which is connected to the ends of the peripheral wall (6) and of the mandrel (7), said ends facing away from the base section (3). In order to achieve an economical and simple production while ensuring the provision of a stabile construction, the peripheral wall (6) and the mandrel (7) are formed on the base section (3) without machining.

Abstract: A closed cavity piston includes an elongated piston body and a separately formed piston cap having an elongated stem and head thereon. The body includes a closed end and an open end with a cavity having a bottom wall adjacent the closed end and an outer wall terminating in a rim at the open end. The stem of the piston cap is friction inertia welded to the bottom wall of the piston body and the head of the piston cap welds to the rim of the piston body so as cover the open end and sealingly enclose the cavity. The piston components can both be formed by conventional and relatively inexpensive cold forming techniques. The stem of the cap is inserted into the cavity of the body until it engages the bottom wall. Then the cap is friction inertia welded to the body at the stem/bottom wall and head/rim interfaces.

Abstract: The piston for a magneto-rheological fluid system is manufactured from a piston skirt of a material having a high magnetic permeability and a piston plate which closes one end of the piston skirt having a low magnetic permeability and therefore must be made out of a material such as stainless steel. The piston is manufactured by placing the plate on one electrode and clamping another set of electrodes against the outer circumferential surface of the piston ring or skirt. The plate and ring are brought into contact with one another while applying a current through the piston ring and the piston plate, thereby heating interfering portions of the ring and plate and permitting the plate to be forced inside of the ring while at the same time allowing the softened or plastic portions of the ring and plate to intermingle with one another and thus form a solid state bond.

Abstract: To enable economical production of a piston for a piston pump, the piston is made from a tubular deformed part and a closure plug, which is press-fitted with a protrusion into the deformed part. The piston has the advantage that the piston can be made without metal cutting in the form of deformed parts, for instance by extrusion, and hence can be produced quickly and economically.

Abstract: A hydraulic piston for a cylinder block of a hydrostatic power unit has an elongated cylindrical body with first and second ends. An elongated cavity is formed in the body. A cap is adhered to the body to close the cavity. The cap has an external shape to facilitate the operative engagement thereof with a slipper, which is in subsequent engagement with a swashplate mounted adjacent the cylinder block. The piston has an elongated first conduit formed in the body which is separate from the cavity and extends between the opposite ends thereof. The conduit terminates in registering communication with a second conduit in the cap thereof to permit transmission of oil through the conduit without invading the volume of the cavity. The cap preferably has a tapered surface on the inner end thereof engaging a compatible shaped surface on an adjacent end of the body to center and align the cap with the body.

Abstract: The piston for a magneto-rheological fluid system is manufactured from a piston skirt of a material having a high magnetic permeability and a piston plate which closes one end of the piston skirt having a low magnetic permeability and therefore must be made out of a material such as stainless steel. The piston is manufactured by placing the plate on one electrode and clamping another set of electrodes against the outer circumferential surface of the piston ring or skirt. The plate and ring are brought into contact with one another while applying a current through the piston ring and the piston plate, thereby heating interfering portions of the ring and plate and permitting the plate to be forced inside of the ring while at the same time allowing the softened or plastic portions of the ring and plate to intermingle with one another and thus form a solid state bond.

Abstract: There is provided a reciprocal motion type compressor which has a piston reciprocally movable in a cylinder. The piston has a piston cover and a piston body portion. The piston cover has an insertion portion engaged with the piston body portion. The insertion portion has a sectional shape which becomes smaller gradually from the cover portion toward an end surface of the insertion portion. This structure provides an increased tensile strength of the piston.

Abstract: A piston for use in the cylinder block of a hydraulic power unit. The piston has an elongated cylindrical body and one end terminating in a spherical surface. The piston is composed of a body and insert which are made from different materials, preferably metallic materials, and joined together. The piston body takes the form of a solid cylinder or a hollow cylindrical tube. The spherical surface takes the form of an internal spherical socket or an external spherical ball. The insert takes an elongated or abbreviated form providing for both open cavity and closed cavity piston configurations. The piston includes a conduit which traverses the body and insert, providing a path for pressurized fluid. The body and the insert are preferably formed by a metal injecting molding process utilizing a molding material comprised at the time of molding of a mixture of metallic grains and a binder.

Abstract: A closed cavity piston assembly includes a piston body, a separately formed piston cap sealingly joined to the body, and an elongated stem integrally formed with one of the piston body or the cap. In one embodiment, the stem is integrally formed with the piston body. In another embodiment, the stem is integrally formed with the piston cap and slidably journaled in and sealed to a hole in the bottom of the piston body. The cap of the piston assembly also has a surface for engaging a slipper. In either case, a fluid passageway extends through the stem, body, and cap of the piston assembly. The passageway is remote from the side wall of the piston body and fluidly isolated from the main interior cavity of the hollow piston body once the cap and body are sealingly joined together. The piston assembly can be pivotally attached to a slipper that has its own fluid passageway, which registers with the passageway in the cap, to provide fluid for slipper lubrication and balance.

Abstract: A hollow head portion of the piston is provided with a bottomed cylindrical portion and a cap closing an opening of the bottomed cylindrical portion. The cap is in the form of bottomed cylinder including a bottom wall, a cylindrical large diameter portion and a cylindrical small diameter portion. An outer circumferential surface of the small diameter portion is fitted to an inner circumferential surface of the cylinder portion of the bottomed cylindrical portion so that end faces are contacted with each other, and then these end faces are connected to each other by welding. A cap length, which is an axial distance from an apex surface of the cap to the end face thereof is set to be larger than a thickness of the bottom wall so that the welded portion is located far from a boundary portion between the bottom wall and the large diameter portion.

Abstract: A method of producing a hollow piston for a compressor, which includes a hollow cylindrical body member having an open end at at least one of its opposite ends, and a closure which closes the open end, the two members being welded together at respective welding surfaces, the method comprising the steps of: forming a first cutout in an outer surface of the cylindrical body member and a second cutout in an outer surface of the closure member, each of the first and second cutouts being located adjacent to a corresponding one of the welding surfaces of the two members, and extending in a circumferential direction of the cylindrical body member or the closure member along an edge of the corresponding welding surface, which edge is nearer to a corresponding one of the outer surfaces of the two members; fixing the two members together, so that the first and second cutouts define a groove having a bottom; and applying a welding beam to the bottom, so that the cylindrical body member and the closure member are bonded

Abstract: A piston for use in the cylinder block of a hydraulic power unit. The piston has an elongated cylindrical body and one end terminating in a spherical surface. The piston is composed of a body and insert which are made from different materials, preferably metallic materials, and joined together. The piston body takes the form of a solid cylinder or a hollow cylindrical tube. The spherical surface takes the form of an internal spherical socket or an external spherical ball. The insert takes an elongated or abbreviated form providing for both open cavity and closed cavity piston configurations. The piston includes a conduit which traverses the body and insert, providing a path for pressurized fluid.

Abstract: The present invention is a piston for use in an internal combustion engine and a method of manufacturing the piston. In the method of the present invention, a first block comprising a first alloy and a second block comprising a second alloy are press-forged to form a piston. The piston has a head and a skirt, with the head comprising at least a portion of the first alloy and the skirt comprising at least a portion of the second alloy. The first alloy preferably comprises an aluminum-iron based alloy, and the second alloy preferably comprises an aluminum-silicon based alloy. Preferably, during the forging process an interface between the blocks is increased in length or area, whereby oxide layers on the blocks are destroyed and the material comprising the two alloys is bonded directly.

Abstract: Past pistons have been susceptible to reduced longevity due to increased forces of combustion thereon during operating cycles of an engine. The present two piece unitary piston increases the longevity of pistons used with increased forces of combustion. For example, a head member has a crown portion defining a ring band portion having a bottom surface and a support portion. And, a skirt member defines a ring band support surface and a mating portion. The head member and the skirt member have a preestablished material strength being generally the same. The head member and the skirt member are joined at an interface of the support portion and the mating portion by an interference fit and are joined at the interface of the bottom surface and the ring band support surface by a weld. The force of combustion acting on the crown portion is resisted by the ring band support surface being in contacting relationship with the bottom surface.

Abstract: This invention relates to a piston and a method of manufacturing the same. The piston includes a substantially cylindrical member having a first end and a second end. The cylindrical member includes an open cavity extending axially from the second end to adjacent the first end such that the second end has an inner annular surface defined by an inner diameter. The piston further includes a disk having a radially outer surface defined by an outer diameter fixedly secured to the second end of the cylindrical member. The outer diameter of the disk is substantially equal to the inner diameter of the inner annular surface of the second end of the cylindrical member. A circumferentially extending recessed area for receiving particles produced while fixedly securing the disk to the second end of the cylindrical member is provided on either the radially outer surface of the disk or the inner annular surface of the second end of the cylindrical member.

Abstract: A two-piece, or articulated, piston head for internal combustion engines having top and pin boss portions in which the underside of the top portion is provided with a groove whose inner wall is eccentric in relation to the longitudinal axis; of the top and the upper side of the top portion is provided with a combustion bowl eccentric in relation to the top portion longitudinal axis and concentric with the inner wall of the groove on the underside of the top portion.

Abstract: A method to manufacture an articulated piston head wherein the two portions composing the head, i.e. the top portion and the pin boss portion, are formed separately from blanks of forged or cast chromium-molybdenum steel or a low alloy steel, subjected to preliminary machining operations, joined together by friction welding and then machined to final dimensions.

Abstract: A cooled piston head and method of manufacture, the piston head having a closed cooling chamber. In one embodiment, the piston head is formed of a top member, an intermediate member and a pin boss member joined to each other preferably by welding; the top and intermediate members are provided with circumferential grooves which defines the closed cooling chamber. In an alternate embodiment, the head is formed of a top member and a pin boss member joined together preferably by welding; the closed cooling chamber is defined by circumferential grooves provided on both members.

Abstract: Pistons and a method for their manufacture are described. The piston has at least one piston ring groove reinforcing member being annular in form and having, in cross-section, upper and lower, generally radially extending face portions and a radially inner, generally axially extending face portion between the two generally radially extending face portions, the generally axially extending face portion being coated with particulate material by a physical vapor deposition technique, to provide a porous adhesion assisting layer.

Abstract: Pistons and a method for making them are described. The pistons have reinforcing components, such as piston ring groove inserts, incorporated therein. The reinforcements have one or more porous bodies joined thereto, for example, by brazing and which are infiltrated during casting of the piston.

Abstract: A plastic piston of master cylinder has a first member having a small diameter portion and a second member having a large bore portion. Excess welding resin is prevented from being leaked into a seal ring mounting groove formed on a part of the outer peripheral surface of the small diameter portion by provision of welding portions in the form of a space defined between an outer peripheral surface of the small diameter portion of the first member and the large bore portion of the second member, and a gap defined between a tip end of the small diameter portion of the first member and the bottom of the large bore portion, the space and gap being provided respectively for preventing the excess welding resin from being leaked into the seal ring mounting groove. The plastic piston has no parting lines along the seal ring mounting groove which results in achieving a superior seal effect.

Abstract: Piston rod assembly includes a composite piston rod having an entrapment ridge along the length thereof, and a non-integral metallic piston head having two separate piston head sections which are welded together in preloaded engagement against opposite sides of the entrapment ridge. The entrapment ridge has oppositely facing external tapered ramp surfaces which are engaged by correspondingly tapered internal ramp surfaces on the respective piston head sections. When the piston head sections are initially brought into engagement with opposite sides of the entrapment ridge, there is a slight gap between the inner faces on the piston head sections which determines the amount of preload force that must be applied to the piston head sections to eliminate the gap and bring the inner faces into substantial mating engagement with each other for welding.

Abstract: A pump plunger formed from a centrally bored cylinder of a preferred compound having counterbored ends provided with inwardly converging counterbore inner end limits for thermally shrinking and centering a bolt and its nut therein. One end of the bolt projects beyond the cylinder and is threadedly connected axially with a plunger mounting shaft. The cylinder is turned concentric with the mounting shaft.

Abstract: An aluminum torpedo piston is provided with a piston head fabricated from a etal matrix composite material composed of aluminum and silicon carbide fibers that are integrally joined by an inertial welding technique. A 23% weight of silicon carbide fibers to powdered aluminum was selected. Resistance to intense heating which would otherwise cause melting and erosion of the piston is avoided to permit longer, high speed runs.

Abstract: A piston is formed in two parts. The main part is formed by gravity die casting from aluminum or aluminum alloy and a second part of the piston is formed by a squeeze casting process to produce a material which is stronger and more resistant than the gravity die cast aluminum or aluminum alloy. At least one piston ring groove is formed in the second part. The two parts are then electron beam welded together to form the complete piston. The squeeze cast portion may be reinforced with whiskers or fibres to further improve its properties. This method of construction has the benefit that only the minimum amount of the piston is formed by the more expensive and time-consuming squeeze casting process so that parts of the piston which do not require the improved properties given by squeeze casting are simply gravity die cast. This is of particular benefit in large diesel pistons.

Abstract: This invention discloses a thermally insulated piston having a cap portion and a body portion. The cap can be made of metal or ceramic. The cap and body portion are joined together by a brazing alloy. The cap portion can have a groove for receiving the brazing alloy. The ceramic cap can have a retaining band portion in a retaining band groove the band being bonded to the body portion by a brazing alloy. The piston with the ceramic cap can have an interlayer between the cap and body portion, the interlayer being bonded to the cap portion and body portion by a brazing alloy. The interlayer can have an outer knife edge. The body portion has a machined groove adjacent to the cap portion comprised of cells filled with thermal insulating material.

Abstract: In a cooled composite piston having a cooling passage adjacent to the interface and a method of making same, the upper part consists of forged steel and is formed on its underside with ribs bearing on mating surfaces of the lower part. To improve the resistance to thermal and mechanical stresses, the upper part has been welded by means of charge carrier rays to the lower part, which consists of cast ferrous material.

Abstract: This invention discloses a thermally insulated piston having a cap portion and a body portion. The cap can be made of metal or ceramic. The cap and body portion are joined together by a brazing alloy. The cap portion can have a groove for receiving the brazing alloy. The ceramic cap can have a retaining band portion in a retaining band groove the band being bonded to the body portion by a brazing alloy. The piston with the ceramic cap can have an interlayer between the cap and body portion, the interlayer being bonded to the cap portion and body portion by a brazing alloy. The interlayer can have an outer knife edge. The body portion has a machined groove adjacent to the cap portion comprised of cells filled with thermal insulating material.

Abstract: A piston is provided for an internal combustion engine, having a crown portion comprising an upper part and a lower or ring-bearing part which two parts are of different metals welded together. The two metals are chosen to have the same coefficient of expansion but the metal of the upper part of the piston crown is less heat-conductive while that of the ring-bearing part is highly heat-conductive. The piston has a cooling chamber formed in it, part of which chamber is adjacent the upper part of the piston crown while another part of the cooling chamber is adjacent the ring-bearing part.

Abstract: The present invention relates to an assembly, for use in a pressurized fluid mechanism equipped with pistons bearing against a reaction plate by way of slipper blocks, which assembly consists in such a piston and the associated slipper block coupled to one end of said piston by means of a "ball and socket" type assembly, the male element of the assembly being constituted by that part of the slipper block facing the face supporting the said slipper block on the reaction plate. A bolt comprising a screw and nut, joins the slipper block to the piston, the supporting surfaces of the nut and of the screw head on the corresponding parts of the slipper head and of the piston being of the "ball and socket" type.The invention finds an application in the production of high power hydraulic motors.

Abstract: A fluid cylinder assembly comprising a cylinder housing including a closed end portion and a piston assembly including an end piece member having at least one projection extending therefrom for abutting the closed end portion of the cylinder housing so as to prevent the piston assembly from completely engaging the closed end portion, a washer member having a projection extending therefrom and a cup member. The washer includes bulges on both sides thereof circumferentially spaced from the projection such that the bulges are disposed against the surfaces of the end piece member and cup member when the projection of the washer is inserted within the projection of the end piece member so as to allow fusing of the bulges with the end piece member and the cup member.

Abstract: A reciprocating fluid device is provided in which dynamic stresses in the weld between the cylindrical tube and the base thereof are reduced by prestressing the tube proximal to the weld prior to welding.