Abstract: A heavy duty diesel piston includes upper and lower portions joined across a friction weld and internally contoured to provide a dual gallery structure including an outer annular gallery and a central gallery joined by passages for communicating cooling oil therebetween. The dual-gallery structure allows oil to enter from the outer gallery, which is formed by the circumferential annular recess in the crown and crown bottom, into the central gallery to cool the piston and particularly the central crown region exposed to hot combustion gases. The friction weld provides high structural integrity and minimizes the number of manufacturing steps needed to attach the crown to the crown bottom.

Abstract: The invention relates to a cooled piston for internal combustion engines. The inventive piston is provided with an annular cooling channel on the periphery of the piston head. Said cooling channel, at its end that is open towards the piston shaft, is closed by a correspondingly shaped wall part that is radially split at least once. The aim of the invention is to improve the supply of cooling oil in the cooling channel. To this end, the wall part at the end allocated to the split is provided with a respective recess and with an upturned S-bend section that serves to deflect the cooling oil jet.

Abstract: Pistons for internal combustion engines often need additional cooling to attain better performance. One method of cooling involves adding oil to an oil gallery opposite a combustion zone. Adding a standpipe prevents a preestablished quantity of oil from exiting the oil gallery. Installing the standpipe intermediate a first baffle plate and a second baffle plate improves reliability of the piston and ease of manufacturing.

Abstract: A multi-part cooled piston for an internal combustion engine comprises a one-piece piston upper part having a combustion bowl and an annular wall with a piston-ring part, and a one-piece piston lower part having a box-like piston skirt, and bosses to receive the piston pins joining the piston to the connecting rod and boss supports, which are joined to the piston skirt. A cooling channel is formed through the piston upper part and also the piston lower part and is limited thereby in its cross section. A reduction of the compression height and an increase of the heat load can be achieved with this piston despite increasing engine power. The piston can also be assembled without microstructural change. The piston upper part and the piston lower part are provided with support elements having seating faces, which form a first and a second seat.

Abstract: The invention relates to a liquid-cooled piston (10) for internal combustion engines having a cooling duct (16) that has an annular shape or consists of several annular segments, said duct having a substantially constant cross section along its extension and extending in an undulated manner at least in certain areas in the direction of the axis of the piston (18).

Abstract: A closed gallery piston includes a piston body having a closed gallery for cooling oil defined in part by a bottom wall and outer wall of the piston body. At least one oil hole is formed in the bottom wall to accommodate a flow of cooling oil within the gallery. The bottom wall is locally thickened in the area bordering the oil hole with an oil hole boss to reinforce the bottom wall in the vicinity of the oil hole. The oil hole boss preferably joins with the outer wall to provide added structural integrity to the piston body at the juncture between the outer wall and bottom wall near the oil hole.

Abstract: A linear compressor includes a casing having a suction pipe and a discharge pipe and a unit including a cylinder formed therein and an inner stator assembly and an outer stator assembly installed on the exterior of the cylinder and a magnet assembly inserted into the certain void of the inner and outer stator assembly for performing a reciprocating motion linearly and a piston connected to the magnet assembly by forming a connection portion and a gas through hole formed in the connection portion of the magnet assembly and piston, which is capable of decreasing a flow resistance by forming the gas through holes in the connection portion of the magnet assembly and the piston and decreasing the specific volume of the suction coolant by making the coolant gas filled the both area of the connection portion flow reciprocally in the reciprocating motion of the piston.

Abstract: A heavy duty diesel piston includes upper and lower portions joined across a friction weld and internally contoured to provide a dual gallery structure including an outer annular gallery and a central gallery joined by passages for communicating cooling oil therebetween. The dual-gallery structure allows oil to enter from the outer gallery, which is formed by the circumferential annular recess in the crown and crown bottom, into the central gallery to cool the piston and particularly the central crown region exposed to hot combustion gases. The friction weld provides high structural integrity and minimizes the number of manufacturing steps need to attach the crown to the crown bottom.

Abstract: The invention relates to a liquid-cooled piston (10) for internal combustion engines having a cooling duct (16) that has an annular shape or consists of several annular segments, said duct having a substantially constant cross section along its extension and extending in an undulated manner at least in certain areas in the direction of the axis of the piston (18).

Abstract: The invention relates to a process for producing a cooling channel piston, in which the overall height is reduced in that the annular recess has a lower height than the height of the tool used for producing the cooling channel, and the production of the cooling channels starts parallel to the piston boss face, in which the axial height of the annular recess (8) is smaller than the axial height of the cooling channel (13).

Abstract: The invention aims at reducing the weight of a box piston having a running surface, the width in the pressure side is different from the width of the running surface on the counterpressure side. To this end, the piston has at least one bent channel that is cast using bent sleeves and is located at least partly above the bolt hubs with a tapering cross section extending approximately in the direction of pressure-counterpressure.

Abstract: A piston for an internal combustion engine, comprising a piston head (2) and at least one cooling chamber (4) that can be supplied with oil and is arranged underneath the head (2) of the piston, whereby the lower limit of the cooling chamber is formed by a sheet of metal that can be elastically deformed and is fixed to the piston. The objective of the invention is to enable the metal sheet (6) to be fixed in a simple manner. This is achieved by using components that are subjected to pressure, pressing the elastically deformable sheet of metal (6) against projections that are located at a height corresponding to approximately half way up the hub supports in the direction of the piston head (2).

Abstract: Pistons for internal combustion engines often need additional cooling to attain better performance. One method of cooling involves adding oil to an oil gallery on bowl portion opposite a combustion zone. Adding a standpipe prevents oil from exiting immediately exiting the oil gallery. Installing the standpipe intermediate a first baffle plate and a second baffle plate improves reliability of the piston and ease of manufacturing.

Abstract: In a piston and connecting rod assembly, for an internal combustion engine with a spherical connecting rod small-end entrained in a hollow piston body by a retention ring, a chamber serving as a localized reservoir for lubricant and/or coolant (oil) is incorporated in the underside of a piston crown along with passages or grooves communicating between the reservoir and a coolant gallery in the piston crown for continuous interchange of lubricant (such as oil) between gallery and reservoir and then lubricant return, over small end (upper and lower) part-spherical bearing surfaces to the retention ring and through lubricant passages in the ring to an engine crankcase, thereby affording an overall circulatory, lubricant feed and drainage path.

Abstract: A one piece piston for an internal combustion engine has a piston skirt that is connected to a flange portion and a supporting portion of a piston body. The piston skirt provides support to the flange portion and a piston ring belt portion disposed about and connected to the piston body. The one piece piston has a closed piston cooling gallery defined by the piston body, the flange portion and piston ring belt portion.

Abstract: A piston for a swash plate type compressor, including a head portion slidably fitted in a cylinder bore formed in a cylinder block of the compressor, a neck portion slidably engaging a swash plate of the compressor, and a connecting portion connecting the head and neck portions, wherein the head portion has an inner surface which faces towards a centerline of the piston and which has at least one recess formed therein. Each recess is configured so as to accommodate a liquid when the piston is fitted in the cylinder bore.

Abstract: A piston (10) particularly suited for heavy duty diesel engine applications includes upper and lower crown sections (28, 30) joined by a friction weld (32) to define an annular ring belt (14) formed with ring groves (22) and having a lower end (20) and an internal piston cooling chamber (34). A pair of pin bosses (40) depend from the ring belt (14) and are formed as one piece with the lower crown section (30). A skirt (46) is also formed as one piece with the pin bosses (40) and has an upper end (48) that is spaced from the lower end (20) of the ring belt (14) to define a space (52) therebetween which effectively uncouples the skirt (46) from the ring belt (14).

Abstract: A one-piece piston comprises a piston crown made of steel and a bottom component made of forged steel, and a cooling channel that is formed by welding the crown and the bottom component of the piston together. The cooling channel is located radially behind the annular grooves. The crown and the bottom component of the piston jointly form a central cooling chamber whose lower limiting wall is forged as one piece with the bottom component of the piston. The welding seams joining the crown and the bottom component of the piston are friction welding seams. The piston provides for superior cooling of the crown of the piston and simplifies the production of the welding seams.

Abstract: A compact one piece piston for use in an internal combustion engine has a compression height (“CH”) of between 55 percent and 70 percent the piston diameter (“D”) and a closed piston cooling gallery defined by a piston ring belt welded at spaced locations to a piston body and to a flange portion of the piston body. The flange portion supports a second end of the piston ring belt and resists deflection of the piston ring belt. The closed piston cooling gallery is configured to promote heat transfer and piston cooling by facilitating shaking of a cooling fluid located within the closed piston cooling gallery during reciprocal piston movement. A piston skirt extending from the flange provides additional strength and rigidity.

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 bottom surface and a support surface. And, a skirt member defines an upper outer support surface and an upper inner support surface. 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 bottom surface and the upper outer support surface and the interface of the support surface and the upper inner support surface respectively by a welding process. The force of combustion acting on the crown portion is resisted by the upper outer support surface being in contacting relationship with the bottom surface.

Abstract: For being slidably inserted into a cylinder bore defined by a cylindrical surface extending in a predetermined direction, a piston (8) has a head portion (81) extending perpendicular to the predetermined direction and a barrel portion (82) connected to the head portion. The head portion has an outer circumferential portion which is close to the cylindrical surface when the piston is inserted in the cylinder bore. The barrel portion has at least three wall portions (82a, 82b, 82c) which are extended from the outer circumferential portion in the predetermined direction. The wall portions are arranged in a circumferential direction to form a substantially cylindrical shape in cooperation with one another.

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 top surface. 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 by an inertia welding process. 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. Thus, the skirt member structure supports and resists the bending moment of the combustion forces on the head member.

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: A piston for a high performance engine has a crown and a skirt integrally formed with the crown. A step is defined about the crown and an annular channel is machined in the step. A ring belt facially encircling the crown sealingly covers the annular channel so as to form an enclosed passageway where the coolant circulates. The piston has passages by which coolant under pressure is sent to the crown. The crown has a coolant entry duct communicating the passages to the annular channel and has a coolant exit duct communicating the annular channel with a cavity in the skirt.

Abstract: A liquid-cooled internal combustion engine piston (10) comprises on the one hand at least one annular segment-shaped coolant duct (12a, 12b) formed within an upper piston member and having openings (16a, 16b, 18) at sites symmetrical relative to the gudgeon pin axis (14) for supplying and discharging oil. On the other hand, an approximately radial communicating duct (20) enclosed in its course toward the crank chamber and connected to the annular segmented ducts (12a, 12b) in the region of the openings (16a, 16b, 18) is provided.

Abstract: An articulated piston for use in heavy duty diesel engines including a piston crown having an outer surface, a peripheral pending side wall and an inner surface having a pair of pin bosses extending downwardly from the inner surface with the inner surface and the pin bosses defining a hollow cooling cavity opening downwardly and extending about a circumference of the piston crown and a piston skirt with the piston skirt including a first longitudinal plane containing a pair of diametrically opposed bores for receiving a wrist pin for connection to the bosses of the crown and defining two semi-cylindrical thrust and non thrust surfaces of the skirt with a thickness of the non thrust surface being less than a thickness of the thrust surface and a second longitudinal plane, perpendicular to the first plane thereby dividing the piston skirt into four peripheral quarters.

Abstract: An articulated piston for use in heavy duty diesel engines including a piston crown having an outer surface, a peripheral pending side wall and an inner surface having a pair of pin bosses extending downwardly from the inner surface with the inner surface and the pin bosses defining a hollow cooling cavity opening downwardly and extending about a circumference of the piston crown and a piston skirt with the piston skirt including a first longitudinal plane containing a pair of diametrically opposed bores for receiving a wrist pin for connection to the bosses of the crown and defining two semi-cylindrical thrust and non thrust surfaces of the skirt with a thickness of the non thrust surface being less than a thickness of the thrust surface and a second longitudinal plane, perpendicular to the first plane thereby dividing the piston skirt into four peripheral quarters.

Abstract: The invention concerns a method of producing a one-part piston which, in the region of the piston ring zone, has a closed cooling duct and a recess between the piston ring zone and the box-shaped piston body. The method comprises the following steps: a piston blank is produced by a forging process; the annular recess is produced by machining, the axial height of the recess corresponding at least to the axial height of the cooling duct; the cooling duct, which is open at the bottom, is produced by machining; hub bores are formed and the outer contour of the piston is finished; and the cooling duct, which is open at the bottom, is closed by a two-part cover ring.

Abstract: An engine piston comprises a piston main body including a piston head, and a cooling oil gallery in a form of a metal pipe integrally inserted in the piston head by a casting process of the main body. The oil gallery has an intermediate segment curved like an arc of a circle under the top surface of the piston, and first and second extensions extending from both ends of the intermediate segment, respectively, in the downward direction away from the top of the piston along the axis of the piston. This engine piston design facilitates the production process of the piston and reduces the manufacturing cost.

Abstract: An internal combustion engine with at least one cooling oil injector arranged in the motor housing, and at least one reciprocating piston made of light metal. The piston head has a combustion space depression and a closed, ring-shaped cooling oil channel arranged thereon. The channel has an inlet opening and at least one outlet opening. A cooling oil injector rigidly joined with the engine housing injects a free jet of oil aligned slanted relative to the axis of the piston. The ring-shaped cooling oil channel is partly filled with cooling oil in the motor operation. The inlet opening has an edge stretched out long in the circumferential direction of the piston, which ends funnel-like in the zone of the inside wall of the piston skirt. The piston can accommodate high stresses since the length of the inlet opening disposed in the circumferential direction of the ring-shaped cooling oil channel is slightly shorter than the length required to directly collect the oil jet in all piston positions.

Abstract: A diesel engine piston, which exhibits high resistance to heat load, has a cooling cavity formed circumferentially around and outwardly of the outer periphery of a reentrant combustion chamber. A cooling liquid inlet passageway through which cooling liquid is supplied is provided in the piston body. The inside diameter of the cooling cavity is smaller adjacent to the top of the piston than adjacent to the bottom of the piston, and the cross-sectional area of the cooling cavity gradually increases from the bottom of the cooling cavity toward the top of the cooling cavity. A funnel wall, which projects downwardly toward the bottom of the piston, serves as the inlet of the cooling liquid inlet passageway. A distributing member, positioned within the cooling cavity directly above the outlet of the cooling liquid inlet passageway, splits the cooling liquid into two streams for passage in opposite directions through two segments of the cooling cavity.

Abstract: An articulated oil-cooled piston for internal combustion engine extending along a longitudinal axis and including a piston skirt, a piston head with bosses, annular ribs and a piston pin disposed within the bosses for connecting the piston skirt and a connecting rod to the piston head. The piston head includes a ring belt which defines an outer border of an annular cooling oil duct. The annular cooling oil duct has a downwardly-facing opening which is covered by an annular plate. The annular plate is radially divided into plate parts, which are radially inserted into slots formed near the bottom end of the ring belt. When fully installed, the plate parts are disposed within a common plane which is oriented perpendicular to the piston axis.

Abstract: A piston and ring assembly operative within a cylindrical bore wall to retain pressurized fluid to one side of the assembly, the piston having a crown and an annular side wall for movement along the bore wall.

Abstract: A cooled multi-component piston is provided in which the hollow annular space in the piston head for the cooling oil is closed off underneath. This is achieved with a sheet-metal ring with a collet which fits in a recess in the piston-ring wall, the sheet metal ring being biased via a retaining clip against the shaft bush.

Abstract: A space (32) is formed between an inner end of a fitting hole (31) formed in a piston (21) and a piston rod (22) and is positioned radially inside a sealing member (24). By circulating a cooling fluid through the space, the majority of heat which is transmitted to the piston rod (22) can be absorbed, preventing transmission of heat to the sealing member. The temperature of the sealing member is kept lower and its deterioration can be inhibited.

Abstract: A method for the manufacture of a cooled piston head in which the upper and lower portions of the piston head are made separately a metal plate is placed on the lower side of the upper portion; then the upper portion incorporating the metal plate is joined to the lower portion by friction welding. The metal plate is provided with a central hole for the passage of cooling oil onto the undercrown, and means of communication with a closed cooling chamber defined by a circumferential groove on the head upper portion and the peripheral outer surface of the metal plate.

Abstract: A piston for an internal combustion engine has a crown and peripheral wall to carry a piston ring. A support extends between the wall and a bearing housing to receive the connecting rod. A cylindrical support member also extends from the wall around the support to a skirt. The support member is radially inset from the wall and a cylindrical bearing member is located on its radially outer surface.

Abstract: The invention relates to a piston for an internal combustion engine. The piston has a longitudinally extending axis and ring grooves for receiving piston rings, and a separate piston head having a top and an annular cooling oil duct. A ring belt extends downwardly from the top of the piston head to define an outer border of the annular cooling oil duct and forms a first support facing in an axial direction. Bosses define an inner border of the annular cooling oil duct and form a second support facing in an opposite axial direction. The cooling oil duct has an opening and an annular plate supported on the first and second supports by spring tension. The annular plate closes the opening of the annular cooling oil duct to retain oil therein to cool the piston.

Abstract: An improved wobble piston for an air compressor. The piston has a head integrally connected to a connecting rod. The connecting rod has a free end for connection to a rotating eccentric. The piston head has an internal chamber. Openings are formed through the piston head into the chamber on opposite sides of the connecting rod in a plane perpendicular to the eccentric axis. The location of the chamber openings establishes a flow of cooling air through the chamber as the piston is reciprocated in a cylinder.

Abstract: Piston tops (1, 70), specially those provided with combustion chamber (2, 20) and ring zone (3, 30) have their cooling condition sensibly improved in such regions due to a better use of the cooling oil capacity by closing the cooling chamber (5, 50) and the region 2I under the combustion chamber by annular ring members (96, 13) in a resilient material, e.g., a polymeric material or, preferably a spring steel, which clamp under the cooling chamber (5, 50) and the region 2I with dimensional interference respectively with grooves (10, 100), notches (11, 110) and groove 15. Methods for the manufacture of such top portion having a reduced compression height are also described.

Abstract: A piston assembly for use in a piston cylinder of an engine is disclosed. The piston assembly includes a piston rod which connects the piston assembly to a crankshaft. The piston rod has a pin receiving opening at an upper end. A piston head having a transverse bore is connected to the piston rod. A piston pin is disposed through the pin receiving opening of the piston rod and the transverse bore of the piston head. The piston pin connects the piston head to the piston rod and has an axial bore. A piston skirt is connected to the piston head. The piston skirt has a transverse bore and an oil reservoir formed in the upper surface. At least one piston skirt pin is disposed through the piston pin axial bore and the transverse bore of the piston skirt to connect the piston skirt to the piston pin. This connects the piston skirt to the piston head. A fastening device secures the piston skirt pin in position within the piston skirt and the piston pin.

Abstract: An internal combustion engine having its cylinders tilted at an angle of less an than 90 degrees relative to a vertical axis is provided with a oil drain mechanism for drainign excess oil that collects when the engine stops. For this purpose, an oil drain hole, which communicates with an interior of the piston body to drain the lubricating oil, is formed in the inner wall of an oil ring groove in such a way as to be located below the center line of the piston body. Both ends of the oil drain hole are set lower than the lowest portion of a piston head. Therefore, it is possible to prevent lubricating oil from entering the combustion chamber when the engine stops, without providing a whirl-stop on piston rings.

Abstract: A piston for an internal combustion engine with a separate head and skirt which are joined by a piston pin. The ring belt extends downward from the head and terminates above the pin. The space between the lower edge of the ring belt and a section of the head defines a cooling oil ring space. The head is provided with bores which extend from the cooling oil ring space upward toward the top of the head.

Abstract: A piston for an internal combustion engine is described, the piston having a lower crown portion and an upper crown portion, the upper crown portion including a combustion bowl and a piston ring-groove belt of generally annular form depending from the outer periphery of the crown surface, the lower crown portion comprising a generally circular plate member having an upstanding ring on the upper surface thereof, the upper crown portion and the lower crown portion being joined together by retention means between the combustion bowl and the upstanding ring, and between co-operating spigot and socket means formed on the base of the combustion bowl and on the plate member, to prevent withdrawal by axial forces, and there being an oil cooling gallery defined between the upper crown portion and the lower crown portion.

Abstract: A cooling arrangement for a piston head of an internal combustion engine including a plurality of cooling channels built-in to the piston head. Cooling medium induction paths and draining paths are formed through the piston head for introducing and draining cooling medium into and from the cooling channels. A single cooling medium injection nozzle is disposed within the engine cylinder. The cooling medium injection nozzle is oriented to inject the cooling medium so that an axis of a jet flow of the cooling medium injected from the cooling medium injection nozzle is aligned with the axes of the cooling medium induction paths at different stroke positions of a piston during an engine revolution cycle.

Abstract: A two-piece piston composed of independent head and skirt portions, wherein the skirt portion is mounted by means of a wrist pin on bosses located on the lower end of members pending from the head portion, the head portion being provided with an annular recess between the combustion bowl and the ring zone, and the skirt provided with a tray on its upper end, the annular recess and the tray defining a semi-open cooling chamber. With the piston assembled, the lower end of the head portion below the ring zone and the upper end of the skirt portion, which constitutes the outer wall of the tray, define an oil baffle designed to prevent the cooling oil from flowing from the tray toward the space between the piston and the cylinder.

Abstract: A piston head block is provided with smaller exernal diameter at the portion where a cut-out for receiving a lubricant injection nozzle that remaining portion. With the smaller diameter, a clearance or gap is formed between the internal surface of an engine cylinder and the external surface of the smaller diameter portion. Therefore, during piston stroke, the smaller diameter portion, in which the lubricant injection nozzle receptacle cut-out is formed, becomes free from the transverse stress.

Abstract: In a two-piece piston with a head piece and a trunk hinged only over the piston pin, the annular space radially located inside the piston ring groove and open in the direction of the trunk is covered with a sheet metal wall part forming a cooling duct. The sheet metal wall part is held by a collar that extends from the outer annular wall of the head piece and is cramped around the sheet metal wall part. For optimally covering the annular space, the sheet metal wall part is radially divided into two parts.

Abstract: A piston structure includes protection of the peripheral edge portion of a lubricant injection nozzle receptacle cut-out. The piston structure employs mechanisms for reinforcing the peripheral edge portion of the cut-out to an extent that can avoid concentration of the stress and thus can avoid the formation of cracks.

Abstract: Present day diesel engines having aluminum piston assemblies are limited to combustion chamber pressures of approximately 12,410 kPa (1,800 psi) whereas the desire is to increase such pressures up to the 15,170 kPa (2,200 psi) range. To reach such levels the instant piston assembly includes a steel piston member having an upper cylindrical portion of a diameter "D" and a compression height "CH". The ratio of the compression height "CH" to the diameter "D" being within the range of from 60% to 45%. The piston member is preferably forged and subsequently machined to precisely controllable dimensions. Moreover, the piston assembly is preferably of the articulated type and includes a forged aluminum piston skirt connected to the piston member through a common wrist pin. Engine manufacturers are also demanding a smaller engine package size while retaining power output, improve fuel consumption and decreased emissions.