Abstract: A diesel engine piston has a body and a crown engaged to the body with three inertially welded struts. The body includes a base extending downward opposite the crown with pin bosses having pin bores and a skirt extending downward from the base.

Abstract: A liquid cooled piston of an internal combustion engine includes a piston lower part and piston upper part which has a combustion chamber recess. These piston components are supported via joining lands which are spaced apart radially and together form a dividing plane, and are joined together with a material-to-material fit. In order to receive piston rings, the piston upper part has a ring area and includes an annular cooling channel which extends into the piston lower part and is connected to an inner cooling space via connecting channels. The cooling channel is adjoined by recesses which are oriented in the direction of a piston head, are configured as a blind hole and widen conically starting from the cooling channel as far as a recess bottom. The recess bottom can be of a pronounced undulating enlarged surface or a finely undulating configuration.

Abstract: The invention relates to a die casting ring (1) internally fitted with radial teeth (11) to be engaged into matching seats (22) provided on a piston (2). This piston-ring assembly prevents mutual rotation or axial translation, in addition to ensuring an optimal seal against infiltration of liquid metal during the die casting process. When the ring has a cutout (10), it can be mounted accurately onto the piston because the teeth (11) allow the cutout to be positioned anywhere relative to the piston.

Abstract: A piston for an internal combustion engine has a piston head, a piston skirt, and a circumferential recess configured between the piston head and the piston skirt. The piston has a piston base body and a piston ring element. The piston base body has a crown region of a combustion bowl and the piston skirt. The piston ring element has a piston crown, a wall region of the combustion bowl, a circumferential top land, and a circumferential ring belt with ring grooves. The piston ring element has a circumferential cooling channel between the wall region of the combustion bowl and the ring belt, closed with a closure element. The piston base body and the piston ring element have a circumferential joining seam in the region of the combustion bowl, by way of which seam they are non-releasably connected with one another.

Abstract: A piston including a crown and a skirt extending generally axially away from the crown. The skirt includes a pair of opposed skirt panel portions and a band spaced away from the crown and extending generally around a perimeter of the piston. The piston further includes a pair of strut assemblies, each strut assembly including a pair of struts which converge in a radially outward direction. Each strut terminates at or adjacent to one of the panel portions.

Abstract: A single-piece piston body for an internal combustion engine includes a crown portion having a circumferential ring belt including an oil ring groove configured to accommodate an oil control ring and a skirt portion having a first skirt wall disposed on the major thrust side and a second skirt wall disposed on the minor thrust side of the piston, and two box walls that connect the skirt walls and which are set back with respect to the ring belt. A first plurality and a second plurality of axial drain passages extend from the oil ring groove to the bottom of the crown portion, the first and second pluralities of axial drain passages being substantially centered at opposite box sides of the piston and each plurality of axial drain passages spanning an arcuate portion of about 45-75 degrees.

Abstract: A two-part piston for an internal combustion engine has an upper part that has a pin having an outside thread on the underside of its piston crown, and has a lower part that has a crown part, onto which an expansion sleeve that can stretch elastically in the axial direction is formed, radially on the inside. A pin is introduced into the sleeve in order to screw the upper part to the lower part. The expansion sleeve is stretched in the axial direction. In order to improve its strength, the material of the expansion sleeve has a higher stretching limit as compared with the rest of the piston material. The increase in the stretching limit is achieved by permanent stretching of the expansion sleeve in the axial direction, by approximately 1% of its length.

Abstract: A piston assembly for an internal combustion engine is provided, including a piston and at least one insert. The piston includes an annular recess, a first surface, a ring belt and a skirt. The annular recess is located between the ring belt and the skirt. The insert may include a longitudinal portion and one or more opposing arms. The insert may be configured to be coupled with the piston. The arm(s) may extend laterally from the longitudinal portion and may be configured to abut the skirt, thereby orienting the insert relative to the piston. The insert may be disposed along the first surface, and aligned with the piston skirt such that the arms of the insert form a circumference about the piston skirt. The arms may at least partially enclose the annular recess at the piston skirt.

Abstract: Disclosed is a piston (1) for a combustion engine, comprising an annular grooved reinforcement (4) that is screwed onto an externally threaded (13) collar (12) located in the piston head area via an internal thread (19) which is mounted on the inside of the grooved reinforcement (4). The grooved reinforcement (4) blocks a recess (14) so as to form an annular, closed cooling duct (21). In order to provide the screwed connection between the collar (12) and the grooved reinforcement (4) with sufficient stability, a radially outward area of the collar (12) is equipped with a bend that points towards the hub. Furthermore, the collar (12) is embodied in an elastically resilient manner so as to bend in the direction of the piston head when the grooved reinforcement is screwed in, thus prestressing the screwed connection.

Abstract: A two-part piston for an internal combustion engine has a piston head and a piston skirt. The piston head has a piston crown on the underside of which at least two boss lands, each provided with a head boss and a head boss hole are connected. The piston skirt has at least two boss bodies, each provided with a skirt boss and a skirt boss hole. When the head and skirt are joined, the head boss holes and skirt boss holes are flush in relation to each other for accommodating a gudgeon pin. Each boss body has a recess in which the corresponding boss land is accommodated with the associated head boss so that the head boss hole and skirt boss hole are aligned flush relative to each other.

Abstract: A die cast aluminum piston for a reciprocating compressor. The piston is cast with no coring and thus includes no aperture in the as-cast piston for a wrist pin. The aperture for the wrist pin is subsequently formed in the wrist pin in a preselected location after casting. The wrist pin is formed of a preselected diameter. Because the wrist pin can be placed in a preselected location with a preselected diameter, the same cast piston design can be used in a plurality of applications by varying the location of the aperture or the size of the aperture, or both.

Abstract: A monobloc piston assembly has at least two parts fixedly joined together forming a piston body having an oil cooling gallery. The oil cooling gallery is defined by an upper wall, a lower wall, and a pair of radially spaced inner and outer annular walls. A skirt is formed as one piece and of the same material with at least one of the two parts and depends generally along a longitudinal axis from the lower wall. A pair of pin bosses are spaced laterally from the longitudinal axis and depend generally from the lower wall. At least one elongated opening extends generally between the pin bosses with the opening preferably spanning a substantial portion of the distance between the pin bosses. Oil flows into and out of an oil cooling gallery through the opening.

Abstract: The invention relates to a piston comprising a shaft or supporting ring which rests directly on the hubs. The aim of the invention is to fix the latter on the hubs as simply as possible. To this end, the supporting ring is fixed on the hubs with a bayonet-type joint.

Abstract: A multipart cooled piston for an internal combustion engine comprises an upper part and a lower part of the piston. The two parts are screwed together via a threaded bolt that is arranged on the upper part of the piston, and a threaded bore that is drilled into the lower part of the piston. The threaded bore is arranged in an area of the lower part of the piston that is thin-walled to such a degree that it is deformed like a plate spring as the two parts of the piston are screwed together, so that no other safety means such as a lock nut are required for securing the assembled piston.

Abstract: A piston assembly for an internal combustion engine comprises a piston body having a head and a pair of pin bosses depending from the head having a pair of pin bores aligned along a pin bore axis. A piston skirt has a pair of opposed skirt portions and a pair of opposed side wall portions joining the skirt portions. At least one skirt retainer is supported on at least one of the side walls. The skirt retainer is biased axially inwardly along the pin bore axis in register with a corresponding one of the pin bores to connect the piston skirt to the pin bosses. The skirt connects with a snap-fit to the piston body.

Abstract: In a piston engine, end play of the piston pin can be prevented without unduly shortening the pin. In the simplest design (FIG. 4), a full length piston pin can have spherical end surface in close clearance spacing relative to the combustion chamber surface, so that any tendency of the pin to shift along the pin axis is immediately resisted by contact between a spherical end surface and the combustion chamber surface. The area of each spherical surface is sufficient to prevent wear or scratching of the combustion chamber surface. An alternative full length piston pin design incorporates spherical sheet-metal caps snapped in place at the ends (FIG. 2), which fix the pin (and caps) from coming into contact with the cylinder bore wall.

Abstract: A method of manufacturing a piston for heavy-duty diesel engine applications comprises forming a piston body having a pair of pin bosses, and bonding separately formed skirt portions to the pin bosses. The resultant piston has the separately formed skirt portions united to the piston body in a monobloc piston construction.

Abstract: In a piston engine, end play of the piston pin can be prevented without unduly shortening the pin. In the simplest design (FIG. 4), a full length piston pin can have spherical end surface in close clearance spacing relative to the combustion chamber surface, so that any tendency of the pin to shift along the pin axis is immediately resisted by contact between a spherical end surface and the combustion chamber surface. The area of each spherical surface is sufficient to prevent wear or scratching of the combustion chamber surface.

Abstract: A gudgeon pin (14) is held in engagement with a bearing seat situated inside a piston (16) by retaining means in the form of a pincer element (30) with a base portion (32) fixed to the end wall (20) of the piston (16) and with two pairs of resilient jaws (38) arranged on either side of the small end (12) of the connecting rod (10) and shaped so as to grasp the gudgeon pin (14) and hold it in the scat by a snap-coupling.

Abstract: In a piston-cylinder assembly with a shaftless piston, the aim is to improve the lateral guidance of the connecting rod, to reduce edge wear and the seizing tendency in the event of fault during the combustion process. Consequently, the piston has at least one supporting ring, form-fittingly on the bosses which guides in the cylinder the piston along with the piston head.

Abstract: A vacuum pump is provided with at least one cylinder having a cylinder liner and a piston mounted for reciprocating movement within the cylinder liner. The piston is connected to a crankshaft for reciprocating the piston and the piston is provided with a piston head having a flat face and an upper end thereof. A valve plate having a flat surface facing the flat surface of the piston head is biased into engagement with the end of the cylinder liner whereby upward movement of the piston the flat face of the piston head makes full contact with the flat face of the valve plate to move the valve plate away from the cylinder liner. The piston is provided with two annular lip seals having an L-shaped configuration disposed in opposite directions at opposite ends of the piston in engagement with the cylinder liner.

Abstract: A piston/cylinder assembly for a reciprocating compressor has a piston comprising telescopingly connected first and second piston members. The first piston member is connected to a connecting rod. The second piston member is provided with a piston head and is connected to the first piston member in such a way as to be movable axially relative to the first piston member by a predetermined distance. A spring is interposed between the first piston member and the second piston member to yieldably urge the first and second piston members axially apart.

Abstract: A piston for internal combustion engines with an inner piston eccentrically disposed inside the outer piston. The outer piston is attached to a journal at the top of the connecting rod by a wrist pin in the usual manner. The inner piston is attached by a wrist pin to a carrier slidably disposed within the slot of a forked lateral projection extending from the top of the connecting rod. Outer piston movement and inner piston movement relative to the outer piston, produces variable compression and applies torque to the crankshaft while at TDC (top-dead-center).

Abstract: An internal combustion engine includes a piston having a crown portion with a bottom surface and a skirt projecting therefrom to form a cavity, and a connecting rod having at one end a semicylindrical yoke portion with an upwardly directed semicylindrical concave surface and downwardly directed semicylindrical convex surfaces. A guide member is slidably retained between the bottom surface and the concave surface, and an annular member projecting into and fixed to the skirt defines spaced apart semicylindrical concave surfaces each engaging portions of the convex surfaces.

Abstract: An engine piston includes a piston head; a first bearing block forming a one-piece component with the piston head and having a first bearing face; a piston skirt being a component separate from the piston head; a second bearing block forming a one-piece component with the piston skirt and having a second bearing face; and a coupling device for interconnecting the piston head and the piston skirt and for interconnecting the first and second bearing blocks with one another. The first and second bearing faces complement one another to form a bearing for rotatably supporting a connecting rod.

Abstract: A piston for developing compression within the cylinder of a combustion engine or other type compression generating apparatus; said piston being a two-piece assembly, whereas the topside portion, or traditionally known as the crown, being of relative disc-shape in relation to asymetrics of said piston, is connected to the lower portion, or traditionally known as the skirt, by a distinct fastening means that consist of said crown being concaved from the underside and having multiple vertically positioned ridges that align the inside perimeter of said underside. Said skirt has another set of matching vertically positioned ridges that align the outer perimeter at the top of said skirt, as said top is appropriately sized to match said underside of said crown so that said crown may be press-fitted to said top of said skirt for a rigid and complete piston assembly.

Abstract: A groove in a direction of a crank shaft is provided in an inner surface of a top wall of a cup-shaped inner sleeve. The groove provides a stop for a semicylindrical slidable guide member that cooperates with a cylindrical concave portion of a cylindrical member to smoothly guide oscillation of a pair of arms at a small end portion of a connecting rod. Further, the slidable guide member allows relative sliding movement of the small end portion of the connecting rod in the direction of a crank shaft but inhibits relative rotation along the center axis of the piston.

Abstract: A piston connecting rod assembly has a floating piston pin that is retained in centered assembly by a retainer clip having hooked fingers that lock into grooves in one end of the piston bore and hooked stringers that lock the piston pin in position after installation. The clip is formed of any suitable resilient material such as glass filled thermoplastic.

Abstract: The design and construction of past piston assemblies having a wrist pin bolted to a connecting rod have excessive weight and structural components, and requires more complex machining techniques and tooling. The present invention overcomes these problem by providing a piston assembly (30) with a wrist pin (36) attached to a piston member (32). Thus, the length of the leg members (80) are short and do not require a portion surrounding the wrist pin (36). The results being reduced piston member (32) and piston assembly (30) weight and lower inertia, a simplified forging or casting process, a more easily machinable cavity (86) within the piston member (32) and a higher quality piston assembly (30).

Abstract: The design and construction of past piston assemblies having a wrist pin retained by a pair of snap rings positioned in a groove. Other past piston assemblies have a stubpin or cap positioned within a bore of a piston member or the wrist pin. In these applications the stubpin or cap is in continuous contact along the interface between the bore and the stubpin or cap. The present invention provides a device for retaining a wrist pin within a pair of bores of a piston member during operation of an engine. The device includes a shank portion having an outer portion thereon and only the outer portion of the shank portion being in contact with an inner surface of the wrist pin. The device and the wrist pin forming a wrist pin assembly. Thus, the device remains positioned within the inner surface and properly positioned the wrist pin assembly within the bores during operation of an engine within a bore of a cylinder liner.

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 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: 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 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. A depression is formed in the head and is partly defined by the section. The second land has the largest diameter and exclusively guides the piston. The height of the second land is in the range of three to seven percent of the piston diameter. The diametrical second land clearance is 1.5% to 2.5%. The diametrical third land clearance is one percent of the piston diameter. The diametrical top land clearance is in the range of 1.5 mm to 2.0 mm.

Abstract: A novel prefinished piston pin insert bearing is described wherein the tight radial clearances required for acceptable bearing function are maintained in spite of the tolerances required for assembly through a unique inner bearing surface geometry and through a unique methodology of bearing retention against axial and rotational movement. The interior bearing geometry is formed of radii equal to that of the piston pin which are offset vertically into the upper and lower bearings and of radii of nonspecific size which are offset horizontally. The bearings are retained against movement through connections with the piston head, the piston skirt, and between the various bearing pieces. Means are also provided for feeding oil under pressure to the piston pin and bearing interface for lubrication and to the piston assembly for cooling.

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.

Abstract: The pin assembly comprises a piston or crosshead connecting pin which has a throughgoing, axial hole formed therein which is tapped at one end to receive a headed fastener. Radial bores are formed in the connecting pin which bores open onto the axial hole and also onto the outer surface of the connecting pin. Locking pins are slidably disposed in the radial bores so that, as a headed fastener is threaded into the tapped end of the axial hole, the head of the fastener forces the locking pins to protrude from the radial bores and engage an annular groove, provided therefor, in the piston or crosshead.

Abstract: An impact tool including a cylinder, a piston slidably mounted in the cylinder and a valve for selectively opening and closing oil feed channels to move the piston up and down. A cylindrical member is slidably mounted on the piston around its large-diameter portion or thereunder. Its bottom end defines the top end of a lower chamber formed in the cylinder. The cylindrical member is adapted to descend together with the piston. But when the piston strikes the object and rebounds upwardly, the cylindrical member keeps descending away from the piston owing to the inertia force. Thus the volume of the lower chamber is kept from increasing excessively after the piston has struck the object. This will prevent cavitation in the lower chamber. When thereafter the lower chamber communicates with the oil feed port and pressure oil is fed thereinto, the cylindrical member will be pushed up toward the large-diameter portion under oil pressure in the lower chamber.

Abstract: A split piston in an internal combustion engine, having a base rockably secured to the connecting rod, and a detachable ring head which interfaces with the cylinder wall. The detachable ring head is snugly fitted onto a cylindrical extension of the base having an axis parallel to the cylinder walls, to allow removal on the head without removal of the engine crankshaft or connecting rod. The snug fit minimizes combustion gas losses and eliminates to need for gas tight seals, while allowing removal of the head. Threaded fasteners are used to secure the head to the base.

Abstract: In a compressor which has a connecting rod comprising: a second eye (31) connected to the crank pin (12) and a crankshaft (7) and including a radial projection (32) with a longitudinal slot (33), said longitudinal slot (33) having at least two end faces (35) and two opposite lateral faces (34);a first eye (21) connected to the piston and including a rod (22) with an end portion, said end portion having at least two end faces (25) and two opposite lateral faces (24), said end portion being fitted in said longitudinal slot (33) so as to bring the end faces of the slot (33) and the rod (22) into contact therefore defining the axial distance between the centers of the eyes.According to the invention a clamp (40) preferably of spring steel, is fitted in the housing (28, 29, 38, 39) of the radial projection (32) of the second eye (31) and the end portion of the rod (22).

Abstract: Pistons are described comprising a crown portion and a skirt portion, the crown portion having depending from the underside thereof a boss, the boss having secured thereto at least two bearing members in fixed relationship to the piston body and which bearing members co-operate with an associated connecting rod. The bearing members may be located in rebates in the boss such that piston firing loads are born substantially in compression. The bearing members are in one embodiment secured to the boss by a bolt and nut. The bearing members may comprise ferrous, copper-based or aluminium based alloys depending upon the application environment.

Abstract: A hydraulic cylinder, piston and rod assembly wherein the piston is secured to the rod in an efficient and inexpensive manner. The piston includes a threaded interior which is secured to a corresponding threaded portion on the end of the piston rod. An opening through a portion of the piston is aligned with a recess within the end portion of the piston rod to permit the insertion of a locking pin into the aligned openings. Thereafter, a compression ring, which is pivotally attached to the locking pin, is slipped into a complementary groove that is provided on the exterior periphery of the piston end portion. This provides a positive connection between the rod and piston which tolerates dimensional variations and eliminates play.

Abstract: Pistons are discribed comprising a crown portion which also includes a piston ring belt and gudgeon-pin bosses and which crown portion comprises a ferrous allow and a seperate articulated skirt portion comprising a casting of aluminum alloy, steel or cast iron which also includes gudgeon-pin bores, the crown portion and the skirt portion having a common gudgeon-pin about which the articulated skirt portion is freely able to move relative to the crown portion.

Abstract: Piston for combustion engines consisting of an upper part forming the piston crown and a lower part forming the piston body. These two piston parts abut via annular contact surfaces in the piston axial direction and are coupled together via a gudgeon pin or a gudgeon pin bushing. In order to arrange such an unscrewed piston in such manner that its upper part need not be constructed to be rigid and heavy as in an articulated piston with pendulum shaft and that the construction of cooling channels between the upper and lower parts is possible without excessive expenditure and the constructional height of the piston can be small, the contact surfaces are mutually prestressed in the direction of the piston axis in that the gudgeon pin bore in the one piston part is arranged to be offset relative to the gudgeon pin bore in the other piston part in the unstressed condition in the direction of the piston axis. In this connection, the offset can amount to 0.5 to 10 parts per thousand of the piston diameter.

Abstract: A crosshead piston 10 comprises a head member 18 and a skirt member 20, each of which can be secured independently to a piston pin 14. The skirt 20 has a reduced diameter upper end portion 66 which fits within lower end 24 of the head member ring belt portion 23, thereby exposing maximum head member surface area to a cylinder or cylinder sleeve wall for cooling. Preferably, the skirt end portion 66 defines a seal groove 32 which contains a metal ring 67 for sealing the gap 62 between the head member and skirt member.

Abstract: A multisectional piston for opposed-piston, slider-crank-drive internal combustion engines. The piston has a ceramic skirt (1), a skirt head (2), and a ceramic piston head (3) with fire land (4). The ceramic piston head is provided with annular groove (6) for receiving a slotted, ceramic piston ring (7) and is seated on the skirt head (2). A ceramic, common centering sleeve (5) fixes the skirt and head. Metal or metal alloy centering piece (8) fixed on the piston rod (12) in snug fit (14) has a base plate (9) on which the skirt head seats. An end cover (10) seats on the piston head and has a centering hub (11) axially spaced by a gap (23) from the centering piece. In assembly, the skirt head and piston head are axially clamped between the end cover and the base plate by a screw connection (13).

Abstract: The height of a piston for an internal combustion engine is reduced by the provision of gudgeon pin bores which intersect or at least partly intersect a ring band extending around the crown. This allows the mass of the piston to be reduced and allows improved visibility from the vehicle owing to reduced bonnet height. The weight of the piston is reduced so improving its performance and the performance of the engine.

Abstract: In a piston and connecting rod assembly for reciprocating piston machines the bending load applied to the piston pin bosses owing to the deformation of the piston pin to an oval shape should be prevented and the weight should be reduced. This is accomplished in that the piston pin is I-shaped in cross-section with wide flanges, the outer surfaces of which are shaped in accordance with an arc of a circle.

Abstract: A piston machine, particularly a hydraulically-actuated piston machine, comprises at least one cylinder having an axis, a piston axially slidable in the cylinder and having a piston bottom with an inner surface, a piston rod turnably connected with the piston and having a piston rod shaft, a turning member mounted on the piston rod and having a side which is opposite to the piston rod shaft and has a convex circular surface, a pressing member having a shell surface which is in sliding contact with the circular surface of the turning member, the pressing member having a side which is opposite to the turning member and is provided with a convex circular surface abutting against the inner surface of the piston bottom, the circular surface of the pressing member and one of the circular surfaces of the turning member and the shell surface of the pressing member having central axes with central axes projections along their common orthogonals forming an angle of approximately 90.degree..

Abstract: A multi-part plunger piston for internal combustion engines, comprises a piston upper part and lower part which engage one on the other through coinciding annular abutment surfaces. The parts are connected with one another by screws which pass through the annular surfaces. At least one of the annular abutment surfaces is domed in the circumferential direction in such a way that the annular surfaces are more strongly resiliently braced in the region between the screws in the finally assembled piston than in the regions around the screws. Due to the elastic initial stressing of the regions of the annular abutment surfaces between the screws it is intended reliably to avoid lifting away of the annular abutment surfaces in these regions during engine operation. When the finally assembled piston is in the cold condition the annular surfaces lie uniformly against one another over the entire circumference, admittedly with locally differing initial stresses.

Abstract: In a piston-cylinder assembly with a shaftless piston, the aim is to improve the lateral guidance of the connecting rod, to reduce edge wear and the seizing tendency in the event of fault during the combustion process. Consequently, the piston has at least one supporting ring, form-fittingly on the bosses which guides in the cylinder the piston along with the piston head.