Abstract: A piston device for internal combustion engines includes a first compression ring and a second compression ring in an outer circumference of a piston, wherein the second compression ring includes a notch extending from the inner circumference to the outer circumference on a lower surface of at least one of a pair of ends of the ring, and a gap between the ring ends at the notch on the second compression ring is larger than a gap between the ring ends of the first compression ring, and a gap between the ring ends at the section other than the notch on the second compression ring is the same or smaller than the gap between the ring ends of the first compression ring, and the second compression ring contains an outer circumferential surface comprised of a tapered surface decreasing the ring radial thickness towards the upper side, and an axial parallel surface formed below the tapered surface.

Abstract: This device is designed for a piston which is designed to move in alternating linear movement parallel to the axis of a chamber divided by the piston into a high pressure volume and a low pressure volume, and is of the type comprising: a circular cylindrical sliding surface bounding the chamber, an annular groove provided in the piston which is coaxial with the sliding surface and open towards the sliding surface, and a closed resilient sealing ring housed in a leak tight manner in the groove and intended to make sealing contact with the sliding surface. According to one aspect of the invention the ring is designed to determine the size of a lubricating oil film between the ring and the sliding surface to a limit lubricating thickness preferably from 0.1 ?m to 1 ?m when it moves from the high pressure volume to the low pressure volume.

Abstract: A seal for containment of fluids or gases during high temperature applications, separating a high pressure area on one side from a low pressure area on an opposite side, and formed to convert axial displacements into radial movements eliminating axial strains, having at least one engaging, conical ring structure with a tapering arcuate side facing radially away from the high pressure side. The conical ring structure has a side opposite the tapering side that is cylindrical, and a cylindrical diameter that is concentric with the arcuate side. The conical ring structure has an axial distal end with a larger diameter than its opposite end for engaging a flat annular surface on an adjacent structural member to form the seal. A heat-destructible wax spacer may be used for insertion within the clearance gap to locate the seal concentrically with the gland for ease of assembly.

Abstract: A nose seal for forming a fluid seal with a sealing surface in a bore The nose seal is particularly suitable for use in high pressure and high temperature conditions. The nose seal includes a substantially deformable sealing ring, which can form a resilient fluid seal with the sealing surface, and a substantially rigid ring, which prevents or limits extrusion of the substantially deformable sealing ring in high temperature and/or high pressure environments.

Abstract: A durable piston is applied in a cylinder of an engine to output internal exploding power and has a piston head and a durable ring unit. The piston head is mounted in the cylinder of the engine, is driven for outputting kinetic energy and has a ring unit mount. The durable ring unit is mounted around the ring unit mount and has a distal ring and a proximal ring. The rings are mounted around the ring unit mount. An inner edge of the distal ring and the proximal ring are separated from the piston head of the piston so forming a first airway and a second airway. When the engine operates, high-pressure air fills the airways and presses the rings against the cylinder. Consequently, the airways maintain contact between the durable ring unit and the cylinder tight to prevent air leakage.

Abstract: Various methods and devices are provided for use in a walking beam compressor used with an oil well pump. In general, an injectable fibrous sealant is provided for use in a stuffing box to form a seal around a piston rod that couples to a walking beam for pumping oil out of the ground. The injectable fibrous sealant can be configured to form a gas tight seal around the piston rod, while allow reciprocal longitudinal movement of the piston rod therethrough. The injectable fibrous sealant is particularly advantageous as it has an extended life, eliminating the need to replace the seal, and repairs can be performed on-site by injecting additional sealant into the stuffing box.

Abstract: The present invention provides a seal ring which can be prevented from being broken by an expansion and a shock applied thereto when the seal ring is fitted on a rotary shaft and does not have a configurative disadvantage such as a burr. Therefore no post-processing is required. The present invention also provides materials of the seal ring and a method of manufacturing the seal ring. The seal ring is made of resin and having two abutments confronting each other and a gate mark formed in an injection molding operation.

Abstract: The invention relates to an adjusting shaft arrangement (1) of a variable turbine geometry turbocharger or waste gate turbocharger having an adjusting shaft (2) which has a fastening section (3); having a lever (4) which is connected to the adjusting shaft (2) via the fastening section (3); having a sleeve (5) which is arranged on a base body (6) of the adjusting shaft (2); and having a seal (7) which is arranged in the region of the base body (6) between the sleeve (5) and the adjusting shaft (2); the main body (6) of the adjusting shaft (2) having a stepped outer contour; and the sleeve (5) having an inner contour with a stepped inner contour which complements the design of the base body (6).

Abstract: A purge gas introduction system for an orbital tube welding setup is provided, configured to inject high purity inert purge gas to the interior volume of a tube or tubular component. An o-ring is interposed between an annular base and an annular ring, their junction forming an annular o-ring groove, each part forming one sidewall, with the o-ring fully recessed within the groove, protecting the o-ring during the insertion and removal of a tube. The annular base and an annular ring are configured to receive a tube terminus. The sidewalls of the o-ring groove are divergent one to the other, wherein as the annular ring is drawn towards the annular base, the o-ring is forced partially out of the groove, forming a substantially leak tight seal between the tube and the o-ring. A purge gas from an external source is transmitted to the annular base through a purge connector, then, in turn, introduced to the interior volume of the tube.

Abstract: The present invention relates to a hydraulic system that includes a compression chamber capable of being subjected to the pressure of a hydraulic fluid; a piston movable inside the compression chamber along an axis; and at least one sealing gasket disposed between the piston and a wall of the compression chamber, the gasket occupying an axial position that varies circumferentially around the axis in such a manner as to compensate for non-axially symmetrical stresses induced by the pressure of the fluid.

Abstract: An oil ring for an internal combustion engine capable of securing an area of an oil-passing hole without deteriorating the strength of the oil ring. To achieve this the oil ring is provided with an oil-passing hole including: two arc portions disposed at both ends in circumferential direction, so as to be opposed to each other; two parallel straight portions disposed so that a widthwise direction distance therebetween is longer than a width of the arc portion; and inclined portions for connecting the arc portions and the parallel straight portions to each other.

Abstract: A flush valve handle assembly and a check valve assembly are provided for use in a flush valve, wherein the flush valve handle assembly and check valve assembly include improved components. The flush valve handle assembly includes a ball member and a plunger rod, one or both of which can be constructed of a polymeric material. An improved flush file retainer is provided which includes at least one ear integrally formed around a circumferential portion thereof. This at least one ear secures the flush file retainer in a snap-fit configuration in the socket-coupling. The check valve assembly includes a piston/seal having a plurality of ribs having a tapered design extending outwardly from a circumferential periphery of the piston/seal. The piston/seal includes a sealing material located on a top surface thereof. This sealing material can be a thermoplastic elastomeric coating material.

Abstract: A cup seal 21 includes a base portion 21a, an inner circumferential lip 21b slidingly contactable with a plunger 19 and an outer circumferential lip 21c contactable with the bottom surface 26a of the seal groove 26. Further, on the cup seal 21, there are provided elastic projections 21d projecting from the outer circumferential side leading end of the inner circumferential lip 21b toward the cylinder hole bottom portion. The length of the cup seal 21 from the base end face 21e to the leading end portions 21f is set longer than axial length of the seal groove 26. When the cup seal 21 is fitted into the seal groove 26, force is imparted on the inner circumferential lip 21b toward the cylinder hole inner circumferential direction to energize the inner circumferential lip 21b toward the piston all the time.

Abstract: A reciprocating engine 1 includes an annular top ring 5 serving as a first piston ring disposed adjacent to a top surface (head end surface) 4 of a piston 3 defining a combustion chamber 2; an annular second ring 6 serving as a second piston ring disposed with the top ring 5 interposed between the annular second ring 6 and the top surface 4; an annular gas chamber 7 defined by the top ring 5 and the second ring 6; and a plurality of communicating passages 8 for allowing the annular gas chamber 7 and the combustion chamber 2 to communicate with each other. The top ring 5 and the second ring 6 are respectively inclined with respect to an X direction in which the piston 3 reciprocates, so as to be located further away from each other on a thrust side 9 than on an anti-thrust side 10.

Abstract: The fluid machine with radial cylinders comprises cylinders (9) fixed with respect to the body (20) wherein the cylinders are peripherally spaced in the rotation plane of a crank (2) rotating with a driving shaft (1) of the machine; elements (12) distributing the fluid; it comprises, moreover, a piston (4, 34) of each cylinder placed in contact with the surface of said crank by means of sliding means (3, 39) and arranged within a jacket (6) of the cylinder with contact of the side (23), or side surface, of the piston in a restricted guide and seal area (7); for the guide function an annular edge (22) is present projecting from the inner surface of the jacket; for the sealing function a sealing ring (25) is present close to the guide edge on the jacket and housed in an annular slot (24) associated with the guide edge; elements (5) are also present for maintaining the contact between the pistons and the crank

Abstract: A piston ring includes a piston ring body and a surface coating film formed on at least one of upper and lower surfaces of the piston ring body. The surface coating film comprises a heat-resistant resin and a metal powder contained in the heat-resistant resin, and a phosphate coating film is formed, as base coating film of the surface coating film, on a surface on which the surface coating film of the piston ring body is formed.

Abstract: A large-bore (at least 180 mm diameter) diesel engine cylinder configuration featuring a piston crown bowl having an acute re-entrant angle and, optionally, an anti-polish ring. The acute re-entrant angle crown bowl involves a maximum radius of the crown bowl exceeding a minimum crown bowl radius, wherein the maximum crown bowl radius is located farther from the squish face than is the minimum crown bowl radius. The acute re-entrant angle crown bowl applied to large-bore, medium-speed diesel engines yields an improvement in performance and emissions characteristics. The anti-polish ring may be integrally formed with the cylinder liner and used in any internal combustion engine.

Abstract: A piston 1 contains multiple ring grooves 2, 3 on the outer circumference of the piston 1, and piston rings 4, 10 are mounted in the ring grooves 2, 3. The piston 1 contains oil path grooves 7, 9 extending respectively to the outer circumference of the piston 1 on the upper and lower surfaces of the lowermost ring groove 2, and an oil path groove 12 extending to the outer circumference of the piston 1 on the lower surface of the ring groove 3 just above the lowermost ring groove 2. The weight of the lowermost piston ring 4 is equal to or smaller than the weight of the piston ring 10 just above the lowermost piston ring 4; and expanders 5, 11 are installed on the rear side of the piston rings 4, 10 respectively.

Abstract: A piston ring assembly for an internal combustion engine is provided. The piston ring assembly includes a plurality of seal rings, i.e., a first seal ring and a second seal ring. The seal rings are positioned on at least a portion of a piston crown periphery axially and radially adjacent to each other within the internal combustion engine and at least a portion of the first seal ring at least partially extends over at least a portion of the second seal ring.

Abstract: A fuel injector tip seal is provided including improved resistance to the heat and pressures of combustion gas. According to one aspect, the tip seal is formed from polytetrafluoroethylene and between 10 and 35 percent carbon fiber. The material offers improved surface finish and deformation resistance as well as improved thermal conduction and keeps thermal expansion low as compared to conventional fuel injector tip seal designs. According to a further aspect, a revised seal groove design is provided that allows for expansion and deformation of the tip seal and creates more pressure to the outside diameter face when pressure is applied at the tip. According to another aspect, the tip seal is formed of a flat disk-shaped seal body that can be assembled on the fuel injector by an assembly cone device that allows the disk-shaped seal body to be flipped to a ring-shaped configuration in its assembled position.

Abstract: A method of installing annular seals on a plunger. A first step involves positioning an annular seal on a seal installation tool adapted to hold the annular seal in an expanded state. A second step involves positioning the annular seal so that the annular seal overlies a body of a plunger. A third step involves transferring the annular seal from the seal installation tool to a seal groove in the body of the plunger.

Abstract: Apparatus and method for providing a sealing member with enhanced hoop strength. In some embodiments, a valve assembly includes a piston and first means for establishing a fluid-tight seal when the piston is in a closed position and for preventing a blow out condition when the piston is transitioned to an open position. In other embodiments, a sealing member is characterized as an endless annular ring which extends about a central axis, the sealing member comprising an elongated circle cross-sectional shape while the sealing member is maintained in an uncompressed state. In other embodiments, a method comprises extruding a sealing material through an extrusion assembly to form an endless annular ring which extends about a central axis, the extrusion assembly imparting a desired amount of curvilinearity along a longitudinal length of the material to form an orthogonal seam when a leading and trailing edge of the material are adjoined.

Abstract: There is provided a sliding member including a base body and a hard carbon coating formed on the base body to define a sliding surface for sliding contact with an opposing member under lubrication according to one embodiment of the present invention. The hard carbon coating has an outermost surface portion lower in hydrogen content than a remaining portion thereof, or an outermost coating layer lower in hydrogen content than at least one other coating layer.

Abstract: A composite piston unit (10) for an automatic vehicle transmission, in particular a double clutch transmission, comprises a shift rod and a control piston provided at each end of the shift rod and designed to run in a respective cylinder, wherein each control piston comprises a carrier and an elastomeric sealing element bonded to the periphery of the carrier thus forming a composite system. Each control piston is securely connected with respectively one end of the shift rod and is designed to have an axial extent of less than 0.25 relative to its diameter.

Abstract: A power piston sealing assembly in conjunction with a Stirling engine is disclosed. The power piston sealing assembly consists of one or several sealing retainers with threads alternatively using fasteners within the power piston. Said power piston sealing assembly comprises of a power piston, displacer rod seal(s), displacer seal spring(s) and sealing retainer(s) all concentrically mounted within the power piston.

Abstract: A split displacer piston assembly (1) in conjunction with a Stirling engine is disclosed. Said assembly comprises of two main parts, displacer dome (8) and displacer base (9). Within the displacer dome there are several heat shields (10). The displacer base has a piston ring assembly (12) installed in an outer perimeter groove and fixed between the displacer base and displacer dome is a displacer guide ring (11). In order to service and or replace these parts rapidly, the displacer dome and displacer base are fastened by threaded engagement.

Abstract: A rod sealing system for use with a hydraulic cylinder is disclosed. The hydraulic cylinder has a cylinder tube and a cylinder head defining a working chamber. A piston is disposed for linear reciprocable movement within the working chamber and is connected to a piston rod projecting outwardly through the cylinder head. The rod sealing system includes a primary seal acting between the cylinder head and the piston rod and a secondary seal acting between the cylinder head and the piston rod. The rod sealing system also includes a back-up seal acting between the cylinder head and the piston rod and the cylinder head has a bypass channel fluidically connecting the working chamber with a chamber in the cylinder head between the back-up seal and the primary seal. Flow of hydraulic fluid through the bypass channel is selectively allowed or prevented with a bypass valve to selectively equalize the pressure across said back-up seal when the back-up seal is not in service.

Abstract: The present invention relates to a method for manufacturing a piston ring (10) for internal combustion engines, having the following method steps:—machining of a metal strip (20), with the result that it acquires at least one beveled face (15, 16) which represents at least one part of a ring flank of the piston ring (10) which is to be manufactured,—formation of a piston ring (10) from the metal strip (20) which has been machined in this way and the surface of which forms an inner and an outer circumferential face (11, 12) and an upper and a lower ring flank,—hardening of the surface of the piston ring (10). Furthermore, the present invention relates to a piston ring (10) for internal combustion engines, the surface of which forms an inner and an outer circumferential face (11, 12) and an upper and a lower rink flank, wherein the surface is provided with a uniformly thick hardened layer (21).

Abstract: An oil ring, particularly disposed in an oil ring outer-groove of a piston in an internal combustion engine or an air compressor, comprising a base ring (2) having a split, and an annular flange (1) radially-protruding outwards and disposed on outer circumferential surface of the base ring (2).

Abstract: For incremental sealing performance and cost reduction, a piston comprises a piston main body (1) and a seal ring (2), the seal ring (2) comprises a metal ring (21) including a fitting tube portion (21a) fitted to a cylinder portion (12) of the piston main body (1) and a flange portion (21b) extending radially oppose axially to a pressure receiving portion (11) of the piston main body (1), and a rubber-like seal main body (22) provided on the metal ring (21), and the seal main body (22) has a first seal lip (221) contacting to an inner surface of a clutch cylinder (3), a second seal lip (222) extending from an end of the flange portion (21b) to contact with the pressure receiving portion (11) and an axial direction compression seal portion (223) provided on the flange portion (21b) and compressed toward the pressure receiving portion (11)

Abstract: To prevent effects of small amplitude oscillations caused by pressure fluctuation, eccentric attachment of a cancel plate and biased load application of a return spring, and to achieve a long service life of the inner peripheral seal portion, a BPS (1) with a piston member (20) moving in an axial direction inside a cylinder (10) and defining a compression chamber (M) together with the cylinder (10) and a cancel plate (30) opposing to a bottom portion (11) of the cylinder (10) beyond the piston member (20) is provided with an inner peripheral seal portion (50) with a seal lip (52) slidably contacting an inner peripheral tube portion (13) of the cylinder (10) and a fitting portion (53) fitted to the inner peripheral tube portion (13) in an inner peripheral end portion (35) of the cancel plate (30).

Abstract: A piston ring assembly includes an upper ring, a lower ring and an expander disposed between the upper and lower rings. When assembled, the piston ring assembly is positioned with a groove of a piston. During down stroke of the piston, the upper and lower rings radially compress. This radial compression induces axial expansion of the expander, thereby urging the upper and lower rings against upper and lower surfaces of the groove. The piston ring assembly provides a seal between not only an outer periphery and a wall of a cylinder, but also between the piston ring assembly and the annular groove of the piston to prevent escape of oil and gases.

Abstract: A piston ring is positioned in a groove of a piston and has an outer peripheral face. The outer peripheral face is generally tapered to an edge and includes a projection. The projection extends radially outwardly from the outer peripheral face along an upper surface of the piston ring. The projection reduces the gap between the outer peripheral face and a wall of the surrounding cylinder. The gap is typically exposed to combustion gases and the projection reduces the exposed area. Ring collapse is the separation of the outer peripheral face from the wall of the cylinder because of downward pressure forces of the combustion gases. Accordingly, the projection reduces the occurrence of ring collapse.

Abstract: A sealing system for two components which can be moved in relation to one another, in particular for a piston which can be moved in a cylinder chamber or for a piston rod, is disclosed. The sealing system has two or more moving seals. An ionic liquid is arranged between at least two of the moving seals.

Abstract: A pressure reducer includes a piston slidably accommodated in a cylinder to define a decompression chamber and a pressure adjusting chamber. A seal member includes an elastic member and a sliding portion. The sliding portion is pressed by the elastic member such that the sliding portion slides on an inner circumferential surface of the cylinder. An annular member is located on an outer circumferential surface of the piston and between the seal member and the pressure adjusting surface. The annular member is pressed against the inner circumferential surface of the cylinder with a force that is less than a force with which the sliding portion is pressed against the inner circumferential surface of the cylinder. Thus, the pressure reducer prevents the piston from being moved by an excessive amount with highly accurately adjusting pressure.

Abstract: The invention relates to an oil scraper ring for pistons of internal combustion engines. The oil scraper ring comprises a disc that is provided with parallel flanks and a bearing surface having an asymmetrical crowned form with a vertex line extending over the periphery of the disc. A bracing spring arranged in a ring groove of the piston and comprising a spring groove side opposing the piston head and a spring groove side facing the piston head presses the disc radially against the friction and the abrasion of the bearing surface.

Abstract: A combined oil ring 1 is comprised of an oil ring 2 with a generally I-shaped cross section including upper and lower rails 6, 7 joined by a web 8 for sliding on an inner circumferential surface 10 of a cylinder 9, and a coil expander 3 to press the oil ring 2 radially outwards. The combined oil ring 1 contains a seal member 14 for sealing a gap of the oil ring 2 and capable of making contact with the upper rail 6 in an outer circumferential groove 12 formed by the web 8 and the upper and lower rails 6, 7. The seal member 14 may include a structure where the edge of the seal member 14 is bent, and catches in a window hole 13 formed on the web 8 of the oil ring 2.

Abstract: The present invention provides a seal assembly for sealing between two relatively slideable members of non-circular cross-section. A plurality of adjacent seal members may be staggered and grouped within a groove so that all leakage surfaces between the two relatively slideable members are sealed. Multiple seal members or seal member groups may be used to reduce leakage caused by incomplete contact of the seal members with leakage surfaces. An actuator system may comprise various embodiments of the present invention to enable the actuation of one member in relation to another.

Abstract: A piston ring assembly includes a piston ring formed of a shape memory alloy. By using a shape memory alloy material, the piston ring changes its shape during exposure to transient thermal conditions so as to minimize engine wear. The shape memory alloy composition of the piston ring is selected to exhibit a martensite phase during cold start operating conditions and as the temperature increases changes to the austenite phase so as to recover its original shape.

Abstract: A slip joint sealing device for use in piping systems, and particularly in reactor pressure vessels, seals the slip joint between two adjacent pipe surfaces using one or more piston rings positioned in a circumferential groove machined into the outer surface of an inner positioned pipe at the slip joint, and an optional circumferential spring may be employed to retain the piston ring in contact with the inner surface of the adjacent pipe at the slip joint.

Abstract: Valve with heated sealing gas suitable for use in a regenerative thermal oxidizer, and oxidizer including the switching valve. The valve of the present invention exhibits excellent sealing characteristics and minimizes wear. In a preferred embodiment, the valve utilizes hot gas from the regenerative process to heat gas for sealing the valve, and sealing air flows through a heat exchanger that is positioned to be in contact with hot exhaust gas from the regenerative process.

Abstract: A hydraulic accumulator includes a piston (3) capable of moving in an accumulator housing (1) in its axial direction and separating a gas side (5) from a liquid side (7) of the accumulator housing (1). Guide elements (9, 17) designed to co-operate with the accumulator housing wall (1), as well as at least one sealing element (15), are arranged at the periphery of the piston. The sealing element is arranged offset in the axial direction relative to the guide elements (9, 17), and is located between the guide elements. In the piston (3), a pressure compensating channel (19) forms, at the piston periphery, a liquid flow path between the liquid side (7) and a space (2) located between the guide element (17) nearest to the liquid side (7) and the sealing element immediately next in the axial direction. A device (25) reducing the cross-section of the passage of the pressure compensating channel (19) is located in it.

Abstract: A multipart oil wiping ring for pistons of internal combustion engines comprises two steel strip-type lamellae with parallel sides, the running surfaces of which are provided with a convexly asymmetric shape having a vertex line that extends across the circumference of the lamellae, and a bracing spring located between the lamellae. The bracing spring presses the lamellae in an axial direction against one respective side of an annular groove in the piston and in a radial direction against the cylinder wall.

Abstract: The invention relates to an oil scraper ring for pistons of internal combustion engines, said oil scraper ring comprising a disc (1) provided with a bearing surface (h) having an asymmetrical crowned form with a vertex line (3) extending over the periphery of the disc. Said disk (1) is arranged in a ring groove (7) of the piston and respectively has a ring groove side (6) opposing the piston head and a parallel ring groove side (5) facing the piston head. The aim of the invention is to achieve an improved oil scraping action compared to that of prior art, while reducing the friction and the abrasion of the bearing surface.

Abstract: In a corner portion (2) defined between an outer peripheral surface (4) and a lower-side surface (3) of a steel piston ring (1), a groove (5, 6) having either an approximately quadrangular shape with a length of one side of 0.05 to 0.4 mm or an approximately quarter circular shape having a radius of 0.05 to 0.4 mm is formed. A sharp edge (9) formed by the groove (5, 6) performs an oil scraping function and the groove (5, 6) works to reduce an oil pressure of a second land or a third land clearance between the cylinder bore and the piston.

Abstract: A seal assembly for use in an engine, such as a scramjet engine, having a movable element, such as inlet cowl flap, is provided. The movable element has an outboard structural member which requires thermal protection. The seal assembly includes a sealing element and a support block for thermally isolating the outboard structural member and for supporting the sealing element. In a preferred embodiment, the sealing element comprises a rope seal having a tadpole construction.

Abstract: A sealing arrangement on piston rods with a rod guided in a cylindrical compressed-gas space, particularly on piston rods of high-pressure pneumatic springs or gas-filled shock absorbers, with at least one seal disposed on the piston rod for sealing the compressed-gas space toward the outside, with a guide for the piston rod and with a lubricant space. The lubricant space is provided with an insert that is capable of absorbing the lubricant in sponge-like fashion.

Abstract: A piston ring including at least one intermetallic alloy is provided. A piston ring having a wear-resistant composite composition and a piston ring coating comprising a wear-resistant composition are also provided.

Abstract: A combined oil ring 4 is comprised of an oil ring 5 having upper and lower rails 7 and 8, and an expander 6 for applying contact pressure radially outwards on the oil ring 5. The outer circumferential surface 11 of the upper rail 7 of the oil ring 5 is comprised of a flat surface 11a with an axial width of 0.05 to 0.3 millimeters, a curved surface 11b joining to the upper end of the flat surface 11a and to the upper surface 12 of the upper rail 7, and a curved surface 11c joining to the lower end of the flat surface 11a and to the lower surface 13 of the upper rail 7. The lower rail 8 is formed in the same way.

Abstract: The invention discloses a piston ring comprising a piston ring substrate. The piston ring substrate comprises at least 50 volume %, of at least one intermetallic alloy, based on the total volume of the wear-resistant composition. The invention further relates to a piston ring comprising a wear-resistant composite composition and a piston ring coating comprising a wear-resistant composition, the wear-resistant composite composition comprising a ceramic compound.