Abstract: A piston ring, having a base body, which comprises a substantially circumferential running surface, which has an upper and a lower flank surface, an inner circumferential surface, and a butt opening provided with defined butt clearance, wherein the transition of the running surface butt edge into the respective butt surface is configured as a sharp edge, and the running surface is provide with at least one PVD cover layer ?10 ?m at least up to the respective running surface butt edge.

Abstract: A piston ring, with a main body, which exhibits a contact surface, an upper and a lower side surface, and an inner circumferential surface, in which at least one of the side surfaces is provided at least with one PVD coating layer, to the effect that the layer thickness of the PVD coating layer tapers radially from the outside inward.

Abstract: The invention relates to a piston ring which is produced from a carrier material, especially steel or a cast material. The piston ring has a wear-resistant coating from a periodic multilayer system, every periodicity consisting of at least two individual metal nitride layers. The multilayer system has superlattice structures, the thickness of an individual layer being ?2 nm to <15 nm and the thickness of the multilayer system being >4.5 ?m and adjacent individual layers within the periodicity having different metallic elements.

Abstract: The invention relates to a piston ring, having a base body, which comprises a running surface provided with a chamber, an upper and a lower flank surface, and an inner circumferential surface, wherein at least the chamber is provided with at least one wear protection layer, and a PVD cover layer is applied to the running surface at least in some regions such that the base body has the PVD cover layer only in the edge regions, which is to say outside of the chamber, in the finished state.

Abstract: The invention relates to a piston ring which is produced from a carrier material, especially steel or a cast material. The piston ring has a wear-resistant coating from a periodic multilayer system, every periodicity consisting of at least two individual metal nitride layers. Adjacent individual layers within the periodicity have different metallic elements. The thickness of an individual layer is ?15 nm.

Abstract: A piston ring, having a base body, which comprises a substantially circumferential running surface, an upper and a lower flank surface, and an inner circumferential surface, wherein the transitional region of the running surface is provided with an edge ?0.1 mm in the lower flank surface, and the running surface is provided with at least one PVD cover layer ?10 ?m.

Abstract: The present invention relates to a piston ring for an internal combustion engine, the piston ring comprises a sulphide rich compound layer forming a surface layer, said sulphide rich compound layer comprising an iron nitride matrix with iron sulphide (FeS) inclusions embedded in said matrix, said sulphide rich compound layer having a sulphur content of 1 to 4 wt % S and a nitrogen content of 10 to 20 wt % N.

Abstract: A sliding member is characterized in that a sliding surface of the sliding member is coated with an amorphous hard carbon film, and a surface of the amorphous hard carbon film has a ten-point mean roughness of equal to or less than 0.7 micrometers and an initial wear height in a range of 0.07 to 0.14 micrometers.

Abstract: A piston ring for internal combustion engines with a coating of Chromium nitride (CrN) deposited by a physical vapor deposition process on a sliding surface with a typical crystal structure of CrN phase, has a high wear resistance and superior resistance to the generation of micro-cracks and consequent localized loss of pieces of the coating. The coating is a columnar crystalline coating of CrN having a dispersed pore content lower than 10% in volume and ratio of intensities, measured through x-ray diffraction, between the crystal planes (111) and planes (200), parallel to the surface, in the range of 0.40 to 0.70. This crystalline distribution is obtained through an oxygen content impregnated in the CrN coating between 1.0% in weight to 7.0% in weight. The Vickers hardness of the film ranges from 1,500 to 2,200 HV.

Abstract: A piston ring for an internal combustion engine is made of steel and has an outer contact surface that is nitrated and coated to no more than 70 ?m with a protective coating comprising nitrides of aluminum and/or silicium and/or zirconium in a matrix of chromium-nitride based material.

Abstract: A manufacturing method of a piston ring is developed, wherein the method provides a countermeasure for wear of butt ends of the ion plating film coated piston ring and a countermeasure for breakage of the piston ring and the piston ring manufactured at a low cost. A thickness of the film (2) in the vicinity of butt ends (7) of a piston ring (1) is made greater than the thickness of the film (2) at other outer peripheral surface. Piston ring blanks (5) are rotated around their own axes toward an evaporation source (4) and a speed is lowered when the butt ends (7) face the evaporation source (4).

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.

Abstract: A combination of piston and piston ring includes a piston having a piston ring groove in which at least the groove portion of the piston is made of steel, a piston ring made of cast iron and fitted into the piston ring groove, and a hard coat film formed to at least an outer peripheral sliding surface of the piston ring.

Abstract: Aggressive property of the nitrided side rails (30), which are combined with a spacer expander (31) to construct the oil-control ring, against the opposing material is improved. A nitriding layer consisting of nitrogen diffusion layer is formed on the outer peripheral surface or inner and outer peripheral surfaces of side-rail steel. The surface is free of compound layer. Hard grain-boundary phases (intergranular phases) are not present at least in the surface region of the side rail.

Abstract: A piston ring for use in a cylinder of an internal combustion engine, which ring is nitride-hardened at least on the sliding surface between piston ring and cylinder wall. The nitride layer is composed of a precipitated layer and a compound layer, wherein the piston ring consists of a low-alloyed iron-base material and an oxide layer is deposited on the compound layer.

Abstract: A piston ring having a stainless steel base material, the base material having an upper surface, a lower surface, an inner circumferential surface and an outer circumferential surface, the surfaces each having a nitride layer formed thereon, the nitride layer each first being formed to have a compound layer and a diffusion layer, the diffusion layer of the outer circumferential surface then being exposed by removing the compound layer of the outer circumferential surface, the exposed diffusion layer thereafter having an ion-plating deposition layer of hard ceramic formed thereon, the piston ring wherein the exposed diffusion layer is entirely removed on the upper and lower corners of the upper and lower surface and the outer circumferential surface by chamfering corner regions of the nitride layer located around the upper and lower corners before the ion-plating deposition layer is formed.

Abstract: According to an embodiment of the present invention a piston ring for internal combustion engines for use with a piston and a cylinder, is provided that has an external circumferential sliding surface adapted to slid against the internal wall of the cylinder. The piston ring has an ion-plating deposition layer formed over the externtal circumferential sliding surface, the deposition layer having pores and being made of a mixture of a first chromium nitride of CrN type and a second chromium nitride of Cr2N type. The mixing ratios in the mixture are more than 45.5 and less than 98.0 weight percent for the first chromium nitride and the balance portion for the second chromium nitride. According to another embodiment of the present invention, a piston ring for internal combustion engines for use with a piston and a cylinder, is provided that has an external circumferential sliding surface adapted to slid against the internal wall of the cylinder.

Abstract: A piston ring is made of martensitic stainless steel. Except for the outer circumferential surface of the piston ring, a nitrided layer having a Vickers hardness of 700 or more is formed on the upper and lower surfaces and inner circumferential surface, and a nitrided layer having a Vickers hardness of less than 700 is formed below the nitrided layer. A hard film is then formed by ion plating only on the outer circumferential surface of the piston ring. The hard film formed by ion plating and the nitrided layer with a Vickers hardness of 700 or more are separated without making contact in the vicinity of at least one of corner sections formed by the upper and lower surfaces and outer circumferential surface. The distance is within a range of 0.001 to 0.3 mm. The nitrided layers can be formed just on the upper and lower surfaces of the piston ring.

Abstract: An improved sliding member is provided that has a sliding surface and a deposition layer formed on the sliding surface utilizing an ion-plating method, wherein the deposition layer is composed mainly of chrome nitride, including CrN. The CrN of the chrome nitride has a preferred orientation of plane {111} and contains boron in an amount of not less than 0.05 and not more than 20 weight percent. The deposition layer further contains oxygen and/or carbon in an amount of not more than 15 weight percent. The improved sliding member exhibits excellent abrasion and scuff resistance and enhanced peeling resistance.

Abstract: A piston ring for use in a piston of an internal combustion engine comprises a base material of a first hardness formed into a ring, and a secondary material of a second hardness formed by selective and superficial heat treatment of an outer portion of the base material. At least one outer surface of the ring is selectively and superficially heat treated in one of a variety of ways to form an austenitic metal layer about 100 &mgr;m thick on the surface of the ring. The ring is then rapidly cooled in an appropriate environment, resulting in the transformation of the austenitic compound into a martensitic compound adjacent the base material at the point of heat treatment. Preferably, the martensitic metal has a hardness range of 800 to 1000 HV (Vickers Hardness scale) measured at a load of 100 grams.

Abstract: According to a first embodiment of the present invention, a piston ring 1 is provided that has a stainless steel base material 2 having an upper surface, a lower surface, an inner circumferential surface and an outer circumferential surface, the surfaces each having a nitride layer 3 formed thereon, where the nitride layer 3 each is first formed to have a compound layer 4 and a diffusion layer 5, where the diffusion layer 5 of the outer circumferential surface is then exposed by removing the compound layer 4 of the outer circumferential surface, where the exposed diffusion layer 5 has thereafter an ion-plating deposition layer 8 of hard ceramic formed thereon. The piston ring 1 is characterized in that the exposed diffusion layer 5 is removed on the upper and lower corners 7 of the upper and lower surfaces and the outer circumferential surface by chamfering corner regions 6 located around the upper and lower corners 7 before the ion-plating deposition layer 8 is formed.

Abstract: A piston ring has a diamond-like carbon film formed in a thickness of 0.5 to 30 micrometers over an under film on the upper and lower surfaces. The under film is directly formed on the surfaces, or formed on a hard surface treatment layer consisting of a gas nitrided layer or a chromium plating film. The diamond-like carbon is configured with any one of an amorphous carbon structure, an amorphous carbon structure having partly a diamond structure, or an amorphous carbon structure having partly a graphite structure. The under film is comprised of one or more elements selected from the group consisting of silicon, titanium, tungsten, chromium, molybdenum, niobium and vanadium in an atomic content of 70 percent or more and below 100 percent, and the remaining content consisting of carbon, or one or more of said elements in an atomic content of 100 percent. The films may also be formed in the same way on the outer circumferential surface of the piston ring.

Abstract: A piston ring combination including at least one compression ring and at least one oil ring. If a plurality of compression rings are provided, an outer peripheral surface of at least a top ring is formed with a first ion plating layer. The oil ring has a pair of side rails whose outer peripheral surfaces are formed with second ion plating layers. These layers are formed of Cr—N mixture. The first ion plating layer has a porous structure with a porosity ranging from 3 to 10% and a hardness ranging from 1000 to 1500 Hv. The second ion plating layer has a dense structure with a porosity ranging from 0 to 3% and a hardness ranging from 1800 to 2200 Hv.

Abstract: The invention provides a piston ring and piston ring material with excellent properties since not only it has excellent properties as a piston ring, but also excellent in drawability and rolling workability in the manufacturing process of stock, very excellent bending workability can be attained even when relatively high hardness after heat treatment is established, and excellent in properties as a piston ring. The piston ring material essentially consists, by weight of 0.2 to 1.2% C, 5.0 to 25.0% Cr and the balance Fe and incidental impurities, M7C3 type carbide content existing in the structure being 4.0% or less in terms of area percent to attain excellent scuffing resistance and workability. Preferably, C is 0.2 to 0.7%, and Cr is not less than 5.0% but less than 12.0%. Cr (wt. %)/C (wt. %) is 12 to 45, preferably 15 to 45, more preferably 18 to 30. In addition, the piston ring material of the present invention may contain not more than 0.25% Si, not more than 0.30% Mn, at least one not more than 2.

Abstract: According to an aspect of the present invention, a piston ring for use in internal combustion engines is provided that is made of matensite-based stainless steel material containing C of not less than 0.4 and not more than 0.8 weight percent, Si of not less than 0.16 and not more than 0.4 weight percent, Mn of not less than 0.1 and not more than 0.4 weight percent, and Cr of not less than 2.0 and not more than 11.0 weight percent, where the steel material of the piston ring has mainly chromium carbide precipitated in the base texture thereof. The steel material of the first compression ring then has a nitriding layer formed thereon. According to another aspect of the present invention, a combination of compression rings, including a first compression ring 1 and a second compression ring 2, for use in internal combustion engines, is provided. The first compression ring 1 is made of martensite-based stainless steel material containing C of not less than 0.16 and not more than 1.

Abstract: A cast-iron piston ring for a piston of an internal combustion engine includes a ring composed of cast-iron and having a circumferential surface; a nitrided layer covering the entire circumferential surface of the ring, the nitrided layer including a diffusion layer and a connection layer disposed above the diffusion layer in which the diffusion layer and the connection layer both cover the entire circumferential surface of the ring; and a metal layer which is electrodeposited onto the connection layer, which is composed of a metal having a hardness which is less than that of the connection layer, and which has a thickness of less than 5 &mgr;m.

Abstract: A nitrated piston ring for the piston of an internal combustion engine. The piston ring has a circumferential indentation in its flank surface facing away from the combustion pressure. This indentation has a depth of a few Am and receives lubrication to prevent plating of aluminum from the aluminum piston on the flank surface of the piston ring.

Abstract: An improved piston ring is disclosed, together with a process form making the ring. An annular steel base body has a lower layer formed by electro-plating a peripheral surface of the body with either a chromium or titanium nitrided gas. The ring is normally lapped until dull, smooth and free of residual metallic plating nodules, yielding random micro-abrasions in the lower layer. An upper layer of metallic nitride or chromium ceramic is formed onto the lapped lower layer, using physical vapor deposition means.

Abstract: A gas nitrided layer is formed over the entire surface of a piston ring. A physical vapor deposition film of CrN is formed over the gas nitrided layer at the outer circumferential surface. The physical vapor deposition film has oxygen contained in a solid solution state in a crystal structure of CrN in a content of 0.5 to 20 percent by weight, pores dispersed at a rate of 1 to 15 percent within the film and a crystal structure of CrN with a preferred orientation (200) parallel to the surface being covered. The Vicker's hardness of the film is within a range of 1000 to 1800. The physical vapor deposition film of CrN can be formed beneath a wear resistant film covering the outer circumferential surface of the piston ring. The wear resistant film is for instance, a physical vapor deposition film of chromium nitride such as CrN or Cr.sub.2 N.

Abstract: A piston ring is formed over the entire surface with a gas nitrided layer and a hard film with a thickness of 0.5 to 30 micrometers on the gas nitrided layer at the upper and lower surfaces. The hard film comprises diamond-like carbon in which are dispersed one or more elements selected from the group consisting of silicon, titanium, tungsten, chromium, molybdenum, niobium, and vanadium. The diamond-like carbon is configured with any one of an amorphous carbon structure, an amorphous carbon structure having partly a diamond structure, or an amorphous carbon structure having partly a graphite structure. The content of the above elements is 5 to 40 atomic percent, and the hard film has a Vicker's hardness in a range from 700 to 2,000. The hard film may be formed directly on the upper and lower surfaces of the piston ring in a thickness from 0.

Abstract: An object of the present invention is to provide a sliding member which is coated a film having superior wear resistance, superior scuffing resistance and a superior property not to increase an amount of wear on an opponent material (an opponent attacking property). This object can be achieved by providing a sliding member coated by a Cr--V--B--N alloy film 4 on an outer surface 3 thereof. In this case, it is preferable that the Cr--V--B--N alloy film is formed through a physical vapor deposition, particularly ion plating, vacuum deposition, or sputtering. Further, it is preferable that V (Vanadium) content is within the range of 0.1-30 wt. % and the boron (B) content is within the range of 0.05-20 wt. %.

Abstract: A piston ring is formed over the entire surface with a gas nitrided layer and a hard film with a thickness of 0.5 to 10 micrometers on the gas nitrided layer at the outer circumferential surface. The hard film comprises diamond-like carbon in which are dispersed carbides of one or more elements selected from the group consisting of silicon, titanium, tungsten, chromium, molybdenum, niobium, and vanadium. The diamond-like carbon is configured with any one of an amorphous carbon structure, an amorphous carbon structure having partly a diamond structure, or an amorphous carbon structure having partly a graphite structure. The content of the above elements is 5 to 40 atomic percent, and the hard film has a Vicker's hardness in a range from 700 to 2,000. A chromium plating film or ion plating film may be used instead of the gas nitrided layer.

Abstract: A mechanism for forming a liquid-tight seal around the rotary shaft of a liquid pump having a stationary ring attached to the casing of the pump and a rotating ring attached to the rotary shaft and contacting the stationary ring. The stationary ring is formed from baked carbon, while the rotating ring is a sintered product of silicon nitride. The stationary ring has an effective seal width ratio, rp/Di, of 0.07/1 to 0.22/1, where rp is the width of the effective seal surface of the stationary ring and Di is its inside diameter.

Abstract: A hard film is covered on the outer circumferential surface of a piston ring by means of an arc ion plating. The hard film has a mixture of crystal structure of CrN and crystal structure of Mo.sub.2 N containing oxygen in a solid solution state, and comprises chromium at 40 to 78 percent by weight, molybdenum at 3 to 35 percent by weight, oxygen at 3 to 20 percent by weight and the remainder of nitrogen. The crystal particle size is less than 1 .mu.m. The Vickers hardness is within a range from 1600 to 2500. The film thickness is preferably 1 to 60 .mu.m. Carbon in a solid solution state at 0.5 to 8 percent by weight may be substituted for the oxygen. Alternatively, both oxygen and carbon may be contained in a solid solution state with oxygen at 3 to 20 percent by weight, carbon at 0.5 to 8 percent by weight with the total content of carbon and oxygen within 25 percent by weight.

Abstract: A piston ring is formed with a nitrided layer over all surfaces and formed with a composite chromium plating film over the nitrided layer in the outer circumferential surface. The composite chromium plating film has a network of cracks formed on the outer surface and interior. Spherical alumina particles are fixed in these cracks. The average size of the spherical alumina particles is 0.7 to 10 .mu.m and the dispersion ratio of the spherical alumina particles is 3 to 15 percent by volume.

Abstract: A piston ring formed with a nitrided layer over all surfaces and formed with a composite chromium plating film over the nitrided layer in the outer circumferential surface. The composite chromium plating film has a network of cracks formed on the outer surface and interior. Si.sub.3 N.sub.4 particles are fixed in these cracks. The average size of the Si.sub.3 N.sub.4 particles is 0.8 to 3 .mu.m and the dispersion ratio of the Si.sub.3 N.sub.4 particles is 3 to 15 percent by volume.

Abstract: A piston ring having a keystone shape and an orientation feature on one of its surfaces for ensuring proper orientation of the ring during installation. The piston ring preferably has an outer peripheral surface that includes a sealing land with a nitride hardened surface to resist wear during the service life of the piston ring. A tapered surface is also provided on the outer peripheral surface adjacent to the sealing land.

Abstract: A Cr.sub.2 N film or a mixed Cr.sub.2 N and Cr film formed by physical vapor deposition on the outer circumferential surface of a piston ring which is in contact with the inner circumferential surface of a cylinder. The axial width of the outer circumferential surface of the piston ring is 0.6 mm or less. The nitrogen content of the film is 11 to 17 percent by weight. The Vicker's hardness of the film is in the range of HV1300 to HV2000. The thickness of the film is 3 .mu.m to 30 .mu.m.