Abstract: A wear-resistant and low-friction coated piston ring and a preparation method therefor are provided. The OD surface diamond-like carbon coating consists sequentially of a first metal interlayer, a second metal interlayer, a gradient DLC layer, alternating high/low hardness DLC layers, and an outer running-in DLC layer. The side surface diamond-like carbon coating consists sequentially of a metal interlayer, a gradient DLC layer, and alternating high/low hardness DLC layers. The preparation method employs physical vapor deposition to sequentially deposit composite DLC coatings on the OD surface and side surface of the piston ring. The coating is a tetrahedral amorphous carbon structure, exhibiting good thickness uniformity and fine grain structure. This improves the wear resistance of the piston ring's OD surface and side surface, reduces the aggressiveness of the piston ring side surface against the piston ring groove, and meanwhile avoids adhesion.

Abstract: Provided is a combined oil ring that can provide reduction in oil consumption of the engine oil without degrading the oil sealing performance between the lower surface of the side rail and the lower surface of the oil ring groove even when the tension of the combined oil ring is reduced.

Abstract: The method for forming cutters includes applying a protective layer on an O-ring so as to form a protected O-ring. The protected O-ring is placed around a cutter body having a substrate section and diamond section with a metallic binder. The method includes inserting the cutter body into the pod cavity and leaching the metallic binder through an end portion of the diamond section for at least one day at 60 degrees Celsius or higher so as to form a polycrystalline diamond compact cutter from the cutter body. The protected O-ring seals the substrate section during the step of leaching. The step of leaching forms an exposed O-ring from the protected O-ring with a hardness reduction and a modulus reduction that identifies a time window for maintaining a sealing force to protect the substrate, while achieving the target profile of the diamond table for a high quality and reliable cutter.

Abstract: In this piston ring combination, a second outer peripheral surface, which is the outer peripheral surface of a second ring, has a second protruding surface curved into a convex shape, and a pair of third outer peripheral surfaces, which are the outer peripheral surfaces of a pair of segments, each have a third outer peripheral area in which a third protruding surface is formed, the third protruding surfaces being curved into convex shapes. In at least one of the pair of third outer peripheral surfaces, the peripheral edge on a crank-chamber side is positioned farther outward in the diametrical direction than the peripheral edge on a combustion-chamber side, and a peak of the third protruding surface is positioned nearer to the crank chamber than the center of the third outer peripheral surface.

Abstract: A wear resistant coated piston ring for an engine is provided. The piston ring includes a coating disposed on a ring body. The coating includes initially includes alternating first and second layers, wherein the first layers include trivalent chromium, and the second layers include nickel and phosphorous. The first layers are applied by depositing a trivalent chromium electrolyte, specifically Cr3+ electrolyte. The second layers are applied by electroless deposition. The coating is left in the as-is condition and is not heat treated before being disposed on a piston and then in an engine. The coating is naturally exposed to heat while the engine is running, and this heat causes the chromium, nickel, and phosphorous of the layers to diffuse and form a surface layer on a compound layer. The surface layer includes trivalent chromium, and the compound layer includes a ternary compound of chromium, nickel, and phosphorous.

Abstract: A piston ring for internal combustion engines provided with a ferrous alloy base includes an annular outer surface on which a coating including at least one outer layer is applied deposited on an adhesive layer, the outer layer being provided with a variable thickness, in such a way that the thickness of the outer layer gradually increases from 90° and 270° towards 0° and 360° respectively, with the thickness attaining its maximum value in the region of 10° and 350° and slightly decreasing towards 0° and 360° so as to ensure an optimal working condition, minimizing the contact pressure and consequently the accelerated wear in the vicinities of the ends of the ring, in addition to preventing and/or impeding the detachment of the outer layer of the coating.

Abstract: A sliding component includes a plurality of dimples 10 disposed on at least one of sliding surfaces of a pair of sliding parts relatively sliding on each other, the plurality of dimples 10 is provided mutually independently of the other dimples, and the plurality of dimples 10 has an area ratio set lower on the low-pressure fluid side of the sliding surface than on the high-pressure fluid side. On the sliding surface, a liquid film on the high-pressure fluid side is thickened by dynamic pressure effect to improve fluid lubricity, and a liquid film on the low-pressure fluid side is thinned to prevent leakage.

Abstract: Provided is a piston ring such that it is possible to sufficiently inhibit adhesive wear when the piston ring is mounted to a piston for a diesel engine in which at least the piston ring groove in the piston is formed from steel or cast iron. Disclosed is a piston ring mounted to a piston for a diesel engine, wherein the load length ratio (Rmr2) (in accordance with JIS B0601:2001) of the top surface and bottom surface of the piston ring satisfies each of the following conditions: Rmr2 (0.5%, 0.3[mu]m)=20% and Rmr2 (0.5%, 0.4[mu]m)=40%.

Abstract: A piston ring, in particular a compression piston ring, includes a main body, which has a radially outer running surface, a radially inner circumferential surface, an upper and a lower flank surface, and a joint, wherein the running surface is provided with at least one circumferential recess which receives a wear-resistant coating, in particular a PVD coating, and wherein, starting from respective end faces of the joint, as seen in the circumferential direction of the main body, a land shoulder is integrally formed on the main body outside the coating and extends at a predetermined radial height over a predetermined circumferential length on both sides of the joint.

Abstract: Disclosed is a piston ring (1) having a substrate (10) to which a wear resistant coating (20) is applied that includes at least one first element with a melting point Tm?700° C. The wear resistant coating (20) contains at least one second element with a melting point Tm>760° C. The wear resistant coating also includes droplets (30) which have a diameter (D) and which contain at least the first element, wherein at least 90% of the droplets (30) have a value 1 ?m?D?10 ?m. In the method for producing a wear resistant coating (20) using an arc evaporation technique, the target material includes at least one first element with a melting point Tm?700° C. and at least one second element with a melting point Tm>760° C., wherein the quantity of the second material contained in the target material is such that the melting point (Tm) of the target material ?1000° C.

Abstract: A gasket device is for use in a pre-filled syringe having a cylinder for containing liquid drug in sealing tightness. The liquid drug is pressurized by moving a plunger in the cylinder. The gasket device includes a gasket body, having resiliency, and movable toward the liquid drug with a front end of the plunger. A laminate layer is formed from PTFE (polytetrafluoroethylene), and disposed to cover a surface of the gasket body. The laminate layer includes a sealing portion, having a thickness Da, for sliding on an inner surface of the cylinder in sealing tightness. A liquid receiving portion has a thickness Db, for contacting the liquid drug in the cylinder. The thickness Da is from 10 microns to 40 microns. The thickness Db is from 20 microns to 50 microns. A ratio R1 of the thickness Db to the thickness Da is from 1.25 to 2.00.

Abstract: A sliding member for an internal combustion engine includes: a substrate and a coating obtainable by thermally spraying a powder, having the element proportions of 55 to 75 wt % of chromium, Cr; 3 to 10 wt % of silicon, Si; 18 to 35 wt % of nickel, Ni; 0.1 to 2 wt % of molybdenum, Mo; 0.1 to 3 wt % of carbon, C; 0.5 to 2 wt % of boron, B; and 0 to 3 wt % of iron, Fe.

Abstract: A structure of a titanium-alloy piston ring is configured to be installed in an engine and includes a titanium-alloy matrix. The titanium-alloy matrix has an outer periphery receiving a hardening treatment (such as receiving a nitrogen treatment, or being coated with a diamond-like carbon film, or receiving a nitrogen treatment and then being coated with a diamond-like carbon film), so as to make the piston ring have improved abrasion-resistant strength, hardness, and wear resistance, thereby extending the normal service life of the piston ring.

Abstract: A structure of a piston ring to be installed in an engine includes a matrix wherein a laminated intermediate layer is formed on a surface of the matrix from hard chromium (Cr), chromium nitride (CrN) and titanium carbide (TiC) in order, and a diamond-like carbon film (DLC) is coated on an outer periphery of the intermediate layer, so that the piston ring is wrapped by a skin with a progressive structure having gradient distribution of hardness. The structure formed from the diamond-like carbon film provides low wear rate and low friction coefficient, while applying a high bonding force to the matrix and making the piston ring have an improved normal service life that meets the related environmental regulations.

Abstract: [Task] The chromium nitride ion-plating coating has a property that it is hard but is liable to peel off. Year by year, the required level of wear resistance and scuffing resistance becomes higher in a diesel engine. The property of a coating is improved to enhance the wear resistance and scuffing resistance and also to improve resistance against peeling off. [Means for Solution] (1) Composition is mainly composed of chromium, nitrogen, and carbon, and the concentration of carbon relative to the total concentration of the main components is from 4 to 8% by weight. (2) The crystal structure is that texture of the CrN (111) plane orientation is from 0.4 to 2.0 in terms of a CrN (111) structural coefficient. (3) Vickers hardness is from Hv 1600 to Hv 2000.

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, 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: A sliding element, in particular a piston ring, preferably made of cast iron or steel, has a coating which has a plurality of layers of CrN (14) and a-C:H:Me coatings (16) alternately. In a method for coating the sliding element, in particular a piston ring, preferably made of cast iron or steel, a plurality of layers of CrN and a-C:H:Me coatings are applied alternately.

Abstract: A piston ring which is provided with a carbon-based coating which has a low friction property and wear resistance, that is, a piston ring which has a carbon-based coating formed over its sliding surface, in which piston ring, the coating is a multilayer coating comprised of two types of layers having different hardnesses laminated in at least two layers, a hardness difference between the two types of layers is 500 to 1700 HV, a high hardness layer has the same or greater thickness than a low hardness layer, and the coating as a whole has a thickness of 5.0 ?m or more. The high hardness layer has a thickness of 5 to 90 nm. The surface on which the coating is formed has a base material roughness of 1.0 ?mRz or less.

Abstract: A piston ring is provided at its outer periphery with a sliding surface, wherein in a cross section thereof which is perpendicular to a radial direction of the piston ring, the sliding surface includes a first sliding surface which occupies a predetermined region from one end thereof, and a second sliding surface which occupies a region extending from one end to the other end of the first sliding surface, the first sliding surface is formed of hard film, the second sliding surface is not formed of hard film, and the second sliding surface exists at a position deviated inward from a phantom line extending from the first sliding surface toward the other end.

Abstract: A piston ring having a base body, which comprises a running surface provided with at least one chamber, an upper and a lower flank surface, and an inner circumferential surface, wherein the running surface is provided with at least one PVD layer such that the same is adjusted to the contour of the running surface without completely filling the chamber, wherein the respective edge region is provided with a layer thickness, b that is reduced compared to the layer thickness, a of the chamber as a function of the configuration of the chamber.

Abstract: A sliding element comprises at least one surface for sliding contact with a running face, wherein a wear layer and a run-in layer made from carbon are applied to the surface, and is characterized in that the run-in layer comprises hydrogen and nanocrystalline carbide phases. In a method for manufacturing a sliding element, the run-in layer is applied by means of a PVD process. A sliding system has an above-described sliding element and a body having a running face. A coating for a sliding element comprises a wear layer which can be applied to the upper side of the sliding element, and a run-in layer which is configured as a carbon layer, and is characterized in that the run-in layer comprises hydrogen and nanocrystalline carbide phases.

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 dispenser for dispensing a liquid onto a substrate includes a dispenser body having an output and a reservoir in fluid communication with the output, the reservoir being defined by a wall and adapted to hold a supply of liquid to be dispensed. A piston is disposed in the reservoir and adapted to pressurize the liquid so that an amount of liquid is dispensed from the output of the dispenser. The piston includes a base portion having an outer periphery and having a first hardness, and a skirt portion integrally molded to the outer periphery of the base portion and having a second hardness lower than the first hardness. A two-shot molding operation may be used to form the piston with the base portion being, for example, formed in the first shot of the molding operation and the skirt portion being formed in the second shot of the molding operation.

Abstract: A downhole pump for a well has a barrel and a plunger. The barrel has a passage extending along the length of the barrel, with the passage having an inside diameter. The plunger has an outside diameter and is received by the barrel passage for relative reciprocal movement. One of the barrel or the plunger is equipped with wear rings, with a wear ring at one or at each end. The wear rings are made of a material that is harder than the material of the respective plunger or barrel. The wear rings provide protection from abrasion, particularly in a sandy well.

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: 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: The invention relates to a combustion gas seal for injectors and to a seal structure disposed therewith, for preventing leakage of combustion gas in a state in which an injector is mounted to an engine head. And, the number of parts is reduced, vibration and noise are reduced, and sealing performance is improved. A tapered surface, in which an clearance between the tapered surface and an inner peripheral surface of a mounting hole of the engine head narrows from an engine bore side towards an atmospheric side, is disposed at a groove bottom of an attachment groove of the injector, and an abutment portion that abuts against the tapered surface is disposed at the combustion gas seal for injectors.

Abstract: A piston ring comprises a coating of a wear-resistant composite composition, particularly intended for high temperature applications. The wear-resistant composite composition comprises a ceramic compound and at least 50 volume %, based on the total volume of the wear-resistant composition, of an intermetallic nickel-aluminide chosen from the group consisting of NiAl and Ni3Al. A piston ring comprises a wear-resistant composite composition, particularly intended for high temperature applications. The wear-resistant composite composition comprises a ceramic compound and at least an intermetallic nickel-aluminide chosen from the group consisting of NiAl and Ni3Al.

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: A dual seal assembly for providing a seal between a reciprocating rod and the gland is described. The dual seal includes first and second axially adjacent annular seal elements. The first seal element is constructed of a material having a different hardness than the material forming the second seal element. The first and second seal elements each include a seal edge contacting the rod to provide a respective seal between the first and second seal element and the rod. At least a portion of one of the first seal element and the second seal element engages the gland to form the seal between the rod and the gland. By varying the hardness of the materials forming the seal elements, the first seal element and the second seal element can be configured to provide different functions within the dual seal assembly and can cooperatively provide an effective fluid seal under a wide range of operating conditions.

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: Elastic sealing ring for sealing between a displaceable and/or rotatable component, such as a piston (2), piston rod (3), shaft etc., and a surrounding component, such as a cylinder block (1), a cylinder end wall etc. The sealing ring is adapted so as to be mounted in a groove in one component and has at least one sealing surface (28; 31, 32) intended for bearing against the other component, and comprises two materials with different properties. The sealing ring is made with an inner injection-molded core (17) made of a first material with first properties and an outer layer (18) made of a second material with in part second properties and injection-molded together with the core. This material is fused together with the material in the core in the boundary zone. The sealing surface is at least partly formed by a part of the outer layer (18), which has lower friction on contact with a component part bearing against it than the material in the core (17).

Abstract: A material comprised of two different polymers so that the material exhibits anisotropic properties. The anisotropic properties exhibit hardness and wear resistance along with flexibility. The anisotropic material is made up of a hard segment polymer and a soft segment polymer having contact with each other. This anisotropic material can be used to make seals, which exhibit these same properties and are therefore appropriate for use in high-pressure situations, where they will have a longer life than seals currently on the market.

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: The present invention provides a piston ring and a combined structure of a piston ring and a ring groove of piston having a hard carbon film which is excellent in wear resistance, scuffing resistance, cohesion resistance relative to the piston material and in peeling resistance. The above-mentioned object of the invention is achieved by continuously forming a hard carbon film 2 containing one or more elements selected from Si, W and Ni, or all of the outer peripheral surface 4, the inner peripheral surface 5, the top surface 6 and the bottom surface 7 of the piston ring 1. The hard carbon film contains Si and has an Si-containing film serving as a primer film for the hard carbon film. A Cr film should preferably be formed as primer film for the hard carbon film. It is desirable to have an ion-plating film as a primer film formed on the outer peripheral surface of the piston ring.

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: A dual seal assembly for providing a seal between a reciprocating rod and the gland is described. The dual seal includes first and second axially adjacent annular seal elements. The first seal element is constructed of a material having a different hardness than the material forming the second seal element. The first and second seal elements each include a seal edge contacting the rod to provide a respective seal between the first and second seal element and the rod. At least a portion of one of the first seal element and the second seal element engages the gland to form the seal between the rod and the gland. By varying the hardness of the materials forming the seal elements, the first seal element and the second seal element can be configured to provide different functions within the dual seal assembly and can cooperatively provide an effective fluid seal under a wide range of operating conditions.

Abstract: There are disclosed a piston ring material and a piston ring both having such superior properties contradictory each other as the sliding property required in a piston ring and the mechanical properties of a steel wire material subjected to a manufacture process. The piston ring material or the piston ring consists essentially, by mass, of not less than 0.3% but less than 0.8% C, 0.1 to 3.0% Si, 0.1 to 3.0% Mn, 0.03 to 0.3% S, 0.3 to 6.0% Cr, preferably 3.0 to 6.0% or 0.3 to 1.0% Cr, 0 to 3.0% Cu, and the balance Fe, and the distribution state of sulfide inclusions with a maximum diameter/minimum size≧3 observed on structure parallel to the outer peripheral surface of the formed piston ring is such that an intersecting angle made between straight lines passing the maximum size of two of the sulfide inclusions is not more than 30 degrees. Further, the area ratio of nonmetallic inclusions occupying the structure is 2.

Abstract: A piston ring is formed over the entire surface with a gas nitrided layer. A diamond-like carbon film is formed in a thickness of 0.5 to 30 micrometers over the gas nitrided layer at the upper and lower surfaces. The diamond-like carbon film has a surface structure in which diamond-like carbon has been deposited in nodular shapes in sizes of 0.5 to 5 micrometers. 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.

Abstract: Disclosed is a gas cylinder type height-adjusting apparatus of a swivel chair which has a simple structure and thereby can be manufactured at a low cost. In the apparatus, an actuating pin opens an orifice so that working fluid can flow from the first chamber through the second chamber into the third chamber when the actuating pin is pressed down, while the actuating pin blocks up the orifice when the actuating pin is not pressed down. The orifice is formed in an actuating pin socket manufactured by coating synthetic resin after an integral single forming of a single material. The first chamber is defined by an alternating piston which is manufactured by coating synthetic resin after an integral single forming of a single material. The shaft bearing member has a shape of a single annular ring whose upper and lower surfaces are curved surfaces curved with a predetermined curvature or tapered surfaces tapered at a predetermined angle.

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: The present invention aims at reducing the amount of oil consumption in a piston using a piston ring continuously formed of resin without being provided with an abutment. A stepped portion is formed on a third land, which is located below a second ring having a construction wherein an outer ring continuously formed of polyimide without being provided with an abutment is pressed against a cylinder wall by a coil expander via an inner ring continuously formed of PTFE without being provided with an abutment. Oil spill ports are provided so as to allow communication between the stepped portion and an inner wall of the piston.

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: 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 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: Wear resisting steel, a sliding member for a cylinder in an internal combustion engine, and a ring spring consist of: carbon: equal to or less than 2.2% by weight; silicon: equal to or less than 1.2% by weight; manganese: equal to or more than 0.2 % by weight and less than 1.20% by weight; chromium: equal to or less than 16% by weight; phosphorus: equal to or less than 0.08% by weight; sulfur: equal to or more than 0.15% by weight; other compositions: equal to or less than 2.0 % by weiht; and the balance substantially consisting of iron. The surfaces thereof may be sulphurized. The steel has excellent resistance to wear and scuffing, provides high strength, great elongation, and high toughness, and also provides good machinability.

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: An outer circumferential surface of a piston ring is covered with a physical vapor deposition film, chemical vapor deposition film or composite chromium plating film. The physical vapor deposition film or chemical vapor deposition film consists of chromium or titanium nitrides (for instance CrN, Cr.sub.2 N, a mixture of Cr and Cr.sub.2 N, TiN) or carbides (for instance CrC, TiC). The composite chromium plating film contains carbides (for instance SiC) or nitrides (for instance Si.sub.3 N.sub.4) or oxides (for instance Al.sub.2 O.sub.3) in cracks in the film. A cylinder liner is made of spheroidal graphite cast iron.