Abstract: A steel material composition in particular for manufacturing piston rings and cylinder liners, which has a good nitriding capability, contains the following elements in the given proportion related to 100% by weight of the steel material composition: 0.5-1.2% by weight C, 4.0-20.0% by weight Cr, 45.30-91.25% by weight Fe, 0.1-3.0% by weight Mn, 0.1-3.0% by weight Mo, 2.0-12.0% by weight Ni, 2.0-10.0% by weight Si and 0.05-2.0% by weight V. It can be manufactured by manufacturing a melt of the starting materials and casting the melt into a prefabricated mold. Nitridation of the steel material composition which is obtained leads to a nitridized steel material composition which, by virtue of the manufacture with gravity casting, exceeds the properties of tempered cast iron with nodular graphite.

Abstract: An oil scraper piston ring and a method for producing it in which a base body is provided with a running surface profile by machining the radially outer circumferential surface thereof, the running surface profile including two running surface lands and an interposed groove, wherein the running surface profile corresponds to that of the finished oil scraper piston ring, and on the groove side, seen in the circumferential direction, drainage holes are introduced into the groove base, at least the running surface lands are provided with a wear-resistant PVD, DLC or TaC layer and, if needed, the wear-resistant layer is subjected to a polishing, honing or lapping operation.

Abstract: The invention relates to a sliding element, such as a piston ring, having a coating on at least one running surface, which comprises, from the inside out, an adhesive layer (10), a metal-containing, preferably tungsten-containing, DLC layer (12), and a metal-free DLC layer (14), and is characterized in that the ratio of the thickness of the metal-free DLC layer to the thickness of the metal-containing DLC layer ranges from 0.7 to 1.5 and/or to the overall thickness of the coating ranges from 0.4 to 0.6.

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: The invention relates to a slide ring seal, and in particular a running gear seal, at least comprising an angled slide ring and/or counter ring, the radial leg of which forms a sliding region, and the axial leg of which forms a seating for a sealing element, which radially outside of the sliding region, is provided with a projection that at least partially overlaps the radial leg, forming a secondary seal, wherein at least in the region of the radial leg, the projection is provided with a profile, which is supported on the outer circumferential surface of the radial leg, forming anti-contamination lips in the installed state of the slide ring seal, and in particular running gear seal, that profile being supported on the outer circumferential surface of the radial leg when viewed in the axial direction.

Abstract: A method and an apparatus for measuring the light gap tightness of a piston ring, that is provided with a joint and produced so as to be non-round by clamping the open piston ring, while substantially closing the joint, by way of an accessory device in the circumferential direction, and by exerting a defined force in the region of at least one of the joint ends of the piston ring in the direction of a wall of the accessory device, wherein optical means are used to establish whether the joint region of the piston ring which is subjected to the action of the force is seated against the wall of the accessory device in a light-tight manner.

Abstract: The present application relates to a sliding element, in particular a piston ring, having at least one sliding surface which has a coating which has, from the inside outwards, a metal-containing bonding layer and a DLC layer, where the DLC layer is an amorphous hydrogen-free diamond-like carbon layer which has a DLC main layer which extends from the bonding layer to an adjoining DLC covering layer and has a carbon content of more than about 98.5 at %, oxygen and/or hydrogen and/or nitrogen in a proportion of in each case less than about 0.5 at % and an sp2/sp3 ratio of the carbon in the range from about 1 to about 3, and a DLC covering layer which extends from the DLC main layer to the surface of the sliding element and has a lower carbon content and/or higher oxygen content and/or higher hydrogen content compared to the main layer and also metals and/or metal oxides and an sp2/sp3 ratio of the carbon in the range from about 1 to about 3.

Abstract: The invention relates to a sliding element, in particular a piston ring, having at least one running surface. The running surface comprises a coating, which from the inside to the outside has at least one first adhesive layer, a hard hydrogen-free DLC layer, a second adhesive layer, a soft hydrogen-containing, metal and/or metal carbide-containing DLC layer, which is softer than the hard hydrogen-free DLC layer, and a hard hydrogen-containing DLC layer, which is harder than the soft hydrogen-containing, metal and/or metal carbide containing DLC layer.

Abstract: The present application relates to a sliding element, in particular a piston ring, having a coating (10) on a substrate (12), which forms at least one sliding surface of the sliding element. The coating (10) has, from the inside outwards, a carbide or nitride layer (16), then a carbide-containing (preferably PVD-) TLC layer (17), then a metal-free PVD-TLC layer (22) and then a metal-free PACVD-TLC layer (18).

Abstract: A compression piston ring for an internal combustion engine, comprising a sliding surface formed by two ridges, upper and lower flank surfaces, and an inner circumferential surface, wherein the lower ridge runs at least in some regions parallel to the counter sliding surface and the upper ridge is designed as a taper faced Napier element.

Abstract: In order to avoid burn traces on piston rings, it is proposed to provide the piston ring with a wear-protection coating which consists of a material with a thermal conductivity of at least 180 W/(m·K). At least 5% vol. of the wear-protection coating consists of aluminum nitride.

Abstract: A device for measuring edge and rounding features on a piston ring includes a planar support element for the piston ring, a stop operatively connected thereto for bearing defined piston ring sections thereon, and a measuring unit, which is disposed at a predefinable angle with respect to the support element or the stop.

Abstract: A coated piston ring having a base body of chromium steel with more than 10 wt.-% chromium and having an inner circumferential surface, a first flank surface, a second flank surface and an outer circumferential surface. The first flank surface comprises a nitride diffusion layer with a layer thickness of from 5-300 ?m, a nitride connecting layer with a layer thickness of from 0.5-15 ?m on the nitride diffusion layer, and an oxide layer with a layer thickness of from 0.05-3 ?m on the nitride connecting layer. The second flank surface comprises the nitride diffusion layer, and the outer circumferential surface comprises the nitride diffusion layer and a chromium solid particle layer with 0.1-30 vol.-% solid particles, relative to the total volume of the chromium solid particle layer on the nitride diffusion layer.

Abstract: A slide ring seal, and in particular a running gear seal, including an angled slide and/or counter ring, the radial leg of which is provided with a sliding surface and the axial leg of which forms a seating for a trapezoidal sealing element, wherein the outer ends of the axial leg have recesses, into which engage projections on the sealing element to form anti-rotation locks, wherein the transition area from the axial leg to the radial leg of the slide and/or counter ring provided beyond the sliding surface has a profiling, into which a section of the sealing element having an approximately corresponding construction engages.

Abstract: A sliding element, in particular a piston ring or a cylinder liner, comprising at least one a-C:H:Me layer, where Me is germanium and silicon, having a layer thickness of 10-40 ?m, is provided.

Abstract: A method for producing a recessed steel piston ring provided with a wear-resistant layer includes generating a main body that has a recess on the running surface side and that, in the region where a lower flank of the main body transitions into the running surface is worked so that a chamfer is created, providing the running surface and at least portions of the chamfer with at least one wear-resistant layer, nitriding the circumferential surface and the lower and upper flanks of the main body that are not provided with the wear-resistant layer so that a section having a defined width and having no nitride layer remains on the flank adjacent the chamfer, and removing the at least one wear-resistant layer to such an extent that a substantially sharp, but unnitrided functional edge is created in the region where the lower flank transitions into the running surface.

Abstract: An assembly tool for inserting a slide ring or counter ring of a slide ring seal, in particular a running gear seal, cooperating with an elastic sealing body into an associated housing part, the assembly tool including a number of clamping elements formed as arcuate segments and an assembly O-ring, wherein the clamping elements engage around the slide ring or counter ring, and around the sealing body and the assembly O-ring in a manner that corresponds to the circumferential length thereof, and the clamping elements are advanceable in the direction of the housing part in order to mount the sealing body within this housing part.

Abstract: A piston ring system, having an internal diameter >400 mm, for a piston of a two-stroke internal combustion engine, includes at least a first and a second piston ring each having a convex running surface with a crest of the convexity in contact with a cylinder wall and each being inserted into a respective first and second piston ring groove in the piston, wherein the first piston ring faces a combustion chamber and the second piston ring is disposed axially beneath the first piston ring, and wherein the crest of the convexity of the first piston ring is disposed beneath a radial plane passing through a midpoint of axial height of the first piston ring, and the crest of the second piston ring is disposed above a radial plane passing through a midpoint of axial height of the second piston ring.

Abstract: A multi-part piston ring, containing an at least single-part spring support which is provided with a piston ring joint region and an at least single-part spring element, which is positioned in a groove provided in the region of the inner circumferential face of the spring support, wherein the wall thickness of the spring support is essentially equal in the region of the ends of the spring support facing the piston ring joint and in the rear region of the spring support, and a pocket which extends over a circumferential range of at least 60° and is created by local reduction of the wall thickness of the spring support is provided in each case between the rear region and the piston ring joint ends.

Abstract: A method for producing a piston ring for an internal combustion engine includes providing, a substrate and applying a coating by means of thermal spraying of a powder including solid lubricants on the substrate, having the elemental proportions of 15-30% by weight of iron, Fe; 15-30% by weight tungsten, W; 25-35% by weight of chromium, Cr; 10-35% by weight of nickel, Ni; 1-5% by weight of molybdenum, Mo; 0.2-3% by weight of aluminum, Al; 3-20% by weight of copper, Cu; 1-10% by weight of carbon, C; 0.1-2% by weight of sulfur, S; and 0.1-2% by weight of silicon, Si. The resultant piston ring and coating are also provided.