Abstract: A wear ring for a piston of a die-casting apparatus comprises an annular body having a gap extending therethrough, the gap being configured to define at least two circumferentially offset pairs of circumferentially spaced apart facing surfaces. The annular body comprises an axial end face having at least one arc-shaped recess formed therein.

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: Method for producing a piston ring having an axial height <2 mm, said piston ring having a radially outer running surface provided with at least one rail, a radially inner circumferential surface, and upper and lower flank surfaces extending therebetween, wherein said rail is provided with a contour that is tapered radially outwardly, thereafter the running surface, together with the flanks of the tapered rail, is provided with at least one wear-resistant layer, and then only the flank of the rail that is to form a scraping edge is subjected to at least partial material removal to form the scraping edge.

Abstract: The invention provides a low tension piston ring having a finished outer diameter and negligible tangential tension. The method includes the steps of machining a stock bar to an initial outer diameter slightly greater than the finished outer diameter of the piston ring, finishing the initial outer diameter of the stock bar to a rounded profile having a nominal diameter equal to the finished outer diameter, and machining the stock bar to the preferred cross-section. Dykes-type piston rings can have keystone or semi-keystone shaped cross-sections. The method continues by detaching the piston ring from the stock bar using a parting tool in response to completing all tension inducing operations including the steps recited above. The method continues with the steps of lapping the piston ring to a final longitudinal thickness and cutting the piston ring longitudinally to form a final gap.

Abstract: A method for manufacturing an annular tribological component in the form of a seal or a sliding bearing of a brittle material. In order to attain the necessary sealing action even with a segmented construction, without expensive reprocessing being necessary in connection with the manufacture of segment surfaces bounding on one another, it is proposed that the annular component be formed of segments made by breaking a ring element and that the segments be assembled such that fractured surfaces fitting one another lie one upon the other.

Abstract: A combined apparatus for making piston rings is disclosed which is provided with an interior-exterior working machine (1) operable under synchronous control by an NC unit (36) for machining both inside and outside of a workpiece (16) composed of a stack of piston ring workpieces brought and held together; a severing machine (41) for severing the workpiece (16) longitudinally thereof; and a common bed (1a), wherein the interior-exterior working machine (1) as a first machine body and said severing machine (41) as a second machine body are mounted adjacent to each other on the common bed (1a).