Abstract: A cylinder for an opposed-piston engine is equipped with a cylinder bore that provides solid lubrication of bore/piston surface interfaces in top ring reversal zones of the cylinder bore.

Abstract: A cylinder for an opposed-piston engine is equipped with a cylinder bore that provides solid lubrication of bore/piston surface interfaces in top ring reversal zones of the cylinder bore.

Abstract: A piston ring is to be mounted in a groove in a piston. The piston ring has sidewalls for engaging sidewalls of the piston ring groove. Each of the sidewalls of the piston ring is hardened in respective localized areas. The localized areas each include a band of hardened material extending around each respective sidewall of the piston ring near the outer periphery of the piston ring. The hardened areas terminate short of the outer periphery of the piston ring. The piston ring due to the termination of the hardened areas short of the outer periphery of the piston ring has unhardened side surface areas immediately adjacent the outer periphery thereof for location adjacent the corners of the piston ring groove at the outer periphery of the piston. The localized areas are hardened by moving a piston ring blank relative to a laser beam, after the piston ring blank is machined.

Abstract: Disclosed is a coating for bearing faces of piston rings and a powder composition for plasma spray application of such coating. The plasma spray powder comprises 94%-98% by weight of aluminum oxide and titanium oxide and 2%-6% by weight of yttrium oxide. The inclusion of yttrium oxide in the aluminum oxide-titanium oxide coating composition reduces the tendency of the coating to blistering and spalling which resulting in coating loss during use of the ring. Intra-coating delamination is substantially reduced or eliminated.

Abstract: A rolled steel oil control piston ring for internal combustion engines is of generally U-shaped cross section with a pair of opposed rigid sidewalls projecting inwardly of the ring from a central peripheral wall thereof. A pair of flat-faced solid scraper rims formed by closed pleats rolled from the peripheral wall extend outwardly of the ring. The ring is made by rolling flat strip steel stock through a series of profiled rollers. Pleats are formed in the central portion by the profiled rollers and the pleats are closed on themselves to provide the solid scraper rims. The finished strip is then punched to provide the vent openings in the peripheral wall, and coiled and cut to form individual piston rings.

Abstract: A retaining ring structure is adapted to be located in a circumferential groove in a first member and to engage a second member to restrain relative axial movement of said members under thrust loading. The retaining ring structure includes a ring portion of L-shaped cross section having a leg portion and a foot portion. The free end of the leg portion fits into the groove and the foot portion engages a surface of the member adjacent the groove. A surface of the leg portion is adapted to contact the sidewall of the groove and is undercut so as to avoid contact with the edge of the groove. One specific retaining ring structure includes a pair of sector ring portions in nested relation with the outer apex of the L-shape of one of the sector ring portions located at the inner apex of the L-shape of the other sector ring portion.

Abstract: The life of silicon carbide grinding wheels is increased when operating against plasma applied coatings of mixed oxides of refractory metals on a cast iron substrate. The invention contemplates the inclusion of certain metal fluorides in the refractory metal oxide powder prior to plasma application, coating by plasma spray, and then grinding with a silicon carbide grinding wheel with reduction in or elimination of in-cycle dressing of the wheel.

Abstract: A rolled steel oil control piston ring for internal combustion engines is of generally U-shaped cross section with a pair of opposed rigid sidewalls projecting inwardly of the ring from a central peripheral wall thereof. A pair of flat-faced solid scraper rims formed by closed pleats rolled from the peripheral wall extend outwardly of the ring. The ring is made by rolling flat strip steel stock through a series of profiled rollers by guiding the edges of the stock without deforming the same, while taking up dimensional variations of the stock by displacement of the central portion of the strip. Pleats are formed in the central portion by the profiled rollers and the pleats are closed on themselves to provide the solid scraper rims. An extrusion-like profile-reducing rolling step provides dimensional accuracy to the finished strip which is then punched to provide the vent openings in the peripheral wall, and coiled and cut to form individual piston rings.

Abstract: A one-piece annular oil control piston ring for internal combustion engines is adapted to be received with a peripheral groove in a piston. The ring is of generally U-shaped cross section defined by a pair of opposed sidewalls which project inwardly of the ring from a central peripheral wall thereof. A pair of scraper rims projects outwardly of the ring from the outer face of the peripheral wall. Spring members are cut from the peripheral wall and project between the sidewalls inwardly of the ring a distance sufficiently inwardly of the sidewall edges to enable the spring members to engage the back wall of the piston groove in which the ring is disposed. The spring action of the spring members biases the piston ring outwardly of the groove so that the scraping rims are maintained in scraping engagement with the cylinder walls.

Abstract: A low friction piston ring of split annular construction has a circumferentially extending recess formed at its upper outer portion to define an outer radial ledge which divides the outer axial surface of the ring into a recessed outer face and a reduced (as compared to the total outer axial surface) bearing surface. The bearing surface preferably has a wear resistant coating thereon. The outside diameter of the recessed outer face is less than the outside diameter of the bearing surface by an amount at least equal to the radial wear depth of the bearing surface. A peripheral recess is also formed at the upper-inner portion of the ring to reduce or eliminate torsional twisting of the ring. The ring provides a reduction in frictional resistance between the ring and the cylinder wall, good sealing against gas blow-by and enhanced engine performance and exhaust emissions control.

Abstract: A method for coating the faces of parts having faces and backs, includes assembling the parts so that the faces and backs thereof define two opposed coating surfaces. The parts may be staggered, and alternate parts have their faces disposed in opposite directions, with faces recessed with respect to the backs of the adjacent parts. Both coating surfaces therefore comprise a plurality of recessed part faces interspersed with part backs.A hardenable coating such as a molten hard facing material is applied to both of the coating surfaces and allowed to harden. After hardening, the surfaces are ground to reduce the thickness of the hardened coating sufficiently to expose the part backs, leaving a desired residual layer of coating adhered to the recessed part faces. The parts are then disassembled to provide a plurality of separate parts, each having a coating on the face thereof.

Abstract: A method of applying a refractory coating or facing to a ferrous metal substrate that is in the form of a finished article, such as that of a piston seal or the like, and that has sections of such small dimensions as to be easily distorted by heat. The method includes an induction heating step carried out under conditions so controlled as to effect a bond of greatly improved strength in shear between the coating and substrate without, however, causing heat distortion of even the small dimensioned sections beyond functionally permissible limits. An agent capable of effecting diffusion bonding, such as free nickel, or an alloy or mixtures containing free nickel or an equivalent bonding element, is made available at the interface in the coating and substrate to facilitate the obtaining of such greatly improved bond as a result of the induction heating step. The bond obtained is in excess of 10,000 psi in shear and generally equal to or in excess of the tensile strength of the refractory coating.

Abstract: This invention relates to an alloy useful as a hard facing material. The alloy comprises a matrix such as a nickel-chromium matrix containing a separate interstitially boron-hardened tungsten phase. The alloy is used as a facing or coating for a number of base materials, and in particular as a piston ring facing. The invention is also concerned with a method of making said alloy by utilizing a plasma jet spray technique.

Abstract: A plastic ring for internal combustion engine pistons. In a preferred embodiment, the ring has a flat outer diameter adapted to engage the inner diameter of a compression piston ring and an inner diameter adapted to engage the backwall of the ring groove. An axial groove slightly spaced from the outer diameter extends into the ring from the top thereof, whereby combustion gases will expand the ring so that it acts as a circumferential expander for the compression ring while preventing blowby of gases through the ring groove. In another modification, the ring is used with its outer diameter acting against the cylinder wall.