Mahle International Gmbh

Fabio Mendes De Araujo

Jose Valentim Lima Sarabanda

Gisela Ablas Marques

Erich John Rabassa

Jason Bieneman

Petru M Berghian

Ashfaque Ahamed

Kaushik Kirana Prasad

A split piston ring unit may include a first ring body, a second ring body, and a spacer insert. The first ring body may define a first circumferential gap. The second ring body may define a second circumferential gap. The spacer insert may be coupled to the first ring body and the second ring body. The first ring body and the second ring body may be arranged coaxially and oriented in an offset orientation where the first circumferential gap and the second circumferential gap are disposed circumferentially offset from one another by an offset distance. The spacer insert may be disposed in the offset distance between the first circumferential gap and the second circumferential gap to maintain the offset orientation.

Split piston ring unit

A piston ring includes a split annular body having an outer circumferential surface, an intermediate coating on the outer circumferential surface, a first layer on the intermediate coating, the first layer having a first hardness and a first porosity, and a second layer on the first layer, the second layer having a second hardness that is less than the first hardness, and having a second porosity that is greater than the first porosity.

Piston ring and method of manufacture

A piston assembly for an internal combustion engine includes a cylinder bore and a piston having exactly two ring grooves, a scraper ring positioned in the upper ring groove, and an oil control ring positioned in the lower ring groove. A constant twist occurs in the scraper ring about a rotational center of the cross-section, the constant twist occurring at each cross-sectional location of the scraper ring about the circumference of the ring and between adjacent free ends of the ring. The oil control ring can be of a multi-segmented U-flex design, with a coil spring mounted in a channel thereof. The combination of the two rings leads to improved sealing and oil control so that the piston can be manufactured with only two rings, thus reducing overall weight and cost.

Piston having two piston rings

A piston ring and a method of manufacturing a piston ring for a piston of a reciprocating internal combustion engine. The piston ring comprises a body having an outer circumferential surface. A tribological coating is formed on the outer circumferential surface of the body. The tribological coating has a dual layer or a triple layer structure and includes a relatively hard base layer and a relatively porous top layer overlying the base layer. The tribological coating may be provided with varying thickness such that its thickness increases gradually from 90&#xb0; towards 0&#xb0; in a first radial direction of the piston ring and from 270&#xb0; towards 360&#xb0; in a second radial direction of the piston ring reaching its maximum value in the region of 0&#xb0; and 360&#xb0;, i.e. the tips of the piston ring.

A piston ring and a method of manufacturing a piston ring for a piston of a reciprocating internal combustion engine. The piston ring comprises a body having an outer circumferential surface. A tribological coating is formed on the outer circumferential surface of the body. The tribological coating has a dual layer structure and includes a relatively hard base layer and a relatively porous top layer overlying the base layer.

A piston assembly for an internal combustion engine includes a cylinder bore and a piston having a plurality of ring grooves, and a ring positioned within a ring groove. The ring includes a cross-section having a lower surface and an outer radial surface that form a scraping corner, an inner radial surface, and an upper surface. The upper surface and the lower surface are generally parallel with one another, and both upper and lower surfaces form a positive first angle with respect to a radial axis, and the outer radial surface forms a second positive angle with respect to a central axis. A constant twist occurs in the ring about a rotational center of the cross-section, the constant twist occurring at each cross-sectional location of the ring about the circumference of the ring and between adjacent free ends of the ring.

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Waterford, MI, United States of America

Fabio Mendes De Araujo