A piston ring system for an internal combustion engine includes a first compression piston ring (2), a second compression piston ring (4), and an oil scraper piston ring (6). The first compression piston ring (2) has a first ring body (8) with a first upper ring flank (10), a first lower ring flank (12), a first ring inner side (14), a first ring outer side (16), as well as two first abutting surfaces. A first contact region (18) of the first ring body (8) is arranged with a cylinder running surface (20) above a first piston ring center (22). At least one first oil pocket (24) is arranged below the first contact region (18) in the circumferential direction. The second compression piston ring (4) having a second ring body (26) a second upper ring flank (28), a second lower ring flank (30), a second ring inner side (32), a second ring outer side (34), as well as two second abutting surfaces. A second contact region (36) of the second ring body (26) is arranged with the cylinder running surface (20) above or below a second piston ring center (38). At least one second oil pocket (40) is arranged below the second contact region (36) in the circumferential direction. The oil scraper piston ring (6) is formed in one piece, two pieces, or three pieces.

The present disclosure provides a sealing ring assembly having a ring and one or more gap cover elements, configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The ring may be segmented, and the gap cover elements may engage with interfaces between the ring segments. The gap cover elements are configured to move radially outward and wear as the ring wears. The gap cover elements may include, for example, wedge-shaped features that engage with corresponding wedge recesses in the interfaces. The sealing ring assembly may include a high-pressure boundary and a low-pressure boundary. As the sealing ring wears, the gap cover elements stay engaged with the interfaces, so that ring gaps do not form on the low pressure boundary.

The present disclosure provides a sealing ring assembly having a ring and one or more gap cover elements, configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The ring may be segmented, and the gap cover elements may engage with interfaces between the ring segments. The gap cover elements are configured to move radially outward and wear as the ring wears. The gap cover elements may include, for example, wedge-shaped features that engage with corresponding wedge recesses in the interfaces. The sealing ring assembly may include a high-pressure boundary and a low-pressure boundary. As the sealing ring wears, the gap cover elements stay engaged with the interfaces, so that ring gaps do not form on the low pressure boundary.

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.

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.

The present disclosure provides a sealing ring assembly having ring segments configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The sing segments are configured to move radially outward and wear during operation of the piston via the cylinder device. The ring segments include, for example, wedge-shaped features that engage with corresponding wedge recesses in the interfaces between ring segments. The sealing ring assembly may include a high-pressure boundary and a low-pressure boundary. As the sealing ring wears, the ring segments stay engaged with the interfaces, so that ring gaps do not form on the low pressure boundary.

The present disclosure provides a sealing ring assembly having ring segments configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The sing segments are configured to move radially outward and wear during operation of the piston via the cylinder device. The ring segments include, for example, wedge-shaped features that engage with corresponding wedge recesses in the interfaces between ring segments. The sealing ring assembly may include a high-pressure boundary and a low-pressure boundary. As the sealing ring wears, the ring segments stay engaged with the interfaces, so that ring gaps do not form on the low pressure boundary.

The present disclosure provides a sealing ring assembly having a ring and one or more gap cover elements, configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The ring may be segmented, and the gap cover elements may engage with interfaces between the ring segments. The gap cover elements are configured to move radially outward and wear as the ring wears. The gap cover elements may include, for example, wedge-shaped features that engage with corresponding wedge recesses in the interfaces. The sealing ring assembly may include a high-pressure boundary and a low-pressure boundary. As the sealing ring wears, the gap cover elements stay engaged with the interfaces, so that ring gaps do not form on the low pressure boundary.

The present disclosure provides a sealing ring assembly having a ring and one or more gap cover elements, configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The ring may be segmented, and the gap cover elements may engage with interfaces between the ring segments. The gap cover elements are configured to move radially outward and wear as the ring wears. The gap cover elements may include, for example, wedge-shaped features that engage with corresponding wedge recesses in the interfaces. The sealing ring assembly may include a high-pressure boundary and a low-pressure boundary. As the sealing ring wears, the gap cover elements stay engaged with the interfaces, so that ring gaps do not form on the low pressure boundary.

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.