Abstract: 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.

Abstract: 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.

Abstract: A three-part oil scraper ring includes an upper scraper ring (24), a lower scraper ring (26), wherein the scraper rings (24, 26) are held at a distance by an expander spring (34) and pressed radially outwards. The upper scraper ring (24) has a ring body (4) having an upper flank (6), a lower flank (8), a ring inner surface (10) and a ring outer surface (12) which has a ring outer contour (14) in cross-section in axial direction (A). The ring body (4) has a height H which, when viewed in axial direction (A), corresponds to the greatest distance of the upper flank (6) from the lower flank (8). The ring outer contour (14) forms a running surface (16) which has a radius of curvature R which is smaller than the height H of the upper scraper ring (24) by a factor between 1.5 to 6.

Abstract: An oil scraper ring is provided for pistons (2) of an internal combustion engine having an oil scraper piston ring groove (4) formed without at least one oil drain bore. The scraper ring includes a ring body (6) comprising an upper ring flank (8), a lower ring flank (10), a ring inner side (12), a ring outer side (14) and two abutting surfaces (16, 18). An upper oil scraper rail (20) and a lower oil scraper rail (22) extend in the circumferential direction in spaced apart relation from one another in the axial direction and extend radially to the outside from the ring outer side (14) are arranged on the ring outer side (14). Oil passages (24) running in the radial direction are arranged in a region between the upper scraper rail (20) and the lower scraper rail (22), and at least one groove (26) extends in the radial direction on the lower ring flank (10).

Abstract: A piston ring has a running surface, an inner surface, a lower ring flank, and an upper ring flank. A recess, extending across the perimeter in the shape of an internal angle, is located at the transition between the inner surface and the upper ring flank. The recess defines a conical first surface and a conical second surface at the piston ring. The first surface lies farther outward, when viewed in the radial direction, and farther above, when viewed in the axial direction, than the second surface. In an axial cross section, a first angle between the axial direction and the first surface lies in the range between 10° and 50°, and a second angle between the radial direction and the second surface lies in the range between 5° and 30°. A piston having a piston ring groove includes a projection on the groove bottom. A combination made from an above-mentioned piston ring and an above-mentioned piston are adapted to one another, so that the projection projects into the recess.

Abstract: A piston ring is provided, in particular a compression piston ring having at least one recess with a lower edge running obliquely to the upper piston ring flank on its upper piston ring flank, the ring flank extending radially outward from the piston ring interior and radially inward from the piston ring bearing surface. The piston ring has a chamfer, which is opposite at least one recess. At least one recess and the chamfer extend in the radial direction up to at most the center of the cross-sectional area of the piston ring.

Abstract: A piston ring has a running surface, an inner surface, a lower ring flank, and an upper ring flank. A recess, extending across the perimeter in the shape of an internal angle, is located at the transition between the inner surface and the upper ring flank. The recess defines a conical first surface and a conical second surface at the piston ring. The first surface lies farther outward, when viewed in the radial direction, and farther above, when viewed in the axial direction, than the second surface. In an axial cross section, a first angle between the axial direction and the first surface lies in the range between 10° and 50°, and a second angle between the radial direction and the second surface lies in the range between 5° and 30°. A piston having a piston ring groove includes a projection on the groove bottom. A combination made from an above-mentioned piston ring and an above-mentioned piston are adapted to one another, so that the projection projects into the recess.

Abstract: A three-part oil scraper ring includes an upper scraper ring (24), a lower scraper ring (26), wherein the scraper rings (24, 26) are held at a distance by an expander spring (34) and pressed radially outwards. The upper scraper ring (24) has a ring body (4) having an upper flank (6), a lower flank (8), a ring inner surface (10) and a ring outer surface (12) which has a ring outer contour (14) in cross-section in axial direction (A). The ring body (4) has a height H which, when viewed in axial direction (A), corresponds to the greatest distance of the upper flank (6) from the lower flank (8). The ring outer contour (14) forms a running surface (16) which has a radius of curvature R which is smaller than the height H of the upper scraper ring (24) by a factor between 1.5 to 6.

Abstract: A one-piece control ring with two stripping ridges and openings that extend from the outside of the ring to the inside is provided wherein the cross section of the ring body varies in the circumferential direction. This variation is achieved with internal grooves, the cross-sectional area of which decreases in the direction of the back of the ring, and with a variation of the depth of the groove lying between the ridges.

Abstract: A compression piston ring is provided, in particular a piston ring suitable as a second piston ring in a three-ring piston ring set, which piston ring has convex sections and concave sections alternating in the circumferential direction in a middle running face region in relation to the axial height, wherein the concave sections form profile recesses in the convexly crowned running face.

Abstract: An oil wiper ring is provided having two circumferential shoulders, the running surfaces whereof are outwardly curved, wherein the shoulder of the combustion chamber side has an axial height greater by at least a factor of 2 than the axial height of the shoulder on the crankcase side and wherein the should on the combustion chamber side has an asymmetrical crowning.

Abstract: A piston ring is provided, in particular a compression piston ring having at least one recess with a lower edge running obliquely to the upper piston ring flank on its upper piston ring flank, the ring flank extending radially outward from the piston ring interior and radially inward from the piston ring bearing surface. The piston ring has a chamfer, which is opposite at least one recess. At least one recess and the chamfer extend in the radial direction up to at most the center of the cross-sectional area of the piston ring.

Abstract: A compression piston ring 2 having a running-surface region 4, an upper flank 6, a lower flank 8 and also an inner circumferential surface 10, wherein the running-surface region 4 is provided with a profiled section, which, as viewed over the axial height of the running-surface region 4, comprises mutually spaced, convexly spherically constructed sections 12, 14 having an upper and lower apex So; Su, wherein a groove 16 with a depth Tn is arranged between the apexes So, Su, wherein both apexes So; Su are arranged below a centre M of the piston ring 2 in the axial direction.

Abstract: A piston ring (2) has at least one ring flank seal (14) arranged on a lower ring flank (8) of the piston ring.

Abstract: An oil wiper ring is provided having two circumferential shoulders, the running surfaces whereof are outwardly curved, wherein the shoulder of the combustion chamber side has an axial height greater by at least a factor of 2 than the axial height of the shoulder on the crankcase side and wherein the should on the combustion chamber side has an asymmetrical crowning.

Abstract: A one-piece control ring with two stripping ridges and openings that extend from the outside of the ring to the inside is provided wherein the cross section of the ring body varies in the circumferential direction. This variation is achieved with internal grooves, the cross-sectional area of which decreases in the direction of the back of the ring, and with a variation of the depth of the groove lying between the ridges.

Abstract: A compression piston ring is provided, in particular a piston ring suitable as a second piston ring in a three-ring piston ring set, which piston ring has convex sections and concave sections alternating in the circumferential direction in a middle running face region in relation to the axial height, wherein the concave sections form profile recesses in the convexly crowned running face.

Abstract: A piston ring (2) has at least one ring flank seal (14) arranged on a lower ring flank (8) of the piston ring.

Abstract: A piston ring for a piston of a piston engine has an external circumferential surface (2), and internal circumferential surface (4), and upper flank (6) pointing in the direction of the piston upper side, and a lower flank (8) pointing in the direction of the piston underside. The lower flank (8) runs obliquely with respect to the upper flank (6), so that axial height (A) of the piston ring is grater at the external circumferential surface (2) than the axial height (B) at the internal circumferential surface (4), and wherein on each side of the thrust of the piston ring at least one recess (10) is provided in the upper flank (6).

Abstract: A piston ring having an outer running face, two flanks and an inner circumferential face is provided. The running face has profiling. The profile of the running face is substantially convexly curved and has an apex. The axial position of the apex varies periodically in the circumferential direction.