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: Provided is a seal ring causing less friction and having a low oil leakage property even under a state in which a shaft rotation frequency or a housing rotation frequency is high, and being capable of reducing a shaft rotation torque. A level difference portion that forms a second width smaller than a first width is formed on a longitudinal sectional shape of the seal ring as viewed in a circumferential direction from a seal ring outer peripheral surface side toward a seal ring inner peripheral surface side.

Abstract: A three-piece oil control ring is provided for use in a piston groove of an internal combustion engine. The ring comprises a first annular segment and a second annular segment, associated to an expanding element. The expander has a substantially annular shape and comprises a first end facing the internal wall of the groove when the ring is mounted on the piston and a second opposite end. The ring further comprises an intermediate portion having at least one protrusion for association with the segments. Still further, the first end exhibits first thickness value (E1), the second end exhibits second thickness value (E2) and the substantially intermediate portion exhibits third thickness value (E3), wherein the value of (E1) is substantially lower than the value of (E3) and lower or similar to the value of (E2), the difference between (E1) and (E3) being substantially higher than that between (E1) and (E2).

Abstract: The invention relates to a piston ring comprising a slit forming a joint, a bearing surface, an inner peripheral surface, and upper and lower flanks extending thereinbetween. An inconstant cross-sectional interruption is provided in the region of the inner peripheral surface and, seen from the peripheral direction, is larger in the region of the joint than in the region which diametrically opposes the joint. The wall thickness of the inventive piston ring varies in the peripheral direction and is smaller in the region of the joint than in the region which diametrically opposes the joint. The relation between the wall thickness and the cross-sectional interruption is always such that the piston ring has a constant torsional angle, seen over the periphery.

Abstract: The invention relates to an oil scraper ring for pistons of internal combustion engines. The oil scraper ring comprises a disc that is provided with parallel flanks and a bearing surface having an asymmetrical crowned form with a vertex line extending over the periphery of the disc. A bracing spring arranged in a ring groove of the piston and comprising a spring groove side opposing the piston head and a spring groove side facing the piston head presses the disc radially against the friction and the abrasion of the bearing surface.

Abstract: A multipart oil wiping ring for pistons of internal combustion engines comprises two steel strip-type lamellae with parallel sides, the running surfaces of which are provided with a convexly asymmetric shape having a vertex line that extends across the circumference of the lamellae, and a bracing spring located between the lamellae. The bracing spring presses the lamellae in an axial direction against one respective side of an annular groove in the piston and in a radial direction against the cylinder wall.

Abstract: The invention relates to an oil scraper ring for pistons of internal combustion engines, said oil scraper ring comprising a disc (1) provided with a bearing surface (h) having an asymmetrical crowned form with a vertex line (3) extending over the periphery of the disc. Said disk (1) is arranged in a ring groove (7) of the piston and respectively has a ring groove side (6) opposing the piston head and a parallel ring groove side (5) facing the piston head. The aim of the invention is to achieve an improved oil scraping action compared to that of prior art, while reducing the friction and the abrasion of the bearing surface.

Abstract: A non-sealing, lubricating piston ring for lubricating the cylinder wall of a piston housing in a combustion tool is disclosed. The lubricating piston ring is made from a lubricating material such as polytetrofluroethylene (PTFE). The shape of the PTFE ring is designed to optimize the lubricity of the piston housing, while allowing enough friction for the piston to operate properly within the piston housing during reciprocating cycling movement. The PTFE ring may have radial fins extending from an outer surface thereof that are angled to promote ring rotations, such that the ring moves easily along and efficiently lubricates the inner cylinder wall of the piston housing. The PTFE ring does not form a seal between the piston and the housing. Instead, the PTFE ring is positioned above or below a sealing ring, such as a steel piston ring which forms the seal between the piston and the piston housing.

Abstract: The invention concerns a packing seal with its lip (1) placed in a toroidal housing (2) of a part (3) mobile in rotation and/or translation relatively to a part (4) and whereof the lip (5) ensuring the seal between the lining and the part (4) exerts on said part (4) an almost constant force whatever the pressure and whereof the support diameter can be maintained also almost constant whatever the temperature.

Abstract: A separating piston for a vibration damping system with a cylinder which is filled partly with damping fluid and partly with pressure gas and with a separating piston which is arranged in the cylinder and divides the pressure gas space from the fluid space in a sealing manner via a seal. The separating piston is guided in the cylinder by a guide, wherein the separating piston is provided with an additional guide between the seal and the end side facing the pressure gas space. A chamber which is open relative to the inner wall of the cylinder is arranged in the area between the seal and the additional guide.

Abstract: A piston ring being planar, having a dished section and a planform giving desired radial pressure distribution on a co-operating cylinder wall and which ring is made form a steel resistant to stress relieving at the piston ring operating temperature. The dishing may be either positive or negative and may lie in the range from 0.025 to 0.75 mm. A method and apparatus are also described for the manufacture of such rings.