Abstract: A plurality of concave portion to be spaced apart from each other in a circumferential direction through a pillar portion is formed in an inner circumferential side of a side surface of a seal ring mounted in a shaft groove formed in an outer circumferential surface of a shaft. The concave portion including a deepest portion, and two inclined portions, connects the inclined portion positioned at an opposite side in a rotational direction and the adjacent pillar portion with a curved surface having a shape convex, and further, makes a width in the circumferential direction of the inclined portion of the rotational direction side smaller than a width in the circumferential direction of the inclined portion of the opposite side in the rotational direction.

Abstract: Provided is a seal ring that has low-leakage characteristics and low-friction characteristics and can improve the drive loss of the automatic transmission of an automobile to thereby contribute to an improvement in the fuel consumption of the automobile. The seal ring is attached to a shaft groove formed on the outer peripheral surface of a shaft. A plurality of peripherally spaced recessed sections are formed on at least the inner peripheral side of a contact side-surface. Inner walls are provided on the inner peripheral side of the recessed sections, and oil introduction openings that open on an inner peripheral surface are provided on the inner peripheral side of the recessed sections. The inner walls may be provided on opposite peripheral sides of the recessed sections but may be provided only on the rear side in the rotation direction.

Abstract: Provided is a seal ring which has low-friction characteristics and low-leakage characteristics, reduces drive loss of the automatic transmission of an automobile, and contributes to improvement in fuel consumption of the automobile. The seal ring is attached to a shaft groove on the outer peripheral surface of a shaft. A plurality of recessed sections circumferentially spaced apart from each other with pillar sections interposed therebetween are formed at least on the inner peripheral side of a side surface of the seal ring in contact with the shaft groove. The circumferential opposite ends of each of the recessed sections are formed as squeezing portions formed of curved surfaces convex toward the pillar sections. The depth “h” of a deepest portion in which the axial width of the recessed section is the largest is set in the range of 2 to 17 where the axial width of the seal ring is 100.

Abstract: A plurality of concave portion to be spaced apart from each other in a circumferential direction through a pillar portion is formed in an inner circumferential side of a side surface of a seal ring mounted in a shaft groove formed in an outer circumferential surface of a shaft. The concave portion including a deepest portion, and two inclined portions, connects the inclined portion positioned at an opposite side in a rotational direction and the adjacent pillar portion with a curved surface having a shape convex, and further, makes a width in the circumferential direction of the inclined portion of the rotational direction side smaller than a width in the circumferential direction of the inclined portion of the opposite side in the rotational direction.

Abstract: Provided is a seal ring which has low-friction characteristics and low-leakage characteristics, reduces drive loss of the automatic transmission of an automobile, and contributes to improvement in fuel consumption of the automobile. The seal ring is attached to a shaft groove on the outer peripheral surface of a shaft. A plurality of recessed sections circumferentially spaced apart from each other with pillar sections interposed therebetween are formed at least on the inner peripheral side of a side surface of the seal ring in contact with the shaft groove. The circumferential opposite ends of each of the recessed sections are formed as squeezing portions formed of curved surfaces convex toward the pillar sections. The depth “h” of a deepest portion in which the axial width of the recessed section is the largest is set in the range of 2 to 17 where the axial width of the seal ring is 100.

Abstract: A combined piston ring comprising a special gap effective for reducing blowby to have excellent gas sealability, comprising a piston ring body of a high-strength, heat-resistant resin comprising a step-shaped gap exposed on upper and lower side surfaces and an outer peripheral surface, and a spring disposed on the inner peripheral side of the piston ring body for pushing the piston ring body radially outward, at least a side surface of the piston ring body on the combustion chamber side having a heat-resistant coating, whereby the side surface of the piston ring on the combustion chamber side is not subject to local deformation and melting by a burned gas from the combustion chamber.

Abstract: Provided is a seal ring that has low-leakage characteristics and low-friction characteristics and can improve the drive loss of the automatic transmission of an automobile to thereby contribute to an improvement in the fuel consumption of the automobile. The seal ring is attached to a shaft groove formed on the outer peripheral surface of a shaft. A plurality of peripherally spaced recessed sections are formed on at least the inner peripheral side of a contact side-surface. Inner walls are provided on the inner peripheral side of the recessed sections, and oil introduction openings that open on an inner peripheral surface are provided on the inner peripheral side of the recessed sections. The inner walls may be provided on opposite peripheral sides of the recessed sections but may be provided only on the rear side in the rotation direction.