Abstract: A piston ring, and in particular a compression piston ring, has a running face, upper and lower flank regions, an inner circumferential surface and a joint, wherein at least the running face is provided with at least one wear-resistant PVD or CVD layer, wherein the PVD or CVD layer extends at a predefinable layer thickness across a circumferential length of more than 95%, but less than 100% of the piston ring, and defined circumferential sections are designed in a layer-free manner in the region of the joint.

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: The present invention is to provide a sealing device that has a small number of parts as three or less to achieve a more compact sealing device. The sealing device is combined an inner seal ring, an outer seal ring held in an outer circumferential holding groove of the inner seal ring, and a back ring. The outer seal ring satisfies a dimensional size relationship of T>A when T is the radial thickness dimension of the outer seal ring, G is the protrusion gap dimension, R is the radial width dimension of the chamfered sections on the edges of the open side of the seal installation groove, and A is the sum of the protrusion gap dimension G and the radial width dimension R of the chamfered sections on the edges of the open side.

Abstract: A piston seal includes an annular base portion, an inner circumferential lip portion protruding from an inner circumferential side of the base portion to come in sliding contact with an outer circumferential surface of the piston, an outer circumferential lip portion protruding from an outer circumferential side of the base portion to come in contact with the circumferential groove of the cylinder main body, and an intermediate protrusion portion protruding from between the inner circumferential lip portion and the outer circumferential lip portion of the base portion further than the outer circumferential lip portion. A connecting portion is formed to extend in an axial direction of the piston seal and is configured to connect the inner circumferential lip portion and the intermediate protrusion portion is formed between the inner circumferential lip portion and the intermediate protrusion portion.

Abstract: A seal housing is disposed to support an axially facing seal segment, and comprises a substrate and a coating. The substrate has an inner annular surface, an axially facing substrate surface, and a corner feature at an intersection of the inner annular surface and the axially facing substrate surface. The corner feature includes an annular notch in the inner annular surface, and a chamfer extending from the annular notch to the axially facing substrate surface. The coating is formed on the axially facing substrate surface and into the corner feature of the substrate, and has a coating surface, parallel to the axially facing substrate surface, that terminates at the inner annular surface and abuts the seal segment.

Abstract: A method of coating all surfaces of a plurality of piston rings in a single run by a chemical vapor deposition (CVD) process is provided. The method can include providing a coil formed of an iron-based material; heating the coil; and depositing a coating on all surfaces of the coil during a single continuous period of time, without having to move the coil during the CVD process. The coil is maintained in a fixed position during the depositing step. The method next includes splitting the coil into a plurality of separate coated piston rings. Alternatively, the method can include providing a plurality of stacked keystone piston ring bodies; and disposing a cylinder around the stack to maintain the keystone piston ring bodies in position while depositing the CVD coating on all surfaces of the keystone piston ring bodies during the single coating run.

Abstract: A piston ring having an outer running face, two flanks and an inner circumferential face is provided, the running face of which has profiling with a groove. The groove is arranged between two running face sections in relation to the cross section of the piston ring. The two running face sections are spaced apart from each other and substantially convexly curved and each have an apex. The groove has a periodically varying depth and a periodically varying width, and the number of periods of the course of the depth and the number of periods of the course of the width are equal.

Abstract: A seal groove is cut in the distal end face of a wrap of a fixed scroll, with a tip seal being fitted in the seal groove. Swelling members are interposed between both side faces of the tip seal and corresponding opposite side faces of the wrap. Condensed liquid of working medium w and water condensed from steam contained in the working medium w that are present between the tip seal and an end plate provide a sealing effect. When the swelling members swell upon absorbing the condensed liquids, they exert a strong pressing force on the tip seal and the wrap, thereby firmly retaining the tip seal in position. This prevents the tip seal from being pressed against the end plate, so that wear of the tip seal is reduced.

Abstract: A master-cylinder seal housed in a groove around a piston has a core connected to three annular and concentric lips. The core rests against a side of the groove and has: a surface provided with an interior edge followed by a peripheral platter cut by at least one channel, and an exterior crown provided with a connection zone formed by an interruption in the crown and deformable due to pressure within the seal to recreate the crown's continuity and impermeability while facilitating purging the brake system when there is no pressure in the channel and the connection zone.

Abstract: Apparatus for controlling a pressurized fluid. In accordance with some embodiments, a valve assembly includes a piston moved between closed and open positions. A sealing member is disposed within an annular recess of the piston and characterized as an endless annular ring extending about a central axis of the piston. The sealing member has an elongated circle cross-sectional shape when the sealing member is in an uncompressed state prior to installation in said recess. The cross-sectional shape is defined by parallel top and bottom surfaces having a length L in a direction perpendicular to and intersecting the central axis, and having opposing inner and outer surfaces of a radius R, the inner and outer surfaces respectively facing toward and facing away from the central axis, and wherein the dimensional value of L is at least five times greater than the dimensional value of R.

Abstract: A piston seal is provided in a circumferential groove formed in a cylinder body. The piston seal is capable of sealing a pressure chamber, which supplies fluid pressure to a discharge passage, from a supply passage, which communicates with a reservoir. The piston seal comprises: an annular base portion; an inner circumferential lip portion projecting from an inner circumferential side of the base portion and being in slidable contact with an outer circumferential surface of a piston; an outer circumferential lip portion projecting from an outer circumferential side of the base portion and being in abutment with the circumferential groove of the cylinder body; and an intermediate projecting portion which is formed between the inner circumferential lip portion and the outer circumferential lip portion of the base portion and which is projected beyond the outer circumferential lip portion. Cutout grooves are formed on a tip side of the intermediate projecting portion.

Abstract: A master cylinder (1) having a bore (3) fitted with at least one piston (4, 5) and at least one seal (19, 20, 21, 22). The seal (19, 20, 21, 22) is partially stiffened by a reinforcement member (25). In order to retain the piston (4,5) in the bore (3) a groove (31) is located on a circumference of the piston (4,5) against which the sealing member (25) bears with the piston (4,5) in a rest position to retain the piston (4,5) in bore (3).

Abstract: A piston ring having a stainless steel base material, the base material having an upper surface, a lower surface, an inner circumferential surface and an outer circumferential surface, the surfaces each having a nitride layer formed thereon, the nitride layer each first being formed to have a compound layer and a diffusion layer, the diffusion layer of the outer circumferential surface then being exposed by removing the compound layer of the outer circumferential surface, the exposed diffusion layer thereafter having an ion-plating deposition layer of hard ceramic formed thereon, the piston ring wherein the exposed diffusion layer is entirely removed on the upper and lower corners of the upper and lower surface and the outer circumferential surface by chamfering corner regions of the nitride layer located around the upper and lower corners before the ion-plating deposition layer is formed.

Abstract: A piston ring is made of martensitic stainless steel. Except for the outer circumferential surface of the piston ring, a nitrided layer having a Vickers hardness of 700 or more is formed on the upper and lower surfaces and inner circumferential surface, and a nitrided layer having a Vickers hardness of less than 700 is formed below the nitrided layer. A hard film is then formed by ion plating only on the outer circumferential surface of the piston ring. The hard film formed by ion plating and the nitrided layer with a Vickers hardness of 700 or more are separated without making contact in the vicinity of at least one of corner sections formed by the upper and lower surfaces and outer circumferential surface. The distance is within a range of 0.001 to 0.3 mm. The nitrided layers can be formed just on the upper and lower surfaces of the piston ring.

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 tank piston is shown with an improved seal and wiper. The piston is used in conjunction with tanks used for transporting semi-solid and viscous materials such as grease, oil, ink, and the like. The improved seal consists of an annular rubber member with a hollow chamber filled with an open cell foam material such as polyurethane, or a gel such as silica gel. The material in the chamber is compressible and expandable to provide a seal about the piston. Optionally, the piston is provided with an annular wiper structure that extends about the outer forward periphery of the piston, and is forwardly angled at about 45° relative to an axis of the piston. The wiper has a beveled end that makes contact with the interior surface of the tank to provide a cleaning action. A complementary second wiper may be added near the outer rearward periphery of the piston. A preferred embodiment is also shown that uses a tiered support assembly.

Abstract: A piston ring for use with ceramic matrix composite engine cylinders. In one embodiment, an extra-hard material is used for a conventional ring design. In another embodiment, a hardened edge employing Tungsten Carbide Cobalt is employed. The same edge treatment can also be employed for other seals such as that of a rotary engine.