Nok Corporation

Komatsu Corporation

Carl Freudenberg Kg

Freudenberg-nok General Partnership

Yoshiyuki Abe

Toshiyuki Maeda

Kenichi Ajiki

Yuhei Tabuchi

Yoshio Hoshino

Joel T Johnson

Hisatoshi Odaka

Noriyuki Matsui

Mathias Burkert

Takafumi Nakamura

Benjamin E Westbrook

Takeshi Wakana

A sealing device includes: an annular seal that is disposed on an outer periphery of a rod of a hydraulic cylinder further on a side of an extending direction than a cylinder head of the hydraulic cylinder and that has a pair of opposing first facing surfaces; a holding member disposed on an outer periphery of the seal; and a fixing member disposed on an outer periphery of the holding member, the fixing member having a tapered inner surface that contacts an outer surface of the holding member and that has an inner diameter increasing toward a retracting direction.

Sealing device

Object: To provide a sliding member with a low friction coefficient in which, when fine dents are formed in a surface of the sliding member by dimpling using a laser, no hard raised portions are generated, and which does not damage a mating member; and to provide a process for producing the sliding member. Solution Means: A sliding member comprising a polyamide resin and 10 to 50 wt % of a fibrous filler selected from the group consisting of carbon fibers, aramid fibers, and whiskers, and having fine dents formed in a sliding surface thereof by dimpling using a laser; and a process for producing a sliding member comprising adding 10 to 50 wt % of a fibrous filler selected from the group consisting of carbon fibers, aramid fibers, and whiskers to a polyamide resin, and forming fine dents in a sliding surface of the sliding member by dimpling using a laser.

Sliding member and process for producing the same

A seal system for a reciprocating cylinder includes a buffer seal, a rod seal, and a wiper seal. The buffer seal includes a dynamic seal lip and a static lip extending from a hinge portion. The hinge portion of the static lip allows fluid to escape past the outer diameter of the seal when the rod is retracted thereby releasing any pressure build-up between the rod seal and buffer seal. The axial face portion of the dynamic seal lip includes axially extending notches therein. The notches prevent the buffer seal from sticking to the axial wall of the groove and provide a consistent path for the fluid to energize the annular groove between the static and dynamic lips during the extension phase which is necessary for the function of the seal. The back-up ring is an integrated part of the buffer seal, used to provide superior extrusion resistance. The rod seal includes an annular seal body having a dynamic seal lip angularly extending radially inwardly and axially from the seal body, and a static lip angularly extending radially outwardly and axially from the seal body. An axial face portion of the dynamic seal lip and the static lip each include radially extending notches therein. The notches prevent the seal from sticking to the axial walls of the groove the rod seal is installed in and provides a consistent path for the fluid to energize the annular groove created by the static and dynamic lip during the extension phase. The back-up ring is an integrated part of the rod seal, used to provide superior extrusion resistance.

Wide range temperature and pressure hydraulic cylinder sealing system

A sealing system is provided which is intended to achieve an improvement in durability. A dust seal is composed of a first dust seal () and a second dust seal () which is arranged at a location nearer to an atmospheric air side than the first dust seal (), wherein each of the first dust seal () and the second dust seal () has a seal lip formed so as to be slidable with respect to an outer peripheral surface of the shaft. The first dust seal () has seal lips () made of urethane rubber, and the second dust seal () has only a single seal lip () which is made of a rubber higher in flexibility than urethane rubber, and which extends toward the atmospheric air side.

Sealing system

A sealing device in which a good lubricating oil film is formed along the entire circumference of a sliding surface. The sealing device () is fitted in an annular groove formed in either of two elements that are a housing having a shaft hole and a shaft inserted through the shaft hole, and the sealing device () seals an annular gap between the two elements. The sealing device () has a seal ring () sliding against the other element by relative axial movements of the two elements. In the seal ring (), on each of axially opposite ends of a sliding surface () sliding against the other element, there are formed grooves () extending from an end surface () of the seal ring () toward the axial center of a sliding surface ().

A sealing device is provided which is capable of reducing its sliding resistance. In a sealing devicewhich is fitted into an annular groove formed in one of a housing with a shaft hole and a shaft inserted into said shaft hole and serves to seal an annular gap between these two members, and which includes a seal ringmade of a resin that is in sliding contact with the other of the two members, and an elastic ringthat is fitted between the seal ringand the annular groove, the seal ring has a plurality of concave portionsformed on its sliding surfacewhich is in sliding contact with the other member.

Sealing device and production method thereof

A sealing system is provided which is intended to achieve an improvement in durability. A dust seal is composed of a first dust seal and a second dust seal which is arranged at a location nearer to an atmospheric air side than the first dust seal, wherein each of the first dust seal and the second dust seal has a seal lip formed so as to be slidable with respect to an outer peripheral surface of the shaft. The first dust seal has seal lips made of urethane rubber, and the second dust seal has only a single seal lip which is made of a rubber higher in flexibility than urethane rubber, and which extends toward the atmospheric air side.

A sealing device () having: a slide ring () and a back ring (). The sealing device () is configured to seal an annular gap between a housing having a shaft hole, and a shaft inserted through the shaft hole. The slide ring () has: a through-cut (), comprising a circumferential cut (A), and axial cuts (B) extending from both ends of the circumferential cut, along the axial direction; and multiple parting lines (A,B) formed on a surface of the slide ring (). The parting lines (A,B) are arranged so that the parting lines (A,B) are not overlapped with the circumferential cut (A) exposed at the junction surface of the slide ring () with the back ring (), throughout the lengthwise direction of the circumferential cut.

A sealing device in which a good lubricating oil film is formed along the entire circumference of a sliding surface. The sealing device () is fitted in an annular groove formed in either of two elements that are a housing having a shaft hole and a shaft inserted through the shaft hole, and the sealing device () seals an annular gap between the two elements. The sealing device () has a seal ring () sliding against the other element by relative axial movements of the two elements. In the seal ring (), on each of axially opposite ends of a sliding surface () sliding against the other element, there are formed grooves () extending from an end surface () of the seal ring () toward the axial center of a sliding surface (). Further, in the seal ring (), the boundary between each groove () and the sliding surface () is formed only by lines inclined relative to the direction of sliding of the sliding surface (), and grooves () are circumferentially adjacently arranged in the seal ring () so that regions each having the boundary formed by the inclined lines are continuous along the entire circumference of the sliding surface ().

The hydraulic cylinder having a portion on a side of a lip tip end of an annular clearance between an inner circumferential face of a shaft hole of a cylinder and a piston is made up of a minute clearance in order to suppress protrusion of the lip, wherein an annular clearance area for suppressing occurrence of the cavitation and for shortening an axial distance of the annular clearance portion made up of the minute clearance is formed on an opposite side of the annular clearance portion from a mounting groove.

Hydraulic cylinder

A hydraulic cylinder includes a cylinder having a shaft hole, a piston inserted into the shaft hole so as to have clearance with respect to an inner circumferential surface of the shaft hole, and seal members arranged in annular grooves formed in an inner circumference of the shaft hole to seal an annular gap between the inner circumference of the shaft hole and the piston, wherein in the hydraulic cylinder in which cavitation could occur in a portion of the clearance accompanying motion of the piston, an expansion part obtained by expanding a portion of a sidewall surface of the annular grooves on an inner circumferential edge side outward from an arrangement area of the seal members is provided to make a distance from a location where cavitation occurs to the seal members longer by a space formed by the expansion part.

In the manufacture of a seal ring having a cut portion at one position on the circumference by injecting a molten molding material from a gate into a cavity of a forming die, the gate is provided at a position apart from the opposite position to the cut portion of the seal ring. In the case of a seal ring with a weld portion, the weld portion is set away from the cut portion.

Resin seal ring die with various mold cut portions

In the manufacture of a seal ring having a cut portion at one position on the circumference by injecting a molten molding material from a gate into a cavity of a forming die, the gate is provided at a position apart from the opposite position to the cut portion of the sealing. In the case of a seal ring with a weld portion, the weld portion is set away from the cut portion.

Seal ring and method of manufacturing the same

In the manufacture of a seal ring having a cut portion at one position on the circumference by injecting a molten molding material from a gate into a cavity of a forming die, the gate is provided at a position apart from the opposite position to the cut, portion of the seal ring. In the case of a seal ring with a weld portion, the weld portion is set away from the cut portion.

Growing community of inventors

Nihonmatsu, Japan

Yoshiyuki Abe