Nok Corporation

Advics Co., Ltd.

Hiroaki Monma

Takahiro Yamaguchi

Yosuke Kondo

Nobuhiko Yoshioka

Shuji Yoshitsune

Hikaru Tadano

Kota Henmi

Mitsuo Watanabe

Daisuke Matsumoto

A sealing device capable of preventing, when a shaft and a housing move relative to each other, the sealing device from moving together with the shaft. A resin seal ringincludes a cylindrical section, a pair of inner circumference lipsrespectively provided on both sides of the cylindrical sectionin the axial direction, a pair of outer circumference lipsrespectively provided on both sides of the cylindrical sectionin the axial direction, and an annular mounting groovewhich is provided on an outer circumference surface of the cylindrical sectionand in which the elastic seal ringis mounted. The pair of inner circumference lipsare configured to slide on an outer circumference surface of the shaft. The pair of outer circumference lipsare configured to be in close contact with the inner circumference surface of the shaft hole.

Sealing device

A sealing structure suppresses possible damage to a seal ring because of a backup ring. The sealing structure is characterized in that a cut portionthat is cut in a planar shape is formed in a backup ringat one position in a circumferential direction, the cut portionis configured such that a cut surfaceis oblique to a central axis of the backup ring, an acute angle of angles between a surface on the high pressure side of the backup ringand the cut surfaceis set to not less than 15&#xb0; and not more than 30&#xb0;, and the backup ringis formed of a resin material having Rockwell hardness of 100 or less, durometer hardness of 70 or less, and elastic modulus of 1.0 GPa or less.

Sealing structure

An object is to provide a backup ring manufacturable with an angle of a cut portion set to a standard cut angle even in the case of a product having a small diameter etc. due to dimensional limitation of a device used therewith, and is solved by a sealing device characterized in that a backup ringis disposed in an annular gapformed by disposing a sloped surfaceon a member surface of one of two members, i.e., a shaftand a housinghaving a shaft hole in which the shaftis inserted, with a distance from a counterpart member gradually reduced from a high pressure side toward a low pressure side, that the backup ringis in contract with the sloped surfaceon the low pressure side relative to a mounted seal membermade of an annular elastic member, that the backup ringhas an axially extending cylindrical portionand a projecting portioncontinuously disposed on an end portion of the cylindrical portionon the high pressure side and formed to annularly project in a radial direction from the end portion toward the sloped surface, and that the projecting portionhas a radial tip surface made up of a taper surfacefacing the sloped surface

A sealing device () includes a resinous sealing ring () and an elastomeric elastic ring () in an annular groove. The sealing ring () has a cylindrical surface portion () making intimate contact with a groove bottom of the annular groove () and an inclined surface portion () expanding in diameter toward the atmosphere side (A). The elastic ring () is disposed such that at least its portion is compressed between the inclined surface portion () and the groove bottom of the annular groove () so as to press a portion of the sealing ring () on the atmosphere side (A) toward the outer peripheral side.

In a sealing device installed to an installation groove which is provided in an outer peripheral surface of one member among two members relatively moving, and sealing between the two members by coming into close contact with the other member which is positioned in an outer peripheral side of the installation groove and one side wall of the installation groove, the sealing device has a seal ring, a support ring having a pressing surface which comes into contact with an inner peripheral corner portion the seal ring, and a spring means which presses the support ring and the seal ring. A collapsing margin in relation to the taper surface shaped pressing surface in the support ring is normally set in an inner peripheral corner portion in the seal ring. According to the sealing device, it is possible to improve pressure resistance and sealing performance.

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Fujisawa, Japan

Hiroaki Monma