Shaft sealing structure

A shaft sealing structure arranged between a rod configured to be driven within a predetermined fluid and move in an axial direction, and a holder in which the rod is accommodated, the shaft sealing structure comprising:

• a plurality of U-packings stacked in multiple stages, wherein
• each of the plurality of U-packings is formed of a top portion formed to be thick-walled and having an annular shape, an inner side skirt portion formed to be thin-walled and extending inwardly and in an axial direction from the top portion, and an outer side skirt portion formed to be thin-walled and extending outwardly and in the axial direction from the top portion,
• the inner side skirt portion includes a rib configured to slidably contact an outer surface of the rod, and the outer side skirt portion includes a rib configured to abut against an inner surface of the holder,
• in adjacent ones of the plurality of U-packings, the top portion of one of the adjacent U-packings and the top portion of another of the adjacent U-packings abut against each other, the inner side skirt portion of the one of the adjacent U-packings and the inner side skirt portion of the other of the adjacent U-packings do not interfere with each other, and the outer side skirt portion of the one of the adjacent U-packings and the outer side skirt portion of the other of the adjacent U-packings do not interfere with each other,
• the U-packings are made of a fluorine resin,
• a first guide bush and a second guide bush, both of said guide bushes being configured to guide the rod in a manner that the rod is movable in the axial direction is attached to the holder,
• a scraper is mounted between a pressing plate attached to the holder and the first guide bush, and the plurality of ti-packings are mounted between the scraper and the first guide bush, and
• an auxiliary packing made of rubber mounted between the first guide bush and the second guide bush.

A valve adopting a shaft sealing structure arranged between a rod configured to be driven within a predetermined fluid and move in an axial direction, and a holder in Which the rod is accommodated, the shaft sealing structure including:

• a plurality of V-packings stacked in multiple stages, wherein
• each of the plurality of V-packings is formed of a top portion formed to be thick-walled and having an annular shape, an inner side skirt portion formed to be thin-walled and extending diagonally inward from the top portion, and an outer side skirt portion formed to be thin-walled and extending diagonally outward from the top portion,
• the inner side skirt portion slidably contacts an outer surface of the rod at a distal end of the inner side skirt portion, and the outer side skirt portion abuts against an inner surface of the holder at a distal end of the outer side skirt portion,
• in adjacent ones of the plurality of V-packings, the top portion of one of the adjacent V-packings and the top portion of another of the adjacent V-packings abut against each other, the inner side skirt portion of the one of the adjacent V-packings and the inner side skirt portion of the other of the adjacent V-packings do not interfere with each other, and the outer side skirt portion of the one of the adjacent V-packings and the outer side skirt portion of the other of the adjacent V-packings do not interfere with each other,
• the V-packings are made of a fluorine resin,
• a first guide bush and a second guide bush, both of said guide bushes being configured to guide the rod in a manner that the rod is movable in the axial direction is attached to the holder, and
• a scraper is mounted between a pressing plate attached to the holder and the first guide bush, and the plurality of V-packings are mounted between the scraper and the first guide bush, and
• an auxiliary packing made of rubber mounted between the first guide bush and the second guide bush.

A valve adopting a shaft sealing structure arranged between a rod configured to be driven within a predetermined fluid and move in an axial direction, and a holder in which the rod is accommodated, the shaft sealing structure including:

• a plurality of U-packings stacked in multiple stages, wherein
• each of the plurality of U-packings is formed of a top portion formed to be thick-walled and having an annular shape, an inner side skirt portion formed to be thin-walled and extending inwardly and in an axial direction from the top portion, and an outer side skirt portion formed to be thin-walled and extending outwardly and in the axial direction from the top portion,
• the inner side skirt portion includes a rib configured to slidably contact an outer surface of the rod, and the outer side skirt portion includes a rib configured to abut against an inner surface of the holder,
• in adjacent ones of the plurality of U-packings, the top portion of one of the adjacent U-packings and the top portion of another of the adjacent U-packings abut against each other, the inner side skirt portion of the one of the adjacent U-packings and the inner side skirt portion of the other of the adjacent U-packings do not interfere with each other, and the outer side skirt portion of the one of the adjacent U-packings and the outer side skirt portion of the other of the adjacent U-packings do not interfere with each other,
• the U-packings are made of a fluorine resin,
• a first guide bush and a second guide bush, both of said guide bushes being configured to guide the rod in a manner that the rod is movable in the axial direction is attached to the holder, and
• a scraper is mounted between a pressing plate attached to the holder and the first guide bush, and the plurality of U-packings are mounted between the scraper and the first guide bush, and
• an auxiliary packing made of rubber mounted between the first guide bush and the second guide bush.