Shaft sealing device, and rotary machine equipped therewith
A shaft sealing device and a rotary machine equipped therewith are provided with a sealing body configured by stacking a plurality of thin sealing pieces; and a low-pressure-side side sealing plate in which a plate surface facing the low-pressure side is pressed against an inner wall surface of the housing facing the direction of the axis by means of the pressure of a fluid applied from a high-pressure side to the low-pressure side. A protrusion for blocking a downward flow toward the inside of the low-pressure-side side sealing plate in the radial direction along the low-pressure side of the sealing body is formed on the inside of the low-pressure-side side sealing plate in the radial direction, and a communication path for guiding the downward flow blocked by means of the protrusion to a low-pressure-side region is formed on the housing.
1. A shaft sealing device to be provided in an annular space between a rotor and a stator surrounding an outer peripheral side of the rotor to divide the annular space into a low-pressure-side region and a high-pressure-side region in a direction of an axis of the rotor, the shaft sealing device comprising:
a housing to be fixed to the stator;
a sealing body including a plurality of thin sealing pieces stacked so as to extend toward a radially inward side of the rotor from the housing in a circumferential direction of the rotor; and
a high-pressure-side plate-shaped body and a low-pressure-side plate-shaped body positioned such that the sealing body is sandwiched between the high-pressure-side plate-shaped body and the low-pressure-side plate-shaped body from the direction of the axis of the rotor, wherein:
the low-pressure-side plate-shaped body is arranged along a low-pressure side of the sealing body and in which a surface facing the low-pressure side is pressed against an inner wall surface of the housing facing the direction of the axis by pressure of a fluid applied in operation from a high-pressure side to the low-pressure side,
a stemming portion adapted to block a flow of the fluid that is directed to the radially inward side along the low-pressure side of the sealing body is positioned adjacent the radially inward side of the low-pressure-side plate-shaped body,
the housing includes a communication path for guiding the flow of the fluid blocked by the stemming portion to the low-pressure-side region, wherein the communication path opens to the inner wall surface of the housing at an opening of one end thereof and opens to the low-pressure-side region at another end thereof, the communication path being located farther toward a radially outward side than the stemming portion,
the stemming portion is on a tip of the inner wall surface of the housing, and
the stemming portion is fixed to the housing such that a part of the stemming portion extends through the opening of the communication path.
2. The shaft sealing device according to claim 1 , wherein
the stemming portion includes a protrusion that protrudes toward the sealing body.
3. A rotary machine comprising:
the shaft sealing device according to claim 2 .
4. The shaft sealing device according to claim 1 , wherein
the communication path is one of a plurality of communication paths defined at intervals in the circumferential direction.
5. The shaft sealing device according to claim 4 , wherein
a groove portion that connects low-pressure-side openings in the plurality of communication paths to each other is defined in the inner wall surface of the housing.
6. A rotary machine comprising:
the shaft sealing device according to claim 5 .
7. A rotary machine comprising:
the shaft sealing device according to claim 4 .
8. A rotary machine comprising:
the shaft sealing device according to claim 1 .
9. The shaft sealing device according to claim 1 , wherein
a radial dimension of the low-pressure-side plate-shaped body is smaller than a radial dimension of the high-pressure-side plate-shaped body.
10. The shaft sealing device according to claim 1 , wherein
the stemming portion is J-shaped.
11. The shaft sealing device according to claim 1 , wherein
the stemming portion includes an arcuate section.
12. The shaft sealing device according to claim 11 , wherein
the part of the stemming portion that extends through the opening of the communication path is a first section of the stemming portion,
the arcuate section is a second section of the stemming portion,
the stemming portion includes a third section parallel to the first section, and
the arcuate section joins the first section to the third section.