JP3310049B2 - Shaft sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft sealing device and, more particularly, to a shaft sealing device for preventing water leakage from a rotating shaft of a hydraulic machine such as a water turbine or a pump turbine.

[0002]

2. Description of the Related Art Generally, a hydraulic machine such as a water turbine or a pump turbine is provided with a shaft sealing device for preventing pressurized water around a runner directly connected to a main shaft from leaking from the main shaft to the outside. This type of shaft sealing device is disclosed in, for example,
Japanese Patent Application Laid-Open Nos. 80173, 62-237172 and 64-80773.

FIG. 5 shows a typical example of the shaft sealing device disclosed in the above-mentioned publication. In the vicinity of an upper part of a runner directly connected to a main shaft 1 of a hydraulic machine, a flange 2 protrudes from the main shaft 1. Have been. A rotating side seal ring 5 is attached to the flange 2 via a metal ring 3 and an attachment 4. A housing 6 is arranged to surround the flange 2, and a cover 7 and an O
A seal case 9 is arranged via the ring 8.
A stationary seal ring 12 is attached to the seal case 9 via a metal ring 10 and an attachment 11. A spring 13 is mounted between the cover 7 and the seal case 9, and the spring 13 is connected to the seal surface 12 a of the stationary side seal ring 12 via the seal case 9.
Is pressed against the sealing surface 5 a of the rotating side seal ring 5.

Each of the rotating side seal ring 5 and the stationary side seal ring 12 has a plurality of seal ring pieces 105 and 112 as shown in FIG. 6 due to the necessity of disassembling and assembling the shaft sealing device.
It is composed of The seal ring pieces 105, 1
As the twelfth material, a ceramic material such as silicon carbide has recently been used in addition to conventional calcined carbon. In this shaft sealing device, leakage of pressurized water on the runner side is prevented by the seal rings 5, 12 and the O-ring 8 on the rotating and stationary sides.

[0005]

In order to eliminate the above-mentioned boundary step, the sealing surfaces 5a, 112 are fixed to the metal rings 3, 10 while the sealing ring pieces 105, 112 are fixed to the metal rings 3, 10.
A method of processing 12a is also conceivable. However, if a part of the seal ring pieces 105 and 112 is damaged or missing during operation, this method replaces both the damaged seal ring piece and the metal ring holding the seal ring piece. Another problem is that it is necessary to prepare a set of seal ring pieces and a metal ring as spare parts at all times in order to restart the machine early. appear. Further, the springs 13 are used for sealing surfaces 5a, 12a generated in a normal operation state.
Has the function of absorbing fluctuations in the direction perpendicular to the direction. However, the spring 13 cannot follow high-cycle minute vibrations generated in an unstable rotation state such as a transient operation state or the like. , 112 may be damaged. Further, since the seal ring pieces enhance the water sealing performance, there is almost no gap between adjacent seal ring pieces. Accordingly, when frictional heat is generated on the sealing surface with the rotation of the rotating side seal ring 5, thermal stress due to thermal expansion is generated in the seal ring in the circumferential direction. This thermal stress may also cause the seal ring pieces 105 and 112 to crack or drop.

Further, when the water turbine is operated at a high pressure and a high speed during normal operation, the seal ring is worn, cracked or chipped due to frictional heat of the sealing surface, that is, the sliding surface. In particular, during the idle operation of the pump turbine in the pumping standby state, or during the phase adjustment operation of the turbine and the pump turbine, since only air exists around the seal surface of the seal ring and no water exists, the seal surface is extremely hot. There is a problem that wear, cracks, chipping and the like are remarkably generated, and the water sealing performance is significantly reduced. In addition, during long-term use, foreign matter such as earth and sand mixed into the pressurized water passes through the seal ring and gradually accumulates between the seal ring and the main shaft, which also lowers the water sealing performance. There is also a problem.

Accordingly, an object of the present invention is to provide a shaft seal device capable of suppressing the generation of frictional heat of a seal ring during idling operation or phase adjustment operation of a hydraulic machine, thereby preventing cracks or missing of the seal ring. Is to provide.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a flange protruding from a rotating shaft, a housing disposed so as to surround the flange, a seal case disposed in the housing, and a flange. A rotating-side seal ring, which is composed of a plurality of seal ring pieces that are attached and circumferentially arranged adjacent to each other, and attached to the seal case so as to be pressed against the rotating-side seal ring, and arranged adjacently in the circumferential direction. A water seal housing provided inside the housing, and a rotating side and a stationary side seal ring. A plurality of water supply holes formed along a circumferential direction on a wall surface of the water supply housing at a position opposed to a sealing surface; , During idle operation or adjustment phase operation of the hydraulic machine, and is characterized in that the water supply from the water supply hole to the sealing surface of the seal ring of the rotary side and the stationary side.

In this configuration, it is desirable to provide a water supply hole perforated in the seal case and for supplying water between the rotary ring and the stationary side seal ring and the rotary shaft. The housing and the water supply hole of the seal case are preferably supplied with water from a runner seal water supply system of the hydraulic machine. In addition, it is desirable that the water supply pressure from the water supply housing is higher than the water supply pressure from the water supply hole of the seal case. Also, the present invention provides a flange protruding from a rotating shaft, a housing disposed to surround the flange, a seal case disposed in the housing, and a peripheral case attached to the flange and circumferentially attached to the flange. A rotating side seal ring composed of a plurality of disposed seal ring pieces, and a plurality of seal ring pieces attached to the seal case so as to be pressed against the rotational side seal ring and arranged adjacently in the circumferential direction. Wherein at least one of the rotating side seal ring and the stationary side seal ring has a first circumferential direction extending circumferentially on a sealing surface thereof. A groove is formed, and a first water supply hole for supplying water to the first circumferential groove is formed in the seal case and the stationary side seal ring. Than it is.

In this configuration, at least one of the rotating side seal ring and the stationary side seal ring is provided with a second circumferential groove extending in a circumferential direction on a sealing surface thereof. A second water supply hole is provided in the seal case and the stationary side seal ring, and is provided with a second water supply hole for supplying water to the second circumferential groove. A first radial groove extending from the first circumferential groove to an outer peripheral end of the seal ring and a second radial groove extending from the second circumferential groove to an inner peripheral end of the seal ring are respectively formed. It is desirable to be installed. On the sealing surface between the rotating side seal ring and the stationary side seal ring, small gaps are respectively formed on the outer peripheral side with respect to the first circumferential groove and on the inner peripheral side with respect to the second circumferential groove. Is preferred.

[0011]

According to the present invention, the water supply housing supplies water from the water supply holes to the sealing surfaces of the rotating and stationary seal rings during the idling operation or the phase adjustment operation of the hydraulic machine.
As a result, the sealing surfaces of the rotating side and stationary side sealing rings are lubricated and cooled, the generation of frictional heat on the sealing surfaces is sufficiently suppressed, and wear, cracks and missing of the sealing rings can be prevented. Further, in the present invention, water is supplied to the first circumferential groove through the first water supply hole when the rotation shaft rotates. The water supplied to the first circumferential groove is
Lubricate and cool the sealing surfaces of the rotating and stationary seal rings. As a result, the generation of frictional heat on the sealing surface is sufficiently suppressed, and wear, cracks, and missing of the seal ring can be prevented. Further, by discharging the cooling water to the inner peripheral side of the seal ring, foreign matters such as earth and sand accumulated between the seal ring and the rotating shaft can be discharged.

[0012]

FIG. 5 shows an embodiment of a shaft sealing device according to the present invention.
6 and FIG. 6 will be described with reference to FIGS.

FIGS. 1 and 2 show a first embodiment of the present invention. 1 and 2, the housing 6
Is provided with a ring-shaped water supply housing 27, and a plurality of water supply holes 28 are formed in the wall of the water supply housing 27 along the circumferential direction. These water supply holes 28 face the sealing surfaces 16a and 19a, and are located at substantially the same height. In the water supply housing 27,
A water supply pipe 29 is connected. A water supply hole 30 is formed in the seal case 9, and the water supply hole 30 is
Water is supplied to the space between 6, 19 and the rotating shaft 1.

Next, the operation of this embodiment will be described. The water supply pipe 29 supplies water to the water supply housing 27 at the time of idling operation or phase adjustment operation of the hydraulic machine, whereby the water supply hole 28 is provided.
Discharges cooling water to the sealing surfaces 16a, 19a of the sealing rings 16, 19 rotating in the air. The cooling water lubricates and cools the sealing surfaces 16a and 19a, thereby suppressing the generation and wear of frictional heat on the sealing surfaces.

The water supply hole 30 of the seal case 9 is also provided with the seal rings 16, 1 during idling operation or phase adjustment operation of the hydraulic machine.
Cooling water is supplied to a space between the rotary shaft 9 and the rotating shaft 1. In this space, staying water is generally present, and the staying water is stirred by the rotation of the rotating shaft 1 and the temperature rises.
19 is heated. The cooling water from the water supply hole 30 cools the stagnant water and suppresses the temperature rise of the seal rings 16 and 19. The water supply hole 30 of the seal case 9 supplies water to the space between the seal rings 16, 19 and the rotating shaft 1 during normal operation, idle operation, or phase adjustment operation of the hydraulic machine,
Foreign matter such as earth and sand deposited in this space is eliminated. The water supply pressure from the water supply housing 27 is set to be larger than the water supply pressure from the water supply hole 30 of the seal case 9.

The water supply source of the water supply housing 27 and the water supply source of the water supply hole 30 can be a water supply source branched from a runner seal water supply system used during idling operation or phase adjustment operation of the hydraulic machine. . In this case, if necessary, a water supply source, a water supply housing 27 and a water supply hole 30 are provided.
It is preferable to connect a pressure reducing valve or the like between them. 3 and 4 show a second embodiment of the present invention. 3 and 4
, The rotating and stationary seal rings 16, 19
The circumferential surfaces 3a on the outer peripheral side are
1 and a circumferential groove 32 on the inner circumferential side are respectively carved. A radial groove 33 is connected to the outer circumferential groove 31, and the radial groove 33 extends from the outer circumferential groove 31 to the outer circumferential ends of the seal rings 16 and 19. Similarly, a radial groove 34 is connected to the inner circumferential groove 32, and the radial groove 34 extends from the inner circumferential groove 32 to the inner circumferential ends of the seal rings 16 and 19. I have.

The seal case 9 and the stationary side seal ring 1
9, a plurality of water supply holes 35 and 36 are respectively formed, and these water supply holes 35 communicate with the circumferential groove 31 on the outer peripheral side, and the water supply hole 36 communicates with the circumferential groove 32 on the inner peripheral side. I have. The sealing surfaces 16a and 19a have circumferential grooves 3 on the outer circumferential side.
1 to the outer circumferential end of the sealing surface and the circumferential groove 3 on the inner circumferential side
A slight gap δ4 is formed from No. 2 to the inner peripheral end of the sealing surface.

The other structure is the same as that of the first embodiment. The operation of this embodiment is as follows. Water supply hole 3
Reference numerals 5 and 36 supply the cooling water to the outer circumferential groove 31 and the inner circumferential groove 32, respectively, during normal operation, idle operation, and phase adjustment operation of the hydraulic machine. The cooling water flowing into the circumferential groove 31 on the outer circumferential side lubricates and cools the seal faces 16a and 19a, and flows out to the outer circumferential end of the seal face through the radial groove 33 and the gap δ4. The cooling water that has flowed into the circumferential groove 32 on the inner circumferential side lubricates and cools the seal faces 16a and 19a, and flows out to the inner circumferential end of the seal face through the radial groove 34 and the gap δ4. The cooling water flowing out from this inner peripheral end
The stagnant water staying between the seal rings 16 and 19 and the rotating shaft 1 is cooled, and foreign matters such as earth and sand deposited there are discharged. The circumferential grooves 31 and 32 on the outer peripheral side and the inner peripheral side are used.
When the cooling water is supplied to, the surface pressure of the sealing surfaces 16a and 19a decreases. In this case, when supplying the cooling water, the spring 13 shown in FIG.
a, the surface pressure of 19a can be adjusted to be constant. Further, the water supply sources of these water supply holes 35 and 36 can be branched from the runner seal water supply system as in the first embodiment. Also in this case, if necessary, a pressure reducing valve or the like is installed, and the water pressure of the water supply source is reduced to a predetermined value so that the water supply holes 35, 3
6 can also be supplied. Furthermore, the radial grooves 33, 3
Instead of 4, a groove inclined in the direction opposite to the rotation direction of the rotation side seal ring 16 may be carved, whereby stable water sealing performance can be always obtained.

[0019]

According to the present invention, during the idling operation or the phase adjustment operation of the hydraulic machine, the water supply housing supplies water from the water supply holes to the sealing surfaces of the seal rings on the rotating side and the stationary side, and the rotation side and the rotating side. Since the seal surface of the stationary seal ring is lubricated and cooled, the generation of frictional heat on the seal surface can be sufficiently suppressed, and wear, cracks and missing of the seal ring can be prevented.

Further, according to the present invention, the cooling water supplied to the first circumferential groove through the first water supply hole lubricates and cools the sealing surfaces of the rotating and stationary seal rings. In addition, the generation of frictional heat on the sealing surface can be sufficiently suppressed, and wear, cracks, and missing of the seal ring can be prevented.
Further, by discharging the cooling water to the inner peripheral side of the seal ring, foreign matters such as earth and sand accumulated between the seal ring and the rotating shaft can be discharged.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a first embodiment of a shaft sealing device according to the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the first embodiment.

FIG. 3 is a sectional view showing a second embodiment of the shaft sealing device according to the present invention.

FIG. 4 is an enlarged plan view showing a rotating side seal ring of a second embodiment.

FIG. 5 is a sectional view showing a conventional shaft sealing device.

FIG. 6 is a cross-sectional view showing a rotating side seal ring piece of a conventional shaft sealing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary shaft (spindle) 2 Flange 6 Housing 9 Seal case 14 Seal ring holding member 16 Rotating side seal ring 17 Seal ring holding member 19 Stationary side seal ring 26 Step part of seal ring 27 Water supply housing 28 Water supply hole 30 Water supply hole 31 first circumferential groove (outer circumferential groove) 35 water supply hole

Continuation of the front page (56) References JP-A-63-163073 (JP, A) JP-A-6-81761 (JP, A) JP-A-5-79446 (JP, A) JP-A-3-57566 (JP) , U) Japanese Utility Model Application Hei 3-89273 (JP, U) Japanese Utility Model Application Hei 4-73660 (JP, U) Japanese Utility Model Application Hei 6-18766 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) F16J 15/28 F03B 11/06

Claims (2)

(57) [Claims] 1. A flange protruding from a rotating shaft, a housing arranged to surround the flange, a seal case arranged in the housing, and attached to the flange and arranged adjacently in a circumferential direction. A rotating-side seal ring composed of a plurality of seal ring pieces, and a plurality of seal ring pieces that are attached to the seal case so as to be pressed against the rotational-side seal ring and are arranged adjacently in the circumferential direction. A shaft sealing device for a hydraulic machine comprising a stationary seal ring configured as described above, wherein: a water supply housing provided inside the housing; and a water supply housing facing a sealing surface of the rotating side and stationary side seal rings. A plurality of water supply holes formed along a circumferential direction on a wall surface of the water supply housing; a plurality of water supply holes; A water supply hole for supplying water to a space between the water supply housing and the water supply hole, the idle side or the phase-adjustment operation of the hydraulic machine, the rotation side and the stationary side from the water supply hole and the water supply hole. A shaft seal device for supplying water to a seal surface of a seal ring. 2. A flange protruding from a rotating shaft, a housing disposed so as to surround the flange, a seal case disposed in the housing, and affixed to the flange and disposed adjacently in a circumferential direction. A rotating-side seal ring composed of a plurality of seal ring pieces, and a plurality of seal ring pieces that are attached to the seal case so as to be pressed against the rotational-side seal ring and are arranged adjacently in the circumferential direction. A shaft sealing device comprising a stationary seal ring configured as described above, wherein at least one of the rotating seal ring and the stationary seal ring has a first circumferential groove extending circumferentially on a sealing surface thereof. And a first radial groove extending from the first circumferential groove to the outer peripheral end of the seal surface is formed, and the first seal groove is formed between the rotating seal ring and the stationary seal ring. At least one of the second circumferential grooves extends on the inner circumferential side of the first circumferential groove of the seal surface and the inner circumferential end of the seal surface extends from the second circumferential groove. A second radial groove is formed, and the seal case and the stationary-side seal ring are supplied with water in the first circumferential groove and the second circumferential groove.
Wherein the water supply hole and the second water supply hole are perforated.