JPS62292972A - Shaft seal device - Google Patents

Abstract

PURPOSE:To prevent the breakage of a seal ring by accommodating the seal ring into a ductile member and installing said seal ring onto a seal case. CONSTITUTION:The shaft seal device consists of a seal casing 16 surrounding the outer periphery of a flange 11, seal case 7 which is positioned inside the seal casing 16 and used for accommodating a seal ring 10, and a coil spring 9 for pressing the seal case 7. The seal ring 10 is accommodated into a ductile member 13 (e.g., bronze) and installed onto the seal case 7. Therefore, even if an impact force due to the vibration and variation of hydraulic pressure during operation acts onto the seal ring 10, the breakage of the seal ring 10 is prevented, since the seal ring 10 is protected by the ductile member 13.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [4 Field of Industrial Application] The present invention relates to a shaft sealing device for preventing fluid leakage from the main shaft of a water turbine, pump, etc. This invention relates to a shaft sealing device that seals by sliding a seal ring around the shaft.

[Conventional technology]

In general, in hydraulic machines such as water turbines and pumps, as shown in FIG. A sealing device 2 is installed at the rC to prevent leakage of high-pressure turbid water on the side. In the figure, 4 is a guide vane installed to adjust the flow rate, and 5 is a draft pipe serving as a flow channel.

There are various structures of shaft sealing devices, but for hydraulic machines, there are Japanese Utility Model Application Publication No. 58-12678 and Japanese Patent Application Laid-open No. 59-936.
No. 7 proposes an end face type shaft sealing device. FIG. 6 is a diagram showing an implementation row of the shaft sealing device disclosed in Japanese Patent Application Laid-Open No. 59-9367.

The shaft sealing device i is located inside a seal casing 16 that surrounds the outer periphery of the flange 11, and a seal case 7 that stores the seal ring 10, and the seal case 7.
It consists of an O-ring 8 provided on the surface facing the cover 12 and a coil spring 9 that presses the seal case 7.

In this shaft sealing device, the seal ring 10 pressed against the surface of the flange 11 and the O-ring 80 portion attached to the seal case 7 seal high pressure fluid on the impeller side.

Generally, ceramics or the like is used for the seal ring IO in consideration of wear resistance and water lubrication performance. Also,
For the flange 11, a hard metal with excellent wear resistance is conveniently used. In such a large shaft seal structure, as shown in FIG. 6, the seal ring 10 is fixed so as to protrude from the surface of the seal case in consideration of wear during transmission.

Since the seal ring 10 is fragile, it may break due to vibration during operation or impact force due to fluctuations in water pressure, resulting in abnormal water leakage.For this reason, from the viewpoint of mechanical strength, it is recommended to use a non-breakable resin in the seal ring 10. However, since the earth and sand abrasion resistance is low, the seal ring 10 wears out early, and operation becomes impossible in a short period of time.

Therefore, for such a shaft seal device, damage to the seal ring 10 can be prevented from the viewpoint of reliability.

What is needed is something with a simple structure that can provide stable water sealing performance over a long period of time. [Problem that the invention attempts to solve] In the conventional example above, vibrations during operation can damage the seal ring and cause abnormal water leakage. Therefore, there was a problem that stable water sealing performance could not be obtained for a long period of time.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks, and it is an object of the present invention to provide a shaft sealing device with a simple structure that can prevent damage to the seal ring.

[Means for solving problems]

The above objects are achieved by retracting and securing the sealing ring to the slidable ductile member and by keeping the sealing ring visible.

[Effect]

The ductile member housing and securing the seal ring operates to protect the seal ring.

Thereby, the sealing ring is reinforced and contained so that it cannot be damaged.

〔Example〕

The details of the present invention will be explained below using Mega.

FIG. 1 shows an embodiment of a shaft sealing device according to the present invention. In Figure $1, the same parts as in Figure 6 are given the same symbols. The shaft seal structure is almost the same as that shown in FIG. 6, but the difference is that the seal ring 10 is housed in a ductile member 13 (for example, made of bronze) and attached to the seal case 7.

Even if an impact force due to vibration or water pressure fluctuation during operation of this shaft seal device acts on the seal ring 10, the seal ring 10 is protected by the ductile member 13, so damage to the seal ring 10 is prevented.

Further, the width of the ductile member 13 is narrower near the sliding surface than at the attachment portion of the seal case 7. Therefore, the rigidity in the radial view is lower than when the width near the sliding part of the ductile member 13 is the same as the mounting part of the seal case 7, and the conformability of the sole ring 10 is improved, resulting in stability. It provides excellent water sealing performance. Furthermore, since heat dissipation is improved, the sliding surface temperature can be lowered and stable water film formation can be expected.

Even if the seal ring 10 is worn and the ductile member 13 comes into contact with the surface of the flange 11, the ductile member 13 exhibits a low coefficient of friction, so stable sliding characteristics can be obtained.

On the other hand, since the ductile member 13 that stores and fixes the seal ring 10 can be easily attached to and detached from the seal case 7, handling is improved compared to the conventional example in which the seal ring 10 is directly attached to the seal case 7, and the seal ring 10 can be easily replaced. It becomes easier to do.

FIG. 2 shows an embodiment in which the ductile member 13a is brought into contact with the sliding surface of the flange 11 from the beginning.

Even in this case, the same effect can be obtained. Furthermore, in this structure, since the seal ring 10 is housed and fixed so as to be included in the concave ductile member 13a, the seal ring 1
Since the protruding portion of the sole ring 10 is eliminated, the sole ring 10 becomes easier to handle, and thus workability is improved.

Furthermore, since the amount of ductile member 13a is small, material costs can be saved.

FIG. 3 shows an embodiment in which a new ceramic seat ring 15 is installed on the surface of the flange 11 with the aim of improving wear resistance. The seat ring 15 is housed and fixed in the case 14a. Therefore, since the seat ring 15 is protected by the case 14aK, it will not be damaged by centrifugal force or the like during one rotation. Further, the width of the ceramic seat ring 15 is set to be wider than the normal member 13a for storing and fixing the seal ring 10 in consideration of shaft misalignment during rotation. Ceramics are several times harder than flange materials and have thermal conductivity equivalent to metals. Therefore, the wear resistance on the flange side is improved and a long life can be expected.

The ceramic seat ring 15 may be integral. Further, it goes without saying that a sheet ring 15tj:, which has a ceramic coating formed on its J surface, will have the same effect.

FIG. 4 shows an embodiment in which two rows of flexible members (for example, braided gland packing) are attached to the seal ring 17. Since the flexible member is easily deformed by the weight of the seal case 7 or the sealing water pressure, is it acceptable? Although it was not possible to apply the seal ring 17 with the ductile member alone, since the seal ring 17 is protected by the ductile member 13b, the amount of deformation of the seal ring 17 can be maintained appropriately, and the seal surface pressure can be maintained at a predetermined level. It can be set to any value and stable water sealing performance can be obtained.

Furthermore, since the flexible member can be brought into close contact with the flange surface from the initial stage of assembly, more stable water-sealing performance can be expected than when ceramics or the like is used as the seal ring 17. Although the previous embodiments have used bronze as the ductile member, the same effect can be obtained even if cloth-filled resin is used as the smokable member.

〔Effect of the invention〕

According to the present invention, since the seal ring is housed and fixed in the ductile member, the ductile portion O protects the seal ring and can prevent damage to the seal ring.

Therefore, it has the effect of eliminating abnormal water leakage and exhibiting stable water sealing performance for a long period of time.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a shaft sealing device according to an embodiment of the present invention;
4 to 4 are longitudinal cross-sectional views showing other embodiments of the present invention, FIG. 5 is an f& cross-sectional view of a similar conventional water turbine, and FIG. 6 is a vertical cross-sectional view showing a conventional circumferential shaft sealing device. be.

Claims (1)

[Claims] 1. The rotary shaft has a flange, a seal case is provided in a casing surrounding the rotary shaft, and a seal ring is attached to the seal case, and the seal ring is pressed against the flange surface for sealing. 1. An end face type shaft sealing device, wherein the seal ring is housed in a ductile member and attached to a seal case. 2. The shaft sealing device according to claim 1, wherein bronze is used as the ductile member. 3. The shaft sealing device according to claim 1, wherein a cloth-filled resin is used as the ductile member. 4. The shaft sealing device according to claim 1, characterized in that ceramics are attached to the flange surface that contacts the seal ring.