JPH0618766U - Shaft seal device - Google Patents

Abstract

(57) [Abstract] [Purpose] Improving the sealing performance, miniaturization, easy assembly / disassembly, and long life of the shaft sealing device applied to the rotary shaft penetration part of turbomachines such as turbines and pumps. [Structure] The seal ring (30) on the rotating side and the seal ring (31) on the stationary side are pressed against each other in the axial direction to form a seal surface S. The seal rings (30) and (31) are composed of a plurality of arc plate-shaped divided pieces, and a reference ring (34) divided into two is provided on at least one rear surface in the circumferential direction so that the divided portions do not overlap. The reference rings (34) are displaced from each other, and the back surface of the reference ring (34) is supported by an elastic body (32).

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a shaft sealing device applied to a rotary shaft penetrating portion of a turbomachine such as a water turbine or a pump.

[0002]

[Prior art]

 The shaft seal device is installed for the purpose of sealing the fluid at the shaft penetration part of turbomachines such as water turbines and pumps. As such a shaft sealing device, a rotary side sealing member provided integrally with the rotating shaft and a stationary structure between the outer peripheral surface of the rotating shaft and a stationary structure into which the rotating shaft is inserted, and a stationary structure. There is often used a structure in which a stationary side seal member integrally provided on the above is brought into pressure contact with the pressure contact surface as a sealing surface.

FIG. 6 shows an example of a conventional shaft sealing device having such a configuration. That is, the sleeve (2) is integrally rotatably fitted on the outer peripheral surface of the rotating shaft (1), and the sleeve (2) serves as a rotating side seal member. A cylindrical seal box (4) is fixed to a casing (3), which is a stationary structure through which the rotary shaft (1) is inserted, and a plurality of gland packings are provided on the inner peripheral portion of the seal box (4). (5) is fitted and inserted, and this gland packing (5) serves as a stationary side seal member. The outer peripheral surface of the sleeve (2) and the inner peripheral surface of the gland packing (5) are in pressure contact with each other, and this pressure contact surface serves as a sealing surface S to prevent the pressure fluid (6) from flowing out.

The seal box (4) is provided with a packing retainer (7), and by tightening this with a bolt (8), a required sealing surface pressure is applied to the sealing surface S. In addition, an intermediate ring (9) is inserted in the middle of the plurality of gland packings (5) to form a constant space (10), and a pipe (12) is supplied from the fresh water supplier (11) to this space (10). Fresh water is supplied via this to prevent heat generation and insufficient lubrication of the sealing surface S due to tightening of the gland packing (5). Note that (13) and (14) are piping and auxiliary equipment for collecting the leaked fluid.

[0005]

[Problems to be solved by the device]

 However, in the above-described conventional shaft sealing device, the fresh water supply device (11) provided for cooling and lubrication of the gland packing (5), the pipe (13) for collecting the leaked fluid and the auxiliary device (14), etc. Since the structure is complicated and large, the entire shaft sealing device is large. In addition, if the gland packing (5) leaks more than the specified amount, adjustment management such as tightening the bolt (8) and pushing the packing retainer (7) is always required. It was troublesome. Furthermore, since the gland packing (5) has a multi-stage structure and is tightened on the outer peripheral surface of the sleeve (2), seizure may occur due to insufficient lubrication, and there is a problem that the life of the shaft sealing device is relatively short due to damage and abrasion. there were.

The present invention has been made to solve such a problem, and by improving the sealing property, the fresh water supply device, the leak water recovery device, etc. can be downsized, and the configuration can be made compact and the operation management can be performed. It is an object of the present invention to provide a shaft sealing device that is easy to assemble, disassemble, etc., has good maintainability, and has a long life.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention axially presses a rotating side seal ring attached to a rotating shaft penetrating a fixed casing onto a stationary side seal ring attached to the fixed casing, and presses the contact surface. A sealing surface, wherein at least one of the rotary side seal ring and the stationary side seal ring is composed of a plurality of arc plate-shaped divided pieces divided in the circumferential direction. , A split reference ring is provided on the back side of the split seal ring, and the split portion of the reference ring and the split portion of the seal ring are shifted in the circumferential direction so that they do not overlap in the axial direction. Thus, the present invention proposes a shaft seal device characterized by fastening and fixing the reference ring and the seal ring, and further supporting the back surface of the reference ring with an elastic body.

[0008]

[Action]

 According to the present invention, the sealing surface, which is the pressure contact surface between the stationary side seal ring and the rotating side seal ring, is a surface that is orthogonal to the axial direction on the outer peripheral side of the rotating shaft. The resistance against the axial movement of the pressurized fluid is large, and the sealing performance is improved compared to the conventional structure in which the sealing surface is along the axial direction.

Further, each seal ring is composed of a plurality of arcuate plate-shaped divided pieces that are divided in the circumferential direction, and the reference ring for two-divided flow arranged on the back surface of the seal ring is arranged so that the divided surfaces do not overlap. Since the seal ring is fixed by shifting in the direction, the flatness of the seal ring divided into two or more becomes accurate with the reference ring divided into two serving as a reference surface. Therefore, the gap between the sealing surfaces that are pressed against each other is always small, and the amount of water leaking from the gap is small, so that not only can the auxiliary equipment for fresh water supply and leak recovery be made compact, but operation management can be facilitated.

Moreover, since each seal ring is made up of arcuate plate-shaped divided pieces that are divided in the circumferential direction, the assembly and disassembly work can be performed relatively easily, and maintainability is improved, resulting in long life. Life can be extended.

[0011]

【Example】

 FIG. 1 is a vertical side view showing an embodiment of the present invention, and FIG. 2 is a II-II horizontal sectional view of FIG.

In the shaft sealing device of the present embodiment, the rotary shaft (21) penetrates the casing (22) on the stationary side, and the disk-shaped rotary ring housing is provided in the vicinity of the casing penetrating portion of the rotary shaft (21). (23) is fitted coaxially. The rotating ring housing (23) is integrally and rotatably fixed to the rotating shaft (21) by a screw sleeve (24) screwed to the rotating shaft (21). The rotating ring housing (23) is composed of a pair of approximately semicircular housing elements (23a) which are detachably coupled to each other by a fastener (25) such as a bolt.

On the other hand, a disk-shaped stationary ring housing (26) is axially slidably fitted to the casing (22) so as to face the rotating ring housing (23) in the axial direction. There is. The stationary ring housing (26) is sealed by an O-ring (27) at a portion to be fitted and inserted into the casing (22), and the rotating ring housing (23) is provided by an elastic member (28) such as a compression coil spring. Biased to the side. Similar to the rotating ring housing (23), the stationary ring housing (26) is also constructed by detachably coupling a pair of substantially semicircular housing elements with a fastening tool (29) such as a bolt. ing.

On the lower surface of the stationary ring housing (26), a stationary seal ring (31), which is divided into two in the circumferential direction, is attached as a stationary seal member by a holding plate (35). Further, the rotating ring housing (23) is provided with a rotating side seal ring (30) which is divided into two in the circumferential direction at the dividing surface A as a rotating side sealing member, and the rear surface (the lower surface in FIG. 1) of the divided surface A reference ring (34) divided in two in the circumferential direction at B is arranged. The rotating side seal ring (30) and the reference ring (34) are circumferentially displaced so that the respective dividing surfaces A and B do not overlap in the axial direction, and are fastened and fixed to each other by bolts (36). Is pressed from the bottom side of the rotary ring housing (23) toward the stationary side seal ring (31) by an elastic body (32) made of, for example, a rubber ring, and the upper end surface is held by the holding plate (33). Has been done. The end faces of these seal rings (30) and (31) perpendicular to the axial direction face each other outside the rotary shaft (21), and the facing faces are pressed against each other as a sealing face S.

A seal (37) attached to the casing (22) is in contact with the outer peripheral surface of the rotary ring housing (23), and is supplied from the fresh water feeder (11) through a pipe (12). There is an isolation between the lubrication water (38) and the pressure fluid (6) which are to be used. The fluid leaked to the upper atmosphere side is recovered by the recovery auxiliary machine (14) through the pipe (13).

FIG. 3 is a view showing a deformed state of the rotary seal ring (30). If the split reference ring (34) of this embodiment is not provided, the split surface A is generally deformed so as to open as shown by the dotted line in FIG. However, as in the present embodiment, if the split reference ring (34) is provided on the back surface of the rotary seal ring (30) and the split surfaces A and B are circumferentially displaced so as not to overlap each other, the structure shown in FIG. The deformation as in a) does not occur, and as shown in FIG. 3B, the flatness of the rotary seal ring (30) is accurately maintained. The relative seal face clearance h shown in FIG. 3A is generally about several tens of μm, and the deformation amount δ shown by the broken line when the reference ring (34) is not present also depends on the diameter of the rotary seal ring (30). When the diameter is large, it becomes several hundred μm. The leakage amount is large as shown by the curve C in FIG. 4 when the reference ring (34) is not provided, but is small as shown by the curve D in this embodiment.

FIG. 5 is a horizontal sectional view similar to FIG. 2, showing a rotary ring housing (23) taken out of another embodiment of the present invention. In this embodiment, the rotary seal ring (30 ') is circumferentially divided into six parts on the dividing surface A', and the reference ring (34) on the back surface is the dividing surface indicated by the broken line B in the drawing in the circumferential direction. It is divided into two. In this case as well, the above-mentioned deformation does not occur in the split rotary seal ring (30 '), and the flatness is accurately maintained.

In the above embodiment, the split reference ring (34) is applied to the rotary seal rings (30), (30 ') side, but it may be applied to the stationary side or both sides. Further, in the above embodiment, both the rotary seal rings (30) and (30 ') and the stationary seal ring (31) are divided into a plurality of pieces, but either one may be an integral type ring which is not divided. In that case, the casing (22) on the upper side of FIG. 1 can be inserted in the axial direction by forming it into an opening type using a flange or the like.

[0019]

EFFECTS OF THE INVENTION The shaft sealing device according to the present invention is configured as described above, and since there is no deformation of the seal ring at the portion where the rotating main shaft penetrates the stationary side casing, the sealing performance is good and the pressure fluid There is little leakage. Therefore, a large-sized fresh water supply auxiliary device or a leakage fluid recovery auxiliary device is not required, and the shaft sealing device can be made compact. Further, since the end surface of the seal ring is axially aligned and pressed against by a spring or the like to form a sealing surface, adjustment is unnecessary and operation management is easy. Furthermore, since it is a split type, it can be integrated at required parts, assembly and disassembly is easy, and maintainability is greatly improved. In addition, the pressure contact length of the sealing surfaces facing each other is short, and the lubrication by the pressure fluid is sufficient to prevent seizure of sliding parts and other damages, thus prolonging the life of the shaft sealing device and requiring less frequent replacement.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a shaft sealing device according to an embodiment of the present invention.

FIG. 2 is a horizontal sectional view taken along the line II-II of FIG.

FIG. 3 is a diagram for explaining the operation of the above embodiment.

FIG. 4 is a diagram for explaining the effect of the above embodiment.

FIG. 5 is a horizontal sectional view showing a rotary ring housing according to another embodiment of the present invention.

FIG. 6 is a vertical cross-sectional side view showing an example of a conventional shaft sealing device.

[Explanation of symbols] (1) Rotating shaft (2) Sleeve (3) Casing (4) Seal box (5) Gland packing (6) Pressure fluid (7) Packing retainer (9) Intermediate ring (11) Fresh water feeder ( 14) Auxiliary equipment (21) Rotating shaft (22) Casing (23) Rotating ring housing (26) Stationary ring housing (28) Elastic members (30), (30 ') Rotating side seal ring (31) Stationary side seal ring ( 32) Elastic body (33) Holding plate (34) Two-divided reference ring (37) Seal (38) Lubricating water A, A ', B Divided surface S Sealed surface

Claims (1)

[Scope of utility model registration request] 1. A shaft sealing device in which a rotary side seal ring mounted on a rotary shaft passing through a fixed casing is axially pressed against a stationary side seal ring mounted on the fixed casing, and the pressure contact surface serves as a sealing surface. At least one of the rotary side seal ring and the stationary side seal ring is constituted by a plurality of arc plate-shaped divided pieces divided in the circumferential direction, and the divided seal ring is formed. A reference ring divided into two is placed on the back of the
The divided portion of the reference ring and the divided portion of the seal ring are shifted in the circumferential direction so as not to overlap in the axial direction, the reference ring and the seal ring are fastened and fixed, and the rear surface of the reference ring is made of an elastic body. A shaft sealing device characterized by being supported by.