JP2020143630A - Seal ring - Google Patents

Abstract

To provide a seal ring capable of improving mountability.SOLUTION: A seal ring 31 comprises: an annular mounting part 131 mounted on the inner peripheral surface of a stuffing box 50; and an annular lip part 133 that extends diagonally toward a shaft sleeve 4 side from one end side to the other end side of the mounting part 131, and slides on the outer peripheral surface of the shaft sleeve 4 at the tip on an inner peripheral side. On the outer peripheral surface of the other end side end part of the mounting part 131, an annular protrusion 140 is formed into a wedge shape, and in the mounting part 131, a core metal 120 is embedded only in a portion other than a portion where the annular protrusion 140 is formed.SELECTED DRAWING: Figure 4

Description

The present invention relates to a seal ring, and more particularly to a structure of a fitting portion of the seal ring.

For example, the pump described in Patent Document 1 has a shaft seal portion in which a plurality of seal rings (oil seals) are fitted on the inner peripheral surface of the stuffing box. This type of seal ring is interposed between the stuffing box, which is a fixing member, and the rotating shaft of the pump, which is a rotating member, to seal the annular gap between the two members.

Japanese Unexamined Patent Publication No. 2003-222246

Here, in some shaft seals of this type, the seal ring is tightened with respect to the inner peripheral surface of the stuffing box. In this case, when the seal ring is attached to the stuffing box, the push sesame is brought into contact with the side surface of the seal ring, and the push sesame is hit with a hammer to attach the seal ring. Therefore, there is room for improvement in improving wearability.
Therefore, the present invention has been made by paying attention to such a problem, and an object of the present invention is to provide a seal ring capable of improving wearability.

In order to solve the first problem, the seal ring according to one aspect of the present invention is a seal ring interposed between an outer fixing member and an inner rotating member to seal an annular gap between the two members. The annular mounting portion mounted on the inner peripheral surface of the fixing member and the annular mounting portion extending diagonally from one end side to the other end side of the mounting portion toward the rotating member side and on the inner peripheral side. An annular lip portion that slides into contact with the outer peripheral surface of the rotating member at the tip is provided, and the outer peripheral surface of the other end portion of the mounting portion is formed in a wedge shape that expands in diameter toward the one end side. An annular protrusion is provided, and a core metal is embedded in the mounting portion only in a portion other than the portion where the annular protrusion is formed.

According to the seal ring according to one aspect of the present invention, a wedge-shaped annular protrusion is provided on the outer periphery of the other end of the mounting portion, and the sealing ring is limited to a portion other than the portion where the annular protrusion is formed. Since the length of the core metal in the mounting part was shortened and embedded so that it could be positioned in the same position, the wedge-shaped annular protrusion was easily elastically deformed inward in the radial direction when pushed in the axial direction during mounting. It is possible.
As a result, when the seal ring is attached to a fixing member such as a housing, the seal ring can be easily attached to the desired attachment position in the fixing member by pushing the seal ring by hand in the axial direction without hitting it with a hammer. Then, after mounting, when an internal pressure is applied to the sealed ring in the mounted state, the wedge-shaped annular protrusion is pushed into the inner peripheral surface of the fixing member to generate a drag force against the pulling direction, and the mounting position is reliably held. Therefore, according to the seal ring according to one aspect of the present invention, the wearability can be improved.

As described above, according to the present invention, wearability can be improved.

It is a schematic vertical sectional view explaining one Embodiment of the pump provided with the seal ring which concerns on one aspect of this invention in the shaft sealing part. It is an enlarged view of the shaft seal part of FIG. It is a figure explaining one Embodiment of the seal ring which concerns on one aspect of this invention, FIG. (A) is the perspective view seen from the front upper left side which shows by breaking a part, (b) is part breaking. The perspective view seen from the upper right of the back surface, (c) is a front view. It is a figure explaining one Embodiment of the seal ring which concerns on one aspect of this invention, and the figure shows a part of the cross section along the axis in an enlarged view. It is a figure explaining an example of the conventional seal ring, and in this figure, the cross section along the axis is enlarged and shown.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. The present embodiment is an example in which the seal ring according to one aspect of the present invention is applied to a shaft seal portion in a pump used for pumping a slurry.
The drawings are schematic. Therefore, it should be noted that the relationship, ratio, etc. between the thickness and the plane dimension are different from the actual ones, and the drawings include parts in which the relationship and ratio of the dimensions are different from each other.
In addition, the embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention describes the material, shape, structure, and arrangement of components. Etc. are not specified in the following embodiments.

As shown in FIG. 1, the pump 100 of the present embodiment includes a casing 1, an impeller 2 supported at the tip of a shaft 3 projecting into the casing 1, and an expeller 5 provided behind the impeller 2. A seal ring type shaft sealing portion 10 provided behind the expeller 5 is provided. In the example of the present embodiment, the shaft 3 has a hollow cylindrical shaft sleeve 4 coaxially fitted on the outer peripheral surface of the portion of the shaft sealing portion 10 so as to rotate integrally.

As shown in an enlarged view in FIG. 2, the shaft sealing portion 10 has a stuffing box 50 which is a fixing member. Inside the stuffing box 50, a multi-stage seal structure 30 is provided in which a plurality of (three in this example) seal rings 31, 32, 33 according to the present embodiment are arranged in multiple stages in the axial direction.
Then, the sealing rings 31, 32, 33 of the multi-stage sealing structure 30 are mounted on the inner peripheral surface of the stuffing box 50 by forming a concave annular tubular step portion along the axial direction. A seal mounting portion 51 is provided.

The seal rings 31, 32, 33 constituting the multi-stage seal structure 30 are sequentially attached to the seal attachment portions 51 formed in the stuffing box 50 along the axial direction. A disk-shaped seal cover 57 is attached to the trailing edge of the seal mounting portion 51 on the atmosphere side, and an appropriate position of the seal cover 57 is fixed to the rear end surface of the stuffing box 50 by a fixing bolt 58.
In the present embodiment, the stuffing box 50 is formed with an annular convex portion 51a projecting inward in the radial direction at the front edge portion on the wetted side of the seal mounting portion 51. The trailing edge of the seal mounting portion 51 on the atmosphere side is used as the insertion port for the seal rings 31, 32, 33, and the annular convex portion 51a of the front edge portion on the liquid contact side of the seal mounting portion 51 is a shaft. It is a stopper that determines the position of the seal ring 31 in front of the direction.

As described above, the shaft sealing portion 10 of the present embodiment has a multi-stage sealing structure 30 composed of a plurality of sealing rings 31, 32, 33, whereby the sealing rings 31, 32, 33 are formed in the outer stuffing box. It is interposed between the 50 and the inner shaft sleeve 4 so that the annular gap between the two members can be reliably sealed in multiple stages.
Here, since the seal rings 31, 32, 33 of the present embodiment have the same shape, the configuration of the first seal ring 31 will be described in detail below, and the configurations of the second and third seal rings 32, 33 will be described below. Omit.

As shown in FIG. 3, the first seal ring 31 includes a rubber portion 130 formed in a substantially annular shape from an elastomer such as rubber and having flexibility, and a core metal 120 embedded inside the rubber portion 130. Has. As the material of the rubber portion 130, for example, nitrile rubber, fluorine-based rubber, or the like can be used. Further, as the material of the core metal 120, for example, an iron material or the like can be used.
As shown in the enlarged view of FIG. 4, the rubber portion 130 includes an annular mounting portion 131 and an annular lip portion 133. The mounting portion 131 is a portion mounted on the inner peripheral surface of the seal mounting portion 51 formed on the stuffing box 50.

The lip portion 133 extends diagonally from one end side to the other end side of the mounting portion 131 toward the shaft sleeve 4 side at the time of mounting, and slides on the outer peripheral surface of the shaft sleeve 4 at the inner peripheral side tip surface 138. It is attached so that it touches.
On the other end side (the side of the front side surface 134) of the mounting portion 131, an annular protrusion 140 having a wedge-shaped outer peripheral surface 135 whose diameter increases toward one end side is provided. The core metal 120 is embedded in the mounting portion 131 only in a portion other than the portion where the annular protrusion 140 is formed.

The core metal 120 of the present embodiment is a metal plate member having an L-shaped cross-sectional shape on the meridional surface, and one side of the L-shape is embedded along the axial direction of the seal ring 31. The ring portion 121 is formed, and the other side forming an L shape is a disk surface portion 123 embedded along the radial direction of the seal ring 31. The embedding position of the lower end portion of the disk surface portion 123 is fixed near the base end portion of the lip portion 133.
The portion where the annular portion 121 and the disk surface portion 123 are continuous is bent so that the surface of the annular portion 121 and the surface of the disk surface portion 123 are orthogonal to each other to form the bent R portion 122. .. The embedding position of the front end surface 124 of the annular portion 121 is set to a position axially rearward of the position of the rearmost end portion of the annular projection 140.

The outer peripheral surface 135 of the annular projection 140 is inclined in a tapered shape that increases in diameter from the front to the rear. The inclination angle θ of the outer peripheral surface 135 of the annular protrusion 140 with respect to the horizontal axis HL is adjusted according to the hardness of the first seal ring 31 (for example, when the hardness is large, the inclination angle θ is small, and when the hardness is small, the inclination angle θ is small. The angle θ is increased). The inclination angle θ is preferably in the range of, for example, 5 to 30 degrees in the present application.

Next, the steps of assembling the seal rings 31, 32, 33 to the shaft sealing portion 10 will be described.
When mounting the seal rings 31, 32, 33 on the seal mounting portion 51 of the stuffing box 50, first, as shown in FIG. 2, the assembling worker is at the rear of the stuffing box 50. From the opening 50 g, the first seal ring 31 is manually pushed into the seal mounting portion 51 toward the side surface of the annular convex portion 51a on the front side of the seal mounting portion 51 and inserted.

Next, the assembling worker abuts the rear side surface 139 (see FIG. 4) of the first seal ring 31 with the front side surface 134 (see FIG. 4) of the second seal ring 32 from the rear side to attach the seal. The second seal ring 32 is pushed together with the first seal ring 31 toward the front in the axial direction so as to be along the inner surface of the portion 51.
Here, according to the seal rings 31 and 32 of the present embodiment, a wedge-shaped annular protrusion 140 is provided on the outer periphery of the other end side of the mounting portion 131, and the annular protrusion 140 is further formed. Since the length of the core metal 120 in the mounting portion 131 is shortened and embedded so that it is located only in the portion other than the portion other than the portion, the wedge-shaped annular protrusion 140 is pushed in the axial direction during mounting. , It can be easily elastically deformed inward in the radial direction.

As a result, the mounting portion 131 can be easily fitted into the seal mounting portion 51. Hereinafter, in the same manner, the third seal ring 33 can be easily inserted into the rear side surface 139 of the seal ring 32 from the rear side.
As described above, according to the seal rings 31, 32, 33 of the present embodiment, the annular mounting portion 131 has a tapered shape in which the outer peripheral surface 135 of the annular projection 140 expands in diameter from the front to the rear. Since it is inclined, the work of mounting the stuffing box 50 on the seal mounting portion 51 becomes extremely easy.

Next, the action and effect of the multi-stage seal structure 30 using the seal rings 31, 32, 33 will be described.
Here, an example of a conventional seal ring will be described with reference to FIG.
As shown in the figure, the conventional seal ring 200 has a rubber portion 300 and a core metal 210 embedded inside the rubber portion 300. The rubber portion 300 is an annular mounting portion 301 mounted on the inner peripheral surface of the seal mounting portion such as the stuffing box 50, and the rubber portion 300 is directed from one end side to the other end side of the mounting portion 301 toward the shaft sleeve 4 side. It is provided with an annular lip portion 303 that extends obliquely and is in sliding contact with the outer peripheral surface of the shaft sleeve 4 at the tip 308 on the inner peripheral side. The outer peripheral surface 307 of the mounting portion 301 is a cylindrical surface formed along the horizontal axis HL, and chamfered portions 305 and 306 are formed at the front end and the rear end of the outer peripheral surface 307, respectively.

Here, the outer peripheral surface 307 of the mounting portion 301 is tightened with respect to the inner peripheral surface of the seal mounting portion of the stuffing box, and when the seal ring 200 is mounted on the stuffing box, the seal ring 200 is used. The push sesame is brought into contact with the side surface, and the push sesame is hit with a hammer to attach the seal ring 200.
The core metal 210 is a metal plate member having an L-shaped meridional cross-sectional shape, and one side of the L-shaped metal ring portion is embedded along the axial direction of the seal ring 200. 201, and the other side forming an L shape is a disk surface portion 203 embedded along the radial direction of the seal ring 200. The embedding position of the lower end portion of the disk surface portion 203 extends along the rear end surface 309 of the seal ring 200 to the inside of the connecting portion 302 connecting the lip portion 303 and the mounting portion 301.

The portion where the annular portion 201 and the disk surface portion 203 are continuous is bent so that the surface of the annular portion 201 and the surface of the disk surface portion 203 are orthogonal to each other to form the bent R portion 202. .. The embedding position of the front end surface 204 of the annulus portion 201 extends to the vicinity of the front end portion 304 of the mounting portion 301 (a position that overlaps the formation position of the chamfered portion 305 in the axial direction).
In contrast to the conventional seal ring 200, in the multi-stage seal structure 30 of the present embodiment, as described above, the seal rings 31, 32, 33 are wedge-shaped on the outer periphery of the other end of the mounting portion 131. The length of the core metal 120 is shortened so that the core metal 120 in the mounting portion 131 is located only in the portion other than the portion where the annular protrusion 140 is formed. It is embedded in the mounting portion 131.

Therefore, the annular protrusion 140 having the wedge-shaped outer peripheral surface 135 is radially inward when the stuffing box 50 is mounted on the seal mounting portion 51 and is pushed inward from the rear opening 50 g of the stuffing box 50. It can be easily elastically deformed inward.
As a result, according to the seal rings 31, 32, 33 according to the present embodiment, when the seal ring is attached to a fixing member such as the stuffing box 50, the seal ring 200 illustrated in FIG. 5 can be hit with a hammer. The seal rings 31, 32, and 33 can be easily mounted at the desired mounting position in the fixing member simply by pushing the seal rings 31, 32, and 33 with a relatively weak force in the axial direction without applying a strong force.

Then, after the seal rings 31, 32, 33 are attached, when internal pressure is applied to the seal rings 31, 32, 33 in the attached state, the annular protrusion 140 having the wedge-shaped outer peripheral surface 135 is formed on the stuffing box 50. The inner peripheral surface of the seal mounting portion 51 is recessed, and a drag force is generated against the pulling direction to reliably hold the mounting position. Therefore, according to the seal rings 31, 32, 33 according to the present embodiment, the wearability can be improved.

It should be noted that the seal ring according to the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

1 Casing 2 Impeller 3 Shaft (Rotating shaft)
4 Shaft sleeve 5 Expeller 6 Washer 7 Shaft support 7a, 7b Bearing 8 Housing 10 Shaft seal 20 Lantern ring 30 Multi-stage seal structure 31 First seal ring (seal ring)
32 Second seal ring (seal ring)
33 Third seal ring (seal ring)
50 Stuffing box 51 Seal mounting part 57 Seal cover 58 Fixing bolt 100 Pump (fluid equipment)
120 Core metal 121 Ring part 122 Bending R part 123 Disk surface part 124 Front end surface 130 Rubber part 131 Mounting part 133 Lip part 134 Front side side 135 Outer surface 138 Inner peripheral side tip surface 139 Rear side 140 Circular protrusion

Claims (2)

A seal ring that is interposed between the outer fixing member and the inner rotating member to seal the annular gap between the two members.
An annular mounting portion mounted on the inner peripheral surface of the fixing member and an annular mounting portion that extends diagonally from one end side to the other end side of the mounting portion toward the rotating member side and rotates at the tip on the inner peripheral side. An annular lip portion that slides into the outer peripheral surface of the member is provided.
An annular protrusion formed in a wedge shape whose diameter increases toward the one end side is provided on the outer peripheral surface of the other end portion of the mounting portion, and the annular protrusion is formed in the mounting portion. A seal ring characterized in that the core metal is embedded only in the part other than the wedge part. A pump comprising the seal ring according to claim 1 in a shaft sealing portion.

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