CN112431789A

CN112431789A - Sealing ring with high-efficient sealing performance

Info

Publication number: CN112431789A
Application number: CN202011333860.9A
Authority: CN
Inventors: 董志强; 刁成杰; 潘再兵
Original assignee: KSB Shanghai Pump Co Ltd
Current assignee: KSB Shanghai Pump Co Ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2021-03-02

Abstract

The present invention provides a seal ring for a pump, the seal ring being mountable on an impeller, one end face of the seal ring being provided with one or more groove regions for pumping liquid to the outside of the seal ring, and/or a seal dam region for raising the pressure of the liquid to inhibit leakage flow. The outer contour of the groove area drives the liquid to rotate together when rotating, so that the liquid is pumped to the outside of the sealing ring and/or sucked into the liquid. The groove area is used for enabling liquid in the groove area to flow around the inner wall of the groove area, and the inner wall of the groove area is used for enabling the liquid to flow to the sealing dam area so as to block the circulation of leakage flow and/or increase the rigidity of a liquid film in the sealing gap.

Description

Sealing ring with high-efficient sealing performance

Technical Field

The invention relates to the field of mechanical engineering, in particular to a sealing ring with high-efficiency sealing performance.

Background

Fig. 1 shows a partial schematic cross-sectional view of a pump according to the prior art. As shown in fig. 1, the conventional pump 100 may include an impeller 1, a housing 2, an impeller seal ring 3, and a pump body seal ring 4, wherein the impeller seal ring 3 is mounted on the impeller 1 to rotate together with the impeller 1, belonging to a rotating part, and the pump body seal ring 4 is mounted on the housing 2, belonging to a stationary part. As shown in fig. 2B, the seal ring gap 20 between the impeller seal ring 3 and the pump body seal ring 4 communicates between the outlet region (B) and the inlet region (a) of the impeller 1. As can be seen from the enlarged partial view of fig. 2C, the sealing surface of the conventional impeller seal ring 3 is a flat surface.

As shown in the pressure distribution diagram of fig. 2A, the pressure in the gap between the impeller seal ring 3 and the pump body seal ring 4 is approximately linear with the radial distance of the gap (as shown in fig. 2A, the pressure curve is a steep slope). The pressure difference before and after the seal ring gap 20 (outlet side at B and inlet side at a as shown in fig. 2B, respectively) is equal to the pressure difference between the outlet side and the inlet side of the impeller 1. Referring to fig. 1 and 2A, when the pump 100 is in operation, a high pressure region is formed in the outlet region (B) of the impeller 1 by the pressurizing action of the impeller 1, as compared with the inlet region (a) of the impeller 1. In the direction shown in fig. 1, when the pump 100 is operated, a part of the liquid can flow from the outlet side to the inlet side by the gap 20 between the rotating part impeller 1 and the stationary part housing 2 under the pressure difference between the outlet side (B) and the inlet side (a) of the impeller 1, and a leakage flow is formed. The presence of leakage flow can cause volume losses and reduce unit efficiency, and leakage flow can also affect the outlet pressure of the impeller 1, resulting in a reduced lift.

As shown in fig. 1 and 2C, the present pump 100 generally employs a radial seal ring configuration. In order to reduce the amount of leakage at the gap 20 between the impeller seal ring 3 and the pump body seal ring 4, the gap between the impeller seal ring 3 and the pump body seal ring 4 is usually made relatively small (for example, about 0.5 to 1% of the diameter of the impeller 1). However, this makes it easy for accidents such as rubbing or seizure to occur between the radial seal ring 3 of the impeller 1 and the casing seal ring 4. Moreover, the smaller clearance values have higher requirement on the centering performance of the shaft system, and the installation difficulty is increased.

Disclosure of Invention

An object of the present invention is to provide a seal ring having high sealing performance.

According to an aspect of the present invention, there is provided a seal ring having one end face provided with one or more groove regions for pumping liquid to the outside of the seal ring, and/or a seal dam region for raising the pressure of the liquid to suppress leakage flow.

According to the seal ring of the above aspect of the invention, the outer profile of the groove region forces the liquid to rotate together when rotated, to pump the liquid out of the seal ring and/or to suck the liquid in.

According to the seal ring of the above aspect of the invention, the groove region is configured to allow the liquid in the groove region to flow around the inner wall of the groove region, and the inner wall of the groove region is configured to allow the liquid to flow toward the seal dam region to block the flow of the leakage flow and/or increase the rigidity of the liquid film in the seal gap.

According to the seal ring of the above aspect of the invention, the groove region comprises one or more unidirectional spiral grooves and/or one or more bidirectional spiral grooves, wherein the unidirectional spiral grooves have an airfoil shape capable of pumping liquid to the outside of the seal ring, and/or the bidirectional spiral grooves have an airfoil shape capable of pumping liquid to the outside of the seal ring, and/or the grooves are evenly distributed along the center of the seal ring.

According to the seal ring of the above aspect of the invention, the seal ring gap is adjusted by adding or removing a shim pack mounted between the bearing body and the bearing holder of the pump or by adjusting the thickness of the shim pack; and/or the sealing ring comprises a planar sealing ring, the end face is a sealing face, and the gasket group comprises one or more gaskets.

According to another aspect of the present invention there is provided a pump comprising a seal ring mounted on an impeller, one end face of the seal ring being provided with one or more groove regions for pumping liquid outwardly of the seal ring, and/or a seal dam region for raising the pressure of the liquid to inhibit leakage flow.

According to the pump of the above aspect of the invention, the outer profile of the groove region urges the liquid to rotate together when rotating with the impeller, so as to pump the liquid out of the sealing ring and/or suck the liquid in.

According to the pump of the above aspect of the invention, the groove region is adapted to cause the liquid in the groove region to flow around an inner wall of the groove region when rotating with the impeller, the inner wall of the groove region being adapted to cause the liquid to flow toward the seal dam region to impede the flow of the leakage flow and/or increase the stiffness of the liquid film in the seal gap.

According to the pump of the above aspect of the present invention, the groove region includes one or more unidirectional spiral grooves and/or one or more bidirectional spiral grooves, wherein the unidirectional spiral grooves have an airfoil shape capable of pumping liquid to the outside of the seal ring, and/or the bidirectional spiral grooves have an airfoil shape capable of pumping liquid to the outside of the seal ring, and/or the grooves are uniformly distributed along the center of the seal ring; and/or the sealing ring comprises a planar sealing ring, and the end face is a sealing face.

The pump according to the above aspect of the present invention further includes one or more of an impeller, a volute, a pump body seal ring, a bearing body, a bearing bracket, and a shim pack installed between the bearing body and the bearing bracket; and/or adjusting the seal ring gap by adding or removing the shim packs or adjusting the thickness of the shim packs, the shim packs including one or more shims.

As described above, according to the embodiments of the present invention, since the sealing ring having a pressurizing function and/or improving the liquid film rigidity of the liquid in the gap between the sealing rings is used, the present invention can effectively reduce the leakage amount and well balance the axial force of the pump set, thereby improving the operation stability. Furthermore, the seal ring clearance between the seal ring and the casing static seal ring is adjustable, so that a minimum seal clearance can be maintained to ensure optimum performance. The invention has simple structure and easy installation, can effectively avoid the collision and friction between the sealing ring and the static sealing ring of the shell, and can also prolong the service life of the sealing ring.

Drawings

FIG. 1 shows a schematic partial cross-sectional view of a pump according to the prior art;

FIGS. 2A to 2C are schematic pressure profiles of the relationship between pressure in the seal ring gap and radial distance of the gap, schematic partial cross-sectional views of the impeller seal ring and the pump body seal ring, and partial schematic views of the impeller seal ring, respectively, according to the prior art;

FIGS. 3A through 3C respectively show a schematic pressure profile of the pressure in the seal ring gap versus the radial distance of the gap, a schematic partial cross-sectional view of the impeller seal ring and the pump body seal ring, and a partial schematic view of the impeller seal ring, in accordance with one embodiment of the present invention;

FIGS. 4 and 5 show a schematic partial cross-sectional view and a schematic view, respectively, of a seal ring according to one embodiment of the present invention;

FIGS. 6 and 7 show a schematic partial cross-sectional view and a schematic view, respectively, of a seal ring according to one embodiment of the present invention;

figure 8 shows a schematic block diagram of a pump group according to one embodiment of the invention;

figure 9 shows a schematic three-dimensional view of the bearing body adjustment of a pump stack according to one embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Fig. 3A to 3C show an example of a seal ring according to an embodiment of the present invention. In one embodiment, the seal ring may comprise a planar seal ring, wherein the sealing face may be planar. In one embodiment, the seal ring 3A may be mounted on an impeller 1 of an apparatus, such as a pump, for rotation with the impeller 1, similar to the impeller seal ring 3 shown in fig. 1. As shown in fig. 3C, the sealing surface of the sealing ring 3A may be provided with one or more grooves 30A. Referring to fig. 1 and 3C, the groove 30A may have a function of pumping liquid toward the outlet side (at B) of the impeller 1 to increase the liquid pressure in the seal ring gap 20, so that the pressure in the seal ring gap 20 versus the radial distance of the gap shows a gently rising broken line (as shown in the pressure profile of fig. 3A).

In one embodiment, the groove 30A may be used to reduce the outlet side fluid pressure of the impeller 1, thereby reducing the pressure differential across the seal ring gap 20 to reduce leakage. The grooves 30A may also serve to enhance the liquid film stiffness, thereby achieving a better bearing effect to improve operational stability. Although not shown in fig. 3C, in some embodiments, the sealing ring 3B shown in fig. 6 may be utilized to reduce the amount of leakage and/or enhance the liquid film stiffness, etc.

Fig. 4 and 5 show an example of a seal ring according to an embodiment of the present invention. Referring to fig. 1 and 4, a seal ring 3A may be mounted on an impeller 1 of an apparatus such as a pump to rotate with the impeller 1. The sealing surface of the sealing ring 3A may be provided with one or more recessed areas 30A. In one embodiment, the recessed areas 30A may be evenly distributed along the center of the seal ring 3A to rotate with the impeller 1 about the axis. Similarly, with reference to fig. 1 and 6, a seal ring 3B may be mounted on the impeller 1 for rotation with the impeller 1, said seal ring 3B being provided with one or more recessed regions 30B which may be evenly distributed along the centre of the seal ring 3B for rotation with the impeller 1 about an axis. In one embodiment, the sealing rings 3A and/or 3B may comprise planar sealing rings, wherein the sealing surface may be planar.

Referring to fig. 1 and 4, the end surface area (corresponding to the sealing surface) of the sealing ring 3A may include a groove area 30A and a sealing dam area 40A, wherein the groove area 30A may be used to pump liquid to the outside of the sealing ring 3A, and the sealing dam area 40A may be used to increase the pressure of the liquid, inhibiting leakage flow. Similarly, referring to fig. 1 and 6, the end face region of the seal ring 3B may include a groove region 30B and a seal dam region 40B.

In one embodiment, the outer profile of the

groove regions

30A and 30B has better hydraulic performance. For example, referring to fig. 1 and 4, when the pump 100 is operated, after the pump 100 is filled with liquid, the sealing ring 3A can rotate with the impeller 1 at high speed, the groove area 30A of the sealing ring 3A can drive the liquid to rotate together, the pump faces the outside of the sealing ring 3A, and the groove area 30A can suck the liquid from the inlet (a) of the impeller 1. In this process, the liquid in the trough area 30A may flow around the inner walls of the trough area 30A, where the liquid acts on the inner walls of the trough area 30A with a lifting force during the circulating motion, which in turn acts on the liquid with a force equal to and opposite to the lifting force. The force of the recessed area 30A acts on the fluid to energize the fluid toward the sealing dam area 40A, thereby impeding leakage flow and/or increasing the stiffness of the fluid film in the gap 20. Similarly, as shown in fig. 6, by providing the groove region 30B and the seal dam region 40B on the seal ring 3B, the circulation of the leakage flow can be blocked, and the rigidity of the liquid film in the gap 20 can also be increased.

As shown in fig. 4 and 6, the end face (seal face) pattern of the seal rings 3A and 3B may include a unidirectional spiral groove 30A and a bidirectional spiral groove 30B, respectively, in the rotational direction. The unidirectional helical groove 30A shown in fig. 4 may be adapted for a single rotational direction, such as the counterclockwise rotational direction shown in fig. 4, but the invention is not limited thereto and other embodiments may utilize other unidirectional helical grooves adapted for a clockwise rotational direction. In one embodiment, the one-way helical groove 30A may comprise an airfoil shape as shown in FIG. 4, but the invention is not limited thereto, and in other embodiments, the groove 30A may utilize other shapes capable of pumping liquid to the outside of the sealing ring 3A to provide a pressurization function and/or to increase the film stiffness of the liquid at the gap of the sealing ring. The bi-directional helical groove 30B shown in fig. 6 may be adapted for both clockwise and counterclockwise rotational directions. In one embodiment, the bi-directional spiral groove 30B shown in FIG. 6 may comprise the airfoil shape shown in FIG. 5, but the invention is not limited thereto, and in other embodiments, the groove 30B may utilize other shapes that pump liquid outward of the seal ring 3B to provide a pressurization function and/or increase the film stiffness of the liquid at the seal ring gap.

In one embodiment, the seal ring gap 20 between the

seal ring

3A or 3B and the casing static seal ring 4 is adjustable to maintain a minimum of the seal ring gap 20 to ensure optimum performance (e.g. using the shim pack 6 described below with reference to fig. 8 and 7). The

sealing ring

3A or 3B has a pressurization function, so that liquid in the sealing ring gap 20 has higher liquid film rigidity, leakage amount can be effectively reduced, axial force of the pump set 100 can be well balanced, and operation stability is improved.

Sealing ring

3A or 3B simple structure easily installs to effectively avoid bumping between sealing

ring

3A or 3B and the quiet sealing ring 4 of casing and rub, prolong the life of sealing ring.

Figure 8 shows a schematic block diagram of a pump unit according to one embodiment of the invention. Figure 9 shows a schematic three-dimensional view of the bearing body adjustment of a pump stack according to one embodiment of the invention. Referring to fig. 8 and 7, in one embodiment, the pump stack 500 may include an impeller 1, a volute 2, a

seal ring

3A or 3B, a pump body seal ring 4, a screw 5, a seal gasket set 6, a stud 7, a nut 8, a bearing body 9, a bolt 10, and/or a bearing bracket 11, etc.

As shown in fig. 8, the

sealing ring

3A or 3B can be fixed to the impeller 1 by means of screws 5, both of which are positioned by means of the spigot. The pump body sealing ring 4 can be fixed on the volute 2 by screws 5. In one embodiment, the seal ring gap 20 between the

seal ring

3A or 3B and the pump body seal ring 4 is adjustable by the seal shim pack 6 between the bearing body 9 and the bearing bracket 11 (as described below with reference to fig. 8 and 7).

Referring to fig. 8 and 7, the connecting flange of the bearing body 9 may be formed with one or more fine-pitch threaded holes 12 (e.g., 2, but the present invention is not limited to the number) and/or one or more bolt through holes 13 (e.g., 8, but the present invention is not limited to the number), and the threaded holes 12 and the bolt holes 13 may be uniformly arranged along the center, respectively. In one embodiment, the bolt 10 can be used to assist the installation and replacement of the shim pack 6, and/or the stud 7 and the nut 8 can be used to fix the bearing body 9 and the shim pack 6 on the bearing bracket 11.

As shown in fig. 9, the shim pack 6 may include one or more shims. In one embodiment, the overall thickness of the adjustable shim packs 7 may be, for example, 5mm, including 2 shims of, for example, 2mm thickness and 1 shim of, for example, 1mm thickness, although the invention is not limited thereto, and in other embodiments, the thickness of the shim packs 6 may be adjusted using shims of various thicknesses. Referring to fig. 8, each shim of the shim pack 6 may include a 4-half split structure, but the present invention is not limited thereto, and each shim may be machined with holes matching the bolt holes 12 and/or the threaded holes 13 on the coupling flange of the bearing body 9. For example, as shown in fig. 9, the shim holes may include rectangular holes or other shapes to mate with the bolt holes 12 and/or threaded holes 13.

Referring to fig. 9, when the adjustment shim pack 6 is installed and replaced, the whole pump unit 500 does not need to be disassembled, and the adjustment shim pack 6 can be directly disassembled and installed from the side by loosening the stud 7 and the nut 8 and matching with the bolt 10. Although not shown in fig. 8, in one embodiment, the seal ring clearance between the

seal ring

3A or 3B and the pump body seal ring 4 may be similarly adjusted using the seal shim pack 6. For example, the gap between the seal rings 3A or 3B and 4 may be adjusted by adding or removing the shim packs 6 or changing the thickness of the shim packs 6. In this way, the seal ring gap can be continuously maintained optimized, ensuring the performance of the pump stack 500. After pump package 500 operation a period, the sealing ring clearance can be because the sealing ring wearing and tearing and grow, and then makes pump package 500's performance deteriorate, can replace the mode of changing the sealing ring through the thickness of adjusting shim group 6 this moment and solve this problem to promote the life of sealing ring.

As described above, according to the embodiments of the present invention, since the sealing ring having a pressurizing function and/or improving the liquid film rigidity of the liquid at the gap of the sealing ring is used, the present invention can effectively reduce the leakage amount and well balance the axial force of the pump set, thereby improving the operation stability. Furthermore, the seal ring clearance between the seal ring and the casing static seal ring is adjustable, so that a minimum seal clearance can be maintained to ensure optimum performance. The invention has simple structure and easy installation, can effectively avoid the collision and friction between the sealing ring and the static sealing ring of the shell, and can also prolong the service life of the sealing ring.

The above description is only an example of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A sealing ring characterised in that one end face of the sealing ring is provided with one or more groove regions for pumping liquid outwardly of the sealing ring and/or a sealing dam region for raising the pressure of the liquid to inhibit leakage flow.

2. A sealing ring according to claim 1, characterized in that the outer contour of the groove area forces the liquid to rotate together when rotating, in order to pump the liquid out of the sealing ring and/or suck it in.

3. The seal ring of claim 1 wherein the groove region is configured to allow fluid in the groove region to flow around an inner wall of the groove region, the inner wall of the groove region being configured to allow fluid to flow toward the seal dam region to impede leakage flow and/or increase the stiffness of the fluid film in the seal gap.

4. A sealing ring according to claim 1 or 2, c h a r a c t e r i z e d in that the groove area comprises one or more one-way spiral grooves and/or one or more two-way spiral grooves, wherein the one-way spiral grooves have an airfoil shape capable of pumping liquid to the outside of the sealing ring and/or the two-way spiral grooves have an airfoil shape capable of pumping liquid to the outside of the sealing ring and/or the grooves are evenly distributed along the centre of the sealing ring.

5. The seal ring according to claim 1 or 2, wherein the seal ring gap is adjusted by adding or removing a shim pack installed between a bearing body and a bearing holder of the pump, or by adjusting a thickness of the shim pack; and/or the sealing ring comprises a planar sealing ring, the end face is a sealing face, and the gasket group comprises one or more gaskets.

6. A pump comprising a seal ring mounted on an impeller, one end face of the seal ring being provided with one or more groove regions for pumping liquid outwardly of the seal ring, and/or a seal dam region for raising the pressure of the liquid to inhibit leakage flow.

7. A pump according to claim 6, wherein the outer profile of the recessed region when rotated with the impeller urges liquid to rotate therewith to pump liquid outwardly of the sealing ring and/or draw liquid in.

8. A pump according to claim 6, wherein the recessed region is adapted to allow fluid in the recessed region to flow around an inner wall of the recessed region when rotating with the impeller, the inner wall of the recessed region being adapted to allow fluid to flow towards the seal dam region to impede the flow of leakage fluid and/or to increase the stiffness of the fluid film in the seal gap.

9. A pump according to claim 6 or 7, wherein the groove area comprises one or more unidirectional spiral grooves and/or one or more bidirectional spiral grooves, wherein the unidirectional spiral grooves have an airfoil shape capable of pumping liquid to the outside of the sealing ring and/or the bidirectional spiral grooves have an airfoil shape capable of pumping liquid to the outside of the sealing ring and/or the grooves are evenly distributed along the centre of the sealing ring; and/or the sealing ring comprises a planar sealing ring, and the end face is a sealing face.

10. A pump according to claim 5 or 6, wherein the pump further comprises one or more of an impeller, a volute, a pump body sealing ring, a bearing body, a bearing support, a shim pack mounted between the bearing body and the bearing support; and/or adjusting the seal ring gap by adding or removing the shim packs or adjusting the thickness of the shim packs, the shim packs including one or more shims.