Gap sealing structure of double-suction axially split pump

Abstract

The utility model relates to the field of axially split pumps, in particular to a gap sealing structure of a double-suction axially split pump, which comprises a static sealing ring fixed on the inner side of a pump body and a movable sealing ring fixed on an impeller wear ring, and a radial sealing gap is arranged between the inner wall of the static sealing ring and the outer wall of the movable sealing ring. An inner check ring is formed at the end, close to a low-pressure cavity, of the static sealing ring, an outer boss is formed on the section, close to a high-pressure cavity, of the movable sealing ring, and axial sealing gaps are formed between the inner side of the inner check ring and the end face of the movable sealing ring and between the outer side of the outer boss and the end face of the static sealing ring. The static sealing ring is provided with a vortex pressure reducing part which enables water flow flowing through the radial sealing gap and the axial sealing gap to form vortex. The resistance of water flow passing through the gap is increased, so that the leakage rate is reduced, the operation efficiency of the axially split pump is ensured, and the purposes of energy conservation and consumption reduction are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of split-center pump equipment, in particular to a gap sealing structure for a double-suction split-center pump. Background Art

[0002] Double-suction split case pumps are widely used in water conservancy projects due to their large flow and high head. For large-flow pump equipment, its operating efficiency determines the power consumption of the entire equipment, and the sealing between the impeller and the pump body in the split case pump plays a key role in the operating efficiency.

[0003] The traditional split case pump adopts a single sealing ring structure, that is, the sealing ring is installed on the inside of the pump body and cooperates with the gap of the impeller mouth ring for sealing. The high-pressure water at the impeller outlet (high-pressure chamber) leaks through the sealing gap to the impeller inlet (low-pressure chamber). As the equipment runs, the sealing gap will increase due to wear, resulting in increased pump flow loss, reduced pump efficiency, and increased energy consumption. The current treatment method in the workshop is to widen the sealing ring and the impeller mouth ring along the axial direction by welding. However, this will occupy the installation space of the mechanical seal brackets at both ends of the pump body, and the actual widening amount is limited. Therefore, in order to enhance the sealing reliability, it is necessary to optimize the gap sealing structure of the double-suction split case pump. Utility Model Content

[0004] In order to solve the above-mentioned deficiencies of the prior art, the utility model provides a double-suction split-center pump gap sealing structure, which increases the resistance of water flow through the gap, thereby reducing leakage, ensuring the operating efficiency of the split-center pump, and achieving the purpose of energy saving and consumption reduction.

[0005] The technical solution of the utility model is: a double-suction split pump gap sealing structure, comprising a static sealing ring fixed on the inner side of the pump body and a dynamic sealing ring fixed on the impeller mouth ring, a radial sealing gap is provided between the inner wall of the static sealing ring and the outer wall of the dynamic sealing ring, an inner retaining ring is formed at one end of the static sealing ring close to the low-pressure chamber, an outer boss is formed at a section of the dynamic sealing ring close to the high-pressure chamber, an axial sealing gap is provided between the inner side of the inner retaining ring and the end face of the dynamic sealing ring, and between the outer side of the outer boss and the end face of the static sealing ring, and a vortex decompression portion is provided on the static sealing ring for forming a vortex in the water flow flowing through the radial sealing gap and the axial sealing gap. The setting of double axial sealing gap plus radial sealing gap greatly increases the distance of water leakage process compared with the single radial seal in the prior art, and does not need to occupy the installation space of the original mechanical seal bracket, thereby improving the sealing reliability. At the same time, a vortex pressure relief portion is set on the static sealing ring. The leaked water flow forms a vortex after passing through the vortex pressure relief portion. Due to the rotation of the vortex, a rotating water flow in the opposite direction of the leaked water flow can be formed, thereby weakening the forward energy of the leaked water flow, achieving the effect of pressure relief, and further reducing the leakage amount, thereby ensuring the operating efficiency of the double-suction split pump and maintaining low energy consumption of the split pump during the operating cycle.

[0006] The vortex pressure relief part includes a plurality of annular trapezoidal grooves arranged at intervals along the water flow direction on the end face of the static sealing ring, the inner wall of the static sealing ring and the inner side of the inner retaining ring. The inclined surfaces on both sides of the annular trapezoidal groove respectively form a front guide inclined surface and a rear return inclined surface. After the water flows into the sealing gap along the leakage direction, it enters the trapezoidal groove along the front guide inclined surface of the trapezoidal groove under the skin effect, and forms a low-pressure area in the groove, causing part of the water flow to flow back to form an internal vortex, and the other part of the water flows along the rear guide inclined surface to enter the sealing gap and reach the subsequent trapezoidal groove, so as to achieve stable pressure relief of the water flow.

[0007] An annular convex ridge is formed on the outer side of the outer boss, and the annular convex ridge is arranged corresponding to the annular trapezoidal groove located at the end surface of the static sealing ring, and a labyrinth-shaped gap is formed between the annular convex ridge and the annular trapezoidal groove. The labyrinth-shaped gap is arranged on the side close to the high-pressure chamber, and the water flow entering the sealing gap can be confined at the starting position, thereby greatly reducing the leakage amount and leakage pressure of the water flow.

[0008] The outer side of the static seal ring is formed with a convex key corresponding to the key slot opened on the lower middle surface of the pump body, and a pin hole is opened on the outer side of the static seal slot at a position away from the convex key, and the pin hole cooperates with the positioning pin fixed on the upper middle surface of the pump body. The convex key cooperates with the key slot, and the pin hole cooperates with the positioning pin, so that the static seal ring can be detachably installed, which is convenient for later maintenance.

[0009] The outer wall of the static sealing ring is in sealing contact with the open surface of the pump body through the sealing ring. The arrangement of the sealing ring can prevent cavitation from occurring at the arc-shaped part of the pump body where the static sealing ring is fixed, thereby playing a role in suppressing water energy loss.

[0010] A sealing groove for installing the sealing ring is provided on the outer wall of the static sealing ring outside the convex key.

[0011] The beneficial effects of the utility model are as follows: this scheme greatly increases the distance of the water leakage process by setting a double axial sealing gap plus a radial sealing gap, compared with the single radial seal in the prior art, and does not need to occupy the installation space of the original mechanical seal bracket, thereby improving the sealing reliability. At the same time, a vortex pressure relief portion is set on the static sealing ring, and the leaking water flow forms a vortex after passing through the vortex pressure relief portion. Due to the rotation of the vortex, a rotating water flow in the opposite direction to the leaking water flow can be formed, thereby weakening the forward energy of the leaking water flow, achieving the effect of pressure relief, and further reducing the leakage amount, thereby ensuring the operating efficiency of the double-suction split pump and maintaining a low energy consumption of the split pump during the operating cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of the utility model applied in a double-suction split-center pump;

[0013] Figure 2 yes Figure 1A partial enlarged view of middle A;

[0014] Figure 3 It is a structural schematic diagram of the static sealing ring in the utility model;

[0015] Figure 4 It is a structural schematic diagram of the dynamic sealing ring in the utility model.

[0016] Figure numerals: 1. pump body; 101. high-pressure chamber; 102. low-pressure chamber; 103. lower middle open surface; 2. impeller; 3. pump shaft; 4. mechanical seal bracket; 5. static sealing ring; 501. inner retaining ring; 502. annular trapezoidal groove; 503. convex key; 504. pin hole; 505. sealing groove; 6. dynamic sealing ring; 601. outer boss; 602. annular convex ridge; 603. screw groove; 7. sealing ring. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the technical solution in the utility model, the technical solution in the utility model is clearly and completely described below in conjunction with the accompanying drawings. Other embodiments obtained by those skilled in the art without making any creative work should all fall within the protection scope of the utility model.

[0018] In the present application, the double-suction split-center pump includes a pump body 1, a pump shaft 3 rotatably mounted in the pump body 1, and an impeller 2 fixed to the pump shaft 3 by a key. The installation structure of the above components is the same as that of the prior art and will not be described in detail.

[0019] like Figure 1 As shown, the utility model provides a double-suction split pump gap sealing structure, including a static sealing ring 5 fixed on the inner side of a pump body 1 and a dynamic sealing ring 6 fixed on the impeller 2. Figure 4 As shown, one end of the dynamic seal ring 6 is provided with four screw grooves 603 along the circumferential direction, and is fixed by saddle screws after the impeller 2 mouth rings are aligned. Figure 3 As shown, a convex key 503 corresponding to the keyway on the lower center open surface 103 of the pump body 1 is formed on the outer side of the static sealing ring 5, and a pin hole 504 is opened on the outer side of the static sealing groove 505 at a position away from the convex key 503, and the pin hole 504 cooperates with the positioning pin on the upper center open surface of the pump body 1, thereby realizing the detachable installation of the dynamic sealing ring 6 and the static sealing ring 5.

[0020] like Figure 2As shown, there is a radial sealing gap between the inner wall of the static sealing ring 5 and the outer wall of the dynamic sealing ring 6, an inner retaining ring 501 is formed at one end of the static sealing ring 5 close to the low-pressure chamber 102, and an outer boss 601 is formed at a section of the dynamic sealing ring 6 close to the high-pressure chamber 101, and an axial sealing gap is formed between the inner side of the inner retaining ring 501 and the end face of the dynamic sealing ring 6, and between the outer side of the outer boss 601 and the end face of the static sealing ring 5. The setting of the double axial sealing gap plus the radial sealing gap greatly increases the water leakage process compared with the single radial seal in the prior art. distance, and there is no need to occupy the installation space of the original mechanical seal bracket 4, thereby improving the sealing reliability; at the same time, the static seal ring 5 has a vortex pressure relief portion for forming a vortex in the water flowing through the radial sealing gap and the axial sealing gap. The leaked water entering the sealing gap forms a vortex after passing through the vortex pressure relief portion. Due to the rotation of the vortex, a rotating water flow in the opposite direction to the leakage water flow can be formed, thereby weakening the forward energy of the leakage water flow, achieving the effect of pressure relief, and further reducing the leakage, thereby ensuring the operating efficiency of the double-suction split pump and maintaining a low energy consumption of the split pump during the operating cycle.

[0021] The vortex pressure relief part includes a plurality of annular trapezoidal grooves 502 arranged at intervals along the water flow direction on the end face of the static sealing ring 5, the inner wall of the static sealing ring 5 and the inner side of the inner retaining ring 501. The inclined surfaces on both sides of the annular trapezoidal groove 502 respectively form a front guide inclined surface and a rear return inclined surface. After the water flows into the sealing gap along the leakage direction, it enters the trapezoidal groove along the front guide inclined surface of the trapezoidal groove under the skin effect, and forms a low-pressure area in the groove, causing part of the water to flow back to form an internal vortex, and the other part of the water flows along the rear guide inclined surface to enter the sealing gap and reach the subsequent trapezoidal groove, so as to achieve a stable step-by-step pressure relief of the water flow.

[0022] Further preferably, an annular convex ridge 602 is formed on the outer side of the outer boss 601, and the annular convex ridge 602 is arranged corresponding to the annular trapezoidal groove 502 located at the end surface of the static sealing ring 5, and a labyrinth-shaped gap is formed between the annular convex ridge 602 and the annular trapezoidal groove 502. The labyrinth-shaped gap is arranged on the side close to the high-pressure chamber 101, and the water flow entering the sealing gap can be beamed at the starting position, thereby greatly reducing the leakage amount and leakage pressure of the water flow.

[0023] In order to prevent cavitation from occurring at the arc-shaped portion of the pump body 1 where the static seal ring 5 is fixed and to suppress water energy loss at this location, the outer wall of the static seal ring 5 is in sealing contact with the open surface of the pump body 1 via the seal ring 7. Figure 3 As shown, a sealing groove 505 for installing the sealing ring 7 is opened on the outer wall of the static sealing ring 5 outside the convex key 503 , and there are two corresponding sealing grooves 505 and two sealing rings 7 symmetrically distributed on both sides of the convex key 503 .

[0024] The gap sealing structure of the present application is installed between the pump body 1 and the impeller 2 of the double-suction split-center pump. Through the joint action of the lengthened distance of the three-section sealing gap, the eddy pressure reduction of the annular trapezoidal groove 502 along the water leakage direction and the beam flow of the labyrinth-shaped gap at the initial position of the high-pressure chamber 101, compared with the limited welding widening in the prior art, it can more effectively increase the resistance of water flow through the gap, thereby reducing the leakage, ensuring the operating efficiency of the split-center pump, and achieving the purpose of energy saving and consumption reduction.

[0025] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A double-suction split pump gap sealing structure, comprising a static sealing ring fixed inside the pump body and a dynamic sealing ring fixed on the impeller mouth ring, wherein a radial sealing gap is provided between the inner wall of the static sealing ring and the outer wall of the dynamic sealing ring, and characterized in that: An inner retaining ring is formed at one end of the static sealing ring close to the low-pressure chamber, and an outer boss is formed at a section of the dynamic sealing ring close to the high-pressure chamber. An axial sealing gap is provided between the inner side of the inner retaining ring and the end face of the dynamic sealing ring, and between the outer side of the outer boss and the end face of the static sealing ring. The static sealing ring is provided with a vortex decompression portion for forming a vortex in the water flow passing through the radial sealing gap and the axial sealing gap.

2. The double-suction split-center pump gap sealing structure according to claim 1, characterized in that: The eddy current pressure reducing portion comprises a plurality of annular trapezoidal grooves which are arranged at intervals along the water flow direction on the end face of the static sealing ring, the inner wall of the static sealing ring and the inner side of the inner retaining ring.

3. The double-suction split-center pump gap sealing structure according to claim 2, characterized in that: An annular convex ridge is formed on the outer side of the outer boss, and the annular convex ridge is arranged corresponding to the annular trapezoidal groove located at the end surface of the static sealing ring, and a labyrinth-shaped gap is formed between the annular convex ridge and the annular trapezoidal groove.

4. The double-suction split-center pump gap sealing structure according to any one of claims 1 to 3, characterized in that: A convex key corresponding to the keyway provided on the lower center surface of the pump body is formed on the outer side of the static sealing ring, and a pin hole is provided on the outer side of the static sealing groove away from the convex key, and the pin hole cooperates with a positioning pin fixed on the upper center surface of the pump body.

5. The double-suction split-center pump gap sealing structure according to claim 4, characterized in that: The outer wall of the static sealing ring is in sealing contact with the open surface in the pump body through the sealing ring.

6. The double-suction split-center pump gap sealing structure according to claim 5, characterized in that: A sealing groove for installing the sealing ring is provided on the outer wall of the static sealing ring outside the convex key.

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