Protective sleeve for tensioning screw rod of volute seat ring of pump turbine

Abstract

The utility model discloses a pump turbine volute seat ring tensioning screw protection sleeve, which relates to the technical field of hydro-generators, and comprises a fixing pipe, a fixing sleeve and a fixing plate arranged at the bottom of concrete, one end of the fixing plate is provided with a groove for positioning the fixing pipe, one part of the fixing pipe is embedded in the concrete and is fixedly connected with the fixing plate, and the other part of the fixing pipe is fixedly connected with the fixing sleeve. One end, extending out of the concrete, of the fixing pipe is fixedly provided with a connector, the outer wall of the connector is provided with a sealing groove, a sealing ring is arranged in the sealing groove, one end of the fixing sleeve is fixedly connected with the volute seat ring, and the other end of the fixing sleeve is arranged outside the connector in a sleeving mode and is in clearance fit with the connector to form a flexible connecting movable opening capable of moving along the axis of the connector. The center of the fixing plate is provided with a through hole used for the tensioning screw to penetrate out of concrete, and the distance L between the adjacent sealing grooves and the diameter D of the section of the sealing ring meet the condition that L / D = 0.05-0.12. According to the utility model, concrete can be prevented from being in direct contact with the tensioning screw rod, and the protective sleeve can be prevented from being damaged due to stress while the pre-tightening force of the tensioning screw rod is ensured.

Description

Technical Field

[0001] This utility model relates to the field of hydro-generator technology, specifically to a protective sleeve for the tensioning screw of a water pump turbine volute housing seat ring. Background Technology

[0002] During the operation of a hydro-generator unit, the volute housing ring, as the foundation of the turbine, is a critical supporting and pressure-bearing component. It directly bears the weight of components such as the top cover, water guide mechanism, and bearings, as well as the axial water thrust transmitted from the top cover, and transfers the water thrust to the surrounding concrete. This is crucial for the safe and stable operation of the unit. The tensioning screw on the turbine volute housing ring is an important part of the unit. The tensioning screw, through preload, tightens and fixes the volute housing ring, and also provides support within the volute housing ring, helping to distribute and transmit the weight of other components and the water thrust. This prevents the volute housing ring from floating or rotating during concrete pouring, ensuring its stability.

[0003] When pouring concrete for the volute housing ring, a protective sleeve is needed to separate the concrete from the tensioning bolt to prevent contact between the bolt and the concrete. As a key component connecting and securing the volute housing ring, the tensioning bolt's design typically considers material strength, preload, and other factors to ensure its stability and safety. However, when the tensioning bolt is in direct contact with the concrete, due to the significant difference in properties between concrete and metal, the bolt's direct action on the concrete can generate substantial local pressure at the contact point. This can lead to stress concentration on the contact surface, potentially causing excessive local stress on the bolt and resulting in cracks, fractures, and other damage. Furthermore, moisture and chemicals in the concrete may come into contact with the tensioning bolt through capillary action or osmosis, causing electrochemical or chemical corrosion on the bolt surface. This corrosion weakens the bolt's rigidity and strength, affecting its normal use.

[0004] Currently, power plants directly use a long steel pipe to protect the tensioning bolt. This method only protects half of the tensioning bolt, while the other half usually requires a PVC pipe or steel pipe to be divided into two halves to wrap and protect the tensioning bolt. The gaps are connected by welding and sealant. This protection method has the problems of complicated installation, time and labor consumption, and damage to the protective sleeve when the tensioning bolt is pre-tightened.

[0005] Chinese patent document CN203594550U, published on May 14, 2014, discloses a radial tie rod structure for the upper frame of a hydro-generator, comprising: a pad, a retaining washer, a nut, a tensioning screw, and a pre-embedded foundation plate. The pad, retaining washer, and nut fix one end of the tensioning screw to the frame, and the retaining washer and nut fix one end of the tensioning screw to the pre-embedded foundation plate. The main features of this utility model are: the pre-tensioning force of the tensioning screw tightens the upper frame radially, thereby enhancing the radial stiffness of the upper frame; the structure is simple and low-cost; and since the tensioning screw only bears tensile force, it avoids the situation where traditional jack supports damage the foundation in the event of a short circuit in the unit.

[0006] However, with the above technical solution, the tensioning screw acts directly on the concrete, which may cause stress concentration at the contact surface, leading to damage such as cracks, fractures, and corrosion.

[0007] Chinese patent application CN207437261U, published on June 1, 2018, discloses a foundation connection mechanism for a hydro-generator with an inclined boom upper frame. This structure is embedded in a concrete foundation along the positioning direction of the upper frame support arm, with an adjustment hole in the base plate located below the mounting plate. During unit installation, a screw is passed through the open hole in the connecting plate and secured with bolts. One end of the connecting screw is fixed to the threaded hole in the connecting plate, and the other end passes through the open hole in the upper frame end plate of the inclined boom and is secured with an adjusting nut. An axial rectangular groove is provided on the contact surface between the connecting plate and the upper frame end plate, with a combination key driven into the groove. A lifting bolt is installed in the threaded hole of the base plate to lift the upper frame and adjust it to the design elevation.

[0008] However, the above technical solution uses a long steel pipe to protect the tensioning screw. When the volute seat ring is used to protect the tensioning screw, the long steel pipe may break under the pre-tightening force. Utility Model Content

[0009] To solve the above-mentioned technical problems, this utility model proposes a protective sleeve for the tensioning screw of a water pump turbine volute housing seat ring, which can improve the protection of the tensioning screw, prevent direct contact between concrete and the screw, and ensure the preload of the tensioning screw while preventing the protective sleeve from being damaged by stress.

[0010] This utility model is achieved using the following technical solution:

[0011] A protective sleeve for the tensioning screw of a water pump turbine volute housing seat ring includes a fixing pipe, a fixing sleeve, and a fixing plate. The fixing plate is set at the bottom of concrete, and one end of the fixing plate is provided with a groove for positioning the fixing pipe. Part of the fixing pipe is embedded in the concrete and fixedly connected to the fixing plate, and part of it extends out of the concrete. A joint is fixedly provided at the end of the fixing pipe that extends out of the concrete. Several sealing grooves are provided circumferentially on the outer wall of the joint, and a sealing ring is provided in the sealing groove. One end of the fixing sleeve is fixedly connected to the volute housing seat ring, and the other end is sleeved on the joint and forms a flexible connection opening that can move along the joint axis with the joint clearance fit. The center of the fixing plate is provided with a through hole for the tensioning screw to pass through the concrete. The distance L between adjacent sealing grooves and the diameter D of the sealing ring cross section satisfy L / D=0.05-0.12.

[0012] The fixing plate is provided with anchor bars distributed radially.

[0013] The sealing ring is an O-ring.

[0014] The sealing groove has two channels.

[0015] Both the fixing sleeve and the connector's socket end are provided with chamfers, with a chamfer angle of 30°-60° and a chamfer width of 5-8mm.

[0016] The inner wall of the fixing sleeve is provided with a wear-resistant coating.

[0017] The fixing tube, fixing sleeve, and fixing plate are arranged coaxially.

[0018] The joint is welded and fixed to the fixed pipe or fixed to the fixed pipe by threads.

[0019] The fixing sleeve is welded to the seat ring or fixedly connected by a flange.

[0020] The fixing pipe is welded to the fixing plate or fixedly connected by a flange.

[0021] Compared with the prior art, the advantages of this utility model are as follows:

[0022] 1. This utility model, through the flexible connection and clearance fit design, allows the protective sleeve to undergo axial displacement under pre-tightening force, avoiding the breakage accident caused by the traditional rigid protective sleeve due to stress. At the same time, the combination of sealing groove and sealing ring can isolate the surrounding moisture and prevent electrochemical or chemical corrosion of the screw. In addition, the specific spacing between the sealing grooves and the ratio of the diameter of the sealing ring section can ensure a good sealing effect, significantly improving the sealing life of the turbine tensioning screw protective sleeve. Moreover, the structure is simple and convenient for installation and manufacturing.

[0023] 2. In this utility model, the radially distributed anchoring bars greatly enhance the anchoring force between the fixing plate and the concrete, resist the periodic vibration load generated during the operation of the turbine, prevent the protective sleeve from loosening or shifting under long-term vibration, and ensure the axial positioning accuracy of the tensioning screw.

[0024] 3. This utility model uses an O-ring to form a radial compression seal and facilitates the axial movement and circulation of the fixed sleeve, which can effectively improve the service life while ensuring the sealing effect.

[0025] 4. In this utility model, the double sealing grooves form a redundant seal, which can still ensure the effectiveness of the seal when one seal fails.

[0026] 5. In this utility model, both the fixed sleeve and the sleeve end of the connector are provided with chamfers. The chamfer angle is 30°-60° and the chamfer width is 5-8mm, which can improve the assembly alignment accuracy and reduce the scratch rate of the sealing ring during assembly.

[0027] 6. In this utility model, the inner wall of the fixing sleeve is provided with a wear-resistant coating, which can reduce the sliding friction coefficient between the fixing sleeve and the joint and the sealing ring, reduce the axial movement resistance, and improve the sealing life.

[0028] 7. In this utility model, the fixing tube, fixing sleeve and fixing plate are arranged coaxially to ensure that the tensioning screw is subjected to uniform force and to avoid local wear of the protective sleeve caused by uneven load, thereby extending the service life of the overall structure. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the installation arrangement of this utility model;

[0030] Figure 2 This is a schematic diagram of the structure of this utility model;

[0031] Figure 3 for Figure 2 Enlarged view of area A in the middle;

[0032] Marked in the image:

[0033] 1. Fixing pipe; 2. Fixing plate; 3. Connector; 4. Sealing ring; 5. Fixing sleeve; 6. Tensioning screw; 7. Sealing ring; 8. Nut; 9. Spacer; 10. Anchor bar. Detailed Implementation

[0034] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0035] Example 1

[0036] As the most basic embodiment of this utility model, refer to Figures 1-3 A protective sleeve for the tensioning screw of a water pump turbine volute housing seat ring includes a fixing pipe 1, a fixing sleeve 5, and a fixing plate 2. The fixing plate 2 is set at the bottom of the concrete, and one end of the fixing plate 2 is provided with a groove for positioning the fixing pipe 1. Part of the fixing pipe 1 is embedded in the concrete and fixedly connected to the fixing plate 2, and part of it extends out of the concrete. A joint 3 is fixedly provided at the end of the fixing pipe 1 that extends out of the concrete. Two sealing grooves are provided circumferentially on the outer wall of the joint 3, and a sealing ring 4 is provided in the sealing groove. One end of the fixing sleeve 5 is fixedly connected to the volute housing seat ring 7, and the other end is sleeved on the joint 3 and forms a flexible connection opening that can move along the axis of the joint 3 with a clearance fit. The fixing sleeve 5 and the fixing plate 2 are provided with a through hole for the tensioning screw 6 to pass through the concrete. The distance L between adjacent sealing grooves and the diameter D of the sealing ring 4 satisfy L / D=0.05-0.12.

[0037] In this embodiment, a flexible connection is formed by the gap fit between the fixed pipe 1 and the fixed sleeve 5, allowing axial displacement to compensate for thermal expansion and contraction or vibration displacement between the volute seat ring 7 and the concrete; the fit between the sealing groove and the sealing ring 4 prevents water from seeping into the tensioning screw 6 area and protects the screw from corrosion; at the same time, the specific spacing between the sealing grooves and the ratio of the diameter of the sealing ring 4 section can ensure a good sealing effect and significantly improve the sealing life of the protective sleeve of the turbine tensioning screw 6.

[0038] Example 2

[0039] As another preferred embodiment of this utility model, this embodiment is a further detailed supplement and explanation of the technical solution of this utility model based on the above-described embodiment 1. (Refer to...) Figures 1-3 In this embodiment, the fixing plate 2 is provided with radially distributed anchor bars 10.

[0040] In this embodiment, the radially distributed anchoring bars 10 significantly enhance the anchoring force between the fixing plate 2 and the concrete, resist the periodic vibration load generated during the operation of the turbine, prevent the protective sleeve from loosening or displacing under long-term vibration, and ensure the axial positioning accuracy of the tensioning screw 6.

[0041] Example 3

[0042] As another preferred embodiment of this utility model, this embodiment is a further detailed supplement and explanation of the technical solution of this utility model based on the above-described embodiment 2. (Refer to...) Figures 1-3In this embodiment, the sealing ring 4 is an O-ring, the connector 3 is fixed to the fixing pipe 1 by threads, the fixing sleeve 5 and the seat ring 7 are fixedly connected by flanges, and the fixing pipe 1 and the fixing plate 2 are fixedly connected by flanges.

[0043] In this embodiment, an O-ring is used to form a radial compression seal, which facilitates the axial movement cycle of the fixed sleeve 5. It can still maintain the sealing performance during axial displacement. While ensuring the sealing effect, it can effectively resist wear life. At the same time, the double sealing groove forms a redundant seal, which can still ensure the sealing effectiveness when one seal fails.

[0044] Example 4

[0045] As the preferred embodiment of this utility model, refer to Figures 1-3 A protective sleeve for the tensioning screw of a water pump turbine volute housing seat ring includes a fixing pipe 1, a fixing sleeve 5, and a fixing plate 2. The fixing plate 2 is set at the bottom of the concrete, and one end of the fixing plate 2 is provided with a groove for positioning the fixing pipe 1. Part of the fixing pipe 1 is embedded in the concrete and fixedly connected to the fixing plate 2, and part of it extends out of the concrete. A joint 3 is fixedly provided at the end of the fixing pipe 1 that extends out of the concrete. Two sealing grooves are provided circumferentially on the outer wall of the joint 3, and an O-ring seal 4 is provided in the sealing groove. One end of the fixing sleeve 5 is fixedly connected to the volute housing seat ring 7, and the other end is sleeved on the outside of the joint 3 and forms a flexible connection opening that can move along the axis of the joint 3 with a clearance fit. The fixing sleeve 5 and the fixing plate 2 are provided with a through hole for the tensioning screw 6 to pass through the concrete. The distance L between adjacent sealing grooves and the diameter D of the sealing ring 4 satisfy L / D=0.12.

[0046] The fixing plate 2 is provided with radially distributed anchor bars 10.

[0047] Both the fixed sleeve 5 and the connector 3 have chamfered ends with a chamfer angle of 30°-60° and a chamfer width of 5-8mm.

[0048] The inner wall of the fixing sleeve 5 is provided with a wear-resistant coating.

[0049] The fixing tube 1, fixing sleeve 5 and fixing plate 2 are arranged coaxially.

[0050] The connector 3 is welded and fixed to the fixed pipe 1.

[0051] The fixing sleeve 5 is welded and fixed to the seat ring 7.

[0052] The fixing tube 1 is welded and fixed to the fixing plate 2.

[0053] The installation method and principle of this embodiment are as follows: First, the fixing pipe 1 is welded to the fixing plate 2, and the fixing plate 2 is pre-embedded in the concrete. The joint 3 is welded to the other end of the fixing pipe 1. The fixing sleeve 5 is fitted onto the joint 3. The tensioning screw 6 is passed through the fixing pipe 1 and the fixing sleeve 5 and fixedly connected to the seat ring 7 by threads. At this time, the fixing sleeve 5 is lifted and welded to the seat ring 7. The bottom of the tensioning screw 6 is engaged by the pad 9 and the nut 8. By rotating the nut 8 at the bottom of the tensioning screw 6, a pre-tightening force is generated to tighten and fix the volute seat ring 7, which plays a supporting role in the volute seat ring 7. Since the fixing sleeve 5 is welded to the seat ring 7, the seat ring 7 drives the fixing sleeve 5 to generate axial displacement. Since the fixing sleeve 5 and the joint 3 form a flexible connection due to the clearance fit, the seat ring 7 drives the fixing sleeve 5 to generate axial displacement along the joint 3. The fixing sleeve 5 and the fixing pipe 1 will not break due to force, and can effectively prevent the concrete from contacting the tensioning screw 6.

Claims

1. A protective sleeve for the tensioning screw of a water pump turbine volute housing seat ring, characterized in that: The device includes a fixed pipe (1), a fixed sleeve (5), and a fixed plate (2). The fixed plate (2) is set at the bottom of the concrete, and one end of the fixed plate (2) is provided with a groove for positioning the fixed pipe (1). Part of the fixed pipe (1) is embedded in the concrete and fixedly connected to the fixed plate (2), and part of it extends out of the concrete. The end of the fixed pipe (1) extending out of the concrete is fixedly provided with a joint (3). The outer wall of the joint (3) is provided with several sealing grooves, and a sealing ring (4) is provided in the sealing groove. One end of the fixed sleeve (5) is fixedly connected to the volute seat ring (7), and the other end is sleeved on the joint (3) and is fitted with the joint (3) with a clearance to form a flexible connection opening that can move along the axis of the joint (3). The center of the fixed plate (2) is provided with a through hole for the tensioning screw (6) to pass through the concrete. The distance L between adjacent sealing grooves and the diameter D of the sealing ring (4) satisfy L / D=0.05-0.

12.

2. The protective sleeve for the tensioning screw of the volute housing seat ring of a water pump and turbine according to claim 1, characterized in that: The fixing plate (2) is provided with radially distributed anchor bars (10).

3. A protective sleeve for the tensioning screw of a water pump turbine volute housing seat ring according to claim 1 or 2, characterized in that: The sealing ring (4) is an O-ring (4).

4. The protective sleeve for the tensioning screw of the volute housing seat ring of a water pump and turbine according to claim 3, characterized in that: The sealing groove has two channels.

5. The protective sleeve for the tensioning screw of the volute housing seat ring of a water pump and turbine according to claim 4, characterized in that: Both the fixed sleeve (5) and the connector (3) are provided with chamfers at their socket ends, with a chamfer angle of 30°-60° and a chamfer width of 5-8mm.

6. The protective sleeve for the tensioning screw of the volute housing seat ring of a water pump and turbine according to claim 5, characterized in that: The inner wall of the fixing sleeve (5) is provided with a wear-resistant coating.

7. The protective sleeve for the tensioning screw of the volute housing seat ring of a water pump and turbine according to claim 1, characterized in that: The fixing tube (1), fixing sleeve (5) and fixing plate (2) are coaxially arranged.

8. The protective sleeve for the tensioning screw of the volute housing seat ring of a water pump and turbine according to claim 1, characterized in that: The joint (3) is welded and fixed to the fixed pipe (1) or fixed to the fixed pipe (1) by threads.

9. The protective sleeve for the tensioning screw of the volute housing seat ring of a water pump and turbine according to claim 1, characterized in that: The fixing sleeve (5) is welded to the seat ring (7) or fixedly connected by a flange.

10. The protective sleeve for the tensioning screw of the volute housing seat ring of a water pump and turbine according to claim 1, characterized in that: The fixed pipe (1) is welded to the fixed plate (2) or fixedly connected by a flange.

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