A sealing structure for the main shaft of a water turbine

Abstract

This utility model discloses a turbine main shaft sealing structure. The turbine has a shell with two inlets, and the end of the shell furthest from the inlets is the outlet. The shell is used for water diversion. A bracket is installed inside the shell, and the main shaft is mounted on the bracket. Several bearings are arranged between the bracket and the main shaft. A blade is installed on the main shaft at the outlet. A water-proof sleeve is installed inside the shell, sleeved on the main shaft. One end of the water-proof sleeve abuts against the bracket, and the other end extends out of the shell. A first water seal structure is provided between the blade and the bracket. The turbine main shaft sealing structure, through dynamic liquid film sealing, integrated structural design, and the application of low-friction materials, achieves efficient and long-life waterproof performance while ensuring flexible rotation of the main shaft. It is especially suitable for turbine scenarios with complex working conditions such as high sediment and high head.

Description

Technical Field

[0001] This utility model relates to the field of water turbine technology, and in particular to a sealing structure for the main shaft of a water turbine. Background Technology

[0002] As the core equipment for converting water energy into mechanical energy, the operational reliability of a water turbine is directly affected by its sealing performance. Traditional water turbine designs suffer from the following technical defects in the waterproofing structures of dynamic sealing components such as the main shaft and casing, and the blades and supports:

[0003] Traditional mechanical seals rely on end-face friction to achieve sealing. After long-term operation, the sealing surface wears out severely, requiring frequent replacement and resulting in high maintenance costs. When using packing or other filler seals, high-pressure water can easily seep out from the gap between the packing and the main shaft, leading to lubrication failure and bearing corrosion.

[0004] To address the aforementioned issues, this utility model proposes a water turbine with a highly efficient waterproof structure. Through a dynamically adaptable sealing component design, it achieves a reliable seal with low friction and long service life while ensuring flexible rotation of the main shaft, making it particularly suitable for water diversion scenarios under various operating conditions. Utility Model Content

[0005] This utility model provides a sealing structure for the main shaft of a water turbine to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A sealing structure for the main shaft of a water turbine is disclosed. The water turbine has a casing with two inlets, and the end of the casing furthest from the inlets is a drain outlet. The casing is used for guiding water flow. A support is installed inside the casing, and the main shaft is mounted on the support. Several bearings are installed between the support and the main shaft. A blade is installed on the main shaft at the drain outlet. A water-proof sleeve is installed inside the casing, and the water-proof sleeve is sleeved on the main shaft. One end of the water-proof sleeve abuts against the support, and the other end of the water-proof sleeve extends out of the casing. A first water seal structure is provided between the blade and the support.

[0008] Preferably, the blade is provided with a connecting ring, the bracket is provided with a groove for accommodating the connecting ring, and the first water seal structure is provided between the connecting ring and the groove.

[0009] Preferably, the first water seal structure includes a fixed strip circumferentially disposed on the bracket and a rotating strip sleeved on the end of the blade. The fixed strip has an arc-shaped groove, and the rotating strip has a waterproof protrusion adapted to the arc-shaped groove. The waterproof protrusion is rotatably disposed in the arc-shaped groove.

[0010] Preferably, a clamping housing is provided on the main shaft. The clamping housing is located at the end of the blade away from the support. A through hole is opened at the end of the clamping housing away from the blade, and a screw is inserted in the through hole. A threaded blind hole is opened at the end of the main shaft near the clamping housing. The screws are sequentially inserted into the clamping housing and are threadedly connected to the main shaft.

[0011] Preferably, a second water seal mechanism is provided between the water-proof sleeve and the shell. The second water seal mechanism includes a positioning sleeve and sealing strips provided on both sides of the positioning sleeve. The positioning sleeve is integrally formed on the water-proof sleeve and is connected to the shell with a clearance fit.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] This utility model discloses a sealing structure for a turbine main shaft. Its first water seal structure forms a dynamic liquid film seal through the rotational engagement of a waterproof protrusion and a groove, reducing leakage between the blades and the support. The second water seal mechanism, through a clearance fit and combination with sealing strips on both sides, blocks the seepage path between the water-proof sleeve and the housing, achieving a synergistic effect of static and dynamic sealing. The waterproof protrusion and groove employ a non-contact rotational design to avoid end-face friction and reduce wear on the seals. The flexible contact design between the sealing strips and the positioning sleeve adapts to the thermal deformation and vibration of the main shaft, extending the service life of the sealing assembly.

[0014] In summary, the utility model achieves efficient and long-life waterproof performance while ensuring flexible rotation of the main shaft through dynamic liquid film sealing, integrated structural design and application of low-friction materials. It is especially suitable for water turbine scenarios with complex working conditions such as high sediment and high water head. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a front view of the present invention;

[0017] Figure 3 yes Figure 2 Sectional view of section AA;

[0018] Figure 4 yes Figure 3 A magnified view of a section at point B in the middle;

[0019] Figure 5 This is a schematic diagram of the internal structure of this utility model.

[0020] In the diagram: 1-Shell; 2-Inlet; 3-Bracket; 4-Main shaft; 5-Bearing; 6-Blade; 7-Waterproof sleeve; 8-Connecting ring; 9-Groove; 10-Fixing strip; 11-Rotating strip; 12-Pressure housing; 13-Screw; 14-Positioning sleeve; 15-Sealing strip. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model. Example

[0022] like Figures 1-5 The diagram shows a turbine main shaft sealing structure. The turbine has a housing 1 with two inlets 2. The end of the housing 1 away from the inlets 2 is the outlet. The housing 1 is used for guiding water flow. A bracket 3 is installed inside the housing 1. A main shaft 4 is installed on the bracket 3. Several bearings 5 ​​are installed between the bracket 3 and the main shaft 4. A blade 6 is installed on the main shaft 4 at the outlet. A water-proof sleeve 7 is installed inside the housing 1. The water-proof sleeve 7 is sleeved on the main shaft 4. One end of the water-proof sleeve 7 abuts against the bracket 3, and the other end of the water-proof sleeve 7 extends out of the housing 1. A first water seal structure is installed between the blade 6 and the bracket 3.

[0023] In this embodiment, the aforementioned housing 1 adopts a dual-inlet structure 2, with water entering the housing 1 symmetrically from both sides. This design balances the water pressure distribution through flow diversion, reducing the impact of high-pressure water flow from one side on the main shaft 4 and the blades 6. Simultaneously, the dual inlets 2 optimize the water flow direction, causing it to more evenly propel the blades 6 to rotate, reducing hydraulic losses. Symmetrical water intake reduces water flow turbulence, improving the efficiency of water energy conversion to mechanical energy; balanced water pressure reduces vibration of the main shaft 4, extending the life of the bearings 5 ​​and seals; and it adapts to high-head or sediment-laden water flows, reducing the risk of localized cavitation at the blades 6.

[0024] Furthermore, the aforementioned bracket 3 is fixed inside the housing 1. Water flowing through the housing 1 can pass through the bracket 3 and support the main shaft 4 via several bearings 5. The bearings 5 ​​reduce the frictional resistance during the rotation of the main shaft 4, while simultaneously bearing radial and axial loads. One end of the main shaft 4 is connected to the blade 6, and the other end can be linked with equipment such as a generator. The bearings 5 ​​ensure smooth rotation of the main shaft 4, reducing seal failure caused by sway; the multi-bearing design distributes the force on the main shaft 4, making it suitable for high torque or high speed conditions; the modular bearing structure facilitates replacement and reduces maintenance costs.

[0025] In this embodiment, the aforementioned water-proof sleeve 7 is fitted onto the outside of the main spindle 4, with one end abutting against the bracket 3 and the other end extending out of the housing 1. Its function is to isolate the water flow inside the housing 1 from the bracket 3 and bearing 5 area, preventing water from entering the gap between the main spindle 4 and the bracket 3, thus preventing corrosion of the bearing 5 or affecting lubrication. It blocks water flow into the bearing 5 area, avoiding lubricant emulsification or bearing 5 corrosion; integrated outside the main spindle 4, it eliminates the need for additional sealing space, reducing the complexity of the housing 1; and its clearance fit with the main spindle 4 allows for thermal expansion and contraction or slight vibration of the main spindle 4.

[0026] Reference Figures 3-5 In some embodiments of this example, a connecting ring 8 is also installed on the blade 6, and a groove 9 for accommodating the connecting ring 8 is provided on the bracket 3. A first water seal structure is disposed between the connecting ring 8 and the groove 9.

[0027] Specifically, a connecting ring 8 is provided at the end of the blade 6, and a corresponding groove 9 is formed in the bracket 3. After the connecting ring 8 is embedded in the groove 9, an initial sealing interface is formed, restricting water flow from directly entering the sealing area. The geometric fit between the groove 9 and the connecting ring 8 reduces water flow impact and reduces leakage; improved installation accuracy and precise alignment ensure the effective operation of subsequent sealing components.

[0028] like Figures 1-5 As shown, in some embodiments of this example, the first water seal structure includes a fixed strip 10 circumferentially disposed on the bracket 3 and a rotating strip 11 sleeved on the end of the blade 6. The fixed strip 10 has an arc-shaped groove, and the rotating strip 11 has a waterproof protrusion adapted to the arc-shaped groove. The waterproof protrusion is rotatably disposed in the arc-shaped groove.

[0029] In this embodiment, the aforementioned fixing strip 10 is circumferentially mounted on the bracket 3, and an arc-shaped groove is formed on its surface. The rotating strip 11 is sleeved on the end of the blade 6, and its surface has waterproof protrusions that are adapted to the arc-shaped groove of the fixing strip 10.

[0030] During operation, as the blade 6 rotates, the protrusions on the rotating strip 11 rotate within the arc-shaped groove of the fixed strip 10, forming a dynamic liquid film seal. The liquid film is filled with water or a lubricating medium, and the sealing pressure is maintained by centrifugal force. The non-contact design reduces friction, and the liquid film between the protrusion and the arc-shaped groove provides both sealing and lubrication; wear life is extended, and friction loss is reduced compared to traditional mechanical seals; the liquid film can flush away particles such as mud and sand, reducing the risk of scratches on the sealing surface.

[0031] like Figure 1-5 As shown, in some embodiments of this example, a clamping shell 12 is provided on the main shaft 4. The clamping shell 12 is located at the end of the blade 6 away from the support 3. A through hole is opened at the end of the clamping shell 12 away from the blade 6, and a screw 13 is inserted through the through hole. A threaded blind hole is opened at the end of the main shaft 4 near the clamping shell 12. The screw 13 is sequentially inserted on the clamping shell 12, and the screw 13 is threadedly connected to the main shaft 4.

[0032] In this embodiment, the aforementioned clamping housing 12 is located at the end of the blade 6 furthest from the support 3, and is connected to the threaded blind hole at the end of the main shaft 4 via a screw 13. After the screw 13 is tightened, the clamping housing applies axial pressure to the blade 6, ensuring tight contact between the connecting ring 8 and the groove 9, and between the rotating bar 11 and the fixed bar 10. By adjusting the preload of the screw 13, the contact stress at the sealing interface is optimized; the split-type clamping housing design simplifies the assembly process of the blade 6 and reduces the difficulty of on-site debugging; the threaded blind hole prevents the screw 13 from protruding, reducing the risk of loosening caused by water flow impact.

[0033] like Figure 1-5 As shown, in some embodiments of this example, a second water seal mechanism is provided between the water-proof sleeve 7 and the housing 1. The second water seal mechanism includes a positioning sleeve 14 and sealing strips 15 disposed on both sides of the positioning sleeve 14. The positioning sleeve 14 is integrally formed on the water-proof sleeve 7 and is connected to the housing 1 with a clearance fit.

[0034] In this embodiment, the positioning sleeve 14 and the water-proof sleeve 7 are integrally formed and are fitted with the housing 1 with a clearance fit; the sealing strip 15 is disposed on both sides of the positioning sleeve 14.

[0035] When the water-tight sleeve 7 shifts slightly due to vibration or thermal deformation of the main shaft 4, the sealing strip 15 fills the gap through elastic deformation, preventing water from seeping in between the housing 1 and the sleeve. The combination of static and dynamic sealing, with the rigid support of the positioning sleeve 14 ensuring the coaxiality of the main shaft 4, and the flexible contact of the sealing strip 15 adapting to minor movements, results in high tolerance for assembly errors. The material of the sealing strip 15 can be selected according to water quality.

[0036] Preferably, the sealing strip 15 is made of an elastic material, specifically rubber.

[0037] Furthermore, the aforementioned positioning sleeve 14 and the water-proof sleeve 7 are integrally formed by casting or machining, eliminating the assembly gaps of the split structure. The absence of connecting gaps blocks the water seepage path; the integrated design reduces stress concentration and is suitable for high-pressure or impact load conditions.

[0038] Of course, there may be other embodiments of this utility model. Without departing from the spirit and essence of this utility model, those skilled in the art can make various corresponding changes and modifications based on this utility model, but these corresponding changes and modifications should all fall within the protection scope of the appended claims of this utility model.

Claims

1. A sealing structure for the main shaft of a water turbine, wherein the water turbine has a housing (1) with two inlets (2), the end of the housing (1) away from the inlets (2) being a drain outlet, the housing (1) being used for guiding water flow; a bracket (3) is provided inside the housing (1), a main shaft (4) is mounted on the bracket (3), and a plurality of bearings (5) are provided between the bracket (3) and the main shaft (4); a blade (6) is provided on the main shaft (4) at the drain outlet; characterized in that, A water-proof sleeve (7) is provided inside the housing (1). The water-proof sleeve (7) is sleeved on the main shaft (4). One end of the water-proof sleeve (7) abuts against the bracket (3), and the other end extends out of the housing (1). A first water seal structure is provided between the blade (6) and the bracket (3).

2. A seal structure for a water turbine main shaft according to claim 1, wherein The blade (6) is provided with a connecting ring (8), and the bracket (3) is provided with a groove (9) for accommodating the connecting ring (8). The first water seal structure is provided between the connecting ring (8) and the groove (9).

3. A seal structure for a water turbine main shaft according to claim 2, wherein The first water seal structure includes a fixed strip (10) circumferentially arranged on the bracket (3) and a rotating strip (11) sleeved on the end of the blade (6). The fixed strip (10) has an arc-shaped groove, and the rotating strip (11) has a waterproof protrusion adapted to the arc-shaped groove. The waterproof protrusion is rotatably arranged in the arc-shaped groove.

4. A seal structure for a water turbine main shaft according to claim 3, wherein The main shaft (4) is provided with a clamping shell (12). The clamping shell (12) is located at the end of the blade (6) away from the bracket (3). The end of the clamping shell (12) away from the blade (6) has a through hole. A screw (13) is inserted in the through hole. The end of the main shaft (4) near the clamping shell (12) has a threaded blind hole. The screw (13) is inserted through the clamping shell (12) and then threadedly connected to the main shaft (4).

5. A hydro-turbine main shaft seal structure according to claim 4, wherein A second water seal mechanism is provided between the water-proof sleeve (7) and the housing (1). The second water seal mechanism includes a positioning sleeve (14) and sealing strips (15) on both sides of the positioning sleeve (14). The positioning sleeve (14) is integrally formed on the water-proof sleeve (7) and is connected to the housing (1) with a clearance fit.

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