Leakage stopping device for pump turbine

Abstract

The utility model provides a leakage stopping device for a pump turbine, which comprises a flow guide ring, the flow guide ring is arranged at the top of an adjusting system of the pump turbine, an impeller is rotatably arranged in the flow guide ring, an output shaft capable of extending out of the flow guide ring is arranged in the middle of the top surface of the impeller, and the top of the output shaft is connected with a connecting shaft through a flange piece; the top of the connecting shaft is connected with a driving device; the sealing assembly is arranged between the impeller and the flow guide ring and used for sealing the position between the impeller and the flow guide ring, and the sealing assembly comprises an upper sealing ring and a lower sealing ring; the upper sealing ring is arranged on the inner top wall of the flow guide ring, and the bottom of the lower sealing ring is arranged on the top of the impeller, connected with the upper sealing ring in a clamped mode and capable of rotating in the upper sealing ring in the circumferential direction. The situation that gaps are generated between the impeller and the flow guide ring and water leaks in the running process of the pump turbine is avoided, so that the sealing performance between the flow guide ring and the impeller in the running process of the pump turbine is improved, and then normal running of the pump turbine is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water pump turbine, in particular to a leakage stop device for water pump turbine. BACKGROUND

[0002] Water pump turbine is a new type of pumped storage unit appeared in 1930s, compared with the pumped storage unit connected with water turbine and water pump in series, its weight is greatly reduced, and the cost is reduced, so it is widely used. Water pump turbine is mainly divided into mixed flow type, inclined flow type and tubular type, and the range of applicable water head / lift is different. Mixed flow type and inclined flow type water pump turbine are mainly applied to large and medium-sized pumped storage power stations, among which the mixed flow type water pump turbine is the most widely used. The tubular type is mainly applied to tidal power stations.

[0003] In the operation process of water pump turbine, in order to ensure the normal operation and safety of water pump turbine, it is necessary to seal the water pump turbine, and the existing water pump turbine usually adopts leakage stop ring to seal it. However, due to the continuous erosion of water flow and the wear of unit components, the sealing gap of leakage stop ring will change, which will lead to the increase of leakage amount. This not only affects the efficiency of the unit, but also may cause pressure loss and uneven pressure distribution. If the sealing gap is too large, water flow will leak through these gaps, which may cause strong pressure pulsation, further transmitted to other parts of the water pump turbine (such as top cover, shafting, etc.), causing vibration, and even damaging the parts. Based on this, the present application provides a leakage stop device for water pump turbine. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a leakage stop device for water pump turbine to solve the technical problems described in the background.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] The present application provides a leakage stop device for water pump turbine, comprising:

[0007] The guide ring is arranged at the top of the regulating system of the water pump turbine, and the impeller is rotatably arranged in the guide ring. The output shaft is arranged on the top surface of the impeller and can extend out of the guide ring. The flange is connected to the top of the output shaft, and the connecting shaft is connected to the top of the flange. The driving device is connected to the top of the connecting shaft.

[0008] The sealing assembly is arranged between the impeller and the guide ring and is used for sealing the space between the impeller and the guide ring. The sealing assembly comprises an upper sealing ring and a lower sealing ring. The upper sealing ring is arranged on the inner top wall of the guide ring. The lower sealing ring is arranged on the top of the impeller and is connected to the upper sealing ring. The lower sealing ring can rotate around the upper sealing ring.

[0009] Optionally, the upper sealing ring is provided with a first clamping block and a first clamping slot in the circumference.

[0010] The lower sealing ring is provided with a second clamping block matched with the first clamping slot and a second clamping slot matched with the first clamping block in the circumference.

[0011] Optionally, the first clamping block and the second clamping slot are both multiple, the multiple second clamping slots correspond to the multiple first clamping blocks one by one, and the multiple first clamping blocks are arranged at different positions on the upper sealing ring.

[0012] The second clamping block has multiple and the first clamping slot has multiple, the multiple first clamping slots correspond to the multiple second clamping blocks one by one, and the multiple second clamping blocks are arranged at different positions on the lower sealing ring.

[0013] Optionally, the flange piece includes a first flange plate and a second flange plate.

[0014] The first flange plate is arranged at the top end of the output shaft, the second flange plate is arranged at the bottom end of the connecting shaft, the top surface of the first flange plate is provided with a fixing block, the bottom surface of the second flange plate is provided with a fixing through hole, and the fixing block is embedded in the fixing through hole and fixed in the fixing through hole by a limiting piece inserted into the fixing through hole.

[0015] Optionally, the fixing block has multiple, and the multiple fixing blocks are arranged on the top surface of the first flange plate at equal intervals around the output shaft.

[0016] The fixing through hole and the limiting piece both have multiple, and the multiple fixing through holes and the multiple limiting pieces correspond to the multiple fixing blocks respectively.

[0017] Optionally, each limiting piece includes a protective shell, a baffle, a spring and a limiting rod.

[0018] The protective shell is arranged on the top surface of the second flange plate, the baffle is slidingly arranged in the protective shell, the top end and the bottom end of the spring are connected to the inner top surface of the protective shell and the upper surface of the baffle respectively, and the bottom end of the limiting rod penetrates the top of the protective shell, the spring and the baffle in sequence and can be inserted into the fixing through hole to limit the fixing block in the fixing through hole.

[0019] Optionally, the top surface of the first flange plate is provided with a limiting hole corresponding to the limiting rod, and the bottom end of the limiting rod is inserted into the fixing through hole and the limiting hole in sequence after penetrating the baffle to limit the fixing block in the fixing through hole.

[0020] Optionally, the top ends of the plurality of limiting rods are all disposed on the lower surface of the push-pull ring.

[0021] Optionally, both the upper sealing ring and the lower sealing ring are made of high-performance composite materials that are wear-resistant and corrosion-resistant.

[0022] The leak-proof device for water pumps and turbines provided in this application allows water to enter the regulating system through a guide ring during the operation of the water pump and turbine. The regulating system adjusts the angle of water flow impacting the impeller, thereby controlling the impeller's rotational speed. An upper sealing ring on the inner top wall of the guide ring and a lower sealing ring on the top of the impeller achieve a seal between the guide ring and the impeller. The lower sealing ring engages with the upper sealing ring and can rotate circumferentially within the upper sealing ring. In other words, during impeller rotation, the lower sealing ring rotates synchronously with the impeller within the upper sealing ring. The engagement of the lower and upper sealing rings limits the rotation of the lower sealing ring, making its rotation more stable and preventing gaps and leaks between the impeller and guide ring during water pump and turbine operation. This improves the sealing performance between the guide ring and impeller during water pump and turbine operation, thus ensuring the normal operation of the water pump and turbine. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a leak-proof device for a water pump and turbine provided in an embodiment of this application;

[0025] Figure 2 Provided for an embodiment of this application Figure 1 Exploded view of the leak-proof device for a medium-water pump turbine;

[0026] Figure 3 A cross-sectional view of the upper and lower seals provided in an embodiment of this application;

[0027] Figure 4 Provided for an embodiment of this application Figure 3 Enlarged structural diagram at point A;

[0028] Figure 5 This is a schematic diagram of the structure of a limiting member provided in an embodiment of this application.

[0029] In the figure: 100, flow guide ring; 101, impeller; 1011, output shaft; 200, adjusting system; 300, flange; 301, first flange; 3011, fixed block; 302, second flange; 400, connecting shaft; 500, sealing assembly; 501, upper sealing ring; 5011, first clamping block; 502, lower sealing ring; 5021, second clamping block; 600, limiting piece; 601, protective shell; 602, baffle; 603, spring; 604, limiting rod; 700, push-pull ring. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are clearly and completely described below. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by persons of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0031] REFERENCE Figures 1 to 5 The present application provides a leakage stopping device for a water pump water turbine, comprising:

[0032] The flow guide ring 100 is arranged at the top of the adjusting system 200 of the water pump water turbine, and the impeller 101 is rotatably arranged in the flow guide ring 100. The output shaft 1011 is arranged at the top surface of the impeller 101 and can extend out of the flow guide ring 100. The top of the output shaft 1011 is connected with the connecting shaft 400 through the flange 300, and the top of the connecting shaft 400 is used to connect a driving device. The adjusting system 200 is used to adjust the angle of water flow impacting the impeller 101, so as to control the rotating speed of the impeller 101. The adjusting system 200 comprises a hydraulic cylinder and a flow guide plate, and the specific structure can be referred to the adjusting system of the water pump water turbine in the prior art. Therefore, the structure of the adjusting system 200 is not specifically described herein. In addition, the driving device is used to drive the connecting shaft 400 to rotate, and the connecting shaft 400 drives the output shaft 1011 connected thereto to rotate through the flange 300 in the process of rotation. The bottom end of the output shaft 1011 is fixedly connected to the top surface of the impeller 101. Therefore, the output shaft 1011 drives the impeller 101 to rotate in the process of rotation. The driving device can be a generator, a pump driving device, an industrial mechanical equipment, and other energy transmission devices. The specific structure can be selected according to the application scene of the water pump water turbine, and the specific structure is not limited herein.

[0033] The sealing assembly 500 is arranged between the impeller 101 and the guide ring 100 and is used for sealing between the impeller 101 and the guide ring 100, and comprises an upper sealing ring 501 and a lower sealing ring 502; the upper sealing ring 501 is arranged on the inner top wall of the guide ring 100, and the bottom of the lower sealing ring 502 is arranged on the top of the impeller 101 and is clamped with the upper sealing ring 501 and can rotate circumferentially in the upper sealing ring 501. During rotation of the impeller 101, the lower sealing ring 502 clamped with the upper sealing ring 501 can rotate synchronously with the impeller 101 in the upper sealing ring 501, which not only ensures normal operation of the water pump turbine, but also ensures sealing performance between the guide ring 100 and the impeller 101. In addition, the upper sealing ring 501 is fixedly connected to the inner top wall of the guide ring 100, and the lower sealing ring 502 is fixedly connected to the top of the impeller 101.

[0034] The sealing device for the water pump turbine provided in the application is used for sealing between the guide ring 100 and the impeller 101. During operation of the water pump turbine, water enters the adjusting system 200 through the guide ring 100, and the adjusting system 200 adjusts the angle of water flow impacting the impeller 101 to control the rotating speed of the impeller 101. The upper sealing ring 501 arranged on the inner top wall of the guide ring 100 and the lower sealing ring 502 arranged on the top of the impeller 101 are used for sealing between the guide ring 100 and the impeller 101. The lower sealing ring 502 is clamped with the upper sealing ring 501 and can rotate circumferentially in the upper sealing ring 501. That is, during rotation of the impeller 101, the lower sealing ring 502 on the impeller 101 rotates synchronously with the impeller 101 in the upper sealing ring 501. The clamping of the lower sealing ring 502 with the upper sealing ring 501 limits the rotation of the lower sealing ring 502, so that the rotation of the lower sealing ring 502 is more stable. The sealing device avoids the situation that a gap is generated between the impeller 101 and the guide ring 100 and water leaks during operation of the water pump turbine, thereby improving the sealing performance between the guide ring 100 and the impeller 101 during operation of the water pump turbine, and ensuring normal operation of the water pump turbine.

[0035] In some embodiments, referring to Figure 3 and Figure 4 the upper sealing ring 501 in the application is circumferentially provided with a first clamping block 5011 and a first clamping groove; the first clamping block 5011 and the first clamping groove both extend along the circumference of the upper sealing ring 501.

[0036] In addition, the lower sealing ring 502 is circumferentially provided with a second clamping block 5021 matched with the first clamping groove and a second clamping groove matched with the first clamping block 5011. The second clamping block 5021 and the second clamping groove both extend along the circumference of the lower sealing ring 502.

[0037] In the above embodiment, through the arrangement of the first clamping block 5011, the second clamping groove matched with the first clamping block 5011, and the first clamping groove and the second clamping block 5021 matched with the first clamping groove, the second clamping block 5021 on the lower sealing ring 502 rotates circumferentially in the first clamping groove, and the second clamping groove on the lower sealing ring 502 rotates circumferentially around the first clamping block 5011 during the rotation of the lower sealing ring 502 synchronously with the impeller 101, multiple limiting of the circumferential rotation of the lower sealing ring 502 is realized, and the sealing between the flow guide ring 100 and the impeller 101 is ensured.

[0038] In some embodiments, with reference to Figure 3 and Figure 4 In the present application, the first clamping block 5011 and the second clamping groove are both multiple, the multiple second clamping grooves correspond to the multiple first clamping blocks 5011 one by one, and the multiple first clamping blocks 5011 are arranged at different positions on the upper sealing ring 501. Among them, the multiple first clamping blocks 5011 arranged at different positions on the upper sealing ring 501 realize the clamping of the first clamping blocks 5011 and the second clamping grooves at multiple different positions, thereby ensuring the stability of the connection between the lower sealing ring 502 and the upper sealing ring 501. In addition, the second clamping block 5021 has multiple and the first clamping groove has multiple, the multiple first clamping grooves correspond to the multiple second clamping blocks 5021 one by one, and the multiple second clamping blocks 5021 are arranged at different positions on the lower sealing ring 502. Among them, the multiple second clamping blocks 5021 arranged at different positions on the lower sealing ring 502 realize the clamping of the second clamping blocks 5021 and the first clamping grooves at multiple different positions, thereby ensuring the stability of the connection between the lower sealing ring 502 and the upper sealing ring 501.

[0039] In the above embodiment, the number of first clamping blocks 5011, the number of second clamping grooves, the number of second clamping blocks 5021, and the number of first clamping grooves can be set according to the size of the actual upper sealing ring 501 and the lower sealing ring 502, and the present application does not make specific limitations here.

[0040] In some embodiments, with reference to Figure 5The flange 300 in the application includes a first flange plate 301 and a second flange plate 302. Specifically, the first flange plate 301 is arranged at the top end of the output shaft 1011, and the second flange plate 302 is arranged at the bottom end of the connecting shaft 400. The top surface of the first flange plate 301 is provided with a fixing block 3011, and the bottom surface of the second flange plate 302 is provided with a fixing through hole. The fixing block 3011 is embedded in the fixing through hole and fixed in the fixing through hole by the limiting piece 600 extending into the fixing through hole. The size of the fixing through hole is larger than the size of the fixing block and can just accommodate the fixing block 3011 and the limiting piece 600, that is, the fixing block 3011 can rotate in the fixing through hole, and the limiting piece 600 can just limit the fixing block 3011 in the fixing through hole after entering the fixing through hole. This facilitates the installation of the first flange plate 301 and the second flange plate 302 and ensures the stability of the installation of the first flange plate 301 and the second flange plate 302.

[0041] In the above embodiment, the fixing block 3011 on the first flange plate 301 is embedded in the fixing through hole on the second flange plate 302, and the first flange plate 301 is rotated so that the fixing block 3011 on it rotates circumferentially in the fixing through hole until the bottom end of the limiting piece 600 can extend into the fixing through hole to limit the fixing block 3011. In this way, the fixing block 3011 is fixed in the fixing through hole, and the connection of the first flange plate 301 and the second flange plate 302 is more stable.

[0042] In some embodiments, referring to Figures 3 to 5 The fixing block 3011 in the application has a plurality of fixing blocks 3011, which are arranged on the top surface of the first flange plate 301 at equal intervals around the output shaft 1011. The plurality of fixing blocks 3011 improves the stability of the connection of the first flange plate 301 and the second flange plate 302. The number of fixing blocks 3011 can be set according to actual needs, which is not limited in the application.

[0043] The fixing through hole and the limiting piece 600 each have a plurality of fixing through holes and a plurality of limiting pieces 600, which correspond to the plurality of fixing blocks 3011 one by one.

[0044] In the above embodiment, each fixing block 3011 is embedded in the corresponding fixing through hole, and the corresponding limiting piece 600 extends into the fixing through hole to limit the fixing block 3011. The plurality of fixing blocks 3011 and the plurality of fixing through holes and the plurality of limiting pieces 600 corresponding to the plurality of fixing blocks 3011 realize the connection of the first flange plate 301 and the second flange plate 302 at multiple places, and ensure the stability of the connection of the first flange plate 301 and the second flange plate 302.

[0045] In some embodiments, referring to Figure 5Each limiting piece 600 in the application includes a protective shell 601, a baffle 602, a spring 603 and a limiting rod 604; specifically, the protective shell 601 is arranged on the top surface of the second flange plate 302, the baffle 602 is slidingly arranged in the protective shell 601, the top end and the bottom end of the spring 603 are connected to the inner top surface of the protective shell 601 and the upper surface of the baffle 602 respectively, and the bottom end of the limiting rod 604 penetrates the top of the protective shell 601, the spring 603 and the baffle 602 in sequence and can be inserted into the fixing hole to limit the fixed block 3011 in the fixing hole. Among them, a vertical sliding groove is formed in the protective shell 601, and a sliding block matched with the vertical sliding groove is arranged on the baffle 602, so that the vertical connection of the baffle 602 and the protective shell 601 is realized by the vertical sliding of the sliding block in the vertical sliding groove. After the limiting rod 604 and the fixed block 3011 enter the fixing hole at the same time, there is no moving space in the fixing hole, that is, the limiting rod 604 can limit the fixed block 3011 in the fixing hole.

[0046] In the above embodiment, after the fixed block 3011 on the first flange plate 301 is embedded into the corresponding fixing hole, the first flange plate 301 is rotated so that the fixed block 3011 on the first flange plate 301 rotates circumferentially in the fixing hole on the second flange plate 302 until the bottom end of the limiting rod 604 can extend into the fixing hole. The limiting rod 604 is pressed downward so that the limiting rod 604 enters the fixing hole to limit the fixed block 3011, and the baffle 602 fixedly sleeved with the limiting rod 604 moves vertically downward in the protective shell 601 in the process of moving upward, and the spring 603 is in a stretched state, thereby realizing the connection of the first flange plate 301 and the second flange plate 302. When it is needed to disassemble the first flange plate 301 and the second flange plate 302, the limiting rod 604 is pulled out upward from the fixing hole, and the baffle 602 fixedly sleeved with the limiting rod 604 moves vertically upward in the protective shell 601 in the process of moving upward, and the spring 603 is compressed. After the limiting rod 604 is pulled out from the limiting hole, the spring 603 compressed gradually rebounds to a free state and drives the limiting rod 604 to return to the state before being pressed or pulled.

[0047] In some embodiments, with reference to Figure 5 The top surface of the first flange plate 301 in the application is provided with a limiting hole corresponding to the limiting rod 604, and the bottom end of the limiting rod 604 is inserted into the fixing hole and the limiting hole in sequence after penetrating the baffle 602 to limit the fixed block 3011 in the fixing hole.

[0048] In the above embodiment, the bottom end of the limiting rod 604 is inserted into the fixed hole and the limiting hole in sequence after penetrating the baffle 602, which not only fixes the fixed block 3011 in the fixed hole by the limiting rod 604, but also further fixes the first flange plate 301 and the second flange plate 302, so that the first flange plate 301 and the second flange plate 302 are connected more stably.

[0049] In some embodiments, with reference to Figure 5 The top end of each of the plurality of limiting rods 604 in the application is arranged on the lower surface of the push-pull ring 700.

[0050] In the above embodiment, the bottom end of the limiting rod 604 is inserted into the fixed hole and the limiting hole in sequence after penetrating the baffle 602, which not only fixes the fixed block 3011 in the fixed hole by the limiting rod 604, but also further fixes the first flange plate 301 and the second flange plate 302, so that the first flange plate 301 and the second flange plate 302 are connected more stably.

[0051] In some embodiments, the upper sealing ring 501 and the lower sealing ring 502 in the application are made of high-performance composite materials with wear resistance and corrosion resistance. Among them, the high-performance composite material is a composite material with significant mechanical properties and heat resistance, which is composed of high-performance reinforcing materials and high-performance resins and other matrices. Such materials have excellent sealing performance and low friction coefficient, can effectively resist the long-term erosion of water flow and the friction and wear between parts, have strong corrosion resistance, adapt to complex hydraulic environments, thereby prolonging the service life of the upper sealing ring 501 and the lower sealing ring 502, ensuring the sealing between the guide ring 100 and the impeller 101 during the operation of the water pump water turbine, and avoiding water leakage between the guide ring 100 and the impeller 101.

[0052] In the above embodiment, the high-performance composite material can be a polytetrafluoroethylene composite material or a ceramic reinforced composite material, which can be set according to actual needs, and the application does not make specific limitations here.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions described in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A leak-proof device for a water pump turbine, characterized in that, Include: The guide ring (100) is arranged at the top of the adjusting system (200) of the water pump turbine, and the impeller (101) is arranged in rotation in the guide ring (100), the top of the output shaft (1011) of the middle of the top surface of the impeller (101) can extend out of the guide ring (100), the top of the connecting shaft (400) is connected with the connecting shaft (400) through the flange (300), and the top of the connecting shaft (400) is used for connecting the driving device; The sealing assembly (500) is arranged between the impeller (101) and the guide ring (100) and is used for sealing between the impeller (101) and the guide ring (100), and it comprises an upper sealing ring (501) and a lower sealing ring (502); the upper sealing ring (501) is arranged on the inner top wall of the guide ring (100), and the bottom of the lower sealing ring (502) is arranged on the top of the impeller (101) and is clamped with the upper sealing ring (501) and can rotate circumferentially in the upper sealing ring (501).

2. The water-tight apparatus for a pump-turbine according to claim 1, characterized by The upper sealing ring (501) is circumferentially provided with a first clamping block (5011) and a first clamping groove; The lower sealing ring (502) is circumferentially provided with a second clamping block (5021) matched with the first clamping groove and a second clamping groove matched with the first clamping block (5011).

3. The water-tight apparatus for a pump-turbine according to claim 2, characterized by The first clamping block (5011) and the second clamping groove are both multiple, multiple second clamping grooves correspond to multiple first clamping blocks (5011), and multiple first clamping blocks (5011) are arranged at different positions on the upper sealing ring (501); The second clamping block (5021) has multiple and the first clamping groove has multiple, multiple first clamping grooves correspond to multiple second clamping blocks (5021), and multiple second clamping blocks (5021) are arranged at different positions on the lower sealing ring (502).

4. The water-tight apparatus for a pump-turbine according to claim 1, wherein The flange (300) comprises a first flange (301) and a second flange (302); The first flange (301) is arranged at the top end of the output shaft (1011), the second flange (302) is arranged at the bottom end of the connecting shaft (400), the top surface of the first flange (301) is provided with a fixing block (3011), the bottom surface of the second flange (302) is provided with a fixing through hole, and the fixing block (3011) is embedded in the fixing through hole and fixed in the fixing through hole by the limiting piece (600) extending into the fixing through hole.

5. The water-tight apparatus for a pump-turbine according to claim 4, characterized by The fixing block (3011) has multiple, and multiple fixing blocks (3011) are arranged on the top surface of the first flange (301) at equal intervals around the output shaft (1011); The fixing through hole and the limiting piece (600) are both multiple, and multiple fixing through holes and multiple limiting pieces (600) correspond to multiple fixing blocks (3011) respectively.

6. The water-tight apparatus for a pump-turbine according to claim 5, wherein Each of the limiting members (600) comprises a protective shell (601), a baffle (602), a spring (603) and a limiting rod (604); The protective shell (601) is arranged on the top surface of the second flange plate (302), the baffle (602) is slidingly arranged in the protective shell (601), the top end and the bottom end of the spring (603) are connected to the inner top surface of the protective shell (601) and the upper surface of the baffle (602) respectively, and the bottom end of the limiting rod (604) penetrates the top of the protective shell (601), the spring (603) and the baffle (602) in sequence and can be inserted into the fixing hole to limit the fixing block (3011) in the fixing hole.

7. The water-tight apparatus for a pump-turbine according to claim 6, wherein The top surface of the first flange plate (301) is provided with a limiting hole corresponding to the limiting rod (604), and the bottom end of the limiting rod (604) is inserted into the fixing hole and the limiting hole in sequence after penetrating the baffle (602) to limit the fixing block (3011) in the fixing hole.

8. The water-tight apparatus for a pump-turbine according to claim 6, wherein The top ends of the plurality of limiting rods (604) are arranged on the lower surface of a push-pull ring (700).

9. The leakage preventing apparatus for a pump-turbine according to any one of claims 1 to 8, characterized in that, The upper sealing ring (501) and the lower sealing ring (502) are made of polytetrafluoroethylene composite material or ceramic reinforced composite material.

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