Connection device and adjustment method for turbine shaft and generator shaft of pumped storage power station

Abstract

This invention discloses a connection device and adjustment method for the turbine shaft and generator shaft of a pumped storage power station, comprising a sleeve and multiple flat keys. One end of the turbine shaft is fixed in the sleeve. Multiple first elongated holes are formed on the side wall of the sleeve, evenly distributed circumferentially around the centerline of the sleeve, and each first elongated hole is parallel to the centerline of the sleeve. Each first elongated hole has a second elongated hole on each side. Each first elongated hole and its two second elongated holes are arranged in an I-shape, and each first elongated hole communicates with its two second elongated holes. A buffer assembly is installed in each second elongated hole. Multiple keyways are formed on the connecting end of the turbine shaft, evenly distributed circumferentially around the centerline of the turbine shaft. The buffer assembly reduces vibration and prevents axial external forces from directly acting on the connection between the turbine shaft and the generator shaft, thus mitigating the damage to the unit caused by turbine lifting.

Description

Technical Field

[0001] This invention belongs to the technical field of hydropower equipment, specifically relating to a connection device and adjustment method for the turbine shaft and generator shaft of a pumped storage power station. Background Technology

[0002] Pumped storage power stations, also known as pumped-storage hydroelectric power stations, are hydroelectric power stations that use electricity generated during periods of low electricity load to pump water into an upper reservoir and release it into a lower reservoir to generate electricity during periods of high electricity load.

[0003] Pumped storage power stations have the advantages of peak shaving and valley filling, and can be started and stopped quickly as well as operate under varying loads. However, frequent start-ups and shutdowns and low-load operation can cause severe vibrations in the unit, affecting its safe and stable operation and reducing its service life. In some transition processes, it can even cause a "lifting" phenomenon. That is, when the unit loses load, the pressure in the tailrace pipe drops sharply, and the water flows backward in pump mode, generating a huge reverse axial force. When the axial force increases to a critical value, the rotating parts of the unit are lifted to a certain height. During this process, it can even cause serious damage to the impeller blades, leading to loosening and falling off of the bolts at the main shaft connection, resulting in a major safety accident.

[0004] Currently, the conventional connection method is to use an external flange to connect the turbine shaft and the generator shaft. The performance of the flange bolt connection structure is an important component of the overall characteristics of the turbine generator, and sometimes it can even become a weak point that leads to overall structural failure. In the circumferential direction of the main shaft, the bolts are prone to shear deformation. In the axial direction, when the unit experiences a lifting phenomenon, under the huge axial force, the bolts at the shaft connection are prone to tensile deformation due to the lack of buffer, causing the bolts to loosen or even fall off, creating a huge safety hazard. Summary of the Invention

[0005] The purpose of this invention is to provide a connection device and adjustment method for the turbine shaft and generator shaft of a pumped storage power station, which solves the technical problem in the prior art where the bolts of the external flange connection are prone to loosening or even falling off when the unit experiences a lifting phenomenon, resulting in safety hazards for the unit.

[0006] The solution adopted by this invention to solve its technical problem is:

[0007] A connection device for the turbine shaft and generator shaft of a pumped storage power station includes a sleeve and multiple flat keys. One end of the turbine shaft is inserted into and fixed in the sleeve. Multiple first elongated holes are formed on the side wall of the sleeve, evenly distributed circumferentially around the centerline of the sleeve, and each first elongated hole is parallel to the centerline of the sleeve. Each first elongated hole has a second elongated hole at each end. Each first elongated hole and its two second elongated holes at both ends are arranged in an I-shape, and each first elongated hole communicates with its two second elongated holes on both sides. A buffer assembly is installed in each second elongated hole. Multiple keyways are formed on the connecting end of the generator shaft, evenly distributed circumferentially around the centerline of the turbine shaft. After the turbine shaft and generator shaft are connected, the connecting end of the generator shaft is inserted into the sleeve, and each flat key is embedded in the corresponding first elongated hole and keyway, with each flat key contacting the corresponding buffer assembly at both ends.

[0008] By incorporating a sleeve, a flat key, a first elongated hole, and a keyway, the turbine shaft and generator shaft are connected via the fit of the flat key and keyway. This improved connection method allows for better torque transmission in the circumferential direction. Furthermore, by incorporating a buffer assembly and a second elongated hole, when a turbine lift occurs, the axial force acts on the buffer assembly. The buffer assembly's cushioning effect reduces vibration and prevents the axial force from directly acting on the connection between the turbine shaft and generator shaft. Therefore, the damage caused by turbine lift to the unit can be mitigated, and safety hazards can be reduced accordingly.

[0009] Furthermore, the buffer assembly includes a first base plate, a second base plate, and at least one buffer unit; each second elongated hole has two sidewalls along its length, one near the first elongated hole and referred to as the first sidewall; the other is referred to as the second sidewall; the first base plate and the second base plate are inserted into the second elongated holes parallel to each other, the first base plate being parallel to and in contact with the first sidewall, and the second base plate being parallel to and in contact with the second sidewall; the buffer unit is located between the first base plate and the second base plate, and both ends of the buffer unit are connected to the first base plate and the second base plate, respectively.

[0010] Furthermore, each buffer assembly is provided with two buffer units, which are symmetrically arranged with the center line of the first elongated hole along its length as the axis of symmetry; each buffer unit includes a first sleeve and a second sleeve; the first sleeve is fixed to the side of the first base plate near the second base plate; the second sleeve is fixed to the side of the second base plate near the first base plate; a shaft is provided between the first sleeve and the second sleeve; the two ends of the shaft are respectively inserted into the second sleeve and the first sleeve; a spring is sleeved on the shaft, and the two ends of the spring are in contact with the second sleeve and the first sleeve respectively.

[0011] A first base plate, a second base plate, a first sleeve, and a second sleeve are provided for mounting a shaft and a spring; the shaft is used to limit the spring, allowing the spring to extend and retract along the length of the shaft.

[0012] Furthermore, the buffer unit also includes a disc spring, which is located in the second sleeve, with its two ends contacting the shaft core and the second base plate, respectively.

[0013] By adding disc springs, the vibration damping effect of the buffer assembly can be further enhanced.

[0014] Furthermore, the height of the second sleeve is twice the length of the disc spring, and the height of the disc spring is the same as the length of the first sleeve.

[0015] The above restrictions prevent the two ends of the shaft from detaching from the first and second sleeves.

[0016] The number of the first elongated hole, the flat key, and the keyway are all 6, while the number of the buffer assembly and the second elongated hole are both 12.

[0017] With the above restrictions, a keyway and a corresponding flat key are arranged at every 60° on the connecting end of the generator shaft, so that when the turbine shaft and the generator shaft are connected, they are connected in the circumferential direction by 6 flat keys.

[0018] Furthermore, the turbine shaft and casing are integrally formed.

[0019] The adjustment method for the turbine shaft and generator shaft connection device used in pumped storage power stations, as described above, includes the following steps:

[0020] Step 1: Insert one end of the generator shaft into the sleeve, then embed each flat key into the corresponding first elongated hole and keyway, and install a buffer assembly in each second elongated hole to connect the turbine shaft and the generator shaft; both ends of the flat key contact the corresponding buffer assembly respectively;

[0021] Step 2: When the turbine unit of the pumped storage power station vibrates due to the lifting of the turbine, the reverse axial force is greater than the total weight of the rotating parts of the unit. The rotating parts of the unit are lifted to a certain height, that is, the generator shaft is stationary, and the turbine shaft moves in the direction of the generator shaft. The bottom of the buffer component near the generator shaft is squeezed, and the spring on the corresponding side is in a compressed state. At this time, the second bottom plate is in close contact with the second side wall, the disc spring is compressed by the shaft core, and the spring sleeved around the shaft core is compressed by the combination of the first sleeve and the second sleeve.

[0022] When the rotating part of the unit falls back, the buffer component on the side away from the motor shaft is in a compressed state. The compression process is the same as described above, and the buffer process reduces the axial impact force.

[0023] The beneficial effects of this invention are:

[0024] 1. By setting up sleeves, flat keys, first elongated holes and keyways, the turbine shaft and generator shaft are connected through the cooperation of flat keys and keyways. The improved connection method can better transmit torque in the circumferential direction.

[0025] 2. By setting up a buffer assembly and a second elongated hole, when the turbine lifts, the axial external force acts on the buffer assembly. The buffer assembly reduces vibration by buffering, and avoids the axial external force acting directly on the connection between the turbine shaft and the generator shaft. Therefore, the damage of the turbine lift to the unit can be reduced, and the safety hazards will also be reduced accordingly. Attached Figure Description

[0026] Figure 1 A schematic diagram of the overall structure of the present invention is shown.

[0027] Figure 2 A schematic diagram showing the connection relationship between the turbine shaft and the casing is displayed.

[0028] Figure 3 A schematic diagram showing the connection relationship between the generator shaft and the key is displayed.

[0029] Figure 4 A schematic diagram of the buffer component is shown.

[0030] Figure 5 A schematic diagram of the overall structure of the buffer unit is shown.

[0031] The components, parts and their numbers in the figure are as follows: Generator shaft 1, Second elongated hole 11, First elongated hole 12, Sleeve 13, Turbine shaft 2, Flat key 21, Buffer assembly 3, First base plate 31, First sleeve 311, Spring 32, Shaft core 33, Disc spring 34, Second base plate 35, Second sleeve 351, Buffer unit 36. Implementation

[0032] The specific implementation methods of the invention are given below, and the technical solution of the invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the invention. Example

[0033] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, a connection device for a turbine shaft and a generator shaft in a pumped storage power station includes a sleeve 13 and six flat keys 21. One end of the turbine shaft 2 is inserted into and fixed in the sleeve 13, and the two are integrally formed. Six first elongated holes 12 are opened on the side wall of the sleeve 13. The six first elongated holes 12 are evenly distributed around the outer wall of the sleeve 13, and each first elongated hole 12 is parallel to the center line of the sleeve 13. Each first elongated hole 12 has a second elongated hole 11 at each end. Each first elongated hole 12 and the two second elongated holes 11 at its two ends are arranged in an I-shape, and each first elongated hole 12 is connected to the two second elongated holes 11 at its two ends. The generator shaft 1 has 6 keyways on its connecting end, which are evenly distributed around the outer wall of the generator shaft 1. After the turbine shaft 2 and the generator shaft 1 are connected, the connecting end of the generator shaft 1 is inserted into the sleeve 13. Each flat key 21 is embedded in the corresponding first elongated hole 12 and keyway. The two ends of each flat key 21 are in contact with the corresponding buffer assembly 3. The buffer assembly 3 is installed in the corresponding second elongated hole 11.

[0034] In this embodiment, when the connecting end of the generator shaft 1 is inserted into the sleeve 13, the turbine shaft 2 and the generator shaft 1 do not contact each other and there is a gap between them.

[0035] like Figure 5 As shown, the buffer assembly 3 includes a first base plate 31, a second base plate 35, and a buffer unit 36; each second elongated hole 11 is located on two sidewalls along its length, wherein the side closer to the first elongated hole 12 is referred to as the first sidewall; the side farther from the first elongated hole 12 is referred to as the second sidewall; after the buffer assembly 3 is inserted into the second elongated hole 11, the first base plate 31 is parallel to and in contact with the first sidewall, and the second base plate 35 is parallel to and in contact with the second sidewall; the buffer unit 36 ​​is located between the first base plate 31 and the second base plate 35, and the two ends of the buffer unit 36 ​​are respectively connected to the first base plate 31 and the second base plate 35.

[0036] In this embodiment, since the second elongated hole 11 is opened in the circumferential direction of the sleeve 13, the second elongated hole 11 has a certain curvature along its width.

[0037] In this embodiment, each second elongated hole 11 is located on two side walls in its width direction, and each is provided with a sliding groove; each sliding groove is parallel to the axial direction of the sleeve 13; both ends of the first base plate 31 and the second base plate 35 are fixed with sliders, which are slidably disposed in the sliding grooves; by providing sliding grooves and sliders, the movement direction or position of the first base plate 31 and the second base plate 35 is limited, preventing the buffer assembly 3 from dislodging from the second elongated hole 11, and at the same time, a notch for installing the slider is reserved in the sliding groove, which can be closed when the slider is installed in the sliding groove.

[0038] like Figure 5As shown, each buffer assembly 3 is provided with two buffer units 36, and the two buffer units 36 are symmetrically arranged with the center line of the corresponding first elongated hole 12 in its length direction as the axis of symmetry; each buffer unit 36 ​​includes a first sleeve 311 and a second sleeve 351; the first sleeve 311 is fixed to the side of the first base plate 31 near the second base plate 35; the second sleeve 351 is fixed to the side of the second base plate 35 near the first base plate 31; a shaft core 33 is provided between the first sleeve 311 and the second sleeve 351; the two ends of the shaft core 33 are respectively movably inserted into the second sleeve 351 and the first sleeve 311; a spring 32 is sleeved on the shaft core 33, and the two ends of the spring 32 abut against the second sleeve 351 and the first sleeve 311 respectively.

[0039] In this embodiment, the first base plate 31, the second base plate 35 and the buffer unit 36 ​​are all located in the second elongated hole 11 to prevent the corresponding components from extending out of the second elongated hole 11. When the first base plate 31 and the second base plate 35 partially extend out or into the sleeve, the corresponding part of the plate can be cut.

[0040] In this embodiment, the shaft core is a telescopic rod with telescopic function, which includes multiple telescopic joints to achieve telescopic movement.

[0041] In other embodiments, the shaft core may be made of an elastic material, such as a polyurethane damper, to enable telescopic functionality.

[0042] The buffer unit 36 ​​also includes a disc spring 34, which is located in the second sleeve 351. The two ends of the disc spring 34 are in contact with the shaft core 33 and the second base plate 35, respectively.

[0043] In this embodiment, one end of the disc spring 34 is fixed to the second base plate 35, and the other end is connected to the mounting end of the telescopic rod (i.e., the shaft core 33). The spring 32 is sleeved on the telescopic rod, and the telescopic end of the telescopic rod is fixed to the first base plate 31.

[0044] The length of the second sleeve 351 is twice the height of the disc spring, and the height of the disc spring 34 is the same as the length of the first sleeve 311.

[0045] When the flat key acts on the first base plate 31, the disc spring and the spring are compressed and deformed due to the external force. Therefore, the disc spring and the spring are deformed and play a buffering role, which can reduce vibration and prevent the axial external force from acting directly on the connection between the turbine shaft and the generator shaft. Example

[0046] The adjustment method for the turbine shaft and generator shaft connection device used in pumped storage power stations, as described above, includes the following steps:

[0047] Step 1: Insert one end of the generator shaft into the sleeve, then embed each flat key into the corresponding first elongated hole and keyway, and install a buffer assembly in each second elongated hole to connect the turbine shaft and the generator shaft; both ends of the flat key contact the corresponding buffer assembly respectively;

[0048] Step 2: When the turbine unit of the pumped storage power station experiences vibration due to lifting, the reverse axial force is greater than the total weight of the rotating parts of the unit. The rotating parts of the unit are lifted to a certain height, i.e., the generator shaft is stationary, and the turbine shaft moves in the direction of the generator shaft. The bottom of the buffer assembly near the generator shaft is squeezed, and the spring on the corresponding side is in a compressed state. At this time, the second base plate is in close contact with the second side wall, the disc spring is compressed by the shaft core, and the spring sleeved around the shaft core is compressed by the combination of the first sleeve and the second sleeve. The compression process of the buffer assembly 3 reduces the impact force of the turbine shaft 2, preventing the lifting of the unit from impacting the generator part and causing damage to the generator part.

[0049] When the rotating part of the unit falls back, the buffer component on the side away from the motor shaft is in a compressed state. The compression process is the same as described above. The buffer process reduces the axial impact force, avoids damage or detachment of bolts in the traditional main shaft outer flange connection method, and eliminates safety hazards.

[0050] It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention; any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A connection device for the turbine shaft and generator shaft of a pumped storage power station, characterized in that, Includes a sleeve (13) and multiple flat keys (21), with one end of the turbine shaft (2) inserted and fixed in the sleeve (13); Multiple first elongated holes (12) are provided on the side wall of the sleeve (13). The multiple first elongated holes (12) are evenly distributed around the outer wall of the sleeve (13) in the circumferential direction. Each first elongated hole (12) is parallel to the center line of the sleeve (13). Each of the first elongated holes (12) has a second elongated hole (11) at each end; each of the first elongated holes (12) and the two second elongated holes (11) at its two ends are arranged in an I-shape, and each of the first elongated holes (12) is connected to the two second elongated holes (11) at its two ends; Each of the second elongated holes (11) is equipped with a buffer assembly (3); Multiple keyways are provided on the connecting end of the generator shaft (1), and the multiple keyways are evenly distributed around the outer wall of the turbine shaft (2) in the circumferential direction; After the turbine shaft (2) and the generator shaft (1) are connected, the connecting end of the generator shaft (1) is inserted into the sleeve (13), and each flat key (21) is embedded in the corresponding first elongated hole (12) and keyway respectively. The two ends of each flat key (21) are in contact with the corresponding buffer assembly (3); The buffer assembly (3) includes a first base plate (31), a second base plate (35), and at least one buffer unit (36). Of the two sidewalls along the length of each second elongated hole (11), the one closer to the first elongated hole (12) is designated as the first sidewall; the other is designated as the second sidewall. The first base plate (31) is parallel to and in contact with the first side wall, and the second base plate (35) is parallel to and in contact with the second side wall; The buffer unit (36) is located between the first base plate (31) and the second base plate (35), and its two ends are connected to the first base plate (31) and the second base plate (35) respectively. Each buffer component (3) is provided with two buffer units (36); Each buffer unit (36) includes a first sleeve (311) and a second sleeve (351); the first sleeve (311) is fixed to the side of the first base plate (31) near the second base plate (35); the second sleeve (351) is fixed to the side of the second base plate (35) near the first base plate (31); A shaft (33) is provided between the first sleeve (311) and the second sleeve (351); the two ends of the shaft (33) are respectively inserted into the second sleeve (351) and the first sleeve (311); A spring (32) is sleeved on the shaft core (33), and the two ends of the spring (32) are in contact with the second sleeve (351) and the first sleeve (311) respectively; the shaft core is a telescopic rod with telescopic function, and the telescopic rod includes multiple telescopic joints; The buffer unit (36) also includes a disc spring (34), which is located in the second sleeve (351). The two ends of the disc spring (34) are in contact with the shaft core (33) and the second base plate (35), respectively.

2. The turbine shaft and generator shaft connection device for a pumped storage power station according to claim 1, characterized in that, The length of the second sleeve (351) is twice the height of the disc spring (34), and the height of the disc spring (34) is the same as the length of the first sleeve (311).

3. The turbine shaft and generator shaft connection device for a pumped storage power station according to claim 2, characterized in that, The length of the first elongated hole (12) is equal to the length of the flat key (21).

4. The turbine shaft and generator shaft connection device for a pumped storage power station according to claim 3, characterized in that, The number of the first elongated hole (12), the flat key (21) and the keyway are all 6, and the number of the buffer assembly (3) and the second elongated hole (11) are all 12.

5. The turbine shaft and generator shaft connection device for a pumped storage power station according to claim 4, characterized in that, The turbine shaft (2) and the sleeve (13) are integrally formed.

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