Method for preventing loosening of outer ring of hydroelectric power station upper guide bearing sliding rotor

Abstract

This invention proposes a method to prevent loosening of the outer ring component of the sliding rotor of the upper guide bearing in a hydropower station, comprising the following steps: cleaning the insulation layer between the inner and outer ring components; heating epoxy glass cloth until softened; wrapping several layers of epoxy glass cloth tightly around the outer metal surface of the inner ring component; wrapping copper wire mesh around the outside of the epoxy glass cloth, and then wrapping several more layers of epoxy glass cloth around the outer layer of the copper wire mesh to form a new insulation layer; using heat-shrinkable tape for tight wrapping; heating and curing the inner ring component; removing the heat-shrinkable tape after cooling; machining the new insulation layer according to the inner diameter and assembly preload requirements of the outer ring component; heating the outer ring component uniformly until the required expansion is achieved, and then heat-fitting it onto the inner ring component to obtain a new sliding rotor. This invention solves the problem of loosening of the outer ring component of the upper guide bearing sliding rotor, ensuring the long-term safe and stable operation of the hydropower station.

Description

Technical Field

[0001] This invention relates to the field of bearing technology, and in particular to a method for preventing loosening of the outer ring of the sliding rotor of the upper guide bearing in a hydropower station based on capacitive deionization technology. Background Technology

[0002] Due to the inherent structural characteristics and performance requirements of the upper guide bearing sliding rotor, in order to prevent the shaft current of the unit from eroding the surface of the upper guide bearing through the sliding rotor and the upper guide bearing, an insulating separation layer is set between the inner and outer ring parts of the sliding rotor. This layer should have sufficient strength, preload interference, reliable contact and insulation performance to ensure that the outer ring part of the upper guide sliding rotor and the insulating layer do not loosen due to the radial force of the unit's unbalanced operation and long-term immersion in high-temperature turbine oil, and maintain the insulation performance. For a long time, the design and assembly pre-tightening amount has been based on the old values ​​of 0.315-0.6mm. As the unit capacity increases, the outer diameter of the outer ring of the upper guide rotor also increases. The existing tightness does not take into account the compression caused by the elasticity of the insulation layer, nor does it take into account the additional tightness requirements of the large-size units and large-diameter upper guide rotors of current ultra-large hydropower stations. This has resulted in a significant shortage of tightness. At the same time, the manufacturing and processing technology of the insulation layer of the inner and outer ring components is inconsistent due to the lack of corresponding supporting methods and standards in the hydropower industry. This is not compatible with the high precision requirements of large unit assembly. During the operation of the unit, the contact friction between the guide shaft bearing and the outer ring of the upper guide rotor generates heat, causing the temperature of the lubricating oil and the outer ring of the upper guide rotor to rise. When the expansion of the outer ring caused by the temperature rise exceeds the assembly tightness, the outer ring may loosen, which can easily lead to serious unit operation accidents and losses to hydropower station production. Therefore, it is necessary to improve the existing design assembly tightness experience values ​​and insulation layer manufacturing methods to prevent loosening accidents of the outer ring of the sliding rotor of the upper guide bearing in hydropower stations during long-term operation of the unit, and reduce safety risks and hidden dangers. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention provide a method for preventing loosening of the outer ring of the upper guide bearing sliding rotor in hydropower stations based on capacitive deionization technology. This method solves the problem of loosening of the outer ring of the upper guide bearing sliding rotor caused by factors such as insufficient design tightness, manufacturing process deviations, and thermal expansion due to rising oil temperature during unit operation.

[0004] This invention provides a method for preventing loosening of the outer ring of the sliding rotor of the upper guide bearing in a hydropower station, comprising the following steps:

[0005] S1. Disassemble the loose sliding rotor to obtain the inner ring and outer ring. Clean the original insulation layer between the inner ring and outer ring. Heat the epoxy glass blank until it softens and the self-insulating adhesive on the surface is no longer sticky.

[0006] S2, apply the prepared insulating adhesive evenly to the outer metal surface of the inner ring of the sliding rotor, and then wrap several layers of epoxy glass cloth around the outer metal surface of the inner ring. During the wrapping process, apply insulating adhesive evenly to the outside of each layer of epoxy glass cloth so that the epoxy glass cloth adheres tightly to the inner ring.

[0007] S3, copper wire mesh is wrapped around the outside of the epoxy glass blank, and the copper wire mesh is glued to the outside of the epoxy glass blank.

[0008] S4. Several layers of epoxy glass cloth are wrapped around the outer layer of the copper wire mesh. During the wrapping process, insulating adhesive is evenly applied to the outside of each layer of epoxy glass cloth so that the epoxy glass cloth is tightly attached to the outside of the copper wire mesh to form a new insulating layer. Heat shrink tape is used to wrap it tightly, the inner ring is heated and cured, and the heat shrink tape is removed after cooling.

[0009] S5. According to the technical requirements of the inner diameter of the outer ring and the assembly preload, the new insulation layer is machined. The technical requirements include: the assembly preload of the outer ring is 0.6mm to 0.8mm; when machining the new insulation layer, ensure that the surface of the new insulation layer is smooth; and control the roundness and coaxiality of the new insulation layer within 0.05mm.

[0010] S6. After heating the outer ring component evenly until the expansion reaches the required amount, heat-fit it onto the inner ring component to obtain a new sliding rotor. Then, re-measure the dimensions of each part of the new sliding rotor on the machine tool and turn and grind the new sliding rotor according to the drawing requirements until its inner and outer circles coaxiality and roundness meet the design requirements.

[0011] In some embodiments, the thickness of the epoxy glass preform is 0.2 mm.

[0012] In some embodiments, the insulating adhesive is formulated with epoxy resin and a curing agent, wherein the mass ratio of epoxy resin to curing agent is 100:10.

[0013] In some embodiments, in step S1, the epoxy glass blank is heated to 50-60°C by hot air heating.

[0014] In some embodiments, in step S2, after the epoxy glass blank is tightly bonded to the inner ring, it is smoothed with an electric iron to squeeze out the air between the layers.

[0015] In some embodiments, the width of the copper wire mesh is smaller than the width of the epoxy glass blank, and both the upper and lower ends of the copper wire mesh are located within the epoxy glass blank.

[0016] In some embodiments, the upper end of the copper wire mesh is 10-20mm lower than the upper end of the epoxy glass blank, and the lower end of the copper wire mesh is 10-20mm higher than the lower end of the epoxy glass blank.

[0017] In some embodiments, the step of heating and curing the inner ring in step S4 is as follows: the inner ring is placed in an electric furnace for preheating, the temperature is raised to 60°C and kept constant for 24 hours, then the temperature is raised to 100°C and kept constant for 2 hours, and then the temperature is raised to 135°C and kept constant for 6 hours.

[0018] In some embodiments, the heating step of the outer ring component in step S6 is as follows: the outer ring component is placed in an electric furnace box, the temperature is increased by 4 to 8°C per hour, the heating time is 6 to 12 hours, the final temperature is below 100°C, the expansion of the outer ring component is measured every half hour, and heating is stopped when the expansion reaches the requirement of 0.6 mm to 0.8 mm. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings.

[0020] in:

[0021] Figure 1 This is a flowchart of a method for preventing loosening of the outer ring of the sliding rotor of a hydropower station based on capacitive deionization technology, as described in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the assembly between the insulating layer and the inner ring and outer ring components in an embodiment of the present invention;

[0023] Figure 3 for Figure 2 A schematic diagram of the assembly of the insulating layer and the inner ring component;

[0024] Figure label:

[0025] 1. Inner ring component; 2. New insulation layer; 3. Outer ring component; 4. Upper guide shaft. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The following describes a method for preventing loosening of the outer ring of the sliding rotor of the upper guide bearing in a hydropower station based on capacitive deionization technology, according to an embodiment of the present invention, with reference to the accompanying drawings.

[0028] like Figure 1-3 As shown in the figure, this invention proposes a method for preventing loosening of the outer ring of the sliding rotor of the upper guide bearing in a hydropower station, comprising the following steps:

[0029] S1, disassemble the loose sliding rotor to obtain inner ring 1 and outer ring 3, clean the original insulation layer between inner ring 1 and outer ring 3, and heat the epoxy glass blank until it softens and the self-insulating adhesive on the surface is no longer sticky.

[0030] S2, the prepared insulating adhesive is evenly applied to the outer metal surface of the inner ring 1 of the sliding rotor, and then several layers of epoxy glass cloth are wrapped around the outer metal surface of the inner ring 1. During the wrapping process, insulating adhesive is evenly applied to the outside of each layer of epoxy glass cloth so that the epoxy glass cloth is tightly attached to the inner ring 1.

[0031] S3, copper wire mesh is wrapped around the outside of the epoxy glass blank, and the copper wire mesh is glued to the outside of the epoxy glass blank.

[0032] S4. Several layers of epoxy glass cloth are wrapped around the outer layer of the copper wire mesh. During the wrapping process, insulating adhesive is evenly applied to the outside of each layer of epoxy glass cloth so that the epoxy glass cloth is tightly attached to the outside of the copper wire mesh to form a new insulating layer 2. Heat shrink tape is used to wrap it tightly, and the inner ring 1 is heated and cured. After cooling, the heat shrink tape is removed.

[0033] S5. According to the technical requirements of the inner diameter of the outer ring 3 and the assembly preload, the new insulation layer 2 is machined. The technical requirements include: the assembly preload of the outer ring 3 is 0.6mm to 0.8mm, and when machining the new insulation layer 2, the surface of the new insulation layer 2 is kept smooth, and the roundness and coaxiality of the new insulation layer 2 are controlled within 0.05mm.

[0034] S6. Heat the outer ring 3 evenly until the expansion reaches the required amount, then heat-fit it onto the inner ring 1 to obtain a new sliding rotor. Place the new sliding rotor on a machine tool to re-measure the dimensions of each part, and turn and grind the new sliding rotor according to the drawing requirements until its inner and outer circles coaxiality and roundness meet the design requirements.

[0035] This invention, through the aforementioned method, solves the problem of loosening of the outer ring 3 of the upper guide bearing sliding rotor caused by factors such as insufficient design tightness, manufacturing process deviations, and thermal expansion due to rising oil temperature during unit operation. It improves existing insulation layer preparation methods, enhancing insulation layer quality and precision machining techniques. This prevents the outer ring 3 from expanding due to increased bearing and oil temperatures after unit operation, the loss of pre-tightness between the outer ring 3 and the inner ring 1 insulation layer, and loosening of the outer ring 3 under inertial forces, ensuring the long-term safe and stable operation of the hydropower station and reducing safety risks and hidden dangers.

[0036] The method of this invention is applicable to hydro-generator units with a single unit capacity of ≤700MW or less.

[0037] In some embodiments, the thickness of the epoxy glass preform is 0.2 mm.

[0038] In some embodiments, the insulating adhesive is formulated with epoxy resin and a curing agent in a mass ratio of 100:10. This ratio is determined based on the chemical properties and reaction rate of the resin and the curing agent to ensure that the resin and the curing agent can react fully to form a strong bond.

[0039] It should be noted that although epoxy glass cloth has its own insulating adhesive, an additional insulating adhesive is prepared in order to improve the adhesion.

[0040] In some embodiments, in step S1, the epoxy glass blank is heated to 50-60°C by hot air heating. The epoxy glass blank is heated using a hot air device.

[0041] In some embodiments, in step S2, after the epoxy glass blank is tightly bonded to the inner ring 1, it is smoothed with an electric iron to squeeze out the air between the layers, which can improve the bonding strength.

[0042] Furthermore, the epoxy glass fabric does not overlap when it is lapped, and the seam between the epoxy glass fabrics is less than 10mm.

[0043] In some embodiments, the width of the copper wire mesh is smaller than the width of the epoxy glass blank, and both the upper and lower ends of the copper wire mesh are located inside the epoxy glass blank to prevent the copper wires from being exposed.

[0044] In some embodiments, the upper end of the copper wire mesh is 10-20 mm lower than the upper end of the epoxy glass blank, preferably 15 mm, and the lower end of the copper wire mesh is 10-20 mm higher than the lower end of the epoxy glass blank, preferably 15 mm.

[0045] In some embodiments, the step S4, the heating and curing step of the inner ring 1, involves placing the inner ring 1 in an electric furnace for preheating, raising the temperature to 60°C, maintaining the temperature for 24 hours, then raising the temperature to 100°C, maintaining the temperature for 2 hours, and then further raising the temperature to 135°C, maintaining the temperature for 6 hours. Using an electric furnace for heating makes temperature control easier and results in a more uniform temperature for the inner ring 1.

[0046] In some embodiments, the heating step S6 of the outer ring 3 involves placing the outer ring 3 into an electric furnace chamber, increasing the temperature by 4–8°C per hour, heating for 6–12 hours, and finally reducing the temperature to below 100°C. The expansion of the outer ring 3 is measured every half hour until the expansion reaches the required 0.6 mm–0.8 mm, at which point heating is stopped. This method allows for easier temperature control and accurate determination of whether the outer ring 3 has reached the required expansion.

[0047] Furthermore, the expansion of the outer ring 3 was measured manually using a micrometer. Protective measures were taken during the measurement process to avoid burns.

[0048] The present invention will be further illustrated by specific embodiments below.

[0049] Example 1

[0050] A method for preventing loosening of the outer ring of the sliding rotor of a guide bearing in a hydropower station includes the following steps:

[0051] S1. Remove the loose sliding rotor from the upper guide shaft 4 and disassemble the sliding rotor to obtain the inner ring 1 and the outer ring 3. Clean the original insulation layer between the inner ring 1 and the outer ring 3. Prepare sufficient 0.2mm thick epoxy glass blank, curing agent, epoxy resin, and special tools. Heat the cut epoxy glass blank to 50-60℃ using a hot air device, ensuring that the epoxy glass blank softens and the self-insulating adhesive on the surface is no longer sticky. Prepare an insulating adhesive (epoxy resin adhesive) using the curing agent and epoxy resin, with a mass ratio of epoxy resin to curing agent of 100:10.

[0052] S2. Apply the prepared insulating adhesive evenly to the outer metal surface of the inner ring 1 of the sliding rotor. Then, adhere and wrap the epoxy glass fiber cloth around the outer metal surface of the inner ring 1. During the wrapping process, apply sufficient insulating adhesive evenly to the outside of each layer of the epoxy glass fiber cloth to ensure it is firmly bonded and flat. Apply appropriate pressure when applying the insulating adhesive and smooth it with an electric iron to squeeze out any air between the layers. The epoxy glass fiber cloth should not overlap, and the seam between the epoxy glass fiber cloths should be less than 10mm.

[0053] S3. After wrapping 7 layers of epoxy glass fabric, wrap copper wire mesh around the outside of the epoxy glass fabric. The copper wire mesh is glued to the outside of the epoxy glass fabric. It is required that the copper wire mesh is not crooked, has no openings, and has a flat surface. The upper end of the copper wire mesh is about 15mm lower than the upper end of the epoxy glass fabric, and the lower end of the copper wire mesh is about 15mm higher than the lower end of the epoxy glass fabric to prevent the copper wires from being exposed.

[0054] S4. Several layers of epoxy glass preform cloth are then wrapped around the outer layer of the copper wire mesh. During the wrapping process, insulating adhesive is evenly applied to the outside of each layer of epoxy glass preform cloth to ensure that the epoxy glass preform cloth adheres tightly to the outside of the copper wire mesh. The epoxy glass preform cloth is wrapped up to 20 layers (plus the 7 layers in step S3, for a total of 20 layers), forming a new insulating layer 2. This is then tightly wrapped with heat shrink tape. The inner ring 1 is then heated and cured, and the heat shrink tape is removed after cooling. The heating and curing steps for the inner ring 1 are as follows: the inner ring 1 is placed in an electric furnace for preheating, raised to 60°C, and held at that temperature for 24 hours. Then, the temperature is raised to 100°C and held at that temperature for 2 hours. The temperature is then raised to 135°C and held at that temperature for 6 hours. Finally, the inner ring 1 is cooled to room temperature in the furnace, and the heat shrink tape is removed.

[0055] S5. According to the technical requirements of the inner diameter of the outer ring 3 and the assembly preload, the new insulation layer 2 is machined. The assembly preload of the outer ring 3 is 0.6mm to 0.8mm. When machining the new insulation layer 2, ensure that the surface of the new insulation layer 2 is smooth and that the roundness and coaxiality of the new insulation layer 2 are controlled within 0.05mm.

[0056] S6. After heating the outer ring 3 evenly until the expansion reaches the required 0.6mm~0.8mm, heat it onto the inner ring 1 to obtain a new sliding rotor. Then, re-measure the dimensions of each part of the new sliding rotor on the machine tool and turn and grind the new sliding rotor according to the drawing requirements until its inner and outer circles coaxiality and roundness meet the design requirements.

[0057] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0058] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] In this invention, the term "some embodiments," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments. Moreover, those skilled in the art can combine and integrate the different embodiments and features described in this specification without contradiction.

[0060] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preventing loosening of the outer ring of the sliding rotor of a guide bearing in a hydropower station, characterized in that, Includes the following steps: S1, disassemble the loose sliding rotor to obtain the inner ring and the outer ring, clean the original insulation layer between the inner ring and the outer ring, and heat the epoxy glass blank until it softens and the self-insulating adhesive on the surface is no longer sticky. S2, the prepared insulating adhesive is evenly applied to the outer metal surface of the inner ring of the sliding rotor, and then the epoxy glass blank is wound several layers on the outer metal surface of the inner ring. During the winding process, the insulating adhesive is evenly applied to the outside of each layer of the epoxy glass blank so that the epoxy glass blank is tightly attached to the inner ring. S3, a copper wire mesh is wound around the outside of the epoxy glass blank, and the copper wire mesh is glued to the outside of the epoxy glass blank; S4, several layers of epoxy glass blank are wound around the outer layer of the copper wire mesh. During the winding process, the insulating adhesive is evenly applied to the outside of each layer of the epoxy glass blank, so that the epoxy glass blank is tightly attached to the outside of the copper wire mesh to form a new insulating layer. Heat shrink tape is used to wrap it tightly, the inner ring is heated and cured, and the heat shrink tape is removed after cooling. S5. The new insulating layer is machined according to the technical requirements of the inner diameter of the outer ring and the assembly preload. The technical requirements include: the assembly preload of the outer ring is 0.6mm to 0.8mm; when machining the new insulating layer, the surface of the new insulating layer is made smooth; and the roundness and coaxiality of the new insulating layer are controlled within 0.05mm. S6. Heat the outer ring part evenly until the expansion reaches the required amount, and then heat-fit it onto the inner ring part to obtain a new sliding rotor. Place the new sliding rotor on a machine tool to re-measure the dimensions of each part, and turn and grind the new sliding rotor according to the drawing requirements until its inner and outer circles coaxiality and roundness meet the design requirements. In step S2, after the epoxy glass blank is tightly bonded to the inner ring, it is smoothed with an electric iron to squeeze out the air between the layers. In step S6, the heating step of the outer ring component is as follows: the outer ring component is placed in the electric furnace box, the temperature is increased by 4~8°C per hour, the heating time is 6~12 hours, the final temperature is below 100°C, the expansion of the outer ring component is measured every half hour, and the expansion reaches the requirement of 0.6mm~0.8mm before being heat-fitted onto the inner ring component.

2. The method of preventing loosening of the upper guide bearing runner outer ring of a hydroelectric power station according to claim 1, characterized in that, The thickness of the epoxy glass blank is 0.2 mm.

3. The method of preventing loosening of the upper guide bearing runner outer ring of a hydroelectric power station as claimed in claim 1, wherein, The insulating adhesive is formulated with epoxy resin and a curing agent, with a mass ratio of epoxy resin to curing agent of 100:

10.

4. The method of preventing loosening of the upper guide bearing runner outer ring of a hydroelectric power station as claimed in claim 1, wherein, In step S1, the epoxy glass blank is heated to 50-60°C by hot air heating.

5. The method of preventing loosening of the upper guide bearing runner outer ring of a hydroelectric power station as claimed in claim 1, wherein, The width of the copper wire mesh is smaller than the width of the epoxy glass blank, and both the upper and lower ends of the copper wire mesh are located within the epoxy glass blank.

6. The method of preventing loosening of the upper guide bearing runner outer ring of a hydroelectric power station as claimed in claim 5, wherein The upper end of the copper wire mesh is 10-20mm lower than the upper end of the epoxy glass blank, and the lower end of the copper wire mesh is 10-20mm higher than the lower end of the epoxy glass blank.

7. The method of preventing loosening of the upper guide bearing runner outer ring of a hydroelectric power station as claimed in claim 1, wherein In step S4, the heating and curing step of the inner ring is as follows: the inner ring is placed in an electric furnace for preheating, the temperature is raised to 60°C and kept constant for 24 hours, then the temperature is raised to 100°C and kept constant for 2 hours, and then the temperature is raised to 135°C and kept constant for 6 hours.

Images