Method for preventing outer ring piece of upper guide bearing sliding rotor of hydropower station from loosening

Abstract

The invention provides a method for preventing an outer ring piece of a sliding rotor of an upper guide bearing of a hydropower station from loosening, which comprises the following steps of: cleaning an insulating layer between an inner ring piece and the outer ring piece, and heating epoxy glass grey cloth to be softened; winding a plurality of layers of epoxy glass grey cloth on the metal surface of the outer surface of the inner ring piece to be tightly attached; winding a copper wire net outside the epoxy glass grey cloth, winding a plurality of layers of epoxy glass grey cloth on the outer layer of the copper wire net to form a new insulating layer, wrapping tightly by using a heat-shrinkable tape, heating and curing the inner ring piece, and removing the heat-shrinkable tape after cooling; and turning a new insulating layer according to the technical requirements of the inner diameter size and the assembly pre-tightening amount of the outer ring piece, uniformly heating the outer ring piece until the expansion amount meets the requirement, and thermally sleeving the outer ring piece on the inner ring piece to obtain a new sliding rotor. The problem that the upper guide bearing sliding rotor outer ring piece is loosened is solved, and long-term safe and stable operation of a hydropower station is guaranteed.

Description

Technical Field

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

[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 passing through the sliding rotor and the upper guide shoe eroding the upper guide shoe surface, an insulating separation layer is set between the inner ring and the outer ring of the sliding rotor. This layer should have sufficient strength, pre-tightening interference, reliable contact and insulation performance to ensure that the outer ring of the upper guide sliding rotor and the insulation layer will not loosen due to the unbalanced radial force of the unit operation and long-term immersion in the high-temperature turbine oil, and maintain insulation performance. For a long time, the design assembly preload experience value has been using the previous load value of 0.315~0.6mm. As the unit capacity becomes larger and larger, the outer diameter of the upper guide sliding rotor outer ring increases accordingly. The existing load does not take into account the compression of the insulating layer due to its own elasticity, and does not take into account the additional requirements for load on the large-size units and large-diameter upper guide sliding rotors of the current super-large hydropower stations, resulting in an obvious shortage of load. At the same time, the manufacturing and processing technology of the insulating layer set on the inner and outer rings has not yet formulated corresponding supporting methods and specifications in the hydropower industry, and the manufacturing methods and precision are uneven, which does not match the high-precision requirements of large-scale unit assembly. During the operation of the unit, the guide bearing and the sliding rotor outer ring generate heat due to contact and friction, causing the temperature of the lubricating oil and the upper guide sliding rotor outer ring to rise. When the expansion of the outer ring caused by the temperature increase is greater than the assembly load, the outer ring becomes loose, which can easily cause serious unit operation accidents and cause losses to the hydropower station production. Therefore, it is necessary to improve the existing design and assembly tightening experience and the manufacturing method of the insulation layer to prevent the outer ring of the guide bearing sliding rotor of the hydropower station from loosening during the long-term operation of the unit and reduce safety risks and hidden dangers. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, an embodiment of the present invention provides a method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening based on the capacitor deionization technology, which solves the problem of the outer ring of the upper guide bearing sliding rotor loosening caused by the small design tightness experience value, manufacturing technology process deviation, and thermal expansion of the oil temperature rise during the operation of the unit.

[0004] The embodiment of the present invention provides a method for preventing the outer ring of a guide bearing sliding rotor of a hydropower station from loosening, comprising the following steps:

[0005] 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 cloth until it softens and the self-contained insulation glue on the surface does not stick to your hands;

[0006] S2, evenly brushing the prepared insulating glue on the outer metal surface of the inner ring of the sliding rotor, and then winding the epoxy glass cloth on the outer metal surface of the inner ring for several layers, and evenly brushing the insulating glue on the outer side of each layer of the epoxy glass cloth during the winding process, so that the epoxy glass cloth is closely attached to the inner ring;

[0007] S3, winding a copper wire mesh on the outside of the epoxy glass blank cloth, and the copper wire mesh is glued to the outside of the epoxy glass blank cloth;

[0008] S4, wrapping several layers of epoxy glass cloth on the outer layer of the copper wire mesh, and evenly applying insulating glue on the outer side of each layer of epoxy glass cloth during the winding process, so that the epoxy glass cloth is closely attached to the outer side of the copper wire mesh to form a new insulating layer, and wrapping it tightly with a heat shrink tape, heating and curing the inner ring, and removing the heat shrink tape after cooling;

[0009] S5, turning a new insulating layer according to the technical requirements of the inner diameter size of the outer ring and the assembly preload, wherein the technical requirements include: the assembly preload of the outer ring is 0.6mm to 0.8mm, when turning the new insulating layer, ensure that the surface of the new insulating layer is smooth, and the roundness and coaxiality of the new insulating layer are controlled within 0.05mm;

[0010] S6, uniformly heat the outer ring until the expansion reaches the required amount, and then heat-sleeve it on the inner ring to obtain a new sliding rotor. Put the new sliding rotor on the machine tool to remeasure the dimensions of each part, and turn and grind the new sliding rotor according to the requirements of the drawing until the coaxiality and roundness of the inner and outer circles meet the design requirements.

[0011] In some embodiments, the epoxy glass cloth has a thickness of 0.2 mm.

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

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

[0014] In some embodiments, in step S2, the epoxy glass cloth is closely attached to the inner ring and then 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 cloth, and the upper and lower ends of the copper wire mesh are both located inside the epoxy glass blank cloth.

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

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

[0018] In some embodiments, in step S6, the step of heating the outer ring is: placing the outer ring in an electric furnace box, raising the temperature by 4 to 8°C per hour, heating time is 6 to 12 hours, the final temperature is lower than 100°C, and measuring the expansion of the outer ring every half hour until the expansion reaches the requirement of 0.6mm to 0.8mm, then stopping the heating. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0020] in:

[0021] Figure 1 It is a flow chart of a method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening based on the capacitive deionization technology in an embodiment of the present invention;

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

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

[0024] Reference numerals:

[0025] 1. Inner ring; 2. New insulation layer; 3. Outer ring; 4. Upper guide shaft. DETAILED DESCRIPTION

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

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

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

[0029] S1, disassemble the loose 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, and heat the epoxy glass cloth until it softens and the self-contained insulation glue on the surface does not stick to your hands;

[0030] S2, evenly brush the prepared insulating glue on the outer metal surface of the inner ring 1 of the sliding rotor, and then wind the epoxy glass cloth on the outer metal surface of the inner ring 1 for several layers, and evenly brush the insulating glue on the outer side of each layer of the epoxy glass cloth during the winding process, so that the epoxy glass cloth is closely attached to the inner ring 1;

[0031] S3, winding a copper wire mesh on the outside of the epoxy glass blank cloth, and the copper wire mesh is glued to the outside of the epoxy glass blank cloth;

[0032] S4, wrapping several layers of epoxy glass cloth on the outer layer of the copper wire mesh, and evenly applying insulating glue on the outer side of each layer of epoxy glass cloth during the winding process, so that the epoxy glass cloth is closely attached to the outer side of the copper wire mesh to form a new insulating layer 2, and wrapping it tightly with a heat shrink tape, heating and curing the inner ring 1, and removing the heat shrink tape after cooling;

[0033] S5, turning the new insulating layer 2 according to the technical requirements of the inner diameter size of the outer ring 3 and the assembly preload, wherein the technical requirements include: the assembly preload of the outer ring 3 is 0.6 mm to 0.8 mm, when turning the new insulating layer 2, ensure that the surface of the new insulating layer 2 is smooth, and the roundness and coaxiality of the new insulating layer 2 are controlled within 0.05 mm;

[0034] S6, heat the outer ring 3 evenly until the expansion reaches the requirement, then hot-sleeve it on the inner ring 1 to obtain a new sliding rotor, put the new sliding rotor on the machine tool to remeasure the dimensions of each part, turn and grind the new sliding rotor according to the requirements of the drawing until the coaxiality and roundness of the inner and outer circles meet the design requirements.

[0035] The embodiment of the present invention solves the problem of the upper guide bearing sliding rotor outer ring 3 being loose due to the small design tightening experience value, manufacturing technology process deviation, and thermal expansion caused by the increase of oil temperature during unit operation. The existing preparation method of the insulation layer is improved, and the quality of the insulation layer and the technical process of fine processing are improved. The problem of the sliding rotor outer ring 3 expanding due to the increase of the tile temperature and oil temperature after the unit is operated, the disappearance of the pre-tightening amount between the sliding rotor outer ring 3 and the inner ring 1 insulation layer, and the loosening of the sliding rotor outer ring 3 due to the action of inertial force are prevented, so as to ensure the long-term safe and stable operation of the hydropower station. Reduce safety risks and hidden dangers.

[0036] The method of the embodiment of the present invention is applicable to a hydro-generator set with a single unit capacity of ≤700MW.

[0037] In some embodiments, the epoxy glass cloth has a thickness of 0.2 mm.

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

[0039] It should be noted that although the epoxy glass cloth has its own insulating glue, in order to improve the bonding strength, another insulating glue is prepared.

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

[0041] In some embodiments, in step S2, the epoxy glass cloth is closely attached to the inner ring member 1 and then smoothed with an electric iron to squeeze out the air between the layers, thereby improving the bonding strength.

[0042] Furthermore, the epoxy glass fabrics do not overlap when overlapped, and the seams between the epoxy glass fabrics are less than 10 mm.

[0043] In some embodiments, the width of the copper wire mesh is smaller than the width of the epoxy glass blank cloth, and the upper and lower ends of the copper wire mesh are both located inside the epoxy glass blank cloth 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 cloth, 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 cloth, preferably 15 mm.

[0045] In some embodiments, in step S4, the inner ring 1 is heated and cured as follows: the inner ring 1 is placed in an electric furnace for preheating, raised to 60°C, kept at a constant temperature for 24 hours, then raised to 100°C, kept at a constant temperature for 2 hours, and then further raised to 135°C, kept at a constant temperature for 6 hours. The use of an electric furnace for heating makes it easier to control the temperature and makes the temperature of the inner ring 1 more uniform.

[0046] In some embodiments, in step S6, the step of heating the outer ring 3 is as follows: the outer ring 3 is placed in an electric furnace, the temperature rises by 4 to 8°C per hour, the heating time is 6 to 12 hours, the final temperature is lower than 100°C, and the expansion of the outer ring 3 is measured every half an hour until the expansion reaches the requirement of 0.6mm to 0.8mm, then the heating is stopped. It is easier to control the temperature, and it is possible to accurately determine whether the outer ring 3 meets the expansion requirement.

[0047] Further, a micrometer is used to manually measure the expansion of the outer ring 3. During the measurement process, protection is taken to avoid burns.

[0048] The present invention is further described below through specific examples.

[0049] Example 1

[0050] A method for preventing the outer ring of a guide bearing sliding rotor of a hydropower station from loosening comprises 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 enough 0.2mm thick epoxy glass cloth, curing agent, epoxy resin and special tools, heat the cut epoxy glass cloth to 50-60℃ with hot air equipment, and the control principle is based on the premise that the epoxy glass cloth is softened and the self-contained insulating glue on the surface does not stick to the hands. Use curing agent and epoxy resin to prepare insulating glue (epoxy resin glue), and the mass ratio of epoxy resin to curing agent is 100:10.

[0052] S2, evenly apply the prepared insulating glue on the outer metal surface of the inner ring 1 of the sliding rotor, and then fit and wrap the epoxy glass cloth on the outer metal surface of the inner ring 1. During the winding process, the epoxy glass cloth is promptly and evenly applied with enough insulating glue on the outside of each layer, so that the epoxy glass cloth can be bonded, tightened and fit flat. The force used when applying the insulating glue should be appropriate, and an electric iron should be used to smoothen and squeeze out the air between the layers. The epoxy glass cloth does not overlap when it is overlapped, and the seams between the epoxy glass cloths are less than 10mm.

[0053] S3, after the epoxy glass cloth is wound with 7 layers, a copper wire mesh is wound on the outside of the epoxy glass cloth. The copper wire mesh is glued to the outside of the epoxy glass cloth. The copper wire mesh is required to be straight, not open, and have a flat surface. The upper end of the copper wire mesh is about 15mm lower than the upper end of the epoxy glass cloth, and the lower end of the copper wire mesh is about 15mm higher than the lower end of the epoxy glass cloth to prevent the copper wire from being exposed.

[0054] S4, wrap several layers of epoxy glass cloth on the outer layer of the copper wire mesh. During the winding process, evenly apply insulating glue on the outside of each layer of epoxy glass cloth to make the epoxy glass cloth fit tightly on the outside of the copper wire mesh. Wrap the epoxy glass cloth to 20 layers (plus the 7 layers in step S3, a total of 20 layers) to form a new insulating layer 2, wrap it tightly with a heat shrink tape, heat and cure the inner ring 1, and remove the heat shrink tape after cooling. Among them, the steps of heating and curing the inner ring 1 are: put the inner ring 1 into the electric furnace box for preheating, raise the temperature to 60°C, keep the temperature constant for 24 hours, then raise the temperature to 100°C, keep the temperature constant for 2 hours, continue to raise the temperature to 135°C, keep the temperature constant for 6 hours, and then remove the heat shrink tape after cooling to room temperature with the furnace.

[0055] S5, turning the new insulating layer 2 according to the technical requirements of the inner diameter size of the outer ring 3 and the assembly preload, wherein the assembly preload of the outer ring 3 is 0.6 mm to 0.8 mm. When turning the new insulating layer 2, ensure that the surface of the new insulating layer 2 is smooth, and the roundness and coaxiality of the new insulating layer 2 are controlled within 0.05 mm;

[0056] S6, heat the outer ring 3 evenly until the expansion reaches the requirement of 0.6mm~0.8mm, then hot-sleeve it on the inner ring 1 to obtain a new sliding rotor, put the new sliding rotor on the machine tool to remeasure the dimensions of each part, turn and grind the new sliding rotor according to the requirements of the drawing until the coaxiality and roundness of the inner and outer circles meet the design requirements.

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

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In the present invention, the term "some embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments and features of the different embodiments described in this specification without contradiction.

[0060] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preventing the outer ring of the guide bearing sliding rotor of a hydropower station from loosening, characterized in that: The steps include: S1, disassemble the loose sliding rotor to obtain an inner ring and an outer ring, clean the original insulating layer between the inner ring and the outer ring, and heat the epoxy glass blank cloth until it softens and the self-contained insulating glue on the surface does not stick to the hands; S2, evenly brushing the prepared insulating glue on the outer metal surface of the inner ring of the sliding rotor, and then winding the epoxy glass cloth on the outer metal surface of the inner ring for several layers, and evenly brushing the insulating glue on the outer side of each layer of the epoxy glass cloth during the winding process, so that the epoxy glass cloth is closely attached to the inner ring; S3, winding a copper wire mesh on the outside of the epoxy glass blank cloth, and the copper wire mesh is glued to the outside of the epoxy glass blank cloth by glue; S4, winding several layers of the epoxy glass cloth on the outer layer of the copper wire mesh, and evenly applying the insulating glue on the outer side of each layer of the epoxy glass cloth during the winding process, so that the epoxy glass cloth is closely attached to the outer side of the copper wire mesh to form a new insulating layer, and wrapping it tightly with a heat shrink tape, heating and curing the inner ring, and removing the heat shrink tape after cooling; S5, turning the new insulating layer according to the technical requirements of the inner diameter size of the outer ring and the assembly preload, wherein the technical requirements include: the assembly preload of the outer ring is 0.6 mm to 0.8 mm, and when turning the new insulating layer, ensure that the surface of the new insulating layer is smooth, and the roundness and coaxiality of the new insulating layer are controlled within 0.05 mm; S6, uniformly heat the outer ring until the expansion reaches the required amount, and then hot-sleeve it on the inner ring to obtain a new sliding rotor. Put the new sliding rotor on the machine tool to remeasure the dimensions of each part, and turn and grind the new sliding rotor according to the requirements of the drawing until the coaxiality and roundness of the inner and outer circles meet the design requirements.

2. The method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening according to claim 1 is characterized in that: The thickness of the epoxy glass cloth is 0.2 mm.

3. The method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening according to claim 1, characterized in that: The insulating adhesive is prepared by using epoxy resin and curing agent, and the mass ratio of epoxy resin to curing agent is 100:

10.

4. The method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening according to claim 1, characterized in that: In step S1, the epoxy glass cloth is heated to 50-60° C. by hot air heating.

5. The method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening according to claim 1, characterized in that: In step S2, the epoxy glass cloth is closely attached to the inner ring and then smoothed with an electric iron to squeeze out the air between the layers.

6. The method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening according to claim 1, characterized in that: The width of the copper wire mesh is smaller than the width of the epoxy glass blank cloth, and the upper and lower ends of the copper wire mesh are both located inside the epoxy glass blank cloth.

7. The method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening according to claim 6, characterized in that: The upper end of the copper wire mesh is 10-20 mm lower than the upper end of the epoxy glass blank cloth, and the lower end of the copper wire mesh is 10-20 mm higher than the lower end of the epoxy glass blank cloth.

8. The method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening according to claim 1, characterized in that: In step S4, the inner ring is heated and cured as follows: the inner ring is placed in an electric furnace for preheating, the temperature is raised to 60°C, and the temperature is kept constant for 24 hours, then the temperature is raised to 100°C, and the temperature is kept constant for 2 hours, and the temperature is further raised to 135°C and the temperature is kept constant for 6 hours.

9. The method for preventing the outer ring of the upper guide bearing sliding rotor of a hydropower station from loosening according to claim 7, characterized in that: In step S6, the step of heating the outer ring is as follows: placing the outer ring in an electric furnace, raising the temperature by 4 to 8°C per hour, heating for 6 to 12 hours, and finally the temperature being lower than 100°C. The expansion of the outer ring is measured every half hour, and heating is stopped when the expansion reaches the requirement of 0.6mm to 0.8mm.

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