Manufacturing method of dynamometer for testing axial force of gas turbine

Abstract

The invention discloses a manufacturing method of a dynamometer for testing axial force of a gas turbine, and belongs to the technical field of gas turbines. The manufacturing method solves the technical problems that an existing manufacturing method of the dynamometer for testing the axial force of the gas turbine is large in number of operation steps, complex in process, long in preparation period and low in efficiency. Comprising the following steps: polishing and cleaning the surface of the spring ring; selecting the strain gauges in accordance with a preset resistance value range; selecting a strain gauge according with a preset grid length value range of the sensitive grid, wherein the preset grid length value range of the sensitive grid of the strain gauge is r / 5 to r / 10; the surface of a non-patch groove of the spring ring is coated with a cloth piece after being coated with glue, and the surface of a patch groove of the spring ring is coated with glue; after the strain gauges are fixed in the patch grooves of the spring rings, the overall structure is sequentially subjected to heating, constant temperature maintaining and cooling curing; the surface of the strain gauge is wrapped with cloth; wiring and wiring are carried out on the fixed strain gauges; and the strain gauge is connected with an outer lead. Operation is simple, and universality is high. The method is used for manufacturing the gas turbine dynamometer.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a dynamometer for testing the axial force of a gas turbine, and belongs to the technical field of gas turbines. Background Art

[0002] The axial force of a gas turbine is the result of the combined effects of airflow, rotating components, and internal pressure distribution. If the axial force exceeds the design range, it will overload the bearings and shafting, which may lead to premature failure or damage of the components. It is very difficult to determine the axial force by theoretical calculation. The axial force determined by simulation usually deviates greatly from the actual working conditions. Therefore, it is often tested to verify whether the axial force meets the design specifications and avoid potential mechanical failures. Test data helps to optimize the structural design of the gas turbine, such as adjusting the blade shape, flow configuration, and sealing structure to ensure axial force balance. In the long-term operation of the gas turbine, the axial force may change due to material aging or component wear. Regular testing can monitor its changing trend and detect potential problems in time. The bearing capacity can be checked and optimized to extend the service life of the equipment. The axial force test of the gas turbine is not only a necessary means to ensure the safe operation of the equipment, but also an important tool for optimizing the design and improving performance. The results directly affect the operating efficiency, reliability, and life of the equipment, and are of great significance to the overall engineering of the gas turbine. Strain gauges are often pasted on bearing seats or other load-bearing components to measure the strain value of the load-bearing components, and the axial force is measured by calibrating the strain value and the axial force.

[0003] The existing method for manufacturing a dynamometer for testing the axial force of a gas turbine has the technical problems of long preparation period and low efficiency due to the large number of operation steps and complicated process. Summary of the invention

[0004] The present invention aims to solve the technical problems that the existing method for manufacturing a dynamometer for testing the axial force of a gas turbine has many operating steps, a complicated process, a long preparation period and low efficiency, and further provides a method for manufacturing a dynamometer for testing the axial force of a gas turbine.

[0005] The technical solution of the present invention is a method for manufacturing a dynamometer for testing the axial force of a gas turbine, comprising the following steps:

[0006] S1. Grind and clean the surface of the spring ring;

[0007] S2, selecting a strain gauge that meets the predetermined resistance value range;

[0008] S3, selecting a strain gauge that meets the predetermined grid length value range of the sensitive grid, the inner ring radius size of the spring ring is r, and the predetermined grid length value range of the sensitive grid of the strain gauge is r / 5 to r / 10;

[0009] S4. The non-patch groove surface of the spring ring is coated with glue and then wrapped with a cloth sheet, and the patch groove surface of the spring ring is coated with glue;

[0010] S5. After the strain gauge is fixed to the patch groove of the spring ring, the overall structure is heated up, maintained at a constant temperature, and cooled down for curing in sequence;

[0011] S6, the surface of the strain gauge is wrapped with cloth;

[0012] S7. Conduct wiring and connection of the fixed strain gauges;

[0013] S8. Connect the strain gauge to the external lead wire.

[0014] As another improvement of the present invention, step S1 includes the following sub-steps:

[0015] S11. Grind the surface of the spring ring with fine sandpaper;

[0016] S12. Use ethanol or acetone to remove dust and oil from the surface of the spring ring.

[0017] As another improvement of the present invention, step S2 includes the following sub-steps:

[0018] S21. Select the strain gauge with complete sensitive grid wire;

[0019] S22. Select a strain gauge whose resistance deviation is within the allowable range.

[0020] As another improvement of the present invention, the strain gauge is a foil strain gauge, the base material of the strain gauge is polyimide, and the material of the sensitive grid of the strain gauge is kama alloy.

[0021] As another improvement of the present invention, step S4 includes the following sub-steps:

[0022] S41. Apply the first adhesive layer evenly on the surface of the non-patch groove and the patch groove and place it in a dry environment for 20 minutes;

[0023] S42, evenly applying a second adhesive layer on the surface of the first adhesive layer in the patch groove;

[0024] S43, wrapping the cloth piece on the non-patch groove surface.

[0025] As another improvement of the present invention, step S5 includes the following sub-steps:

[0026] S51, strain gauge is placed in the middle of the patch groove of the spring ring;

[0027] S52, fixing the strain gauge and the plastic film, the silicone rubber pad and the steel sheet arranged in sequence on the upper surface of the strain gauge by a fixture;

[0028] S53, placing the entire structure in S52 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour;

[0029] S54, heating the whole structure in S53 to 150°C and maintaining the temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

[0030] As another improvement of the present invention, step S6 includes the following sub-steps:

[0031] S61. Confirm that the resistance deviation of the strain gauge is within the allowable range;

[0032] S62. Remove the fixture fixed on the strain gauge as well as the plastic film, silicone rubber pad and steel sheet;

[0033] S63. After applying a layer of glue evenly on the upper surface of the strain gauge, wrap the cloth piece around the surface of the patch groove;

[0034] S64, placing the entire structure in S63 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour;

[0035] S65, heating the whole structure in S64 to 150°C and maintaining the constant temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

[0036] As another improvement of the present invention, step S7 includes the following sub-steps:

[0037] S71, divide the fixed strain gauges into two groups, and each group of strain gauges is connected in series;

[0038] S72. When wiring, the leads of the strain gauges should be laid flat, and no overlap is allowed. After the wiring is completed, use a spot welder to weld the joints between the two strain gauges;

[0039] S73, placing the entire structure in S72 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour;

[0040] S74, heating the whole structure in S74 to 150°C and maintaining the constant temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

[0041] As another improvement of the present invention, the external lead wire in step S8 uses a 6-core wire. After the strain gauge is connected to the external lead wire, the joints are welded by a spot welding machine.

[0042] As another improvement of the present invention, the strain gauge includes a working gauge and a temperature compensation gauge, and the sensitive grid of the working gauge and the sensitive grid of the temperature compensation gauge are arranged vertically.

[0043] Beneficial effects of the present invention:

[0044] 1. The method of the present invention is simple, easy to implement, highly operable, and can be used according to the working conditions of different gas turbines or aircraft engines. The present invention has stable performance, high measurement accuracy, wide applicability, simplified process flow, and saves the cost and time of the dynamometer used for the axial force test of the gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the main view of the spring ring.

[0046] Figure 2 Schematic diagram of the side view of the spring ring.

[0047] Figure 3 This is a schematic diagram of the lead wiring of the strain gauge.

[0048] Figure 4 This is a schematic diagram of the lead wiring of the strain gauge.

[0049] Figure 5 This is a schematic diagram of the main view of the spring ring strain gauge.

[0050] Figure 6 It is a schematic diagram of the cross section of the spring ring strain gauge.

[0051] Figure 7 This is the first schematic diagram of the fabric pasting.

[0052] Figure 8 This is the second schematic diagram of the fabric pasting.

[0053] Fig. 9 This is the circuit diagram of the working chip and temperature compensation chip layout. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the examples of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0055] Specific implementation method 1: Combination Figures 1 to 9 This embodiment is described. This embodiment is a method for manufacturing a dynamometer for testing the axial force of a gas turbine, which comprises the following steps:

[0056] S1. Grind and clean the surface of the spring ring 1; used to improve the surface flatness of the spring ring 1 to ensure the quality of subsequent bonding operations; remove the surface oxide layer or dirt to enhance the adhesion performance of the adhesive; remove the dust and oil remaining on the surface after the grinding process is completed;

[0057] S2, selecting a strain gauge 4 that meets a predetermined resistance value range;

[0058] S3, selecting a strain gauge 4 that meets the predetermined range of the sensitive grid length value, the inner ring radius of the spring ring 1 is r, and the predetermined range of the sensitive grid length value of the strain gauge 4 is r / 5 to r / 10;

[0059] S4, the surface of the non-patch groove 5 of the spring ring 1 is coated with glue and then wrapped with a cloth piece, and the surface of the patch groove 3 of the spring ring 1 is coated with glue;

[0060] S5, after the strain gauge 4 is fixed at the patch groove 3 of the spring ring 1, the whole structure is heated up, maintained at a constant temperature, and cooled down for curing in sequence;

[0061] S6, the surface of strain gauge 4 is wrapped with cloth;

[0062] S7, routing and wiring the lead wires 6 of the fixed strain gauge 4;

[0063] S8. Connect the strain gauge 4 to the external lead.

[0064] The size of the spring ring should be selected according to the size of the bearing where it is installed. The outer diameter of the spring ring should not be larger than the outer diameter of the outer ring of the bearing, and the inner diameter of the spring ring should not be smaller than the inner diameter of the outer ring of the bearing. The outer diameter of the spring ring used in the present invention is φ233.7mm, and the inner diameter is Φ216mm. An anti-rotation pin hole is provided on the upper part of the spring ring to prevent the spring ring from being displaced due to vibration, friction, etc. during use, resulting in damage to the spring ring; a boss 2 is provided on the front of the spring ring, a total of 9 locations, and the thickness of the boss 2 is generally 1.5mm-2.0mm. In the side view of the spring ring, Figure 2 The plane where the left end of the middle boss is located and the plane where the right end of the boss is located have extremely high processing flatness requirements. The flatness is generally not allowed to be greater than 0.02mm, and the parallelism between the two planes is also not allowed to be greater than 0.02mm. Excessive parallelism and flatness will cause uneven force on the spring ring when it is subjected to axial force, and the deformation of the spring ring will be inconsistent, which will directly affect the accuracy of the dynamometer. The boss of the spring ring will fit with the outer ring of the bearing during use. The boss of the spring ring needs to be nitrided to improve the surface hardness, wear resistance, and corrosion resistance, and improve the fatigue life of the spring ring under alternating loads. The thickness of the nitriding layer is most suitable to be 0.3mm-0.5mm. After nitriding treatment, the surface hardness should be greater than 600HV, and the hardness of the center should be 300HV-369HV. After the nitriding treatment is completed, the spring ring needs to be chemically oxidized with oil immersion to further improve the corrosion resistance, fatigue resistance and high temperature oxidation resistance of the spring ring, and reduce friction and wear. There are spring ring grooves adjacent to the boss 2, also 9 in number, of which 3 evenly spaced ones are non-patch grooves 5, and the remaining 6 are patch grooves 4;

[0065] There are 6 strain gauges in total, and the strain gauges need to be selected according to the working environment where the dynamometer is installed. The strain gauge for the axial force test of the gas turbine is preferably a foil strain gauge, and the base material should be selected according to the working temperature of the use environment. The strain gauge with a longer grid length has the advantages of easy pasting and wiring, good heat dissipation, etc., which has a certain improvement effect on the performance of the strain gauge, but the selection of a strain gauge with a larger grid length will cause obvious measurement errors. For strain gauges with too small a grid length, the performance of strain limit creep, static measurement stability, and fatigue life will be significantly reduced. The predetermined grid length value range of the sensitive grid of the strain gauge 4 selected in this embodiment is r / 5 to r / 10, which can take into account the solution of the above-mentioned technical problems, reduce the possibility of measurement errors, and is easy to paste and wire, and has good heat dissipation.

[0066] The strain gauge used in this embodiment should be a composite strain gauge composed of a working gauge and a temperature compensation gauge, and has two sensitive grids, the two sensitive grids are axially 90° to each other, such as Figure 3 , Figure 4 As shown, the symbol P represents the working strain gauge and the symbol K represents the temperature compensation strain gauge. In order to measure the average axial force on the spring ring and generate multiple signals for comparison to avoid accidental errors, the 6 strain gauges are divided into two groups of three, evenly distributed in the patch grooves, and avoid the anti-rotation pin holes.

[0067] Specific implementation method 2: Combination Figure 1 and Figure 2 This embodiment is described. The difference between this embodiment and the first embodiment is that step S1 includes the following sub-steps:

[0068] S11. Grinding the surface of the spring ring 1 with fine sandpaper to improve the surface flatness of the spring ring 1 and ensure the quality of subsequent bonding operations; removing the surface oxide layer or dirt and enhancing the adhesion performance of the adhesive;

[0069] S12. Remove dust and oil stains on the surface of the spring ring 1 by using ethanol or acetone.

[0070] Specific implementation method three: Combination Figure 1 and Figure 2 This embodiment is described. The difference between this embodiment and the first embodiment is that step S2 includes the following sub-steps:

[0071] S21. Select the strain gauge 4 with intact sensitive grid wire; check the integrity of the sensitive grid wire of the strain gauge 4.

[0072] S22, selecting a strain gauge 4 whose resistance deviation is within the allowable range, and using an ohmmeter to measure whether the resistance deviation between the resistance of the strain gauge 4 and the nominal resistance is within the allowable range.

[0073] Specific implementation method four: Combination Figure 1 and Figure 2 This embodiment is described. The difference between this embodiment and the specific embodiment 1 is that the strain gauge 4 is a foil strain gauge 4, the base material of the strain gauge 4 is polyimide, and the material of the sensitive grid of the strain gauge 4 is Kama alloy. The selection of strain gauge resistance should be based on the heat dissipation area of ​​the strain gauge, the influence of the wire resistance, the signal-to-noise ratio, and the power consumption, usually 120Ω and 350Ω. This embodiment selects glass cloth reinforced polyimide as the base material for the spring ring of the above specifications, and the material of the sensitive grid is Kama alloy, the nominal resistance value is 350Ω, and the specification size of the sensitive grid is 1.9mm×2.5mm.

[0074] Specific implementation method five: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the first embodiment is that step S4 includes the following sub-steps:

[0075] S41, evenly apply the first adhesive layer on the surface of the non-patch groove 5 and the patch groove 3 and place them in a dry environment for 20 minutes;

[0076] S42, evenly apply a second adhesive layer on the surface of the first adhesive layer in the patch groove 3;

[0077] S43, wrapping the cloth piece on the surface of the non-patch groove 5.

[0078] Specific implementation method six: Combination Figures 1 to 7 This embodiment is described. The difference between this embodiment and the first embodiment is that step S5 includes the following sub-steps:

[0079] S51, the strain gauge 4 is placed in the middle of the patch groove 3 of the spring ring 1;

[0080] S52, fixing the strain gauge 4 and the plastic film, the silicone rubber pad and the steel sheet arranged in sequence on the upper surface of the strain gauge 4 by a clamp;

[0081] S53, placing the entire structure in S52 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour;

[0082] S54, heating the whole structure in S53 to 150°C and maintaining the temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

[0083] The thickness of the high temperature glue cannot be too thick or too thin. If the high temperature glue is too thick, it will affect the consistency of the strain gauge and the spring ring and the test accuracy. If it is too thin, it will affect the insulation between the strain gauge and the spring ring. After applying the primer, place the strain gauge in the center of the patch groove. Figure 6As shown in the figure, a layer of plastic film, silicone rubber pad and steel sheet are placed on the strain gauge in sequence, and finally clamped and fixed with a clamp. The clamp can fix the position of the strain gauge, etc. Too much clamping force will cause damage to the strain gauge. In the non-patch groove, the inner wall of the spring ring and the cloth sheet are also coated with primer in the above manner, and fixed with a clamp. Figure 7 The processed spring ring, including the fixture for fixing, is placed in a constant temperature furnace at room temperature, uniformly heated to 100°C, and kept at this temperature for 1 hour, then heated to 150°C, and kept at this temperature for 2 hours, and finally cooled naturally to room temperature in the constant temperature furnace until cooling is completed. The constant temperature furnace cannot be opened during the whole process.

[0084] Specific implementation method seven: Combination Figures 1 to 7 This embodiment is described. The difference between this embodiment and the first embodiment is that step S6 includes the following sub-steps:

[0085] S61, confirm that the resistance deviation of the strain gauge 4 is within the allowable range;

[0086] S62, dismantle the fixture fixed on the strain gauge 4 as well as the plastic film, the silicone rubber pad and the steel sheet;

[0087] S63, after the glue layer is evenly applied on the upper surface of the strain gauge 4, the cloth piece is wrapped on the surface of the patch groove 3;

[0088] S64, placing the entire structure in S63 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour;

[0089] S65, heating the whole structure in S64 to 150°C and maintaining the constant temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

[0090] Take out the spring ring that has been cured at high temperature, use an ohmmeter to check whether the resistance values ​​of all strain gauges meet the tolerance range of the nominal resistance after baking, remove the fixture and plastic film, silicone rubber pad and steel sheet after confirmation, and then brush high temperature glue on the surface of the strain gauge and the cloth sheet in the above manner, and then stick the cloth sheet on the strain gauge, and then put a layer of plastic film, silicone rubber pad and steel sheet on the strain gauge in turn according to the above method, and finally clamp it with a fixture. Then place the processed spring ring including the fixture for fixing in a constant temperature furnace at room temperature, repeat the above high temperature curing process, evenly heat to 100℃, and keep it at a constant temperature for 1 hour, then heat it to 150℃, and keep it at a constant temperature for 2 hours, and finally cool it naturally to room temperature with the constant temperature furnace until the cooling is completed. The constant temperature furnace cannot be opened during the whole process.

[0091] Take out the spring ring after the second high temperature curing. Figure 8As shown, use the ohmmeter again to check whether the resistance value of the strain gauge meets the tolerance range of the nominal resistance after baking. After confirmation, remove the clamp and plastic film, silicone rubber pad and steel sheet, retain the cloth sheet at the strain gauge part of the patch groove, scrape off all the high-temperature glue on the outside of the cloth sheet, and retain the glue on the inner wall of the spring ring at the non-patch groove, so that when wiring is convenient later, the glue on the inner wall of the spring ring can be used to fix the lead. After the above operations, the patch curing and insulation protection of this embodiment are completed. At this time, it is necessary to detect the thickness of the strain gauge after applying the high-temperature glue twice, and the total thickness should not exceed 0.5mm. Too thick will affect the force measurement accuracy of the dynamometer.

[0092] Specific implementation method eight: Combination Figures 1 to 8 This embodiment is described. The difference between this embodiment and the first embodiment is that step S7 includes the following sub-steps:

[0093] S71, dividing the fixed strain gauges 4 into two groups, and each group of strain gauges 4 is connected in series;

[0094] S72, during wiring, the leads 6 of the strain gauge 4 are laid flat, and the leads 6 are not allowed to overlap. After the wiring is completed, the joints between the two strain gauges 4 are welded using a spot welder;

[0095] S73, placing the entire structure in S72 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour;

[0096] S74, heating the whole structure in S74 to 150°C and maintaining the constant temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

[0097] The strain gauges are grouped in groups of three and connected in series to output three evenly arranged strain values. When wiring, the leads of the strain gauges must be laid flat and close to the inner wall of the spring ring, and the leads are not allowed to overlap. After the wiring is completed, use a spot welder to weld the joints between the two strain gauges. Apply high-temperature glue on both sides, the inner wall and the cloth sheet of the spring ring again according to the above method, and then repeat the above high-temperature curing process, evenly heat to 100°C, and keep the temperature constant for 1 hour, then heat to 150°C, and keep the temperature constant for 2 hours, and finally cool naturally to room temperature with the constant temperature furnace until the cooling is completed. The constant temperature furnace cannot be opened during the whole process. After the high-temperature curing is completed, take out the spring ring, use an ohmmeter to detect whether the resistance values ​​of all strain gauges meet the tolerance range of the nominal resistance after baking, and after confirmation, use tools to scrape off all the cloth sheets and glue except for the fixed leads of the inner ring of the spring ring and the patch to protect the strain gauge. The spring ring and leads must not be damaged during the process.

[0098] Specific implementation method nine: Combination Figures 1 to 9This embodiment is described. The difference between this embodiment and the first embodiment is that the external lead wire in step S8 uses a 6-core wire. After the strain gauge 4 is connected to the external lead wire, the joints are welded by a spot welding machine.

[0099] The resistance value of a strain gauge installed on a test piece without any external force or constraints will change when the ambient temperature changes. This is called thermal output. Thermal output is the largest source of error in static strain measurement, and the dispersion of thermal output will also increase with the increase of thermal output value. When there is a temperature gradient or transient in the test environment, the difference will be even greater. Therefore, this embodiment uses a composite strain gauge with temperature self-compensation function. When the temperature self-compensating strain gauge matches the test piece material, there is no need to correct the thermal output within the compensation temperature range. However, in practice, the test piece material of the gas turbine is usually different from the temperature self-compensating strain gauge. This embodiment uses a half-bridge circuit to connect the external leads to eliminate the influence of thermal output. The wiring method of a single composite strain gauge is as follows: Fig. 9 The external lead wires of this embodiment use 6-core wires, which are divided into red wire, yellow wire, gray wire, blue wire, white wire and green wire. The 6-core wires are divided into two groups, where the red wire, yellow wire and gray wire are used to connect Figure 3 The blue, white and green wires are used to connect the leads of the strain gauges 1, 3 and 5 in series. Figure 3 The leads of the middle strain gauges 2, 4, and 6 in series, the green wire of the strain gauge 1p, and the red wire of the strain gauge 1k are connected to the red wire and gray wire of the external leads respectively, and the red wire and gray wire are then connected through Fig. 9 The middle leads 1 and 3 can be connected in reverse. The green line of the strain gauge 5k and the red line of the strain gauge 5p need to be combined into one line and connected to the yellow line of the outer lead. Fig. 9 The green wire of strain gauge 2p and the red wire of strain gauge 2k are connected to the blue wire and green wire of the outer lead respectively, and the blue wire and green wire of the outer lead are connected through Fig. 9 The middle leads 1 and 3 are connected to another bridge and can be reversed. The green line of the strain gauge 6k and the red line of the strain gauge 6p need to be combined into one line and connected to the white line of the outer lead. The white line of the outer lead is then connected to Fig. 9 After the strain gauge in the spring ring is connected to the external lead, a spot welder is used to weld the joints. Finally, high-temperature glue is applied to the welded joints in the above manner, cloth is laid, and high-temperature curing is performed in a constant temperature furnace for protection.

[0100] After connecting the external leads and final curing, this patent needs to test the resistance between the external leads 6 and the cores again to confirm whether the wiring and insulation protection are intact. The 6 cores are divided into two groups as mentioned above, and their resistance values ​​are measured separately. The resistance value of the single strain gauge used is R. The resistance value between the leads should be as shown in the table below. Due to the resistance of the wire, the measured value should be slightly greater than the resistance value in the table below.

[0101]

[0102] Table 1 Lead resistance values

[0103] Oil immersion test: After the above process, the dynamometer used to measure the axial force of the gas turbine has been prepared. The insulation performance of the dynamometer needs to be tested under the working conditions of the installation. It needs to be immersed in lubricating oil at the highest working temperature for 30 minutes, and the resistance value between the leads is tested at this temperature. The resistance value should be consistent with the resistance value in Table 1, otherwise it means that the insulation performance of the dynamometer under the working environment cannot meet the test requirements.

[0104] Specific implementation method ten: Combination Figures 1 to 7 This embodiment is described. The difference between this embodiment and the first embodiment is that the strain gauge 4 includes a working piece and a temperature compensation piece, and the sensitive grid of the working piece and the sensitive grid of the temperature compensation piece are arranged vertically. When the temperature self-compensating strain gauge matches the specimen material, it is not necessary to correct the heat output within the compensation temperature range.

[0105] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a dynamometer for testing the axial force of a gas turbine, characterized in that It includes the following steps: S1. Grind and clean the surface of the spring ring (1); S2, selecting a strain gauge (4) that meets a predetermined resistance value range; S3, selecting a strain gauge (4) that meets the predetermined range of the sensitive grid length value, the inner ring radius of the spring ring (1) is r, and the predetermined range of the sensitive grid length value of the strain gauge (4) is r / 5 to r / 10; S4, the surface of the non-patch groove (5) of the spring ring (1) is coated with glue and then wrapped with a cloth piece, and the surface of the patch groove (3) of the spring ring (1) is coated with glue; S5, after the strain gauge (4) is fixed to the patch groove (3) of the spring ring (1), the whole structure is heated up, maintained at a constant temperature, and cooled down to solidify in sequence; S6, the surface of the strain gauge (4) is wrapped with a cloth; S7, routing and wiring the leads (6) of the fixed strain gauge (4); S8. Connect the strain gauge (4) to the external lead wire.

2. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 1, characterized in that: Step S1 includes the following steps: S11, grinding the surface of the spring ring (1) using fine sandpaper; S12. Remove dust and oil stains on the surface of the spring ring (1) using ethanol or acetone.

3. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 1, characterized in that: Step S2 includes the following steps: S21, select a strain gauge with a complete sensitive grid wire (4); S22. Select a strain gauge (4) whose resistance deviation is within the allowable range.

4. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 3, characterized in that: The strain gauge (4) is a foil strain gauge (4), the base material of the strain gauge (4) is polyimide, and the material of the sensitive grid of the strain gauge (4) is kama alloy.

5. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 1, characterized in that: Step S4 includes the following steps: S41, evenly applying a first adhesive layer on the surface of the non-patch groove (5) and the patch groove (3), and leaving them in a dry environment for 20 minutes; S42, evenly applying a second adhesive layer on the surface of the first adhesive layer in the patch groove (3); S43, wrapping the cloth piece on the surface of the non-patch groove (5).

6. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 1, characterized in that: Step S5 The following steps are included: S51, the strain gauge (4) is placed in the middle of the patch groove (3) of the spring ring (1); S52, fixing the strain gauge (4) and the plastic film, the silicone rubber pad and the steel sheet arranged in sequence on the upper surface of the strain gauge (4) by means of a clamp; S53, placing the entire structure in S52 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour; S54, heating the whole structure in S53 to 150°C and maintaining the temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

7. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 1, characterized in that: Step S6 includes the following steps: S61, confirming that the resistance deviation of the strain gauge (4) is within the allowable range; S62, dismantle the clamp fixed on the strain gauge (4) as well as the plastic film, the silicone rubber pad and the steel sheet; S63, after applying a layer of glue evenly on the upper surface of the strain gauge (4), wrap the cloth piece on the surface of the patch groove (3); S64, placing the entire structure in S63 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour; S65, heating the whole structure in S64 to 150°C and maintaining the constant temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

8. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 1, characterized in that: Step S7 includes the following steps: S71, dividing the fixed strain gauges (4) into two groups, and each group of strain gauges (4) is connected in series; S72. During wiring, the leads (6) of the strain gauge (4) are laid flat, and the leads (6) are not allowed to overlap. After the wiring is completed, a spot welder is used to weld the joints between the two strain gauges (4); S73, placing the entire structure in S72 in a constant temperature furnace, uniformly heating it to 100° C., and maintaining the constant temperature for 1 hour; S74, heating the whole structure in S74 to 150°C and maintaining the constant temperature for 2 hours, and finally cooling naturally to room temperature in the constant temperature furnace.

9. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 1, characterized in that: The external lead wire in step S8 uses a 6-core wire. After the strain gauge (4) is connected to the external lead wire, the joints are welded by a spot welding machine.

10. The method for manufacturing a dynamometer for testing the axial force of a gas turbine according to claim 1, characterized in that: The strain gauge (4) comprises a working gauge and a temperature compensation gauge, and the sensitive grid of the working gauge and the sensitive grid of the temperature compensation gauge are arranged vertically.

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