Aero-engine rotor stress testing device and method

Abstract

The invention provides an aero-engine rotor stress testing device and method, and belongs to the technical field of stress testing devices.The aero-engine rotor stress testing device comprises an experimental platform, and the experimental platform is provided with a motor, a transmission shaft and a turbine disc assembly which are in transmission connection in sequence; a heating furnace is arranged on the experimental platform, and the turbine disc assembly is mounted in the heating furnace; strain gauges are installed in the circumferential direction and the radial direction of the turbine disc assembly. The heating furnace is arranged on the experiment platform, and the turbine disc assembly is installed in the heating furnace; strain gauges are installed in the circumferential direction and the radial direction of the turbine disc assembly, the real working environment of the aero-engine rotor is simulated through the heating furnace, and then the internal stress level of the connecting structure position of the aero-engine rotor in the real temperature environment, the change rule of stress along with the temperature, the change of the connecting state and the like are simulated. Effective evaluation of the influence of the environment temperature on the dynamic characteristics, the connection structure strength, the connection rigidity and the like of the aero-engine rotor can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of stress testing devices, and in particular relates to an aero-engine rotor stress testing device and method. Background Art

[0002] The dynamic characteristics of an aeroengine rotor system are crucial to its high-speed development, stability, and reliability. Key parameters for evaluating rotor dynamics include rotor vibration, critical speed distribution, and structural strength. Aeroengine rotors typically operate in high-temperature environments, where deformation, changes in stress distribution, and changes in connection state directly impact rotor vibration, critical speed distribution, and structural strength. Understanding the internal stress levels at the rotor connection structure under different temperatures, how stress changes with temperature, and changes in connection state can effectively assess the impact of ambient temperature on rotor dynamics, connection strength, and connection stiffness.

[0003] Currently, there is no research on the high-temperature steady-state stress measurement of aircraft engine rotor connection structures. Most aircraft engine rotors are directly tested for rotor dynamics characteristics at room temperature, and the rotor dynamics characteristics results obtained at room temperature are used as the basis for aircraft engine rotor design and whole-machine testing. However, this is different from the dynamic characteristics of aircraft engine rotors in real working environments.

[0004] Therefore, a device and method are needed to test the stress of an aerospace engine rotor in a real working environment. Summary of the Invention

[0005] In response to the above problems, the present invention proposes an aircraft engine rotor stress testing device, comprising an experimental platform, on which are provided a motor, a transmission shaft and a turbine disk assembly that are sequentially connected in a transmission manner; a heating furnace is provided on the experimental platform, and the turbine disk assembly is installed inside the heating furnace; strain gauges are installed in both the circumferential and radial directions of the turbine disk assembly.

[0006] Furthermore, the experimental platform is provided with a turbine disk support and a bearing seat support, the turbine disk support is provided with a turbine disk transition section inside, and the inner ring of the turbine disk transition section is rotatably connected to the turbine disk assembly; the bearing seat support is provided with a bearing seat transition section inside, and the inner ring of the bearing seat transition section is rotatably connected to the drive shaft.

[0007] Furthermore, the rotor stress testing device also includes a first bearing, a second bearing and a third bearing. The first bearing and the second bearing are both installed between the turbine disk assembly and the turbine disk transition section, and the third bearing is installed between the bearing seat transition section and the drive shaft. A second thermocouple is fixedly installed on the first bearing, the second bearing and the third bearing.

[0008] Furthermore, the turbine disc assembly includes a first turbine disc and a second turbine disc, the second turbine disc is connected to the first turbine disc by means of large interference fit centering and bolt connection, and the first turbine disc and the second turbine disc are both rotatably mounted inside the heating furnace.

[0009] Furthermore, a heating cavity is provided on the end surface of the heating furnace, and a heating wire is provided in the heating cavity.

[0010] Furthermore, the rotor stress testing device also includes a vacuum box, which is installed outside the motor, the transmission shaft, the heating furnace and the experimental platform.

[0011] Furthermore, the upper surface of the strain gauge is coated with a first coating.

[0012] A method for testing the rotor stress of an aero-engine, using the above-mentioned device, comprises the following steps: Get the test temperature of the heating furnace , adjust the internal pressure of the vacuum box to ; Start the heating furnace and heat to and maintain this condition until all fourth thermocouples on the turbine disk assembly reach , then keep the time period t; Turn off the heating furnace and start cooling; If the temperature in the heating furnace is lower than t1, turn off the vacuum pump and release air into the vacuum box until the pressure in the vacuum box reaches atmospheric pressure. Then open the cover of the vacuum box and wait for the turbine disk assembly to cool to room temperature. Record the temperature and strain values during the entire heating and cooling process; Repeat the steps of obtaining the test temperature of the heating furnace and adjusting the pressure of the vacuum box until the temperature values and strain values at all the test temperatures of the heating furnace are obtained.

[0013] Furthermore, obtaining the test temperature of the heating furnace includes the following steps: Adjust the pressure inside the vacuum box to , get the bearing limit temperature as ; Setting the temperature Set the target temperature value and start the heating furnace to heat up, and adjust in real time during the heating process , so that the temperature of all fourth thermocouple measuring points reaches And keep it stable, record the heating control end at this time The setting value is ; If the bearing temperature does not reach , then set the temperature is the target temperature value, and > , repeatedly start the heating furnace to heat up, and adjust in real time during the heating process , so that the temperature of all fourth thermocouple measuring points reaches And keep it stable, record the heating control end at this time Setting value Steps to get the temperature control end Setting value ; If the bearing temperature reaches , stop heating and terminate the temperature calibration test, and record the heating control terminal at this time The set value of Turn off the heating furnace and start cooling; If the temperature in the heating furnace is lower than t1, turn off the vacuum pump and release air into the vacuum box until the pressure in the vacuum box reaches atmospheric pressure, then open the cover of the vacuum box and wait for the turbine disk assembly to cool to room temperature.

[0014] Furthermore, the strain value calculation formula is as follows:

[0015] in, represents the mechanical strain caused by steady-state mechanical load; Thermal constraint strain (the main focus) refers to the strain caused by mutual compression or stretching of connected parts due to inconsistent deformation after thermal expansion. Indicates the instantaneous temperature strain heat output, which refers to the heat output of the strain gauge caused by the instantaneous sensitive grid and the surface temperature of the specimen not reaching consistency when the heat flow passes through; Indicates the steady-state heat output, which is the heat output of the strain gage due to the free expansion of the strain gage and the test piece material and the change of the resistance temperature coefficient of the strain gage with temperature.

[0016] Beneficial effects: The aircraft engine rotor stress testing device of the present invention is provided with a heating furnace on an experimental platform, and a turbine disk assembly is installed inside the heating furnace; strain gauges are installed in the circumferential and radial directions of the turbine disk assembly. The heating furnace is used to simulate the actual working environment of the aircraft engine rotor, and then the internal stress level, stress change law with temperature, and connection state change of the aircraft engine rotor connection structure under the actual temperature environment are simulated, thereby realizing effective evaluation of the influence of ambient temperature on the dynamic characteristics, connection structure strength and connection stiffness of the aircraft engine rotor.

[0017] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of an aero-engine rotor stress testing device according to an embodiment of the present invention is shown.

[0020] Figure 2 A schematic diagram of a motor, a transmission shaft, and a turbine disk assembly in an embodiment of the present invention is shown.

[0021] Figure 3 A schematic diagram of a turbine disk assembly according to an embodiment of the present invention is shown.

[0022] Figure 4 A schematic diagram of a heating furnace in an embodiment of the present invention is shown.

[0023] Figure 5 Shown Figure 4 Schematic cross-section diagram.

[0024] Figure 6 A schematic diagram of a bearing seat support in an embodiment of the present invention is shown.

[0025] Figure 7 A schematic diagram of a turbine disk support in an embodiment of the present invention is shown.

[0026] Figure 8 A schematic diagram of a bearing seat transition section in an embodiment of the present invention is shown.

[0027] Figure 9A schematic diagram of a turbine disk transition section in an embodiment of the present invention is shown.

[0028] Figure 10 A schematic diagram of a high-temperature steady-state stress test solution for a power turbine rotor in an embodiment of the present invention is shown.

[0029] Figure 11 A schematic diagram showing the installation of sensors in an embodiment of the present invention is shown.

[0030] Figure 12 A schematic diagram of a strain gauge and leads in an embodiment of the present invention is shown.

[0031] Figure 13 A schematic diagram of adhesive installation of a strain gauge in an embodiment of the present invention is shown.

[0032] Figure 14 A schematic diagram of the installation of a compensating strain gauge in an embodiment of the present invention is shown.

[0033] Figure 15 A schematic diagram showing the locations of strain gauges and thermocouple test points on a turbine disk assembly in an embodiment of the present invention is shown.

[0034] Figure 16 A schematic diagram of a power turbine rotor test solution under normal temperature conditions according to an embodiment of the present invention is shown.

[0035] Figure 17 A schematic flow chart of a method for testing the stress of an aero-engine rotor in an embodiment of the present invention is shown.

[0036] In the figure, 21, motor; 22, drive shaft; 23, turbine disk assembly; 231, first turbine disk; 232, second turbine disk; 233, bolt; 234, self-locking nut; 24, heating furnace; 241, heating cavity; 242, heating wire; 251, first thermocouple; 252, strain gauge; 253, second thermocouple; 254, third thermocouple; 255, fourth thermocouple; 26, experimental platform; 261, turbine disk support; 262, bearing seat support; 263, bearing seat adapter section; 264, turbine disk adapter section; 27, vacuum box; 281, first coating; 282, second coating; 291, first bearing; 292, second bearing; 293, third bearing. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0038] Example 1, refer to Figure 1 A device for testing the rotor stress of an aircraft engine includes an experimental platform 26, on which a motor 21, a transmission shaft 22 and a turbine disk assembly 23 are sequentially connected; a heating furnace 24 is provided on the experimental platform 26, and the turbine disk assembly 23 is installed inside the heating furnace 24; strain gauges 252 are installed in the circumferential and radial directions of the turbine disk assembly 23.

[0039] Specifically, in order to realistically simulate the connection between the first turbine disk 231 and the second turbine disk 232, the temperature environment and installation state under working conditions, a high-temperature steady-state stress test of the key connection parts of the turbine disk assembly 23 is directly performed on a horizontal high-speed rotation tester. To this end, a special heating furnace 24, bearing seat adapter section 263 and turbine disk adapter section 264 need to be designed. The schematic diagram of the scheme is shown in Figure 1 .

[0040] Furthermore, a turbine disk support 261 and a bearing seat support 262 are provided on the experimental platform 26. A turbine disk adapter section 264 is provided inside the turbine disk support 261, and the inner ring of the turbine disk adapter section 264 is rotatably connected to the turbine disk assembly 23; a bearing seat adapter section 263 is provided inside the bearing seat support 262, and the inner ring of the bearing seat adapter section 263 is rotatably connected to the drive shaft 22.

[0041] Specifically, the test adapter section is mainly composed of the mounting support (turbine disk support 261 and bearing seat support 262), the adapter tooling (bearing seat adapter section 263 and turbine disk adapter section 264), etc. The mounting support (turbine disk support 261 and bearing seat support 262) plays the role of supporting the transmission shaft 22 during the test, including the turbine disk support 261 (refer to Figure 7 ) and bearing support 262 (reference Figure 6 ) two parts, the adapter tooling (bearing seat adapter section 263 and turbine disk adapter section 264) is used to achieve the connection between the power transmission shaft 22 and the mounting support, mainly including the bearing seat adapter section 263 (reference Figure 8 ) and turbine disk adapter 264 (reference Figure 9 ) two parts, by providing the bearing seat adapter section 263 and the turbine disk adapter section 264, it is convenient to install the second thermocouple 253 on the first bearing 291, the second bearing 292 and the third bearing 293, thereby facilitating the testing of the temperature of the first bearing 291, the second bearing 292 and the third bearing 293, and preventing the bearings from being damaged due to exceeding the withstanding temperature of the first bearing 291, the second bearing 292 and the third bearing 293. Figure 1The rotor stress testing device also includes a first bearing 291, a second bearing 292 and a third bearing 293. The first bearing 291 and the second bearing 292 are both installed between the turbine disk assembly 23 and the turbine disk adapter section 264. The third bearing 293 is installed between the bearing seat adapter section 263 and the drive shaft 22. A second thermocouple 253 is fixedly installed on the first bearing 291, the second bearing 292 and the third bearing 293.

[0042] refer to Figure 11 , by welding thermocouples at the corresponding positions, measure the outer ring of bearing 1# ( ), squirrel cage springs near the outer rings of 5# and 6# bearings (respectively and ) temperature (due to insufficient space on the outer rings of bearings 5# and 6# to weld thermocouples, the temperature of the squirrel cage spring support near them is measured) to monitor the rotor bearing temperature and prevent the bearing from overheating. The schematic diagram of the position of each measuring point is shown in Figure 11 .

[0043] refer to Figure 3 The turbine disk assembly 23 includes a first turbine disk 231 and a second turbine disk 232. The second turbine disk 232 is connected to the first turbine disk 231 by means of a large interference fit stop and bolts 233. The large interference fit stop is used to ensure that the first and second turbine disks 231, 232 are accurately aligned (centered) and form a stable connection. The first and second turbine disks 231, 232 are both rotatably mounted inside the heating furnace 24. Specifically, a certain turboshaft engine rotor is a high-speed flexible rotor operating at a speed exceeding the second-order bending critical speed. It is mainly composed of a two-stage power turbine disk assembly 23, a short shaft, a transmission shaft 22, and a torque measurement unit. Its structural diagram is shown in FIG. Figure 2 .

[0044] refer to Figure 3 The connection between the first turbine disk 231 and the second turbine disk 232 is a critical connection point for the turbine disk assembly 23 to operate in high-temperature environments. The second turbine disk 232 is connected to the first turbine disk 231 through a large interference fit and bolts 233. Specifically, the second turbine disk 232 and the front drum flange of the first turbine disk 231 are secured together by 14 circumferentially distributed, flush-cut bolts 233 (M5×0.8 with self-locking nuts 234).

[0045] refer to Figure 4 The end surface of the heating furnace 24 is provided with a heating cavity 241, and a heating wire 242 is provided in the heating cavity 241. Specifically, the heating furnace 24 is installed on the horizontal high-speed rotation tester platform to heat the turbine disk assembly 23 and test the third thermocouple 254 (there are two third thermocouples 254, which can test the third thermocouple 254). and ) Monitor the temperature and test the turbine disk assembly 23 to reach the required test temperature. In order to improve the structural reliability and installation operability of the heating furnace 24, the heating furnace 24 and its supporting structure are designed as an integrated whole, and the furnace body is divided into two halves (refer to Figure 5 ), mainly composed of upper furnace body, lower furnace body, left upper cover, left lower cover, right upper cover, lower cover and corresponding connecting structures.

[0046] refer to Figure 10 The rotor stress testing apparatus further includes a vacuum box 27, which is mounted outside the motor 21, transmission shaft 22, heating furnace 24, and experimental platform 26. The vacuum box 27 is provided with a lid and a vacuum pump. The vacuum pump draws air from the vacuum box 27 to create a near-vacuum environment, thereby simulating an actual operating environment.

[0047] refer to Figure 14 A strain gauge 252 is provided on the first turbine disk 231, and the upper surface of the strain gauge 252 is coated with a first coating 281, or a second coating 282 is provided on the first turbine disk 231, and a strain gauge 252 is installed on the second coating 282, and the upper surface of the strain gauge 252 is coated with the first coating 281.

[0048] refer to Figure 11 , in the figure: ~ For strain gauge 252, ~ The bearing temperature is measured by thermocouples (i.e., second thermocouples 253). The three second thermocouples 253 are respectively located at Figure 11 middle 、 location; ~ A thermocouple for measuring the temperature of the first turbine disk 231 (ie, the fourth thermocouple 255 ), ~ A thermocouple for measuring the temperature of the transmission shaft 22 (i.e., the first thermocouple 251); A thermocouple (i.e., the third thermocouple 254) is used to measure the temperature of the interior space of the heating furnace 24. The third thermocouple 254 is used to measure the temperature of the furnace wire surface of the heating furnace 24 .

[0049] Example 2, refer to Figure 17 A method for testing the stress of an aero-engine rotor, using the apparatus described in Example 1, comprises the following steps: Get the test temperature of the heating furnace 24 , adjust the internal pressure of the vacuum box 27 to (close to vacuum pressure); Start heating furnace 24 and heat to and maintain until all fourth thermocouples 255 on the turbine disk assembly 23 reach , then keep the time period t; Turn off the heating furnace 24 and start cooling until the temperature inside the heating furnace 24 is lower than t1; If the temperature in the heating furnace 24 is lower than t1, the vacuum pump is turned off and air is released into the vacuum box 27 until the pressure in the vacuum box 27 reaches atmospheric pressure. Then, the cover of the vacuum box 27 is opened and the turbine disk assembly 23 is cooled to room temperature. Record the temperature and strain values during the entire heating and cooling process; The steps of obtaining the test temperature of the heating furnace 24 and adjusting the pressure of the vacuum box 27 are repeated until the temperature values and strain values at the test temperatures of all the heating furnaces (24) are obtained.

[0050] Furthermore, obtaining the test temperature of the heating furnace 24 includes the following steps: Adjust the internal pressure of the vacuum box 27 to (close to vacuum pressure), obtain the limiting temperature of the bearings (including the first bearing 291, the second bearing 292 and the third bearing 293) as ; Setting the temperature The target temperature is set and the heating furnace 24 is started to heat up. During the heating process, the temperature is adjusted in real time. , so that the temperature of all the fourth thermocouple 255 measuring points reaches And keep it stable, record the heating control end at this time The setting value is ; If the bearing temperature does not reach , then set the temperature is the target temperature value, and > , repeatedly start the heating furnace 24 to heat up, and adjust in real time during the heating process , so that the temperature of all the fourth thermocouple 255 measuring points reaches And keep it stable, record the heating control end at this time Setting value Steps; If the bearing temperature reaches , stop heating and terminate the temperature calibration test, and record the heating control terminal at this time The setting value of

[0051] The heating furnace 24 is turned off and the temperature is lowered until the temperature inside the heating furnace 24 is lower than t1, that is, t1 is 60°C; If the temperature in the heating furnace 24 is lower than t1, the vacuum pump is turned off and air is released into the vacuum box 27 until the pressure in the vacuum box 27 reaches atmospheric pressure. Then, the cover of the vacuum box 27 is opened and the turbine disk assembly 23 is cooled to room temperature.

[0052] Strain measurement Four strain measurement points were set on the first stage disk of the power turbine ( ~ ), strain gauge 252 test and lead diagram see Figure 12 , see the location diagram Figure 14 , the layout of strain measurement points is shown in Table 1.

[0053] Table 1 shows the layout of strain measurement points

[0054] The connection part of the first-stage disk of the power turbine undergoes thermal expansion under high temperature and is constrained by the assembly of surrounding parts, resulting in thermal constraint deformation. At the same time, the steady-state mechanical load caused by initial interference, torque, etc. will also cause deformation of the measuring point position. The sensitive grid resistance and sensitivity coefficient of the strain gauge will also cause steady-state and transient heat output due to the rapid change of high temperature.

[0055] The strain gauge value calculation formula is as follows: ; in, Represents the mechanical strain due to steady-state mechanical loading; in this test, the mechanical strain due to steady-state mechanical loading is zero. Thermal constraint strain (the main focus) refers to the strain caused by mutual compression or stretching of connected parts due to inconsistent deformation after thermal expansion. In this test, it is mainly near the bolt holes. Due to the differences in thermal expansion coefficients between the power turbine first-stage disk, the flattened bolts on both sides, and the hexagonal self-locking nuts, the free expansion is thermally constrained and strain is generated. Indicates the instantaneous temperature strain heat output, which refers to the heat output of the strain gauge 252 caused by the instantaneous temperature difference between the sensitive grid and the test piece surface when the heat flow passes through. The influence of the instantaneous temperature strain error can be basically eliminated by keeping the temperature for a long time (more than 30 minutes) in steady state. Indicates the steady-state heat output, which refers to the heat output of the strain gauge 252 due to the free expansion of the strain gauge 252 and the test piece material and the change of the resistance temperature coefficient of the strain gauge 252 with temperature (the total proportion can reach more than 98%). In this test, the strain measurement point ( ~ ) positions are attached with two strain gauges 252 in parallel to form a half-bridge test bridge circuit for correction. That is, the strain gauge 252 to be tested deforms with the first turbine disc 231 (see the installation diagram for details). Figure 13 ), the compensation strain gauge 252 does not deform with the first turbine disk 231 (see the installation diagram Figure 14 ), is simply fixed on the first turbine disk 231 to sense the strain caused by temperature, thereby compensating the steady-state heat output of the test point and the heat output brought by the lead material.

[0056] Example 3, combined with Example 2, the preparations before the measurement test are as follows: S11, decompose the power turbine rotor into: bearing seat assembly and transition section assembly, power output and torque measurement unit, power turbine two-stage rotor assembly) and power turbine stub shaft assembly, etc.

[0057] S12, clean the two-stage rotor assembly of the power turbine, press Figure 15 The position shown requires that a strain gauge 252 be attached to the first turbine disk 2311. Strain gauge 252 is attached to the first turbine disk 231 using strain adhesive (Model M-BOND 610). After attachment, the strain gauge 252 is placed in an oven (175°C) for curing once (2.5 hours). After attachment, a layer of protective adhesive (first coating 281) (Model EPOXYLITE 813) is applied to the outer surface of the strain gauge 252 to protect it. After this, the strain gauge 252 is placed in an oven (175°C) for curing twice (4 hours each). To prevent the strain gauge 252 from failure due to the pulling force of the strain measurement wires, a titanium alloy pressing sheet (0.18 mm thick) is spot-welded to the first turbine disk 231 next to the strain gauge 252.

[0058] S13 , completing the pasting / welding and fixing of the power turbine disc (the first turbine disc 231 and the second turbine disc 232 ) and the thermocouple measuring points (the fourth thermocouple 255 and the first thermocouple 251 ) on the power turbine transmission shaft 22 .

[0059] S14: Reassemble the power turbine rotor. Test-install the power turbine drive shaft 22 on a horizontal rotation tester and determine the axial positions of the front support (turbine disk support 261) and the rear support (bearing seat support 262).

[0060] S15. Secure the front and rear supports on the platform (do not move the supports during test piece installation and the actual test). Complete the installation of the power turbine drive shaft 22. Check the bearing oil supply and return conditions.

[0061] S16 , completing the installation of the heating furnace 24 and recording the characteristic dimensions between the heating furnace 24 and the power turbine transmission shaft 22 .

[0062] S17, complete the thermocouple measurement of the internal space temperature of the heating furnace 24 (Temperature control feedback loop, monitoring temperature) and heating furnace 24 furnace wire surface temperature measurement thermocouple Installation and fixation.

[0063] S18, complete the connection and debugging of strain gauge 252, thermocouple and measuring instrument (data acquisition system), etc.

[0064] Assume that the connection between the first turbine disk 231 and the second turbine disk 232 needs to be measured ( ~ )exist 、 … Steady-state stress at low to high temperatures. To ensure that the temperature of the connection reaches the target value and remains stable, a temperature calibration test must be performed on the power turbine rotor before the stress test. The steps are as follows: S21, adjust the pressure of the tester vacuum box 27 (close to vacuum) and the test oil supply pressure.

[0065] S22, check the working condition of the test system and lubrication system.

[0066] S23, the heating control end Set to a certain target temperature value and start the heating furnace 24 to heat up, and adjust in real time during the heating process The ultimate goal is to make the target temperature value ( ~ ) The temperature of the measuring points reaches And keep it stable, record the heating control end at this time Setting value . If the bearing temperature during the test ( 、 or ) do not reach the limit value, then proceed to the next step, otherwise stop heating and terminate the temperature calibration test, and record the heating control end at this time The setting value of

[0067] S24, increase the heating control end Continue heating at the target temperature value and adjust in real time during the heating process The ultimate goal is to make the target temperature value ( ~ ) The temperature of the measuring points reaches And keep it stable, record the heating control end at this time Setting value If the bearing temperature (T1, T2 or T3) does not reach the limit value during the test, proceed to the next step, otherwise stop heating and terminate the temperature calibration test, and record the heating control terminal at this time. The setting value of

[0068] S25, repeat step S23 or 24, and when the bearing temperature ( 、 or ) have not reached the limit value, obtain 、 … .

[0069] S26, turn off the heating system and start cooling, wait for the space temperature of the heating furnace 24 When the temperature drops below 60°C, turn off the vacuum pump and release air into the test chamber until the pressure in the test chamber reaches atmospheric pressure, then open the test chamber cover.

[0070] After the temperature calibration test is completed, the formal steady-state stress test is carried out. The steps are as follows: S31, adjust the pressure of the vacuum box 27 (close to vacuum) and adjust the oil supply pressure of the test section.

[0071] S32, check the working condition of the test system and lubrication system.

[0072] S33, the heating control end Set to , start the heating system and heat until ( ~ ) Temperatures reached And keep it stable (more than 30 minutes), record the monitoring data of each temperature measurement point and strain measurement point during the entire test process to the maximum extent according to the channel capacity of the test equipment, turn off the heating system and start cooling, and wait for the heating control end to When the temperature drops below 60°C, turn off the vacuum pump and release air into the test chamber until the pressure in the test chamber reaches atmospheric pressure. Then open the test chamber cover and wait for the wheel to cool to room temperature. Record the temperature and strain values during the entire heating and cooling process.

[0073] S34, according to the temperature calibration test results, the heating control terminal Set to 、 … Repeating steps (S31-S33) can obtain the steady-state stress at different temperatures in the key connection parts of the power turbine rotor. The above steps can accurately measure the steady-state stress at the connection parts of an aircraft engine rotor under different temperature environments, and determine the internal stress level at the connection parts of the aircraft engine rotor, the stress variation pattern with temperature, and the change in connection state.

[0074] In combination with Example 2 and Example 3, the temperature measurement includes the following method: by installing a thermocouple sensor at the corresponding position, the temperature of the internal space of the heating furnace 24 is measured ( ), as the feedback temperature of the heating system temperature control, measure the surface temperature of the heating furnace 24 furnace wire ( ), as a temperature monitor (to prevent the heating furnace 24 furnace wire from being damaged by excessive temperature), the position diagram is shown in Figure 11 .

[0075] By welding thermocouples at the corresponding positions, the outer ring of bearing No. 1 ( ), squirrel cage springs near the outer rings of 5# and 6# bearings (respectively and ) temperature (due to insufficient space on the outer rings of bearings 5# and 6# to weld thermocouples, the temperature of the squirrel cage spring support near them is measured) to monitor the rotor bearing temperature and prevent the bearing from overheating. The schematic diagram of the position of each measuring point is shown in Figure 11 .

[0076] By attaching high temperature tape (type: Teflon high temperature tape) to the corresponding position to fix the thermocouple, the four characteristic positions on the first turbine disk 231 ( ~ ) temperature, the location diagram of each temperature test point is shown in Figure 11 .

[0077] By welding thermocouples (first thermocouple 251) at corresponding positions on the transmission shaft 22, the four characteristic positions on the transmission shaft 22 ( ~ ) to obtain the rotor temperature distribution. The schematic diagram of the position of each measuring point is shown in Figure 11 .

[0078] The present invention has been verified by experiments. The technical solution of the present invention was used to carry out steady-state stress tests on the connection between the first and second stage disks of a turboshaft engine on a horizontal rotation tester at temperatures of 150°C, 200°C, 227°C, and 250°C, and the change pattern of stress at this position with temperature was obtained.

[0079] Figure 16 This is a schematic diagram of the structure of the present invention at room temperature, which is used to test the strain of the turbine rotor at room temperature, so as to facilitate comparison with the strain tested at high temperature.

[0080] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aero-engine rotor stress testing device, characterized in that: The invention comprises an experimental platform (26), wherein the experimental platform (26) is provided with a motor (21), a transmission shaft (22), and a turbine disk assembly (23) which are sequentially connected in transmission; a heating furnace (24) is provided on the experimental platform (26), and the turbine disk assembly (23) is installed inside the heating furnace (24); and strain gauges (252) are installed in the circumferential and radial directions of the turbine disk assembly (23).

2. The aero-engine rotor stress testing device according to claim 1, characterized in that: The experimental platform (26) is provided with a turbine disk support (261) and a bearing seat support (262), wherein a turbine disk adapter section (264) is provided inside the turbine disk support (261), and an inner ring of the turbine disk adapter section (264) is rotatably connected to the turbine disk assembly (23); and a bearing seat adapter section (263) is provided inside the bearing seat support (262), and an inner ring of the bearing seat adapter section (263) is rotatably connected to the transmission shaft (22).

3. The aero-engine rotor stress testing device according to claim 2, characterized in that: The rotor stress testing device further comprises a first bearing (291), a second bearing (292) and a third bearing (293), wherein the first bearing (291) and the second bearing (292) are both mounted between the turbine disk assembly (23) and the turbine disk adapter section (264), and the third bearing (293) is mounted between the bearing seat adapter section (263) and the transmission shaft (22), and a second thermocouple (253) is fixedly mounted on each of the first bearing (291), the second bearing (292) and the third bearing (293).

4. An aero-engine rotor stress testing device according to any one of claims 1 to 3, characterized in that: The turbine disk assembly (23) includes a first turbine disk (231) and a second turbine disk (232), wherein the second turbine disk (232) is connected to the first turbine disk (231) by means of a large interference fit stop and a bolt (233), and the first turbine disk (231) and the second turbine disk (232) are both rotatably mounted inside the heating furnace (24).

5. The aircraft engine rotor stress testing device according to claim 1, characterized in that: A heating cavity (241) is provided on the end surface of the heating furnace (24), and a heating wire (242) is provided in the heating cavity (241).

6. The aero-engine rotor stress testing device according to claim 1, characterized in that: The rotor stress testing device further comprises a vacuum box (27), which is installed outside the motor (21), the transmission shaft (22), the heating furnace (24) and the experimental platform (26).

7. The aircraft engine rotor stress testing device according to claim 1, characterized in that: The upper surface of the strain gauge (252) is coated with a first coating (281).

8. A method for testing the stress of an aero-engine rotor, characterized in that: The device according to any one of claims 1 to 7 comprises the following steps: Get the test temperature of the heating furnace (24) , adjust the internal pressure of the vacuum box (27) to ; Start the heating furnace (24) and heat it to and maintain until all fourth thermocouples (255) on the turbine disk assembly (23) reach , then keep the time period t; Turn off the heating furnace (24) and start cooling; If the temperature in the heating furnace (24) is lower than t1, the vacuum pump is turned off and air is released into the vacuum box (27) until the pressure in the vacuum box (27) reaches atmospheric pressure, and then the cover of the vacuum box (27) is opened to wait for the turbine disc assembly (23) to cool to room temperature; Record the temperature and strain values during the entire heating and cooling process; The steps of obtaining the test temperature of the heating furnace (24) and adjusting the pressure of the vacuum box (27) are repeated until the temperature values and strain values at the test temperatures of all heating furnaces (24) are obtained.

9. The method for testing the stress of an aero-engine rotor according to claim 8, characterized in that: The step of obtaining the test temperature of the heating furnace (24) comprises the following steps: Adjust the internal pressure of the vacuum box (27) to , get the bearing limit temperature as ; Setting the temperature The target temperature is set and the heating furnace (24) is started to heat the device. During the heating process, the temperature is adjusted in real time. , so that the temperature of all the fourth thermocouple (255) measuring points reaches And keep it stable, record the heating control end at this time The setting value is ; If the bearing temperature does not reach , then set the temperature is the target temperature value, and > , repeatedly start the heating furnace (24) to heat, and adjust in real time during the heating process , so that the temperature of all the fourth thermocouple (255) measuring points reaches And keep it stable, record the heating control end at this time Setting value Steps to get the temperature control end Setting value ; If the bearing temperature reaches , stop heating and terminate the temperature calibration test, and record the heating control terminal at this time The set value of Turn off the heating furnace (24) and start cooling; If the temperature in the heating furnace (24) is lower than t1, the vacuum pump is turned off and air is released into the vacuum box (27) until the pressure in the vacuum box (27) reaches atmospheric pressure. The cover of the vacuum box (27) is then opened and the turbine disc assembly (23) is cooled to room temperature.

10. The method for testing the stress of an aero-engine rotor according to claim 8, characterized in that: The strain value calculation formula is as follows: in, represents the mechanical strain caused by steady-state mechanical load; Thermal constraint strain (the main focus) refers to the strain caused by mutual compression or stretching of connected parts due to inconsistent deformation after thermal expansion. Indicates the instantaneous temperature strain heat output, which refers to the heat output of the strain gauge caused by the instantaneous sensitive grid and the surface temperature of the specimen not reaching consistency when the heat flow passes through; Indicates the steady-state heat output, which is the heat output of the strain gage due to the free expansion of the strain gage and the test piece material and the change of the resistance temperature coefficient of the strain gage with temperature.

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