Vibration frequency test bench and method for a bladed disc

Abstract

The application discloses a kind of vibration frequency test bench and method for blade disc, including for driving blade disc vibration rotor mechanism, for driving the driving device of rotor mechanism and vibration detection device, rotor mechanism includes bearing support, rotationally arranged on bearing support rotor shaft and for driving rotor shaft rotation driven helical gear, driving device includes motor support, driving motor is arranged on motor support and driven helical gear is arranged on driving motor output shaft Active helical gear, blade disc is installed on rotor shaft, active helical gear is engaged with driven helical gear, and the exciting force under meshing frequency is generated by the transmission error of active helical gear and driven helical gear, to excite the resonance of each direction of blade disc, vibration detection device is used to detect the vibration frequency of blade disc;Its structure is ingenious, can completely cover the frequency measurement requirement of measured blade disc, can accurately determine the vibration frequency of blade disc, and applicable with different models of blade disc.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular, to a vibration frequency test bench for blade disks. Furthermore, this invention also relates to a method for testing the vibration frequency of blade disks using the aforementioned vibration frequency test bench. Background Technology

[0002] High-cycle fatigue caused by vibration is a particularly prominent problem for aero-engine blade disks. According to incomplete statistics, blade disk failures account for more than half of the typical structural component failures in aero-engines. Therefore, blade disk resonance has always been a major concern in the development and use of aero-engines. As engines develop towards higher performance and higher power-to-weight ratios, the load on blade disks is increasing, and the risk of high-frequency resonance in blade disks is also increasing. Therefore, it is necessary to conduct blade disk vibration frequency measurements in the early stages of development to obtain accurate blade disk vibration frequencies and ensure the safe operation of the engine.

[0003] Existing methods for measuring the vibration frequency of bladed disks mainly include static vibration frequency measurement methods, engine overall dynamic stress measurement methods, and rotating liquid injection excitation measurement methods. These methods have the following drawbacks: 1. The static vibration frequency measurement method suffers from low accuracy because it cannot consider the stress stiffening characteristics of the blade disk in the working state (rotational state). Furthermore, for split blade disk structures (see...), the measurement results are not highly accurate. Figure 1 Because the contact stiffness of the discontinuous contact surface (tenon / groove contact surface) in the rotating state is very different from that in the static state, the accuracy of the static frequency measurement results of the split blade disk structure is lower.

[0004] 2. The method for measuring the dynamic stress of the entire engine is as follows: Since the entire engine is in a high-temperature and confined environment, it is necessary to improve each component along the test path and add a cooling device. Therefore, the vibration frequency measurement test cycle is long and the test cost is high. 3. Rotary spray excitation measurement method (see...) Figure 2A number of liquid nozzles are evenly distributed around the blade disk. During high-speed rotation of the blades, liquid is ejected from the nozzles, forming a conical liquid column to simulate the airflow excitation force under working conditions. The impact of the high-speed moving blades with the liquid column causes forced vibration of the blades. When the excitation frequency equals the blade vibration frequency, the blade vibration stress is at its maximum. At this point, the vibration frequency of the blade disk is obtained by attaching strain gauges to the blade surface. High-frequency excitation requires the fluid to rapidly change its direction of motion, but due to the mass of the fluid itself, fluid inertia hinders this rapid change. Therefore, fluid excitation at high frequencies is difficult to provide a stable excitation force. Furthermore, high-speed fluid scouring can easily cause the strain gauges attached to the blade surface to detach or fail. In addition, the liquid nozzle positions are usually fixed, making it difficult to flexibly adjust the radial or circumferential excitation positions, resulting in poor adaptability to blade disks of different sizes. Summary of the Invention

[0005] This invention provides a vibration frequency testing platform and method for blade disks, which solves the technical problems of existing blade disk vibration frequency testing methods, such as low testing accuracy, long test cycle, high test cost, difficulty in high-frequency excitation, and low strain gauge survival rate.

[0006] According to one aspect of the present invention, a vibration frequency testing bench for a blade disk is provided, comprising a rotor mechanism for driving the blade disk to vibrate, a drive device for driving the rotor mechanism, and a vibration detection device. The rotor mechanism includes a bearing support, a rotor shaft rotatably mounted on the bearing support, and a driven helical gear for driving the rotor shaft to rotate. The drive device includes a motor support, a drive motor mounted on the motor support, and a driving helical gear mounted on the output shaft of the drive motor. The blade disk is mounted on the rotor shaft, and the driving helical gear meshes with the driven helical gear. An excitation force at the meshing frequency is generated by the transmission error between the driving and driven helical gears to excite resonance in all directions of the blade disk. The vibration detection device is used to detect the vibration frequency of the blade disk.

[0007] Furthermore, a counterweight disk for changing the load of the rotor mechanism is provided on the rotor shaft, and the counterweight disk and the driven helical gear are respectively arranged on both sides of the blade disk.

[0008] Furthermore, a spacer sleeve is provided on the rotor shaft to limit the axial position of the rotor shaft so as to ensure that the driving helical gear and the driven helical gear are always meshed.

[0009] Furthermore, a shim is provided between the rotor shaft and the driven helical gear, and the shim is used to adjust the meshing position of the driven helical gear and the driving helical gear.

[0010] Furthermore, the vibration detection device includes a strain gauge, a slip ring, and a dynamic strain gauge. The strain gauge is attached to the blade surface of the blade disk, the slip ring is disposed on the end of the rotor shaft, and the strain gauge and the slip ring, as well as the slip ring and the dynamic strain gauge, are connected by wires.

[0011] According to another aspect of the present invention, a method for testing the vibration frequency of a blade disk is also provided, which utilizes the above-described vibration frequency testing bench for a blade disk. The method for testing the vibration frequency of a blade disk includes the following steps: S1. Based on the highest resonance frequency of the blade disk under working conditions, design the number of teeth of the active helical gear, and determine the maximum test speed based on the number of teeth of the active helical gear. S2. Excitation force according to the required meshing frequency The size of the driven helical gear is selected; S3. Install the blade disk and driven helical gear on the rotor shaft, and install the driving helical gear on the output shaft of the drive motor to ensure that the driving helical gear meshes with the driven helical gear; S4. Attach strain gauges to the surface of the blades on the blade disk; S5. The speed of the drive motor is accelerated uniformly to the maximum test speed by an increment of q% of the maximum test speed. The strain gauge detects the vibration frequency of the blade disk and transmits the collected information to the dynamic strain gauge. S6. The drive motor decelerates uniformly from the highest test speed in increments of q% of the highest test speed until it stops. The strain gauge detects the vibration frequency of the blade disk and transmits the collected information to the dynamic strain gauge. S7. The dynamic strain gauge processes the information collected by the strain gauges and obtains the highest frequency of the blade disk based on the spectrum analysis results.

[0012] Furthermore, the design value of the highest frequency of the blade disk in operation is equal to the meshing frequency. , Where N is the number of teeth on the driving helical gear. The rotational speed of the driving helical gear. Then test the highest speed. Where b is the speed margin correction factor, 1.1≤b≤1.3.

[0013] Furthermore, in step S2, ,in, This indicates fluctuations in meshing stiffness. Indicates the gear size transmission error. ,in, This is the stiffness correction factor. The elastic modulus of the gear material. For tooth width, For gear end face overlap, The Poisson's ratio of the gear material. ,in, This represents the dimensional error correction factor. This represents the cumulative total deviation of the tooth pitch. Accumulated total deviation by tooth pitch Select the driven helical gear with the appropriate precision.

[0014] Furthermore, step S1 also includes, according to the required axial excitation force and radial excitation force Size selection of the helix angle of the driving helical gear and pressure angle , , , The helix angle of the driving helical gear.

[0015] Furthermore, in step S1, the excitation force at the meshing frequency The value range is 500-800N, 20°≤ ≤30°, 15°≤ ≤25°; In steps S5 and S6, 0 <q≤1。

[0016] The present invention has the following beneficial effects: The vibration frequency testing platform for blade disks of the present invention comprises two bearing supports spaced apart, with the rotor shaft rotatably mounted on the two bearing supports. A driven helical gear is mounted on the rotor shaft, and a driving helical gear is mounted on the output shaft of a drive motor. In use, the drive motor drives the driving helical gear to rotate, which in turn drives the blade disk to rotate via the driven helical gear. Due to gear size transmission errors, the helical gear pair generates axial and radial meshing frequency excitations. The axial and radial excitation forces generated by the gear meshing are transmitted to the tested blade disk through the rotor shaft, thereby exciting resonance in all directions of the blade disk. When the excitation frequency equals the vibration frequency of the blade disk, the blade vibration stress is at its maximum. The accurate vibration frequency of the blade disk is obtained through a vibration detection device. Its ingenious structure employs gear meshing excitation, providing a high excitation frequency at a relatively low speed, fully covering the frequency measurement requirements of the measured blade disk. By controlling the motor speed, the excitation frequency can be precisely controlled, accurately determining the vibration frequency of the blade disk. By adjusting the mass of the counterweight disk on the rotor shaft system and the magnitude of the gear size transmission error, the measured blade disk can continuously and stably obtain high-frequency excitation energy, facilitating the collection of vibration information by the vibration detection device. The helical gear meshing can provide radial and axial excitation forces, which is more conducive to exciting resonance in all directions of the blade. It can accurately and stably control the excitation force. The overall structure of the test bench remains unchanged, and it can be directly replaced with the blade disk to be applicable to different models of blade disks, demonstrating strong adaptability.

[0017] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the bladed disk structure; Figure 2 This is a schematic diagram of the structure of an existing rotary liquid spraying excitation test system; Figure 3 This is a schematic diagram of the structure of a vibration frequency test bench for a blade disk according to a preferred embodiment of the present invention; Figure 4 This is a cross-sectional view of a vibration frequency test bench for a blade disk according to a preferred embodiment of the present invention. Figure 5 This is a schematic diagram of the spacer sleeve of a preferred embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the gasket according to a preferred embodiment of the present invention.

[0019] Legend: 100. Blade disk; 1. Rotor mechanism; 11. Bearing support; 12. Rotor shaft; 121. First shoulder; 122. Second shoulder; 13. Driven helical gear; 14. Bearing; 15. Spacer sleeve; 16. Counterweight plate; 17. Shim; 18. Pressure block; 19. Locking nut; 2. Drive unit; 21. Motor support; 22. Drive motor; 23. Drive helical gear; 3. Vibration detection device; 31. Strain gauge; 32. Slip ring; 33. Dynamic strain gauge. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, and back), the orientation or positional relationship of the directional indications is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments according to this application and simplifying the description, and is not intended to indicate or imply that the device or unit referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments according to this application.

[0022] Furthermore, if the embodiments of this invention involve descriptions using terms such as "first," "second," and "third," these terms are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," or "third" may explicitly or implicitly include at least one of those features. The term "multiple" refers to two or more unless otherwise explicitly defined. Terms such as "installed," "connected," "attached," and "fixed" should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "attached" can be a direct connection or an indirect connection through an intermediate medium.

[0023] If the words "and / or" or "and / or" appear in the text, they mean three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that satisfies both A and B. In addition, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] To better understand the above technical solution, the following detailed explanation is provided in conjunction with the accompanying drawings.

[0025] Please refer to the following: Figures 3 to 6 The vibration frequency test bench for the blade disk in this embodiment includes a rotor mechanism 1 for driving the blade disk to vibrate, a drive device 2 for driving the rotor mechanism 1, and a vibration detection device 3. The rotor mechanism 1 includes a bearing support 11, a rotor shaft 12 rotatably mounted on the bearing support 11, and a driven helical gear 13 for driving the rotor shaft 12 to rotate. The drive device 2 includes a motor support 21, a drive motor 22 mounted on the motor support 21, and a driving helical gear 23 mounted on the output shaft of the drive motor 22. The blade disk is mounted on the rotor shaft 12. The driving helical gear 23 meshes with the driven helical gear 13. The transmission error between the driving helical gear 23 and the driven helical gear 13 generates an excitation force at the meshing frequency to excite resonance in all directions of the blade disk. The vibration detection device 3 is used to detect the vibration frequency of the blade disk.

[0026] In this embodiment, the vibration frequency testing bench for the blade disk has two bearing supports 11 spaced apart. A rotor shaft 12 is rotatably mounted on the two bearing supports 11. A driven helical gear 13 is mounted on the rotor shaft 12, and a driving helical gear 23 is mounted on the output shaft of the drive motor 22. During use, the drive motor 22 drives the driving helical gear 23 to rotate, which in turn drives the blade disk 100 to rotate via the driven helical gear 13. Due to gear size transmission errors, the helical gear pair generates axial and radial meshing frequency excitations. The axial and radial excitation forces generated by the gear meshing are transmitted to the tested blade disk 100 through the rotor shaft 12, thereby exciting resonance in all directions of the blade disk 100. When the excitation frequency equals the vibration frequency of the blade disk 100, the blade vibration stress is at its maximum. This is detected by the vibration detection device. 3. Obtain accurate vibration frequency of the blade disk; its ingenious structure adopts gear meshing excitation, which can provide a high excitation frequency at a low speed, and can completely cover the frequency measurement requirements of the blade disk 100 being measured. By controlling the motor speed, the excitation frequency can be precisely controlled, and the vibration frequency of the blade disk 100 can be accurately determined. By adjusting the mass of the counterweight disk on the rotor shaft system and the size of the gears, the blade disk being measured can continuously and stably obtain high-frequency excitation energy, which is convenient for the vibration detection device 3 to collect vibration information. The helical gear meshing can provide radial and axial excitation forces, which is more conducive to exciting resonance in all directions of the blade. It can accurately and stably control the excitation force. The overall structure of the test bench remains unchanged. It can be directly replaced with blade disk 100 to be applicable to different models of blade disks, and has strong adaptability. Optionally, ball bearings 14 are arranged on the bearing support 11. The outer ring of the ball bearing 14 is connected to the bearing support 11, and the inner ring of the ball bearing 14 is connected to the rotor shaft 12. The main function of the ball bearing 14 is to support the rotation of the rotor shaft 12 and transmit the load to the bearing support 11. The ball bearings 14 are respectively arranged at the front end of the blade disk 100 under test. Figure 4 (left end) and the rear end of the driven helical gear 13 ( Figure 4 (At the right end of the middle), since the ball bearing 14 can withstand both radial and axial loads, this arrangement is conducive to the transmission of radial and axial excitation forces generated by gear meshing to the tested blade disk, thus exciting resonance in all directions of the blade disk.

[0027] In this embodiment, a counterweight disk 16 for changing the load of the rotor mechanism 1 is arranged on the rotor shaft 12. The counterweight disk 16 and the driven helical gear 13 are respectively arranged on both sides of the blade disk. Adding or removing counterweights on the circumference of the counterweight disk 16 can change the load of the rotor shaft system and serve as the balance surface for the dynamic balance of the rotor shaft system. The added counterweight disk 16 makes the resonance amplitude of the blade disk 100 more obvious. The counterweight disk 16 is located at the cantilever end (front end) of the rotor shaft 12 because the cantilever position has the greatest impact on the balance of the entire shaft system. Therefore, the dynamic balance surface of the shaft system is also selected on the counterweight disk 16, which is more conducive to ensuring that the rotor mechanism 1 is smoothly pushed up to the maximum speed. On the other hand, the counterweight disk 16 is easy to install and remove at the cantilever end. Optionally, the distance between the blade disk and the driven helical gear 13 should be as close as possible to ensure sufficient space for disassembly and assembly, so as to reduce the attenuation of the excitation force. Optionally, the counterweight disc 16 is connected to the rotor shaft 12 via a spline, which prevents relative rotation between the counterweight disc 16 and the rotor shaft 12. A locking nut 19 is provided on the rotor shaft 12 to limit the axial position of the counterweight disc 16, preventing axial movement of the counterweight disc 16. This design is simple, easy to assemble and disassemble, and facilitates the replacement of counterweight discs 16 with different weights. Optionally, a pressure block 18 is provided between the counterweight disc 16 and the locking nut 19 to prevent the locking nut 19 from wearing down the second end face of the counterweight disc 16, thus extending its service life.

[0028] like Figure 3 and Figure 4 As shown, in this embodiment, a spacer sleeve 15 is provided on the rotor shaft 12. The spacer sleeve 15 is used to limit the axial position of the rotor shaft 12, which can prevent the rotor shaft 12 from moving axially, so as to ensure that the driving helical gear 23 and the driven helical gear 13 are always meshed.

[0029] like Figure 4 and Figure 5 As shown, in this embodiment, the spacer sleeve 15 is arranged at the front end of the rotor shaft 12. The rotor shaft 12 is provided with a first shoulder 121 for abutting against the inner ring of the ball bearing 14. The spacer sleeve 15 and the first shoulder 121 abut against both sides of the inner ring of the ball bearing 14, respectively. One end of the spacer sleeve 15 abuts against the inner ring of the ball bearing 14, and the other end of the spacer sleeve 15 abuts against the counterweight plate 16. The counterweight plate 16 is locked by the locking nut 19, which can restrict the axial movement of the rotor shaft 12.

[0030] like Figure 4 and Figure 6 As shown, in this embodiment, the spacer sleeve 15 is arranged at the rear end of the rotor shaft 12. The rotor shaft 12 is provided with a second shoulder 122 for abutting against the driven helical gear 13. The spacer sleeve 15 and the rotor shaft 12 abut against the two ends of the driven helical gear 13 respectively. The end of the spacer sleeve 15 facing away from the driven helical gear 13 abuts against the inner ring of the ball bearing 14. The inner ring of the ball bearing 14 is abutted by the inner ring of the ball bearing 14, which can limit the axial movement of the rotor shaft 12.

[0031] like Figure 6 As shown, in this embodiment, a shim 17 is provided between the rotor shaft 12 and the driven helical gear 13. When the meshing imprint is at the tooth root, the thickness of the shim 17 is increased; when the meshing imprint is at the tooth tip, the thickness of the shim 17 is reduced. By adjusting the thickness of the shim 17, the load is ensured to be uniform when the gears mesh.

[0032] Optionally, the adjustment amount of shim 17 is equal to the required axial movement of the helical gear. / tan ,in, The distance by which the imprint deviates from the ideal center position. The helix angle of the driving bevel gear 23.

[0033] like Figure 4 As shown, in this embodiment, the vibration detection device 3 includes a strain gauge 31, a slip ring 32, and a dynamic strain gauge 33. The strain gauge 31 is attached to the surface of the blade of the blade disk, and the slip ring 32 is arranged on the end of the rotor shaft 12. The strain gauge 31 and the slip ring 32, and the slip ring 32 and the dynamic strain gauge 33 are connected by wires. The rotor shaft 12 is a hollow shaft, which facilitates the wiring of the strain gauge 31 and the slip ring 32. The excitation source of the blade disk is gear meshing excitation, which does not directly impact the strain gauge attached to the blade surface, resulting in a high survival rate of the strain gauge. The strain gauge 31 collects the vibration information of the blade disk 100 and transmits it to the dynamic strain gauge 33. The dynamic strain gauge 33 analyzes the vibration spectrum to the highest frequency of the blade disk.

[0034] A method for testing the vibration frequency of a bladed disk, utilizing the aforementioned vibration frequency testing bench for bladed disks, includes the following steps: S1. Based on the highest vibration frequency of the blade disk under working conditions, design the number of teeth of the active helical gear 23, and determine the maximum test speed based on the number of teeth of the active helical gear 23. S2. Excitation force according to the required meshing frequency The size of the driven helical gear is selected as 13; S3. Install the blade disk and driven helical gear 13 on the rotor shaft 12, and install the driving helical gear 23 on the output shaft of the drive motor 22 to ensure that the driving helical gear 23 meshes with the driven helical gear 13. S4. Attach strain gauges 31 to the surface of the blades of the blade disk; S5. The speed of the drive motor 22 is accelerated uniformly to the test maximum speed by an increment of q% times. The strain gauge 31 detects the vibration frequency of the blade disk and transmits the collected information to the dynamic strain gauge 33. S6. Drive motor 22 decelerates uniformly from the highest test speed in increments of q% of the highest test speed until it stops. Strain gauge 31 detects the vibration frequency of the blade disk and transmits the collected information to dynamic strain gauge 33. S7, the dynamic strain gauge 33 processes the information collected by the strain gauge 31 and obtains the highest frequency of the blade disk based on the spectrum analysis results.

[0035] The vibration frequency testing method for blade disks in this embodiment can precisely control the excitation frequency by controlling the motor speed, thus accurately determining the vibration frequency of the blade disk 100. By adjusting the mass of the counterweight disk on the rotor shaft system and the transmission error of the gear dimensions, the tested blade disk can continuously and stably obtain high-frequency excitation energy, facilitating the collection of vibration information by strain gauges. The helical gear meshing can provide radial and axial excitation forces, which is more conducive to exciting resonance in all directions of the blade. It can accurately and stably control the excitation force, is applicable to different types of blade disks, and the overall structure of the test bench remains unchanged; only the blade disk needs to be replaced, making it highly adaptable. The blade disk excitation source is gear meshing excitation, which does not directly impact the strain gauges attached to the blade surface, resulting in a high survival rate of the strain gauges. Optionally, by selecting driving helical gears 23 and / or driven helical gears 13 with different precision grades, the transmission error can be changed, thereby adjusting the magnitude of the excitation force at the meshing frequency.

[0036] In this embodiment, the design value of the highest frequency of the blade disk's operating state is equal to the meshing frequency. , Where N is the number of teeth of the driving helical gear 23. The rotational speed of the driving helical gear 23 Then test the highest speed. Where b is the speed margin correction factor, 1.1≤b≤1.3.

[0037] In this embodiment, in step S2, ,in, This indicates fluctuations in meshing stiffness. Indicates the gear size transmission error. ,in, This is the stiffness correction factor. The elastic modulus of the gear material. For tooth width, For gear end face overlap, The Poisson's ratio of the gear material. ,in, This represents the dimensional error correction factor. This represents the cumulative total deviation of the tooth pitch. Accumulated total deviation by tooth pitch Select the driven helical gear 13 corresponding to the accuracy.

[0038] In this embodiment, step S1 further includes selecting the helix angle and the pressure angle of the driving helical gear 23 according to the magnitudes of the required axial exciting force and the radial exciting force , , , is the helix angle of the driving helical gear (23)..

[0039] In this embodiment, in step S1, considering the attenuation of the exciting force transmitted to the measured blade disk, the value range of the exciting force at the meshing frequency is 500 - 800 N. When the exciting force is less than 500 N, too small an exciting force will result in poor exciting effect; when the exciting force is greater than 800 N, it will cause damage to the driving helical gear 23 and / or the driven helical gear 13; 20° ≤ ≤ 30°, 15° ≤ ≤ 25°. Appropriately increasing the angle of can increase the axial exciting force and is more conducive to exciting the axial vibration mode of the blade disk 100.

[0040] In this embodiment, in steps S5 and S6, 0 < q ≤ 1. The smaller the value of q, the more test speeds the highest test speed can be divided into, which is convenient for accurately determining the vibration frequency of the blade disk 100. Optionally, considering the control accuracy of the driving motor 22, q = 0.1 can accurately determine the vibration frequency of the blade disk 100.

[0041] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for testing the vibration frequency of a bladed disk, characterized in that, A vibration frequency testing bench for a blade disk is used. The vibration frequency testing bench for the blade disk includes a rotor mechanism (1) for driving the blade disk to vibrate, a drive device (2) for driving the rotor mechanism (1), and a vibration detection device (3). The rotor mechanism (1) includes a bearing support (11), a rotor shaft (12) rotatably mounted on the bearing support (11), and a driven helical gear (13) for driving the rotor shaft (12) to rotate. The drive device (2) includes a motor support (21), a drive motor (22) mounted on the motor support (21), and a driving helical gear (23) mounted on the output shaft of the drive motor (22). The blade disk is mounted on the rotor shaft (12). On the rotor shaft (12), the driving helical gear (23) meshes with the driven helical gear (13). The transmission error between the driving helical gear (23) and the driven helical gear (13) generates an excitation force at the meshing frequency to excite resonance in all directions of the blade disk. The vibration detection device (3) is used to detect the vibration frequency of the blade disk. The vibration detection device (3) includes a strain gauge (31), a slip ring (32), and a dynamic strain gauge (33). The strain gauge (31) is attached to the blade surface of the blade disk. The slip ring (32) is placed on the end of the rotor shaft (12). The strain gauge (31) and the slip ring (32), and the slip ring (32) and the dynamic strain gauge (33) are connected by wires. The vibration frequency testing method for the blade disk includes the following steps: S1. Based on the highest resonance frequency of the blade disk in working state, design the number of teeth of the active helical gear (23), and determine the maximum test speed by the number of teeth of the active helical gear (23); S2. Excitation force according to the required meshing frequency The size of the driven helical gear is selected (13); S3. Install the blade disk and the driven helical gear (13) on the rotor shaft (12), and install the driving helical gear (23) on the output shaft of the drive motor (22) to ensure that the driving helical gear (23) meshes with the driven helical gear (13); S4. Attach strain gauges (31) to the surface of the blades of the blade disk. S5. The speed of the drive motor (22) is accelerated uniformly to the test maximum speed by an increment of q% times the test maximum speed. The strain gauge (31) detects the vibration frequency of the blade disk and transmits the collected information to the dynamic strain gauge (33). S6. The drive motor (22) decelerates uniformly from the highest test speed by an increment of q% times the highest test speed until it stops. The strain gauge (31) detects the vibration frequency of the blade disk and transmits the collected information to the dynamic strain gauge (33). S7. The dynamic strain gauge (33) processes the information collected by the strain gauge (31) and obtains the highest frequency of the blade disk based on the spectrum analysis results. Step S1 also includes, according to the required axial excitation force and radial excitation force The size of the helix angle of the driving helical gear (23) is selected. and pressure angle , , , The helix angle of the driving helical gear (23); In step S2, ,in, This indicates fluctuations in meshing stiffness. Indicates the gear size transmission error. ,in, This is the stiffness correction factor. The elastic modulus of the gear material. For tooth width, For gear end face overlap, The Poisson's ratio of the gear material. ,in, This represents the dimensional error correction factor. This represents the cumulative total deviation of the tooth pitch. Accumulated total deviation by tooth pitch Select the driven helical gear (13) with the corresponding accuracy. In steps S5 and S6, 0 <q≤1。 2. The vibration frequency testing method for blade disks according to claim 1, characterized in that, In step S1, The design value of the highest operating frequency of the bladed disk is equal to the meshing frequency. , , Where N is the number of teeth of the driving helical gear (23), The rotational speed of the driving helical gear (23) Then test the highest speed. Where b is the speed margin correction factor, 1.1≤b≤1.

3.

3. The method for testing the vibration frequency of a blade disk according to claim 1, characterized in that, In step S1, the excitation force at the meshing frequency The value range is 500-800N, 20°≤ ≤30°, 15°≤ ≤25°.

4. The vibration frequency testing method for blade disks according to claim 1, characterized in that, The rotor shaft (12) is provided with a counterweight disk (16) for changing the load of the rotor mechanism (1). The counterweight disk (16) and the driven helical gear (13) are respectively arranged on both sides of the blade disk.

5. The vibration frequency testing method for blade disks according to claim 1, characterized in that, A spacer sleeve (15) is provided on the rotor shaft (12). The spacer sleeve (15) is used to limit the axial position of the rotor shaft (12) to ensure that the driving helical gear (23) and the driven helical gear (13) are always meshed.

6. The method for testing the vibration frequency of a blade disk according to claim 1, characterized in that, A shim (17) is provided between the rotor shaft (12) and the driven helical gear (13). The shim (17) is used to adjust the meshing position of the driven helical gear (13) and the driving helical gear (23).

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