A non-contact fatigue testing device with adjustable centrifugal load

Abstract

The application discloses a kind of fatigue testing devices of non-contact adjustable centrifugal load, belong to centrifugal testing technical field, it includes: test frame, it is set as L-shaped structure;Fixed frame is fixed on the test frame, two bearing seats are vertically distributed on the fixed frame;Main shaft, vertically through connection between two bearing seats;Centrifugal regulation unit is rotatably installed on the fixed frame, the upper end of the main shaft is connected with the centrifugal regulation unit;Belt driving device is installed on the test frame, and the lower end of the main shaft is connected with the transmission of belt driving device;Connecting shaft is fixed in the center of the upper end of the centrifugal regulation unit;The application can realize the non-contact continuous adjustment of centrifugal load using lever adjustment assembly, in addition, by changing the polarity of magnet on magnetic guide base, realize the intermittent adjustment between each centrifugal load in rotation of centrifugal regulation unit, enhance centrifugal effect, more truly simulate non-stationary excitation in actual working condition.

Description

Technical Field

[0001] This invention belongs to the field of centrifugal testing technology, specifically a non-contact adjustable centrifugal load fatigue testing device. Background Technology

[0002] In the research and development and verification of high-speed rotating machinery such as aero-engines, gas turbines, and centrifugal compressors, fatigue life testing of key components (such as blades, impellers, rotor disks, and shafts) under centrifugal loads is an essential step. Traditional techniques involve directly mounting counterweights on the rotating shaft and using the centrifugal force generated by rotation as the load. However, this method has the drawback that the centrifugal force is coupled with the rotational speed, making it impossible to independently adjust the load magnitude. While some testing equipment uses electromagnets to apply non-contact radial forces to rotating components, conventional electromagnetic or mechanical loading can only generate continuous or slowly varying loads, making it difficult to simulate the complex load spectra commonly encountered in actual operating conditions, such as periodic impacts, instantaneous overloads, and non-stationary excitations. Therefore, it is necessary to provide a non-contact, adjustable centrifugal load fatigue testing device to address the problems mentioned in the background. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution: a non-contact adjustable centrifugal load fatigue testing device, comprising: The test fixture is configured in an L-shape. A mounting bracket is fixed to the test frame, and two bearing seats are vertically distributed on the mounting bracket. The main shaft is vertically connected between the two bearing seats; A centrifugal adjustment unit is rotatably mounted on the fixed frame, and the upper end of the main shaft is connected to the centrifugal adjustment unit; A drive unit is mounted on the test frame, and the drive unit is connected to the lower end of the main shaft via a transmission belt. The coupling is fixed at the upper end of the centrifugal adjustment unit.

[0004] Furthermore, as a preferred embodiment, the coupling is detachably mounted with a clamp, and the part to be tested is fixed outside the mounting clamp.

[0005] Furthermore, preferably, the centrifugation adjustment unit includes: A centrifugal disc has a ring fixed at its center and is fixed to the main shaft through the ring. The mounting cavity is fan-shaped and located inside the centrifuge plate; The lever adjustment assembly is provided in multiple ways, and each lever adjustment assembly is radially arranged and evenly distributed in the mounting cavity; Centrifugal loads are equidistantly mounted on each of the aforementioned lever adjustment assemblies; A sliding shaft is coaxially slidably connected inside the main shaft, and the upper end of the sliding shaft is slidably connected through the centrifuge disc; The inner sleeve is coaxially and slidably disposed within the coupling, and the upper end of the sliding shaft is rotatably connected to the inner sleeve; A hydraulic cylinder is vertically connected to the bottom of the test frame, and the telescopic end of the hydraulic cylinder is fixed to the lower end of the sliding shaft; The magnetic base is fixed on the mounting frame and located below the centrifugal disc.

[0006] Furthermore, preferably, the central angle of the sector of the mounting cavity is less than 90°.

[0007] Furthermore, preferably, the lever adjustment assembly includes: A guide shaft is vertically arranged inside the centrifuge disc, and a rotating shaft body is rotatably connected inside the guide shaft. A lever shaft, one end of which is rotatably connected to the inner sleeve, and the other end of which slides through the rotating shaft body; A support spring is sleeved on the lever shaft. Multiple centrifugal loads are provided, all of which are movably sleeved on the lever shaft, and the support spring and the centrifugal loads are distributed alternately.

[0008] Furthermore, as a preferred embodiment, the guide shaft is vertically slidably connected to the centrifugal disc, and pressure blocks are symmetrically embedded in the centrifugal disc below the guide shaft. A magnetic shaft is installed between the pressure blocks, and the upper end of the magnetic shaft is connected to the guide shaft. The magnetic base has multiple magnets distributed around its inner circumference, and the magnetic axis is located directly above the corresponding magnet.

[0009] Furthermore, as a preferred embodiment, each of the pressure blocks is connected to a compression spring on one side, and the contact surface between the magnetic shaft and the two pressure blocks is set as an inclined structure.

[0010] Furthermore, as a preferred embodiment, a positioning pressure plate is slidably connected to the lever shaft, and a pressure roller is rotatably connected above the inner wall of the mounting cavity. The positioning pressure plate rolls into contact with the pressure roller as the lever shaft deflects.

[0011] Furthermore, as a preferred embodiment, the magnetic base has multiple cavities evenly distributed around its inner circumference, and each cavity is rotatably connected to a connecting shaft, with the magnet fixed on the connecting shaft. A rack is slidably connected inside the cavity, and a driven tooth is fixed on the connecting shaft, with the rack meshing with the driven tooth; A fine-tuning telescopic rod is fixed inside the cavity below the rack, and one end of the fine-tuning telescopic rod is connected to the rack.

[0012] Furthermore, as a preferred embodiment, the magnet repels the magnetic axis of the same polarity or attracts the magnetic axis of opposite polarity during the adjustment of rotation with the connecting shaft.

[0013] Compared with the prior art, the beneficial effects of the present invention are: In this invention, the centrifugal adjustment unit is equipped with a centrifugal load through multiple lever adjustment components, which enables non-contact continuous adjustment of the centrifugal load during the rotation of the main shaft. A magnetic guide seat is also provided on the fixed frame, and multiple rotatable and adjustable magnets are distributed in the magnetic guide seat. The magnets repel like poles or attract unlike poles with the magnetic axes in the lever adjustment components. Thus, by changing the polarity of the magnets, the centrifugal load of each centrifugal load can be intermittently adjusted during the rotation of the centrifugal adjustment unit, thereby enhancing the centrifugal effect. That is, when the centrifugal load suddenly moves outward within a specific angular range, an instantaneous centrifugal force peak is generated, which more realistically simulates the non-steady excitation in actual working conditions. In addition, the multiple magnets can be combined and adjusted to achieve non-uniform centrifugal load loading. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the centrifugal adjustment unit in this invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the mounting cavity in this invention; Figure 4 This is a schematic diagram of the lever adjustment component in this invention; Figure 5 This is a schematic diagram of the magnet structure in this invention; Figure 6 This is a schematic diagram of the structure of the magnetic base in this invention; In the diagram: 1. Test frame; 11. Fixing frame; 12. Main shaft; 13. With drive device; 14. Bearing seat; 15. Coupling; 2. Centrifugal adjustment unit; 21. Centrifugal disc; 22. Ring sleeve; 23. Mounting cavity; 24. Centrifugal load; 25. Sliding shaft; 26. Inner sleeve; 27. Hydraulic cylinder; 3. Lever adjustment assembly; 31. Guide shaft; 32. Rotating shaft body; 33. Lever shaft; 34. Support spring; 35. Pressure block; 36. Magnetic shaft; 37. Positioning pressure plate; 38. Pressure roller; 4. Magnetic guide seat; 41. Magnet; 42. Cavity; 43. Rack; 44. Driven gear; 45. Fine-tuning telescopic rod. Detailed Implementation

[0015] Please see Figures 1-6 In this embodiment of the invention, a non-contact adjustable centrifugal load fatigue testing device includes: Test frame 1 is configured as an L-shaped structure with anchor bolt mounting holes at the bottom for fixing to the test foundation platform; A fixing frame 11 is fixed on the test frame 1, and two bearing seats 14 are vertically distributed on the fixing frame 11; The main shaft 12 is vertically connected between the two bearing seats 14; Centrifugal adjustment unit 2 is rotatably mounted on the fixed frame 11. The upper end of the main shaft 12 is connected to the centrifugal adjustment unit 2, and the rotation axis of the centrifugal adjustment unit 2 is collinear with the main shaft 12. A drive device 13 is installed on the test frame 1. The drive device 13 is connected to the lower end of the main shaft 12 via a transmission belt. The drive device 13 includes a drive motor, a drive pulley, a transmission belt, and a tensioning mechanism. The tensioning mechanism is a spiral pressing type or an eccentric wheel type, used to adjust the preload of the transmission belt. A protective cover is provided around the drive device 13. The coupling 15 is fixed at the upper end of the centrifugal adjustment unit 2.

[0016] In this embodiment, the coupling 15 is detachably mounted with a clamp, and the part to be tested is fixed outside the mounting clamp. The part to be tested (such as blades, impellers, rotor disks, etc.) can be fixed to the outer circular surface of the mounting clamp by a special fixture or screws. The mounting clamp can be replaced according to the interface size of different parts to be tested.

[0017] In a preferred embodiment, the centrifugation adjustment unit 2 includes: The centrifugal disc 21 is a rotating disc structure with a ring 22 fixed at its center. The ring 22 is fixed to the main shaft 12. The ring 22 can be connected and fixed to the main shaft 12 by a threaded connection. The mounting cavity 23 is fan-shaped and located inside the centrifugal disc 21; There are multiple lever adjustment components 3, and each lever adjustment component 3 is radially and evenly distributed within the mounting cavity 23; Centrifugal load 24 is equidistantly mounted on each of the lever adjustment components 3. The lever adjustment components 3 can achieve continuous radial adjustment of the centrifugal load 24 under adjustment, so that it is closer to or further away from the center of rotation. The sliding shaft 25 is coaxially slidably connected inside the main shaft 12. The upper end of the sliding shaft 25 is slidably connected through the centrifugal disc 21. The sliding shaft 25 does not rotate synchronously with the main shaft 12, but only makes axial adjustment relative to the fixed frame 11. The inner sleeve 26 is coaxially and slidably disposed within the coupling 15, and the upper end of the sliding shaft 25 is rotatably connected to the inner sleeve 26; A hydraulic cylinder 27 is vertically connected to the bottom of the test frame 1. The telescopic end of the hydraulic cylinder 27 is fixed to the sliding shaft 25 and is used to drive the sliding shaft 25 to slide up and down. The magnetic base 4 is fixed on the fixed frame 11 and located below the centrifugal disc 21.

[0018] In this embodiment, the central angle of the sector of the mounting cavity 23 is less than 90°.

[0019] In this embodiment, the lever adjustment component 3 includes: A guide shaft 31 is vertically arranged inside the centrifugal disc 21, and a rotating shaft body 32 is rotatably connected inside the guide shaft 31. The lever shaft 33 has one end rotatably connected to the inner sleeve 26, and the other end slides through the rotating shaft body 32; A support spring 34 is sleeved on the lever shaft 33. Multiple centrifugal loads 24 are provided, and each centrifugal load 24 is movably sleeved on the lever shaft 33. The support spring 34 and the centrifugal loads 24 are staggered. Specifically, during the test, the part to be tested is fixed on the mounting sleeve by a special fixture. The main shaft 12 is driven to rotate at high speed by the drive device 13. During the rotation, the sliding shaft 25 moves axially downward under the extension and retraction adjustment of the hydraulic cylinder 27. At this time, each centrifugal load 24 can gradually move away from the center under the adjustment of the lever shaft 33, so as to realize the continuous change of the radial position of the centrifugal load 24, avoiding the load jump caused by traditional mechanical graded adjustment (such as pin pulling and gear shifting).

[0020] In this embodiment, the guide shaft 31 is vertically slidably connected to the centrifugal disk 21, and pressure blocks 35 are symmetrically embedded in the centrifugal disk 21 below the guide shaft 31. A magnetic shaft 36 is installed between the pressure blocks 35, and the upper end of the magnetic shaft 36 is connected to the guide shaft 31. Multiple magnets 41 are distributed around the inner circumference of the magnetic base 4, and the magnetic shaft 36 is located directly above the corresponding magnet 41. This arrangement allows for vertical adjustment of the guide shaft 31 by means of the magnetic repulsion or attraction of the magnetic field of the magnet 41 on the magnetic shaft 36. This, in turn, allows for further adjustment of the centrifugal load 24 by changing the position of the lever fulcrum, thus enabling auxiliary adjustment of the centrifugal load 24.

[0021] In a preferred embodiment, each of the pressure blocks 35 is connected to a compression spring on one side, and the contact surface between the magnetic shaft 36 and the two pressure blocks 35 is set as an inclined structure. In the natural state, the two compression springs use their spring force to press the pressure blocks 35 toward the magnetic shaft 36, and the magnetic shaft 36 is in the lowest position in space due to the pressure of the two pressure blocks 35.

[0022] In this embodiment, a positioning pressure plate 37 is slidably connected to the lever shaft 33, and a pressure roller 38 is rotatably connected above the inner wall of the mounting cavity 23. The positioning pressure plate 37 rolls and contacts the pressure roller 38 as the lever shaft 33 deflects. When the magnetic shaft 36 is at its lowest position due to the squeezing action of the two pressure blocks 35, one end of the lever shaft 33 radially adjusts the centrifugal load 24 as the inner sleeve 26 adjusts axially. At this time, the positioning pressure plate 37 on the lever shaft 33 always remains in contact with the pressure roller 38. When the lever shaft 33 adjusts the centrifugal load 24 away from the center, and the magnetic shaft 36 pushes the guide shaft 31 upward, the positioning pressure plate 37 on the lever shaft 33 can contact the pressure roller 38 as the lever shaft 33 swings. The pressure roller 38 axially pushes the centrifugal load 24 on the lever shaft 33, causing each centrifugal load 24 to move towards the end of the lever shaft 33, further increasing the instantaneous centrifugal force, thereby simulating transient high-energy excitations such as instantaneous overload and non-steady vibration.

[0023] In this embodiment, the magnetic base 4 has a plurality of cavities 42 evenly distributed around its inner circumference, and each cavity 42 is rotatably connected to a connecting shaft, and the magnet 41 is fixed on the connecting shaft. A rack 43 is slidably connected inside the cavity 42, and a driven tooth 44 is fixed on the connecting shaft. The rack 43 meshes with the driven tooth 44. A fine-tuning telescopic rod 45 is fixed inside the cavity 42 below the rack 43. One end of the fine-tuning telescopic rod 45 is connected to the rack 43. With this configuration, the fine-tuning telescopic rod 45 is driven by the rack 43 to rotate the driven tooth 44 in both directions during telescopic adjustment, thereby achieving the effect of flipping the magnet 41 on both sides and changing the polarity of the magnet 41.

[0024] In this embodiment, the magnet 41 repels the magnetic shaft 36 with the same polarity or attracts the magnetic shaft 36 with opposite polarity during the rotation adjustment with the connecting shaft. Specifically, during the conventional centrifugal force test, each magnet 41 can maintain an attraction with the magnetic shaft 36 with opposite polarity under adjustment. At this time, the magnetic shaft 36 remains stationary when passing each magnet 41 as the centrifugal disk 21 rotates. In this way, the continuous adjustment of the centrifugal load 24 can be achieved by only the lever adjustment component 3. In the simulation of instantaneous overload of centrifugal load, by changing the polarity of one or more adjacent magnets 41, making them repel the magnetic shaft 36, when the magnetic shaft 36 rotates with the centrifugal disk 21 and passes the corresponding magnet 41, the magnet 41 can repel the magnetic shaft 36 and push the magnetic shaft 36 axially upward. At this time, the lever fulcrum in the lever adjustment assembly 3 is relatively adjusted, causing the lever shaft 33 to swing. The centrifugal load 24 on the lever shaft 33 moves further away from the center. In addition, the positioning pressure plate 37 on the lever shaft 33 can contact the pressure roller 38 and further push each centrifugal load 24 away from the center. The load 24 moves toward the end of the lever shaft 33, and the centrifugal force is instantly enhanced. By adjusting the polarity of each magnet 41, the centrifugal disk 21 is precisely controlled to generate a corresponding number of transient adjustments of the centrifugal load 24 at a specific angle, generating instantaneous and large-amplitude centrifugal force overload, simulating more realistic sudden overload events (such as surge, unbalanced force after blade breakage). This device can flexibly combine conventional centrifugal force (lever adjustment) with instantaneous overload (magnetic trigger secondary enhancement) to more realistically simulate the composite load spectrum in the actual service environment, significantly improving the fatigue testing device's ability to simulate real complex load spectra.

[0025] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A non-contact adjustable centrifugal load fatigue testing device, characterized in that, It includes: Test fixture (1), which is configured as an L-shaped structure; A fixing frame (11) is fixed on the test frame (1), and two bearing seats (14) are vertically distributed on the fixing frame (11). The main shaft (12) is vertically connected between the two bearing seats (14); Centrifugal adjustment unit (2) is rotatably mounted on the fixed frame (11), and the upper end of the main shaft (12) is connected to the centrifugal adjustment unit (2); A drive device (13) is installed on the test frame (1), and the drive device (13) is connected to the lower end of the main shaft (12) via a transmission belt. The coupling (15) is fixed at the upper end of the centrifugal adjustment unit (2).

2. The fatigue testing device for non-contact adjustable centrifugal load according to claim 1, characterized in that, The coupling (15) is detachably mounted with a clamp, and the part to be tested is fixed outside the mounting clamp.

3. The fatigue testing device for non-contact adjustable centrifugal load according to claim 1, characterized in that: The centrifugation adjustment unit (2) includes: Centrifugal disc (21) has a ring (22) fixed at its center and is fixed to the main shaft (12) through the ring (22); The mounting cavity (23) is fan-shaped and located inside the centrifuge plate (21); There are multiple lever adjustment components (3), each of which is radially arranged and evenly distributed within the mounting cavity (23); Centrifugal loads (24) are equidistantly mounted on each of the lever adjustment assemblies (3); A sliding shaft (25) is coaxially slidably connected inside the main shaft (12), and the upper end of the sliding shaft (25) is slidably connected through the centrifugal disc (21); The inner sleeve (26) is coaxially slidably disposed inside the coupling (15), and the upper end of the sliding shaft (25) is rotatably connected to the inner sleeve (26); A hydraulic cylinder (27) is vertically connected to the lower part of the test frame (1), and the telescopic end of the hydraulic cylinder (27) is fixed to the lower end of the sliding shaft (25); The magnetic base (4) is fixed on the fixed frame (11) and located below the centrifugal disc (21).

4. The fatigue testing device for non-contact adjustable centrifugal load according to claim 3, characterized in that: The central angle of the sector of the mounting cavity (23) is less than 90°.

5. The fatigue testing device for non-contact adjustable centrifugal load according to claim 3, characterized in that, The lever adjustment component (3) includes: A guide shaft (31) is vertically arranged inside the centrifugal disc (21), and a rotating shaft body (32) is rotatably connected inside the guide shaft (31). A lever shaft (33) has one end rotatably connected to the inner sleeve (26) and the other end sliding through the rotating shaft body (32). A support spring (34) is sleeved on the lever shaft (33). Multiple centrifugal loads (24) are provided, and all centrifugal loads (24) are movably sleeved on the lever shaft (33). The support spring (34) and the centrifugal loads (24) are staggered.

6. The fatigue testing device for non-contact adjustable centrifugal load according to claim 5, characterized in that: The guide shaft (31) is vertically slidably connected to the centrifugal disc (21), and pressure blocks (35) are symmetrically embedded in the centrifugal disc (21) below the guide shaft (31). A magnetic shaft (36) is installed between the pressure blocks (35), and the upper end of the magnetic shaft (36) is connected to the guide shaft (31). The magnetic base (4) has multiple magnets (41) distributed around its inner circumference, and the magnetic axis (36) is located directly above the corresponding magnet (41).

7. The fatigue testing device for non-contact adjustable centrifugal load according to claim 6, characterized in that: Each of the pressure blocks (35) is connected to a compression spring on one side, and the contact surface between the magnetic shaft (36) and the two pressure blocks (35) is set as an inclined structure.

8. The fatigue testing device for non-contact adjustable centrifugal load according to claim 6, characterized in that: A positioning pressure plate (37) is slidably connected to the lever shaft (33), and a pressure roller (38) is rotatably connected above the inner wall of the mounting cavity (23). The positioning pressure plate (37) rolls and contacts the pressure roller (38) as the lever shaft (33) deflects.

9. The fatigue testing device for non-contact adjustable centrifugal load according to claim 7, characterized in that: The magnetic base (4) has multiple cavities (42) evenly distributed around its inner circumference. Each cavity (42) is rotatably connected to a connecting shaft, and the magnet (41) is fixed on the connecting shaft. A rack (43) is slidably connected inside the cavity (42), and a driven tooth (44) is fixed on the connecting shaft. The rack (43) meshes with the driven tooth (44). A fine-tuning telescopic rod (45) is fixed inside the cavity (42) below the rack (43), and one end of the fine-tuning telescopic rod (45) is connected to the rack (43).

10. A fatigue testing device for non-contact adjustable centrifugal load according to claim 9, characterized in that: The magnet (41) repels the magnetic shaft (36) or attracts the magnetic shaft (36) with the same polarity during the adjustment of the rotation with the connecting shaft.

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