Blade test fixture

Abstract

A kind of blade test fixture is used to simulate the assembly pre-torsion of blade crown.The blade crown of blade has first extrusion surface and second extrusion surface;The blade test fixture includes blade root clamping assembly and blade crown clamping assembly;The blade root clamping assembly is configured to fix the blade root of blade;The blade crown clamping assembly includes first clamping jaw, second clamping jaw slot and second clamping jaw, the second clamping jaw slot is fixed relative to the first clamping jaw, the second clamping jaw slot and the first clamping jaw are synchronously rotatably arranged, the second clamping jaw is used to insert the second clamping jaw slot, to position and limit the first clamping jaw and the second clamping jaw in clamping position, in the clamping position, the first clamping surface of the first clamping jaw is configured to be inclined to the first rotation direction relative to the first extrusion surface, the second clamping surface of the second clamping jaw is configured to be inclined to the first rotation direction relative to the second extrusion surface, so that when the first clamping surface abuts the first extrusion surface and the second clamping surface abuts the second extrusion surface, the blade crown rotates to the first rotation direction.

Description

Technical Field

[0001] This invention relates to the field of aero-engine testing, and more specifically to a blade testing fixture. Background Technology

[0002] Turbine blade crowns generally serve two purposes: First, they improve turbine performance. The radial clearance of a turbine changes during operation, and whether it operates at its optimal position directly affects turbine performance. Without experience, to prevent transient mechanical wear, the radial clearance is often chosen to be too large, resulting in excessive radial leakage losses in steady state. With a crown, the gap between the serrations on the crown and the honeycomb outer ring can be reduced, allowing for honeycomb wear and thus reducing leakage losses. Second, they alter the vibration characteristics of the turbine blade. Adjacent crowns contact each other through the crown contact surface, essentially creating a fulcrum at the blade tip. By appropriately setting the assembly pre-tightening between adjacent crown contact surfaces, the vibration characteristics of the blade during operation can be improved. Choosing a reasonable assembly pre-tightening for the crown contact surface is crucial. If the assembly pre-tightening is too small, gaps appear between adjacent crown contact surfaces, failing to provide dry friction damping and vibration reduction, while also causing gas leakage losses. If the pre-tightening is too large, excessive compressive stress occurs between adjacent crown contact surfaces, affecting blade life. Therefore, in blade crown design, the key is to ensure that adjacent crown contact surfaces maintain a reasonable pre-twist during blade operation to improve turbine efficiency and reduce vibration. Thus, in turbine blade crown compression wear vibration fatigue tests, it is necessary to simulate the pre-twist of the crown assembly using fixtures and to simulate different assembly tightnesses at the crown contact surfaces. Summary of the Invention

[0003] The purpose of this invention is to provide a blade test fixture for simulating the pre-twist of blade crown assembly.

[0004] The blade crown has a first compression surface and a second compression surface. According to an embodiment of the present invention, the blade test fixture includes a blade root clamping assembly and a blade crown clamping assembly; the blade root clamping assembly is configured to fix the blade root; the blade crown clamping assembly includes a first clamp, a second clamp groove, and a second clamp, the second clamp groove being fixed relative to the first clamp, the second clamp groove and the first clamp being rotatably disposed, the second clamp being used to insert into the second clamp groove to position and limit the first clamp and the second clamp in a clamping position, in the clamping position, the first clamping surface of the first clamp is configured to be inclined relative to the first compression surface in a first rotation direction, and the second clamping surface of the second clamp is configured to be inclined relative to the second compression surface in the first rotation direction, so that when the first clamping surface abuts against the first compression surface and the second clamping surface abuts against the second compression surface, the blade crown rotates in the first rotation direction.

[0005] In one or more embodiments, the shape and size of the second gripper groove are the same as those of the second gripper.

[0006] In one or more embodiments, the second gripper groove and the first gripper are disposed on a turntable, the turntable being rotatably disposed on a base, and the second gripper being used to fixally connect to the base to limit the first gripper and the second gripper to the clamping position.

[0007] In one or more embodiments, the optical axis of the turntable is inserted into the optical hole of the base.

[0008] In one or more embodiments, the threaded hole of the second gripper and the threaded hole of the base are threadedly connected to a bolt, the bolt pressing and fixing the second gripper to the base.

[0009] In one or more embodiments, the second gripper groove has a fan-shaped profile, and the second gripper has a fan-shaped profile.

[0010] In one or more embodiments, the first clamping surface is configured to be inclined at a first angle relative to the first extrusion surface in the first rotation direction, and the second clamping surface is configured to be inclined at the first angle relative to the second extrusion surface in the first rotation direction.

[0011] In one or more embodiments, the first clamping surface and the second clamping surface are parallel to each other.

[0012] In one or more embodiments, the first clamping surface and the second clamping surface are provided with gasket grooves, the gasket grooves are provided with replaceable gaskets, the replaceable gaskets protrude from the first clamping surface and the second clamping surface respectively to abut against the first pressing surface and the second pressing surface respectively, the replaceable gaskets include multiple sets, and the thickness of each set of replaceable gaskets protruding from the first clamping surface and the second clamping surface is different.

[0013] In one or more embodiments, the leaf root clamping assembly includes a tenon for receiving a tenon of the leaf root, and a bolt protruding from the bottom of the tenon to push the tenon against the tenon.

[0014] The embodiments of the present invention have at least the following beneficial effects:

[0015] In the clamping position, the first clamping surface of the first jaw is inclined in the first rotation direction relative to the first extrusion surface of the untwisted blade crown, and the second clamping surface of the second jaw is inclined in the first rotation direction relative to the second extrusion surface of the untwisted blade crown. The first clamping surface abuts against the first extrusion surface, and the blade crown tends to rotate in the first rotation direction to reduce the gap. The second clamping surface abuts against the second extrusion surface, and the blade crown tends to rotate in the first rotation direction to reduce the gap. Thus, the blade crown is driven to rotate in the first rotation direction, and the blade crown twists relative to the blade root, simulating the pre-twist of the blade crown assembly. Attached Figure Description

[0016] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0017] Figure 1 An oblique view of the blade being held in place by the blade testing fixture;

[0018] Figure 2 A top view of the leaf root clamping assembly clamping the leaf root;

[0019] Figure 3 for Figure 2 A magnified view of a portion of the image;

[0020] Figure 4 This is a perspective view of the base.

[0021] Figure 5 An oblique view of the turntable, the first gripper, and the second gripper groove;

[0022] Figure 6 This is a perspective view of the second gripper;

[0023] Figure 7 A front view of the leaf crown clamping assembly holding the leaf crown;

[0024] Figure 8 A schematic diagram illustrating the principle of the blade clamping assembly for clamping and twisting the blade crown;

[0025] Figure 9 A schematic diagram illustrating the principle of the blade clamping assembly for clamping and twisting the blade crown.

[0026] Figure label:

[0027] 1-Leaf root clamping assembly;

[0028] 2-Cover clamping assembly;

[0029] 3-blade;

[0030] 4-Leaf roots;

[0031] 5-Leaf crown;

[0032] 6-First seat;

[0033] 7-First bolt;

[0034] 8-Tongue and groove;

[0035] 9-Tenon;

[0036] 10 - Second bolt;

[0037] 11-Tenon working surface;

[0038] 12-Tongue and groove working surface;

[0039] 13-First extrusion surface;

[0040] 14 - Second extrusion surface;

[0041] 15 - First gripper;

[0042] 16-Second gripper groove;

[0043] 17 - Second gripper;

[0044] 18-Turntable;

[0045] 19-Second seat;

[0046] 20-optical axis;

[0047] 21-Aperture;

[0048] 22-Turntable slot;

[0049] 23 - First chamfered surface;

[0050] 24 - Second chamfered surface;

[0051] 25 - Third bolt;

[0052] 26 - Second threaded hole;

[0053] 27 - Third threaded hole;

[0054] 28 - First clamping surface;

[0055] 29 - Second clamping surface;

[0056] 30 - First direction of rotation;

[0057] 31 - Fourth bolt;

[0058] 32-Gasket Groove;

[0059] 33 - Replaceable gasket. Detailed Implementation

[0060] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to explain the invention and not to limit it. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the invention without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, the invention is intended to cover these modifications and variations that fall within the scope of the appended claims and their equivalents.

[0061] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention.

[0062] The terms “first”, “second”, etc., are used interchangeably to distinguish one feature from another and are not intended to indicate that each feature must be located in the position shown in the figure in each embodiment.

[0063] like Figure 1 As shown, the blade testing fixture includes a leaf root clamping assembly 1 and a leaf crown clamping assembly 2. The leaf root clamping assembly 1 clamps and fixes the leaf root 4 of the blade 3. Figure 2 and Figure 3 (As shown in the image). The leaf crown clamping assembly 2 clamps and fixes the leaf crown 5 of the blade 3.

[0064] like Figures 1 to 3 As shown, the blade root clamping assembly 1 may be equipped with a first base 6. The first base 6 may be fixed to a test bench, such as a vibration table for vibration fatigue testing, by a first bolt 7. The first base 6 may be equipped with a tenon 8, which accommodates the tenon 9 of the blade root 4, with the tenon 9 located within the tenon 8. The first base 6 may be provided with a first threaded hole at the bottom of the tenon 8, and a second bolt 10 is threadedly connected to the first threaded hole. The screw of the second bolt 10 protrudes from the bottom of the tenon 8 and enters the tenon 8. The screw of the second bolt 10 pushes against the bottom surface of the tenon 9, causing the tenon 9 to adhere to the tenon 8. The working surface 11 of the tenon adheres tightly to the working surface 12 of the tenon, and the tenon 9 is completely clamped and fixed.

[0065] like Figure 7 As shown, the leaf crown 5 has a first pressing surface 13 and a second pressing surface 14, which are located on the two circumferential edges of the leaf crown 5, respectively, and are used to contact, press, and rub against the pressing surfaces of the circumferentially adjacent leaf crowns. The leaf crown 5 may be a serrated leaf crown, with the first pressing surface 13 and the second pressing surface 14 provided by the short edges of the serrations located on the circumferential edges.

[0066] like Figures 5 to 7 As shown, the leaf crown clamping assembly 2 includes a first clamp 15, a second clamp groove 16, and a second clamp 17. Figure 5 As shown, the second gripper groove 16 is fixed relative to the first gripper 15, and the second gripper groove 16 and the first gripper 15 are rotatably arranged. The second gripper groove 16 and the first gripper 15 can be disposed on a turntable 18, with the first gripper 15 protruding from the surface of the turntable 18 and the second gripper groove 16 recessed from the surface of the turntable 18. The turntable 18 is rotatably disposed on... Figure 4 The second seat 19 shown can be equipped with an optical axis 20 on the turntable 18, further combining... Figure 4 The second base 19 may be provided with an optical aperture 21, and the optical axis 20 is inserted into the optical aperture 21 and can slide and rotate relative to the optical aperture 21. The second base 19 may also be provided with a turntable groove 22, in which the turntable 18 rotates.

[0067] like Figures 5 to 7 As shown, the second gripper 17 is used to insert into the second gripper groove 16 to position and limit the first gripper 15 and the second gripper 17 in the clamping position. The shape and size of the second gripper groove 16 can be the same as the second gripper 17. When the second gripper 17 is inserted into the second gripper groove 16, the turntable 18 rotates to make the second gripper groove 16 and the second gripper 17 completely aligned, thereby positioning the first gripper 15 and the second gripper 17 in the clamping position. The second gripper groove 16 can have a fan-shaped profile, and the second gripper 17 can have a fan-shaped profile. When the second gripper 17 is inserted into the second gripper groove 16, the two straight sidewalls of the second gripper 17 push the two straight sidewalls of the second gripper groove 16, and the two straight sidewalls of the second gripper 17 slide relative to the two straight sidewalls of the second gripper groove 16, thereby making the second gripper groove 16 and the second gripper 17 aligned and inserted.

[0068] like Figure 5 and Figure 6 As shown, the second gripper groove 16 can be provided with a first chamfered surface 23 on the outer edge of the bottom wall, and the second gripper 17 can be provided with a second chamfered surface 24 at the root of the bottom wall to reduce stress concentration. The second gripper 17 is inserted into the second gripper groove 16, and the second chamfered surface 24 is attached to the first chamfered surface 23 to further position the second gripper 17 and the second gripper groove 16 to be completely aligned, thereby positioning the first gripper 15 and the second gripper 17 in the clamping position.

[0069] like Figure 7 As shown, in the clamping position, the second gripper 17 is fixedly connected to the second base 19, the second gripper 17 is limited, the second gripper 17 is inserted into the second gripper groove 16 to limit the position of the turntable 18, the first gripper 15 is limited, and the first gripper 15 and the second gripper 17 are thus limited in the clamping position. The second gripper 17 can be fixed to the second base 19 by a third bolt 25, the third bolt 25 being threaded into the second threaded hole 26 of the second gripper 17. Figure 6 (as shown in the image), the third threaded hole 27 of the second seat 19 ( Figure 4(As shown in the diagram), the second gripper 17 is pressed and secured to the second base 19. After removing the third bolt 25, the second gripper 17 and the turntable 18 can be removed from the second base 19. Figure 1 As shown, the second seat 19 can be fixed to the test bench, such as the vibration table for vibration fatigue testing, by means of the fourth bolt 31.

[0070] Figure 8 and Figure 9 The principle of the leaf crown clamping assembly 2 clamping and twisting the leaf crown 5 is shown, wherein the first clamp 15, the second clamp 17 and the leaf crown 5 are shown in a simplified manner. Figure 8 In the middle, the first gripper 15 and the second gripper 17 are in the clamped position, the leaf crown 5 is in the untwisted position, and the second gripper 17 partially overlaps with the leaf crown 5, the outline of the overlapping part is shown by dashed lines. Figure 9 In the middle, the first gripper 15 and the second gripper 17 are in the clamping position, and the leaf crown 5 is in the twisted position after twisting.

[0071] like Figure 8 As shown, in the clamping position, the first clamping surface 28 of the first jaw 15 is inclined at a first angle relative to the first pressing surface 13 of the untwisted blade crown 5 in the first rotation direction 30, and the second clamping surface 29 of the second jaw 17 is inclined at a second angle relative to the second pressing surface 14 of the untwisted blade crown 5 in the first rotation direction 30. Further combined... Figure 9 During the process of the second clamping jaw 17 being inserted into the second clamping jaw groove 16 to clamp the blade crown 5 with the first clamping jaw 15, the first clamping surface 28 abuts against the first pressing surface 13, and the blade crown 5 tends to rotate in the first rotation direction 30 to reduce the first angle interval. The second clamping surface 29 abuts against the second pressing surface 14, and the blade crown 5 tends to rotate in the first rotation direction 30 to reduce the second angle interval. Thus, the blade crown 5 is driven to rotate in the first rotation direction 30, and the blade crown 5 twists relative to the blade root 4, simulating the pre-twist of the blade crown 5 during assembly. Compared with the blade crown fixture that clamps first and then rotates to load, it is closer to the pre-twist state of the blade crown 5 during assembly, with better simulation and improved accuracy of test results.

[0072] like Figure 8 As shown, in the clamping position, the first angle at which the first clamping surface 28 is inclined relative to the first pressing surface 13 in the first rotation direction 30 can be the same as the second angle at which the second clamping surface 29 is inclined relative to the second pressing surface 14 in the first rotation direction 30. The second clamping surface 29 is also inclined relative to the second pressing surface 14 in the first rotation direction 30 at the same first angle. Further combining... Figure 9During the process of the second clamping jaw 17 being inserted into the second clamping jaw groove 16 to clamp the blade crown 5 with the first clamping jaw 15, the blade crown 5 is driven to rotate in the first rotation direction 30. After the blade crown 5 rotates to the first angle, the first pressing surface 13 adheres to the first clamping surface 28, and the second pressing surface 14 adheres to the second clamping surface 29. The blade crown 5 stops rotating and adheres to the first clamping jaw 15 and the second clamping jaw 17, and is firmly clamped by the first clamping jaw 15 and the second clamping jaw 17.

[0073] like Figures 7 to 9 As shown, the first extrusion surface 13 and the second extrusion surface 14 can be parallel to each other. The first clamping surface 28 relative to the first extrusion surface 13 and the second clamping surface 29 relative to the second extrusion surface 14 can be tilted at the same angle in the first rotation direction 30. The first clamping surface 28 and the second clamping surface 29 can be parallel to each other.

[0074] The process of the above-mentioned leaf crown clamping assembly 2 clamping the leaf crown 5 is as follows: the first clamping surface 28 of the first clamping jaw 15 overlaps the first pressing surface 13 of the leaf crown 5, the second clamping jaw 17 is inserted into the second clamping jaw groove 16, as the second clamping jaw 17 is inserted, the turntable 18 and the first clamping jaw 15 on it rotate, and the second clamping surface 29 of the second clamping jaw 17 abuts against the second pressing surface 14 of the leaf crown 5, the leaf crown 5 is driven to rotate in the first rotation direction 30, finally, the first clamping jaw 15 on the turntable 18 rotates to the clamping position, the second clamping jaw 17 is inserted into the second clamping jaw groove 16 in the clamping position, the first pressing surface 13 is attached to the first clamping surface 28, the second pressing surface 14 is attached to the second clamping surface 29, and the leaf crown clamping assembly 2 clamps the leaf crown 5.

[0075] like Figure 5 and Figure 6As shown, the first clamping surface 28 and the second clamping surface 29 can be provided with a gasket groove 32. The gasket groove 32 can extend laterally from the ends of the first clamping jaw 15 and the second clamping jaw 17 to the first clamping surface 28 and the second clamping surface 29, respectively. The gasket groove 32 is provided with a replaceable gasket 33, which can be inserted into the gasket groove 32 in the direction of the arrow shown in the figure. The replaceable gasket 33 protrudes from the gasket groove 32 from the first clamping surface 28 and the second clamping surface 29. When the blade crown clamping assembly 2 clamps the blade crown 5, the replaceable gasket 33 of the first clamping jaw 15 abuts against the first pressing surface 13, and the replaceable gasket 33 of the second clamping jaw 17 abuts against the second pressing surface 14. The replaceable gasket 33 applies a pressing force to the first pressing surface 13 and the second pressing surface 14 to simulate the assembly tightness of the blade crown 5. The replaceable shims 33 include multiple sets, each set having a different thickness. The thickness of each set of replaceable shims 33 protruding from the first clamping surface 28 and the second clamping surface 29 is also different, resulting in different compressive forces applied by each set of replaceable shims 33 to the first pressing surface 13 and the second pressing surface 14. By replacing different sets of replaceable shims 33, different assembly tightnesses of the blade crown 5 can be simulated. Moreover, only different sets of replaceable shims 33 need to be replaced, without disassembling the blade crown clamping assembly 2, making the operation simple and convenient.

[0076] The first seat 6, the second seat 19, the second gripper 17, the turntable 18, and the first gripper 15 on it are all made of metal, such as stainless steel.

[0077] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention.

Claims

1. A blade testing fixture, wherein the blade crown has a first compression surface and a second compression surface, characterized in that, The blade testing fixture includes: A leaf root clamping assembly configured to secure the leaf root of the blade; and A leaf crown clamping assembly includes a first clamping jaw, a second clamping jaw groove, and a second clamping jaw. The second clamping jaw groove is fixed relative to the first clamping jaw. The second clamping jaw groove and the first clamping jaw are rotatably configured. The second clamping jaw is used to insert into the second clamping jaw groove to position and limit the first clamping jaw and the second clamping jaw in a clamping position. In the clamping position, the first clamping surface of the first clamping jaw is configured to be inclined relative to the first pressing surface in a first rotation direction, and the second clamping surface of the second clamping jaw is configured to be inclined relative to the second pressing surface in the first rotation direction. This is so that during the process of the second clamping jaw inserting into the second clamping jaw groove to the clamping position, the first clamping surface abuts against the first pressing surface to cause the leaf crown to rotate in the first rotation direction, and the second clamping surface abuts against the second pressing surface to cause the leaf crown to rotate in the first rotation direction, thereby driving the leaf crown to rotate in the first rotation direction.

2. The blade testing fixture according to claim 1, characterized in that: The shape and size of the second gripper groove are the same as those of the second gripper.

3. The blade testing fixture according to claim 2, characterized in that: The second gripper groove and the first gripper are disposed on the turntable, which is rotatably disposed on the base. The second gripper is used to fixally connect to the base to limit the first gripper and the second gripper to the clamping position.

4. The blade testing fixture according to claim 3, characterized in that: The optical axis of the turntable is inserted into the optical hole of the base.

5. The blade testing fixture according to claim 3, characterized in that: The threaded hole of the second gripper and the threaded hole of the base are connected by a bolt, which presses and fixes the second gripper to the base.

6. The blade testing fixture according to claim 2, characterized in that: The second gripper groove has a fan-shaped profile, and the second gripper has a fan-shaped profile.

7. The blade testing fixture according to claim 1, characterized in that: The first clamping surface is configured to be inclined at a first angle relative to the first extrusion surface in the first rotation direction, and the second clamping surface is configured to be inclined at the first angle relative to the second extrusion surface in the first rotation direction.

8. The blade testing fixture according to claim 7, characterized in that: The first clamping surface and the second clamping surface are parallel to each other.

9. The blade testing fixture according to claim 1, characterized in that: The first clamping surface and the second clamping surface are provided with gasket grooves, and the gasket grooves are provided with replaceable gaskets. The replaceable gaskets protrude from the first clamping surface and the second clamping surface respectively to abut against the first pressing surface and the second pressing surface respectively. The replaceable gaskets include multiple sets, and the thickness of each set of replaceable gaskets protruding from the first clamping surface and the second clamping surface is different.

10. The blade testing fixture according to claim 1, characterized in that: The leaf root clamping assembly includes a tenon for receiving a tenon of the leaf root, and a bolt protruding from the bottom of the tenon to push the tenon against the tenon.

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