A floating spline friction and wear test piece, test device and method

Abstract

This application discloses a floating spline friction and wear test piece, test device, and method, belonging to the field of aerospace technology. It includes an inner test piece and an outer test piece. The outer tooth surface of the outer test piece mates with the inner tooth surface of the inner test piece to form a spline pair. At the spline pair connection point, the end near the inner test piece is a positioning section one, and the end near the outer test piece is a positioning section two. A lubrication cavity is formed between the positioning sections one and two. Through the meshing of the spline tooth surfaces of the inner and outer test pieces, the change in the tooth surface friction coefficient is understood during the test, thereby allowing for accurate calculation of the wear amount.

Description

Technical Field

[0001] This application belongs to the field of aerospace technology, and specifically relates to a floating spline friction and wear test piece, test device and method. Background Technology

[0002] Floating spline pairs have advantages such as compact structure and high power transmission, and are widely used in aerospace transmission systems. However, during operation, misalignment causes the spline to bear additional bending moments, and uneven load distribution between spline teeth leads to spline wear, further affecting the spline's operational stability and service life. To analyze the wear of floating spline pairs under different operating conditions such as different materials, different heat treatments, different axial float amounts, different misalignment amounts, and different lubricants (greases), numerical simulation analysis, pin-disc friction and wear tests, or bench operation are commonly used.

[0003] Existing methods for analyzing the friction and wear of floating splines mainly employ numerical simulation, pin-disc friction and wear tests, or bench testing. Numerical simulation analysis primarily relies on the Archard modified model to calculate spline wear; however, this model neglects changes in the tooth surface friction coefficient, thus failing to accurately calculate wear variations. Pin-disc friction and wear tests cannot fully simulate the contact of the spline pair and do not accurately reflect its working conditions, resulting in inaccurate results. While bench testing can realistically simulate the spline's working conditions and yield accurate results, it is time-consuming and costly. Summary of the Invention

[0004] To address the aforementioned problems, this application provides a floating spline friction and wear testing device, comprising an inner test piece and an outer test piece; the outer tooth surface of the outer test piece and the inner tooth surface of the inner test piece mate to form a spline pair; The end of the spline joint closer to the inner test piece is called positioning section one, and the end of the spline joint closer to the outer test piece is called positioning section two; a lubrication cavity is formed between positioning section one and positioning section two in the spline joint.

[0005] This application provides a floating spline friction and wear testing device, including the aforementioned test piece body, mounting base, and support frame; the inner test piece of the test piece body is mounted on the mounting base; the support frame supports the outer test piece of the test piece body, and the first end of the support frame is mounted on the mounting base; a torque plate is installed between the second end of the support frame and the outer test piece. The end of the torque-adding disk away from the support frame is equipped with a loading cylinder; the outer edge of the torque-adding disk is fixedly connected to the outer edge of the loading cylinder; the inner edge of the torque-adding disk is fixedly connected to the outer test piece; the loading cylinder has an output end of servo cylinder one through a conversion connector; the two ends of the torque-adding disk are respectively connected to the output ends of servo cylinder two through conversion connectors.

[0006] Furthermore, the conversion connector includes a lifting lug; one end of the lifting lug is mounted on the loading cylinder or the torque plate, and the other end of the lifting lug is connected to either servo cylinder one or servo cylinder two in sequence via a spherical bearing and a fork-shaped component.

[0007] Furthermore, it also includes a base, on which the mounting bracket is disposed.

[0008] Furthermore, the mounting base is provided with an adjustment pad, and the support frame is mounted on the adjustment pad.

[0009] Furthermore, it also includes a bracket, which is semi-enclosed and positioned outside the mounting base and the test piece body; the fixed ends of both the first servo cylinder and the second servo cylinder are mounted on the bracket.

[0010] This application provides a method for testing the friction and wear of a floating spline, based on the aforementioned floating spline friction and wear testing apparatus, comprising: Mount the test specimen onto the test apparatus; Based on the working conditions of the test specimen, determine the torsional load T. M axial floating displacement S and main cycle count N; The applied force of the two servo cylinders is calculated based on the distance L between them. Apply loads to debug the system; The test specimen is subjected to periodic torque loading by adding a torsion disc; During the periodic torque loading process, the test piece body is axially reciprocated by the loading cylinder; The wear amount of the test piece is measured and analyzed to obtain the evaluation results of friction and wear performance.

[0011] Furthermore, loads are applied to debug the system, including: First, apply 40% of the target load to the test piece to eliminate the installation gap; Then, the torque loading channel and the displacement loading channel were debugged separately. Finally, multi-channel coordinated loading and joint debugging were performed, and loading accuracy was ensured by adjusting the controller parameters.

[0012] Furthermore, the test piece is subjected to periodic torque loading by adding a torsion plate, including: Execute the main loop N times; Each main loop consists of: loading in the first time period; a smaller loop in the second time period; and unloading in the third time period.

[0013] Furthermore, during the periodic torque loading process, the test piece body is axially reciprocated through the loading cylinder, including: During each main cycle, an axial reciprocating sliding displacement of ±S and a sliding frequency of H is applied to the test specimen body through the third loading channel.

[0014] Compared with the prior art, this application has the following advantages: 1. This application uses the spline tooth surfaces of the inner and outer test pieces to mesh, and understands the change in the tooth surface friction coefficient during the test, thereby accurately calculating the change in wear.

[0015] 2. This application uses a torsion disc, test piece body and loading cylinder for precise installation to simulate the real working conditions of floating splines under torsion and axial loads. The data is accurate and reliable, the cost is low, and it can meet the usage requirements of aviation floating splines.

[0016] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures pointed out in the description and the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A cross-sectional view of the test specimen in an embodiment of the present invention is shown.

[0019] Figure 2 A cross-sectional view of the experimental apparatus in an embodiment of the present invention is shown.

[0020] Figure 3 A schematic diagram of the experimental apparatus in an embodiment of the present invention is shown.

[0021] Figure 4 A diagram illustrating the torque loading process in an embodiment of the present invention is shown.

[0022] Figure 5 A flowchart of the experimental method in an embodiment of the present invention is shown.

[0023] In the diagram, 1. Base; 2. Mounting seat; 3. Adjusting shim; 4. Test piece body; 401. Inner test piece; 402. O-ring one; 403. Positioning section one; 404. Lubrication cavity; 405. Spline pair; 406. Positioning section two; 407. O-ring two; 408. Outer test piece; 5. Support frame; 6. Add a torsion plate; 7. Loading cylinder; 8. Lifting lug; 9. Bolt assembly; 10. Spherical bearing; 11. Fork-shaped part; 12. Servo cylinder one; 13. Connecting screw five; 14. Bracket; 15. Connecting screw four; 16. Connecting screw three; 17. Connecting screw two; 18. Connecting screw one; 19. Servo cylinder two. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] This application provides a floating spline friction and wear test specimen, with reference to... Figure 1 It includes an inner test piece 401 and an outer test piece 408; the outer tooth surface of the outer test piece 408 and the inner tooth surface of the inner test piece 401 are fitted together to form a spline pair 405; The end of the spline pair 405 near the inner test piece 401 is a positioning section 1 403, and the end of the spline pair 405 near the outer test piece 408 is a positioning section 2 406; a lubrication cavity 404 is formed between the spline pair 405 and the positioning section 1 403 and the positioning section 2 406.

[0026] The test specimen body 4 consists of an inner test specimen 401 and an outer test specimen 408. When designing the test specimen body 4, the requirements for materials, positioning sections, and heat treatment such as carburizing or nitriding of spline tooth surfaces, hardness requirements, surface treatment requirements (whether to spray carbides, plate hard chrome, etc.), side clearance requirements of spline pair 405, and lubrication method (grease or lubricating oil) should be clearly defined. The inner wall of the inner test specimen 401 has spline teeth, and the outer wall of the outer test specimen 408 has spline teeth. An O-ring 402 is provided near the positioning section 403 at the connection between the inner test specimen 401 and the outer test specimen 408. An O-ring 407 is provided near the positioning section 406 at the connection between the inner test specimen 401 and the outer test specimen 408.

[0027] This application uses the splined tooth surfaces of the inner test piece 401 and the outer test piece 408 to understand the changes in the tooth surface friction coefficient during the test, thereby enabling accurate calculation of the changes in wear.

[0028] This application proposes a floating spline friction and wear testing device, including the aforementioned test piece body 4, mounting base 2, and support frame 5; the inner test piece (401) of the test piece body 4 is mounted on the mounting base 2; the support frame 5 supports the outer test piece (408) of the test piece body 4, and the first end of the support frame 5 is mounted on the mounting base 2; a torsion plate 6 is installed between the second end of the support frame 5 and the outer test piece (408) of the test piece body 4; refer to Figure 2 The end of the torque-adding disk 6 away from the support frame 5 is equipped with a loading cylinder 7; the outer edge of the torque-adding disk 6 is fixedly connected to the outer edge of the loading cylinder 7; the inner edge of the torque-adding disk 6 is fixedly connected to the outer test piece (408) of the test piece body 4; the loading cylinder 7 has an output end of a servo cylinder 12 via a conversion connector; the two ends of the torque-adding disk 6 are respectively connected to the output ends of a servo cylinder 2 19 via conversion connectors.

[0029] The first end of the mounting base 2 and the test specimen body 4 is connected by connecting screw 18; the support frame 5 and the mounting base 2 are connected by connecting screw 27; the torsion plate 6 and the test specimen body 4 are connected by connecting screw 36; and the torsion plate 6 and the loading cylinder 7 are connected by connecting screw 45. The experimental device has a multi-channel coordinated loading control function, specifically including a first loading channel, a second loading channel, and a third loading channel; the working channels of the two servo cylinders 19 are the first and second loading channels, and the working channel of the servo cylinder 12 is the third loading channel; when applying torque loading, the servo cylinder 19 is activated to open the first and second loading channels; when applying sliding displacement loading, the servo cylinder 12 is activated to open the third loading channel.

[0030] When torque loading is applied, the extension and retraction drive conversion connector of the servo cylinder 219 generates a torque on the torque-applying disk 6, which then applies the torque to the test piece body 4.

[0031] During sliding displacement loading, the servo cylinder 12 extends and retracts to generate force on the loading cylinder 7, which in turn drives the test piece body 4 to perform precise reciprocating linear motion.

[0032] In one embodiment of this application, the conversion connector includes a lug 8; one end of the lug 8 is mounted on the loading cylinder 7, and the other end of the lug 8 is connected to the servo cylinder 12 in sequence through a spherical bearing 10 and a fork-shaped member 11.

[0033] The conversion connector includes a lug 8; one end of the lug 8 is mounted on the torque plate 6, and the other end of the lug 8 is connected to the servo cylinder 19 in sequence through a spherical bearing 10 and a fork-shaped part 11.

[0034] The lifting lug 8 fixes the cylinder bodies of servo cylinder 12 and servo cylinder 2 19, allowing them to swing; the lifting lug 8 and the fork-shaped part 11 are connected by bolt assembly 9; the fork-shaped part 11 of servo cylinder 2 19 converts linear force into eccentric force during torque loading, forming torque; the spherical bearing 10 in servo cylinder 2 19 connects the fork-shaped part 11 and the torque-adding disk 6, allowing rotation and swinging, eliminating motion interference; the fork-shaped part 11 and the spherical bearing 10 in servo cylinder 12 are designed to not restrict the movement of the torque-adding disk 6 during torque loading.

[0035] It also includes a base 1, and the mounting base 2 is disposed on the base 1.

[0036] An adjustment pad 3 is provided on the mounting base 2, and the support frame 5 is installed on the adjustment pad 3.

[0037] Adjustment shims 3 are set up for centering and adjustment to ensure that the geometric relationship between the test piece body 4, the loading cylinder 7 and the torsion plate 6 is precisely matched, and to ensure that the test piece body 4, the loading cylinder 7 and the torsion plate 6 are coaxial, so as to achieve high-precision assembly.

[0038] refer to Figure 3 It also includes a bracket 14, which is semi-enclosed and arranged outside the mounting base 2 and the test piece body 4; the fixed ends of the servo cylinder 12 and the servo cylinder 2 19 are both mounted on the bracket 14.

[0039] The bracket 14 surrounds the entire test piece body 4 and the loading cylinder 7, and maintains a certain distance between the servo cylinder 12 and the servo cylinder 2 19. The fixed ends of the servo cylinder 12 and the servo cylinder 2 19 are connected to the bracket 14 by connecting screw 5 13.

[0040] This application uses a torsion disc 6, test piece body 4 and loading cylinder 7 for precise installation and testing, which can simulate the real working conditions of floating splines under torsion and axial load. The data is accurate and reliable, the cost is low, and it can meet the usage requirements of aviation floating splines.

[0041] refer to Figure 5 This application proposes a floating spline friction and wear test method, based on the above-mentioned floating spline friction and wear test device, comprising: Install the test specimen body 4 onto the test device; Based on the four working conditions of the test specimen, the torsional load T is determined. M axial floating displacement S and main cycle count N; The applied force of the two servo cylinders 19 is calculated based on the distance L between them. Apply loads to debug the system; The test specimen body 4 is subjected to periodic torque loading by adding a torsion disc 6; During the periodic torque loading process, the test piece body 4 is axially reciprocated through the loading cylinder 7; The wear amount of the test specimen body 4 was measured and analyzed to obtain the evaluation results of friction and wear performance.

[0042] In one embodiment of this application, applying a load to debug the system includes: First, apply 40% of the target load to the test piece to eliminate the installation gap; Then, the torque loading channel and the displacement loading channel were debugged separately. Finally, multi-channel coordinated loading and joint debugging were performed, and loading accuracy was ensured by adjusting the controller parameters.

[0043] In one embodiment of this application, the test specimen body 4 is subjected to periodic torque loading by adding a torsion disc 6, including: Execute the main loop N times; Each main loop consists of: loading in the first time period; a smaller loop in the second time period; and unloading in the third time period.

[0044] In one embodiment of this application, during the periodic torque loading process, the test piece body 4 is axially reciprocated by the loading cylinder 7, including: During each main cycle, an axial reciprocating sliding displacement of ±S and a sliding frequency of H is applied to the test specimen body 4 through the third loading channel.

[0045] This application can be used for friction and wear tests under different conditions such as different materials, different axial floating amounts, different misalignment amounts, and different lubricating oils. It is a multi-purpose device that greatly reduces testing costs.

[0046] Specifically, the steps include the following: Installation of test specimen body 4: Test specimen body 4 is installed according to... Figure 1 Assemble the components, ensuring the coaxiality of the inner test piece 401 (internal spline) axis and the outer test piece 408 (external spline) axis is within 0.015 mm; apply a thin layer of grease to the inner and outer spline surfaces, fill the lubrication cavity 404 with grease, and then assemble the test piece body 4 according to... Figure 2 Installed inside the test apparatus.

[0047] Testing and commissioning: Determine the torsional load T based on the actual working conditions and requirements of the floating spline. M The axial floating displacement S and the number of main cycles N are calculated. Based on the distance L between the two servo cylinders 19, the applied force F1=F2=T of the torque-applying servo cylinder 19 is calculated. M / L. Connect the calibrated load sensor and displacement sensor to the controller, apply a 40% load to the test piece, eliminate the installation gap, and debug the torque and sliding displacement signals separately. Then, perform a joint test of multiple signals. By adjusting the PID controller parameters, ensure that the multi-channel coordinated loading control channels are normal and that the loading accuracy is guaranteed.

[0048] refer to Figure 4 Torque loading method: Periodic torque loading is applied to the external spline test piece using a torque disk 6. Each loading cycle constitutes one main cycle, which includes three processes: loading, a minor cycle, and unloading. The loading process takes 2 seconds to reach the torque value T. M Then, a small-cycle test was conducted with torque value fluctuation loading, the fluctuation value being ±10%T. M The small-cycle test is performed 500 times; after the small-cycle test is completed, torque unloading is performed for 2 seconds. After one main cycle is completed, the next main cycle loading is started after 1 second, and so on, until the specified number of main cycles N is completed.

[0049] Sliding displacement loading method: During each main cycle of torque loading, axial reciprocating sliding is applied to the external spline test piece through the loading cylinder 7, with a sliding displacement of ±S (the amount of displacement relative to the initial installation position) and a sliding frequency of H.

[0050] The load functions applied in torque loading and sliding displacement loading were designed based on a detailed analysis and calculation of the test loads, resulting in the above three-channel coordinated loading test scheme; F1 and F2 (F1=F2=T M / L) jointly apply the torque load; F3 applies the sliding displacement. Based on the torsional load T M The loading functions for each channel are calculated based on the axial floating displacement S, the sliding frequency H, and the number of main cycles N. F1=0~-F1+0.1×F1sin(180°+ωt)~0(N) F2=0~F1+0.1×F1sin(ωt)~0(N) F3=S×sin (2π×Ht) (mm) Friction and wear analysis of floating splines After the test is completed, a detailed inspection is carried out on the inner test piece 401 and the positioning sections 403 (front positioning section), 406 (rear positioning section), and spline tooth surfaces of the test piece to determine the wear condition of the spline pair 405, including: Dimensions of the front and rear positioning sections and tooth thickness of spline pair 405 are measured. The wear of the spline was measured using a coordinate measuring machine. A 3D topography scanner was used to test the 3D topography and roughness of the internal and external splines.

[0051] Based on the wear amount and wear morphology of spline pair 405, the evaluation results of friction and wear performance under different materials, different heat treatments, different axial floats, different misalignments and different lubricants (greases) are analyzed, and anti-wear schemes for spline pair 405 are proposed.

[0052] This application has used the test method and apparatus to complete the friction and wear test of floating spline pairs with different materials, different surface treatments (carburizing and nitriding, etc.), different surface treatments (DLC coating), and different greases, providing guidance for improving the wear resistance of spline pairs in design.

[0053] In addition, to more significantly reflect the friction and wear condition of the spline pair, the number of main cycles N, the sliding frequency H, and the torque fluctuation can be increased.

[0054] This invention includes test piece design, test apparatus, test method, friction and wear analysis, etc., which can completely simulate the real working conditions of floating splines. It can be used for friction and wear tests of floating spline pairs under different working conditions such as different materials, different heat treatments, different axial floating amounts, different misalignment amounts, and different lubricating oils (greases). The test results are accurate, the test cycle is short, and the test cost is low.

[0055] The test methods and apparatus of this application are simple, accurate, and low in cost, and can meet the requirements for use of aviation floating splines. They are also suitable for comparative tests of friction and wear under different working conditions such as different materials, different heat treatments, different axial floating amounts, different misalignment amounts, and different lubricating oils (greases), to explore the influence mechanism of various factors on the friction and wear of spline pairs.

[0056] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions 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 this application.

Claims

1. A floating spline friction and wear test piece characterized by, It includes an inner test piece (401) and an outer test piece (408); the outer tooth surface of the outer test piece (408) and the inner tooth surface of the inner test piece (401) are fitted together to form a spline pair (405); The end of the spline pair (405) near the inner test piece (401) is a positioning section one (403), and the end of the spline pair (405) near the outer test piece (408) is a positioning section two (406); a lubrication cavity (404) is formed between the positioning section one (403) and the positioning section two (406) of the spline pair (405).

2. A floating spline friction and wear test apparatus characterized by, The test piece includes the test piece body (4), mounting base (2), and support frame (5) as described in claim 1; the inner test piece (401) of the test piece body (4) is mounted on the mounting base (2); the support frame (5) supports the outer test piece (408) of the test piece body (4), and the first end of the support frame (5) is mounted on the mounting base (2); a torsion plate (6) is installed between the second end of the support frame (5) and the outer test piece (408). The torque-adding disc (6) is equipped with a loading cylinder (7) at one end away from the support frame (5); the outer edge of the torque-adding disc (6) is fixedly connected to the outer edge of the loading cylinder (7); the inner edge of the torque-adding disc (6) is fixedly connected to the outer test piece (408); the loading cylinder (7) has an output end of servo cylinder one (12) through a conversion connector; the two ends of the torque-adding disc (6) are respectively connected to the output ends of servo cylinder two (19) through conversion connectors.

3. A floating spline friction and wear test apparatus according to claim 2, wherein The conversion connector includes a lug (8); one end of the lug (8) is mounted on the loading cylinder (7) or the torsion plate (6), and the other end of the lug (8) is connected to the first servo cylinder (12) or the second servo cylinder (19) in sequence through a spherical bearing (10) and a fork-shaped part (11).

4. A floating spline friction and wear test apparatus as set forth in claim 3 wherein, It also includes a base (1), and the mounting base (2) is disposed on the base (1).

5. A floating spline friction and wear test apparatus as set forth in claim 2 wherein, An adjustment pad (3) is provided on the mounting base (2), and the support frame (5) is installed on the adjustment pad (3).

6. A floating spline friction and wear test apparatus as set forth in claim 2, wherein It also includes a bracket (14), which is semi-enclosed and set outside the mounting base (2) and the test piece body (4); the fixed ends of the servo cylinder one (12) and the servo cylinder two (19) are both mounted on the bracket (14).

7. A method of floating spline friction and wear test based on the floating spline friction and wear test device according to any one of claims 2-6, characterized in that, include: The test specimen body (4) is mounted on the test device; According to the working condition of the test piece body (4), the torsional load T M , the axial floating displacement S and the main cycle number N are determined; The applied force of the two servo cylinders (19) is calculated based on the distance L between them. Apply loads to debug the system; The test piece body (4) is subjected to periodic torque loading by adding a torsion disc (6); During the periodic torque loading process, the test piece body (4) is axially reciprocated through the loading cylinder (7); The wear of the test specimen (4) was measured and analyzed to obtain the evaluation results of friction and wear performance.

8. A method of floating spline friction and wear testing according to claim 7 wherein, Applying loads to debug the system includes: First, apply 40% of the target load to the test piece to eliminate the installation gap; Then, the torque loading channel and the displacement loading channel were debugged separately. Finally, multi-channel coordinated loading and joint debugging were performed, and loading accuracy was ensured by adjusting the controller parameters.

9. The floating spline friction and wear test method according to claim 8, characterized in that, The test piece body (4) is subjected to periodic torque loading by adding a torsion disc (6), including: Execute the main loop N times; Each main loop consists of: loading in the first time period; a smaller loop in the second time period; and unloading in the third time period.

10. The floating spline friction and wear test method according to claim 8, characterized in that, During the periodic torque loading process, the test piece body (4) is axially reciprocated through the loading cylinder (7), including: During each main cycle, the test specimen body (4) is subjected to an axial reciprocating sliding displacement of ±S and a sliding frequency of H through the third loading channel.

Images