Helicopter rotor blade root section fatigue test device and method

Abstract

The invention provides a helicopter rotor blade root section fatigue test device and method, and the device comprises a fixed joint which is connected with a test bench; the cover plate is connected with the fixed joint; the thrust ball bearing fake piece is arranged in the mounting hole of the cover plate, and the thrust ball bearing fake piece is located on one side of the shaft shoulder of the test piece; the deep groove ball bearing fake part is located on the other side of the shaft shoulder; the adapter plate is connected with the end face of the test piece; the loading fork lug is connected with the test piece; the adapter fork lug is connected with the loading fork lug, and two connecting plates are arranged on the outer side of the adapter fork lug; the steel wire rope assembly is connected to the center positions of the two connecting plates; the centrifugal loading servo mechanism is connected with the steel wire rope assembly; the waving loading fork lug is connected to the middle of the switching fork lug; the connecting rod is connected with the waving loading fork lug; the bending moment loading servo mechanism is connected with the connecting rod; according to the invention, the problem of the fatigue test technology of the rotor blade root section of a new-configuration electric-driven vertical take-off and landing helicopter is solved.

Description

Technical Field

[0001] This application belongs to the technical field of fatigue testing, and particularly relates to a fatigue test device and method for the root section of a helicopter rotor blade. Background Art

[0002] The main loads borne by the rotor of a new configuration electric vertical takeoff and landing helicopter are the flapping, lead-lag, and centrifugal force loads during the flight of the blade. In order to explore the fatigue performance and weak parts of the root section of the rotor blade of the new configuration electric vertical takeoff and landing helicopter, a fatigue test of the root section of the helicopter rotor blade needs to be carried out. Summary of the Invention

[0003] Objective of the Invention: To provide a fatigue test device and method for the root section of a helicopter rotor blade, so as to achieve the purpose of solving the fatigue device test technology for the root section of a helicopter rotor blade and exploring the fatigue performance of the root section of a helicopter rotor blade.

[0004] In a first aspect, this application provides a fatigue test device for the root section of a helicopter rotor blade, including a fixing component and a loading component;

[0005] The fixing component includes:

[0006] A test bench;

[0007] A fixing joint, one end of which is connected to the test bench;

[0008] A cover plate, connected to the other end of the fixing joint; one end of the root section of the helicopter rotor blade is connected to the cover plate; an installation hole is provided on one side of the cover plate; one end of the root section of the helicopter rotor blade has a shoulder;

[0009] A thrust ball bearing dummy, arranged in the installation hole, and the thrust ball bearing dummy is located on one side of the shoulder;

[0010] A deep groove ball bearing dummy, located on the other side of the shoulder;

[0011] An adapter plate, connected to the end face of the root section of the helicopter rotor blade, and the deep groove ball bearing dummy is connected to the adapter plate; wherein, the thrust ball bearing dummy, the deep groove ball bearing dummy, and the adapter plate are all located between the cover plate and the other end of the fixing joint;

[0012] The loading component includes:

[0013] A loading fork ear, one end of which is connected to the other end of the root section of the helicopter rotor blade;

[0014] The adapter fork ear, one end of the adapter fork ear is connected to the other end of the loading fork ear, and two connecting plates are provided at the other end of the adapter fork ear;

[0015] The wire rope assembly, one end of the wire rope assembly is connected to the central position of the two connecting plates;

[0016] The centrifugal loading servo mechanism is connected to the other end of the wire rope assembly;

[0017] The flapping loading fork ear, one end of the flapping loading fork ear is connected to the middle of the adapter fork ear;

[0018] The connecting rod, one end of the connecting rod is connected to the other end of the flapping loading fork ear;

[0019] The bending moment loading servo mechanism is connected to the other end of the connecting rod.

[0020] Preferably, the fixing component can fix the root section of the helicopter rotor blade at a target angle.

[0021] Preferably, the centrifugal loading servo mechanism can make the root section of the helicopter rotor blade reach the target displacement, simulating the loading form of the centrifugal force received by the helicopter during flight;

[0022] The bending moment loading servo mechanism is used to apply flapping and pitching loads to the root section of the helicopter rotor blade, simulating the loading forms of flapping and pitching received by the helicopter during flight.

[0023] Preferably, the loading component further includes:

[0024] The sliding plate is connected to the outside of the connecting plate; an oil groove is provided on the sliding plate, and a lubricating grease is applied to the end face of the sliding plate, and the lubricating grease can flow along the oil groove.

[0025] Preferably, a gap is reserved between the thrust ball bearing dummy and the circular surface of the root section of the helicopter rotor blade.

[0026] Preferably, a gap is reserved between the deep groove ball bearing dummy and the end face of the mounting hole.

[0027] In a second aspect, the present application also provides a fatigue test method for the root section of a helicopter rotor blade. The method is applied to the fatigue test device for the root section of a helicopter rotor blade as described above. The fatigue test method for the root section of a helicopter rotor blade includes:

[0028] Step 101, rotate the root section of the helicopter rotor blade by a certain angle, the rotated angle can ensure that the test load meets the phase requirements of the test loads in the flapping and pitching directions during the test. After pressing the cover plate with bolts, control the centrifugal loading servo mechanism to apply centrifugal force;

[0029] Step 201: Tighten the tightening nut on the loading fork ear, then control the moment loading servo mechanism to load by controlling the displacement, collect test data for analysis to obtain the moment loads of flapping and pitching. If the moment loads of the test flapping and pitching just meet the test requirements, conduct the fatigue test; if not, loosen the bolts on the cover plate and also loosen the tightening nut on the loading fork ear, rotate the installation angle of the root section of the helicopter rotor blade, repeat the above loading steps, and continuously adjust the installation angle of the root section of the helicopter rotor blade and the moment loading servo mechanism to load by controlling the displacement until the moment loads of the test flapping and pitching meet the test requirements.

[0030] Preferably, before step 101, it further includes:

[0031] Install the deep groove ball bearing dummy and the adapter plate on one end of the root section of the helicopter rotor blade with bolts to form an integral body for subsequent installation; install the thrust ball bearing dummy in the installation hole of the cover plate;

[0032] Fix the fixed joint on the test bench with bolts, install the root section of the helicopter rotor blade installed in the above steps on the fixed joint, and the cover plate can press the deep groove ball bearing dummy and the adapter plate through bolts;

[0033] Connect the threaded end of the loading fork ear to the tightening nut and the adapter fork ear, connect the adapter fork ear to the flapping loading fork ear in the middle, connect the flapping loading fork ear to the connecting rod, connect the connecting rod to the moment loading servo mechanism, connect the two connecting plates to the outside of the adapter fork ear and then connect the sliding plate, connect the wire rope assembly at the center position of the two connecting plates, connect the wire rope assembly to the centrifugal loading servo mechanism. After the above installation is completed, connect the loading fork ear to the other end of the root section of the helicopter rotor blade with bolts.

[0034] The present application has the following technical effects:

[0035] A fatigue test device and method for the root section of a helicopter rotor blade provided by the present application are simple and practical, with relatively low processing and maintenance costs, solve the problem of the fatigue test technology for the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter, and achieve the purpose of evaluating the fatigue characteristics of the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter. Description of the Drawings

[0036] Figure 1 is the overall structural schematic diagram of a fatigue test device for the root section of a helicopter rotor blade provided by an embodiment of the present application;

[0037] Figure 2 is the partial structural schematic diagram of a fatigue test device for the root section of a helicopter rotor blade provided by an embodiment of the present application;

[0038] Figure 3 It is a schematic structural diagram of a fixed joint provided by an embodiment of the present application;

[0039] Figure 4 It is a schematic structural diagram of a cover plate provided by an embodiment of the present application. Detailed implementation manners

[0040] A fatigue test device and method for the root section of a helicopter rotor blade provided by the present application support the research on the fatigue test technology of the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter. This device simulates the loading forms of flapping, lead-lag loads and centrifugal force loads during the flight of the helicopter, and has a simple structure and is convenient to install.

[0041] Using this device can fully evaluate the fatigue performance and weak parts of the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter, and provide data support for the design of the rotor blade of a new configuration electric vertical takeoff and landing helicopter.

[0042] Please refer to Figures 1 to 4 for a further detailed description of the present application.

[0043] As Figure 1 and Figure 2 shown, the present application provides a fatigue test device for the root section of a helicopter rotor blade, including: a fixed joint 1, a cover plate 2, a thrust ball bearing dummy 3, a deep groove ball bearing dummy 4, a transfer plate 5, a test piece 6, a loading fork ear 7, a tightening nut 8, a transfer fork ear 9, a sliding plate 10, a connecting plate 11, a wire rope assembly 12, a flapping loading fork ear 13, and a connecting rod 14.

[0044] Among them, as Figure 3 and Figure 4 shown, the designed outer shape of the fixed joint 1 is an I-shaped structure. One end of the fixed joint 1 is fixedly connected to the test bench, and the other end is bolted to the cover plate 2.

[0045] Furthermore, the test bench includes a base and a mounting joint provided on the base, and this mounting joint is used to mount the fixed joint.

[0046] It should be noted that the test bench in the embodiment of the present application mainly plays a fixing role. That is to say, any test bench that can play a fixing role can be used.

[0047] Among them, one side of the cover plate 2 is machined with a mounting hole, and this mounting hole is a stepped groove hole. A thrust ball bearing dummy 3, a test piece 6 (the root section of the helicopter rotor blade), a deep groove ball bearing dummy 4, and a transfer plate 5 are connected between the cover plate and the fixed joint.

[0048] In the embodiment of the present application, the connection method is to place a thrust ball bearing dummy 3 in the inner mounting hole of the cover plate 2. One side of the thrust ball bearing dummy 3 is connected to the shoulder of the root section of the helicopter rotor blade, and the other side of the shoulder is connected to a deep groove ball bearing dummy 4. The deep groove ball bearing dummy 4 is connected to the adapter plate 5 through a bolt hole, and the adapter plate 5 is connected to the end face of the test piece 6 through bolts.

[0049] Among them, the loading end of the test piece 6 is connected to the loading fork ear 7 through bolts. The end connection of the loading fork ear 7 is machined with threads and is connected to the inside of the transfer fork ear 9 through the threads. It is tightened by tightening the nut 8. The transfer fork ear 9 is connected to a sliding plate 10 on each side through an intermediate connecting rod on the left and right.

[0050] In the embodiment of the present application, a flapping loading fork ear 13 is connected in the middle of the transfer fork ear 9. The flapping loading fork ear 13 is connected to the connecting rod 14, and the other end of the connecting rod 14 is connected to the bending moment loading servo mechanism. The outside of the transfer fork ear 9 is connected to the connecting plate 11, and the connecting plate is then connected to the sliding plate 10. The center positions of the two connecting plates 11 are connected to the wire rope assembly 12, and the other end of the wire rope assembly 12 is connected to the centrifugal loading servo mechanism.

[0051] Among them, it is designed that the thrust ball bearing dummy 3 does not contact the root circular surface of the test piece 6 to ensure that only the centrifugal force acts on the shoulder part of the test piece 6 during the test and no bending moment acts. When designing the deep groove ball bearing dummy 4, it only contacts the back of the shoulder of the root section of the test piece 6 and does not contact the end face of the stepped groove hole of the cover plate 2 to ensure that the root section part of the test piece 6 bears the bending moment and does not bear the centrifugal force during the test.

[0052] Among them, the sliding plate 10 is machined with an oil groove, and grease is applied to its end face before the test to reduce the friction during the bending moment loading and prevent the test bench from heating during the fatigue test.

[0053] In other embodiments of the present application, a fatigue test device for the root section of a helicopter rotor blade can achieve coordinated loading in three directions: flapping, pitching, and centrifugal force of the root section of the blade.

[0054] Among them, the flapping and pitching of the root section of the blade are achieved by rotating the angle of a bending moment loading servo mechanism. By loosening the fixing bolts of the cover plate 2 and the tightening nut 8 on the loading fork ear 7 at both ends of the test piece 6, the angle can be freely rotated. When the fixing bolts of the cover plate 2 and the tightening nut 8 are tightened, it will no longer rotate. When the test enters the debugging stage, the bending moment loading servo mechanism applies a load and then rotates the angle in the above manner to adjust the flapping and pitching loads to meet the test requirements.

[0055] A fatigue test device for the root section of a helicopter rotor blade provided by the present application is simple and practical, with relatively low processing and maintenance costs, solves the problem of the fatigue test technology for the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter, and achieves the purpose of evaluating the fatigue characteristics of the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter.

[0056] In other embodiments of the present application, a fatigue test method for the root section of a helicopter rotor blade is also provided. The method includes the following steps:

[0057] Step 1: Before installing the test piece, first install the deep groove ball bearing dummy 4 and the adapter plate 5 on the root fixed end of the test piece with bolts to form an integral body for subsequent installation; install the thrust ball bearing dummy in the mounting hole of the cover plate.

[0058] Step 2: After Step 1 is completed, install the test piece. Fix the fixed joint 1 on the test bench with bolts, install the test piece installed in Step 1 on the fixed joint 1, and press the cover plate 2 against the deep groove ball bearing dummy 4 and the adapter plate 5 with bolts to complete the installation of the fixed end structure of the test piece.

[0059] Step 3: After completing Step 2, install the loading end of the test piece. First, connect the loading fork ear 7, thread the end to tighten the nut 8 and the adapter fork ear 9. The adapter fork ear 9 is connected to a sliding plate 10 on each side through an intermediate connecting rod on the left and right. The adapter fork ear 9 is connected to the flap loading fork ear 13 in the middle. The flap loading fork ear 13 is then connected to the connecting rod 14. The other end of the connecting rod 14 is connected to the moment loading servo mechanism. The outside of the adapter fork ear 9 is connected to the connecting plate 11 and then to the sliding plate 10. The center positions of the two connecting plates 11 are connected to the wire rope assembly 12. The other end of the wire rope assembly 12 is connected to the centrifugal loading servo mechanism. After the above installation is completed, connect the loading fork ear 7 to the loading end of the test piece with bolts.

[0060] Step 4. After completing Step 3, the test piece is installed, and the test debugging is entered. First, rotate the test piece by a certain angle, and the rotation angle can ensure that the test load meets the phase requirements of the test loads in the flapping and lag directions during the test. After pressing the cover plate 2 at the fixed end of the test piece with bolts, control the centrifugal loading servo mechanism to apply centrifugal force. Then, tighten the locking nut 8 on the loading fork ear 7 connected to the loading end of the test piece. Next, control the moment loading servo mechanism to apply load by controlling the displacement, and collect test data for analysis to obtain the flapping and lag moment loads. If the flapping and lag moment loads of the test just meet the test requirements, conduct the fatigue test. When the test load does not meet the load requirements, loosen the bolts on the cover plate 2 and also loosen the locking nut 8 on the loading fork ear 7, rotate the installation angle of the test piece, and repeat the above loading steps. By continuously adjusting the installation angle of the test piece and controlling the moment loading servo mechanism to apply load by controlling the displacement, until the flapping and lag moment loads of the test meet the test requirements; among them, in the above debugging process, the adjustment of the installation angle mainly changes the proportion of the test piece load in the flapping and lag directions, and the control of the displacement mainly changes the magnitude change of the test piece load in the flapping and lag directions.

[0061] Step 5. After continuous debugging through Step 4 to obtain the test load that meets the test requirements, record the target angle and target displacement that are satisfied after the debugging, and apply load according to this angle and displacement to enter the fatigue test. During the test, the installation angle and the controlled displacement remain unchanged. Design protection limits and test errors in the control system, observe the load and test conditions on the test piece according to the inspection requirements of the test requirements, and terminate the test with reference to the test termination conditions.

[0062] A fatigue test method for the root section of a helicopter rotor blade provided by the present application is simple and practical, with relatively low processing and maintenance costs, solves the problem of the fatigue test technology for the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter, and achieves the purpose of evaluating the fatigue characteristics of the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter.

[0063] In other embodiments of the present application, a fatigue test device for the root section of a helicopter rotor blade is further provided, including: a fixed joint connected to a test bench; a cover plate connected to the fixed joint; a thrust ball bearing dummy arranged in the mounting hole of the cover plate, with the thrust ball bearing dummy located on one side of the shoulder of the test piece; a deep groove ball bearing dummy located on the other side of the shoulder; an adapter plate connected to the end face of the test piece; a loading fork ear connected to the test piece; a transfer fork ear connected to the loading fork ear, with two connecting plates arranged on the outside of the transfer fork ear; a wire rope assembly connected to the central positions of the two connecting plates; a centrifugal loading servo mechanism connected to the wire rope assembly; a flapping loading fork ear connected to the middle of the transfer fork ear; a connecting rod connected to the flapping loading fork ear; a bending moment loading servo mechanism connected to the connecting rod; The present application solves the problem of the fatigue test technology for the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter.

[0064] A fatigue test device and method for the root section of a helicopter rotor blade provided by the present application are simple and practical, with relatively low processing and maintenance costs. It solves the problem of the fatigue test technology for the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter, and achieves the purpose of evaluating the fatigue characteristics of the root section of the rotor blade of a new configuration electric vertical takeoff and landing helicopter.

Claims

1. A fatigue test device for the root section of a helicopter rotor blade, characterized in that It includes a fixed component and a loading component; The fixed component includes: A test bench; A fixed joint, one end of which is connected to the test bench; A cover plate, connected to the other end of the fixed joint; one end of the root section of the helicopter rotor blade is connected to the cover plate; there is a mounting hole on one side of the cover plate; one end of the root section of the helicopter rotor blade has a shoulder; A thrust ball bearing dummy, arranged in the mounting hole, and the thrust ball bearing dummy is located on one side of the shoulder; A deep groove ball bearing dummy, located on the other side of the shoulder; An adapter plate, connected to the end face of the root section of the helicopter rotor blade, and the deep groove ball bearing dummy is connected to the adapter plate; wherein, the thrust ball bearing dummy, the deep groove ball bearing dummy and the adapter plate are all located between the cover plate and the other end of the fixed joint; The loading component includes: A loading fork ear, one end of which is connected to the other end of the root section of the helicopter rotor blade; An adapter fork ear, one end of which is connected to the other end of the loading fork ear, and there are two connecting plates arranged at the other end of the adapter fork ear; A wire rope assembly, one end of which is connected to the central position of the two connecting plates; A centrifugal loading servo mechanism, connected to the other end of the wire rope assembly; A flapping loading fork ear, one end of which is connected to the middle of the adapter fork ear; A connecting rod, one end of which is connected to the other end of the flapping loading fork ear; A moment loading servo mechanism, connected to the other end of the connecting rod.

2. The fatigue test device for the root section of a helicopter rotor blade according to claim 1, characterized in that, The fixed component can fix the root section of the helicopter rotor blade at a target angle.

3. The fatigue test device for the root section of a helicopter rotor blade according to claim 1, characterized in that, The centrifugal loading servo mechanism can make the root section of the helicopter rotor blade reach a target displacement, simulating the loading form of the centrifugal force received by the helicopter during flight; The moment loading servo mechanism is used to apply flapping and pitching loads to the root section of the helicopter rotor blade, simulating the loading forms of flapping and pitching received by the helicopter during flight.

4. The fatigue test device for the root section of a helicopter rotor blade according to claim 1, wherein, The loading component further includes: A sliding plate, connected to the outer side of the connecting plate; there is an oil groove on the sliding plate, and lubricating grease is smeared on the end face of the sliding plate, and the lubricating grease can flow along the oil groove.

5. The fatigue test device for the root section of a helicopter rotor blade according to claim 1, characterized in that, A gap is reserved between the thrust ball bearing dummy and the circular surface of the root section of the helicopter rotor blade.

6. The fatigue test device for the root section of a helicopter rotor blade according to claim 1, characterized in that, A gap is reserved between the deep groove ball bearing dummy and the end face of the mounting hole.

7. A fatigue test method for the root section of a helicopter rotor blade, characterized in that, The method is applied to the fatigue test device for the root section of the helicopter rotor blade as described in any one of claims 1-6, and the fatigue test method for the root section of the helicopter rotor blade includes: Step 101: Rotate the root section of the helicopter rotor blade by a certain angle, and the rotated angle can ensure that the test load meets the phase requirements of the test loads in the flapping and pitching directions during the test. After pressing the cover plate with bolts, control the centrifugal loading servo mechanism to apply centrifugal force; Step 201: Tighten the tightening nut on the loading fork ear, and then control the moment loading servo mechanism to perform loading by controlling the displacement. Collect test data for analysis to obtain the moment loads of flapping and lead-lag. If the moment loads of flapping and lead-lag in the test just meet the test requirements, conduct the fatigue test; if they do not meet the test requirements, loosen the bolts on the cover plate and also loosen the tightening nut on the loading fork ear, rotate the installation angle of the root section of the helicopter rotor blade, repeat the above loading steps, and continuously adjust the installation angle of the root section of the helicopter rotor blade and the moment loading servo mechanism to perform loading by controlling the displacement until the moment loads of flapping and lead-lag in the test meet the test requirements.

8. The fatigue test method for the root section of a helicopter rotor blade according to claim 7, characterized in that, Before the said step 101, it further includes: Install the deep groove ball bearing dummy and the adapter plate at one end of the root section of the helicopter rotor blade with bolts to form an integral unit for subsequent installation; install the thrust ball bearing dummy in the mounting hole of the cover plate; Fix the fixed joint to the test bench with bolts, install the root section of the helicopter rotor blade installed in the above steps on the fixed joint, and the cover plate can press the deep groove ball bearing dummy and the adapter plate through bolts; Connect the threaded end of the loading fork ear to the tightening nut and the adapter fork ear, connect the adapter fork ear to the flapping loading fork ear in the middle, connect the flapping loading fork ear to the connecting rod, connect the connecting rod to the moment loading servo mechanism, connect two connecting plates to the outside of the adapter fork ear and then connect the sliding plate, connect the wire rope assembly to the center position of the two connecting plates, connect the wire rope assembly to the centrifugal loading servo mechanism. After the above installation is completed, connect the loading fork ear to the other end of the root section of the helicopter rotor blade with bolts.

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