A large load rolling derivative test device

Abstract

A large-load roll rotation derivative test device belongs to the field of special test technology of aviation aerodynamic wind tunnel. The present invention includes a support sleeve, a drive motor, a first coupling, a motion conversion assembly, a reducer, a second coupling, a vibration shaft, a model support rod and a balance. The model support rod is installed at the end of the support sleeve, and the drive motor is fixedly installed in the support sleeve. The drive motor is connected to the motion conversion assembly through the first coupling, and the motion conversion assembly is connected to the input end of the reducer. The output end of the reducer is connected to one end of the vibration shaft through the second coupling, and the other end of the vibration shaft passes through the model support rod and is connected to the balance. The research and development purpose of the present invention is to solve the problem of non-standard sinusoidal motion caused by insufficient overall stiffness of the mechanism, thereby improving the test accuracy of the roll rotation derivative, changing the direct drive of the eccentric cam to indirect drive, reducing the force and loss of the cam, and improving the service life of the mechanism.

Description

Technical Field

[0001] The invention relates to a large-load rolling derivative test device, belonging to the technical field of special tests of aviation aerodynamic wind tunnels. Background Art

[0002] The high-speed dynamic derivative test is a special wind tunnel test to obtain the dynamic derivative coefficients of the aircraft in the pitch, yaw and roll directions. The current mainstream test process is to force the aircraft to perform sinusoidal motion in the pitch, yaw and roll directions to obtain the dynamic derivatives in the three directions. The pitch and yaw motion directions are similar and can share a set of test mechanisms, but the sinusoidal motion in the roll direction requires rolling motion around the center line of the model, and the corresponding mechanism needs to be designed separately.

[0003] As a mature test technology, the high-speed wind tunnel roll derivative test has a basic structural form of a conventional roll test device: a motor, a reducer, a coupling, a combination of motion conversion components, a main vibration axis, a test balance, and a test model. In order to achieve a certain amplitude of the model's rolling sinusoidal motion, the motion conversion component is usually mainly composed of an eccentric pulley and a transmission structure. The eccentric pulley rotates through the motor and the reducer, and drives the main vibration axis to swing left and right through the transmission structure, thereby achieving the sinusoidal motion of the aircraft. The ratio between the distance between the motor axis and the main vibration axis and the eccentricity of the eccentric pulley determines the angular amplitude of the roll vibration.

[0004] Due to the limitation of the structural size in the roll wind tunnel test, the distance between the motor axis and the main vibration axis will not be too large. For the existing main temporary impulse wind tunnel with a diameter of 1.2 meters, in order to eliminate the influence of the branches of the tail support and meet the wind tunnel blockage and other issues, the specific distance is usually within 50 mm. For the high-speed roll derivative test, the roll vibration amplitude is about 1.5°. In order to meet the amplitude requirements, the eccentricity of the eccentric pulley is determined to be very small, usually less than 1.4 mm. Due to the small eccentricity, there are two obvious defects: the motion conversion component is small in size and weak in rigidity. Under large load conditions, the vibration distortion of the model is large and there is a problem of damage to the eccentric pulley after several wind blowing tests; and due to the small size, the processing requirements are high. If there is an assembly gap in the entire mechanism, the gap will have a large impact during the movement. Typically, under large loads, the vibration amplitude of the model is significantly reduced, and during the motion transmission process, a part of the motion amplitude is worn away, which seriously affects the test quality.

[0005] Therefore, it is urgent to propose a large-load rolling derivative test device to solve the above technical problems. Summary of the invention

[0006] The purpose of the present invention is to solve the problem of non-standard sinusoidal motion caused by insufficient overall stiffness of the mechanism, thereby improving the test accuracy of the rolling derivative. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to determine the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0007] The technical solution of the present invention:

[0008] A large-load rolling derivative test device comprises a support sleeve, a driving motor, a first coupling, a motion conversion assembly, a reducer, a second coupling, a vibration shaft, a model support rod and a balance. The model support rod is installed at the end of the support sleeve, and the driving motor is fixedly installed in the support sleeve. The driving motor is connected to the motion conversion assembly through the first coupling, the motion conversion assembly is connected to the input end of the reducer, and the output end of the reducer is connected to one end of the vibration shaft through the second coupling. The other end of the vibration shaft passes through the model support rod and is connected to the balance.

[0009] Preferably: the motion conversion assembly includes an eccentric cam, a conversion block and a support bearing, one end of the eccentric cam is fixedly connected to the output end of the driving motor through a first coupling, the other end of the eccentric cam is provided with an eccentric sliding shaft, the support bearing is fixedly installed in the support sleeve, the conversion block is rotatably installed on the support bearing, one end of the conversion block is provided with a slide groove, the eccentric sliding shaft is slidably arranged in the slide groove, and the other end of the conversion block is connected to the input end of the reducer.

[0010] Preferably, the driving motor is fixedly connected to the first coupling via a driving reducer.

[0011] Preferably: the driving reducer drives the rotational angular velocity of the motor The speed reduction is the angular velocity required by the test The test required angular velocity is Transfer to the motion conversion component;

[0012] For the motion conversion assembly, the eccentric cam is driven by the circular motion of the reducer, which drives the conversion block to swing left and right in a sinusoidal motion;

[0013] The sinusoidal motion of the conversion block swinging left and right passes through the reducer, reducing the amplitude of the sinusoidal motion to the rotation angle required for the test, thereby driving the vibration axis to perform rolling sinusoidal motion, and then driving the model to move, completing the test process.

[0014] Preferably: the angular velocity ratio of the output end to the input end of the reducer is the reduction ratio n of the reducer;

[0015] Then the angular velocity of the reducer input is:

[0016] ;

[0017] The angular velocity at the output of the reducer is:

[0018] ;

[0019] Among them = , , to ensure the test angular velocity constant.

[0020] The present invention has the following beneficial effects:

[0021] 1. The present invention significantly improves the load capacity of the rolling motion mechanism without increasing the size of the mechanism, thereby improving the overall stiffness of the rolling rotation derivative mechanism, reducing the sensitivity of the mechanism to the gap, increasing the natural frequency of the mechanism in the rolling direction, and improving the vibration stability, thereby improving the measurement accuracy of the test and meeting the requirements of the large-load rolling rotation derivative test;

[0022] 2. The eccentric distance of the eccentric cam of the present invention is increased, which can reduce the sensitivity of the mechanism to the assembly gap. Under the condition of the same machining level, the sinusoidality of the mechanism vibration can be greatly improved, thereby improving the test accuracy;

[0023] 3. The structural design of the present invention is simple. Under the limited wind tunnel size, the size of the mechanism is not increased, the wind tunnel blockage requirement is met, the direct drive of the eccentric cam is changed to indirect drive, the cam force and loss are reduced, and the service life of the mechanism is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a large load rolling derivative test device;

[0025] Figure 2 is a schematic structural diagram of a motion conversion assembly of the present invention;

[0026] Figure 3 It is a stereogram of a large load rolling derivative test device;

[0027] Figure 4 is an exploded view of the motion conversion assembly of the present invention;

[0028] Figure 5 It is a stereoscopic view of the motion conversion assembly of the present invention.

[0029] In the figure: 1-support sleeve, 2-drive motor, 3-first coupling, 4-motion conversion assembly, 5-reducer, 6-second coupling, 7-vibration shaft, 8-model support rod, 9-balance, 21-drive reducer, 41-eccentric cam, 42-conversion block, 43-support bearing, 44-eccentric sliding shaft, 45-slide groove. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0031] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but not limited to conventional detachable methods such as threaded connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can always be found in the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs. For example: a fixed connection is selected as a welding connection, and a detachable connection is selected as a hinge connection.

[0032] Specific implementation method 1: Combination Figure 1-Figure 5 The present embodiment is described. A large-load rolling derivative test device of the present embodiment includes a support sleeve 1, a drive motor 2, a first coupling 3, a motion conversion assembly 4, a reducer 5, a second coupling 6, a vibration shaft 7, a model support rod 8 and a balance 9. The model support rod 8 is installed at the end of the support sleeve 1, and the drive motor 2 is fixedly installed in the support sleeve 1. The drive motor 2 is connected to the motion conversion assembly 4 through the first coupling 3, the motion conversion assembly 4 is connected to the input end of the reducer 5, and the output end of the reducer 5 is connected to one end of the vibration shaft 7 through the second coupling 6. The other end of the vibration shaft 7 passes through the model support rod 8 and is connected to the balance 9.

[0033] The motion conversion assembly 4 includes an eccentric cam 41, a conversion block 42 and a support bearing 43. One end of the eccentric cam 41 is fixedly connected to the output end of the driving motor 2 via a first coupling 3. An eccentric sliding shaft 44 is provided at the other end of the eccentric cam 41. The support bearing 43 is fixedly installed in the support sleeve 1. The conversion block 42 is rotatably installed on the support bearing 43. A slide groove 45 is provided at one end of the conversion block 42. The eccentric sliding shaft 44 is slidably arranged in the slide groove 45. The other end of the conversion block 42 is connected to the input end of the reducer 5.

[0034] The eccentric cam 41 increases the eccentric distance, which can reduce the sensitivity of the mechanism to the assembly clearance. Under the same machining level, it can greatly improve the sinusoidal nature of the mechanism vibration and improve the test accuracy. This solves the problems of the rolling derivative test device being too small in the existing wind tunnel test technology, the mechanism assembly clearance having a great influence on the test results, and the technical difficulties that the vibration stiffness of the mechanism cannot be improved.

[0035] The driving motor 2 is fixedly connected to the first coupling 3 via a driving reducer 21 .

[0036] The driving reducer 21 drives the rotational angular velocity of the motor 2 The speed reduction is the angular velocity required by the test , and the test required angular velocity is transferred to Transfer to the motion conversion component 4;

[0037] For the motion conversion assembly 4, the eccentric cam 41 is driven by the circular motion brought by the reducer 21, driving the conversion block 42 to swing left and right in a sinusoidal motion;

[0038] The sinusoidal motion of the conversion block 42 swinging left and right passes through the reducer 5, and the amplitude of the sinusoidal motion is reduced to the rotation angle required for the test, thereby driving the vibration shaft 7 to perform rolling sinusoidal motion, and then driving the model to move, completing the test process.

[0039] The angular velocity ratio of the rotation angle between the output end and the input end of the reducer 5 is the reduction ratio n of the reducer 5; the reducer 5 reduces the frequency rather than the rotation speed.

[0040] Then the angular velocity of the input end of the reducer 5 is:

[0041] ;

[0042] The angular velocity of the output end of reducer 5 is:

[0043] ;

[0044] Among them = , , to ensure the test angular velocity constant.

[0045] The difference between the input and output of the reducer 5 is not the vibration frequency, but the vibration amplitude. The input and output vibration frequencies of the reducer 5 are the same, and the amplitude ratio is equal to the reduction ratio of the reducer. In this way, a large amplitude vibration is achieved before the reducer 5, and a small amplitude vibration is achieved for the vibration shaft 7. Since the rotation amplitude of the motion conversion mechanism 4 is increased, the eccentricity of the eccentric cam 41 is increased, and then the overall stiffness of the eccentric cam 41 can be improved, thereby ensuring the stiffness of the entire test mechanism and improving the test accuracy.

[0046] The working principle of this implementation is as follows:

[0047] When the driving motor 2 is powered on, it performs continuous rotational motion, and reaches the frequency required for the test through the driving reducer 21. The rotational motion is transmitted to the eccentric cam 41 through the first coupling 3. When the eccentric cam 41 rotates, it moves up and down in the slide slot 45 of the conversion block 42, and drives the conversion block 42 to swing left and right. Because the lower part of the conversion block 42 is constrained by the bottom support bearing 43, the eccentric cam 41 drives the conversion block 42 to swing left and right around the support bearing 43. In this way, under the combined action of the constraint and the eccentric pulley drive, the conversion block 42 performs a sinusoidal swing around the axis of the support bearing 43. At the same time, the right end of the conversion block 42 is designed to be cylindrical, and the cylinder coincides with the axis of the support bearing 43. The left and right swing of the conversion block 42 drives the cylinder to perform a sinusoidal rotation around its own axis. The cylinder is connected to the input end of the reducer 5. When the cylinder performs left and right sinusoidal motion, the reducer 5 receives a sinusoidal input. For the gear reducer, the large-amplitude sinusoidal motion can be converted into a small-amplitude sinusoidal motion. The reduction ratio of the reducer 5 is adjusted to a specified value so that the amplitude of the output end of the reducer 5 is the test set value. The reducer 5 is connected to the vibration shaft 7 through the coupling 26, and the vibration shaft 7 is connected to the balance 9. At this time, the vibration shaft 7 can perform the set sinusoidal motion. In addition, the test model can be installed on the balance. Through a series of rotations, the sinusoidal motion of the model is realized, thereby completing the rolling derivative test.

[0048] The test range that can be achieved in this embodiment is a vibration frequency of 4-15 Hz, an amplitude of 8 degrees at the driving end, and an amplitude of 1.8 degrees for the model vibration.

[0049] A large load rolling derivative test device of this embodiment, based on the test method adopted by the device is as follows:

[0050] Step 1, installing the large-load rolling derivative test device on a wind tunnel scimitar and supporting it in a wind tunnel test section through the scimitar;

[0051] Step 2, installing the test model on the large-load rolling rotation derivative test device and closely matching it, so that the model can be forced to perform a forced rolling motion through the large-load rolling rotation derivative test device;

[0052] Step 3, connect the power line and the control line to the external control computer, and connect the data acquisition line to the acquisition device;

[0053] Step 4: Conduct non-winding debugging to verify the stability of the mechanism and collect data of the model without wind load;

[0054] Step 5, after completing steps 1 to 4, close the wind tunnel and conduct a wind test;

[0055] Step 6: After the flow field is stabilized, the control mechanism performs rolling simple harmonic motion, sets the angle of attack sequence, drives the model and the mechanism to move to the corresponding angle of attack through the scimitar, and collects the corresponding data;

[0056] Step 7: After all angles of attack are collected, close the wind tunnel and the test is completed.

[0057] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A large load rolling derivative test device, characterized in that: The invention comprises a support sleeve (1), a driving motor (2), a first coupling (3), a motion conversion assembly (4), a reducer (5), a second coupling (6), a vibration shaft (7), a model support rod (8) and a balance (9); the model support rod (8) is installed at the end of the support sleeve (1); the driving motor (2) is fixedly installed in the support sleeve (1); the driving motor (2) is connected to the motion conversion assembly (4) through the first coupling (3); the motion conversion assembly (4) is connected to the input end of the reducer (5); the output end of the reducer (5) is connected to one end of the vibration shaft (7) through the second coupling (6); the other end of the vibration shaft (7) passes through the model support rod (8) ) and a balance (9); the motion conversion assembly (4) comprises an eccentric cam (41), a conversion block (42) and a support bearing (43); one end of the eccentric cam (41) is fixedly connected to the output end of the drive motor (2) via a first coupling (3); the other end of the eccentric cam (41) is provided with an eccentric sliding shaft (44); the support bearing (43) is fixedly installed in the support sleeve (1); the conversion block (42) is rotatably installed on the support bearing (43); one end of the conversion block (42) is provided with a sliding groove (45); the eccentric sliding shaft (44) is slidably installed in the sliding groove (45); the other end of the conversion block (42) is connected to the input end of the reducer (5); The driving motor (2) is fixedly connected to the first coupling (3) via a driving reducer (21); The driving reducer (21) drives the motor (2) to rotate at an angular velocity ω n The speed reduction is the angular velocity ω required by the test i , and the test required angular velocity ω is transmitted through the first coupling (3) i Transfer to the motion conversion component (4); For the motion conversion component (4), the eccentric cam (41) is driven by the circular motion of the reducer (21), driving the conversion block (42) to swing left and right in a sinusoidal motion; The sinusoidal motion of the conversion block (42) swinging left and right passes through the reducer (5), and the amplitude of the sinusoidal motion is reduced to the rotation angle required for the test, thereby driving the vibration shaft (7) to perform rolling sinusoidal motion, and then driving the model to move, completing the test process.

2. A large load rolling derivative test device according to claim 1, characterized in that: The ratio of the rotational angular velocity between the output end and the input end of the reducer (5) is the reduction ratio n of the reducer (5); Then the angular velocity of the input end of the reducer (5) is: i i =θ i sin(ω i t) The angular velocity at the output end of the reducer (5) is: i o =θ o sin(ω o t) Among them, ω i =ω o , Ensure the test angular velocity ω i constant.

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