Double-rotating-shaft mechanism for wind tunnel test

Abstract

The invention belongs to the technical field of wind tunnel tests, and discloses a double-rotating-shaft mechanism for a wind tunnel test. A Z-shaped connecting support plate is mounted above the middle section of a front shaft of the double-rotating-shaft mechanism, and the rear end of the front shaft is connected with a tail cover; the top end of the connecting support plate is connected with a rear shaft which is inserted into the middle bracket; a fairing plate is mounted on the transition surface of the connecting support plate and the rear shaft; the front shaft and the rear shaft form double rotating shafts, the central axis of the front shaft and the central axis of the rear shaft intersect at the rotation center of the model, the intersection angle is fixed when the middle support moves, and the intersection angle value is the maximum sideslip angle of the model. The double-rotating-shaft mechanism for the wind tunnel test is small in structural size, large in output torque, high in positioning precision and capable of continuously, automatically and accurately changing the attitude of an aircraft model, and has engineering practical value.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind tunnel tests, and particularly relates to a double-rotating shaft mechanism for wind tunnel tests. Background Art

[0002] Wind tunnel tests are an important means for the aerodynamic research of aircraft. With the increasing requirements for aircraft maneuverability, during wind tunnel tests, the rolling moment generated by the aircraft model continuously increases; during supersonic tests, during the startup and shutdown processes of a supersonic wind tunnel, the aircraft model bears an impact load far exceeding that during the stable flow field, and the support mechanism must consider the influence of the impact load. At the same time, in order to reduce the interference of the support mechanism on the flow field, a support mechanism with as small a volume as possible is required to adapt to the aerodynamic loads in different states.

[0003] In wind tunnel tests, the double-rotating shaft mechanism is widely used as a support mechanism to simulate the aerodynamic characteristics of an aircraft in different attitudes. Its transmission performance not only directly affects the accuracy of test results but also determines the upper limit of the dynamic test capabilities of the wind tunnel. Currently, some double-rotating shaft mechanisms use complex mechanical structures and large drive units, resulting in a relatively large overall size and difficulty in being integrated into a test environment with a small space, which not only affects the flexibility of the aircraft model layout in the wind tunnel but also increases the test cost. Some other double-rotating shaft mechanisms rely on traditional worm and worm gear transmissions. Although they achieve precise attitude adjustment of the aircraft model and maintain accurate positions through structural self-locking during wind tunnel tests, due to space limitations, the driving method is manual, resulting in low test efficiency. There are also some double-rotating shaft mechanisms that use harmonic reducers and can achieve continuous attitude adjustment of the aircraft model. However, due to the relatively small output torque of harmonic drive, the applicable range of aerodynamic loads is small.

[0004] Currently, there is an urgent need to develop a double-rotating shaft mechanism for wind tunnel tests. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a double-rotating shaft mechanism for wind tunnel tests to overcome the defects of the prior art.

[0006] The double-rotating shaft mechanism for wind tunnel tests of the present invention includes a front shaft, a tail cover, a connecting support plate, a fairing plate, a rear shaft, and a middle support. A Z-shaped connecting support plate is installed above the middle section of the front shaft, and the rear end is connected to the tail cover; the top end of the connecting support plate is connected to the rear shaft, and the rear shaft is inserted into the middle support; a fairing plate is installed on the transition surface between the connecting support plate and the rear shaft. The front shaft and the rear shaft form a double-rotating shaft. The central axis of the front shaft intersects the central axis of the rear shaft at the model rotation center. When the middle support moves, the included angle remains fixed, and the included angle value is the maximum sideslip angle of the model.

[0007] Further, the front axle includes a front drive shaft assembly, a front axle adapter shaft, a front axle reducer, and a front axle drive motor that are sequentially connected; The front axle drive shaft of the front drive shaft assembly is the main shaft; at the front end of the front axle drive shaft, a front axle retaining ring and a front axle flange are sleeved in sequence from the inside to the outside, and the front axle flange is fixed on the connecting support plate by screws evenly distributed along the circumference; in the middle section of the front axle drive shaft, a double-row full complement cylindrical roller bearing I, an angular contact ball bearing I, a front axle oil retaining ring, a front axle bushing, an O-ring, an angular contact ball bearing II, a double-row full complement cylindrical roller bearing II, and a front axle locking nut are sleeved in sequence; the front axle connecting flange is fixed on the front axle locking nut by screws evenly distributed along the circumference; The front end of the front axle adapter shaft is connected to the front axle connecting flange, and the rear end of the front axle adapter shaft is sequentially connected to the front axle reducer, the front axle motor flange, and the front axle drive motor.

[0008] Further, the wind tunnel control system of the double-rotating shaft mechanism is provided with electrical limits and software limits; a removable safety limit block is arranged at the initial zero position of the front axle drive shaft, and the safety limit block is snapped into the stop groove of the front axle drive shaft and fixed on the connecting support plate.

[0009] Further, the rear axle includes a rear drive shaft assembly, a rear axle adapter shaft, a rear axle reducer, and a rear axle drive motor that are sequentially connected; The rear axle drive shaft of the rear drive shaft assembly is the main shaft; at the front end of the rear axle drive shaft, a rear axle retaining ring and a rear axle flange are sleeved in sequence from the inside to the outside; in the middle section of the rear axle drive shaft, a double-row cylindrical roller bearing, a rear axle oil retaining ring, a rear axle locking nut I, a high-pressure locking expansion sleeve, a rear axle bushing, a four-point contact ball bearing, a single-row full complement cylindrical roller bearing, a rear axle locking nut II, and a rear axle connecting flange are sleeved in sequence from front to back close to the rear axle retaining ring; a rear axle sleeve I is sleeved on the double-row cylindrical roller bearing, the rear axle oil retaining ring, the rear axle locking nut I, and the high-pressure locking expansion sleeve; the rear end face of the rear axle flange is connected to the front end face of the rear axle sleeve I, and the contact surface is fixed on the middle support by screws evenly distributed along the circumference; a rear axle sleeve II is sleeved on the rear axle bushing; the rear end face of the rear axle sleeve I is connected to the front end face of the rear axle sleeve II, and the contact surface is connected by screws evenly distributed along the circumference; at the rear end of the rear axle drive shaft, the rear axle adapter shaft, an NGW reducer, an RV reducer, a rear axle motor flange, a rear axle drive motor, and a cover plate are sequentially connected; the cover plate is fixed on the middle support by screws evenly distributed along the circumference.

[0010] Further, both the front axle drive shaft and the rear axle drive shaft are hollow shafts made of 40CrNiMoA forgings, and the central cavity is used for the routing of test cables.

[0011] Furthermore, the front axle reducer of the front axle adopts cycloidal pinwheel RV drive; the NGW reducer of the rear axle adopts NGW planetary gear drive, the RV reducer adopts cycloidal pinwheel RV drive, and the NGW planetary gear drive is in series with the cycloidal pinwheel RV drive.

[0012] Furthermore, zero position scale lines are engraved on the middle support and the connecting support plate, and scale lines are marked on the outer circles of the front axle flange and the rear axle flange as the measurement reference.

[0013] Furthermore, sharp wedges and arc chamfers are provided on the windward surfaces of the middle support and the connecting support plate.

[0014] Furthermore, O-rings are provided between the front axle retaining ring and the front axle flange, the front axle oil retaining ring and the connecting support plate, the front axle connecting flange and the connecting support plate, the rear axle retaining ring and the rear axle flange, the rear axle transmission shaft and the rear axle sleeve II, and the rear axle connecting flange and the middle support.

[0015] The dual-rotating shaft mechanism for wind tunnel tests of the present invention has the following characteristics: a. The blockage ratio of the dual-rotating shaft mechanism in the test section does not exceed 1.5%, and the blockage ratio of the dual-rotating shaft mechanism in the support section does not exceed 5.5%; all components exposed to the airflow have been subjected to smooth transition treatment, and fairing structures such as sharp wedges and arc chamfers are provided on the windward surface, effectively reducing the influence of reverse flow step differences, reducing the interference with the flow field, and improving the accuracy of test data; b. The RV reducer of the rear axle adopts cycloidal pinwheel RV drive, the NGW reducer adopts NGW planetary gear drive, and the NGW planetary gear drive is in series with the cycloidal pinwheel RV drive; the RV sun gear is driven by the rear axle drive motor, transmitted to the cycloidal pinwheel RV through the planet gears and the planet carrier, and then transmitted to the output flange of the cycloidal pinwheel RV. The output flange drives the NGW sun gear through a spline, driving the NGW planetary gear and internal gear ring system, and finally realizing low-speed and high-torque output through the planet carrier; meeting the requirements of small size and high precision, and the entire dual-rotating shaft mechanism can also be continuously and automatically changed through the wind tunnel control system; c. The extension line of the front axle intersects with the extension line of the rear axle at the model rotation center, forming a constant intersection angle, and the intersection angle value is the maximum sideslip angle of the model, ensuring the precise control of the model attitude, and the deviation of the actual measured value of the model sideslip angle is less than 0.05°, meeting the accurate requirements of the wind tunnel test for model attitude adjustment; d. A multiple limit protection mechanism is introduced, including mechanical limit, electrical limit and software limit for three-level protection; a detachable safety limit block is set at the initial zero position. After removing the safety limit block, the wind tunnel control system adopts electrical limit and software limit to ensure that the mechanism can remain stable in any operating state, preventing over-limit movement and potential collision risks.

[0016] The double-rotating shaft mechanism for wind tunnel tests of the present invention has small structural dimensions, large output torque, and high positioning accuracy. It can continuously, automatically, and precisely change the attitude of the aircraft model, and has engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the double-rotating shaft mechanism for wind tunnel tests of the present invention; Figure 2 is an assembly sectional view of the front shaft, tail cover and connecting support plate in the double-rotating shaft mechanism for wind tunnel tests of the present invention; Figure 3 is an assembly sectional view of the rear shaft and the middle support in the double-rotating shaft mechanism for wind tunnel tests of the present invention.

[0018] In the figure, 1. Front shaft; 2. Tail cover; 3. Connecting support plate; 4. Fairing plate; 5. Rear shaft; 6. Middle support; 7. Front shaft transmission shaft; 8. Front shaft retaining ring; 9. Front shaft flange; 10. Double-row full complement cylindrical roller bearing I; 11. Angular contact ball bearing I; 12. Front shaft oil baffle ring; 13. Front shaft bushing; 14. O-ring; 15. Angular contact ball bearing II; 16. Double-row full complement cylindrical roller bearing II; 17. Front shaft locking nut; 18. Front shaft connecting flange; 19. Front shaft adapter shaft; 20. Front shaft motor flange; 21. Front shaft drive motor; 22. Rear shaft transmission shaft; 23. Rear shaft retaining ring; 24. Rear shaft flange; 25. Double-row cylindrical roller bearing; 26. Rear shaft oil baffle ring; 27. Rear shaft locking nut I; 28. High-pressure locking expansion sleeve; 29. Rear shaft sleeve I; 30. Rear shaft sleeve II; 31. Rear shaft bushing; 32. Four-point contact ball bearing; 33. Single-row full complement cylindrical roller bearing; 34. Rear shaft locking nut II; 35. Rear shaft connecting flange; 36. Rear shaft adapter shaft; 37. NGW reducer; 38. RV reducer; 39. Rear shaft motor flange; 40. Rear shaft drive motor; 41. Cover plate. DETAILED DESCRIPTION OF THE INVENTION

[0019] In order to more clearly and elaborately expound the technical solutions and their advantages involved in the embodiments of the present invention, the following will deeply explore the exemplary embodiments of the present invention in combination with specific drawings. It should be noted that the embodiments described herein only constitute a part of the examples of the present invention, not all of them. Based on the embodiments provided herein, all other implementation solutions that can be conceived by those skilled in the art without creative labor should be regarded as within the protection scope of the present invention. In addition, the technical features mentioned in the present invention can be combined with each other under the condition that they do not conflict with each other.

[0020] The double-rotating shaft mechanism for wind tunnel tests of the present invention, as Figure 1 shown, includes a front shaft 1, a tail cover 2, a connecting support plate 3, a fairing plate 4, a rear shaft 5 and a middle support 6; Above the middle section of the front axle 1, a Z-shaped connecting support plate 3 is installed, and the rear end is connected to the tail cover 2; the top end of the connecting support plate 3 is connected to the rear axle 5, and the rear axle 5 is inserted into the middle support 6; a fairing plate 4 is installed on the transition surface between the connecting support plate 3 and the rear axle 5; The front axle 1 and the rear axle 5 form a double rotating shaft, and the central axis of the front axle 1 intersects the central axis of the rear axle 5 at the model rotation center. When the middle support 6 moves, the included angle remains fixed, and the included angle value is the maximum side slip angle of the model.

[0021] Furthermore, as Figure 2 shown, the front axle 1 includes a front drive shaft assembly, a front axle adapter shaft 19, a front axle reducer, and a front axle drive motor 21 connected in sequence; The front drive shaft 7 of the front drive shaft assembly is the main shaft; at the front end of the front drive shaft 7, a front axle retaining ring 8 and a front axle flange 9 are sleeved in sequence from the inside to the outside, and the front axle flange 9 is fixed on the connecting support plate 3 by screws evenly distributed along the circumference; in the middle section of the front drive shaft 7, a double-row full complement cylindrical roller bearing Ⅰ10, an angular contact ball bearing Ⅰ11, a front axle oil baffle ring 12, a front axle bushing 13, an O-ring 14, an angular contact ball bearing Ⅱ15, a double-row full complement cylindrical roller bearing Ⅱ16, and a front axle locking nut 17 are sleeved in sequence; the front axle connecting flange 18 is fixed on the front axle locking nut 17 by screws evenly distributed along the circumference; The front end of the front axle adapter shaft 19 is connected to the front axle connecting flange 18, and the rear end of the front axle adapter shaft 19 is connected to the front axle reducer, the front axle motor flange 20, and the front axle drive motor 21 in sequence.

[0022] Furthermore, the wind tunnel control system of the double rotating shaft mechanism is provided with electrical limits and software limits; a removable safety limit block is set at the initial zero position of the front drive shaft 7, and the safety limit block is clamped into the stop groove of the front drive shaft 7 and fixed on the connecting support plate 3.

[0023] Furthermore, as Figure 3 shown, the rear axle 5 includes a rear drive shaft assembly, a rear axle adapter shaft 36, a rear axle reducer, and a rear axle drive motor 40 connected in sequence; The rear axle drive shaft 22 of the rear drive shaft assembly is the main shaft. At the front end of the rear axle drive shaft 22, a rear axle retaining ring 23 and a rear axle flange 24 are sleeved in sequence from inside to outside. In the middle section of the rear axle drive shaft 22, a double-row cylindrical roller bearing 25, a rear axle oil slinger 26, a rear axle lock nut I 27, a high-pressure locking expansion sleeve 28, a rear axle bushing 31, a four-point contact ball bearing 32, a single-row full complement cylindrical roller bearing 33, a rear axle lock nut II 34, and a rear axle connection flange 35 are sleeved in sequence from front to back close to the rear axle retaining ring 23. A rear axle sleeve I 29 is sleeved on the double-row cylindrical roller bearing 25, the rear axle oil slinger 26, the rear axle lock nut I 27, and the high-pressure locking expansion sleeve 28. The rear end face of the rear axle flange 24 is connected to the front end face of the rear axle sleeve I 29, and the contact surface is fixed on the middle bracket 6 by screws evenly distributed along the circumferential direction. A rear axle sleeve II 30 is sleeved on the rear axle bushing 31. The rear end face of the rear axle sleeve I 29 is connected to the front end face of the rear axle sleeve II 30, and the contact surface is connected by screws evenly distributed along the circumferential direction. At the rear end of the rear axle drive shaft 22, a rear axle adapter shaft 36, an NGW reducer 37, an RV reducer 38, a rear axle motor flange 39, a rear axle drive motor 40, and a cover plate 41 are connected in sequence. The cover plate 41 is fixed on the middle bracket 6 by screws evenly distributed along the circumferential direction.

[0024] Further, both the front axle drive shaft 7 and the rear axle drive shaft 22 are hollow shafts made of 40CrNiMoA forgings, and the central cavity is used for the routing of test cables.

[0025] Further, the front axle reducer of the front axle 1 adopts a cycloid pinwheel RV drive; the NGW reducer 37 of the rear axle 5 adopts an NGW planetary gear drive, the RV reducer 38 adopts a cycloid pinwheel RV drive, and the NGW planetary gear drive and the cycloid pinwheel RV drive are in series.

[0026] Further, zero position scale lines are engraved on the middle bracket 6 and the connecting support plate 3, and scale lines are marked on the outer circles of the front axle flange 9 and the rear axle flange 24 as measurement references.

[0027] Further, pointed wedges and arc chamfers are provided on the windward surfaces of the middle bracket 6 and the connecting support plate 3.

[0028] Further, O-rings 14 are provided between the front axle retaining ring 8 and the front axle flange 9, between the front axle oil slinger 12 and the connecting support plate 3, between the front axle connection flange 18 and the connecting support plate 3, between the rear axle retaining ring 23 and the rear axle flange 24, between the rear axle drive shaft 22 and the rear axle sleeve II 30, and between the rear axle connection flange 35 and the middle bracket 6.

[0029] Example: The test process of the double-rotating shaft mechanism for wind tunnel test in this example is as follows: Before conducting the test, move the dual-rotating shaft mechanism to the preset initial position; during the movement, the running trajectory of the dual-rotating shaft mechanism is only related to the rotation angle δ of the rear shaft and the running angle θ of the machete. When the dual-rotating shaft mechanism is at the initial position (δ = 0, θ = 0), the distance from the nearest point to the cavity body to the center of the rear shaft is 2300 mm, and the distance to the cavity body is 150 mm. This distance is the safety clearance.

[0030] When the middle bracket rotates in the positive direction (downward is positive), the distance between the dual-rotating shaft mechanism and the cavity body gets closer and closer. When the rear shaft rotates, the distance between the dual-rotating shaft mechanism and the cavity body gets farther and farther. To avoid interference between the dual-rotating shaft mechanism and the cavity body, the lift of the rear shaft rotation should be greater than the drop of the middle bracket rotation, that is: 2300×(1 - sin(δ)) ≥ 6000×sin(θ).

[0031] When conducting the test, place the dual-rotating shaft mechanism in the flow field, and change the model attitude by rotating the two rotating shafts of the dual-rotating shaft mechanism around their own axes. The model mainly has three motions: fixing the sideslip angle β and continuously changing the angle of attack α; fixing the angle of attack α and continuously changing the sideslip angle β; fixing the angle of attack α and continuously changing the roll angle γ. Collect the wind tunnel test data under different motion modes until all test objectives are completed.

[0032] Close the wind tunnel, move the dual-rotating shaft mechanism to the preset end position, and the test ends.

Claims

1. A double-rotating shaft mechanism for wind tunnel tests, characterized in that, The described double-rotating shaft mechanism includes a front shaft (1), a tail cover (2), a connecting support plate (3), a fairing plate (4), a rear shaft (5), and a middle support (6); Above the middle section of the front shaft (1), a Z-shaped connecting support plate (3) is installed, and the rear end is connected to the tail cover (2); the top end of the connecting support plate (3) is connected to the rear shaft (5), and the rear shaft (5) is inserted into the middle support (6); a fairing plate (4) is installed on the transition surface between the connecting support plate (3) and the rear shaft (5); The front shaft (1) and the rear shaft (5) form a double-rotating shaft. The central axis of the front shaft (1) intersects the central axis of the rear shaft (5) at the model rotation center. When the middle support (6) moves, the included angle remains fixed, and the included angle value is the maximum sideslip angle of the model.

2. The double-rotating shaft mechanism for wind tunnel test according to claim 1, characterized in that, The described front shaft (1) includes a front drive shaft assembly, a front shaft adapter shaft (19), a front shaft reducer, and a front shaft drive motor (21) connected in sequence; The front shaft drive shaft (7) of the front drive shaft assembly is the main shaft; at the front end of the front shaft drive shaft (7), a front shaft retaining ring (8) and a front shaft flange (9) are sleeved in sequence from the inside to the outside. The front shaft flange (9) is fixed to the connecting support plate (3) by screws evenly distributed along the circumference; in the middle section of the front shaft drive shaft (7), a double-row full complement cylindrical roller bearing I (10), an angular contact ball bearing I (11), a front shaft oil baffle ring (12), a front shaft bushing (13), an O-ring (14), an angular contact ball bearing II (15), a double-row full complement cylindrical roller bearing II (16), and a front shaft locking nut (17) are sleeved in sequence; the front shaft connecting flange (18) is fixed to the front shaft locking nut (17) by screws evenly distributed along the circumference; The front end of the front shaft adapter shaft (19) is connected to the front shaft connecting flange (18), and the rear end of the front shaft adapter shaft (19) is connected to the front shaft reducer, the front shaft motor flange (20), and the front shaft drive motor (21) in sequence.

3. The double-rotating shaft mechanism for wind tunnel test according to claim 2, characterized in that The wind tunnel control system of the described double-rotating shaft mechanism is provided with electrical limits and software limits; a detachable safety limit block is set at the initial zero position of the front shaft drive shaft (7), and the safety limit block is snapped into the stop groove of the front shaft drive shaft (7) and fixed to the connecting support plate (3).

4. The double-rotating shaft mechanism for wind tunnel test according to claim 2, wherein The described rear shaft (5) includes a rear drive shaft assembly, a rear shaft adapter shaft (36), a rear shaft reducer, and a rear shaft drive motor (40) connected in sequence; The rear axle drive shaft (22) of the rear drive shaft assembly is the main shaft; at the front end of the rear axle drive shaft (22), a rear axle retaining ring (23) and a rear axle flange (24) are sleeved in sequence from the inside to the outside; in the middle section of the rear axle drive shaft (22), a double-row cylindrical roller bearing (25), a rear axle oil baffle ring (26), a rear axle locking nut I (27), a high-pressure locking expansion sleeve (28), a rear axle bushing (31), a four-point contact ball bearing (32), a single-row full complement cylindrical roller bearing (33), a rear axle locking nut II (34), and a rear axle connection flange (35) are sleeved in sequence from the front to the rear close to the rear axle retaining ring (23); a rear axle sleeve I (29) is sleeved on the double-row cylindrical roller bearing (25), the rear axle oil baffle ring (26), the rear axle locking nut I (27), and the high-pressure locking expansion sleeve (28); the rear end face of the rear axle flange (24) is connected to the front end face of the rear axle sleeve I (29), and the contact surface is fixed on the middle bracket (6) by screws evenly distributed along the circumference; a rear axle sleeve II (30) is sleeved on the rear axle bushing (31); the rear end face of the rear axle sleeve I (29) is connected to the front end face of the rear axle sleeve II (30), and the contact surface is connected by screws evenly distributed along the circumference; at the rear end of the rear axle drive shaft (22), a rear axle adapter shaft (36), an NGW reducer (37), an RV reducer (38), a rear axle motor flange (39), a rear axle drive motor (40), and a cover plate (41) are connected in sequence; the cover plate (41) is fixed on the middle bracket (6) by screws evenly distributed along the circumference.

5. The double-rotating shaft mechanism for wind tunnel tests according to claim 4, characterized in that, Both the front axle drive shaft (7) and the rear axle drive shaft (22) are hollow shafts made of 40CrNiMoA forgings, and the central cavity is used for the routing of test cables.

6. The double-rotating shaft mechanism for wind tunnel test according to claim 4, wherein, The front axle reducer of the front axle (1) adopts a cycloid pinwheel RV drive; the NGW reducer (37) of the rear axle (5) adopts an NGW planetary gear drive, the RV reducer (38) adopts a cycloid pinwheel RV drive, and the NGW planetary gear drive and the cycloid pinwheel RV drive are in series.

7. The double-rotating shaft mechanism for wind tunnel test according to claim 4, characterized in that Zero position scale lines are engraved on the middle bracket (6) and the connecting support plate (3), and scale lines are marked on the outer circles of the front axle flange (9) and the rear axle flange (24) as the measurement reference.

8. The double-rotating shaft mechanism for wind tunnel test according to claim 4, characterized in that, Sharp wedges and arc chamfers are provided on the windward surfaces of the middle bracket (6) and the connecting support plate (3).

9. The double-rotating shaft mechanism for wind tunnel test according to claim 4, characterized in that, O-ring seals (14) are provided between the front axle retaining ring (8) and the front axle flange (9), the front axle oil baffle ring (12) and the connecting support plate (3), the front axle connection flange (18) and the connecting support plate (3), the rear axle retaining ring (23) and the rear axle flange (24), the rear axle drive shaft (22) and the rear axle sleeve II (30), and the rear axle connection flange (35) and the middle bracket (6).

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