Simple constant-velocity universal-joint hub for a tilt-rotor aircraft flutter wind-tunnel model

Abstract

The present application belongs to the technical field of wind tunnel test, and discloses a simple constant-speed universal joint hub for a wind tunnel model of a tilt-rotor aircraft, comprising an outer sleeve assembly, an inner hub box assembly, a blade clamp assembly and a power rotating shaft; the outer sleeve assembly connects the inner hub box assembly and the blade clamp assembly; the blade clamp assembly is connected to the outer sleeve assembly through a blade clamp root joint and connected to a rotor blade through a blade clamp. The simple constant-speed universal joint hub of the present application is combined in the form of the outer sleeve assembly and the inner hub box assembly, so that the outer sleeve assembly with the blade clamp assembly installed can tilt in any direction around the rotating shaft. Meanwhile, the output torque of the power rotating shaft can be transmitted. The outer sleeve assembly is detachable in an up-down direction, so that the installation of the simple universal joint hub is convenient and simple. Meanwhile, the blade clamp assembly can be fixed on the outer sleeve through concentric bearings and locking bolts, and can rotate around the rotating shaft. The pitch of the blade clamp and the blades installed on the blade clamp assembly is changed through a variable-pitch rocker arm.

Description

Technical Field

[0001] The invention belongs to the technical field of wind tunnel testing and relates to a simple constant velocity universal hinged propeller hub for a tiltrotor aircraft flutter wind tunnel model. Background Art

[0002] Tiltrotor aircraft developed in recent decades, such as the V22, typically utilize a flap-rigid, constant-velocity universal hinged hub. A unique feature of universal hinged rotor structures is that the blade flapping degrees of freedom are not completely independent; the rigid-body flapping of each blade is determined by the rigid-body motion of the hub. Research results indicate that universal hinged rotors can address the limited stability margins of fully hinged rotors and effectively avoid dynamic instabilities such as "ground resonance" and "air resonance." However, research on the dynamic stability of tiltrotors has primarily focused on spiral flutter, which occurs during aircraft flight mode. Suppressing spiral flutter and increasing flight speed are key challenges in tiltrotor development. Due to the complex structure of the flap-rigid universal hinged hub and the complex aerodynamic characteristics during rotation and forward flight, determining the spiral flutter velocity bounds for tiltrotors through theoretical modeling and simulation analysis is difficult. Wind tunnel testing of spiral flutter of tiltrotor aircraft based on similar models is an important technical approach to solving this problem. However, patent CN201010503188 discloses a constant velocity universal hinged propeller hub for tiltrotor aircraft. This hub is suitable for small tiltrotor aircraft and has a compact structure and high torque transmission. However, its structure is relatively complex and its processing and manufacturing costs are high. The complex components also increase the difficulty of model design and increase nonlinear uncertainties such as clearance and friction, making it difficult to promote and apply in the spiral flutter wind tunnel test model of the model design. Summary of the Invention

[0003] In order to solve the above problems, the present invention proposes a simple universal hinged propeller hub suitable for a spiral flutter wind tunnel test model of a tiltrotor aircraft.

[0004] The technical solution of the present invention:

[0005] A simple constant velocity universal hinged propeller hub for a tiltrotor aircraft flutter wind tunnel model comprises an outer sleeve assembly, an inner hub housing assembly, a blade clamp assembly, and a power shaft. The outer sleeve assembly connects the inner hub housing assembly and the blade clamp assembly. The blade clamp assemblies comprise three components, which are connected to the outer sleeve assembly via blade clamp root joints and to rotor blades via blade clamps. The three blade clamp assemblies are spaced 120 degrees apart.

[0006] The inner hub box assembly comprises a hub box, an inner pin, an inner bearing, an inner bearing seat, an outer pin, an outer bearing, an outer bearing seat, an inner bearing hole and an outer bearing hole; wherein the hub box is a hollow box structure, two opposite faces are provided with an inner bearing hole, two opposite faces are provided with an outer bearing hole, and two opposite faces are also provided with a through hole; one end of the power shaft passes through a through hole and the end is located in another through hole; the inner pin passes through two inner bearing holes and is pressed into the through hole of the power shaft by interference fit, the position of the inner pin pressed into the power shaft is located at the center of the axial direction of the inner pin; the two ends of the inner pin are pressed into the inner bearing, the inner bearing is embedded into the inner bearing hole through the inner bearing seat, the inner pin makes the hub box make inclined motion around the axial direction of the inner bearing, and at the same time, the inner pin can transmit the rotary torque from the power shaft, so that the hub box rotates in the same direction as the power shaft; the outer pin is two, which are in the same horizontal plane and perpendicular to each other; the outer end of the outer pin is pressed into the fixed hole of the outer sleeve assembly, and the inner end of the outer pin is embedded into the inner ring of the outer bearing, while the outer ring of the outer bearing is connected with the outer bearing seat, and the outer bearing seat is embedded into the outer bearing hole; the outer pin makes the hub box make inclined motion around the axial direction of the outer bearing, and at the same time, the outer pin transmits the torque from the hub box to the outer sleeve assembly;

[0007] The outer sleeve assembly is divided into two detachable parts: an upper outer sleeve and a lower outer sleeve, and a fixed hole into which the outer end of the outer pin is pressed is left between the two; the outer sleeve assembly comprises an upper outer sleeve, a lower outer sleeve, an upper and lower outer sleeve locking bolt, an upper and lower outer sleeve locking bolt hole and a vane clamp assembly mounting hole; wherein the upper outer sleeve and the lower outer sleeve are locked by the upper and lower outer sleeve locking bolt passing through the upper and lower outer sleeve locking bolt hole; the outer sleeve assembly is provided with a vane clamp assembly mounting hole every 120°, which is used for mounting a vane clamp assembly;

[0008] The outer sleeve assembly can make inclined motion around the axial direction of the outer bearing relative to the inner hub box assembly, the hub box in the inner hub box assembly can make inclined motion around the axial direction of the inner bearing, and the directions of the two inclined motions are perpendicular to each other, so that the outer sleeve assembly can be inclined in any direction; at the same time, there is a gap between the outer sleeve assembly and the lower part of the power shaft, which provides space for the inclination of the inclination direction of the vane, and at the same time, the angle of the simulation paddle inclination can be infinitely large.

[0009] The blade clamp assembly includes a blade clamp root joint, a blade clamp root bearing, a blade clamp tip bearing, a blade clamp root bearing, a blade clamp tip bearing, a gasket, a locking bolt, a blade clamp and a pitch rocker arm; the blade clamp root joint of the blade clamp assembly is connected to the blade clamp assembly mounting hole of the outer sleeve assembly, so that the blade clamp assembly rotates together with the outer sleeve assembly; the blade clamp is fixed to the blade clamp root joint by a concentric blade clamp root bearing, a blade clamp tip bearing, a gasket and a locking bolt, wherein the blade clamp root bearing is installed at the blade clamp root The blade clamp tip bearing is installed on the blade clamp tip bearing position; the concentric blade clamp root bearing and blade clamp tip bearing provide the blade clamp with rotational freedom around the axial direction of the blade clamp root joint. At the same time, the blade clamp is provided with a pitch rocker arm, which is connected to the push-pull rod, and the pitch rocker arm is pushed by the push-pull rod to make the blade clamp rotate around the blade clamp root joint; the locking bolt passes through the gasket and is connected to the blade clamp root joint, which plays the role of locking the blade clamp, so that the blade clamp is fixed in the axial direction and can rotate around the bearing at the same time.

[0010] Beneficial effects of the present invention: The present invention simplifies the structure of a simple universal hinge hub. Through the combination of an outer sleeve assembly and an inner wheel box assembly, the outer sleeve assembly equipped with a blade clamp assembly can be tilted in any direction around the rotating shaft. At the same time, the output torque of the power shaft can be transmitted. The outer sleeve assembly is made detachable up and down, which can facilitate the installation of the simple universal hinge hub. At the same time, the blade clamp assembly can be fixed to the outer sleeve by concentric bearings and locking bolts, and can be rotated around the rotating shaft. The pitch of the blade clamp and the blades installed on the blade clamp assembly is changed by a pitch rocker arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of a simple universal hinge hub device;

[0012] Figure 2 This is a detailed structural diagram of the inner hub box assembly;

[0013] Figure 3 It is a detailed diagram of the domestic and foreign sales structure;

[0014] Figure 4 This is a detailed structural diagram of the outer sleeve assembly;

[0015] Figure 5 This is a detailed diagram of the blade clamp assembly structure;

[0016] Figure 6 This is a schematic diagram of the paddle disc waving.

[0017] In the figure: 1 outer sleeve assembly, 2 inner hub box assembly, 3 blade clamp assembly, 4 power shaft, 11 outer sleeve upper part, 12 outer sleeve lower part, 13 outer sleeve upper and lower locking bolts, 14 outer sleeve upper and lower locking bolt holes, 15 blade clamp assembly mounting hole, 21 hub box, 22 inner pin, 23 inner bearing, 24 inner bearing seat, 25 outer pin, 26 outer bearing, 27 outer bearing seat, 28 inner bearing hole, 29 outer bearing hole, 31 blade clamp root joint, 32 blade clamp root bearing position, 33 blade clamp tip bearing position, 34 blade clamp root bearing, 35 blade clamp tip bearing, 36 gasket, 37 locking bolt, 38 blade clamp, 39 pitch rocker arm, θ propeller disc inclination angle. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0019] Example 1: Installation method

[0020] The present invention provides a simple universal hinge hub device suitable for a tiltrotor aircraft spiral flutter wind tunnel test model, such as Figure 1 As shown, it includes an outer sleeve assembly 1, an inner hub box assembly 2, a blade clamp assembly 3, and a power shaft 4.

[0021] Figure 1 In the embodiment, the blade clamp assembly 3 is connected to the outer sleeve assembly 1 via the blade clamp root joint 31 , three blade clamp assemblies 3 are connected to three rotor blades, and the angle between the three blade clamp assemblies 3 is 120°.

[0022] Figure 2 In the figure, the inner hub housing assembly 2 comprises a hub housing 21, an inner pin 22, an inner bearing 23, an inner bearing seat 24, an outer pin 25, an outer bearing 26, an outer bearing seat 27, an inner bearing hole 28, an outer bearing hole 29, and a power shaft 4. The inner pin 22 is press-fitted into the power shaft 4 through an interference fit, positioned axially in the middle of the inner pin 22. The inner pin 22 is then pressed into the inner bearing 23, which is then inserted into the inner bearing hole 28 via the inner bearing seat 24. The inner pin 22 enables the hub housing 21 to swing axially about the inner bearing 23 while also transmitting rotational torque from the power shaft 4, allowing the hub housing 21 to rotate in the direction of rotation of the power shaft 4. The outer end of the outer pin 25 is pressed into the outer sleeve assembly 1, while the inner end of the outer pin 25 is inserted into the inner ring of the outer bearing 26. The outer ring of the outer bearing 26 is connected to the outer bearing seat 27, which is then inserted into the outer bearing hole 29. The outer pin 25 enables the hub housing 21 to swing axially around the outer bearing 26 , while transmitting the torque of the hub housing 21 to the outer sleeve assembly 1 .

[0023] Figure 3In the middle, the inner pin 22 is pressed into the power shaft 4, and the pressing position is located in the middle of the axial direction of the inner pin 22. The inner bearing 23 is installed at point a of the inner pin 22, and the inner bearing 23 is embedded in the inner bearing seat 24, and the inner bearing seat 24 is installed on the inner bearing hole 28 of the hub box 21. The power shaft 4 transmits the rotary torque to the hub box 21 through the inner pin 22, and releases the rotary freedom of the hub box 21 around the inner bearing 23 through the inner bearing 23, so that the hub can tilt around the axis direction of the inner bearing 23. The outer pin 25 connects the hub box 21 and the outer sleeve assembly 1, the outer bearing 26 is installed at point b of the outer pin 25, and is embedded in the outer bearing seat 27, and the outer bearing seat 27 is installed on the outer bearing hole 29 of the hub box 21. The outer pin 25 transmits the rotary torque from the hub box 21 to the outer sleeve assembly 1, and finally to the blade clamp assembly 3 and the rotor blade. The outer bearing 26 releases the rotary freedom between the hub box 21 and the outer sleeve assembly 1 around the axis direction of the outer bearing 26, so that the hub can tilt along the axis direction of the outer bearing 26. The inner pin 22, the inner bearing 23, the hub box 21, the outer pin 25 and the outer bearing 26 form a universal hinge structure, so that the hub can tilt in any direction around the end of the power shaft, as shown in Figure 6 .

[0024] Figure 4 In the middle, the outer sleeve assembly 1 connects the inner hub box assembly 2 and the blade clamp assembly 3. In order to facilitate disassembly and assembly, the outer sleeve assembly 1 is detachable in upper and lower parts, and the outer sleeve assembly 1 comprises: an outer sleeve upper part 11, an outer sleeve lower part 12, an outer sleeve upper and lower part locking bolt 13, an outer sleeve upper and lower part locking bolt hole 14, and a blade clamp assembly mounting hole 15. Among them, the outer sleeve upper part 11 and the outer sleeve lower part 12 are locked by the outer sleeve upper and lower part locking bolt 13 through the outer sleeve upper and lower part locking bolt hole 14. The outer sleeve assembly 1 is provided with blade clamp assembly mounting holes 15 every 120°, which are used to install the blade clamp assembly 3.

[0025] The outer sleeve assembly 1 can tilt around the axis direction of the outer bearing 26 relative to the inner hub box assembly 2, and at the same time, the hub box 21 in the inner hub box assembly 2 can swing around the axis direction of the inner bearing 23. At the same time, the axes of the tilt direction and the swing direction are perpendicular to each other, and finally the outer sleeve assembly 1 can tilt in any direction, as shown in Figure 6 . At the same time, there is a gap between the inner ring of the lower end surface of the outer sleeve assembly 1 and the power shaft 4, which provides space for the tilt of the blade in the direction, and at the same time can simulate the angle of the tilt of the rotor disc to be infinite.

[0026] Figure 5 In the middle, the blade clamp assembly 3 comprises: a blade clamp root joint 31, a blade clamp root bearing position 32, a blade clamp tip bearing position 33, a blade clamp root bearing 34, a blade clamp tip bearing 35, a gasket 36, a locking bolt 37, a blade clamp 38, and a variable pitch rocker arm 39. Figure 5The blade clamp root joints 31 of the three blade clamp assemblies 3 shown in the figure are connected to the blade clamp assembly mounting holes 15 of the outer sleeve assembly 1, allowing the blade clamp assemblies 3 to rotate together with the outer sleeve assembly 1. The blade clamp 38 is fixed to the blade clamp root joint 31 by two concentric blade clamp root bearings 34, a blade clamp tip bearing 35, a gasket 36, and a locking bolt 37. The blade clamp root bearing 34 is mounted on the blade clamp root bearing position 32, and the blade clamp tip bearing 35 is mounted on the blade clamp tip bearing position 33. The two concentric blade clamp root bearings 34 and blade clamp tip bearings 35 provide the blade clamp 38 with rotational freedom around the axial direction of the blade clamp root joint 31. At the same time, the pitch rocker arm 39 is connected to the push-pull rod, which can push the pitch rocker arm 39 by pushing and pulling the rod, allowing the blade clamp 38 to rotate around the blade clamp root joint 31. The locking bolt 37 passes through the gasket 36 and is connected to the blade clamp root joint 31, which plays the role of locking the blade clamp 38, so that the blade clamp 38 is fixed in the axial direction and can rotate around the bearing.

[0027] Example 2: Usage

[0028] Step 1: Connect the external power to the power shaft 4. The power shaft 4 transmits the rotational torque to the inner hub box assembly 2 through the inner pin 22. The inner hub box assembly 2 further transmits the torque to the outer sleeve assembly 1 through the outer pin 25, and finally drives the blade clamp assembly 3 and the rotor blade to rotate together.

[0029] Step 2: Through the inner bearing 23 and the outer bearing 26, the outer sleeve assembly 1 can be tilted in any direction.

[0030] Step 3: By pushing the pitch rocker arm 39 of the blade clamp assembly 3 through the push-pull rod, the blade clamp 38 can be rotated around the axis of the blade clamp root joint 31, thereby achieving continuous pitch change during the experiment.

Claims

1. A simple constant velocity universal hinged propeller hub for a tiltrotor aircraft flutter wind tunnel model, characterized in that: The tiltrotor flutter wind tunnel model uses a simple constant velocity universal hinged hub comprising an outer sleeve assembly (1), an inner hub box assembly (2), a blade clamp assembly (3) and a power shaft (4); the outer sleeve assembly (1) realizes the connection between the inner hub box assembly (2) and the blade clamp assembly (3); there are three blade clamp assemblies (3), which are connected to the outer sleeve assembly (1) through a blade clamp root joint (31) and connected to the rotor blade through a blade clamp (38), and the angle between the three blade clamp assemblies (3) is 120 degrees; The outer sleeve assembly (1) performs a tilting motion relative to the inner hub housing assembly (2) around the axis of the outer bearing (26), and the hub housing (21) in the inner hub housing assembly (2) performs a tilting motion around the axis of the inner bearing (23), and the directions of the two tilting motions are perpendicular to each other, so that the outer sleeve assembly (1) can tilt in any direction; at the same time, there is a gap between the outer sleeve assembly (1) and the lower part of the power shaft (4), which provides space for the tilting direction of the blade and prevents the propeller disc from tilting at an infinite angle.

2. The simple constant velocity universal hinged propeller hub for a tiltrotor aircraft flutter wind tunnel model according to claim 1, characterized in that: The inner hub box assembly (2) includes a hub box (21), an inner pin (22), an inner bearing (23), an inner bearing seat (24), an outer pin (25), an outer bearing (26), an outer bearing seat (27), an inner bearing hole (28) and an outer bearing hole (29); wherein the hub box (21) is a hollow box structure, with inner bearing holes (28) opened on the left and right opposite surfaces, outer bearing holes (29) opened on the front and rear opposite surfaces, and through holes opened on the upper and lower opposite surfaces; one end of the power shaft (4) passes through a through hole, and the end is located in the other through hole; the inner pin (22) passes through the two inner bearing holes (28) and is pressed into the through hole of the power shaft (4) by interference fit, and the position where the inner pin (22) is pressed into the power shaft (4) is located at the axial center of the inner pin (22); the two ends of the inner pin (22) are respectively pressed into the inner bearing (23), and the inner bearing (23) is pressed into the through hole of the power shaft (4) by the inner bearing seat (24) is embedded in the inner bearing hole (28), and the inner pin (22) causes the hub box (21) to tilt around the axis of the inner bearing (23), and at the same time can transmit the rotational torque from the power shaft (4), so that the hub box (21) rotates along the rotation direction of the power shaft (4); there are two outer pins (25), which are on the same horizontal plane as the inner pin (22) and are perpendicular to each other; the outer end of the outer pin (25) is pressed into the fixing hole of the outer sleeve assembly (1), and the inner end of the outer pin (25) is embedded in the inner ring of the outer bearing (26), and at the same time the outer ring of the outer bearing (26) is connected to the outer bearing seat (27), and the outer bearing seat (27) is embedded in the outer bearing hole (29); the outer pin (25) causes the hub box (21) to tilt around the axis of the outer bearing (26), and at the same time transmits the torque of the hub box (21) to the outer sleeve assembly (1).

3. The simple constant velocity universal hinge hub for a tiltrotor aircraft flutter wind tunnel model according to claim 2, characterized in that: The outer sleeve assembly (1) is divided into two detachable parts: an outer sleeve upper part (11) and an outer sleeve lower part (12), with a fixing hole for pressing the outer end of the outer pin (25) therebetween; the outer sleeve assembly (1) comprises an outer sleeve upper part (11), an outer sleeve lower part (12), outer sleeve upper and lower locking bolts (13), outer sleeve upper and lower locking bolt holes (14) and blade clamp assembly mounting holes (15); wherein, the outer sleeve upper part (11) and the outer sleeve lower part (12) are locked by the outer sleeve upper and lower locking bolts (13) passing through the outer sleeve upper and lower locking bolt holes (14); the outer sleeve assembly (1) is provided with blade clamp mounting holes (15) every 120° for mounting the blade clamp assembly (3).

4. The simple constant velocity universal hinged propeller hub for a tiltrotor aircraft flutter wind tunnel model according to claim 3, characterized in that: The blade clamp assembly (3) comprises a blade clamp root joint (31), a blade clamp root bearing position (32), a blade clamp tip bearing position (33), a blade clamp root bearing (34), a blade clamp tip bearing (35), a gasket (36), a locking bolt (37), a blade clamp (38) and a pitch rocker arm (39); the blade clamp root joint (31) of the blade clamp assembly (3) is connected to the blade clamp assembly mounting hole (15) of the outer sleeve assembly (1), so that the blade clamp assembly (3) and the outer sleeve assembly (1) rotate together; the blade clamp (38) is fixed to the blade clamp root joint (31) through the concentric blade clamp root bearing (34), the blade clamp tip bearing (35), the gasket (36) and the locking bolt (37), wherein the blade clamp root bearing (34) is installed The blade clamp (38) is mounted on the blade clamp root bearing position (32), and the blade clamp tip bearing (35) is mounted on the blade clamp tip bearing position (33); the concentric blade clamp root bearing (34) and the blade clamp tip bearing (35) provide the blade clamp (38) with the axial rotational freedom around the blade clamp root joint (31); at the same time, the blade clamp (38) is provided with a pitch rocker arm (39), which is connected to the push-pull rod. The pitch rocker arm (39) is pushed by the push-pull rod to make the blade clamp (38) rotate around the blade clamp root joint (31); the locking bolt (37) passes through the gasket (36) and is connected to the blade clamp root joint (31), playing the role of locking the blade clamp (38), so that the blade clamp (38) is fixed in the axial direction and the blade clamp (38) can be rotated around the bearing.

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