A tiltable propeller device for a tiltrotor aircraft

Abstract

The utility model discloses a kind of liftable propeller devices for tilt-rotor aircraft, it includes mounting bracket, fixed on the mounting bracket and lift driving module, the motor driving module that is driven by lift driving module and moves up and down, the propeller that is driven by motor driving module and rotates and the first shell of fixed setting in mounting bracket periphery. Since tilt-rotor aircraft will experience vertical take-off and landing, transition and cruising three stages in flight process, the height position of propeller and motor driving module in three different stages is adjusted by lift driving module, so that tilt-rotor aircraft maintains good state in stability, lift efficiency, flight economy etc. The utility model cooperates with lift module by control module dynamic adjustment paddle height, so that aircraft maintains good stability, lift efficiency and flight economy in each stage, effectively solve the drawbacks of fixed height design.

Description

Technical Field

[0001] This utility model relates to the field of aircraft, and in particular to a liftable propeller device for tiltrotor aircraft. Background Technology

[0002] Tiltrotor aircraft combine the vertical takeoff and landing capabilities of helicopters with the high-speed cruise capabilities of fixed-wing aircraft. A typical configuration consists of several arms arranged along the wing, with tiltable variable-pitch propellers at the leading end and fixed propellers for vertical lift at the rear. However, this configuration suffers from the following aerodynamic drawbacks: the arms typically house components such as batteries and motors, resulting in relatively thick arm diameters. During vertical takeoff and landing, the thick arms severely obstruct the downwash airflow from the lift propellers, inducing strong vortices and causing fluctuations in propeller thrust, thus significantly reducing lift efficiency and flight stability. During the transition from vertical to horizontal flight, the fixed propeller disk height cannot adapt to the dynamic changes in lift and drag requirements, hindering the smoothness and efficiency of mode transitions. During high-speed cruise, the lift propeller disk exposed to the airflow generates significant parasitic drag, adversely affecting flight speed and energy economy.

[0003] Existing patent CN218594569U discloses a distributed aircraft combining tiltrotor and lift rotor. This solution aims to address the problems of low cruise lift-to-drag ratio and high system complexity associated with pure compound wing systems. It optimizes the aerodynamic layout of the vertical takeoff and landing (VTOL) phase by fixing all rotors and propellers at three different altitudes. Furthermore, it employs a directional locking method for the propellers during the cruise phase to reduce drag. However, this solution uses a layered design with three different propeller altitudes for the VTOL phase. While it addresses the impact of propeller altitude on tiltrotor aircraft, the analysis is insufficient. It only addresses the propeller altitude during VTOL, failing to analyze the transition and cruise phases. Moreover, the three altitudes are fixed presets, lacking dynamic altitude adjustment capabilities. This makes it difficult to adapt to complex and changing flight environments, resulting in limited improvement in lift efficiency.

[0004] Therefore, it is necessary to design a new utility model to solve the above-mentioned technical problems. Utility Model Content

[0005] The main objective of this invention is to provide a liftable propeller device for tiltrotor aircraft. By controlling the lifting module in conjunction with the control module to dynamically adjust the propeller disk height, the aircraft can maintain good stability, lift efficiency and flight economy at all stages, effectively solving the drawbacks of fixed-height design.

[0006] This utility model achieves the above-mentioned objective through the following technical solution: a liftable propeller device for tiltrotor aircraft, comprising: a mounting bracket, a lifting drive module fixed on the mounting bracket, a motor drive module driven by the lifting drive module to move up and down, and a propeller driven by the motor drive module to rotate.

[0007] Furthermore, the mounting bracket has a hollow structure with a vertically connected movable space in the middle, and the motor drive module moves up and down within the movable space to adjust its height.

[0008] Furthermore, the mounting bracket is located at the movable end of the tilting mechanism.

[0009] Furthermore, the mounting bracket includes an upper support, a lower support, and an intermediate support for connecting the upper support and the lower support.

[0010] Furthermore, both the upper support and the lower support are annular plate structures.

[0011] Furthermore, the lifting drive module includes a plurality of lifting drive units arranged in a ring on the mounting bracket.

[0012] Furthermore, the lifting drive unit includes a drive component, a lead screw driven by the drive component to rotate, a guide rod arranged parallel to the lead screw and guiding and constraining the load, a guide block through which the lead screw and the guide rod pass, and a movable mounting plate fixedly connected to the guide block and capable of vertical movement; the motor drive module is fixed on the movable mounting plate.

[0013] Furthermore, the motor drive module includes a second housing, a motor housing disposed within the second housing, a motor module disposed within the motor housing, and a propeller shaft that is driven to rotate by the motor module.

[0014] Furthermore, the propeller is fixed to the propeller shaft; the motor housing is fixed to the movable mounting plate.

[0015] Furthermore, it also includes a first outer casing fixed to the periphery of the mounting bracket.

[0016] Compared with the prior art, the advantages of this utility model for a liftable propeller device for tiltrotor aircraft are as follows: (1) Through the coordinated action of the sensing module, control module and lifting module, the dynamic adaptive adjustment of the rotor disk height in the three stages of vertical take-off and landing, transition and cruise of tiltrotor aircraft is realized, which solves the technical problems of low lift efficiency, large aerodynamic drag and poor flight stability in different flight stages of fixed rotor disk height design. (2) By adopting differentiated altitude adjustment strategies for different flight phases, the propeller disk and the wings and arms were adapted to each other, and the technical problems of airflow obstruction interference in the vertical take-off and landing phase, altitude fluctuation in the transition phase, and large flow resistance in the cruise phase were solved. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the exploded structure of this embodiment; Figure 2 This is a partial three-dimensional structural schematic diagram of this embodiment; Figure 3 This is a three-dimensional structural diagram of the lifting drive unit in this embodiment; The diagram is marked as follows: 100 - Retractable propeller assembly for tiltrotor aircraft; 1- Mounting bracket, 11- Upper support, 12- Lower support, 13- Middle support; 2-Lifting drive module, 21-Lifting drive unit, 211-Drive component, 212-Screw, 213-Guide rod, 214-Guide block, 215-Modible mounting plate; 3-Motor drive module, 31-Second housing, 32-Motor housing, 33-Propeller shaft; 4-Propeller; 5-First outer shell. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to specific embodiments.

[0019] Example: Please refer to Figures 1 to 3 This embodiment provides a liftable propeller device 100 for a tiltrotor aircraft, which includes a mounting bracket 1, a lift drive module 2 fixed on the mounting bracket 1, a motor drive module 3 driven by the lift drive module 2 to move up and down, a propeller 4 driven by the motor drive module 3 to rotate, and a first outer shell 5 fixedly disposed around the mounting bracket 1. Since a tiltrotor aircraft undergoes three phases during flight—vertical takeoff and landing, transition, and cruise—the lift drive module 2 adjusts the height positions of the propeller 4 and the motor drive module 3 at these three different phases, ensuring that the tiltrotor aircraft maintains good stability, lift efficiency, and flight economy.

[0020] A liftable propeller assembly 100 for tiltrotor aircraft is installed at the movable end of the tilt mechanism in the tiltrotor aircraft. During the rotation of the aircraft's propeller, the blade tips rotate to form a propeller disk. Currently, in most tiltrotor aircraft, the height of the propeller disk remains constant during flight. However, this design has the following drawbacks: First, during vertical takeoff and landing (VTOL), the wing severely obstructs and interferes with the downwash flow, creating vortices and reducing lift efficiency. Second, during the transition phase, the aircraft changes from VTOL to cruise mode, during which speed and angle of attack change. If the propeller disk height remains the same as during VTOL, i.e., at a high position, the aircraft will face significant drag, resulting in insufficient cruise speed. If the propeller disk height remains the same as during cruise, i.e., at a low position, speed has not yet fully established, and the lift generated by the wing is insufficient, potentially causing the aircraft to lose altitude. Third, during high-speed cruise, the protruding propeller disk structure introduces additional aerodynamic drag, affecting flight efficiency and range.

[0021] Therefore, it is crucial to dynamically adjust the propeller disk height for different flight stages. In this embodiment, the lifting drive module 2 can achieve adaptive adaptation of the propeller disk height by precisely adjusting the height of the propeller 4 and the motor drive module 3, thus solving the defects of the fixed height design mentioned above.

[0022] The mounting bracket 1 has a hollow structure and a vertically connected movable space in the middle. The motor drive module 3 is fixed in the movable space and moves up and down to adjust its height. It includes an upper support 11 and a lower support 12 with an annular plate shape, as well as a middle support 13.

[0023] The motor drive module 3 includes a second outer shell 31, a motor housing 32 disposed within the second outer shell 31, a motor module (not shown in the figure) disposed within the motor housing 32, and a propeller shaft 33 driven to rotate by the motor module. The motor module is a servo motor adapted to flight vibration and load environments; its core function is to drive the propeller shaft 33 to maintain a stable output speed, ensuring power supply to the propeller 4. The motor housing 32 has an annular fin structure, which can dissipate the heat generated by the motor module during operation, preventing the motor from affecting operational stability due to high-temperature overload. The second outer shell 31 has a cylindrical structure, providing protection for the motor module and the motor housing 32. The propeller 4 is fixedly mounted on the propeller shaft 33, and the motor module drives the propeller shaft 33 to rotate the propeller 4 together.

[0024] The lifting drive module 2 includes a plurality of lifting drive units 21 arranged in a ring on the mounting bracket 1. Each lifting drive unit 21 includes a drive component 211, a lead screw 212 driven by the drive component 211 to rotate, a guide rod 213 arranged parallel to the lead screw 212 and guiding and constraining the load, a guide block 214 through which the lead screw 212 and the guide rod 213 pass, and a movable mounting plate 215 fixedly connected to the guide block 214 and capable of moving up and down. The motor housing 32 of the motor drive module 3 is fixedly mounted on the movable mounting plate 215.

[0025] The working principle is as follows: Through a control algorithm, the optimal height of the propeller disk can be accurately calculated during the three phases of vertical takeoff and landing, transition flight, and cruise for the tiltrotor aircraft. Subsequently, the drive unit 211 receives commands and drives the lead screw 212 to rotate, converting the rotational motion into linear motion. Under the drive of the lead screw 212, the guide block 214 moves stably up and down along the guide rod 213. This motion further drives the motor drive module 3, which is fixed on the movable mounting plate 215, to rise and fall as a whole. Since the propeller 4 is directly mounted on the motor drive module 3, its height is also adjusted synchronously. Ultimately, the system can ensure that the propeller 4 and the motor drive module 3 are always at the optimal height under different flight conditions, thereby comprehensively improving the overall performance of the aircraft.

[0026] CFD-based aerodynamic calculations show that, with a boom diameter of 500mm and a propeller disk diameter of 2.4m, and the initial mounting plane of propeller 4 60mm from the upper surface of the motor, the axial thrust of propeller 4 will be reduced by approximately 6.14% relative to an isolated propeller 4. As the height of propeller 4 increases to 180mm, the thrust loss decreases to approximately 4.22%, exhibiting a near-linear decrease. Therefore, the propeller height can be increased as much as possible during vertical takeoff and landing.

[0027] During forward flight in cruise mode, a higher propeller altitude causes lateral loads on the motor shaft and increases cruise drag. Therefore, it is necessary to minimize altitude, which also reduces drag during cruise. CFD-based aerodynamic calculations show that reducing the distance between the propeller 4 mounting plane and the upper surface of the motor drive module 3 from 180mm to 30mm, under the same calculation conditions, reduces the overall drag coefficient from 0.04937 to 0.04781, demonstrating a significant drag reduction effect.

[0028] The above descriptions are merely some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the concept of this utility model, and all such modifications and improvements fall within the protection scope of this utility model.

Claims

1. A retractable propeller device for a tiltrotor aircraft, characterized in that, It includes: The system comprises a mounting bracket, a lifting drive module fixed on the mounting bracket, a motor drive module that moves up and down driven by the lifting drive module, and a propeller that rotates driven by the motor drive module.

2. The retractable propeller device for a tiltrotor aircraft as described in claim 1, characterized in that: The mounting bracket has a hollow structure with a vertically connected movable space in the middle. The motor drive module can move up and down within the movable space to adjust its height.

3. The retractable propeller device for a tiltrotor aircraft as described in claim 1, characterized in that: The mounting bracket is located at the movable end of the tilting mechanism.

4. The retractable propeller device for a tiltrotor aircraft as described in claim 1, characterized in that: The mounting bracket includes an upper support, a lower support, and an intermediate support for connecting the upper support and the lower support.

5. The retractable propeller device for a tiltrotor aircraft as described in claim 4, characterized in that: Both the upper support and the lower support are annular plate structures.

6. The retractable propeller device for a tiltrotor aircraft as described in claim 1, characterized in that: The lifting drive module includes several lifting drive units arranged in a ring on the mounting bracket.

7. The retractable propeller device for a tiltrotor aircraft as described in claim 6, characterized in that: The lifting drive unit includes a drive component, a lead screw that is driven to rotate by the drive component, a guide rod arranged parallel to the lead screw and guiding and constraining the load, a guide block through which the lead screw and the guide rod pass, and a movable mounting plate fixedly connected to the guide block and capable of moving up and down; the motor drive module is fixed on the movable mounting plate.

8. The retractable propeller device for a tiltrotor aircraft as described in claim 7, characterized in that: The motor drive module includes a second housing, a motor housing disposed within the second housing, a motor module disposed within the motor housing, and a propeller shaft that is driven to rotate by the motor module.

9. The retractable propeller device for a tiltrotor aircraft as described in claim 8, characterized in that: The propeller is fixed to the propeller shaft; the motor housing is fixed to the movable mounting plate.

10. The retractable propeller device for a tiltrotor aircraft as described in claim 1, characterized in that: It also includes a first housing fixed to the periphery of the mounting bracket.

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