In-shaft collective pitch rotor control structure and control method

Abstract

The invention belongs to the field of control mechanism design of vertical take-off and landing aircrafts, and particularly relates to an in-shaft collective pitch rotor control structure and method. Comprising a shifting sleeve fixing nut, an operating rod, a variable-pitch shifting sleeve, a propeller shell, a sliding key, a bearing seat, a double-row angular contact ball bearing, a bearing fixing nut, a steering engine connecting piece, a propeller shell lining, a propeller blade and a variable-pitch rocker arm, and synchronous rotation of the variable-pitch mechanism and the propeller shell is achieved through a guide key. The variable-pitch rocker arm is installed between the variable-pitch shifting sleeve and the paddle, space is fully utilized, and conversion from linear motion of the steering engine to rotary motion of the paddle is achieved. The double-row angular contact bearing is mounted on the operating lever to realize connection with a non-rotating steering engine, pitch variation of five blades can be realized simultaneously, and the operating lever has the advantages of high operating stability, compact structural space and the like.

Description

Technical Field

[0001] The invention belongs to the field of vertical take-off and landing aircraft control mechanism design, and in particular relates to an in-axis collective pitch rotor control structure and a control method. Background Art

[0002] At present, there are huge differences in the eVTOLs on the market in terms of structural appearance, control form, application scenarios, etc. Various units are contending with each other, jointly promoting the rapid development of eVTOL. In terms of control form, the method of providing lift by changing the speed is widely used, and the purpose of aircraft steering is achieved through the speed difference of different rotors. However, this form of control has high requirements for the motor. On the one hand, the motor is restricted by power density and space, and on the other hand, it must provide different speeds according to the requirements of the whole machine. According to the current design capabilities, there are large technical barriers to meeting the requirements of variable speed and high power density at the same time. Therefore, some eVTOLs with simple variable speed on the market have a low flight speed and only realize the function of flying in the air.

[0003] The design of providing lift by changing the collective pitch of the blades is also quite difficult, and the following challenges need to be faced: how to change the pitch of 5 blades at the same time through 1 variable pitch servo; how to change the linear motion of the servo into the rotational motion of 5 blades; how to realize the connection between the rotation of the propeller housing and the non-rotation of the servo in a small space; how to decompose the variable pitch motion and rotational motion, how to realize the relative independence of the components and the maintainability of the equipment; how to meet the functional requirements while having the characteristics of easy installation. Summary of the invention

[0004] Purpose of the invention: To provide an in-axis collective pitch rotor control structure and control method, thereby providing lift by changing the collective pitch of the blades.

[0005] Technical solution:

[0006] A shaft-in-total-pitch rotor control structure comprises: a shift sleeve fixing nut 1, a joystick 2, a pitch shift sleeve 3, a propeller shell 4, a sliding key 5, a bearing seat 6, a double-row angular contact ball bearing 7, a bearing fixing nut 8, a steering gear connecting piece 9, a propeller shell bushing 10, a blade 13, and a pitch shift rocker arm 14, wherein a rocker arm slot is arranged on the outer side of the middle section of the pitch shift sleeve 3, one end of the pitch shift rocker arm 14 is fixed to the blade 13, and the other end of the pitch shift rocker arm 14 is arranged in the rocker arm slot of the pitch shift sleeve 3; the pitch shift rocker arm 14 is driven to rotate by the up and down movement of the pitch shift sleeve 3, so as to realize the conversion from linear motion to rotational motion; the pitch shift sleeve 3 is sleeved on the joystick 2 and is fixed by pressing the shift sleeve fixing nut 1. ; A straight groove is opened at the lower end of the pitch shift sleeve 3, and a sliding key 5 is installed in the straight groove. The inner wall of the lower end of the shaft hole of the paddle housing 4 is provided with a straight groove cooperating with the sliding key 5, which is used to realize the up and down movement of the pitch shift sleeve 3 in the paddle housing 4, and at the same time drive the pitch shift sleeve 3 to rotate with the paddle housing 4; the lower end of the joystick 2 is fixed to the inner ring of the double-row angular contact ball bearing 7, the outer ring of the double-row angular contact ball bearing 7 is fixed to the bearing seat 6, and the bearing seat 6 is connected to the steering gear through the steering gear connecting piece 9, thereby realizing the connection between the steering gear and the paddle housing 4; the inner ring of the fixed double-row angular contact ball bearing 7 rotates with the paddle housing 4, and the outer ring of the double-row angular contact ball bearing 7, the bearing seat 6, and the steering gear connecting piece 9 are relatively fixed and do not rotate.

[0007] Furthermore, the sliding key 5 is fixed to the lower end of the variable pitch sleeve 3 by a sliding key positioning screw 11 .

[0008] Furthermore, a paddle shell bushing 10 is fixed to the lower end of the shaft hole of the paddle shell 4, and the sliding key 5 cooperates with the slotted groove on the inner wall of the paddle shell bushing 10 to realize the up and down movement of the variable pitch sleeve 3 in the paddle shell 4, while driving the variable pitch sleeve 3 to rotate simultaneously with the paddle shell 4.

[0009] Furthermore, the propeller shell bushing 10 is fixed to the propeller shell 4 by means of a propeller shell bushing fixing bolt 12 .

[0010] Furthermore, the lower end of the joystick 2 is fixed to the inner ring of the double-row angular contact ball bearing 7 via a bearing fixing nut 8 .

[0011] Furthermore, the length of the lower groove surface of the rocker arm slot of the variable pitch shift sleeve 3 is smaller than the length of the upper groove surface.

[0012] Furthermore, both ends of the joystick 2 are provided with cross grooves for fixing the joystick 2 when the sleeve fixing nut 1 is tightened.

[0013] A method for controlling an in-axis collective rotor is implemented by means of the in-axis collective rotor control structure described above, and the method comprises:

[0014] Rotational motion process: the motor directly drives the propeller housing 4 to rotate, and the propeller housing 4 directly drives the propeller blade 13, the pitch rocker arm 14, the pitch shift sleeve 3, the joystick 2, and the double-row angular contact ball bearing 7 to rotate;

[0015] Pitch change motion process: the servo directly drives the servo connector 9, the bearing seat 6 and the pitch change sleeve 3 to perform linear motion.

[0016] Beneficial effects:

[0017] The present invention can change the pitch movement of five blades simultaneously through one pitch-changing servo; can change the linear motion of the servo into the rotational motion of five blades; can realize the connection between the rotation of the propeller shell and the non-rotation of the servo in a narrow space; can decompose the pitch movement and the rotational motion to realize the relative independence between the components, and the equipment has maintainability; and has the characteristics of easy installation while meeting the functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of an in-axis collective rotor control structure according to an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the connection between the pitch-changing sleeve and the blade;

[0020] Among them, there are the shift sleeve fixing nut 1, the joystick 2, the pitch shift sleeve 3, the propeller housing 4, the sliding key 5, the bearing seat 6, the double-row angular contact ball bearing 7, the bearing fixing nut 8, the servo connecting part 9, the propeller housing bushing 10, the sliding key positioning screw 11, the propeller housing bushing fixing bolt 12, the blade 13, and the pitch rocker arm 14. DETAILED DESCRIPTION

[0021] The following is a detailed description with reference to the accompanying drawings.

[0022] like Figure 1-2 , an in-axis collective pitch rotor control structure, comprising: a shift sleeve fixing nut 1, a joystick 2, a pitch shift sleeve 3, a propeller shell 4, a sliding key 5, a bearing seat 6, a double-row angular contact ball bearing 7, a bearing fixing nut 8, a steering gear connecting piece 9, a propeller shell bushing 10, a sliding key positioning screw 11, a propeller shell bushing fixing bolt 12, a blade 13, and a pitch rocker arm 14, wherein,

[0023] A rocker slot is provided on the outer side of the middle section of the pitch-changing sleeve 3. The blade 13 and the pitch-changing rocker 14 are fixed by screws. When the blade 13 changes pitch, the pitch-changing rocker 14 rotates at the same time. Specifically, one end of the pitch-changing rocker 14 is fixed to the blade 13, and the other end of the pitch-changing rocker 14 is set in the rocker slot of the pitch-changing sleeve 3. The five pitch-changing rocker arms 14 are directly inserted into the pitch-changing sleeve 3. The pitch-changing rocker arms are driven to rotate by the up and down movement of the pitch-changing sleeve, so as to realize the conversion from linear motion to rotational motion. The pitch-changing sleeve 3 is sleeved on the joystick 2 and is fixed by the sleeve fixing nut 1. A slot is provided at the lower end of the pitch-changing sleeve 3, and a sliding key 5 is installed in the slot. The sliding key 5 is fixed by the positioning screw 11. The lower end of the shaft hole of the propeller shell 4 is fixed with a propeller shell bushing 10. The sliding key 5 cooperates with the slot on the inner wall of the bushing 10 to realize the up and down movement of the pitch-changing sleeve 3 in the propeller shell 4, and at the same time drives the pitch-changing sleeve 3 to rotate with the propeller shell 4. In order to prevent the pitch change sleeve 3 from directly wearing the propeller housing 4, a propeller housing bushing 10 is installed on the propeller housing 4 and fixed with a propeller housing bushing fixing bolt 12. The lower part of the joystick 2 is fixed to the inner ring of the double-row angular contact ball bearing 7, and the outer ring of the double-row angular contact ball bearing 7 is fixed to the bearing seat 6. The bearing seat 6 is connected to the steering gear through the steering gear connector 9, so that the connection between the steering gear and the propeller housing 4 is realized.

[0024] The bearing fixing nut 8 is directly connected to the joystick 2 by threads, and the inner ring of the fixed double-row angular contact ball bearing 7 rotates with the propeller housing 4. The outer ring of the double-row angular contact ball bearing 7, the bearing seat 6, and the steering gear connecting piece 9 are relatively fixed and do not rotate.

[0025] During the actual installation process, the blade 13 and the pitch rocker arm 14 can be assembled separately into a blade assembly; the joystick 2, the double-row angular contact ball bearing 7, and the bearing fixing nut 8 can be assembled separately into an inner control assembly; the sliding key 5, the sliding key fixing screw 11 and the pitch shift sleeve 3 can be assembled separately into an outer control assembly; place one end of the blade assembly on the propeller shell 4, and extend the other end into the inner control assembly to initially realize the pitch change function; extend the inner control assembly into the inner hole of the sleeve 3, and connect it with the sleeve fixing bolt 1, and finally form the entire in-axis collective pitch rotor control structure.

[0026] The control mechanism is decomposed into a propeller housing assembly, an inner control assembly and an outer control assembly. The three assemblies are independent of each other and can be assembled independently at the same time. On the one hand, the assembly efficiency is reduced, and on the other hand, they can be inspected and replaced independently when a fault occurs.

[0027] In actual operation, the shaft-in-column rotor control structure has two degrees of freedom, one is that the control structure rotates with the propeller housing / motor; the other is that the control structure moves with the steering gear in a linear motion to form a variable pitch motion. In the rotational motion, the motor directly drives the propeller housing to rotate, and the propeller housing 4 directly drives the blades 13, the inner control assembly, and the outer control assembly to rotate. Specifically, the motor directly drives the propeller housing 4 to rotate, and the propeller housing 4 directly drives the blades 13, the variable pitch rocker arm 14, the variable pitch shift sleeve 3, the joystick 2, and the double-row angular contact ball bearing 7 to rotate.

[0028] During the pitch-changing motion, the steering gear directly drives the operating assembly to perform linear motion, and the transition between movement and immobility is achieved through the double-row angular contact ball bearing 7. Specifically, the steering gear directly drives the steering gear connecting part 9, the bearing seat 6, and the pitch-changing sleeve 3 to perform linear motion.

[0029] An in-axis collective pitch rotor control structure in the present invention can realize blade pitch change movement, reducing the requirements for motors and flight control. The in-axis collective pitch change mechanism adopts a structure that can realize the pitch change of 5 blades at the same time, and uses guide keys to realize the synchronous rotation of the pitch change mechanism and the propeller shell. A pitch change rocker arm is installed between the pitch change sleeve and the blade to fully utilize the space and realize the conversion of the linear motion of the servo to the rotational motion of the blade. A double-row angular contact bearing is installed on the joystick to realize the connection with the non-rotating servo. At the same time, the built-in joystick also facilitates the installation of the integrated propeller shell / motor. An in-axis collective pitch rotor control structure has the advantages of being able to realize the pitch change of 5 blades at the same time, high operational stability, and compact structural space.

Claims

1. An in-axis collective rotor control structure, characterized in that: include: A shift sleeve fixing nut (1), a control lever (2), a pitch shift sleeve (3), a propeller housing (4), a sliding key (5), a bearing seat (6), a double-row angular contact ball bearing (7), a bearing fixing nut (8), a steering gear connecting piece (9), a propeller housing bushing (10), a propeller blade (13), and a pitch rocker arm (14), wherein: A rocker arm slot is arranged on the outer side of the middle section of the pitch shifting sleeve (3); one end of the pitch shifting arm (14) is fixed to the blade (13), and the other end of the pitch shifting arm (14) is arranged in the rocker arm slot of the pitch shifting sleeve (3); the pitch shifting sleeve (3) is driven to rotate by the up and down movement of the pitch shifting sleeve (3), so as to realize the conversion from linear motion to rotational motion; the pitch shifting sleeve (3) is sleeved on the operating rod (2) and is pressed and fixed by the sleeve fixing nut (1); a slot is opened at the lower end of the pitch shifting sleeve (3), a sliding key (5) is installed in the slot, and a slot matching the sliding key (5) is arranged on the inner wall of the lower end of the shaft hole of the propeller housing (4) , used to realize the up and down movement of the pitch-changing sleeve (3) in the propeller housing (4), and at the same time drive the pitch-changing sleeve (3) to rotate simultaneously with the propeller housing (4); the lower end of the joystick (2) is fixed to the inner ring of the double-row angular contact ball bearing (7), the outer ring of the double-row angular contact ball bearing (7) is fixed to the bearing seat (6), the bearing seat (6) is connected to the steering gear through the steering gear connecting piece (9), and the connection between the steering gear and the propeller housing (4) is realized; the inner ring of the fixed double-row angular contact ball bearing (7) rotates together with the propeller housing (4), and the outer ring of the double-row angular contact ball bearing (7), the bearing seat (6), and the steering gear connecting piece 9 are relatively fixed and do not rotate.

2. The in-axis collective rotor control structure according to claim 1, characterized in that: The sliding key (5) is fixed to the lower end of the pitch-changing sleeve (3) by means of a sliding key positioning screw (11).

3. The in-axis collective rotor control structure according to claim 1, characterized in that: A paddle shell bushing (10) is fixed to the lower end of the shaft hole of the paddle shell (4), and the sliding key (5) cooperates with the slotted groove on the inner wall of the paddle shell bushing (10) to realize the up and down movement of the variable pitch shifting sleeve (3) in the paddle shell 4, and at the same time drives the variable pitch shifting sleeve (3) to rotate simultaneously with the paddle shell 4.

4. The in-axis collective rotor control structure according to claim 3, characterized in that: The propeller shell bushing (10) and the propeller shell (4) are fixed by means of propeller shell bushing fixing bolts (12).

5. The in-axis collective rotor control structure according to claim 1, characterized in that: The lower end of the operating rod (2) is fixed to the inner ring of the double-row angular contact ball bearing (7) via a bearing fixing nut (8).

6. The in-axis collective rotor control structure according to claim 1, characterized in that: The length of the lower groove surface of the rocker arm clamping groove of the variable pitch shifting sleeve (3) is smaller than the length of the upper groove surface.

7. The in-axis collective rotor control structure according to claim 1, characterized in that: Both ends of the operating rod (2) are provided with cross grooves for fixing the operating rod (2) when the sleeve fixing nut (1) is tightened.

8. A method for controlling an in-axis collective rotor, characterized in that: The method is performed by means of an in-axis collective rotor control structure according to any one of claims 1 to 7, and the method comprises: Rotational motion process: the motor directly drives the propeller housing (4) to rotate, and the propeller housing (4) directly drives the propeller blade (13), the pitch-changing rocker arm (14), the pitch-changing sleeve (3), the joystick (2), and the double-row angular contact ball bearing (7) to rotate; Pitch-changing motion process: the steering gear directly drives the steering gear connecting piece (9), the bearing seat (6) and the pitch-changing sleeve (3) to perform linear motion.

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