Pitch-variable eVTOL propeller blade and propeller hub connecting structure

Abstract

The utility model provides a variable-pitch eVTOL propeller blade and propeller hub connecting structure, and relates to the field of eVTOL propeller connection. The structure comprises a propeller hub assembly, the propeller hub assembly comprises an upper propeller hub and a lower propeller hub, a propeller root mounting cavity is formed after the upper propeller hub and the lower propeller hub are connected, shaft shoulders are arranged on the inner walls of the upper propeller hub and the lower propeller hub, and limiting steps are arranged at the reference ends of the upper propeller hub and the lower propeller hub; the load bearing structure comprises a pressing plate, a shaft sleeve, an angular contact bearing set and a locking piece, the shaft sleeve and the angular contact bearing set are arranged in the paddle root mounting cavity, the end faces of the two sides of the shaft sleeve make contact with the angular contact bearing set correspondingly, the pressing plate is fixedly connected to the limiting step, and the pressing plate axially limits the angular contact bearing set; and after the propeller root penetrates through the propeller root mounting cavity, the locking piece is used for locking the axial direction of the propeller root. When the structure is used for bearing, a plurality of parts equally share loads at the same time, and the connecting strength is high.

Description

Technical Field

[0001] This utility model relates to the field of eVTOL propeller connection, and more specifically, to a variable pitch eVTOL propeller blade and hub connection structure. Background Technology

[0002] As a key component of vertical takeoff and landing (eVTOL) aircraft, the propeller's structural safety and reliability are paramount requirements for the entire aircraft. The propeller mainly consists of two parts: the blades and the hub. Since most propellers are variable-pitch propellers, meaning the blade angle can be changed in real time according to the aircraft's control system, the connection between the blades and hub must be reliable, safe, and easy to install. Existing variable-pitch propeller blade-hub connection structures mainly rely on relatively complex component structures such as inner and outer cone sleeves, preload nuts, and thrust bearings. These structures are complex to install, have high component manufacturing costs, and exhibit uneven load distribution. The centrifugal load borne by the blades is entirely applied to a single limiting component; if any limiting component fails, the reliability and safety cannot be guaranteed. Utility Model Content

[0003] The purpose of this invention is to provide a variable pitch eVTOL propeller blade and hub connection structure, which solves the problem that the centrifugal load borne by the blade is entirely applied to a single limiting part, thereby improving the reliability and safety of the connection structure.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A variable pitch eVTOL propeller blade-hub connection structure, the structure comprising:

[0006] The propeller hub assembly includes an upper propeller hub and a lower propeller hub. After the upper and lower propeller hubs are connected, a propeller root mounting cavity is formed. Shoulders are provided on the inner walls of the upper and lower propeller hubs. Limiting steps are provided on the reference ends of the upper and lower propeller hubs. The reference end is the side of the propeller root closest to the blade.

[0007] The load-bearing structure includes a pressure plate, a bushing, an angular contact bearing assembly, and a locking element. The bushing and the angular contact bearing assembly are disposed within the propeller root mounting cavity. The two end faces of the bushing are in contact with the angular contact bearing assembly. The pressure plate is fixedly connected to the limiting step and axially limits the angular contact bearing assembly. The angular contact bearing assembly is disposed on both sides of the shaft shoulder. When the propeller root passes through the propeller root mounting cavity, the locking element is used to axially lock the propeller root.

[0008] In this connection structure, to clarify the specific structure of the angular contact bearing assembly, the angular contact bearing assembly includes a first angular contact bearing and a second angular contact bearing. The first angular contact bearing and the second angular contact bearing are respectively connected to both sides of the shaft shoulder, and the first angular contact bearing is set close to the reference end. The pressure plate is fixedly connected to the limiting step and axially limits the first angular contact bearing.

[0009] To ensure more even stress distribution on the locking element and improve the load-bearing capacity and reliability of the connection, the locking element is preferably a double-layered locking nut. This double-nut anti-loosening method allows for adjustment of the preload according to actual needs. Under external forces such as vibration and impact, the interaction between the two nuts effectively resists relative rotation between the threaded pairs, ensuring the reliability and stability of the connection. In load-bearing structures, the double nuts reduce thread contact stress, distributing the load across more thread teeth, resulting in more even stress distribution and improved load-bearing capacity and reliability of the connection.

[0010] In this invention, preferably, the cross-sections of the upper and lower propeller hubs are semi-circular arcs. Aerodynamically, the semi-circular arc shape allows airflow to pass more smoothly, reducing airflow separation and turbulence at the hub and improving the aerodynamic efficiency of the blades. In terms of structural strength, under stress, the force can be evenly distributed across the entire arc-shaped structure of the hub.

[0011] To clarify the connection relationship between this connection structure and the pitch-changing structure, the pitch-changing structure includes a pitch-changing motor, a lead screw, and a guide component;

[0012] The propeller hub assembly includes a hub cover, which is fixedly connected to the top of the upper propeller hub. The variable pitch motor is fixedly connected to the top of the hub cover. The output end of the variable pitch motor is connected to a lead screw, which is connected to the guide member. The guide member is provided with a propeller root pin mounting groove in its circumferential direction. The propeller root is provided with a propeller root pin, which is engaged in the propeller root pin mounting groove and can slide within the propeller root pin mounting groove.

[0013] To reduce sliding friction between the propeller root pin and the propeller root pin mounting groove, the propeller root pin is provided with a propeller pin sleeve and a retaining ring. The propeller pin sleeve is fixedly connected to the outer periphery of the propeller root pin to form a propeller hub. The retaining ring fixes the end of the propeller pin sleeve. The propeller hub is engaged with the propeller root pin mounting groove and slides within the propeller root pin mounting groove.

[0014] In this invention, to enhance pitch-shift linkage detection, the structure includes a displacement sensor and a control system. The displacement sensor is positioned at the top of the propeller hub assembly, and its bottom is used to measure the vertical displacement of the guide member. The control system, displacement sensor, and pitch-shift motor are electrically connected. In this structure, based on the displacement information collected by the displacement sensor, the control system calculates and controls the pitch-shift motor to operate, thereby controlling the pitch position in real time to adjust the blade angle.

[0015] The beneficial effects of this utility model are:

[0016] This structure includes a rotor hub assembly and a load-bearing structure. The rotor hub assembly incorporates shoulders and limiting steps, while the load-bearing structure includes a pressure plate, bushings, angular contact bearing assemblies, and locking components. The bushings effectively distribute the working load across the angular contact bearing assemblies. Simultaneously, the pressure plate, through the limiting steps, axially limits the angular contact bearing assemblies, and the shoulders axially limit the angular contact bearing assemblies on both sides. The locking components lock the axial dimensions of each component, achieving axial locking of the rotor blades. In this connection structure, the load direction is axial centrifugal force towards the rotor tip. The bearings in the angular contact bearing assemblies are installed in the same direction, enabling them to withstand double the axial load in a single direction and bidirectional radial load. After adjusting the preset bearing clearance and radial clearance, each component can bear a portion of the centrifugal load, improving the safety and reliability of the entire connection structure. This connection structure distributes the load evenly among multiple components during load-bearing, resulting in high connection strength and ensuring high reliability and safety. Furthermore, this structure features low component manufacturing costs, a simple structure, and convenient assembly.

[0017] Other features and advantages of this invention will be set forth in the following description, and some will be obvious from the description or may be learned by practicing the embodiments of this invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of this connection.

[0020] Figure 2 This is a schematic diagram of the connection structure between the connection structure and the variable pitch structure;

[0021] Figure 3This is a schematic diagram of the overall structure of the connection structure and the blade.

[0022] Marked in the image:

[0023] 11. Upper propeller hub; 12. Lower propeller hub; 13. Shaft shoulder; 15. Propeller hub cover; 2. Load-bearing structure; 21. Pressure plate; 22. Bushing; 24. Locking element; 231. First angular contact bearing; 232. Second angular contact bearing; 31. Propeller root; 32. Propeller blade; 33. Propeller root pin; 41. Variable pitch motor; 42. Lead screw; 43. Guide element. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to illustrate selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0025] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this utility model, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] Example 1:

[0027] like Figures 1 to 3 As shown, a variable pitch eVTOL propeller blade-hub connection structure includes:

[0028] The propeller hub assembly includes an upper propeller hub 11 and a lower propeller hub 12. After the upper propeller hub 11 and the lower propeller hub 12 are connected, a propeller root mounting cavity is formed. A shoulder 13 is provided on the inner wall of the upper propeller hub 11 and the lower propeller hub 12. A limiting step is provided on the reference end of the upper propeller hub 11 and the lower propeller hub 12. The reference end is the side of the propeller root 31 that is close to the blade 32.

[0029] The load-bearing structure 2 includes a pressure plate 21, a bushing 22, an angular contact bearing assembly, and a locking member 24. The bushing 22 and the angular contact bearing assembly are disposed in the propeller root mounting cavity. The two end faces of the bushing 22 are in contact with the angular contact bearing assembly. The pressure plate 21 is fixedly connected to the limiting step and the pressure plate 21 axially limits the angular contact bearing assembly. The angular contact bearing assembly is disposed on both sides of the shaft shoulder 13. When the propeller root 31 passes through the propeller root mounting cavity, the locking member 24 is used to lock the propeller root 31 axially.

[0030] like Figure 3 The diagram shown is a schematic of the overall structure of this connection structure and the blade 32. The connection is reliable and has strong stability.

[0031] In this connection structure, the introduction of bushing 22 effectively distributes the working load across the angular contact bearing assembly. Simultaneously, pressure plate 21 axially limits the angular contact bearing assembly via a limiting step, and shoulder 13 axially limits the angular contact bearing assemblies on both sides. Locking member 24 locks the blade 32 axially by locking the axial dimensions of each component. In this connection structure, the load direction is axial centrifugal force towards the blade tip. The bearings in the angular contact bearing assembly are installed in the same direction, enabling it to withstand twice the axial load in a single direction and bidirectional radial load. After adjusting the preset bearing clearance and radial clearance, each component can withstand a portion of the centrifugal load, improving the safety and reliability of the entire connection structure.

[0032] In this structure, the blades 32 are made of composite materials and the propeller root 31 is made of metal. When the blades 32 are integrally formed using a special mold, the entire blade structure is safe and reliable, can be mass-produced, and has low overall processing costs. In addition, apart from the standard parts for fixing and the composite blades, the metal materials of the entire structure are mainly made of magnesium alloy, making the overall weight light.

[0033] In this connection structure, to clarify the specific structure of the angular contact bearing assembly, the angular contact bearing assembly includes a first angular contact bearing 231 and a second angular contact bearing 232. The first angular contact bearing 231 and the second angular contact bearing 232 are respectively connected to both sides of the shaft shoulder 13, and the first angular contact bearing 231 is set close to the reference end. The pressure plate 21 is fixedly connected to the limiting step and axially limits the first angular contact bearing 231.

[0034] To clarify the specific structure of the locking component 24, it is described as a double-layered locking nut. This double-nut anti-loosening fixing method allows for adjustment of the preload according to actual needs. When subjected to external forces such as vibration and impact, the interaction between the two nuts effectively resists the relative rotation between the threaded pairs, ensuring the reliability and stability of the connection. In load-bearing structures, the double nuts reduce thread contact stress, distributing the load across more thread teeth, resulting in more uniform thread stress and improved load-bearing capacity and reliability of the connection.

[0035] In this invention, the upper hub 11 and the lower hub 12 have semi-circular cross-sections. Aerodynamically, the semi-circular hub allows for smoother airflow, reducing separation and turbulence at the hub and improving the aerodynamic efficiency of the blade 32. In terms of structural strength, under stress, the force is evenly distributed across the entire arc-shaped structure of the hub, providing better bending resistance compared to other shapes, such as square or rectangular hubs. Furthermore, it effectively resists deformation when bearing the bending moment transmitted by the blade 32, extending the hub's service life.

[0036] like Figure 2 As shown, to clarify the connection relationship between this connection structure and the pitch structure, the pitch structure includes a pitch motor 41, a lead screw 42, and a guide 43;

[0037] The propeller hub assembly includes a hub cover 15, which is fixedly connected to the top of the upper propeller hub 11. The variable pitch motor 41 is fixedly connected to the top of the hub cover 15. The output end of the variable pitch motor 41 is drivenly connected to the lead screw 42. The lead screw 42 is drivenly connected to the guide member 43. The guide member 43 is provided with a propeller root pin mounting groove in its circumferential direction. The propeller root 31 is provided with a propeller root pin 33. The propeller root pin 33 is engaged in the propeller root pin mounting groove and can slide in the propeller root pin mounting groove.

[0038] In the above structure, the guide member 43 is a polygonal structure, and the number of sides of the guide member 43 can be determined according to the number of blades.

[0039] The working principle of this variable pitch structure is as follows: the variable pitch motor 41 outputs a variable pitch force, which is transmitted to the guide member 43 through the lead screw 42. The guide member 43 performs vertical linear motion, thereby driving the blade to perform a variable pitch action.

[0040] To reduce sliding friction between the propeller root pin 33 and the propeller root pin mounting groove, a propeller pin sleeve and a retaining ring are provided on the propeller root pin 33. The propeller pin sleeve is fixedly connected to the outer periphery of the propeller root pin 33 to form a propeller hub. The retaining ring fixes the end of the propeller pin sleeve. The propeller hub is engaged with the propeller root pin mounting groove and slides within the propeller root pin mounting groove.

[0041] In this invention, to enhance pitch-shift linkage detection, a displacement sensor and a control system are included. The displacement sensor is positioned at the top of the propeller hub assembly, and its bottom is used to measure the vertical displacement of the guide member 43. The control system, displacement sensor, and pitch-shift motor 41 are electrically connected. In this structure, based on the displacement information collected by the displacement sensor, the control system calculates and controls the pitch-shift motor 41 to operate, thereby controlling the pitch position in real time to adjust the angle of the propeller blade 32.

[0042] In addition, the control system can directly calculate the pitch angle of the blade based on the rotation angle of the variable pitch motor 41. The bottom of the displacement sensor is used to measure the vertical displacement of the guide member 43. The control system can indirectly calculate the pitch angle of the blade 32 based on the vertical displacement of the guide member 43.

[0043] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0044] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A variable-pitch eVTOL propeller blade and hub connection structure, characterized in that, include: The propeller hub assembly includes an upper propeller hub (11) and a lower propeller hub (12). After the upper propeller hub (11) and the lower propeller hub (12) are connected, a propeller root mounting cavity is formed. A shoulder (13) is provided on the inner wall of the upper propeller hub (11) and the lower propeller hub (12). A limit step is provided on the reference end of the upper propeller hub (11) and the lower propeller hub (12). The reference end is the side of the propeller root (31) near the blade (32). The load-bearing structure (2) includes a pressure plate (21), a bushing (22), an angular contact bearing assembly, and a locking member (24). The bushing (22) and the angular contact bearing assembly are disposed in the propeller root mounting cavity. The two end faces of the bushing (22) are in contact with the angular contact bearing assembly respectively. The pressure plate (21) is fixedly connected to the limiting step, and the pressure plate (21) axially limits the angular contact bearing assembly. The angular contact bearing assembly is disposed on both sides of the shoulder (13). When the propeller root (31) passes through the propeller root mounting cavity, the locking member (24) is used to lock the propeller root (31) axially.

2. The variable pitch eVTOL propeller blade and hub connection structure according to claim 1, characterized in that, The angular contact bearing assembly includes a first angular contact bearing (231) and a second angular contact bearing (232). The first angular contact bearing (231) and the second angular contact bearing (232) are respectively connected to both sides of the shoulder (13), and the first angular contact bearing (231) is set close to the reference end. The pressure plate (21) is fixedly connected to the limiting step and axially limits the first angular contact bearing (231).

3. The variable pitch eVTOL propeller blade and hub connection structure according to claim 1, characterized in that, The locking element (24) is a double-layered locking nut.

4. The variable pitch eVTOL propeller blade and hub connection structure according to claim 1, characterized in that, The cross-sections of the upper rotor hub (11) and the lower rotor hub (12) are semi-circular arcs.

5. A variable pitch eVTOL propeller blade and hub connection structure according to any one of claims 1 to 4, characterized in that, Also includes: A variable pitch structure, the variable pitch structure including a variable pitch motor (41), a lead screw (42) and a guide (43); The propeller hub assembly includes a hub cover (15), which is fixedly connected to the top of the upper propeller hub (11). The variable pitch motor (41) is fixedly connected to the top of the hub cover (15). The output end of the variable pitch motor (41) is connected to the lead screw (42). The lead screw (42) is connected to the guide member (43). The guide member (43) is provided with a propeller root pin mounting groove in the circumferential direction. The propeller root (31) is provided with a propeller root pin (33). The propeller root pin (33) is engaged in the propeller root pin mounting groove and can slide in the propeller root pin mounting groove.

6. The variable pitch eVTOL propeller blade and hub connection structure according to claim 5, characterized in that, The propeller root pin (33) is provided with a propeller pin sleeve and a retaining ring. The propeller pin sleeve is fixedly connected to the outer periphery of the propeller root pin (33) to form a propeller hub. The retaining ring fixes the end of the propeller pin sleeve. The propeller hub is engaged in the propeller root pin mounting groove and slides in the propeller root pin mounting groove.

7. The variable pitch eVTOL propeller blade and hub connection structure according to claim 5, characterized in that, The system includes a displacement sensor and a control system. The displacement sensor is located on the top of the propeller hub assembly, and the bottom of the displacement sensor is used to measure the vertical displacement of the guide (43). The control system, the displacement sensor, and the variable pitch motor (41) are electrically connected.

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