An aircraft variable pitch propeller mounting assembly
By using needle roller bearings and wear-resistant rings in the variable pitch blade mounting assembly to optimize the force at the blade root, combined with tapered sleeve threaded connections, the problem of uneven connection between the blade and the hub was solved, achieving higher assembly accuracy and reduced costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO XINTAI MACHINERY
- Filing Date
- 2025-05-21
- Publication Date
- 2026-06-30
Smart Images
Figure CN224427783U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of low-altitude flight technology, specifically relating to an aircraft variable-pitch propeller mounting assembly. Background Technology
[0002] Aircraft propellers are a key component of aviation propulsion systems, generating thrust or pull through rotation to propel aircraft forward. Based on their design characteristics and application scenarios, propellers can be categorized into different types, such as fixed-pitch propellers, variable-pitch propellers, and reversible-pitch propellers. With the development of the aviation industry, the demand for high-performance, high-efficiency propeller systems is increasing. In various applications, variable-pitch propellers have become a key component because they can automatically adjust the blade angle according to flight conditions, thereby optimizing aerodynamic performance and range. The variable-pitch function is achieved by changing the angle between the propeller blades and the rotation axis, allowing the propeller to provide optimal thrust or pull at different stages of flight. Besides traditional fixed-wing aircraft and helicopters, variable-pitch propellers also have broad application prospects in emerging eVTOL (electric vertical takeoff and landing) aircraft and long-endurance unmanned aerial vehicles (UAVs). These new aircraft need to efficiently switch between different flight modes (such as vertical takeoff / landing, cruise flight, etc.), thus placing higher demands on the multi-functionality and flexibility of propellers. First, most existing propeller blades are made of carbon fiber composite materials, while the hub is made of metal. Generally, a metal jacket is placed over the root of the composite blade before it is assembled with the hub. The connection between the metal jacket and the composite blade is mainly achieved by curing the whole piece in a furnace. Considering the different material changes of the two materials when heated and pressurized in the furnace, the laying of the composite material and the assembly of the metal parts involve many design, process and assembly details, resulting in extremely high propeller costs and potential problems in actual production and later maintenance. Second, in the existing variable pitch propeller mounting components, the radial load mainly relies on a single angular contact bearing or needle roller bearing to transmit the torque to the hub, resulting in uneven load distribution. Currently, the propeller bushing does not have a direct installation and locking structure, making installation inconvenient, making it impossible to directly confirm the installation torque, and resulting in low installation accuracy and efficiency. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide an aircraft variable pitch blade mounting assembly that is more balanced in terms of force, optimizes the force on the blade root and blade hub, simplifies the assembly process, and improves the assembly accuracy, in light of the current state of the technology.
[0004] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: an aircraft variable pitch blade mounting assembly, characterized in that it includes a blade, a blade mounting sleeve, a blade pressure sleeve, a blade cone sleeve, and a variable pitch cam. The blade cone sleeve covers the root of the blade and is fixed inside the blade mounting sleeve by connecting the blade pressure sleeve and the blade mounting sleeve. The variable pitch cam is fixed on the tail of the blade mounting sleeve. The blade mounting sleeve has a stepped surface, and a needle roller bearing for transmitting the root bending moment and a wear-resistant ring are installed on the stepped surface.
[0005] As a further optimization, in the aforementioned aircraft variable pitch blade mounting assembly, the needle roller bearing is divided into a needle roller radial bearing and a needle roller axial bearing. The needle roller radial bearing is installed on the right step surface of the blade mounting sleeve, and the inner ring of the needle roller radial bearing mates with the right step surface of the blade mounting sleeve. The needle roller axial bearing is installed on the left step surface of the blade mounting sleeve, and the right ring of the needle roller axial bearing mates with the left step surface of the blade mounting sleeve.
[0006] Here, the inner ring of the needle roller radial bearing mates with the right stepped surface of the blade mounting sleeve primarily to transmit the radial load at the root of the blade, while the right ring of the needle roller axial bearing mates with the left stepped surface of the blade mounting sleeve primarily to transmit the axial load at the root of the blade.
[0007] As a further optimization, in the above-mentioned aircraft variable pitch blade mounting assembly, the wear ring has a blade mounting nut, the wear ring is stuck in the inner groove of the blade mounting nut, the blade mounting nut abuts against the left ring of the needle roller axial bearing along the left stepped surface of the blade mounting sleeve, and the wear ring and the blade mounting sleeve slide against each other and bear their radial load.
[0008] As a further optimization, in the above-mentioned aircraft variable pitch blade mounting assembly, the blade cone sleeve consists of two pieces that cover the root of the blade, and the root of the blade passes through the inner hole of the blade sleeve.
[0009] As a further optimization, in the aforementioned aircraft variable pitch blade mounting assembly, two blade cone sleeves are symmetrically fitted onto the corresponding inclined surfaces at the root of the blade, and the blade and blade cone sleeves are fixed inside the blade mounting sleeve by a threaded connection between the blade pressure sleeve and the blade mounting sleeve.
[0010] As a further optimization, in the above-mentioned aircraft variable pitch rotor blade mounting assembly, the variable pitch cam is provided with a variable pitch block, a variable pitch pin, and a shaft elastic washer. The variable pitch block is fixed to the variable pitch cam by the variable pitch pin and the shaft elastic washer, and the variable pitch cam rotates around the axis when the variable pitch block moves up and down due to the eccentricity of the variable pitch block relative to the axis of the variable pitch cam.
[0011] As a further optimization, in the aforementioned aircraft variable pitch blade mounting assembly, the variable pitch cam has a connector, and the variable pitch cam is fixed to the blade mounting sleeve by means of a threaded connection through the connector.
[0012] As a further optimization, in the aforementioned aircraft variable pitch blade mounting assembly, a locking element is provided on the outer ring of the blade sleeve, and the blade sleeve is locked by the locking element.
[0013] Compared with the prior art, the advantages of this utility model are that the bending moment at the blade root is transmitted through a wear-resistant ring and a needle roller bearing, which results in a more balanced force transmission than the existing force transmission method of a single needle roller bearing, thus optimizing the force situation at the blade root and the blade hub. Four tool mating surfaces are evenly distributed on the blade sleeve, which makes it convenient to directly confirm the installation torque using the corresponding tools. Compared with the traditional method of externally attaching installation tools by opening holes around the perimeter, this simplifies the assembly process and improves the assembly accuracy. In addition, the traditional one-piece solidification process of the blade root metal sleeve is eliminated and replaced with a tapered sleeve threaded clamping structure that is easier to process and assemble, which greatly reduces production costs and assembly difficulty. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the variable pitch rotor blade mounting assembly structure of this aircraft;
[0015] Figure 2 This is a schematic diagram of the internal cross-sectional structure of the variable pitch rotor blade mounting assembly of this aircraft.
[0016] Figure 3 This is a three-dimensional structural diagram of the variable pitch propeller blade mounting assembly of this aircraft. Detailed Implementation
[0017] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.
[0018] In the diagram, blade 100; blade mounting sleeve 200; blade pressure sleeve 300; blade cone sleeve 400; pitch cam 500; locking element 600; needle roller radial bearing 700; needle roller axial bearing 800; wear ring 900; blade mounting nut 1000; pitch block 1001; pitch pin 1002; shaft elastic washer 1003; and connector 1004.
[0019] like Figure 1 and Figure 3As shown, the variable-pitch rotor blade mounting assembly of this aircraft includes a rotor blade 100, a rotor blade mounting sleeve 200, a rotor blade retaining sleeve 300, a rotor blade cone sleeve 400, and a variable-pitch cam 500. To facilitate the installation of the entire rotor blade 100, the rotor blade cone sleeve 400 in this patent covers the root of the rotor blade 100, and the rotor blade 100 and rotor blade cone sleeve 400 are fixed within the rotor blade mounting sleeve 200 by connecting the rotor blade retaining sleeve 300 to the rotor blade mounting sleeve 200. The rotor blade cone sleeve 400 consists of two pieces and covers the root of the rotor blade 100. The root of the rotor blade 100 passes through the inner hole of the rotor blade retaining sleeve 300. Figure 2 as well as Figure 1 As shown, the specific optimization here is to symmetrically fit two blade cone sleeves 400 onto the corresponding inclined surface at the root of the blade 100, and fix the blade 100 and blade cone sleeves 400 inside the blade mounting sleeve 200 through the threaded connection between the blade pressure sleeve 300 and the blade mounting sleeve 200, ensuring that there is no relative movement between the blade 100 and the blade mounting sleeve 200. A locking member 600 is provided on the outer ring of the blade pressure sleeve 300, and the blade pressure sleeve 300 is locked by the locking member 600 to prevent loosening.
[0020] One innovation of this patent is the optimization of the stress distribution at the root of the blade 100 and the blade hub. The blade mounting sleeve 200 has a stepped surface, on which a needle roller bearing for transmitting the root bending moment and a wear ring 900 are installed. The needle roller bearing consists of a radial needle roller bearing 700 and an axial needle roller bearing 800. The radial needle roller bearing 700 is installed on the right stepped surface of the blade mounting sleeve 200, and its inner ring mates with the right stepped surface of the blade mounting sleeve 200. The axial needle roller bearing 800 is installed on the left stepped surface of the blade mounting sleeve 200, and its right ring mates with the left stepped surface of the blade mounting sleeve 200. The inner ring of the radial needle roller bearing 700... The engagement between the right ring of the wear ring and the right stepped surface of the blade mounting sleeve 200 is mainly used to transmit the radial load at the root of the blade. The engagement between the right ring of the needle roller axial bearing 800 and the left stepped surface of the blade mounting sleeve 200 is mainly used to transmit the axial load at the root of the blade 100. In addition, the wear ring 900 has a blade mounting nut 1000. The wear ring 900 is stuck in the inner groove of the blade mounting nut 1000. The blade mounting nut 1000 presses against the left ring of the needle roller axial bearing 800 along the left stepped surface of the blade mounting sleeve 200. The wear ring 900 and the blade mounting sleeve 200 slide against each other and bear their radial load. In this way, the force balance at the root of the blade 100 is optimized by using the wear ring 900 and the needle roller bearing as force transmission components.
[0021] In addition, to achieve pitch variation, the pitch cam 500 is fixed to the tail of the blade mounting sleeve 200. The pitch cam 500 is provided with a pitch block 1001, a pitch pin 1002, and a shaft elastic washer 1003. The pitch block 1001 is fixed to the pitch cam 500 by the pitch pin 1002 and the shaft elastic washer 1003. The pitch block 1001 is eccentric relative to the axis of the pitch cam 500 so that the pitch cam 500 rotates around the axis when the pitch block 1001 moves up and down. The pitch cam 500 has a connector 1004, and the pitch cam 500 is fixed to the blade mounting sleeve 200 by the connector 1004 in a threaded connection.
[0022] The specific steps for assembling the variable-pitch rotor blade mounting assembly for this aircraft are as follows:
[0023] 1. Press the radial needle roller bearing 700 and the axial needle roller bearing 800 onto the left and right stepped surfaces of the blade mounting sleeve 200, respectively.
[0024] 2. Insert the wear-resistant ring 900 into the inner groove of the blade mounting nut 1000, and then place the blade mounting nut 1000 along the left step surface of the blade mounting sleeve 200 to press against the left ring of the needle roller axial bearing 800.
[0025] 3. After passing the pitch pin 1002 through the corresponding mounting hole on the pitch cam 500, pass it through the mounting hole of the pitch block 1001, and use the shaft elastic washer 1003 to fix the pitch pin 1002.
[0026] 4. Install the variable pitch cam 500 onto the blade mounting sleeve 200 using three connectors 1004;
[0027] 5. Pass the blade root of blade 100 through the inner hole of blade sleeve 300, and symmetrically fit the two blade cone sleeves 400 on the corresponding inclined surface of the blade root. Then push blade 100 into the inner hole on the left side of blade mounting sleeve 200. The internal thread of the inner hole on the right side of blade sleeve 300 engages with the external thread on the left side of blade mounting sleeve 200. Fix blade 100 in blade mounting sleeve 200 according to the torque specified in the design.
[0028] 6. Tighten the four locking parts 600 to the blade pressure sleeve 300 around the circumference using threaded connections to prevent the blade 100 pressure sleeve from loosening, and the assembly is complete.
[0029] The assembled wear-resistant ring 900 and needle roller bearing transmit the bending moment at the blade root, resulting in a more balanced force distribution. This optimizes the stress on the blade root and hub, simplifies the assembly process, and improves assembly accuracy.
[0030] The specific embodiments described herein are merely illustrative examples of the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications to the described specific embodiments or adopt similar methods to replace them, but without departing from the scope defined by the spirit of this utility model.
Claims
1. An aircraft variable-pitch rotor blade mounting assembly, characterized in that, It includes a blade, a blade mounting sleeve, a blade pressure sleeve, a blade cone sleeve, and a variable pitch cam. The blade cone sleeve covers the root of the blade and is connected to the blade mounting sleeve through the blade pressure sleeve to fix the blade and the blade cone sleeve inside the blade mounting sleeve. The variable pitch cam is fixed on the tail of the blade mounting sleeve. The blade mounting sleeve has a stepped surface, and a needle roller bearing for transmitting the root bending moment and a wear ring are installed on the stepped surface.
2. The aircraft variable-pitch rotor blade mounting assembly according to claim 1, characterized in that, The needle roller bearing is divided into a radial needle roller bearing and an axial needle roller bearing. The radial needle roller bearing is installed on the right step surface of the blade mounting sleeve, and the inner ring of the radial needle roller bearing mates with the right step surface of the blade mounting sleeve. The axial needle roller bearing is installed on the left step surface of the blade mounting sleeve, and the right ring of the axial needle roller bearing mates with the left step surface of the blade mounting sleeve.
3. The aircraft variable-pitch rotor blade mounting assembly according to claim 2, characterized in that, The wear-resistant ring has a blade mounting nut, which is inserted into the inner groove of the blade mounting nut. The blade mounting nut presses against the left ring of the needle roller axial bearing along the left stepped surface of the blade mounting sleeve. The wear-resistant ring and the blade mounting sleeve slide against each other and bear their radial load.
4. An aircraft variable-pitch rotor blade mounting assembly according to claim 1, 2, or 3, characterized in that, The blade conical sleeve consists of two pieces that cover the root of the blade, with the root of the blade passing through the inner hole of the blade pressure sleeve.
5. The aircraft variable-pitch rotor blade mounting assembly according to claim 4, characterized in that, Two blade cone sleeves are symmetrically fitted onto the corresponding inclined surfaces at the root of the blade, and the blade and blade cone sleeves are fixed inside the blade mounting sleeve by the threaded connection between the blade pressure sleeve and the blade mounting sleeve.
6. An aircraft variable-pitch rotor blade mounting assembly according to claim 1, 2, or 3, characterized in that, The variable pitch cam is provided with a variable pitch block, a variable pitch pin, and a shaft elastic washer. The variable pitch block is fixed to the variable pitch cam by the variable pitch pin and the shaft elastic washer, and the variable pitch cam rotates around the axis when the variable pitch block moves up and down due to the eccentricity of the variable pitch block relative to the axis of the variable pitch cam.
7. The aircraft variable-pitch rotor blade mounting assembly according to claim 6, characterized in that, The variable pitch cam has a connecting piece, and the variable pitch cam is fixed to the blade mounting sleeve by means of a threaded connection through the connecting piece.
8. The aircraft variable-pitch rotor blade mounting assembly according to claim 1, characterized in that, The outer ring of the blade sleeve is provided with a locking element, which locks the blade sleeve in place.