Rolling friction type propeller variable-pitch crank sliding block mechanism and using method thereof

Abstract

The invention provides a rolling friction type propeller variable-pitch crank sliding block mechanism and a using method thereof. The rolling friction type propeller variable-pitch crank sliding block mechanism comprises a blade root, a variable-pitch driving unit and two eccentric bearing assemblies. A boss is arranged on the side face of the variable pitch driving unit, eccentric pins with bearings are installed on the two sides of the roots of the blades, and a clamping space is formed between the two bearings to contain the boss. When the pitch is changed, the driving unit moves axially, the boss pushes the bearing through rolling friction, and the rotation motion of the blades is converted through the eccentric pins, so that the pitch adjustment is realized. According to the structure, the boss and the double bearings are matched to replace traditional sliding block slotting, the machining process is simplified, the weight is reduced, abrasion is reduced through rolling friction, the transmission efficiency is improved, the service life is prolonged, meanwhile, assembling is easy and convenient, centering performance is good, and accurate synchronous control over the propeller pitch is facilitated. The mechanism is simple in structure, high in lightweight degree and suitable for various propeller systems.

Description

Technical Field

[0001] This invention relates to the field of aviation propeller technology, and specifically to a crank-slider mechanism for adjusting propeller pitch, particularly a rolling friction type propeller pitch-changing crank-slider mechanism. Background Technology

[0002] Existing propeller pitch control mechanisms mostly employ a structure where the pitch control drive unit has a slot on its side, and the eccentric pin of the blade is embedded in the slot. The axial movement of the slider drives the eccentric pin to slide within the slot, thereby changing the blade angle. While this type of structure is widely used, it suffers from the following problems: The slotted slider structure is complex and has high processing costs; sliding friction exists between the slot and the pin, leading to easy wear and a limited lifespan; the slotted structure increases the slider's mass, hindering lightweight design; and when controlling multiple blades synchronously, the slots require high machining precision and are difficult to assemble. Therefore, there is an urgent need for a propeller pitch-changing mechanism with a simpler structure, lighter weight, and more reliable transmission. Summary of the Invention

[0003] The purpose of this invention is to provide a rolling friction type propeller variable pitch crank slider mechanism and its usage method, which has the advantages of simple structure, light weight, high transmission efficiency and long service life.

[0004] According to one objective of the present invention, a rolling friction propeller pitch-variable crank-slider mechanism is provided, comprising a blade root and a pitch-variable drive unit, wherein a boss structure is provided on the side of the pitch-variable drive unit; a first eccentric bearing assembly and a second eccentric bearing assembly are provided on the blade root; a clamping space is formed between the first eccentric bearing assembly and the second eccentric bearing assembly, and the boss structure is embedded in the clamping space for converting the axial linear motion of the pitch-variable drive unit into the rotational motion of the blade root.

[0005] Furthermore, the boss structure is a rectangular boss.

[0006] Furthermore, both the first eccentric bearing assembly and the second eccentric bearing assembly are deep groove ball bearings.

[0007] Furthermore, the variable pitch drive unit is driven by a hydraulic cylinder, an electric lead screw, or a linear motor.

[0008] Furthermore, a first eccentric pin and a second eccentric pin are provided at the root of the blade, the first eccentric bearing assembly is installed on the first eccentric pin, and the second eccentric bearing assembly is installed on the second eccentric pin.

[0009] Furthermore, the thickness of the boss structure is less than the width of the clamping space, allowing the boss structure to slide smoothly and without gaps between the first eccentric bearing assembly and the second eccentric bearing assembly.

[0010] Furthermore, the working surface of the boss structure forms a line contact with the outer ring of the bearing.

[0011] Furthermore, the root of the blade is a cylindrical structure with threaded holes on its outer circumferential side, through which the first eccentric pin and the second eccentric pin are installed.

[0012] The method of using the above-mentioned rolling friction propeller pitch-changing crank-slider mechanism includes the following steps: The variable pitch drive unit moves axially. The boss structure moves accordingly, driving the first eccentric bearing assembly and the second eccentric bearing assembly to move; The eccentric action of the eccentric pin converts linear motion into rotational motion around the blade root's axis, thus achieving pitch adjustment.

[0013] Furthermore, the mechanism is applicable to propeller systems of fixed-wing aircraft, helicopters, or drones.

[0014] This invention employs a rolling friction fit structure with a double eccentric bearing and a boss, replacing the traditional sliding friction form of a slotted slider and eccentric pin, resulting in several significant advantages. This structure greatly simplifies the design of the variable pitch drive unit, eliminating the complex and costly axial groove, reducing manufacturing difficulty and cost, and achieving lightweight components, thus contributing to improved overall aircraft performance. Utilizing the rolling friction between the bearing and the boss effectively overcomes the wear problem associated with traditional sliding friction, resulting in higher transmission efficiency, smoother and more reliable mechanism operation, and a significantly extended service life. The double bearing assembly naturally clamps and guides the boss, simplifying assembly and ensuring good centering, which facilitates precise and synchronous control of the propeller pitch, improving the overall rigidity and adjustment accuracy of the system. In summary, this mechanism achieves substantial progress in structural simplification, weight reduction and efficiency improvement, wear resistance and long service life, and assembly control accuracy, possessing outstanding practical value and promising prospects for widespread application. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 This is an exploded view of the structure according to an embodiment of the present invention; Figure 3 This is a partially enlarged view of the cooperation between the variable pitch drive unit and the eccentric bearing at the blade root in an embodiment of the present invention; Figure 4 This is a schematic diagram of a traditional slotted structure according to an embodiment of the present invention.

[0017] In the figure: 1. Blade root; 2. First eccentric bearing assembly; 3. Pitch drive unit; 301. Boss structure; 4. Second eccentric bearing assembly; 5. First eccentric pin; 6. Second eccentric pin. Detailed Implementation

[0018] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example 1 like Figures 1-3 As shown, a rolling friction propeller pitch-variable crank-slider mechanism includes a blade root 1, a first eccentric bearing assembly 2, a pitch-variable drive unit 3, and a second eccentric bearing assembly 4, wherein: The variable pitch drive unit 3 has a boss structure 301 on its side, and the root of the blade root 1 has two eccentric pins. Specifically, the blade root 1 is a cylindrical structure with two threaded holes on its outer circumferential side. Eccentric pins are installed in the threaded holes to fix the bearing assembly.

[0022] The eccentric pins include a first eccentric pin 5 and a second eccentric pin 6, which are symmetrically arranged on both sides of the blade root. A first eccentric bearing assembly 2 and a second eccentric bearing assembly 4 are respectively mounted on the two eccentric pins, forming a clamping space between the two bearing assemblies. A boss structure 301 is embedded in this clamping space, realizing the conversion between the linear motion of the slider and the rotational motion of the blade.

[0023] In this embodiment, the boss is rectangular and slides in close contact with the bearing. The bearing assembly is a deep groove ball bearing, which has good load-bearing and self-lubricating properties and can withstand radial forces during pitch changes.

[0024] The mechanism described in this embodiment is applicable to propeller systems of fixed-wing aircraft, helicopters, or drones.

[0025] The first eccentric bearing assembly 2 and the second eccentric bearing assembly 4 are completely identical, and are combined vertically to clamp the boss structure of the pitch-changing drive unit 3.

[0026] The variable pitch drive unit 3 can be driven to move up and down axially via a hydraulic cylinder, electric lead screw, or linear motor. Driving the variable pitch drive unit 3 to move up and down axially causes the eccentric bearing assembly to move up and down. The eccentric bearing assembly, through its cooperation with the boss of the variable pitch drive unit, converts the linear motion of the slider into the rotational motion of the blade, thereby realizing the pitch adjustment.

[0027] like Figure 3 The image shown is a partially enlarged view of the connection between the pitch drive unit and the blade root. The first eccentric pin 5 and the second eccentric pin 6 are arranged parallel to each other on both sides of the blade root 1, with their axes parallel to the blade axis. A clamping space is formed between the first eccentric bearing assembly 2 and the second eccentric bearing assembly 4, and the boss structure of the pitch drive unit 3 is embedded in this clamping space.

[0028] The thickness of the boss structure of the variable pitch drive unit 3 is slightly smaller than the width of the clamping space, so that the boss structure 301 can slide smoothly between the first eccentric bearing assembly 2 and the second eccentric bearing assembly 4, and ensure that there is no gap between the bearing and the boss, thus ensuring precise control of the blade angle.

[0029] In actual operation, the up-and-down movement of the boss structure 301 of the pitch drive unit 3 drives the eccentric bearing assembly to move up and down, thereby determining the rotational motion of the blade along the blade axis. When the pitch drive unit 3 moves up or down, the boss structure generates relative motion with the first eccentric bearing assembly 2 and the second eccentric bearing assembly 4. Since the first eccentric bearing assembly 2 and the second eccentric bearing assembly 4 are connected to the blade root 1 through the first eccentric pin 5 and the second eccentric pin 6 respectively, this relative motion is converted into the rotational motion of the blade around its own axis, thereby achieving precise adjustment of the blade pitch.

[0030] In a preferred embodiment, the boss may have a rectangular cross-section, and its working surface forms line contact with the outer ring of the bearing, thus having a high load-bearing capacity.

[0031] The first eccentric bearing assembly 2 and the second eccentric bearing assembly 4 are preferably deep groove ball bearings, which are characterized by compact structure and low coefficient of friction. In high-speed applications, angular contact bearings can be selected to improve axial load capacity based on the variable pitch characteristics; in low-speed, heavy-load applications, sliding bearings can be selected to reduce costs.

[0032] The variable pitch drive unit 3 can be selected from different drive forms according to specific application requirements. In applications supporting aero-engines, hydraulic cylinder drive is preferred due to its high power density and fast response speed. In applications of electric aircraft such as UAVs, electric lead screws or linear motors can be used, offering advantages such as high control precision and good system integration.

[0033] like Figure 4 The diagram shows a comparison between a traditional slotted structure and the structure of this invention. In the traditional structure, the variable pitch drive unit requires machining complex axial slots, blade eccentric pins, and bearings that slide within the slots. In contrast, this invention eliminates the complex slotted structure, employing a simple boss and double bearing assembly, which not only simplifies the manufacturing process but also significantly reduces the weight of the parts.

[0034] During assembly, two eccentric pins with bearings are first installed at the blade root, and then the boss of the variable pitch drive unit is embedded into the clamping space formed between the two bearings. This assembly method is simple and reliable, ensuring assembly accuracy without the need for special tooling. Furthermore, the use of standardized bearing parts makes maintenance and replacement very convenient.

[0035] This mechanism is applicable to various propeller systems, and is particularly suitable for applications requiring synchronous pitch control of multiple blades. By strategically arranging the mounting positions at the roots of multiple blades, precise synchronous control of all blades can be achieved, ensuring flight stability.

[0036] Furthermore, the present invention can be modified to meet different application requirements. For example, the height and width of the boss can be adjusted to accommodate different pitch ranges; different load requirements can be met by selecting bearings of different sizes; and the pitch transmission ratio can be adjusted by changing the eccentricity of the eccentric pin.

[0037] In summary, this invention, through its innovative boss and double bearing clamping structure, simplifies, lightens, and increases the efficiency of the propeller pitch mechanism, demonstrating significant technological advancement and practical value.

[0038] The invention significantly reduces weight. By removing the slot structure, the mass of the variable pitch drive unit is reduced, and the overall weight of the mechanism is lowered, which is beneficial to improving the performance of the aircraft.

[0039] This invention features high transmission efficiency, low wear, and unilateral rolling friction between the bearing and the boss, overcoming the shortcomings of double-sided friction in slotted structures with single bearings, resulting in a long service life.

[0040] This invention is easy to assemble and has high precision. The double bearing clamping structure has good centering and is simple to assemble, which is beneficial for precise control of the pitch angle.

[0041] This invention has strong applicability and can be widely applied to various propeller systems such as fixed-wing aircraft, helicopters, and drones.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rolling friction type propeller variable pitch crank-slider mechanism, characterized in that, The device includes a blade root and a pitch drive unit. The pitch drive unit has a boss structure on its side. The blade root is provided with a first eccentric bearing assembly and a second eccentric bearing assembly. A clamping space is formed between the first eccentric bearing assembly and the second eccentric bearing assembly. The boss structure is embedded in the clamping space to convert the axial linear motion of the pitch drive unit into the rotational motion of the blade root.

2. The rolling friction type propeller variable pitch crank-slider mechanism according to claim 1, characterized in that, The boss structure is a rectangular boss.

3. The rolling friction type propeller variable pitch crank-slider mechanism according to claim 1, characterized in that, Both the first eccentric bearing assembly and the second eccentric bearing assembly are deep groove ball bearings.

4. The rolling friction type propeller variable pitch crank-slider mechanism according to claim 1, characterized in that, The variable pitch drive unit is driven by a hydraulic cylinder, an electric lead screw, or a linear motor.

5. The rolling friction type propeller variable pitch crank-slider mechanism according to claim 1, characterized in that, The blade root is provided with a first eccentric pin and a second eccentric pin, the first eccentric bearing assembly is installed on the first eccentric pin, and the second eccentric bearing assembly is installed on the second eccentric pin.

6. The rolling friction type propeller variable pitch crank-slider mechanism according to claim 1, characterized in that, The thickness of the boss structure is less than the width of the clamping space, so that the boss structure can slide smoothly and without gaps between the first eccentric bearing assembly and the second eccentric bearing assembly.

7. The rolling friction type propeller variable pitch crank-slider mechanism according to claim 1, characterized in that, The working surface of the boss structure forms a line contact with the outer ring of the bearing.

8. The rolling friction type propeller variable pitch crank-slider mechanism according to claim 5, characterized in that, The blade root is a cylindrical structure with threaded holes on the outer circumferential side, through which the first eccentric pin and the second eccentric pin are installed.

9. The method of using the rolling friction propeller variable pitch crank-slider mechanism according to any one of claims 1-8, characterized in that, Includes the following steps: The variable pitch drive unit moves axially. The boss structure moves accordingly, driving the first eccentric bearing assembly and the second eccentric bearing assembly to move; The eccentric action of the eccentric pin converts linear motion into rotational motion around the blade root's axis, thus achieving pitch adjustment.

10. The rolling friction type propeller variable pitch crank-slider mechanism according to claim 1, characterized in that, The mechanism is applicable to propeller systems of fixed-wing aircraft, helicopters, or unmanned aerial vehicles.

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