A detachable composite material rotor

Abstract

This utility model discloses a detachable composite material rotor, including a metal hub and several blade assemblies. The diameter of the metal hub decreases from one end to the other. A dovetail groove spirals from the larger end to the smaller end of the metal hub and does not penetrate through the smaller end. A wedge-shaped fastening groove spirals from the larger end to the smaller end on the bottom surface of the dovetail groove. The blade assembly includes a transition metal part and composite material blades. The transition metal part includes a curved body in the middle, a wedge-shaped dovetail inside the curved body, and a metal blade outside the curved body. The shape of the curved body is adapted to the dovetail groove and is assembled within it. The shape of the wedge-shaped dovetail is adapted to the wedge-shaped fastening groove and is assembled within it. The composite material blades cover the outer surface of the transition metal part and are integrally formed with it to form the blade assembly. In this utility model, both the hub and the blade assembly fastening surfaces are metal, reducing the rotational friction effect. Moreover, locking and disassembly functions can be achieved through physical assembly only.

Description

Technical Field

[0001] This utility model relates to the field of rotor technology, and in particular to a detachable composite material rotor. Background Technology

[0002] Traditional blade assemblies are mainly made of metal materials, while blade assemblies made of carbon fiber reinforced composite materials have the advantages of low vibration, low noise, light weight and high efficiency, seawater corrosion resistance and easy maintenance compared with traditional metal propellers. Composite material rotors have great application potential in both military and civilian fields.

[0003] Rotors can be divided into two categories: integral and split. Integral rotors are currently further divided into metal and non-metal (composite materials) types based on raw materials. Metal rotors are made by casting metal and then machining it to obtain the final shape. However, the manufacturing process of composite integral rotors is more complex and difficult, and there are still some obstacles in manufacturing: First, considering the molding characteristics and requirements of composite materials, the design of integral rotor molds and tooling is complex and the size is larger, resulting in higher manufacturing difficulty and cost. Second, the molding process of composite materials is complex, generally divided into processes such as laying, curing, and demolding. Liquid molding also includes a glue injection process. There are many molding process parameters, and the control is difficult. After molding, it cannot be machined like metal. Once a quality problem occurs, it must be scrapped, resulting in high costs. Third, if one blade of an integral rotor is damaged, the entire rotor cannot continue to be used. The cost of composite integral rotors is relatively higher than that of metal rotors, and the replacement cost is also higher.

[0004] A split-type rotor connects multiple separate blades to a metal hub. The load acting on the blades is transferred to the metal hub through the blade root connection. Therefore, the blade root connection method plays a decisive role in the safe operation of the rotor. Most existing connection technologies use a single composite blade root directly fastened to the metal hub with tenon and mortise joints, or a metal part embedded in the blade root with an upward-protruding boss. The first connection method is simple to operate, but because the fastening surfaces are the metal hub and the composite blade root, and the two are processed differently, there are deviations in precision after forming. This results in a large error in assembly. At the same time, considering the difference in stiffness between the metal hub and the composite blades, the friction effect is significant during rotor rotation, inevitably leading to gradual loosening. The disassembly process will also exacerbate the loosening, eventually leading to fastening failure. While the second connection method can solve the friction effect, with the updating of rotor fluid design, the diameter of the hub has evolved from a constant diameter to a gradually changing diameter (frustum-shaped), and the twist angle at the blade root is also larger. These designs can effectively improve some hydrodynamic performance, but they also result in a hub diameter ratio greater than 1.5. The pitch angle when the helix is ​​mapped onto the hub surface has deviated significantly from the theoretical pitch angle. At this point, the helical dovetail grooves cut on the frustum-shaped hub surface alone cannot provide a fastening effect. Utility Model Content

[0005] The main purpose of this utility model is to provide a detachable composite material rotor. The composite material blade assembly is formed in pieces, which is simple and feasible to process. After forming, the blade is screwed in from the large end and then locked with metal end cap screws. All assembly surfaces are metal, which ensures high assembly positioning accuracy and convenient and firm installation. The blades do not loosen, fall out or get damaged during operation.

[0006] The technical solution adopted in this utility model is:

[0007] A detachable composite material rotor includes a metal hub and a plurality of blade assemblies detachably mounted circumferentially along the metal hub. The metal hub has dovetail grooves circumferentially formed in a number consistent with the number of blade assemblies. The diameter of the metal hub decreases from one end to the other. The dovetail grooves spiral from the larger end to the smaller end of the metal hub and do not penetrate through the smaller end. A wedge-shaped fastening groove spirally formed on the bottom surface of each dovetail groove from the larger end to the smaller end. Each blade assembly includes a transition metal component and composite material blades. The transition metal component includes a blade located in the middle... The rotor comprises a curved body, a wedge-shaped dovetail located inside the curved body, and metal blades located outside the curved body; the shape of the curved body is adapted to the dovetail groove and assembled within the dovetail groove, and the shape of the wedge-shaped dovetail is adapted to the wedge-shaped fastening groove and assembled within the wedge-shaped fastening groove; the composite material blades cover the outer surface of the transition metal part and are integrally formed therewith to form the blade assembly; the detachable composite material rotor also includes a metal end cap, which is located at the large end of the metal hub and is fixedly connected to both the metal hub and the transition metal part.

[0008] In the above scheme, the width of the dovetail groove decreases from the large end to the small end, and the width of the dovetail groove at any cross-section is in the range of 1.2d / n to 2.5d / n, where n is the number of rotor blades and d is the diameter of the rotor hub at that cross-section.

[0009] In the above scheme, the width of the wedge-shaped fastening groove decreases from the large end to the small end, and the deceleration rate of the width of the wedge-shaped fastening groove is consistent with the deceleration rate of the width of the dovetail groove.

[0010] In the above scheme, the depth of the dovetail groove decreases from the large end to the small end to ensure that the diameter of the bottom surface of the dovetail groove is equal from the large end to the small end; the depth range of the dovetail groove is 0.015D to 0.02D, where D is the diameter of the detachable composite material rotor.

[0011] In the above scheme, the depth of the wedge-shaped fastening groove remains consistent from the large end to the small end.

[0012] In the above scheme, the angle between the two inclined surfaces of the dovetail groove and the bottom surface is between 70° and 85°; the angle between the two inclined surfaces of the wedge-shaped fastening groove and the bottom surface is consistent with the angle between the two inclined surfaces of the dovetail groove and the bottom surface.

[0013] In the above scheme, the length of the wedge-shaped fastening groove along the axial direction of the metal hub is 1 / 2 to 2 / 3 of the length of the dovetail groove.

[0014] In the above scheme, the intersection of the two opposite inclined surfaces of the dovetail groove with the bottom surface is machined into rounded corners; the intersection of the two opposite inclined surfaces of the curved body of the transition metal part with the bottom surface is machined into rounded corners with matching dimensions.

[0015] In the above scheme, the intersection of the two opposite inclined surfaces of the wedge-shaped fastening groove with the bottom surface is processed into rounded corners; the intersection of the two opposite inclined surfaces of the wedge-shaped dovetail of the transition metal part with the bottom surface is processed into a gradient rounded corner, and the minimum value of the gradient rounded corner radius range is greater than the rounded corner radius of the wedge-shaped fastening groove, and the maximum value of the gradient rounded corner radius range is less than 5mm.

[0016] In the above scheme, the diameter ratio of the large end to the small end of the metal propeller hub is greater than 1.5.

[0017] The beneficial effects of this utility model are:

[0018] This utility model proposes a detachable composite material rotor. The dovetail groove and wedge-shaped fastening groove on the metal hub are respectively assembled with the curved surface and wedge-shaped dovetail of the transition metal part. All assembly and fastening surfaces are metal, ensuring consistency in the stiffness of the hub and blades and reducing friction. Furthermore, the locking function is achieved through physical assembly only. Specifically, due to the gradual change in depth of the dovetail groove, the helix of the wedge-shaped fastening groove is actually opened on the surface of the hub with a constant diameter. Simultaneously, the pitch angle of the helix is ​​consistent with the pitch angle at the root of the rotor blade. Due to the coincidence of the helix direction and the design of the dovetail cross-section, the circumferential and radial connection and locking of the rotor blade root are ensured. At the same time, the end cover is connected to the hub and transition metal part with screws to ensure axial locking. Disassembly only requires unscrewing the screws, removing the end cover, and then unscrewing the rotor blade in the opposite direction along the rotation path. Therefore, assembly and disassembly operations are simple. Moreover, all assembly surfaces are machined from metal, ensuring controllable and consistent forming precision, guaranteeing high assembly and positioning accuracy of the final product.

[0019] The transition metal part of the composite blade assembly is inserted from the large end of the rotor hub. The transition metal part, rotor hub, and end cap are then fixed together to apply a tightening force, ensuring the blade is properly installed. This method is convenient and does not damage the composite blade. The end cap and rotor hub are fixed together, and after testing in operation, no blade loosening, detachment, or damage occurred, demonstrating high connection reliability. The design of the dovetail groove and wedge-shaped fastening groove on the rotor hub fully considers the blade's fluid profile, structure, performance, and manufacturing characteristics, making it suitable for various submersible rotors, especially those with a frustum-shaped rotor hub. It also enables the detachability of individual rotor blades. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the detachable composite material rotor in an embodiment of this utility model;

[0022] Figure 2 yes Figure 1 A cross-sectional view of the detachable composite rotor shown.

[0023] Figure 3 yes Figure 1 A schematic diagram of the metal hub of the detachable composite rotor is shown.

[0024] Figure 4 yes Figure 3 The front view;

[0025] Figure 5 yes Figure 1 A schematic diagram of the transition metal component of the detachable composite material rotor is shown.

[0026] Figure 6 yes Figure 1 A schematic diagram of the composite material blades of the detachable composite material rotor is shown.

[0027] Figure 7 yes Figure 1 The diagram shows the structure of the metal end cap of the detachable composite material rotor.

[0028] In the diagram: 10. Metal propeller hub; 11. Dovetail groove; 12. Wedge-shaped fastening groove;

[0029] 20. Blade assembly; 21. Transition metal part; 211. Curved surface; 212. Wedge-shaped dovetail; 213. Metal blade; 22. Composite material blade;

[0030] 30. Metal end cap; 31. First screw hole; 32. Second screw hole. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0032] It should be noted that the illustrations provided in the embodiments of this utility model are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show the components related to this utility model and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0033] In this utility model, it should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," 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 application 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 limitations on this application. Furthermore, the terms "first" and "second" are used only for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0034] like Figure 1 As shown, this embodiment proposes a detachable composite material rotor, including a metal hub 10 and a seven-blade assembly 20 detachably mounted circumferentially along the metal hub 10, as well as a metal end cap 30. The diameter D of the detachable composite material rotor is 1200 mm.

[0035] like Figure 3-4 As shown, seven dovetail grooves 11 are circumferentially formed on the metal rotor hub 10 for mounting seven blade assemblies 20. The diameter of the metal rotor hub 10 decreases from one end to the other. The dovetail grooves 11 spiral from the larger end of the metal rotor hub 10 to the smaller end and do not penetrate through the smaller end. The axial length of the dovetail grooves 11 on the metal rotor hub 10 cannot penetrate the entire metal rotor hub 10; the reserved portion serves as the axial assembly reference between the blade and the metal rotor hub 10, and the axial length of the reserved portion can be defined by the user. The bottom surface of the dovetail grooves 11 spirals from the larger end to the smaller end and has wedge-shaped fastening grooves 12.

[0036] like Figure 2 As shown, the blade assembly 20 includes a transition metal part 21 and a composite material blade 22. (As indicated...) Figure 5 As shown, the transition metal part 21 includes a curved body 211 located in the middle, a wedge-shaped dovetail 212 located inside the curved body 211, and a metal blade 213 located outside the curved body 211. The shape of the curved body 211 is adapted to the dovetail groove 11 and is assembled within the dovetail groove 11. The shape of the wedge-shaped dovetail 212 is adapted to the wedge-shaped fastening groove 12 and is assembled within the wedge-shaped fastening groove 12, and the assembly paths of the curved body 211 and the wedge-shaped dovetail 212 do not interfere with each other. Composite material blade 22, as... Figure 6 As shown, it covers the outer surface of the transition metal part 21 and is integrally formed with it to form the blade assembly 20. Specifically, after the composite material blade 22 is laid with fibers of equal thickness on the lower blade mold, the transition metal part 21 is added. The transition metal part 21 is precisely positioned by the mold positioning fixture. Then, the upper blade mold fiber cloth layer is laid on the surface of the transition metal part 21. Finally, the overall molding is completed by the autoclave process.

[0037] like Figure 7 As shown, the metal end cap 30 is located at the large end of the metal propeller hub 10 and is fixedly connected to both the metal propeller hub 10 and the transition metal part 21.

[0038] During assembly, align the curved surface 211 and wedge-shaped dovetail 212 of the blade assembly 20 with the dovetail groove 11 and wedge-shaped fastening groove 12 of the metal rotor hub 10, respectively, and screw them in from the large end to the small end. Finally, mechanically fix the metal end cap 30 to the metal rotor hub 10 and the transition metal part 21. During disassembly, first remove the metal end cap 30, and then gently tap the guide edge of the blade assembly 20 in the opposite direction (from the small end to the large end) with a rubber mallet. Individual blade assemblies 20 can then be disassembled one by one.

[0039] Further optimization involves screwing the blade assembly 20 from the large end to the small end of the metal hub 10. Then, it is first assembled with the transition metal part 21 using screws through seven evenly distributed first screw holes 31 on the metal end cap 30. Under the tightening force provided by the screws, the gap between the mating surfaces of the metal end cap 30 and the transition metal part 21 gradually decreases, and the blade assembly 20 moves towards the termination end face in the dovetail groove 11. Tightening the screws reduces the gap between the metal end cap 30 and the hub mating surface to less than 0.1 mm, at which point the blade assembly 20 is in place. Finally, it is fastened to the large end of the hub using screws through seven evenly distributed second screw holes 32 on the metal end cap 30, resulting in the final rotor product.

[0040] The assembly is completed by applying a tightening force to make the gap between the metal end cap 30 and the metal rotor hub 10 contact plane less than 0.1mm. After the assembly is completed, a gap is allowed between the end face of the dovetail groove 11 and the small end face of the blade root.

[0041] Further optimization is needed. The shape and size design of the dovetail groove 11 on the metal rotor hub 10 should consider the root pitch angle trend of the composite blade 22 and the limitations of the material and size of the metal rotor hub 10. Simultaneously, the load-bearing capacity and rigidity requirements of the composite blade 22, as well as the limitations of the forming thickness and the processing difficulty of the transition metal part 21, must be considered. It should not be too thin or too thick. The depth of the dovetail groove 11 is in the range of 0.015D to 0.02D, where D is the diameter of the detachable composite rotor. The width of the dovetail groove 11 varies with the diameter at both ends of the metal rotor hub 10, decreasing from the larger end to the smaller end. The width of the dovetail groove 11 at any cross-section is in the range of 1.2d / n to 2.5d / n, where n is the number of rotor blades and d is the rotor hub diameter at that cross-section. The angle α between the two inclined surfaces of the dovetail groove 11 and the bottom surface is between 70° and 85°. Based on the design consideration that the wedge-shaped fastening groove 12 is preferably opened on a rotor hub of equal diameter, as the width of the dovetail groove 11 decreases, the depth of the dovetail groove 11 also decreases to ensure that the diameter of the bottom surface of the dovetail groove 11 is equal from the large end to the small end. For machining considerations, the intersection of the two opposite inclined surfaces of the dovetail groove 11 with the bottom surface is machined into rounded corners, and the intersection of the two opposite inclined surfaces of the curved surface 211 of the transition metal part 21 with the bottom surface is machined into rounded corners with matching dimensions.

[0042] Further optimization is needed. The shape and size of the wedge-shaped fastening groove 12 must not only be consistent with the helix of the dovetail groove 11 to ensure a consistent movement path during insertion and avoid interference, but also ensure its locking function. The wedge-shaped fastening groove 12 is located in the middle of the dovetail groove 11, and its length along the axial direction of the metal hub 10 is 1 / 2 to 2 / 3 of the length of the dovetail groove 11. The width of the wedge-shaped fastening groove 12 also decreases from the larger end to the smaller end, and the rate of decrease is consistent with the rate of decrease of the width of the dovetail groove 11 to avoid path interference. The depth of the wedge-shaped fastening groove 12 remains consistent from the larger end to the smaller end to ensure the rigidity and reliability of the connection. At the same time, the angle β between the two inclined surfaces and the bottom surface of the wedge-shaped fastening groove 12 is consistent with the angle α between the dovetail groove 11, so as to ensure that the movement trend of the transition metal part 21 is consistent with the two slots on the hub when it is screwed in from the larger end to the smaller end. For machining considerations, the intersection of the two opposite inclined surfaces of the wedge-shaped fastening groove 12 with the bottom surface is machined into rounded corners. The intersection of the two opposite inclined surfaces of the wedge-shaped dovetail 212 of the transition metal part 21 with the bottom surface is machined into a gradient rounded corner. For assembly considerations, the minimum value of the gradient rounded corner radius range must be greater than the rounded corner radius of the wedge-shaped fastening groove 12; for locking considerations, the maximum value of the gradient rounded corner radius range must be less than 5mm. Based on all the above conditions, interference in the movement paths of the curved body 211 and the wedge-shaped dovetail 212 can be avoided to the greatest extent; at the same time, it has a locking function. Specifically, the helix of the wedge-shaped fastening groove 12 is mapped onto the surface of the same diameter propeller hub, and its pitch angle parameter is consistent with the blade root pitch angle of the blade assembly 20. The angle β between its inclined surface and the bottom surface is designed to be an acute angle. When the blade assembly 20 is screwed in, the rotation directions coincide, realizing axial and radial physical locking. The screw fastening of the metal end cap 30 ensures the axial locking of the entire assembly.

[0043] Further optimization involves the metal hub 10 being truncated cone-shaped, with a diameter ratio between its large and small ends greater than 1.5. In this embodiment, the large end diameter is 330 mm, and the small end diameter is 161 mm.

[0044] Further optimizations include the use of titanium alloy for the metal hub 10 and transition metal parts 21, and the use of carbon fiber reinforced epoxy resin matrix composite for the composite blades 22.

[0045] Using this invention, the blade assembly 20 is installed onto the metal hub 10, and the metal end cap 30 is fastened to the metal hub 10 with screws. The resulting seven-bladed rotor is tested under the designed operating conditions. The blades are not damaged or detached, and the pitch, lateral tilt, and longitudinal tilt of the blades do not change, proving the feasibility of this invention.

[0046] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this utility model.

[0047] The order of the steps in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0048] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A detachable composite material rotor, comprising a metal hub and a plurality of blade assemblies detachably mounted along the circumference of the metal hub; characterized in that, The metal rotor hub has dovetail grooves circumferentially arranged in a number consistent with the number of blade assemblies. The diameter of the metal rotor hub decreases from one end to the other. The dovetail grooves spiral from the large end to the small end of the metal rotor hub and do not penetrate through the small end. The bottom surface of the dovetail grooves spirally forms wedge-shaped fastening grooves from the large end to the small end. The blade assembly includes a transition metal part and a composite material blade. The transition metal part includes a curved body located in the middle, a wedge-shaped dovetail located inside the curved body, and a metal blade located outside the curved body. The shape of the curved body is adapted to the dovetail groove and is assembled in the dovetail groove. The shape of the wedge-shaped dovetail is adapted to the wedge-shaped fastening groove and is assembled in the wedge-shaped fastening groove. The composite material blades cover the outer surface of the transition metal part and are integrally formed with it to form the blade assembly. The detachable composite material rotor also includes a metal end cap, which is located at the large end of the metal rotor hub and is fixedly connected to both the metal rotor hub and the transition metal part.

2. The detachable composite material rotor according to claim 1, characterized in that, The width of the dovetail groove decreases from the larger end to the smaller end, and the width of the dovetail groove at any cross-section is in the range of 1.2d / n to 2.5d / n, where n is the number of rotor blades and d is the diameter of the rotor hub at that cross-section.

3. The detachable composite material rotor according to claim 2, characterized in that, The width of the wedge-shaped fastening groove decreases from the larger end to the smaller end, and the rate of decrease in the width of the wedge-shaped fastening groove is consistent with the rate of decrease in the width of the dovetail groove.

4. The detachable composite material rotor according to claim 1, characterized in that, The depth of the dovetail groove decreases from the large end to the small end to ensure that the diameter of the bottom surface of the dovetail groove is equal from the large end to the small end; the depth range of the dovetail groove is 0.015D to 0.02D, where D is the diameter of the detachable composite material rotor.

5. The detachable composite material rotor according to claim 4, characterized in that, The depth of the wedge-shaped fastening groove remains consistent from the larger end to the smaller end.

6. The detachable composite material rotor according to claim 1, characterized in that, The angle between the two inclined surfaces of the dovetail groove and the bottom surface is between 70° and 85°; the angle between the two inclined surfaces of the wedge-shaped fastening groove and the bottom surface is consistent with the angle between the two inclined surfaces of the dovetail groove and the bottom surface.

7. The detachable composite material rotor according to claim 1, characterized in that, The length of the wedge-shaped fastening groove along the axial direction of the metal hub is 1 / 2 to 2 / 3 of the length of the dovetail groove.

8. The detachable composite material rotor according to claim 1, characterized in that, The intersection of the two opposite inclined surfaces of the dovetail groove with the bottom surface is machined into rounded corners; the intersection of the two opposite inclined surfaces of the curved body of the transition metal part with the bottom surface is machined into rounded corners of matching size.

9. The detachable composite material rotor according to claim 1, characterized in that, The intersection of the two opposite inclined surfaces of the wedge-shaped fastening groove with the bottom surface is machined into a rounded corner; the intersection of the two opposite inclined surfaces of the wedge-shaped dovetail of the transition metal part with the bottom surface is machined into a gradient rounded corner, and the minimum value of the gradient rounded corner radius range is greater than the rounded corner radius of the wedge-shaped fastening groove, and the maximum value of the gradient rounded corner radius range is less than 5mm.

10. The detachable composite material rotor according to claim 1, characterized in that, The ratio of the diameter of the large end to the small end of the metal propeller hub is greater than 1.5.

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