Connecting structure of propeller blade and propeller hub

Abstract

The utility model discloses a connecting structure of a propeller blade and a propeller hub, and relates to the technical field of connecting structures, a radial thrust ball bearing is installed between the outer wall of a propeller root and the inner wall of the propeller hub, a tapered roller bearing is installed on the periphery of the propeller blade and is arranged close to a cuff of the propeller hub, and a limiting retaining assembly is located between the propeller hub and the propeller blade. The limiting maintaining assembly is located between the radial thrust ball bearing and the tapered roller bearing, a pressing oil cavity is formed between the limiting maintaining assembly and the inner wall of the propeller hub, and the pre-tightening element can be detachably installed on an outer ring of the tapered roller bearing; after the centripetal thrust ball bearing is installed, high-pressure oil is introduced into the pressing oil cavity so that the tapered roller bearing outer ring can tend to move in the direction away from the propeller root, due to the fact that the tapered roller bearing has a taper angle, the tapered roller bearing outer ring expands in the radial direction, at the moment, the pre-tightening element is tightened and fixed, and gaps between the propeller blades and the propeller hub can be eliminated. According to the utility model, accurate positioning and reliable connection of the propeller blades and the propeller hub can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of connection structures, in particular to a connection structure between a propeller blade and a hub. Background Art

[0002] Composite blades and aluminum alloy hubs have become important symbols of advanced propellers. The connection structure between the blades and the hub is a prerequisite for achieving reliable connection between the blades and the hub, realizing the interchange of blades in the field, and ensuring the environmental adaptability of the propeller.

[0003] When the propeller is working, no radial gap is allowed between the blade and the hub. The existence of the gap will increase the vibration of the blade, and the force exerted by the blade on the hub will also add an impact load, which is not good for fatigue performance. However, in order to facilitate assembly, a certain gap will inevitably exist. Therefore, a connection structure between the blade and the hub is designed to ensure accurate positioning and reliable connection. Utility Model Content

[0004] The utility model aims to provide a connection structure between a propeller blade and a hub, so as to realize accurate positioning and reliable connection between the propeller blade and the hub.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] The utility model provides a connection structure between a propeller blade and a hub, comprising a centripetal thrust ball bearing, a tapered roller bearing, a limit retaining assembly and a pre-tightening element, wherein the centripetal thrust ball bearing is installed between the outer wall of the blade root and the inner wall of the hub, the tapered roller bearing is installed on the outer periphery of the blade and is arranged close to the cuff of the hub, the limit retaining assembly is located between the hub and the blade, and the limit retaining assembly is located between the centripetal thrust ball bearing and the tapered roller bearing, a pressure oil chamber is formed between the limit retaining assembly and the inner wall of the hub, and the pre-tightening element can be detachably installed on the outer ring of the tapered roller bearing; after the centripetal thrust ball bearing is installed, high-pressure oil is introduced into the pressure oil chamber to give the outer ring of the tapered roller bearing a movement tendency away from the blade root direction, and due to the tapered roller bearing having a cone angle, the outer ring of the tapered roller bearing expands radially, and at this time, tightening the pre-tightening element to fix it can eliminate the gap between the blade and the hub.

[0007] Preferably, the radial thrust ball bearing and the tapered roller bearing are both split bearings.

[0008] Preferably, the limit retaining assembly includes a retaining frame, a support frame and a sealing ring, the retaining frame and the support frame are both sleeved on the outer circumference of the blade, and one end of the retaining frame contacts one side of the centripetal thrust ball bearing, the other end of the retaining frame abuts one side of the support frame, and the other side of the support frame abuts one side of the tapered roller bearing, and the pressure oil chamber is formed between the outer wall of the support frame and the hub, the sealing ring is installed on the outer wall of the support frame, and a sealing ring is provided on each side of the pressure oil chamber.

[0009] Preferably, the support frame includes a first support section and a second support section, the outer diameter of the first support section is smaller than the outer diameter of the second support section, and one end of the first support section abuts one end of the retaining frame, the other end of the first support section is integrally formed with one end of the second support section, and the other end of the second support section abuts one end of the tapered roller bearing; the inner wall of the hub is provided with an annular protrusion at a position corresponding to the retaining frame, one end of the annular protrusion can extend to the outer wall of a partial section covering the first support section, one side of the annular protrusion, the inner wall of the hub, the first support section and one side of the second support section form the pressurized oil chamber; the sealing ring is provided between the outer wall of the first support section and the inner wall of the annular protrusion, and between the outer wall of the second support section and the inner wall of the hub.

[0010] Preferably, the outer ring of the tapered roller bearing and the support frame are press-fitted together by interference fit.

[0011] Preferably, a bearing washer is provided between the outer ring of the centripetal thrust ball bearing and the inner wall of the hub, and the bearing washer is made of non-metallic material.

[0012] Preferably, it also includes a bushing, a lightning conductor and an anti-wear pad, the bushing and the lightning conductor are both sleeved on the outer circumference of the tapered roller bearing and located between the tapered roller bearing and the hub, the lightning conductor is located on the side of the bushing away from the root of the blade, the anti-wear pad is located between the preloaded element and the end face of the hub, and the bushing and the anti-wear pad are both made of non-metallic materials.

[0013] Preferably, the pre-tightening element includes a pre-tightening nut and an anti-loosening element, the pre-tightening nut is connected to the outer ring of the tapered roller bearing through a thread, and the anti-loosening element is installed on the pre-tightening nut and the outer ring of the tapered roller bearing to prevent the pre-tightening nut from loosening.

[0014] Preferably, an eccentric pin for changing the pitch of the propeller is installed on one side of the root of the blade.

[0015] Compared with the prior art, the utility model has achieved the following technical effects:

[0016] The utility model provides a connection structure between a propeller blade and a propeller hub, wherein a centripetal thrust ball bearing is installed between the outer wall of the blade root and the inner wall of the propeller hub, a tapered roller bearing is installed on the outer periphery of the blade and is arranged close to the cuff of the propeller hub to ensure the connection between the blade and the propeller hub, a limit holding assembly is located between the propeller hub and the blade, and the limit holding assembly is located between the centripetal thrust ball bearing and the tapered roller bearing, a pressure oil cavity is formed between the limit holding assembly and the inner wall of the propeller hub, and a pre-tightening element can be detachably installed on the outer periphery of the tapered roller bearing; after the centripetal thrust ball bearing is completed, After the bearing is installed, high-pressure oil is introduced into the pressure oil chamber to give the outer ring of the tapered roller bearing a movement tendency away from the propeller root. Due to the cone angle of the tapered roller bearing, the outer ring of the tapered roller bearing will expand radially. The radial expansion eliminates the gap between the blade and the hub. At this time, tightening the pre-tightening element can ensure reliable contact between the blade and the hub when the propeller is working. This operation method can ensure that the high-speed rotating propeller can still be accurately positioned and reliably connected under complex working conditions such as dynamic and static loads, high and low temperature impacts, etc., to achieve field assembly and disassembly operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic structural diagram of the connection structure between the propeller blades and the hub in the present invention;

[0019] Figure 2 This is a partial structural diagram of the connection structure between the propeller blades and the hub in the present invention;

[0020] Figure 3 This is a schematic diagram of the installation of the blades and the hub in the utility model;

[0021] In the figure: 1-blade, 2-tapered roller bearing, 3-preload nut, 4-anti-wear pad, 5-lightning conductor, 6-bushing, 7-sealing ring, 8-support frame, 9-retaining frame, 10-centrifugal thrust ball bearing, 11-bearing inner ring clamp, 12-wire retaining ring, 13-eccentric pin, 14-hub, 15-bearing washer. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] The purpose of the utility model is to provide a connection structure between a propeller blade and a hub, so as to solve the problems existing in the prior art and realize accurate positioning and reliable connection between the propeller blade and the hub.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0025] like Figure 1-Figure 3 As shown, this embodiment provides a connection structure between a propeller blade and a hub, including a centripetal thrust ball bearing 10, a tapered roller bearing 2, a limit holding assembly and a preload element. The centripetal thrust ball bearing 10 is installed between the outer wall of the blade root of the blade 1 and the inner wall of the hub 14. The tapered roller bearing 2 is installed on the outer periphery of the blade 1 and is arranged close to the cuff of the hub 14 to ensure the connection between the blade 1 and the hub 14. The limit holding assembly is located between the hub 14 and the blade 1, and the limit holding assembly is located between the centripetal thrust ball bearing 10 and the tapered roller bearing 2. A pressurized oil chamber is formed between the limit holding assembly and the inner wall of the hub 14, and the preload element can be removably installed. Installed on the outer circumference of the tapered roller bearing 2; after the installation of the centripetal thrust ball bearing 10 is completed, high-pressure oil is introduced into the pressurized oil chamber to give the outer ring of the tapered roller bearing 2 a movement trend away from the propeller root direction. Due to the cone angle of the tapered roller bearing 2, the outer ring of the tapered roller bearing 2 produces radial expansion, and the radial expansion eliminates the gap between the blade 1 and the hub 14. At this time, tightening the pre-tightening element can ensure reliable contact between the blade 1 and the hub 14 when the propeller is working. This operation method can ensure that the high-speed rotating propeller can still be accurately positioned and reliably connected under complex working conditions such as dynamic and static loads, high and low temperature impacts, etc., to achieve field assembly and disassembly operability.

[0026] Specifically, the radial thrust ball bearing 10 and the tapered roller bearing 2 are both split bearings.

[0027] A bearing washer 15 is provided between the outer wall of the centripetal thrust ball bearing 10 and the inner wall of the hub 14 . The bearing washer 15 is made of a non-metallic material.

[0028] The outer ring of centripetal thrust ball bearing 10 is mounted on bearing washer 15, which is installed between the outer ring of centripetal thrust ball bearing 10 and the inner wall of hub 14. The inner ring of centripetal thrust ball bearing 10 is fixed to the outer periphery of the blade root of blade 1 via bearing inner ring clamp 11 and wire retaining ring 12, allowing blade 1 to rotate relative to hub 14. Centripetal thrust ball bearing 10 primarily bears the centrifugal load generated by the rotation of blade 1. Bearing washer 15 prevents direct contact between the outer ring of centripetal thrust ball bearing 10, made of alloy steel, and hub 14, made of aluminum alloy, which could cause electrochemical corrosion in hot and humid environments. Furthermore, the inner and outer surfaces of bearing washer 15 are coated with glue to eliminate the gap between centripetal thrust ball bearing 10 and hub 14.

[0029] The limit retaining assembly includes a retainer 9, a support frame 8 and a sealing ring 7. The retainer 9 and the support frame 8 are both sleeved on the outer periphery of the blade 1, and one end of the retainer 9 contacts one side of the centripetal thrust ball bearing 10, and the other end of the retainer 9 abuts one side of the support frame 8, and the other side of the support frame 8 abuts one side of the tapered roller bearing 2, which can ensure a tight fit between the various structures. A pressure oil chamber is formed between the outer wall of the support frame 8 and the hub 14. The sealing ring 7 is installed on the outer wall of the support frame 8, and a sealing ring 7 is provided on each side of the pressure oil chamber, thereby sealing the inside of the pressure oil chamber at both ends of the pressure oil chamber, which not only ensures the application of pressure but also avoids leakage of high-pressure oil. As a specific option, the sealing ring 7 is a coated O-ring or a dumbbell-shaped sealing ring.

[0030] The support frame 8 includes a first support section and a second support section. The outer diameter of the first support section is smaller than the outer diameter of the second support section, and one end of the first support section abuts against one end of the retaining frame 9. The other end of the first support section is integrally formed with one end of the second support section, thereby forming a pressurized oil chamber on one side of the second support section. The other end of the second support section abuts against one end of the tapered roller bearing 2. A special hydraulic pump is used to pressurize high-pressure oil into the pressurized oil chamber. As the pressure in the pressurized oil chamber increases, the oil pressure can act on one side of the second support section, thereby giving the second support section a pressure that always leans against the pressure. The second support section transmits the movement trend toward the tip of the blade 1 to the outer ring of the tapered roller bearing 2, so that the outer ring of the tapered roller bearing 2 has a movement trend toward the tip of the blade 1. Since the centripetal thrust ball bearing 10 has fixed the axial position of the blade 1, the tapered roller bearing 2 has a cone angle, so that the outer ring of the tapered roller bearing 2 expands radially, and then is fixed with the preload element, so as to realize the reliable positioning and safe operation of the propeller blade 1 and the blade sleeve. At the same time, the oil chamber is pressurized to fill / depressurize, so that the assembly / disassembly of the blade 1 is reliable and safe.

[0031] An annular protrusion is provided on the inner wall of the hub 14 at a position corresponding to the retaining frame 9, and one end of the annular protrusion can extend to the outer wall of a portion of the first support section. A pressurized oil chamber is formed between one side of the annular protrusion, the inner wall of the hub 14, the first support section and one side of the second support section; a sealing ring 7 is provided between the outer wall of the first support section and the inner wall of the annular protrusion, and between the outer wall of the second support section and the inner wall of the hub 14 to achieve sealing of the pressurized oil chamber.

[0032] The outer ring of the tapered roller bearing 2 and the support frame 8 are press-fitted together through interference fit. The tapered roller bearing 2 mainly bears the aerodynamic bending moment of the blade 1.

[0033] This embodiment also includes a bushing 6, a lightning conductor 5 and an anti-wear pad 4. The bushing 6 and the lightning conductor 5 are both sleeved on the outer circumference of the tapered roller bearing 2 and located between the tapered roller bearing 2 and the hub 14. The lightning conductor 5 is located on the side of the bushing 6 away from the blade 1. The anti-wear pad 4 is located between the preload element and the end face of the hub 14. The bushing 6 and the anti-wear pad 4 are both made of non-metallic materials. The bushing 6 can ensure the accurate positioning and reliable connection of the blade 1 and the hub 14 under static and dynamic load conditions. The anti-wear pad 4 can prevent the blade root made of alloy steel from directly contacting the hub 14 made of aluminum alloy and causing electrochemical corrosion in a humid and hot environment. By placing the lightning conductor 5 between the blade root and the blade sleeve, and with the help of the lightning protection tape laid on the surface of the blade 1, a good lightning current path from the propeller tip to the engine is formed, thereby realizing the propeller lightning protection design.

[0034] The pre-tightening element includes a pre-tightening nut 3 and an anti-loosening element. The pre-tightening nut 3 is connected to the outer ring of the tapered roller bearing 2 through a thread, and the anti-loosening element is installed on the pre-tightening nut 3 and the outer ring of the tapered roller bearing 2 to prevent the pre-tightening nut 3 from loosening.

[0035] The eccentric pin 13, which enables blade 1 to change pitch, is integrated into the root of blade 1. Combined with the split tapered roller bearing 2 and the radial thrust ball bearing 10, blade 1 is connected to hub 14, making it possible to disassemble and assemble blade 1 in the field. At the same time, the above design allows the propeller to automatically change pitch, meaning blade 1 can rotate freely within the sleeve of hub 14, allowing the installation angle of blade 1 to increase or decrease according to flight conditions, ensuring that the propeller is in favorable operating conditions during takeoff, climb, cruise, descent, and other operating conditions.

[0036] In this embodiment, in order to ensure that a lightning current path is formed between the composite blade 1 and the hub 14, lightning protection tapes are laid on the working surface and non-working surface of the blade 1. One end of the lightning protection tape is connected to the nickel leading edge shield at the tip of the blade 1, and the other end is connected to the metal root of the blade 1; through the connection structure between the blade 1 and the hub 14, a double insurance lightning protection structure is realized between the root and the hub 14.

[0037] The first path is blade 1 lightning protection webbing - blade root - eccentric pin 13 - pull sleeve - oil pipe assembly - propeller hub 14 - engine;

[0038] The second path is blade 1 lightning protection tape - blade root - tapered roller bearing 2 - lightning conductor 5 - propeller hub 14 - engine;

[0039] Through the above-mentioned design, this embodiment successfully achieves a reliable connection between the composite blade 1 and the aluminum alloy hub 14. While ensuring the pitch change function and field disassembly and assembly, it also takes into account the setting of the lightning current path and the protection of the dissimilar metal connection, thereby improving the safety of the entire propeller.

[0040] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A connection structure between a propeller blade and a hub, characterized in that: The invention comprises a centripetal thrust ball bearing, a tapered roller bearing, a limit retaining assembly and a pre-tightening element, wherein the centripetal thrust ball bearing is installed between the outer wall of the blade root and the inner wall of the hub, the tapered roller bearing is installed on the outer periphery of the blade and is arranged close to the cuff of the hub, the limit retaining assembly is located between the hub and the blade, and the limit retaining assembly is located between the centripetal thrust ball bearing and the tapered roller bearing, a pressure oil chamber is formed between the limit retaining assembly and the inner wall of the hub, and the pre-tightening element can be detachably installed on the outer ring of the tapered roller bearing; after the installation of the centripetal thrust ball bearing is completed, high-pressure oil is introduced into the pressure oil chamber to give the outer ring of the tapered roller bearing a movement tendency away from the blade root direction, and due to the tapered roller bearing having a cone angle, the outer ring of the tapered roller bearing expands radially, and tightening the pre-tightening element to fix it at this time can eliminate the gap between the blade and the hub.

2. The connection structure between a propeller blade and a hub according to claim 1, characterized in that: The centripetal thrust ball bearing and tapered roller bearing are both split bearings.

3. The connection structure between a propeller blade and a hub according to claim 1, characterized in that: The limit retaining assembly includes a retaining frame, a support frame and a sealing ring. The retaining frame and the support frame are both sleeved on the outer circumference of the blade, and one end of the retaining frame contacts one side of the centripetal thrust ball bearing, the other end of the retaining frame abuts one side of the support frame, and the other side of the support frame abuts one side of the tapered roller bearing. The pressure oil chamber is formed between the outer wall of the support frame and the hub, the sealing ring is installed on the outer wall of the support frame, and a sealing ring is provided on each side of the pressure oil chamber.

4. The connection structure between a propeller blade and a hub according to claim 3, characterized in that: The support frame includes a first support section and a second support section, the outer diameter of the first support section is smaller than the outer diameter of the second support section, and one end of the first support section abuts one end of the retaining frame, the other end of the first support section is integrally formed with one end of the second support section, and the other end of the second support section abuts one end of the tapered roller bearing; the inner wall of the hub is provided with an annular protrusion at a position corresponding to the retaining frame, one end of the annular protrusion can extend to the outer wall of a portion of the first support section covering the first support section, one side of the annular protrusion, the inner wall of the hub, the first support section and one side of the second support section form the pressurized oil chamber; the sealing ring is provided between the outer wall of the first support section and the inner wall of the annular protrusion, and between the outer wall of the second support section and the inner wall of the hub.

5. The connection structure between a propeller blade and a hub according to claim 3, characterized in that: The outer ring of the tapered roller bearing and the support frame are press-fitted together through interference fit.

6. The connection structure between a propeller blade and a hub according to claim 1, characterized in that: A bearing washer is provided between the outer ring of the centripetal thrust ball bearing and the inner wall of the hub, and the bearing washer is made of non-metallic material.

7. The connection structure between a propeller blade and a hub according to claim 1, characterized in that: It also includes a bushing, a lightning conductor and an anti-wear pad. The bushing and the lightning conductor are both sleeved on the outer circumference of the tapered roller bearing and located between the tapered roller bearing and the hub. The lightning conductor is located on the side of the bushing away from the root of the blade. The anti-wear pad is located between the preload element and the end face of the hub. The bushing and the anti-wear pad are both made of non-metallic materials.

8. The connection structure between a propeller blade and a hub according to claim 1, characterized in that: The pre-tightening element includes a pre-tightening nut and an anti-loosening element. The pre-tightening nut is connected to the outer ring of the tapered roller bearing through a thread, and the anti-loosening element is installed on the pre-tightening nut and the outer ring of the tapered roller bearing to prevent the pre-tightening nut from loosening.

9. The connection structure between a propeller blade and a hub according to claim 1, characterized in that: An eccentric pin for changing the pitch of the propeller is installed on one side of the propeller root of the blade.

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