Combined titanium alloy self-lubricating knuckle bearing and assembly method thereof

Abstract

The invention provides a combined type titanium alloy self-lubricating knuckle bearing and an assembling method thereof, and relates to the technical field of aviation bearings, the bearing comprises an inner ring, a fabric gasket and a split type outer ring body, the split type outer ring body comprises a first outer ring and a second outer ring, the fabric gasket is pasted on the inner surface of the first outer ring and the inner surface of the second outer ring, and the fabric gasket is pasted on the outer surface of the first outer ring. And the first outer ring is connected with the second outer ring in a clamping manner. The first outer ring is provided with a clamping groove part, a stepped ring groove is formed in the position of the clamping groove part, the second outer ring comprises a clamping head part, a stepped clamping ring clamped in the stepped ring groove is arranged on the clamping head part, axial force is applied along the axis of the inner ring, the groove end part is pushed, the stepped clamping ring is clamped in the stepped ring groove, and therefore the assembling process of the split type outer ring body is achieved. Due to the structural design of the split type outer ring body, the assembly process of a traditional integrated outer ring is improved, and the gasket can be ensured to be intact after being installed, so that the high-precision control of a clearance is improved, and the operation performance of an airplane is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of aviation bearings, and in particular to a combined titanium alloy self-lubricating spherical bearing and an assembly method thereof. Background Art

[0002] Self-lubricating spherical bearings are used in aviation equipment because of their maintenance-free, high load-bearing and high wear-resistant performance advantages, such as in aircraft landing gear, wing actuators, rotors, control rudders and other core components, and are important basic parts for aviation manufacturing. Figure 1 As shown in the figure, a typical aviation self-lubricating spherical bearing (hereinafter referred to as bearing) mainly includes an inner ring 1', an outer ring 3 and a liner 2' pasted on the inner circumference of the outer ring 3. The inner ring and outer ring are both integral structures, and the liner is a woven composite material of polymer fiber bundles. It cannot withstand the high temperature of metal hot forming during manufacturing. The outer ring can only be assembled to the inner ring 1 by plastic forming at room temperature. This requires that the outer ring material has good plastic deformation ability, and the inner and outer rings are precisely enveloping. The forming cannot cause damage to the inner and outer rings and the liner material, which poses a challenge to the outer ring material. During the bearing forming and assembly process, there are extremely strict requirements on the clearance between the inner and outer rings and the contact pressure on the liner. The higher the strength and the stronger the resilience of the outer ring material, the more difficult it is to form a controllable uniform clearance. At the same time, the greater the forming force of the material, the easier it is to form excessive contact pressure on the liner, and the risk of liner damage and crushing increases, thereby reducing the bearing performance and service life.

[0003] At present, the existing inner and outer ring materials are stainless steel. Although stainless steel has excellent mechanical properties and corrosion resistance, it has good plastic forming ability. However, compared with light alloys, stainless steel has a high density and cannot meet the lightweight requirements of aircraft. For example, the large number of aircraft (each passenger aircraft is equipped with several thousand), resulting in small aircraft capacity and high fuel consumption. At present, most of the structural parts of aircraft are made of titanium alloy. Taking advantage of the low density of titanium alloy, if the joint bearing is made of titanium alloy, the whole machine can be lightweight. At the same time, titanium alloy has the performance advantages of strong corrosion resistance. However, based on the current self-lubricating joint bearing structure, when titanium alloy is used as the material of the inner and outer rings, the outer ring can only be assembled at room temperature by plastic forming. In terms of process, the outer ring is difficult to plastically form, the rebound is large and difficult to control, and the forming force is large, resulting in low clearance accuracy, easy pressure loss and crushing of the liner, and plastic forming causes micro-crack damage inside the titanium alloy material.

[0004] Therefore, the use of titanium alloy materials requires the development of a new type of self-lubricating spherical bearing structure, the design of its inner and outer ring assembly process, and the guarantee of high clearance precision and no damage to the liner in design and manufacturing technology, so as to achieve the lightweight of self-lubricating spherical bearings for aviation. The development of titanium alloy spherical bearing technology is of great significance to the realization of lightweight aircraft, enhanced carrying capacity, reduced fuel consumption and improved comprehensive performance of aircraft. Summary of the invention

[0005] Based on the above-mentioned defects of the prior art, the purpose of the present invention is to provide a combined titanium alloy self-lubricating spherical bearing and an assembly method thereof, which can reduce the weight of existing bearings, achieve lightweight bearings, and ensure high-precision control of clearance and integrity of gaskets, thereby improving the mechanical performance of aircraft operation.

[0006] Specifically, on the one hand, the present invention provides a combined titanium alloy self-lubricating spherical bearing, which includes an inner ring, a liner, and a split outer ring body, wherein the split outer ring body includes a first outer ring and a second outer ring, the fabric liner is pasted on the inner surfaces of the first outer ring and the second outer ring, the first outer ring and the second outer ring are connected by clamping, the first outer ring includes a clamping groove portion, the clamping groove portion is provided with a stepped annular groove, the stepped annular groove includes a first annular groove surface, a second annular groove surface, and a transition groove surface connected to the first annular groove surface and the second annular groove surface, the second outer ring includes a clamping head portion, the clamping head portion is provided with a stepped clamping ring clamped to the stepped annular groove, the stepped clamping ring includes a first convex annular surface, a second convex annular surface, and a transition annular surface connected to the first convex annular surface and the second convex annular surface, the transition groove surface and the transition annular surface are matched and connected to achieve a fixed connection between the first outer ring and the second outer ring of the split outer ring body.

[0007] Preferably, the stepped annular groove further comprises an end face of the groove, the end face of the groove is located on the side of the second annular groove surface away from the transition groove surface, the stepped snap ring further comprises an end face of the ring, the end face of the ring is located on the side of the second convex annular surface away from the transition annular surface, the end face of the groove does not abut against the end face of the ring, the first annular groove surface is parallel to and spaced from the first convex annular surface, the second annular groove surface is parallel to and abuts against the second convex annular surface. The purpose of not low-contacting is to avoid over-positioning and ensure the reliability and firmness of assembly.

[0008] Preferably, the clamping head portion is circumferentially provided with a plurality of rectangular grooves connected to the ring end surface.

[0009] Preferably, the inner circumferential surface of the second outer ring is a circular inclined surface and is tangent to the spherical surface of the outer circumference of the inner ring.

[0010] Preferably, the included angle between the first annular groove surface and the second annular groove surface is a step angle α, the value range of the step angle is 3°≤α≤15°, and the inner diameter of the second annular groove surface close to the transition groove surface is greater than or equal to the inner diameter away from the transition groove surface.

[0011] Preferably, the included angle between the second annular groove surface and the axis of the first outer ring is a guide angle φ, and the value range of the guide angle is 3°≤φ≤15°.

[0012] Preferably, the angle between the transition groove surface and the first outer ring in the radial direction is a transition angle β, and the value range of the transition angle is 0°≤β≤15°; and the angle between the second ring groove surface and the transition groove surface is a stop angle γ, and the value range of the stop angle is 90°≤γ≤115°.

[0013] Preferably, a chamfered right angle D is provided at the connection between the groove end surface and the inner spherical surface of the first inner ring, and the size of the chamfered right angle D is 0.4-0.6 mm.

[0014] Preferably, the fabric liner is made of titanium alloy material.

[0015] On the other hand, the present invention provides a method for assembling a combined titanium alloy self-lubricating spherical plain bearing, which comprises the following steps:

[0016] S1, symmetrically stick the fabric pad to the outer spherical surface of the inner ring, and the second outer ring is sleeved on the inner ring and stuck to the fabric pad;

[0017] S2. The first outer ring is sleeved on the inner ring and moved along its own axis so that the clamping portion of the second inner ring moves into the stepped groove until the transition ring surface abuts against the transition groove surface, thereby completing the assembly of the split outer ring body.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The titanium alloy self-lubricating spherical plain bearing and its assembly method provided by the present invention improve the assembly process of the traditional one-piece outer ring, reduce the assembly difficulty and cost, and ensure the integrity of the gasket after installation, thereby improving the high-precision control of the clearance and significantly improving the operating performance of the aircraft.

[0020] (2) The titanium alloy self-lubricating spherical bearing provided by the present invention realizes comprehensive optimization of the structure, performance and lightweight design of the self-lubricating spherical bearing, reduces manufacturing costs, and provides a strong guarantee for the stable operation of the aircraft. At the same time, the high strength and high corrosion resistance of the titanium alloy further extend the service life of the self-lubricating spherical bearing and effectively reduce maintenance costs.

[0021] (3) In the present invention, when the step angle is in the range of 15°>α≥0°, the guide angle is in the range of 10°≥φ≥5°, the transition angle is in the range of 15°≥β≥0°, and the stop angle is in the range of 115°≥γ≥90°, the risk of damage to the fabric gasket is reduced, the high-precision control of the clearance is improved, and the reliability of the clamping of the first outer ring and the second outer ring is ensured.

[0022] (4) The titanium alloy self-lubricating spherical plain bearing provided by the present invention has the advantages of unique structure, safety, reliability, high efficiency, and green environmental protection.

[0023] (5) By adopting the bearing assembly method of the present invention, the design of the split outer ring body allows the components to be assembled through simple operations such as pasting and moving, without the need for strong plastic forming of the outer ring and extrusion of the gasket, thereby reducing the difficulty and cost of assembly, optimizing the clearance and stress distribution of the bearing, helping to reduce the risk of damage to the fabric gasket due to stress concentration, and improving the accuracy of clearance control. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the existing structure of a self-lubricating spherical plain bearing;

[0025] Figure 2 It is a structural schematic diagram of the combined titanium alloy self-lubricating spherical plain bearing of the present invention;

[0026] Figure 3 yes Figure 2 Partial enlarged view in the middle X direction;

[0027] Figure 4 is a front view of the second outer ring of the present invention;

[0028] Figure 5 yes Figure 4 Middle AA section view;

[0029] Figure 6 The utility model is a schematic diagram of the installation of the combined titanium alloy self-lubricating spherical plain bearing of the present invention.

[0030] Explanation of the reference numerals: 1. inner ring; 2. fabric liner; 4. split outer ring body; 41. first outer ring; 411. clamping groove portion; 4111. stepped annular groove; 41111. first annular groove surface; 41112. second annular groove surface; 41113. transition groove surface; 41114. groove end surface; 412. groove end portion; 42. second outer ring; 421. clamping portion; 4211. stepped clamping ring; 42111. first convex annular surface; 42112. second convex annular surface; 42113. transition annular surface; 42114. ring end surface; 4212. rectangular groove; 422. head end portion. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0032] Reference Figure 2 and Figure 3 The present invention provides a combined titanium alloy self-lubricating spherical bearing, which includes an inner ring 1, a split outer ring body 3 and a fabric liner 2. The inner ring 1 and the split outer ring body 3 are both made of titanium alloy. The fabric liner 2 is pasted on the outer spherical surface of the inner ring 1. The split outer ring body 3 includes a first outer ring 41 and a second outer ring 42. The first outer ring 41 includes a slot portion 411 and a slot end portion 412. The slot portion 411 is provided with a stepped annular groove 4111. The second outer ring 42 includes a clamping portion 421 and a head end portion. The clamping portion 421 is provided with a stepped retaining ring 4211. The second outer ring 42 is sleeved on the inner ring 1 and pasted on the outer periphery of the liner. The head end portion is fixed. The first outer ring 41 is sleeved on the outer periphery of the inner ring 1 and on the opposite side of the second outer ring 42. An axial force is applied along the axis of the inner ring 1 to push the slot end portion 412 so that the stepped retaining ring 4211 is clamped into the stepped annular groove 4111, thereby realizing the assembly process of the split outer ring body 3.

[0033] Since the elastic modulus of titanium alloy is small and the processing deformation is serious, the structural design of the split outer ring body 3 is adopted to improve the assembly process of the traditional integrated outer ring 3, so that the liner can be ensured to be intact after installation, thereby improving the high-precision control of the clearance and significantly improving the operating performance of the aircraft. In addition, the fabric liner 2 made of titanium alloy material is lighter. By adopting the above technical solution, the structure of the self-lubricating spherical bearing is optimized, the applicability of the manufacturing process for titanium alloy materials is met, and high-performance bearings with uniform clearance can be manufactured. During assembly, the liner is first pasted on the outer circumferential arc surface of the inner ring with a hot-melt colloid, and then the second outer ring is sleeved on the outer spherical surface of the inner ring, and the liner and the inner spherical surface of the second outer ring are pasted with a thermosetting colloid. In this way, the inner ring and the second outer ring are effectively fixed. By moving and squeezing the first outer ring, the stepped groove is elastically opened and pressed onto the stepped retaining ring of the second outer ring, so that the two can be accurately connected, and the transition groove surface and the transition ring surface are closely fitted, thereby realizing the assembly process of the split outer ring body. The structural design of this split outer ring body utilizes the good elasticity of titanium alloy materials, improves the difficulties of the plastic forming assembly process of the traditional one-piece outer ring, and ensures the integrity of the liner after installation, thereby improving the high-precision control of the clearance and significantly improving the application performance on the aircraft. In addition, compared with traditional bearing steel, titanium alloy materials are lighter in weight, which plays a very important role in the lightweight design of self-lubricating spherical bearings. At the same time, the high strength and high corrosion resistance of titanium alloys also further extend the service life of self-lubricating spherical bearings and effectively reduce maintenance costs.

[0034] Specifically, the stepped annular groove 4111 includes a first annular groove surface 41111, a second annular groove surface 41112 and a transition groove surface 41113, the transition groove surface 41113 is connected between the first annular groove surface 41111 and the second annular groove surface 41112, the first annular groove surface 41111 is close to the side of the clamping groove portion 411, the angle between the first annular groove surface 41111 and the second annular groove surface 41112 is a step angle α, the angle between the transition groove surface 41113 and the end surface of the groove end portion 412 away from the clamping groove portion 411 is a transition angle β, the angle between the second annular groove surface 41112 and the transition groove surface 41113 is a stop angle γ, and the angle between the second annular groove surface 41112 and the axial direction of the first outer ring 41 is a guide angle φ.

[0035] The stepped annular groove 4111 further includes a groove end surface 41114 , and the groove end surface 41114 is located on a side connected to the second annular groove surface 41112 and away from the transition groove surface 41113 .

[0036] The stepped snap ring 4211 includes a first convex annular surface 42111, a second convex annular surface 42112 and a transition annular surface 42113. The transition annular surface 42113 is connected between the first convex annular surface 42111 and the second convex annular surface 42112. The second convex annular surface 42112 is close to one side of the clamping head 421. When the stepped snap ring 4211 is clamped into the stepped annular groove 4111, the transition annular surface 42113 is tightly fitted with the transition groove surface 41113. The first annular groove surface 41111 is parallel to and spaced from the first convex annular surface 42111, the ring end surface does not abut against the annular groove surface, and the second convex annular surface 42112 abuts against the second annular groove surface 41112, which can better ensure the connection reliability between the transition annular surface and the transition groove surface.

[0037] The stepped retaining ring also includes a ring end face 42114 , which is located on the side of the second convex ring face 42112 away from the transition ring face 42113 , and the groove end face 41114 is not in contact with the ring end face 42114 .

[0038] The first annular groove surface 41111 is parallel to and spaced from the first convex annular surface 42111 , and the second annular groove surface 41112 is parallel to and abuts against the second convex annular surface 42112 , which can better ensure the connection reliability between the transition annular surface 42113 and the transition groove surface 41113 .

[0039] When the step angle is in the range of 15°>α≥0°, and the inner diameter of the second annular groove surface 41112 close to the transition groove surface 41113 decreases along the axis of the inner ring 1 toward a position away from the transition groove surface 41113, it is convenient for the second convex annular surface 42112 to slide into the first annular groove surface 41111 of the first inner ring 1, and can reduce damage to the gasket during the installation process and improve the control accuracy of the clearance.

[0040] When the transition angle is in the range of 15°≥β≥0° and the retaining angle is in the range of 115°≥γ≥90°, the deformation of the clamping joint during installation can be reduced and the reliability of the clamping connection between the first outer ring 41 and the second outer ring 42 can be ensured. This is because when the transition angle is less than 0°, when the second annular groove surface 41112 of the first inner ring 1 is pressed against the transition annular surface 42113 of the second outer ring 42, the transition annular surface 42113 is severely deformed, resulting in poor reliability of the transition annular surface 42113 and the transition groove surface. When the transition angle is too large, the transition groove surface 41113 and the transition annular surface 42113 have poor ability to resist axial loads, increasing the risk of loosening of the clamping joint. Therefore, the transition angle is best within this range.

[0041] When the guide angle is too large, the second convex annular surface 42112 will produce a large deformation during the installation process, causing serious damage to the gasket. When the guide angle is too small, the installation is difficult. Therefore, in order to facilitate the installation of the second outer ring 42 and reduce the risk of damage to the fabric gasket 2, the guide angle is taken in the range of 10°≥φ≥5°.

[0042] In specific applications, for bearings of different sizes, the angle values ​​of α and φ are obtained through calculation and optimization. The calculation results must satisfy the elastic or small deformation state of the material during assembly. When the angle value is too large, the second convex ring surface will produce a large deformation during installation, causing serious damage to the gasket. When the angle value is too small, the installation is difficult. Therefore, appropriate values ​​are conducive to the installation of the second outer ring and reduce the risk of damage to the fabric gasket.

[0043] A chamfered right angle D is provided at the connection between the groove end face 41114 and the inner spherical surface of the first outer ring 41. The size of the chamfered right angle is generally 0.4-0.6 mm, preferably 0.5 mm, to reduce stress concentration in a certain local area during assembly and facilitate assembly.

[0044] Reference Figure 4 and Figure 5 In order to facilitate the clamping head 421 of the second outer ring 42 to be clamped in the stepped ring groove of the first inner ring 1, a plurality of rectangular grooves 4212 are provided in the circumferential direction of the clamping head 421 of the second outer ring 42 to communicate with the ring end face 42114, so as to facilitate the installation of the split outer ring body 3. The design of the plurality of rectangular grooves 4212 connecting the ring end faces facilitates the clamping head 421 to be compressed and deformed inward when the clamping head 421 of the second outer ring 42 is clamped in the stepped ring groove of the first inner ring 1, so as to facilitate the installation of the split outer ring body 4.

[0045] When the chuck portion 421 of the second outer ring 42 is installed in the stepped annular groove of the first inner ring 1, in order to reduce the tensile and compressive damage to the liner, the inner circumference of the second outer ring 42 is a circular bevel. When the chuck portion 421 is compressed and shrinks inward, the inner circumference of the second outer ring 42 is tangent to the liner along the outer circumference of the inner ring 1. When the chuck portion 421 of the second outer ring 42 is installed in the stepped annular groove of the first inner ring 1, since the inner circumference of the second outer ring 42 is a conical surface, when the chuck portion is compressed and shrinks inward, the inner circumference of the second outer ring 42 is tangent to the liner along the outer circumference of the inner ring, reducing the tensile and compressive damage to the liner.

[0046] Reference Figure 3 and Figure 6 The assembly method of the aviation pin axle pasted fabric pad 2 of the present application is divided into three steps:

[0047] S1. The second outer ring 42 is sleeved on the inner ring 1 and adhered to the outer periphery of the gasket; the head end is fixed, and the first outer ring 41 is sleeved on the outer periphery of the inner ring 1 and the side opposite to the second outer ring 42; S2. An axial force is applied along the axis of the inner ring 1 to push the groove end 412 so that the stepped retaining ring 4211 is clamped into the stepped ring groove 4111, so that the transition groove surface 41113 and the transition ring surface 42113 are tightly fitted.

[0048] The design of the split outer ring allows the components to be assembled through simple operations such as pasting and moving. There is no need for strong plastic forming of the outer ring and extrusion of the liner, which reduces the difficulty and cost of assembly, optimizes the clearance and stress distribution of the bearing, helps reduce the risk of damage to the fabric liner due to stress concentration, and improves the accuracy of clearance control.

[0049] The above embodiments are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A combined titanium alloy self-lubricating spherical plain bearing, characterized in that: It comprises an inner ring (1), a fabric liner (2) bonded to the outer spherical surface of the inner ring (1), and a split outer ring body (4) sleeved on the fabric liner (2). The split outer ring body (4) comprises a first outer ring (41) and a second outer ring (42) clamped to the first outer ring (41). The first outer ring (41) includes a clamping groove portion (411), the clamping groove portion (411) is provided with a stepped annular groove (4111), the stepped annular groove (4111) includes a first annular groove surface (41111), a second annular groove surface (41112) and a transition groove surface (41113) connecting the first annular groove surface (41111) and the second annular groove surface (41112), The second outer ring (42) comprises a clamping portion (421), the clamping portion (421) is provided with a stepped clamping ring (4211) clamped in the stepped ring groove (4111), the stepped clamping ring (4211) comprises a first convex ring surface (42111), a second convex ring surface (42112) and a transition ring surface (42113) connecting the first convex ring surface (42111) and the second convex ring surface (42112), The transition groove surface (41113) abuts against the transition ring surface (42113) to fix the split outer ring body (4).

2. The combined titanium alloy self-lubricating spherical plain bearing according to claim 1 is characterized in that: The stepped annular groove (4111) further includes a groove end face (41114), which is located on the side of the second annular groove surface (41112) away from the transition groove surface (41113). The stepped retaining ring (4211) further includes a ring end face (42114), which is located on the side of the second convex annular surface (42112) away from the transition annular surface (42113). The groove end face (41114) and the ring end face (42114) do not abut against each other. The first annular groove surface (41111) is parallel to and spaced from the first convex annular surface (42111), and the second annular groove surface (41112) is parallel to and abuts against the second convex annular surface (42112).

3. The combined titanium alloy self-lubricating spherical plain bearing according to claim 2 is characterized in that: The clamping head portion (421) is provided with a plurality of rectangular grooves (4212) in the circumferential direction and connected to the ring end surface (42114).

4. The combined titanium alloy self-lubricating spherical plain bearing according to claim 3 is characterized in that: The inner circumferential surface of the second outer ring (42) is a circular inclined surface and is tangent to the spherical surface of the outer circumference of the inner ring (1).

5. A combined titanium alloy self-lubricating spherical plain bearing according to claim 1 or 4, characterized in that: The included angle between the first annular groove surface (41111) and the second annular groove surface (41112) is a step angle α, the step angle value range is 15°>α≥0°, and the inner diameter of the second annular groove surface (41112) close to the transition groove surface (41113) is greater than or equal to the inner diameter away from the transition groove surface (41113).

6. The combined titanium alloy self-lubricating spherical plain bearing according to claim 5, characterized in that: The included angle between the second annular groove surface (41112) and the axis of the first outer ring (41) is a guide angle φ, and the value range of the guide angle φ is 10°≥φ≥5°.

7. The combined titanium alloy self-lubricating spherical plain bearing according to claim 6 is characterized in that: The angle between the transition groove surface (41113) and the first outer ring (41) in the radial direction is the transition angle β, and the value range of the transition angle β is 15°≥β≥0°, and the angle between the second ring groove surface (41112) and the transition groove surface (41113) is the stop angle γ, and the value range of the stop angle γ is 115°≥γ≥90°.

8. The combined titanium alloy self-lubricating spherical plain bearing according to claim 2, characterized in that: A chamfered right angle D is provided at the connection between the groove end surface (41114) and the inner spherical surface of the first inner ring (1), and the size of the chamfered right angle D is 0.4-0.6 mm.

9. The combined titanium alloy self-lubricating spherical plain bearing according to claim 2, characterized in that: The fabric liner (2) is made of titanium alloy material.

10. An assembly method for the combined titanium alloy self-lubricating spherical plain bearing according to claim 1, characterized in that: It includes the following steps: S1, symmetrically gluing the fabric liner (2) to the outer spherical surface of the inner ring (1), and sleeve-mounting the second outer ring (42) on the inner ring (1) and gluing it to the fabric liner (2); S2. The first outer ring (41) is sleeved on the inner ring (1) and moved along its own axis so that the clamping portion (421) of the second inner ring (1) moves into the stepped groove until the transition annular surface (42113) abuts against the transition groove surface (41113), thereby completing the assembly of the split outer ring body (4).

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