CN111911529B - Forming die and method for manufacturing high-bearing self-lubricating spherical plain bearing by using same - Google Patents

Abstract

The invention relates to a forming die which comprises a left die, a right die, a mandrel and a compression nut. An axial through hole I and a joint bearing outer ring positioning hole I are formed in the left die, and a sealing ring I is installed in the joint bearing outer ring positioning hole I; a spherical surface hole I is formed in the sealing ring I; an axial through hole II and a joint bearing outer ring positioning hole II are formed in the right die, and a sealing ring II is arranged in the joint bearing outer ring positioning hole II; the sealing ring II is provided with a spherical hole II, an injection hole I and an exhaust hole I; an injection hole II and an exhaust hole II are formed in the right die; the mandrel sequentially passes through the right die, the inner hole of the joint bearing inner ring and the left die to be connected with the compression nut, so that a closed injection cavity is formed. The invention also discloses a method for manufacturing the high-bearing self-lubricating spherical plain bearing by adopting the die. The invention can improve the bearing capacity of the joint bearing, and the manufactured self-lubricating joint bearing has good self-lubricating performance and maintenance-free capacity.

Description

Forming die and method for manufacturing high-bearing self-lubricating spherical plain bearing by using same

Technical Field

The invention relates to the field of aviation, in particular to a forming die and a method for manufacturing a high-bearing self-lubricating spherical plain bearing by using the same.

Background

The high-bearing self-lubricating joint bearing in the aviation field is a joint bearing with a self-lubricating wear-resistant liner material in a gap between an outer ring and an inner ring of the bearing, is widely applied to swinging parts of an airplane body, a flaperon, an undercarriage and the like, and has good low-friction torque and maintenance-free capacity. The manufacturing method of the high-bearing self-lubricating spherical plain bearing is a core technology of the high-bearing self-lubricating spherical plain bearing. At present, self-lubricating joint bearings applied to high-bearing maintenance-free aviation mostly adopt self-lubricating long fiber fabric type composite materials as wear-resistant liners.

Along with the continuous improvement of aeronautical system to self-lubricating joint bearing performance and reliability requirement, regard the self-lubricating joint bearing of wear-resisting liner with long fiber fabric type combined material, its defect has exposed gradually, specifically includes: form and position tolerance of the inner surface of the outer ring is difficult to accurately control, and phenomena of uneven abrasion of the liner, falling off of the edge of the liner and the like often occur in the using process, so that local abrasion of the liner is aggravated, and the fit clearance of the bearing is overlarge. In addition, the traditional high-bearing self-lubricating knuckle bearing forming method can damage the gasket, not only influences the mechanical strength and the bonding strength of the gasket, but also reduces the bearing capacity, the reliability and the service life of the knuckle bearing.

With the development of new technology in recent years, countries such as the united states and japan have developed self-lubricating spherical plain bearings using reinforced polymer materials as wear-resistant liners and applied to the field of aviation industry, such spherical plain bearings not only can achieve good bonding between the liners and the inner surface of the outer ring or the outer surface of the inner ring, but also have good bearing resistance and wear resistance; the knuckle bearing manufactured by the technology has small starting torque, stable friction coefficient in the operation process and flexibly adjustable thickness of the liner, overcomes the defects of a fabric liner type self-lubricating bearing, and can meet different technical requirements of the aviation industry. US4053665, US4033019 and US4048370 relate to a method for manufacturing a self-lubricating moulding oscillating bearing, in which a cavity is made between the inner and outer races of the oscillating bearing, into which a self-lubricating liner material can be injected, and the outer race of the oscillating bearing is provided with through injection holes and exhaust holes, the inner and outer races of the oscillating bearing are placed in a mould, and the self-lubricating oscillating bearing is manufactured by injection moulding of the self-lubricating material. In the method, because the injection hole and the exhaust hole are formed on the outer ring of the joint bearing, the bearing capacity of the joint bearing is reduced, and the main bearing part needs to avoid the positions of the injection hole and the exhaust hole when the bearing is installed, so that the wide application of the bearing is limited to a certain extent. CN110131307A relates to a method for manufacturing a molding type self-lubricating spherical plain bearing, which comprises the steps of using nylon as an auxiliary liner layer, assembling an outer ring semi-finished product and an inner ring, then carrying out extrusion molding to form a spherical plain bearing molding liner injection cavity, and then filling a lubricating material in the cavity; the method has the defects that the friction force between the outer ring and the inner wall of the forming die is large, the deformation of the outer ring is large, and the nylon generates severe plastic deformation due to the extremely large contact stress in the forming process, so that the gap uniformity of a bearing cavity cannot be ensured, and the uniformity, the integrity and the compactness of a filling lubricating material can be influenced. CN110159655A relates to a method for manufacturing a self-lubricating radial spherical plain bearing of a molding type, which comprises performing extrusion molding on an outer ring semi-finished product having a through hole and a flange and an inner ring, and attaching the flange of the through hole of the outer ring to the spherical surface of the inner ring by extrusion to form a cavity filled with a lubricating material. The method has the disadvantages that the forming process is complicated, the inner ring outer spherical surface which is contacted with the outer ring flange in the extrusion forming process is easy to be damaged, the thickness uniformity of the cavity is difficult to ensure, and the manufacturing yield is low.

Disclosure of Invention

The invention aims to provide a forming die capable of improving bearing capacity of a joint bearing.

The invention also provides a method for manufacturing the high-bearing self-lubricating spherical plain bearing by adopting the forming die.

In order to solve the above problems, the present invention provides a molding die, which is characterized in that: the die comprises a left die, a right die, a mandrel and a compression nut; an axial through hole I and a joint bearing outer ring positioning hole I are respectively formed in the left die, and a sealing ring I is arranged in the joint bearing outer ring positioning hole I; a spherical surface hole I is formed in the sealing ring I; an axial through hole II and a joint bearing outer ring positioning hole II are respectively formed in the right die, and a sealing ring II is arranged in the joint bearing outer ring positioning hole II; the sealing ring II is provided with a spherical hole II, and an injection hole I and an exhaust hole I which are distributed oppositely at 180 degrees; an injection hole II and an exhaust hole II which are oppositely distributed at 180 degrees are formed in the right die; the mandrel sequentially penetrates through the right die, the inner holes of the inner rings of the joint bearings and the left die to be connected with the compression nut, so that a closed injection cavity is formed.

The diameter of the locating hole I of the outer ring of the joint bearing is the same as that of the outer cylindrical surface I of the sealing ring I, and the locating hole I of the outer ring of the joint bearing is equal to that of the cylindrical surface I of the outer ring of the joint bearing.

And the diameter of the positioning hole II of the outer ring of the joint bearing is the same as that of the outer cylindrical surface II of the sealing ring II and is equal to that of the cylindrical surface I of the outer ring of the joint bearing.

The depth of the joint bearing outer ring positioning hole I is the same as that of the joint bearing outer ring positioning hole II, and the depth is larger than the thickness of the sealing ring I or the sealing ring II and smaller than the sum of the thickness of the sealing ring I or the sealing ring II and the height of the 1/2 joint bearing outer ring.

The diameter of the injection hole I is the same as that of the injection hole II.

The hole diameters of the exhaust hole I and the exhaust hole II are the same.

The aperture of the injection hole I or the injection hole II is larger than that of the exhaust hole I or the exhaust hole II.

The radius of the spherical surface hole I and the radius of the spherical surface hole II are the same as that of the outer spherical surface of the inner ring of the joint bearing.

And the end face I of the sealing ring I and the end face II of the sealing ring II are tightly attached to the end face III and the end face IV of the outer ring of the joint bearing.

The method for manufacturing the high-bearing self-lubricating spherical plain bearing by adopting the forming die comprises the following steps:

processing the inner surface of a blank of an outer ring of a joint bearing to prepare a semi-finished product of the joint bearing; then processing the outer surface of the inner ring of the joint bearing to obtain a semi-finished product of the joint bearing to be injection molded;

sequentially mounting a right die containing a sealing ring II, the processed joint bearing semi-finished product and a left die containing the sealing ring I on a mandrel, and then screwing a compression nut at the other end to form a closed injection cavity;

injecting a lubricating material into the injection cavity, and stopping injection after the lubricating material overflows from the exhaust hole II to obtain the molding gasket;

placing the die containing the knuckle bearing obtained in the step three into a high-pressure heating container, sealing the container, and filling nitrogen, wherein the pressure is controlled to be 0.5-2.5 MPa, the ambient temperature is 50-120 ℃, and the retention time is 30-90 min;

taking the mold containing the knuckle bearing obtained in the step out of the high-pressure heating container, loosening the compression nut, taking out the knuckle bearing, and rotating the inner ring of the knuckle bearing to separate the knuckle bearing from the molding gasket;

sixthly, placing the knuckle bearing in a drying oven, heating to 170 ℃ at a heating rate of 1 ℃/min, preserving heat for 24 hours, carrying out curing treatment, and then naturally cooling to room temperature along with the oven to obtain the high-bearing self-lubricating knuckle bearing.

Compared with the prior art, the invention has the following advantages:

1. the invention injects the lubricating material into the cavity from the end face of the injection cavity of the molding liner, the outer ring of the knuckle bearing has no injection hole and exhaust hole, the thickness of the molding liner is uniform, the bearing capacity of the knuckle bearing is improved, the manufacturing process of the self-lubricating molding liner knuckle bearing is simplified, the bearing can be freely installed at 360 degrees, the position of the bearing part does not need to avoid the position of the hole, and the installation is convenient. In addition, the injection hole and the exhaust hole are oppositely arranged at the same side of a cavity formed by the inner spherical surface of the outer ring and the outer spherical surface of the inner ring of the knuckle bearing at 180 degrees, so that the part with the largest injection molding difficulty can be completely and compactly filled.

2. The static bearing capacity of the self-lubricating spherical plain bearing manufactured by the die can reach more than 400 MPa. The dynamic load of 250MPa and the swinging life requirement of 25000 times can be met in a room temperature environment, and the abrasion depth of the liner is not more than 0.11mm after operation.

3. The self-lubricating joint bearing outer ring manufactured by the die has no injection hole and exhaust hole, has good self-lubricating performance and maintenance-free capability, and can be used for swinging parts of an aircraft body, a flaperon, an undercarriage and the like.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a schematic structural view of a self-lubricating spherical plain bearing forming die of the invention.

FIG. 2 is a schematic structural view of a left mold sealing ring of the self-lubricating spherical plain bearing forming mold of the invention.

FIG. 3 is a schematic structural view of a right mold sealing ring of the self-lubricating spherical plain bearing forming mold of the invention.

FIG. 4 is a schematic structural view of a left die of the self-lubricating spherical plain bearing forming die.

FIG. 5 is a schematic diagram of the structure of the right die of the self-lubricating spherical plain bearing forming die.

FIG. 6 is a schematic structural view of a mandrel of the self-lubricating spherical plain bearing forming die.

Fig. 7 is a schematic view of the joint bearing structure with the mold liner injection cavity of the present invention.

Fig. 8 is a schematic structural view of the high-load self-lubricating joint bearing of the present invention.

FIG. 9 shows the oscillating friction wear performance of the high-load self-lubricating spherical plain bearing of the present invention.

In the figure: 1-joint bearing outer ring; 11-end face iii; 12-end face IV; 13-inner surface of outer ring; 14-cylinder i; 2-joint bearing inner ring; 21-inner ring outer spherical surface; 22-inner bore; 3-injection molding cavity; 4-a molded gasket; 5, sealing a ring I; 51-end face V; 52-end face I; 53-outer cylindrical surface I; 54-spherical hole i; 6-sealing ring II; 61-end face VI; 62-end face II; 63-outer cylindrical surface ii; 64-spherical hole II; 65-exhaust hole I; 66-injection hole I; 7, a left die; 71-a joint bearing outer ring positioning hole I; 72-end surface of positioning hole of left die; 73-axial through hole I; 8, a right die; 81-joint bearing outer ring positioning hole II; 82-end surface of positioning hole of right mold; 83-axial through hole II; 84-exhaust hole II; 85-injection hole II; 9-mandrel; 91-cylindrical surface II; 92-an axial locating end face; 10-compression nut.

Detailed Description

In the description of the present invention, it should be construed that the terms "left", "right", "inside", "outside", and the like indicate orientations or positional relationships based on the orientations and positional relationships shown in the drawings, for convenience in describing the present invention and simplifying the description, and thus, should not be construed as limiting the present invention.

As shown in fig. 1 to 7, a forming die comprises a left die 7, a right die 8, a mandrel 9 and a compression nut 10.

An axial through hole I73 and a joint bearing outer ring positioning hole I71 are respectively formed in the left die 7, and a sealing ring I5 is installed in the joint bearing outer ring positioning hole I71; a spherical surface hole I54 is formed in the sealing ring I5; an axial through hole II 83 and a joint bearing outer ring positioning hole II 81 are respectively formed in the right die 8, and a sealing ring II 6 is installed in the joint bearing outer ring positioning hole II 81; a spherical surface hole II 64 is formed in the sealing ring II 6, and an injection hole I66 and an exhaust hole I65 which are distributed oppositely at 180 degrees are formed in the sealing ring II 6; an injection hole II 85 and an exhaust hole II 84 which are oppositely distributed at 180 degrees are formed in the right die 8; the mandrel 9 sequentially passes through the right die 8, the inner hole 22 of the joint bearing inner ring 2 and the left die 7 to be connected with the compression nut 10 to form a closed injection cavity 3.

Wherein: the diameter of the joint bearing outer ring positioning hole I71 is the same as that of the outer cylindrical surface I53 of the sealing ring I5 and is equal to that of the cylindrical surface I14 of the joint bearing outer ring 1.

And the diameter of the joint bearing outer ring positioning hole II 81 is the same as that of the outer cylindrical surface II 63 of the sealing ring II 6 and is equal to that of the cylindrical surface I14 of the joint bearing outer ring 1.

The depth of the joint bearing outer ring positioning hole I71 is the same as that of the joint bearing outer ring positioning hole II 81, and the depth is larger than the thickness of the sealing ring I5 or the sealing ring II 6 and smaller than the sum of the thickness of the sealing ring I5 or the sealing ring II 6 and the height of the 1/2 joint bearing outer ring.

The diameter of the injection hole I66 is the same as that of the injection hole II 85.

The diameter of the vent I65 is the same as that of the vent II 84.

The aperture of the injection hole I66 or the injection hole II 85 is larger than that of the exhaust hole I65 or the exhaust hole II 84.

The radius of the spherical surface hole I54 and the radius of the spherical surface hole II 64 are the same as that of the outer spherical surface 21 of the joint bearing inner ring 2, and the spherical centers of the three parts are superposed after assembly.

The end face I52 of the sealing ring I5 and the end face II 62 of the sealing ring II 6 are tightly attached to the end face III 11 and the end face IV 12 of the knuckle bearing outer ring 1.

The sealing ring I5 and the sealing ring II 6 are made of high polymer materials with low surface energy, and comprise polytetrafluoroethylene, polyformaldehyde and engineering plastics sprayed with an anti-adhesion coating.

And the fit clearance of the axial through hole I73, the axial through hole II 83, the inner hole 22 of the joint bearing inner ring 2 and the cylindrical surface II 91 of the mandrel 9 is 0.01-0.02 mm.

The method for manufacturing the high-bearing self-lubricating spherical plain bearing by adopting the forming die comprises the following steps:

processing the inner surface of a blank of an outer ring 1 of a joint bearing to prepare a semi-finished product of the joint bearing; and then processing the outer surface of the joint bearing inner ring 2 to obtain a joint bearing semi-finished product to be injection molded.

Wherein: sand blasting is carried out on the inner surface of a blank of the outer ring 1 of the oscillating bearing, and the surface roughness is greater than Ra1.6; passivating by using a nitric acid solution containing sodium dichromate; and then coating a primer which is beneficial to improving the bonding force of the gasket on the inner surface 13 of the outer ring.

The outer spherical surface 21 of the inner ring 2 of the joint bearing is cleaned by scrubbing with acetone and coated with a release agent.

The right die 8 containing a sealing ring II 6, the processed joint bearing semi-finished product and the left die 7 containing a sealing ring I5 are sequentially mounted on the mandrel 9, the axial positioning end face 92 of the mandrel 9 does not shield the injection hole II 85 and the exhaust hole II 84 of the right die 8, then the other end compression nut 10 is screwed, the left die positioning hole end face 72 and the right die positioning hole end face 82 are respectively attached to the end face V51 and the end face VI 61, and the inner ring outer spherical surface 21, the outer ring inner surface 13, the end face I52 and the end face II 62 form the closed injection cavity 3.

The joint bearing outer ring positioning hole I71 and the joint bearing outer ring positioning hole II 81 are coaxial with the corresponding axial through hole I73 and the axial through hole II 83, have the same aperture and depth, and the depth of the positioning hole is 3mm greater than the height of the sealing ring I5 or the sealing ring II 6.

After the installation is finished, the spherical centers of the spherical holes I54 and II 64 are superposed with the spherical center of the outer spherical surface 21, the end surface I52 is attached to the end surface III 11, and the end surface II 62 is closely attached to the end surface IV 12, so that the sealing reliability is ensured.

The injection hole II 85 and the exhaust hole II 84 are respectively aligned with the injection hole I66 and the exhaust hole I65 and are right opposite to the right end face of the injection cavity 3, the diameter of the injection hole is 1.5mm, and the diameter of the exhaust hole is 1 mm.

Injecting a lubricating material into the injection cavity 3, stopping injecting after a large amount of lubricating material overflows from the exhaust hole II 84, and obtaining the molding liner 4, and ensuring that the molding liner 4 is complete and has no air holes.

The lubricating material is mainly composed of a thermosetting resin and chopped fibers. Wherein: the thermosetting resin is one or two of epoxy resin, acrylate resin, vinyl resin, phenolic resin and polyimide resin. The chopped fiber is one or two of glass fiber, carbon fiber, aramid fiber, poly-p-phenylene benzobisoxazole fiber, potassium titanate whisker and the like.

Fourthly, placing the die containing the knuckle bearing obtained in the step three into a high-pressure heating container, sealing the container, and filling nitrogen, wherein the pressure is controlled to be 0.5-2.5 MPa, the ambient temperature is 50-120 ℃, and the retention time is 30-90 min.

Fifthly, taking the mold containing the knuckle bearing obtained in the step four out of the high-pressure heating container, loosening the compression nut 10, taking out the knuckle bearing, and rotating the inner ring of the knuckle bearing to separate the knuckle bearing from the molding pad 4;

sixthly, placing the knuckle bearing in a drying oven, heating to 170 ℃ at a heating rate of 1 ℃/min, preserving heat for 24 hours, carrying out curing treatment, and then naturally cooling to room temperature along with the oven to obtain the high-bearing self-lubricating knuckle bearing without the injection hole and the exhaust hole in the outer ring, wherein the high-bearing self-lubricating knuckle bearing is shown in fig. 8.

According to the high-bearing self-lubricating spherical plain bearing, the outer ring of the bearing is made of martensite precipitation hardening stainless steel 0Cr17Ni4Cu4Nb4, and the inner ring of the bearing is made of one of high-carbon chromium stainless steel 9Cr18Mo or precipitation hardening stainless steel 0Cr13Ni8Mo2 Al.

The friction and wear performance test under the swing working condition is carried out on the high-bearing self-lubricating joint bearing:

the experimental conditions are as follows: at room temperature, 250MPa, 10cpm, 25000 times and a swinging angle of +/-25 degrees. The results are shown in FIG. 9. The average friction coefficient is 0.087, the maximum abrasion depth is 0.095mm, and the abrasion-resistant service life reaches the requirements of GJB 5502 'Low-speed swinging self-lubricating radial spherical plain bearing Specification'.

Claims (10)

1. A kind of forming die, characterized by: the die comprises a left die (7), a right die (8), a mandrel (9) and a compression nut (10); an axial through hole I (73) and a joint bearing outer ring positioning hole I (71) are respectively formed in the left die (7), and a sealing ring I (5) is installed in the joint bearing outer ring positioning hole I (71); a spherical surface hole I (54) is formed in the sealing ring I (5); an axial through hole II (83) and a joint bearing outer ring positioning hole II (81) are respectively formed in the right die (8), and a sealing ring II (6) is installed in the joint bearing outer ring positioning hole II (81); the sealing ring II (6) is provided with a spherical hole II (64), and is provided with an injection hole I (66) and an exhaust hole I (65) which are oppositely distributed at 180 degrees; an injection hole II (85) and an exhaust hole II (84) which are oppositely distributed at 180 degrees are formed in the right die (8); the mandrel (9) sequentially penetrates through the right die (8), the inner hole (22) of the joint bearing inner ring (2), and the left die (7) to be connected with the compression nut (10) to form a closed injection cavity (3).

2. A molding die as defined in claim 1, wherein: the diameter of the joint bearing outer ring positioning hole I (71) is the same as that of the outer cylindrical surface I (53) of the sealing ring I (5), and is equal to that of the cylindrical surface I (14) of the joint bearing outer ring (1).

3. A molding die as defined in claim 1, wherein: and the diameter of the joint bearing outer ring positioning hole II (81) is the same as that of the outer cylindrical surface II (63) of the sealing ring II (6), and is equal to that of the cylindrical surface I (14) of the joint bearing outer ring (1).

4. A molding die as defined in claim 1, wherein: the depth of the joint bearing outer ring positioning hole I (71) is the same as that of the joint bearing outer ring positioning hole II (81), and the depth is larger than the thickness of the sealing ring I (5) or the sealing ring II (6) and smaller than the sum of the thickness of the sealing ring I (5) or the sealing ring II (6) and the height of the 1/2 joint bearing outer ring.

5. A molding die as defined in claim 1, wherein: the diameter of the injection hole I (66) is the same as that of the injection hole II (85).

6. A molding die as defined in claim 1, wherein: the vent I (65) and the vent II (84) have the same aperture.

7. A molding die as defined in claim 1, wherein: the aperture of the injection hole I (66) or the injection hole II (85) is larger than that of the exhaust hole I (65) or the exhaust hole II (84).

8. A molding die as defined in claim 1, wherein: the spherical surface hole I (54) and the spherical surface hole II (64) are the same as the radius of an outer spherical surface (21) of the joint bearing inner ring (2).

9. A molding die as defined in claim 1, wherein: the end face I (52) of the sealing ring I (5) and the end face II (62) of the sealing ring II (6) are tightly attached to the end face III (11) and the end face IV (12) of the knuckle bearing outer ring (1).

10. The method for manufacturing the high-load-bearing self-lubricating spherical plain bearing by using the forming die as claimed in claim 1, comprising the following steps:

processing the inner surface of a blank of an outer ring (1) of a joint bearing to prepare a semi-finished product of the joint bearing; then, processing the outer surface of the joint bearing inner ring (2) to obtain a joint bearing semi-finished product to be injection molded;

sequentially mounting a right die (8) containing a sealing ring II (6), a processed joint bearing semi-finished product and a left die (7) containing a sealing ring I (5) on a mandrel (9), and then screwing a compression nut (10) at the other end to form a closed injection cavity (3);

injecting a lubricating material into the injection cavity (3), and stopping injection after the lubricating material overflows from the vent hole II (84), so as to obtain the molding pad (4);

placing the die containing the knuckle bearing obtained in the step three into a high-pressure heating container, sealing the container, and filling nitrogen, wherein the pressure is controlled to be 0.5-2.5 MPa, the ambient temperature is 50-120 ℃, and the retention time is 30-90 min;

taking the die containing the knuckle bearing obtained in the step out of the high-pressure heating container, loosening the compression nut (10), taking out the knuckle bearing, and rotating the inner ring of the knuckle bearing to separate the knuckle bearing from the molding pad (4);

sixthly, placing the knuckle bearing in a drying oven, heating to 170 ℃ at a heating rate of 1 ℃/min, preserving heat for 24 hours, carrying out curing treatment, and then naturally cooling to room temperature along with the oven to obtain the high-bearing self-lubricating knuckle bearing.

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