A microfluidic bionic bearing double-lip rubber seal and its preparation method

Abstract

The present invention discloses a microfluidic bionic bearing double-lip rubber seal and a preparation method thereof, including a metal skeleton, foamed fluororubber, matrix fluororubber, and a storage structure; the foamed fluororubber is bonded to the upper side of the metal skeleton and has a microchannel structure inside; the matrix fluororubber is bonded to the lower side of the metal skeleton; the metal skeleton is mutually bonded and wrapped by the foamed fluororubber and the matrix fluororubber to jointly form a storage structure, and the surfaces of the matrix fluororubber and the foamed fluororubber have a fish-scale-like bionic structure, and there are micropores at the low-lying places of the fish-scale-like bionic structure. The present invention can realize the storage and release of lubricating oil or grease according to temperature changes during the working process, convey the lubricating oil or grease, ensure efficient lubrication, and at the same time use the surface structure to reduce wear during the working process and avoid seal failure.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing seals, and particularly relates to a microfluidic bionic bearing double-lip rubber seal and a preparation method thereof. Background Art

[0002] A bearing is a common part in a mechanical system and plays an important role in mechanical work. To improve mechanical efficiency, it is necessary to lubricate the bearing. Furthermore, to protect the internal lubricating grease and lubricating oil of the bearing from leakage and prevent foreign substances in the external environment from entering the bearing, it is necessary to seal the bearing. The sealing effect achieved by using a seal for the bearing is often affected by temperature. The effect achieved by bearing sealing under high-temperature conditions is often not satisfactory. To improve mechanical efficiency, lubricating oil or lubricating grease is often used to lubricate the bearing.

[0003] At present, most of the double-lip seals used in mechanical seals have a simple structure, which is relatively single. Under high-temperature environments, the lubricating oil or lubricating grease is prone to oxidation, the fluidity becomes stronger, and it is easy to overflow. Under long-term rotational work, the surface of the seal will wear, resulting in seal failure. Summary of the Invention

[0004] To solve the problems existing in the prior art, the present invention provides a microfluidic bionic bearing double-lip rubber seal and a preparation method thereof, which can store and release lubricating oil or lubricating grease according to temperature changes during the working process, convey the lubricating oil or lubricating grease, ensure efficient lubrication, and at the same time use the surface structure to reduce wear during the working process and avoid seal failure, solving the problems mentioned in the above background art.

[0005] To achieve the above object, the present invention provides the following technical solution: A microfluidic bionic bearing double-lip rubber seal includes a metal skeleton, foamed fluororubber, matrix fluororubber, and a storage structure; the foamed fluororubber is bonded to the upper side of the metal skeleton and has a microchannel structure inside; the matrix fluororubber is bonded to the lower side of the metal skeleton; the metal skeleton is bonded and wrapped by the foamed fluororubber and the matrix fluororubber to jointly form a storage structure, and the surfaces of the matrix fluororubber and the foamed fluororubber have a fish-scale-like bionic structure, and there are micropores in the low-lying areas of the fish-scale-like bionic structure.

[0006] Preferably, the cross-section of the microchannel structure is in the shape of an irregular hole, and the microchannel structures are crisscrossed with each other inside the foamed fluororubber.

[0007] Preferably, the size of the microchannel structure is in the micrometer level, crisscrossed with each other, interconnected, and connected to the storage structure.

[0008] Preferably, the cross-sectional diameter of the storage structure is greater than 1 / 3 of the cross-sectional size of the seal and less than 2 / 3 of the cross-sectional size of the seal; the cross-section of the storage structure is circular.

[0009] Preferably, the matrix fluororubber comprises the following components in parts by weight: 100-120 parts of rubber raw material, 3-4 parts of active light magnesium oxide, 5-7 parts of calcium hydroxide, 2-3 parts of bisphenol AF, 0.5-1 part of triphenylphosphine chloride BPP, 30-50 parts of N990 carbon black, and 3-6 parts of silica.

[0010] Preferably, the foamed fluororubber comprises the following components in parts by weight: 20-30 parts of fluororubber, 40-60 parts of molecular sieve, 15-30 parts of white carbon black, 4-6 parts of CaCO3, 4-6 parts of high-density polybutene, 3-6 parts of zinc oxide, 1-2 parts of stearic acid, 3-5 parts of resin C5, 4-6 parts of sulfur, 2-4 parts of dicumyl peroxide DCP, and 2-6 parts of foaming agent, totaling 100 parts.

[0011] In addition, to achieve the above object, the present invention also provides the following technical solution: A preparation method of a double-lip rubber seal for a microfluidic bionic bearing, comprising the following steps:

[0012] S1. Prepare matrix fluororubber:

[0013] Raise the temperature of the open mill to 30 °C. After kneading the fluororubber raw material for 5 minutes, successively add magnesium oxide, calcium hydroxide, bisphenol AF, BPP, and carbon black, and thin-pass 10 times; then add silica filler, knead evenly and let stand for 2 hours;

[0014] S2. Prepare foamed fluororubber:

[0015] Crush the fluororubber on the open mill and thin-pass 5 times, successively add zinc oxide, stearic acid, resin C5, molecular sieve, white carbon black, CaCO3, and high-density polybutene; then add sulfur and dicumyl peroxide DCP and knead evenly, and then add the foaming agent and knead evenly;

[0016] S3. Grind both sides of the metal skeleton until the surface is smooth and there are no obvious bumps;

[0017] S4. Put the foamed fluororubber, matrix fluororubber, and metal skeleton into a vulcanizer for hot melt bonding, and vulcanize the fluororubber at the same time;

[0018] S5. Trim the vulcanized fluororubber, and then perform secondary vulcanization.

[0019] Preferably, the kneading temperature in step S2 is 25-35 °C; in the vulcanization in step S4, the vulcanization temperature is 175-180 °C, the time is 8-12 minutes, and the vulcanization pressure is 50-75 MPa.

[0020] Preferably, in the secondary vulcanization step S5, the temperature is 225-235 °C and the vulcanization time is 15-20 h.

[0021] The beneficial effects of the present invention are as follows: in the present invention, as the temperature rises, part of the lubricating oil or grease will be oxidized, and its fluidity increases with the increase of temperature. The change in air pressure difference caused by temperature enables the lubricating oil or grease to enter the internal microchannels of the foamed fluororubber. The microchannels can absorb and release the overflowing lubricating oil or grease; the storage structure temporarily stores the lubricating oil or grease; and the rubber surface of the seal has a bionic structure in the shape of fish scales, which can reduce the impact of friction and wear on the sealing performance. Description of the Drawings

[0022] Figure 1 is the sealing effect diagram of the seal of the present invention;

[0023] Figure 2 is the partial enlarged view of the bionic structure in the shape of fish scales of the present invention;

[0024] Figure 3 is the cross-sectional view of the seal;

[0025] Figure 4 is the enlarged view of the contact surface between the seal and the bearing roller;

[0026] In the figure, 1 - metal skeleton; 2 - foamed fluororubber; 3 - matrix fluororubber; 4 - storage structure; 5 - microchannel structure; 6 - bionic structure in the shape of fish scales; 7 - roller bearing; 8 - intermediate retaining ring; 9 - rubber seal; 10 - roller. Detailed Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Bearings are common parts in mechanical systems. In this embodiment, a self-aligning roller bearing is taken as an example. As Figure 1 shown, the self-aligning roller bearing 7 includes rollers 10 inside, an intermediate retaining ring 8 for restricting the rollers, and a rubber seal 9 for sealing the bearing.

[0029] The present invention provides a double-lip rubber seal for a microfluidic bionic bearing, which can reduce the impact of friction and wear on the sealing performance. As Figure 3As shown in the figure, the rubber seal specifically includes a foamed fluororubber 2, a metal skeleton 1, a matrix fluororubber 3, and a storage structure 4; the foamed fluororubber 2 is bonded to the upper side of the metal skeleton 1 through a vulcanization technique. The foamed fluororubber has a special microchannel structure 5 inside, and the size of the microchannel is in the micron range. The surfaces of the foamed fluororubber and the matrix fluororubber have a fish-scale-like bionic structure 6, as Figure 2 shown. The microchannel is connected to the storage structure. The matrix fluororubber is bonded to the lower side of the metal skeleton through a vulcanization technique. The matrix fluororubber is bonded to the foamed fluororubber. The metal skeleton is wrapped by the foamed fluororubber and the matrix fluororubber. The storage structure 4 is jointly formed by the metal skeleton 1, the foamed fluororubber 2, and the matrix fluororubber 3.

[0030] Furthermore, the foamed fluororubber and the matrix fluororubber are respectively bonded to the surface of the metal skeleton through a hot-melt technique.

[0031] Furthermore, the microchannel structure inside the foamed fluororubber, as Figure 4 shown, the microchannels intersect and penetrate each other vertically and horizontally. With the change of temperature, the microchannels can contract and expand to transport lubricating oil or grease. In the Figure 4 SEM of the inside of the foamed fluororubber, the area where the small arrow is located in the figure is a part of the microchannel. The overall arrangement of the microchannels is relatively uniform, and the direction pointed by the arrow can be the flow direction of the lubricating oil. Under high-temperature conditions, the overflowing lubricating oil or grease is inhaled and flows into the storage structure for temporary storage. After the temperature drops, the stored lubricating oil or grease is continuously and slowly output through the microchannels to achieve the lubrication effect.

[0032] The internal storage structure penetrates through the three parts of the foamed fluororubber, the metal skeleton, and the matrix fluororubber.

[0033] Furthermore, the surfaces of the foamed fluororubber and the matrix fluororubber are pressed into a fish-scale-like bionic microstructure through a hot-pressing forming technique, which effectively reduces friction when the bearing roller contacts and works with the seal ring.

[0034] There are micropores in the low-lying areas of the fish-scale-like bionic structure 6.

[0035] Furthermore, the cross-sectional diameter of the storage structure 4 is greater than 1 / 3 of the cross-sectional size of the seal and less than 2 / 3 of the cross-sectional size of the seal; the cross-section of the storage structure 4 is circular.

[0036] As the temperature rises, part of the lubricating oil or grease will oxidize. Its fluidity increases with the temperature. The change in air pressure difference caused by temperature allows the lubricating oil or grease to enter the internal microchannels of the foamed fluororubber. The microchannels can absorb and release the overflowing lubricating oil or grease. The storage structure temporarily stores the lubricating oil or grease. And the rubber surface of the seal has a fish-scale-like bionic structure, which can reduce the impact of friction and wear on the sealing performance.

[0037] Furthermore, the matrix fluororubber 3 comprises the following components in parts by weight: 100 - 120 parts of rubber raw material, 3 - 4 parts of active light magnesium oxide, 5 - 7 parts of calcium hydroxide, 2 - 3 parts of bisphenol AF, 0.5 - 1 part of triphenylphosphine chloride BPP, 30 - 50 parts of N990 carbon black, and 3 - 6 parts of silica.

[0038] Furthermore, the foamed fluororubber 4 comprises the following components in parts by weight: 20 - 30 parts of fluororubber, 40 - 60 parts of molecular sieve, 15 - 30 parts of white carbon black, 4 - 6 parts of CaCO3, 4 - 6 parts of high-density polybutene, 3 - 6 parts of zinc oxide, 1 - 2 parts of stearic acid, 3 - 5 parts of resin C5, 4 - 6 parts of sulfur, 2 - 4 parts of dicumyl peroxide DCP, and 2 - 6 parts of blowing agent, with a total of 100 parts.

[0039] The present invention also provides the following technical solution: A preparation method of a double-lip rubber seal for a microfluidic bionic bearing, comprising the following steps:

[0040] S1. Prepare the matrix fluororubber:

[0041] Raise the temperature of the open mill to 30°C. After kneading the fluororubber raw material for 5 minutes, successively add magnesium oxide, calcium hydroxide, bisphenol AF, BPP, and carbon black, and thin-pass 10 times; then add the silica filler, knead evenly and let stand for 2 hours;

[0042] S2. Prepare the foamed fluororubber:

[0043] Crush and thin-pass the fluororubber on the open mill 5 times, successively add zinc oxide, stearic acid, resin C5, molecular sieve, white carbon black, CaCO3, and high-density polybutene; then add sulfur and dicumyl peroxide DCP and knead evenly, and then add the blowing agent and knead evenly;

[0044] S3. Polish both sides of the metal skeleton until the surface is smooth without obvious unevenness;

[0045] S4. Put the foamed fluororubber, matrix fluororubber, and metal skeleton into a vulcanizer for hot melt bonding, and vulcanize the fluororubber at the same time;

[0046] S5. Trim the vulcanized fluororubber, and then perform secondary vulcanization.

[0047] Furthermore, the kneading temperature in step S2 is 25 - 35°C; in the vulcanization of step S4, the vulcanization temperature is 175 - 180°C, the time is 8 - 12 min, and the vulcanization pressure is 50 - 75 MPa.

[0048] Furthermore, in step S5, the temperature of the secondary vulcanization is 225 - 235°C, and the vulcanization time is 15 - 20 h.

[0049] Furthermore, in step S2, the kneading sequence for preparing the foamed fluororubber will have a certain impact on the foamed fluororubber. First, most of the relatively difficult-to-knead-uniformly particle fillers are added. Adding them preferentially can improve their uniformity. Secondly, vulcanizing agents, foaming agents, etc. are added. The time intervals for these substances to take effect are relatively short. If they are added too early, vulcanization will occur before the rubber is fully kneaded and foaming holes will appear, which will all affect the quality of the foamed fluororubber.

[0050] Compared with the prior art, the present invention can store and release lubricating oil or grease according to temperature changes during the working process of the seal. When the temperature inside the bearing is relatively high, the microchannels and storage structures inside the seal expand, absorbing the grease and lubricating oil. When the temperature inside the bearing decreases, the microchannels and storage structures inside the seal contract, releasing the grease and lubricating oil to lubricate the bearing. At the same time, the rubber surface in contact with the bearing rollers of the sealing ring has a fish-scale-like bionic structure, which can effectively reduce the friction during contact and improve the wear resistance of the seal.

[0051] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A double-lip rubber seal for a microfluidic bionic bearing, characterized in that, It includes a metal skeleton (1), foamed fluororubber (2), matrix fluororubber (3), and a storage structure (4); the foamed fluororubber is bonded to the upper side of the metal skeleton (1) and has a microchannel structure (5) inside; the matrix fluororubber (3) is bonded to the lower side of the metal skeleton (1); the metal skeleton (1) is wrapped by the mutual bonding of the foamed fluororubber (2) and the matrix fluororubber (3) to jointly form the storage structure (4), and the surfaces of the matrix fluororubber (3) and the foamed fluororubber (2) have a fish-scale-like bionic structure (6), and there are micropores at the depressions of the fish-scale-like bionic structure (6); the microchannel structure (5) is micron-sized, criss-crossed, interconnected, and communicates with the storage structure (4).

2. The microfluidic bionic bearing double-lip rubber seal according to claim 1, characterized in that: The cross-section of the microchannel structure (5) is in the shape of an irregular hole, and the microchannel structures are criss-crossed inside the foamed fluororubber (2).

3. The double-lip rubber seal of the microfluidic bionic bearing according to claim 1, characterized in that: The cross-sectional diameter of the storage structure (4) is greater than 1 / 3 of the cross-sectional size of the seal and less than 2 / 3 of the cross-sectional size of the seal; the cross-section of the storage structure (4) is circular.

4. The microfluidic bionic bearing double-lip rubber seal according to claim 1, characterized in that: The matrix fluororubber (3) includes the following components in parts by weight: 100 - 120 parts of rubber raw material, 3 - 4 parts of active light magnesium oxide, 5 - 7 parts of calcium hydroxide, 2 - 3 parts of bisphenol AF, 0.5 - 1 part of triphenylphosphine chloride BPP, 30 - 50 parts of N990 carbon black, and 3 - 6 parts of silica.

5. The lip rubber seal of the microfluidic bionic bearing according to claim 1, characterized in that: The foamed fluororubber comprises the following components in parts by weight: 20 - 30 parts of fluororubber, 40 - 60 parts of molecular sieve, 15 - 30 parts of white carbon black, CaCO3 4~6 parts, 4 - 6 parts of high-density polybutene, 3 - 6 parts of zinc oxide, 1 - 2 parts of stearic acid, 3 - 5 parts of resin C5, 4 - 6 parts of sulfur, 2 - 4 parts of dicumyl peroxide DCP, 2 - 6 parts of blowing agent, with a total of 100 parts.

6. A preparation method of the double-lip rubber seal for the microfluidic bionic bearing according to any one of claims 1 to 5, characterized in that: It includes the following steps: S1. Prepare the matrix fluororubber: Raise the temperature of the open mill to 30 °C, knead the fluororubber raw material for 5 min, then add magnesium oxide, calcium hydroxide, bisphenol AF, BPP, and carbon black in sequence, and thin-pass 10 times; then add the silica filler, knead evenly and let stand for 2 h; S2. Prepare the foamed fluororubber: Break the fluororubber on an open mill and thin it out 5 times. Add zinc oxide, stearic acid, resin C5, molecular sieve, silica white, CaCO3 , high-density polybutene in sequence; then add sulfur and dicumyl peroxide (DCP) and mix evenly, and then add the blowing agent and mix evenly; S3. Grind both sides of the metal skeleton until the surface is smooth without obvious unevenness; S4. Put the foamed fluororubber, matrix fluororubber, and metal skeleton into a vulcanizer for hot melt bonding, and vulcanize the fluororubber at the same time; S5. Trim the vulcanized fluororubber, and then carry out secondary vulcanization.

7. The preparation method of the double-lip rubber seal of the microfluidic bionic bearing according to claim 6, characterized in that: The kneading temperature in step S2 is 25 - 35 °C; in the vulcanization of step S4, the vulcanization temperature is 175 - 180 °C, the time is 8 - 12 min, and the vulcanization pressure is 50 - 75 MPa.

8. The preparation method of the double-lip rubber seal of the microfluidic bionic bearing according to claim 6, characterized in that: In step S5, the temperature of the secondary vulcanization is 225 - 235 °C, and the vulcanization time is 15 - 20 h.

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