A cast-type polyurethane bearing and its preparation method

Abstract

This invention belongs to the field of manufacturing technology for seismic isolation polyurethane bearings, specifically a cast-type polyurethane bearing, comprising a bearing body, an upper connecting plate and a lower connecting plate, and multiple layers of stiffening plates disposed between the upper and lower connecting plates. The stiffening plates are vertically provided with a plurality of air vents. The upper connecting plate, lower connecting plate, and stiffening plates are fixed together by a polyurethane elastomer. By adding air vents and positioning holes, the risks of air bubbles and misalignment are effectively avoided. Simultaneously, the addition of heat-conducting rods inside the bearing body promotes uniformity during vulcanization, improving product quality, ensuring product performance uniformity, and contributing to a higher yield rate for polyurethane bearing molding.

Description

Technical Field

[0001] This invention belongs to the field of manufacturing technology of seismic isolation polyurethane bearing products, and specifically relates to a cast-type polyurethane bearing and its preparation method. Background Technology

[0002] Polyurethane bearings are a new type of seismic isolation and damping product. They have stronger aging resistance, corrosion resistance, hydrolysis resistance, and high load-bearing capacity than rubber. Polyurethane bearing products need to undergo trial production and verification to meet different design requirements. Based on the verification results, the product structure is adjusted. Therefore, the molding process of polyurethane bearings needs to be stable, adjustable, and easy to operate.

[0003] Current cast polyurethane bearings employ a layered structure design, ensuring both ultimate shear performance and superior vertical load-bearing capacity. There are two existing polyurethane molding processes: one uses a vertical casting mold to fix the stiffening plates, with casting done along the gaps between them. However, this method requires high mold precision and tight fit, and the number and thickness of the stiffening plates are relatively fixed, resulting in higher mold costs. The second method involves stacking the stiffening plates at the edges using positioning blocks, and then casting from the bottom using a polyurethane casting machine. However, the casting process for large-size polyurethane bearings is time-consuming, and air between the stiffening plates is difficult to expel during casting. Furthermore, for relatively large products, there is a temperature difference between the mold edge and the center of the stiffening plates, leading to risks of incomplete vulcanization and cracking.

[0004] CN201620462450.7 discloses a polyurethane laminated seismic isolation bearing for bridges, introducing a method for on-site installation of the polyurethane bearing. It briefly describes the structure of the polyurethane bearing, noting that the stiffening plate and polyurethane rubber are cast together, resulting in a simple processing technology and superior performance. The bridge bearing is positioned using an inlay method, avoiding the problem of bolt misalignment between the bearing and the beam / pier, thus improving construction efficiency. Using polyurethane elastomer as the bearing body improves the bearing's resistance to low temperatures, ultraviolet radiation, aging, and corrosion, extending its service life. However, this patent does not avoid the problems of long casting time and difficulty in expelling air between the stiffening plates during the casting process.

[0005] CN201620904597.7 discloses a polyurethane rubber plate bearing production line, mainly comprising a fully automatic vacuum batching machine, a rubber material inspection machine, a fully automatic injection machine, and a mold casting unit. The mold includes a rectangular cavity, with symmetrical prepolymer positioning blocks arranged on both sides of the rectangular cavity. Each prepolymer positioning block is a rectangle with several grooves arranged longitudinally. Stiffening steel plates are arranged in the symmetrical grooves of the prepolymer positioning blocks on both sides. Resistance wires are arranged around the perimeter of the rectangular cavity. However, this method does not solve the problem of uneven heating of the polyurethane bearing near the mold edge and the center of the stiffening plate, which can easily lead to misalignment of the stiffening plate.

[0006] Therefore, there is a need to invent a polyurethane support product that can avoid the risks of bubbles and misalignment, promote uniformity during the vulcanization process, improve product quality, and ensure the uniformity of product performance. Summary of the Invention

[0007] To address the shortcomings of the existing technology, this invention discloses a castable polyurethane support. By adding air vents and positioning holes, the risks of air bubbles and misalignment are effectively avoided. At the same time, a heat-conducting rod is added inside the support body to promote uniformity during vulcanization, thereby improving product quality, ensuring product performance uniformity, and helping to increase the molding qualification rate of polyurethane support products.

[0008] The method for preparing the cast-type polyurethane bearing of the present invention obtains a polyurethane bearing with uniform structure and qualified performance through a low-cost mold.

[0009] To address the above problems, the technical solution proposed by this invention is as follows:

[0010] A castable polyurethane bearing is disclosed, comprising a bearing body, an upper connecting plate and a lower connecting plate, and a multi-layer stiffening plate disposed between the upper connecting plate and the lower connecting plate. The stiffening plate is provided with a plurality of air guide holes in the vertical direction. The upper connecting plate, the lower connecting plate and the stiffening plate are fixed together by a polyurethane elastomer.

[0011] The castable polyurethane support of this invention achieves air venting during polyurethane casting by vertically setting air guide holes in the stiffening plate. This shortens the air venting time and avoids air trapping. It fundamentally solves the problem of air being difficult to expel between the stiffening plates during the casting process.

[0012] Furthermore, the upper connecting plate, stiffening plate, and lower connecting plate are all circular plates, and the opening parameters of the air guide hole conform to the following relationship with the thickness of the polyurethane elastomer: Where S1: first shape factor, d: product diameter, d0: equivalent diameter of opening, tr: thickness of single-layer polyurethane elastomer.

[0013] Furthermore, the distribution of the air guide holes is set according to the vertical compressive stiffness of the entire support. Kv: Vertical compressive stiffness, A: Effective cross-sectional area (4πd) 2 -4πd0 2 ), t r : Thickness of a single layer of polyurethane elastomer, Ec: compressive elastic modulus, n is the number of layers of polyurethane elastomer.

[0014] This invention comprehensively considers the performance of the air vents and the entire bearing body from a principle perspective, and creatively proposes the relationship between the opening parameters of the air vents and the thickness of the polyurethane elastomer. It also discloses the theoretical basis for setting the distribution of the air vents according to the vertical compressive stiffness of the entire bearing, thus filling a technological gap in the field of seismic isolation polyurethane bearing product manufacturing.

[0015] Furthermore, the air guide holes are distributed in the middle of the stiffening plate, forming a ring shape outward from the center of the support body. Preferably, there are 5-8 air guide holes in the middle of the stiffening plate, with a diameter of Φ10-50mm.

[0016] Furthermore, the upper and lower connecting plates are provided with positioning holes, which are divided into two areas: positioning hole one, located on the outer edge of the support body, is used for positioning; positioning hole two, located near the center of the support body, is used to insert a heat-conducting rod. Adding a heat-conducting rod in the middle of the hollow space enhances heat transfer in the middle of the stiffening plate, while also serving a positioning function. The increased heat transfer effect through the heat-conducting rod shortens the polyurethane gelation time, avoids the risk of misalignment of the stiffening plate, and improves production efficiency. Moreover, it fundamentally solves the problem of temperature differences between the mold edge and the center of the stiffening plate in relatively large products, which could lead to incomplete vulcanization and cracking.

[0017] Furthermore, an annular positioning block is provided between the heat-conducting rod and the stiffening plate to prevent the stiffening plate from bending and causing shear failure. Existing positioning blocks are prone to sliding, resulting in uneven distribution of the iron parts. In this invention, the positioning block is made into an annular shape and passes through the heat-conducting rod for fixation. The fixed position of the positioning block helps to ensure even distribution of the stiffening plate and uniform stress, preventing shear failure caused by bending of the stiffening plate.

[0018] Another object of the present invention is to disclose a method for preparing the above-mentioned cast polyurethane bearing, comprising the following steps:

[0019] S1. Pre-treatment process: The upper connecting plate, stiffening plate, and lower connecting plate are sandblasted, leveled, cleaned, and sprayed with adhesive to improve the adhesion between the adhesive and the stiffening plate; the bonding effect is controlled through strict pre-treatment process of the connecting plate and stiffening plate.

[0020] S2. Mold treatment: Clean the mold, spray the internal cavity with release agent, place the lower mold, put in the rubber sealing ring, put the lower connecting plate into the bottom mold, insert the heat conducting rod into the positioning hole 2 of the lower connecting plate, put the positioning block on the heat conducting rod, add a layer of stiffening plate, repeat the above actions, confirm that there are N layers of stiffening plate and N+1 layers of positioning block, put in the upper connecting plate, put on the middle mold, and put the whole into the oven to preheat at 100±20℃ for 1-3 hours;

[0021] S3. Material preparation: Place polyurethane components A and B into an oven for preheating. Weigh and mix the preheated components according to a certain mass ratio and disperse them. Preheat at 80-100℃ for 4-5 hours.

[0022] S4. Pouring: Tilt the mold, insert the polyurethane pouring head into the lower connecting plate, and pour the polyurethane raw material to be flush with the upper connecting plate. When pouring, pay attention to the air vents of each stiffening plate. When the polyurethane overflows the stiffening plate, no more air bubbles will emerge from the air vents.

[0023] S5. Vulcanization: Control the gelation time to 20±10min, then close the mold. When closing the mold, control the machine stroke rate to 50-60mm / min and close the mold slowly to ensure that the polyurethane is compressed and compacted, so as to ensure that the cavity is filled and all air bubbles are squeezed out, and then vulcanize.

[0024] S6. Curing: After vulcanization, the product is removed from the mold and placed in an oven for post-curing at a temperature of 80℃-100℃ for 20-30 hours.

[0025] Further, in step S1, the parameters of the sandblasting are: 30±10min, roughness Ra=4.5±3.5, flatness of the leveling is 1.0±0.8mm, and after cleaning, the thickness of the adhesive sprayed on the upper connecting plate, stiffening plate, and lower connecting plate is controlled at 25±20μm.

[0026] Furthermore, in step S3, the polyurethane A / B composition is in the mass ratio A:B = 1:1-10:1.

[0027] Furthermore, in step S5, the vulcanization temperature is 90±30℃, the vulcanization time is 90±30min, and the vulcanization pressure is 7±3MPa.

[0028] The advantages of this invention compared to the prior art are:

[0029] The castable polyurethane support of the present invention effectively avoids the risks of air bubbles and misalignment by adding air guide holes and positioning holes; at the same time, the addition of heat-conducting rods inside the support body promotes uniformity during the vulcanization process, improves product quality, ensures product performance uniformity, and helps to improve the molding qualification rate of polyurethane support products.

[0030] This invention comprehensively considers the performance of the air vents and the entire bearing body from a principle perspective, and creatively proposes the relationship between the opening parameters of the air vents and the thickness of the polyurethane elastomer. It also discloses the theoretical basis for setting the distribution of the air vents according to the vertical compressive stiffness of the entire bearing, thus filling a technological gap in the field of seismic isolation polyurethane bearing product manufacturing.

[0031] The preparation method of the cast-type polyurethane bearing of this invention fully considers the structural characteristics of the entire bearing body and adopts a strict pretreatment process for the stiffening plate. Through sandblasting, leveling, cleaning, and adhesive spraying, the adhesion between the adhesive and the stiffening plate is improved. During the vulcanization process, attention should be paid to the vulcanization time, temperature, and pressure. The vulcanization pressure should not be too high, as this can easily cause the product to crack during vulcanization. The addition of heat-conducting rods can enhance the heat transfer effect, ensuring uniform heating inside and outside the polyurethane bearing, resulting in a uniform distribution of vulcanization degree and avoiding over-vulcanization or under-vulcanization. During testing, the polyurethane will not peel off from the stiffening plate, causing tearing of the polyurethane bearing.

[0032] In summary, this invention achieves a polyurethane support with uniform structure and qualified performance through low-cost molds. Strict pretreatment processes for connecting plates and stiffening plates control the bonding effect, while attention is paid to casting details. Adding air vents and positioning holes avoids the risk of air bubbles and misalignment. Adding heat-conducting rods promotes uniformity during vulcanization, thus improving product quality, ensuring product performance uniformity, and ultimately increasing the yield rate of polyurethane support molding. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the cast polyurethane support described in Embodiment 1 of the present invention.

[0034] Figure 2 This is a top view schematic diagram of the cast polyurethane support described in Embodiment 1 of the present invention.

[0035] Figure 3 This is a flowchart of the preparation method of the cast polyurethane support described in Embodiment 2 of the present invention.

[0036] In the diagram: 1-Upper connecting plate, 2-Reinforcing plate, 3-Lower connecting plate, 4-Polyurethane elastomer, 5-Air vent, 6-Positioning hole one, 6'-Positioning block, 7-Positioning hole two, 7'-Heat conduction rod, 8-Through-type sandblasting machine, 9-Leveling machine, 10-Cleaning line, 11-Glue spraying line, 12-Polyurethane A / B raw materials, 13-Preheating oven, 14-Weighing electronic scale, 15-Dispersion device, 16-Mold, 17-Vulcanizing machine, 18-Post-process production line. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings. The drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Example 1

[0038] like Figures 1-2 As shown, the cast polyurethane support of this embodiment includes a support body, including an upper connecting plate 1 and a lower connecting plate 3, and a multi-layer stiffening plate 2 disposed between the upper connecting plate 1 and the lower connecting plate 3. The stiffening plate 2 is provided with a plurality of air guide holes 5 in the vertical direction. The air guide holes 5 are distributed in the middle position of the stiffening plate 2 and are arranged in a ring shape outward from the center of the support body.

[0039] The upper connecting plate 1, the lower connecting plate 3, and the stiffening plate 2 are fixed together by a polyurethane elastomer 4. During polyurethane casting, the through hole in the middle of the stiffening plate 2 serves as a venting mechanism, shortening the venting time and preventing air trapped.

[0040] In this embodiment, the upper connecting plate 1, the stiffening plate 2, and the lower connecting plate 3 are all circular plates. The opening parameters of the air vent 5 and the thickness of the single-layer polyurethane elastomer conform to the following relationship: Where S1: first shape factor, d: product diameter, d0: equivalent diameter of opening, tr: thickness of single-layer polyurethane elastomer.

[0041] The distribution of the air guide holes 5 is set according to the vertical compressive stiffness of the entire support. Kv: Vertical compressive stiffness, A: Effective cross-sectional area (4πd) 2 -4πd0 2 ), t r : Thickness of a single layer of polyurethane elastomer, Ec: compressive elastic modulus, n: number of polyurethane elastomer layers. The aforementioned company in this embodiment proposed the relationship between the opening parameters of the air vent 5 and the thickness of the polyurethane elastomer, and disclosed the theoretical basis for setting the distribution of the air vent 5 according to the vertical compressive stiffness of the entire support; filling a technological gap in the field of seismic isolation polyurethane bearing product manufacturing.

[0042] In this embodiment, the upper connecting plate 1 and the lower connecting plate 3 are provided with positioning holes. The positioning holes are divided into two areas: positioning hole 6, located on the outer edge of the support body, is used for positioning; positioning hole 7, located near the center of the support body, is used to insert the heat-conducting rod 7'. Adding the heat-conducting rod 7' in the middle empty space enhances heat transfer in the middle of the stiffening plate, while also serving a positioning function. The heat-conducting rod increases the heat transfer effect, shortens the polyurethane gelation time, avoids the risk of misalignment of the stiffening plate, and improves production efficiency. This fundamentally solves the problem of temperature differences between the mold edge and the center of the stiffening plate for relatively large products, which could lead to incomplete vulcanization and cracking.

[0043] Meanwhile, an annular positioning block 6' is provided between the heat-conducting rod 7' and the stiffening plate 2 to prevent the stiffening plate 2 from bending and causing shearing damage. This solves the problem of existing positioning blocks easily sliding, leading to uneven distribution of iron parts. The positioning block 6' is made into a ring and passes through the heat-conducting rod 7' for fixation. The positioning block is fixed in position, the stiffening plate is evenly distributed, the force is even, and the bending of the stiffening plate is prevented from causing shearing damage. In this embodiment, it is preferable to open a ring of 5-8 through holes with a diameter of Φ10-50mm in the middle of the stiffening plate 2. Three heat-conducting rods 7' are added in the middle empty space to enhance the heat transfer in the middle of the stiffening plate 2. At the same time, the heat-conducting rods 7' can also serve a positioning function. The heat-conducting rods 7' increase the heat transfer effect, shorten the polyurethane gel time, avoid the risk of misalignment of the stiffening plate, and improve production efficiency. Example 2

[0044] like Figure 3 As shown, the equipment for preparing the cast polyurethane support in this embodiment includes a through-type sandblasting machine 8, a leveling machine 9, a cleaning line 10, a glue spraying line 11, polyurethane A / B raw materials 12, a preheating oven 13, a weighing electronic scale 14, a dispersing device 15, a mold 16, a vulcanizing machine 17, and a post-processing production line 18.

[0045] The preparation method of the cast polyurethane bearing includes the following steps:

[0046] Clean the mold 16, put the rubber sealing ring on the bottom mold, place the upper and lower connecting plates, and place the heat conduction rod 7' in the positioning hole 7 of the connecting plate;

[0047] After the stiffening plate 2 is pre-treated, a layer of stiffening plate 2 is laid, and a layer of positioning block 6' is placed on the heat conduction rod 7'. The number of layers of stiffening plate 2 is confirmed to ensure the product height.

[0048] After mixing the polyurethane raw materials in a certain proportion, tilt the mold and insert the polyurethane pouring head into the lower connecting plate 3. Quickly pour the polyurethane raw materials to the level of the upper connecting plate 1. When pouring, pay attention to the through holes of each layer of stiffening plate 2. When the polyurethane overflows the stiffening plate 2, no more air bubbles will emerge from the through holes.

[0049] After the polyurethane is poured, no bubbles emerge and the polyurethane does not gel. The tilted mold is then straightened, and the heat-conducting rod ensures that the polyurethane temperature is evenly distributed. The temperature difference between the mold edge and the center of the stiffening plate is not significant. Wait for the gel point to close the mold.

[0050] After the polyurethane gel is applied, the upper mold is closed and the mold is slowly closed on the vulcanizing machine to ensure that the polyurethane is compressed and compacted. When closing the mold, excess polyurethane should be seen overflowing to ensure that the cavity is filled and all air bubbles are squeezed out.

[0051] During the vulcanization process, attention should be paid to the vulcanization time, temperature, and pressure. The vulcanization pressure should not be too high, otherwise the product may crack during vulcanization. Adding heat-conducting rods can enhance the heat transfer effect, ensure uniform heating inside and outside the polyurethane support, and make the vulcanization degree of the product evenly distributed, avoiding over-vulcanization and under-vulcanization.

[0052] according to Figure 1 The structural design drawing of the polyurethane support product shown has an outer diameter of φ520mm, a height of 186mm, an outer diameter of φ500mm for the upper connecting plate in sequence 1, an outer diameter of φ500mm for the lower connecting plate in sequence 3, an outer diameter of φ500mm for the stiffening plate in sequence 2, and 12 layers of stiffening plates. Therefore, there are 13 layers of polyurethane in sequence 4, with a single layer of film thickness of 6mm.

[0053] The specific method for preparing the cast-in-place polyurethane bearing includes the following steps:

[0054] S1. Pre-treatment process: The upper connecting plate 1, stiffening plate 2, and lower connecting plate 3 are sandblasted, leveled, cleaned, and glued to improve the adhesion between the adhesive and the stiffening plate. First, the upper connecting plate 1, stiffening plate 2, and lower connecting plate 3 are sandblasted for 30±10 minutes using a sandblasting machine 8 to achieve a roughness of Ra=4.5±3.5. The sandblasted iron parts are then moved to the next process 9 for leveling, with a flatness of 1.0±0.8. The stiffening plate 2 and the upper and lower connecting plates are then placed on the cleaning line 10 for air gun cleaning. After cleaning, the connecting plate 2 and the upper and lower stiffening plates are uniformly glued on the glue spraying line 11, with the glue thickness controlled at 25±20μm. The process from sandblasting to glue spraying should be controlled within 4 hours.

[0055] S2. Mold processing: Clean the mold 16, spray the internal cavity with release agent, place the lower mold, put in the rubber sealing ring, put the lower connecting plate 3 into the bottom mold, insert the heat conducting rod into the positioning hole 7 of the lower connecting plate 3, put the positioning block 6' on the heat conducting rod 7', add a layer of stiffening plate 2, repeat the above actions, confirm that there are N layers of stiffening plate and N+1 layers of positioning block. In this embodiment, there are 12 layers of stiffening plate and 13 layers of positioning block; put in the upper connecting plate 1, put on the middle mold, and put the whole into the oven to preheat at 100±20℃ for 1-3 hours;

[0056] S3. Material Preparation: Preheat polyurethane components A and B separately in an oven at 80-100℃ for 4-5 hours. In this embodiment, preheating is carried out at 90℃ for 4 hours. Weigh and mix the preheated components according to a certain mass ratio and disperse them. Place polyurethane components A and B separately in oven 13 for preheating. Weigh and mix the preheated components according to a certain mass ratio using an electronic scale 14 (the formula is A:B = 1:1-10:1). Disperse the polyurethane mixture in a dispersion device 15. The dispersion can be carried out using a casting machine or a vacuum mixer.

[0057] S4. Pouring: Tilt the mold, insert the polyurethane pouring head into the lower connecting plate 3, and pour the polyurethane raw material to be flush with the upper connecting plate 1. When pouring, pay attention to the air vents 5 of each layer of stiffening plate 2. When the polyurethane overflows the stiffening plate 2, no more air bubbles will emerge from the air vents 5.

[0058] S5. Vulcanization: Control the gelation time to 20±10min, then close the mold. During mold closing, control the machine stroke rate to 50-60mm / min. Close the mold to ensure that the polyurethane is compressed and compacted, so as to ensure that the cavity is filled and all air bubbles are squeezed out. Then vulcanize in vulcanizing machine 17. The vulcanization temperature is 90±30℃, the vulcanization time is 90±30min, and the vulcanization pressure is 7±3MPa. In this embodiment, the preferred vulcanization temperature is 100℃, the vulcanization time is 120min, and the vulcanization pressure is 10MPa.

[0059] S6. Curing: After vulcanization, the product is demolded and placed in an oven for post-curing. After demolding, the product goes through the post-processing step 18 of the subsequent production line and is placed in an oven for post-curing at 90℃ for 24 hours. The product is then complete.

[0060] The casting-type polyurethane support molding process of this invention obtains polyurethane supports with uniform structure and qualified performance through low-cost molds. Strict pretreatment processes for connecting plates and stiffening plates control the bonding effect, while paying attention to casting details. The addition of air vents and positioning holes avoids the risks of air bubbles and misalignment, and the addition of heat-conducting rods promotes uniformity during vulcanization, thus improving product quality and ensuring product performance uniformity, which is beneficial to increasing the yield rate of polyurethane support products. The above are merely embodiments of this invention, and the invention is not limited to the fields covered by these embodiments. Commonly known structures and characteristics in the solutions are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the scope of this invention, and these should also be considered within the scope of protection of this invention. These modifications and improvements will not affect the effectiveness of the invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A cast-in-place polyurethane bearing, comprising a bearing body, characterized in that, It includes an upper connecting plate (1) and a lower connecting plate (3), and a multi-layer stiffening plate (2) disposed between the upper connecting plate (1) and the lower connecting plate (3). The stiffening plate (2) is provided with a plurality of air guide holes (5) in the vertical direction. The upper connecting plate (1), the lower connecting plate (3) and the stiffening plate (2) are fixed together by a polyurethane elastomer (4). The upper connecting plate (1), stiffening plate (2), and lower connecting plate (3) are all circular plates. The opening parameters of the air guide hole (5) and the thickness of the single-layer polyurethane elastomer conform to the following relationship: Where, S1: first shape factor, d: product diameter, d0: equivalent diameter of opening, tr: thickness of single-layer polyurethane elastomer; The distribution of the air guide holes (5) is set according to the vertical compressive stiffness of the entire support. Kv: Vertical compressive stiffness, A: Effective cross-sectional area (4πd) 2 -4πd0 2 ), t r : Thickness of a single layer of polyurethane elastomer, Ec: compressive elastic modulus, n: number of layers of polyurethane elastomer; The upper connecting plate (1) and the lower connecting plate (3) are provided with positioning holes. The positioning holes are divided into two areas. Positioning hole one (6) is located on the outer edge of the support body and is used for positioning. Positioning hole two (7) is located near the center of the support body and is used for inserting heat-conducting rods (7').

2. The cast-in-place polyurethane bearing according to claim 1, characterized in that, The air guide hole (5) is located in the middle of the stiffening plate (2) and is arranged in a ring shape outward from the center of the support body.

3. The cast-in-place polyurethane bearing according to claim 1, characterized in that, A ring-shaped positioning block (6') is provided between the heat-conducting rod (7') and the stiffening plate (2) to prevent the stiffening plate (2) from bending and causing shear damage.

4. A method for preparing a cast-type polyurethane bearing according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Pre-treatment process: The upper connecting plate (1), stiffening plate (2), and lower connecting plate (3) are sandblasted, leveled, cleaned, and sprayed with adhesive to improve the adhesion between the adhesive and the stiffening plate; S2. Mold processing: Clean the mold (16), spray the mold release agent into the internal cavity, place the lower mold, put the rubber sealing ring, put the lower connecting plate (3) into the bottom mold, insert the heat conduction rod into the positioning hole 2 (7) of the lower connecting plate (3), put the positioning block (6') on the heat conduction rod, add a layer of stiffening plate (2), repeat the above actions, confirm that the stiffening plate is N layers and the positioning block is N+1 layers, put in the upper connecting plate (1), put on the middle mold, put the whole into the oven at 100±20℃ for 1-3h; S3. Material preparation: Place polyurethane components A and B into an oven for preheating, weigh and mix the preheated components according to a certain mass ratio, and then disperse them. S4. Pouring: Tilt the mold and insert the polyurethane pouring head into the lower connecting plate (3). Pour the polyurethane raw material to the level of the upper connecting plate (1). When pouring, pay attention to the air guide hole (5) of each layer of stiffening plate (2). When the polyurethane overflows the stiffening plate (2), no more air bubbles will emerge from the air guide hole (5). S5. Vulcanization: Control the gelation time to 20±10min, then close the mold. When closing the mold, control the machine stroke rate to 50-60mm / min. Close the mold to ensure that the polyurethane is compressed and compacted, so as to ensure that the cavity is filled and all air bubbles are squeezed out. Then vulcanize. S6. Curing: After vulcanization, the product is removed from the mold and placed in an oven for post-curing.

5. The method for preparing the cast-in-place polyurethane bearing according to claim 4, characterized in that, In step S1, the parameters of the sandblasting are: 30±10min, roughness Ra=4.5±3.5, flatness of the leveling is 1.0±0.8mm, and after cleaning, the thickness of the adhesive sprayed on the upper connecting plate (1), stiffening plate (2), and lower connecting plate (3) is controlled to be 25±20μm.

6. The method for preparing the cast-in-place polyurethane bearing according to claim 4, characterized in that, In step S3, the polyurethane A / B composition is in the mass ratio A:B = 1:1-10:

1.

7. The method for preparing the cast-in-place polyurethane bearing according to claim 4, characterized in that, In step S5, the vulcanization temperature is 90±30℃, the vulcanization time is 90±30min, and the vulcanization pressure is 7±3MPa.

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