Permanent magnet water-lubricated bearing with double eccentric cylinder composite bearing bush in staggered structure

Abstract

The application discloses a kind of permanent magnet water-lubricated bearings with double eccentric cylinder composite bearing bush of staggered structure, including bearing shell, permanent magnet unit, bearing end cover and double eccentric cylinder composite bearing bush.The application uses magnetic force support technology on the basis of traditional water-lubricated bearing, permanent magnet unit can provide upward magnetic force and its radian value range ensures that magnetic force direction is upward, reduces the load of water-lubricated bearing on rotating shaft, improves lubrication state, reduces friction and wear of water-lubricated bearing.At the same time, the bearing bush is designed into double eccentric cylinder structure, which can reduce the air gap between permanent magnet block and bearing bush, increase magnetic force, and further reduce the load on water-lubricated bearing.The application adopts double-layer bearing bush with significant difference in material elastic modulus, which meets the needs of water-lubricated bearing wear resistance, vibration and noise reduction, and unbalanced load resistance.The application adopts staggered structure, which can improve the lubrication state between shaft and bearing bush, promote the generation of dynamic pressure lubrication, and thus enhance the fluid dynamic pressure effect.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of water-lubricated bearings, in particular to a kind of permanent magnet water-lubricated bearings with staggered structure double eccentric cylinder composite bearing bush. BACKGROUND

[0002] Water-lubricated bearings are a kind of high-performance bearings that use high molecular materials to replace traditional metal materials as the working interface of transmission components and use natural water to replace mineral oil as the lubricating medium of transmission system. Because of its advantages of resource conservation, environmental friendliness, simple assembly, safety and reliability, it is widely used in many engineering machinery and ship equipment transmission systems. However, water-lubricated bearings often operate under harsh conditions of low speed and heavy load. At the same time, due to the low viscosity of natural water, the water film has low carrying capacity, and it is easy to form boundary or mixed lubrication state. The contact area between the bearing and the shaft increases, the tribological performance deteriorates, the friction and wear intensify, and friction self-excited vibration is easily induced. Therefore, reducing the contact pressure and friction and wear of water-lubricated bearings is very important for improving their service performance and stable operation for a long time.

[0003] Over the years, to solve the above problems, researchers have conducted a large number of studies on the structure design of water-lubricated bearings, the selection of water-lubricated bearing bush materials, and surface texturing to reduce the friction and wear and vibration and noise of water-lubricated bearings and achieve reliable operation of water-lubricated bearings. From the existing patents, the patent entitled "Permanent magnet auxiliary support type water-lubricated bearing and marine transportation equipment" (publication number: CN210461399U) designs a permanent magnet water-lubricated bearing based on magnetic support technology to replace the traditional water-lubricated bearing, which reduces the contact pressure, friction and vibration and wear rate under the same bearing capacity, while the partial contact ensures the lateral stiffness and the stability of the shafting. The patent entitled "High-load polymer-based water-lubricated modified material and its preparation method" (publication number: CN116120566A) selects a high polymer material as the water-lubricated bearing bush material and modifies the material to optimize the tribological performance to reduce the friction coefficient and wear rate. The patent entitled "Bearing bush with functionally graded biomimetic textured surface and water-lubricated bearing" (publication number: CN212297292U) applies surface texturing on the surface of the water-lubricated bearing bush to enhance the dynamic pressure effect and reduce the friction. The patent entitled "Double-layer vibration reduction type tilting pad radial sliding bearing" (publication number: CN213176474U) adopts a double-layer material structure design for the radial sliding bearing to enhance the liquid film bearing stiffness and increase the ability to absorb vibration energy, with excellent vibration reduction and noise reduction characteristics. In the literature entitled "Self-adaptive water-lubricated stern bearing tribology and dynamics performance analysis", Ma Jun et al. proposed a new type of water-lubricated stern bearing structure with self-adaptive performance, mainly composed of a bearing bush, an elastic element and a damping alloy. The self-adaptive structure of the stern bearing can make the bearing evenly loaded, improve the bearing lubrication state, reduce the bearing wear, and improve the bearing operation life and optimize the vibration transmission characteristics. The patent entitled "Water-lubricated stern bearing device with high bearing capacity and vibration reduction" (publication number: CN113404778A) adds a damping structure in the bearing bush to generate a larger damping to form energy dissipation and achieve the purpose of reducing bearing vibration. From the above research and patents, the main measures to design a water-lubricated bearing with low friction and wear, long service life and stable service include: 1) based on magnetic support technology, reduce the stress on the bearing bush; 2) use modified high polymer materials instead of traditional rubber materials to reduce the possibility of friction and vibration; 3) strengthen the dynamic pressure effect through micro-texture to reduce the contact pressure and friction; 4) use elastic elements to reduce the unevenness of axial load and wear caused by shaft bending; 5) increase the damping structure to improve the vibration isolation capacity of the bearing bush material and reduce vibration. The above patents or literature often only improve from a single aspect, and these measures integrated into the permanent magnet water-lubricated bearing face many design challenges. For example, the new type of modified high polymer material designed for water-lubricated bearings has the advantages of low friction and low wear, but such materials often have a higher elastic modulus than traditional rubber bearing bushes by more than one order of magnitude, and the increase in support stiffness leads to poor vibration stability.The patent with the patent name of end face gradually expanding multi-layer composite water lubrication bearing (publication number: CN113202859A) is used to solve this problem, adopts a composite bearing bush structure, the inner surface adopts a polymer material to reduce friction vibration, and the outer structure adopts a rubber layer support to improve the eccentric load and vibration reduction performance of the bearing. However, the concentric multi-layer cylindrical bearing bush design increases the air gap between the permanent magnet structure and the bearing bush, which can reduce the magnetic force and increase the total load of the bearing bush. In addition, the patent with the patent name of a vibration reduction and noise reduction water lubrication bearing (publication number: CN206144989U) adopts a surface texture pit which can lose the dynamic pressure enhancement effect due to surface wear during actual service. Therefore, a new type of permanent magnet water lubrication bearing is needed, which can simultaneously meet the requirements of magnetic force, low friction vibration, low friction wear, high vibration isolation performance and high eccentric load capacity. SUMMARY

[0004] To solve the above problems existing in the prior art, the present application designs a permanent magnet water lubrication bearing with staggered structure double eccentric cylinder composite bearing bush which can realize magnetic force auxiliary support, low friction vibration, low friction wear, high vibration isolation performance and high eccentric load capacity.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows: a permanent magnet water lubrication bearing with staggered structure double eccentric cylinder composite bearing bush, comprising a bearing shell, a permanent magnet unit, a bearing end cover and a double eccentric cylinder composite bearing bush;

[0006] The bearing shell is a cylindrical structure.

[0007] The permanent magnet unit comprises a permanent magnet block and a partition plate, which are alternately installed in the mounting groove on the inner side of the bearing shell in the axial direction.

[0008] The bearing end cover has two, which are respectively fixed at both ends of the bearing shell.

[0009] The double eccentric cylinder composite bearing bush is installed in the bearing shell, and the double eccentric cylinder composite bearing bush is a double-layer eccentric cylinder structure, which is divided into an inner layer bearing bush and an outer layer bearing bush, and the lower parts of the inner layer bearing bush and the outer layer bearing bush are connected by a staggered structure.

[0010] The center of the inner circle of the inner layer bearing bush The center of the inner circle of the outer layer bearing bush The center of the inner circle of the bearing shell From top to bottom, the same vertical line on the same cross section.

[0011] Further, the inner circle radius of the inner layer bearing bush The inner circle radius of the outer layer bearing bush The inner circle radius of the bearing shell Satisfy the following relationship:

[0012]

[0013]

[0014]

[0015]

[0016] In the formula, is the inner layer bearing bush eccentricity, is the outer layer bearing bush eccentricity, c is the minimum thickness of the double eccentric cylinder composite bearing bush.

[0017] Further, the inner layer bearing bush is made of high polymer material or high polymer modified material, the high polymer material including PEEK, ultra-high molecular weight polyethylene, polytetrafluoroethylene, flying dragon, sail dragon, nylon material; the outer layer bearing bush is made of rubber or polyurethane material.

[0018] Further, the staggered structure of the inner layer bearing bush is distributed on the outer surface of the bearing bearing area, and the inner surface is directly ground against the shaft; the inner surface of the outer layer bearing bush is provided with a staggered structure corresponding to the outer surface of the inner layer bearing bush, and the outer surface is tightly attached to the inner surface of the bearing shell.

[0019] Further, the bearing end cover and the end surface of the bearing shell are fixed by screws.

[0020] Further, the structure of the permanent magnet unit is symmetrical about the vertical center line on the cross section of the bearing shell, and the radian angle α of the permanent magnet unit is in the range of 45-180°.

[0021] Further, the staggered structure is symmetrical about the vertical center line on the cross section of the bearing shell, and the radian angle β of the staggered structure is in the range of 10-45°.

[0022] Further, the staggered structure includes rectangular tooth structure, trapezoidal tooth structure.

[0023] Further, the cross section of the mounting groove on the inner side of the bearing shell is a fan ring shape; the cross section of the magnetic block and the partition plate is a fan ring shape; the size of the mounting groove matches the size of the magnetic block and the partition plate.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] 1. The application uses magnetic support technology on the basis of traditional water-lubricated bearings, the permanent magnet unit can provide upward magnetic force, and the radian value range ensures that the magnetic force direction is upward, reduces the load of the rotating shaft on the water-lubricated bearing, improves the lubrication state, and reduces the friction and wear of the water-lubricated bearing. At the same time, the bushing is designed as a double eccentric cylinder structure, and the thickness of the thinnest part of the bushing is less than 5mm, which can reduce the air gap between the permanent magnet block and the bushing, increase the magnetic force, and further reduce the load on the water-lubricated bearing and the friction and wear of the water-lubricated bearing.

[0026] 2. The application selects a material with excellent wear resistance, corrosion resistance, low friction coefficient and stable chemical properties to make the inner bearing, which provides good mechanical support for the shaft-bearing system, reduces the friction coefficient of the two sliding surfaces of the shaft and the bushing, reduces the possibility of friction vibration, improves wear resistance and service life. At the same time, the material with good deformation ability, elastic behavior and certain damping capacity is selected to make the outer bushing, which can adapt to the changes of the shaft under different working conditions to improve the anti-unbalanced load capacity of the bearing, and at the same time absorb the energy of impact and vibration to achieve the effect of vibration and noise reduction. In summary, the double-layer bushing design with significant difference in material elastic modulus takes into account the requirements of water-lubricated bearing wear resistance, vibration and noise reduction, and anti-unbalanced load

[0027] 3. The outer surface of the inner bushing bearing area is provided with a staggered structure, and the inner surface of the outer bushing is provided with a corresponding staggered structure, and the radian value range of the staggered structure ensures that the staggered structure is in the contact area of the shaft and the bearing. When the shaft is running and the bushing is subjected to load, due to the different material deformation capabilities of the inner and outer bushings and the existence of the staggered structure, the local deformation difference of the surface forms an alternating liquid film gap, which can improve the lubrication state between the shaft and the bushing, promote the generation of dynamic pressure lubrication, and thereby enhance the fluid dynamic pressure effect. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural schematic diagram (axonometric drawing) of the application.

[0029] Figure 2 is an axial cross-sectional schematic diagram of Figure 1 .

[0030] Figure 3 is a radial cross-sectional schematic diagram of Figure 1 .

[0031] Figure 4 is an eccentric size schematic diagram of the double eccentric cylinder composite bushing of the application.

[0032] Figure 5 is a schematic diagram of the double eccentric cylinder composite bushing of the application using a staggered structure.

[0033] Figure 6 is a schematic diagram of the inner bushing part of the application.

[0034] Figure 7 is the schematic diagram of the outer layer bearing shell part staggered structure of the present application.

[0035] In the figure: 1. bearing housing, 2. permanent magnet block, 3. partition, 4. bearing end cover, 5. double eccentric cylinder composite bearing shell, 6. screw, 7. inner layer bearing shell, 8. outer layer bearing shell, 9. staggered structure. DETAILED DESCRIPTION

[0036] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. As shown in the figure, a permanent magnet water lubricated bearing with staggered structure double eccentric cylinder composite bearing shell 5 comprises a bearing housing 1, a permanent magnet unit, a bearing end cover 4 and a double eccentric cylinder composite bearing shell 5. Figures 1-7

[0037] The bearing housing 1 is a cylindrical structure.

[0038] The permanent magnet unit comprises a permanent magnet block 2 and a partition 3, and the permanent magnet block 2 and the partition 3 are alternately installed in the mounting groove on the inner side of the bearing housing 1 along the axial direction.

[0039] The bearing end cover 4 has two, respectively fixed on both ends of the bearing housing 1.

[0040] The double eccentric cylinder composite bearing shell 5 is installed in the bearing housing 1, and the double eccentric cylinder composite bearing shell 5 is a double-layer eccentric cylinder structure, which is divided into an inner layer bearing shell 7 and an outer layer bearing shell 8, and the lower parts of the inner layer bearing shell 7 and the outer layer bearing shell 8 are connected by the staggered structure 9.

[0041] The center of the inner circle of the inner layer bearing shell 7 The center of the inner circle of the outer layer bearing shell 8 The center of the inner circle of the bearing housing 1 From top to bottom, they are located on the same vertical line on the same cross section.

[0042] Further, the inner circle radius of the inner layer bearing shell 7 The inner circle radius of the outer layer bearing shell 8 The inner circle radius of the bearing housing 1 Satisfy the following relationship:

[0043]

[0044]

[0045]

[0046]

[0047] In the formula, is the eccentricity of the inner layer bearing shell 7,​ The outer bearing bush has an eccentricity of 8. c The minimum thickness of the double eccentric cylinder composite bearing 5.

[0048] Furthermore, the inner bearing 7 is made of polymer material or polymer modified material, including PEEK, ultra-high molecular weight polyethylene, polytetrafluoroethylene, nylon, and ferropolymer; the outer bearing 8 is made of rubber or polyurethane material.

[0049] Furthermore, the interlaced structure 9 of the inner bearing bush 7 is distributed on the outer surface of the bearing bearing area, and the inner surface is directly rubbed against the shaft; the inner surface of the outer bearing bush 8 is provided with an interlaced structure 9 corresponding to the outer surface of the inner bearing bush 7, and the outer surface is in close contact with the inner surface of the bearing housing 1.

[0050] Furthermore, the bearing end cap 4 is fixed to the end face of the bearing housing 1 by screws 6.

[0051] Furthermore, the structure of the permanent magnet unit is symmetrical about the vertical centerline on the cross-section of the bearing housing 1, and the radian angle α of the permanent magnet unit ranges from 45 to 180°.

[0052] Furthermore, the staggered structure 9 is symmetrical about the vertical centerline on the cross-section of the bearing housing 1, and the arc angle β of the staggered structure 9 ranges from 10 to 45°.

[0053] Furthermore, the interlaced structure 9 includes a rectangular tooth structure and a trapezoidal tooth structure.

[0054] Furthermore, the cross-section of the mounting groove on the inner side of the bearing housing 1 is fan-shaped; the cross-section of the magnetic block and the partition 3 is fan-shaped; and the size of the mounting groove matches the size of the magnetic block and the partition 3.

[0055] The functions and roles of some structures in this invention are as follows:

[0056] like Figure 3 As shown, the presence of the permanent magnet unit and the guarantee of the range of radian angle values ​​can provide an upward magnetic force, reduce the load of the rotating shaft on the water-lubricated bearing, improve the lubrication condition, and reduce the friction and wear of the water-lubricated bearing.

[0057] like Figure 4 As shown, the dimensions of the double eccentric cylinder composite bearing 5 meet the following requirements. The relationship ensures the double-layer eccentric cylinder structure; satisfies The relationship ensures that the thickness of the thinnest part of the double eccentric cylinder composite bearing 5 is less than a certain value, thereby obtaining sufficient magnetic force; satisfying The formula ensures that the thickness of the inner bearing shell 7 is not less than the thickness of the outer bearing shell 8, thereby enhancing the strength of the water-lubricated bearing. The double eccentric cylinder composite bearing shell 5 is installed inside the bearing housing 1. The design of the double eccentric cylinder structure can reduce the air gap between the permanent magnet unit and the double eccentric cylinder composite bearing shell 5, increase the magnetic force, and thus reduce the load on the water-lubricated bearing, thereby reducing the friction and wear of the water-lubricated bearing.

[0058] like Figures 4-7 As shown, the interlaced structure 9 is a rectangular tooth structure, symmetrical about the vertical centerline of the bearing housing 1. The arc angle β of the interlaced structure 9 ranges from 10° to 45°, ensuring that the interlaced structure 9 is located in the contact area between the shaft and the bearing, i.e., the load-bearing area of ​​the water-lubricated bearing. The interlaced structure 9 of the inner bearing bush 7 is located on the outer surface of the load-bearing area, and the interlaced structure 9 of the outer bearing bush 8 is located on the inner surface corresponding to the interlaced structure 9 of the inner bearing bush 7. The shape, orientation, size, and positional relationships of the interlaced structure 9 shown in the attached figures are only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the interlaced structure must have a specific shape, orientation, and size, and therefore should not be construed as a limitation of the invention.

[0059] like Figures 4-7 As shown, the inner bearing shell 7 and the outer bearing shell 8 are bonded together to form a double eccentric cylindrical composite bearing shell 5. When the shaft-bearing system is in operation, the inner bearing shell 7, through friction with the shaft, can improve the tribological performance of the bearing, reduce friction and wear, and increase the bearing life. The outer bearing shell 8 adapts to changes in the shaft, improves its resistance to eccentric loads, and plays a role in buffering and vibration reduction. At the same time, due to the different material properties of the inner bearing shell 7 and the outer bearing shell 8 and the presence of the staggered structure 9, the differences in local surface deformation form alternating liquid film gaps, which can improve the lubrication state between the shaft and the bearing shell, promote the generation of hydrodynamic lubrication, thereby enhancing the hydrodynamic effect and reducing the friction, wear, vibration, and noise of water-lubricated bearings.

[0060] This invention is not limited to this embodiment. Any equivalent concept or modification within the technical scope disclosed in this invention shall be included within the protection scope of this invention.

Claims

1. A permanent magnet water-lubricated bearing employing a staggered double eccentric cylinder composite bearing bush, characterized in that: It includes a bearing housing (1), a permanent magnet unit, a bearing end cap (4), and a double eccentric cylinder composite bearing bush (5). The bearing housing (1) has a cylindrical structure; The permanent magnet unit includes a permanent magnet block (2) and a partition plate (3). The permanent magnet block (2) and the partition plate (3) are alternately installed in the mounting groove on the upper inner side of the bearing housing (1) along the axial direction. The permanent magnet unit provides an upward magnetic force to reduce the load of the rotating shaft on the water-lubricated bearing. There are two bearing end caps (4), which are fixed to both ends of the bearing housing (1); The double eccentric cylinder composite bearing (5) is installed inside the bearing housing (1). The double eccentric cylinder composite bearing (5) is a double-layer eccentric cylinder structure, divided into an inner bearing (7) and an outer bearing (8). The lower parts of the inner bearing (7) and the outer bearing (8) are connected by an interlocking structure (9). The center of the inner circle of the inner bearing (7) The center of the inner circle of the outer bearing (8) The center of the inner circle of the bearing housing (1) They are located on the same vertical line on the same cross section from top to bottom.

2. The permanent magnet water-lubricated bearing with staggered double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The inner radius of the inner bearing shell (7) The inner radius of the outer bearing shell (8) Inner radius of bearing housing (1) The following relationship must be satisfied: In the formula, The eccentricity of the inner bearing (7) The eccentricity of the outer bearing (8) c The minimum thickness of the double eccentric cylinder composite bearing (5) is given.

3. The permanent magnet water-lubricated bearing with staggered double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The inner bearing (7) is made of polymer material or polymer modified material, and the outer bearing (8) is made of rubber material.

4. A permanent magnet water-lubricated bearing with an interlaced double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The interlaced structure (9) of the inner bearing shell (7) is distributed on the outer surface of the bearing bearing area, and the inner surface is directly rubbed against the shaft; the inner surface of the outer bearing shell (8) is provided with an interlaced structure (9) corresponding to the outer surface of the inner bearing shell (7), and the outer surface is in close contact with the inner surface of the bearing housing (1).

5. A permanent magnet water-lubricated bearing with an interlaced double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The bearing end cap (4) is fixed to the end face of the bearing housing (1) by screws (6).

6. A permanent magnet water-lubricated bearing with an interlaced double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The structure of the permanent magnet unit is symmetrical about the vertical center line on the cross section of the bearing housing (1), and the radian angle α of the permanent magnet unit is in the range of 45-180°.

7. A permanent magnet water-lubricated bearing with an interlaced double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The staggered structure (9) is symmetrical about the vertical center line on the cross section of the bearing housing (1), and the arc angle β of the staggered structure (9) ranges from 10 to 45°.

8. A permanent magnet water-lubricated bearing with an interlaced double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The cross-section of the mounting groove inside the bearing housing (1) is fan-shaped; the cross-section of the permanent magnet block and the partition plate (3) is fan-shaped; the size of the mounting groove matches the size of the permanent magnet block and the partition plate (3).

9. A permanent magnet water-lubricated bearing with an interlaced double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The outer bearing (8) is made of polyurethane material.

10. A permanent magnet water-lubricated bearing with an interlaced double eccentric cylinder composite bearing bush as described in claim 1, characterized in that: The interlaced structure (9) is a rectangular tooth structure.

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