CN105114446A - Changeable stepped damping thrust bearing - Google Patents

Abstract

The invention relates to a changeable stepped damping thrust bearing. The thrust bearing is mainly composed of a pressing head (1), a thrust disc (2), a plurality of movable bush assemblies, a plurality of fixed bushes (4) and a supporting ring (5), wherein the pressing head (1), the thrust disc (2), the movable bush assemblies, the fixed bushes (4) and the supporting ring (5) are arranged from top to bottom. The thrust disc (2) is connected with a rotary shaft of the bearing through the pressing head (1), and the thrust disc (2), the rotary shaft of the bearing and the pressing head are coaxially and fixedly connected. Each movable bush assembly and the corresponding fixed bush (4) are attached together to form a stepped variable-height bearing bush assembly. The multiple bearing bush assemblies are arranged on the supporting ring (5) in the circumferential direction to share the total load in the axial direction. The movable bush assemblies of the bearing bush assemblies are mounted in front of the fixed bushes (4) when seen from the rotating direction of the thrust disc (2). The changeable stepped damping thrust bearing can be used for designing of bearings which often work under variable working conditions, allow inclination of thrust discs and have high requirements for the bearing capacity and the damping performance of naval ships and the like.

Description

Variable step damping thrust bearing

technical field

The invention belongs to the technical field of sliding bearings, and in particular relates to a sliding bearing with a variable step structure and vibration damping effect formed by the cooperation of a fixed thrust pad and a movable thrust pad supported by a damping pad. Variable step damping thrust bearing.

Background technique

The types of sliding bearings currently used in engineering are mainly fixed pad bearings [US Patent US5456535: Journalbearing, patent authorization date: October 10, 1995] and tilting pad bearings [US Patent US5795077: TiltingPadJournalbearing, patent authorization date: 1998 August 18]. The fixed shoe thrust bearings that bear axial force generally include plane multi-groove thrust bearings, oblique-plane thrust bearings and stepped surface thrust bearings. Among them, the common stepped bearing is the Rayleigh stepped bearing designed by Rayleigh in 1918. Through the variational method, he found that the bearing capacity is the highest when the shape of the liquid film is two plane regions. This is the optimally loaded step height chosen to give the bearing the maximum fluid film thickness at a given speed and load. This is applicable to units with particularly stable working conditions, but when the load or speed fluctuates greatly or the working conditions need to be frequently changed, such as ship propulsion systems, the service performance of the bearings cannot be achieved because the step height is a fixed value. to the optimal design value. In the patent document "Variable Structure Adaptive Sliding Bearing" (Chinese Patent No. 99115719.2: Variable Structure Adaptive Sliding Bearing, patent authorization date: December 4, 2002), a variable structure whose step height can change with the load is proposed. The stepped radial bearing adopts the principle of the tilting pad lever to realize the variable height of the step, and there are problems such as wear and fatigue at the fulcrum of the tilting pad. In addition, for applications such as ships that require high vibration and noise, common bearings have poor vibration reduction and vibration isolation effects, because the liquid film damping effect is very limited. This causes the bearing to easily transmit the vibration of the rotating shaft to the base, and even the bearing itself becomes a vibration source. Therefore, it is very necessary to study effective bearing vibration reduction and isolation measures.

In contrast, the present invention proposes a variable step damping thrust bearing supported by a damping pad.

Contents of the invention

The technical problem to be solved by the present invention is to provide a fixed thrust pad and a movable thrust pad supported by a damping pad in order to overcome the shortcomings that the traditional stepped thrust bearing cannot achieve the optimal load capacity under variable working conditions and the vibration damping effect is poor. Combination of variable step damping thrust bearings.

The present invention solves its technical problem and adopts the following technical solutions:

The variable stepped damping thrust bearing provided by the present invention is mainly composed of pressure head, thrust plate, multiple sets of movable tile components, multiple fixed tiles and support rings arranged from top to bottom, wherein: the thrust plate connects with the pressure head through the pressure head. The rotating shaft of the bearing is connected, and the three are fixed together on the same axis; a set of movable tile components and a fixed tile are fitted together to form a set of bearing tile assemblies with variable step heights, and multiple sets of bearing tile assemblies are installed on the support ring in the circumferential direction Together, they bear the total axial load; from the perspective of the rotation direction of the thrust plate, the movable tile assembly of each bearing tile assembly is installed before the fixed tile.

Each set of movable tile components is mainly composed of movable tiles, damping pads, pressure-stop plates and pads, wherein: the movable tiles and the damping pads are fitted together, and they are respectively connected to the inner limit pin and outer limit pin. Constrained on the plane of the support ring; an annular limit groove is set under the outer wall of the movable tile, the pressure stop plate is placed in the annular limit groove, and then fixed on the support ring by fastening screws; pads are arranged between the pressure stop plate and the support ring between.

The outer limit pin and the inner limit pin are installed into the base body of the movable tile and the blind hole of the support ring after passing through the outer hole and the inner hole of the damping pad respectively, wherein: the outer limit pin and the inner limit pin The positioning pin is clearance fit with the blind hole of the base body of the movable tile and the outer hole and inner hole of the damping pad, and is an interference fit with the blind hole on the support ring.

The outer wall of the outer limit pin and the inner limit pin is provided with insulating material to prevent conduction between the movable tile and the support ring.

The outer hole and the inner hole of the damping pad are located on the symmetrical center line of the damping pad, and when assembled, the symmetrical center lines of the damping pad and the movable tile coincide, so that the movable tile mainly moves axially and linearly.

The outer hole and the inner hole of the damping pad are located on the symmetrical centerline of the damping pad. When assembled, the damping pad intersects the symmetrical centerlines of the movable tile, and the angle between the intersection and the wrap angle of the movable tile is equal to The ratio is set at 0.55 to 0.6, so that the movable tile can automatically adjust the inclination angle by utilizing the deformation of the damping pad during operation, forming dynamic pressure lubrication.

The damping pad is made of polymer viscoelastic damping material or intelligent damping material.

The fixed tile is fastened on the support ring with screws.

The above variable step damping thrust bearing provided by the present invention is used for water lubrication or oil lubrication.

The above-mentioned variable stepped damping thrust bearing provided by the present invention has an optimal load-carrying capacity within a range of working conditions, improves the working performance of the bearing under variable working conditions, and is especially suitable for ships and other occasions with high requirements on vibration and noise.

The purpose of the present invention is achieved in that it comprises a thrust plate, a movable shoe assembly, a fixed shoe and a support ring. The movable tile and the fixed tile are combined to form a bearing tile, and the movable tile and the fixed tile are circumferentially fitted to form a bearing step, the fixed tile is fixed on the supporting ring, and the movable tile is supported by an elastic damping pad. After the working condition changes, the damping pad deforms accordingly, resulting in the formation of a step height under the optimal bearing capacity between the movable shoe and the fixed shoe, so as to realize the optimal load bearing of the bearing under changing working conditions; the damping pad can also absorb the vibration transmitted by the rotating shaft energy and the self-excited vibration energy of the movable tiles to achieve the purpose of vibration reduction and vibration isolation; and the deformation of the damping pad is conducive to reducing the difference in load between the tiles and playing the role of load balancing.

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

1. It can adaptively form the step height under the optimal load capacity with the change of working conditions, overcome the limitation of ordinary stepped bearings only in a single working condition, and have the optimal load bearing under variable working conditions, especially suitable for Occasions such as ships that are often in variable working conditions.

2. When there is an angle between the damping pad supporting the movable tile and the symmetric centerline of the movable tile, the movable tile will tilt along with the deformation of the damping pad, thereby forming a wedge-shaped bearing gap with the thrust plate. At the same time, the present invention has the characteristics of the fixed pad thrust bearing and the tilting pad thrust bearing at the same time, and improves the bearing capacity of the bearing and the adaptability to variable working conditions.

3. The damping pad can absorb the vibration energy transmitted by the rotating shaft and the self-excited vibration energy of the movable tile, so as to achieve the purpose of vibration reduction and vibration isolation.

4. The deformation of the damping pad is beneficial to reduce the difference in the load of each tile and play a role of load balancing, thereby improving the problem of deterioration of bearing performance caused by the tilt of the thrust plate.

Description of drawings

Fig. 1 is a schematic diagram of bearing assembly of the present invention.

Fig. 2 is a schematic diagram of the installation of the fixed tile of the present invention.

Fig. 3 is a schematic diagram of installation of the movable tile of the present invention.

Fig. 4 is a schematic diagram of the present invention.

Fig. 5 is a schematic structural view of the first embodiment of the movable tile assembly of the present invention.

Fig. 6 is a schematic structural view of the second embodiment of the movable tile assembly of the present invention.

In the figure: 1. Pressure head; 2. Thrust plate; 3. Movable tile; 4. Fixed tile; 5. Support ring; 6. Outer limit pin hole of movable tile; 7. Outer limit pin; Limiting groove; 9. Fastening screw; 10. Pressure stop plate; 11. Block; 12. Outer limit pin hole of support ring; 13. Surface layer of movable tile; 14. Movable tile base; 15. Movable tile Inner limit pin hole; 16. Inner limit pin; 17. Damping pad; 18. Inner limit pin hole in support ring; 19. Surface layer of fixed tile; 20. Fixed tile base; 21. Positioning threaded hole; 22. Positioning Screw; 23. Countersunk through hole; 24. Inner hole of damping pad; 25. Outer hole of damping pad.

Detailed ways

The present invention will be further described below in conjunction with the embodiments and accompanying drawings, but the present invention is not limited.

A variable stepped damping thrust bearing provided by the present invention has a structure as shown in Fig. 1, which mainly consists of a pressure head 1, a thrust plate 2, multiple sets of movable shoe assemblies, multiple fixed tiles 4 and The supporting ring is composed of 5. Wherein the thrust disc 2 is connected with the rotating shaft through the pressure head 1, and the three are fixedly connected together on the coaxial line. A set of movable tile assemblies and a fixed tile form a set of bearing tile assemblies, and multiple sets of bearing tile assemblies jointly bear the total axial load. Viewed from the direction of rotation of the thrust disc 2, the movable tile assembly of each set of bearing tile assemblies is installed before the fixed tile.

The structure of the set of movable tile assemblies is shown in Figure 2, including movable tiles 3, damping pads 17, outer limit pins 7, inner limit pins 16, fastening screws 9, pressure stop plates 10 and pads 11 . The lower surface of the movable tile base body 14 of the movable tile 3 is provided with two blind holes, which are respectively the movable tile outer limit pin hole 6 and the movable tile inner limit pin hole 15 . The upper surface of the supporting ring 5 is correspondingly provided with two blind holes, which are respectively the outer limit pin hole 12 of the support ring and the inner limit pin hole 18 of the support ring. The outer limit pin 7 and the inner limit pin 16 respectively pass through the outer hole 25 of the damping pad and the inner hole 24 of the damping pad and are installed into the blind holes of the movable shoe base 14 and the support ring 5, wherein the outer limit pin 7 and the inner limit pin 16 are clearance fit with the blind hole of the movable tile base 14 and the through hole of the damping pad 17, and are interference fit with the blind hole on the support ring 5. This structure is to limit the movable shoe 3 and the damping pad 17 in the circumferential and radial directions. The outer walls of the outer limit pin 7 and the inner limit pin 16 are provided with insulating material to prevent conduction between the movable tile and the support ring. In order to prevent the pads from falling when the bearing is installed in the horizontal direction with the axis, the axial movement limit structure of the movable pad 3 is provided, specifically: an annular limit groove 8 is opened under the outer wall of the movable pad 3, and the pressure stop plate 10 is placed on In the annular limit groove 8, it is fixed on the support ring 5 by the fastening screw 9, and a pad 11 is arranged between the pressure stop plate 10 and the support ring 5, and the pad 11 needs to be adjusted according to the axial movement distance of the movable tile 3 11 in height.

As shown in Figure 3, a countersunk through hole 23 is set on the lower surface of the support ring 5, the diameter of which is slightly larger than the diameter of the set screw 22, and a set screw hole 21 is set on the lower surface of the base body 20 of the fixed tile, and the set screw 22 passes through the countersunk hole. The head through hole 23 is screwed into the positioning threaded hole 21 to complete the fixing of the fixed tile 4 .

As shown in FIG. 4 , the movable tile 3 and the fixed tile 4 are circumferentially attached to form a step. After the thrust disc 2 rotates, it drives the lubricating medium into the gap between the tile and the thrust disc, and the lubricating medium first passes through the movable tile 3 and then to the fixed tile 4 . The lubricating liquid film is parallel in the two pad areas, but because there is a step change at the junction of the two pad surfaces, in order to maintain the continuous condition of flow, a pressure distribution must be established in the liquid film to achieve load bearing. Tests have shown that for ordinary stepped bearings with a fixed step height, the conditions for the maximum bearing capacity of ordinary stepped bearings are h ₁ /h ₂ =1.866, B ₁ /B ₂ =2.549. When the load and speed are constant, the liquid film thickness h ₂ remains unchanged, and the step height (h ₁ -h ₂ ) is a definite value; when the load or speed changes, the liquid film thickness h ₂ changes, at this time in order to maintain the ordinary stepped bearing To still have the maximum load capacity, the step height is required to change accordingly, but the step height of ordinary stepped bearings has been fixed when the design and manufacture are completed, so ordinary stepped bearings can only achieve the optimal load of one working point. For this reason, the present invention proposes a variable ladder formed by the combination of the movable tile 3 supported by the damping pad 17 and the fixed tile 4 . The damping pad is deformed after being compressed, which changes the axial position of the movable tile, thereby changing the step height, and the step height is stable when the static force is balanced. After the working condition changes, the pressure on the damping pad changes, and the amount of deformation changes. When the static force is balanced, the step height is at a new stable value. In short, the step height of the structure can be adaptively changed with the working conditions, and it has the optimal bearing capacity in a range of working conditions. In addition, the deformation effect of the damping pad is beneficial to reduce the load difference between the tiles, play a role in load balancing, and improve the ability of the bearing to resist the tilt of the thrust plate.

The above description is for the first embodiment of the present invention, as shown in FIG. 5 . The damping pad inner hole 24 and the damping pad outer hole 25 are located on the symmetrical center line of the damping pad 17 . The basic feature of this embodiment is that the damping pad 17 coincides with the centerline of symmetry of the movable tile 3, that is, the outer limit pin 7 and the inner limit pin 16 are on the centerline of symmetry of the movable tile. In this embodiment, the movable shoe mainly moves axially and linearly.

Referring to FIG. 6 , it is a schematic structural diagram of the second embodiment of the movable shoe assembly of the present invention. The dotted line in the figure is the contour line of the damping pad, and there is an angle α between the damping pad 17 and the symmetrical center line of the movable tile 3, which causes the bearing center of the damping pad 17 to not coincide with the geometric center of the movable tile 3, but exists A circumferential eccentricity which facilitates tilting of the movable tile. At this time, in addition to the dynamic pressure bearing liquid film formed by the stepped structure, the movable tile can automatically adjust the inclination angle by using the deformation of the damping pad during operation to form dynamic pressure lubrication. This embodiment introduces the advantages of the tilting pad bearing on the basis of the stepped bearing, so that the bearing not only has excellent bearing capacity, but also improves stability, and also significantly reduces the height of the ordinary tilting pad thrust bearing. θ is the tile wrap angle, and the eccentricity α/θ is generally 0.55 to 0.6.

As shown in the damping pad 17 in Figure 2, its material can be polymer viscoelastic damping material or intelligent damping material, and the material selection and performance design can be carried out according to the application environment, working conditions and performance requirements, such as for ship bearings exposed to seawater , it needs to have good resistance to seawater corrosion, impact resistance, creep resistance and long service life. The performance design of the damping pad is mainly designed for hardness and strength. The surface layer 19 of the fixed tile and the surface layer 13 of the movable tile should also be selected according to the application. For example, Babbitt metal is commonly used for oil lubrication, and rubber, polymer materials or impregnated graphite can be considered for water lubrication. In addition, the present invention is aimed at thrust sliding bearings, but its design idea of variable steps and damping and vibration reduction can also be used in radial sliding bearings.

The working process of the variable stepped damping thrust bearing provided by the present invention is as follows:

The bearing is immersed in the lubricant, and the rotating shaft drives the thrust plate to rotate. The lubricant is brought into the gap between the thrust plate and the bearing shoe assembly by the thrust plate, and the liquid film pressure is established when the lubricant passes through the steps formed by the movable shoe and the fixed shoe. distribution, forming a liquid film force opposite to the direction of the load; the pressure acting on the movable tile forces the damping pad to deform, the height of the steps changes, the liquid film pressure distribution changes accordingly, and the liquid film force changes; when the liquid film force is equal to the load When the step height and liquid film pressure distribution are determined, the bearing works stably; when the working condition (speed or load) changes, the liquid film pressure changes accordingly, and the step height changes until the liquid film force equal to the load is formed, and the bearing reaches again Stable working condition. When the bearing is working, the vibration of the rotating shaft is transmitted to the bearing pad through the liquid film, and the damping pad on the back of the pad absorbs the vibration energy to achieve the effect of vibration reduction and vibration isolation.

Claims (10)

1. A variable stepped damping thrust bearing, characterized in that the bearing is mainly composed of a pressure head (1), a thrust plate (2), multiple sets of movable tile assemblies, and multiple fixed tiles (4) arranged from top to bottom and a support ring (5), wherein: the thrust plate (2) is connected to the rotating shaft of the bearing through the pressure head (1), and the three are fixedly connected together on the same axis; a set of movable shoe components and a fixed shoe (4 ) to form a set of bearing tile assemblies with variable step heights, multiple sets of bearing tile assemblies are installed on the support ring (5) in the circumferential direction, and jointly bear the total axial load; from the perspective of the rotation direction of the thrust plate (2), each The movable tile assembly of the sleeve bearing tile assembly is installed before the fixed tile (4). 2. The variable stepped damping thrust bearing according to claim 1, characterized in that each set of movable shoe assemblies is mainly composed of movable shoe (3), damping pad (17), pressure stop plate (10) and pad (11 ), wherein: the movable tile (3) fits with the damping pad (17), and they are constrained by the inner limit pin (16) and the outer limit pin (7) connected to the support ring (5) respectively. on the plane; set an annular limit groove (8) under the outer wall of the movable tile (3), the pressure stop plate (10) is placed in the annular limit groove (8), and then fixed on the support ring (5) by fastening screws On; the block (11) is set between the pressure stop plate (10) and the support ring (5). 3. The variable stepped damping thrust bearing according to claim 2, characterized in that the outer limit pin (7) and the inner limit pin (16) pass through the outer hole of the damping pad (17) respectively and the inner hole are installed into the base body of the movable tile (3) and the blind hole of the support ring (5), wherein: the outer limit pin (7) and the inner limit pin (16) are connected with the movable tile (3) The blind hole of the base body and the outer hole and the inner hole of the damping pad (17) are clearance fit, and the blind hole on the support ring (5) is an interference fit. 4. The variable stepped damping thrust bearing according to claim 3, characterized in that the outer wall of the outer limit pin (7) and the inner limit pin (16) are provided with insulating materials to prevent the movable tile from contacting the support. conduction between the rings. 5. The variable stepped damping thrust bearing according to claim 3, characterized in that the outer hole and the inner hole of the damping pad (17) are on the symmetrical center line of the damping pad (17), and the damping pad (17) is assembled (17) coincides with the center line of symmetry of the movable tile (3), so that the movable tile (3) mainly does axial linear motion. 6. The variable stepped damping thrust bearing according to claim 3, characterized in that the outer hole and the inner hole of the damping pad (17) are on the symmetrical center line of the damping pad (17), and the damping pad (17) is assembled (17) intersects with the center line of symmetry of the movable tile (3), and the ratio of the included angle to the wrap angle of the movable tile (3) is 0.55 to 0.6 when intersecting, so that the movable tile (3) is in operation The inclination angle can be automatically adjusted by the deformation of the damping pad to form dynamic pressure lubrication. 7. The variable stepped damping thrust bearing according to claim 2, characterized in that the damping pad (17) is made of polymer viscoelastic damping material or intelligent damping material. 8. The variable stepped damping thrust bearing according to claim 1, characterized in that said fixed shoe (4) is fastened to the supporting ring (5) by screws. 9. Use of the variable stepped damping thrust bearing according to any one of claims 1 to 8, characterized in that the bearing is used in water lubrication or oil lubrication. 10. The use according to claim 9, characterized in that when used in water lubrication or oil lubrication, the bearing has an optimal load-carrying capacity within a range of working conditions, which improves the working performance of the bearing under variable working conditions, and is especially suitable for ships Ships and other occasions that have high requirements for vibration and noise.