A tilting-pad sliding bearing with damping function

Abstract

The application provides a tilting-pad sliding bearing with a damping function and a linkage of bearing pads, which comprises a bearing shell, the bearing shell comprises an upper half shell and a lower half shell which are symmetrically arranged in one body, two upper tilting pads are symmetrically arranged on the inner wall of the upper half shell, two lower tilting pads are symmetrically arranged on the inner wall of the lower half shell, the two upper tilting pads and the two lower tilting pads are elastically connected in one-to-one correspondence, the connecting end of the upper tilting pad and the lower tilting pad which are movably connected on the same side is provided with a movable connecting section, a tension spring for connecting the upper tilting pad and the lower tilting pad is arranged between the two movable connecting sections, and a journal is arranged between the two upper tilting pads and the two lower tilting pads. The non-load-bearing pad and the load-bearing pad are connected through the tension spring, the oil film instability is improved, the vibration amplitude of the bearing pad is reduced, the lubricating performance between the pad and the journal is improved, and the stability of the shaft system is improved.

Description

Technical Field

[0001] This invention relates to the field of bearing design technology, and in particular to a tilting pad sliding bearing with vibration damping function that links the bearing shell. Background Technology

[0002] Tilting pad bearings are crucial components of gas turbines, typically composed of several arc-shaped pads. Each pad can freely swing according to changes in rotor load during operation, forming multiple oil wedges around the shaft diameter. Taking a four-pad tilting pad bearing as an example, factors such as pad mass and installation clearance during gas turbine operation can cause vibration in the upper pad (non-load-bearing pad) and shaft instability, significantly impacting the gas turbine's efficiency.

[0003] Therefore, this application proposes a tilting pad sliding bearing with vibration reduction function that links the bearing pads and non-bearing pads. By connecting the bearing pads and non-bearing pads, the vibration amplitude of the non-bearing pads is reduced, giving them good vibration reduction and load-bearing capacity. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] To achieve the above objectives, this invention proposes a tilting pad sliding bearing with vibration damping function, comprising a bearing housing, the bearing housing comprising an integrally symmetrically arranged upper half housing and a lower half housing, two upper tilting pads symmetrically arranged on the inner wall of the upper half housing, and two lower tilting pads symmetrically arranged on the inner wall of the lower half housing, the two upper tilting pads and the two lower tilting pads being elastically connected in a one-to-one correspondence, the connecting ends of the upper tilting pads and the lower tilting pads on the same side are provided with movable connecting sections, a tension spring for connecting the upper tilting pads and the lower tilting pads is provided between the two movable connecting sections, and a journal is provided between the two upper tilting pads and the two lower tilting pads.

[0006] This invention connects the non-load-bearing bearing pads and the load-bearing bearing pads by setting a movable connecting section, ensuring that the gap between the upper and lower tilting bearing pads is in a suitable position. Structurally, this guarantees that the distance between the upper and lower tilting bearing pads is limited, preventing excessive or insufficient changes in the gap. This improves oil film instability. Furthermore, under the connecting action of the telescopic spring, the connection between the upper and lower tilting bearing pads remains movable, reducing the probability of misalignment due to vibration between the movable connecting sections of the upper and lower tilting bearing pads. Moreover, when the upper and lower tilting bearing pads vibrate, the telescopic spring prevents them from deviating excessively from their normal operating positions, thereby reducing the vibration amplitude of the bearing pads, improving the lubrication performance between the upper and lower tilting bearing pads and the journal, and ultimately enhancing the stability of the shaft system.

[0007] Optionally, the movable connecting sections of the upper tiltable tile connecting end and the lower tiltable tile connecting end respectively provided on the same side include an extension section integrally provided with the corresponding upper tiltable tile or lower tiltable tile. Each extension section is provided with a connecting block facing away from the tiltable tile integrally connected to it. The two connecting blocks are arranged parallel to each other on the sides, and the tension spring is provided between the two connecting blocks on the opposite sides.

[0008] Furthermore, the extension section of the upper tilting tile is located on the side of the upper tilting tile facing the end face of the lower tilting tile, close to the journal, and the extension section of the lower tilting tile is located on the side of the lower tilting tile facing the end face of the upper tilting tile, away from the journal.

[0009] Furthermore, each of the two connecting blocks has a spring cavity with an opening on one side for accommodating a tension spring on its opposite side. The openings of the two spring cavities are directly opposite each other, and the two ends of the tension spring are respectively fixed to the side walls of the two spring cavities with their openings directly opposite each other.

[0010] Furthermore, a pull ring for fixing the tension spring is provided on the side wall of the spring cavity facing the opening.

[0011] Furthermore, several rubber pads are provided between the opposite sides of the two connecting blocks connected on the same side.

[0012] Furthermore, each of the rubber pads is I-shaped, including two parallel fixed sections and an isolation section perpendicular to the two fixed sections. The isolation section is disposed between the sides of the two connecting blocks that abut against each other. One of the two fixed sections is attached to the outer wall of the two connecting blocks, and the other of the two fixed sections is disposed on the inner wall of the two spring cavities that are attached to each other.

[0013] Furthermore, both upper tilting pads and both lower tilting pads are mounted on the inner wall of the bearing housing via support blocks.

[0014] Furthermore, the contact surfaces between the connecting blocks of the upper and lower tiltable tiles on the same side are curved.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0017] Figure 1 A schematic diagram of the overall structure of a tilting pad sliding bearing with vibration reduction function according to the present invention.

[0018] Figure 2 for Figure 1 A magnified view of part A in the middle.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Bearing housing; 2. Upper tilting pad; 3. Lower tilting pad; 4. Journal; 5. Tension spring; 6. Rubber pad. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0022] This application provides a tilting pad sliding bearing with vibration damping function that is linked to the bearing shell, as described below. Figures 1 to 2 To elaborate in detail.

[0023] Reference Figure 1A type of tilting pad sliding bearing with vibration damping function, comprising a bearing housing 1, the bearing housing 1 including an integrally symmetrically arranged upper and lower housing. Two upper tilting pads 2 are symmetrically arranged on the inner wall of the upper housing, and the two upper tilting pads 2 are arranged symmetrically on the inner wall of the upper housing. Two lower tilting pads 3 are symmetrically arranged on the inner wall of the lower housing, and the two lower tilting pads 3 are arranged symmetrically on the inner wall of the lower housing. The two upper tilting pads 2 and the two lower tilting pads 3 are elastically connected in a one-to-one correspondence. All the bearing pads 3 are mounted on the inner wall of the bearing housing 1 by means of support blocks. The curvature of the back of the upper tilting pad 2 and the lower tilting pad 3 is slightly greater than the curvature of the inner surface of the bearing housing. The connecting ends of the upper tilting pad 2 and the lower tilting pad 3, which are movably connected on the same side, are provided with movable connecting sections. A tension spring 5 for connecting the upper tilting pad 2 and the lower tilting pad 3 is provided between the two movable connecting sections. A journal 4 is provided between the two upper tilting pads 2 and the two lower tilting pads 3. The curvature of the inner surface of the upper tilting pad 2 and the lower tilting pad 3 is slightly less than the curvature of the journal.

[0024] Tilting pad bearings typically consist of 3 to 5 or more arc-shaped pads that can freely tilt at the fulcrum, hence they are also called movable multi-pad bearings or swing bearings. Because the pads can swing freely with changes in speed, load, and bearing temperature, multiple oil wedges are formed around the journal. Furthermore, the pressure of each oil film always points towards the center, resulting in high stability. The clearance between the turbine shaft and the bearing pads is a crucial parameter. Excessive clearance leads to significant oil leakage, affecting the proper establishment of the oil film and increasing shaft vibration. Insufficient clearance easily damages the oil film, causing dry friction and pad wear. The pressure oil film between the bearings cannot be properly established, easily leading to excessively high oil temperature and unstable main shaft operation.

[0025] This invention connects the non-load-bearing bearing with the load-bearing bearing by setting a movable connecting section, so that the gap between the upper tilting bearing 2 and the lower tilting bearing 3 is in a suitable position. Structurally, this ensures that the distance between the upper tilting bearing 2 and the lower tilting bearing 3 is limited, and the gap will not change too much or too little, thus improving the oil film instability. Furthermore, under the connecting action of the telescopic spring, the connection between the upper tilting bearing 2 and the lower tilting bearing 3 remains movable, reducing the probability of misalignment between the movable connecting sections of the upper tilting bearing 2 and the lower tilting bearing 3 due to vibration. Moreover, when the upper tilting bearing 2 and the lower tilting bearing 3 vibrate, they will not deviate too much from their normal working position under the action of the telescopic spring, thereby reducing the vibration amplitude of the bearing and improving the lubrication performance between the upper tilting bearing 2, the lower tilting bearing 3 and the journal 4, thereby improving the stability of the shaft system.

[0026] Among them, reference Figure 1and Figure 2 To connect the upper tilting pad 2 and the lower tilting pad 3 on the same side, the movable connecting sections at the connecting ends of the upper tilting pad 2 and the lower tilting pad 3 on the same side each include an extension section integrally formed with the corresponding upper tilting pad 2 or lower tilting pad 3. Each extension section has a connecting block at the end facing away from the integrally connected tilting pad. The two connecting blocks are arranged parallel to each other, and a tension spring 5 is positioned between the facing sides of the two connecting blocks. Furthermore, the contact surfaces between the connecting blocks of each movable connecting section are curved surfaces with the same curvature as the outer surface of the bearing bush. This prevents one or all bearing bushes from becoming immobile due to friction or obstruction between the contact surfaces of the connecting blocks when the bearing bush vibrates.

[0027] In one embodiment, considering that in order to ensure a stable connection between the upper tilting tile 2 and the lower tilting tile 3 connected on the same side and to prevent positional interference between the connecting blocks, it is necessary to stagger the extensions of the upper tilting tile 2 and the lower tilting tile 3 on the same side. The extension of the upper tilting tile 2 is located on the side of the upper tilting tile 2 facing the end face of the lower tilting tile 3, close to the journal 4, and the extension of the lower tilting tile 3 is located on the side of the lower tilting tile 3 facing the end face of the upper tilting tile 2, away from the journal 4.

[0028] In one embodiment, each of the two connecting blocks has a spring cavity on its opposite side for accommodating one-sided openings of the tension spring 5. The openings of the two spring cavities are directly opposite each other, and both ends of the tension spring 5 are fixed to the sidewalls of the two spring cavities facing each other. A pull ring for fixing the tension spring 5 is provided on the sidewall of the spring cavity facing the opening. Furthermore, it is necessary to consider that even with the tension spring 5, a certain amount of movement space is still required for the upper tilting pad 2 and the lower tilting pad 3 connected on the same side, so as to ensure that the characteristics of the tilting pad bearing itself can be maintained. Therefore, the spring cavity needs to have a certain amount of movement space in the direction perpendicular to the tension spring 5, that is, the diameter of the spring cavity is larger than the cross-sectional diameter of the tension spring 5. In this embodiment, the diameter of the spring cavity is set to be greater than 1.5 times the diameter of the tension spring 5.

[0029] To reduce collisions between connecting blocks, several rubber pads 6 are provided between the opposite sides of two connecting blocks connected on the same side. In this embodiment, two rubber pads 6 are provided between the connecting blocks where the upper tiltable tile 2 and the lower tiltable tile 3 on the same side are connected, respectively placed at the abutment positions of the upper and lower connecting blocks in the spring cavity. To stably fix the rubber pads 6, each rubber pad 6 is I-shaped, including two parallel fixing sections and an isolation section perpendicular to the two fixing sections. The isolation section is located between the abutment sides of the two connecting blocks, one of the two fixing sections is attached to the outer wall of the two connecting blocks, and the other of the two fixing sections is attached to the inner wall of the two spring cavities. The I-shaped rubber pads 6 can stably fix the connecting blocks at their abutment positions, thereby achieving stable vibration reduction between the connecting blocks.

[0030] Due to the presence of oil, an oil film forms on the surface of the fixed section of the rubber pad 6 located on the outer wall of the connecting block. Under the surface tension and pressure of the oil film, the fixed section of the rubber pad 6 can adhere more stably to the surface of the connecting block. In the non-working state, the oil slowly seeps into the gap between the connecting block and the rubber pad 6. In the working state, due to the vibration between the upper tilting pad 2 and the lower tilting pad 3, the connecting blocks and the rubber pad 6 will shift, causing the oil that has seeped into the gap between the rubber pad 6 and the connecting block to be spread on the contact surface between the connecting block and the rubber pad 6 by the shifting connecting blocks. With the lubrication of the oil, the friction between the connecting block and the rubber pad 6 is reduced, thereby reducing the wear of the connecting block and the rubber pad 6.

[0031] In one embodiment, the connecting block has multiple channels for oil inlet and outlet on the side wall corresponding to the spring cavity. When oil enters the spring cavity, the tension spring 5 deforms due to vibration, converting the impact energy into elastic potential energy. However, during the deformation of the tension spring 5, the spring will rub against the oil in the spring cavity, causing some energy to be dissipated as heat in the oil. Furthermore, during the spring's recovery deformation, it will continue to rub against the oil, resulting in another loss of energy as heat in the oil. This makes the energy fed back by the tension spring 5 when it recovers its elastic deformation less than the received impact energy. Consequently, the energy received by the connecting block fixedly connected to the tension spring 5 and the upper tilting pad 2 or lower tilting pad 3 integrally connected to the connecting block during the rebound process is reduced, which means the rebound amplitude is reduced, thereby reducing the vibration amplitude.

[0032] Furthermore, due to the setting of the rubber pad 6, when the upper tilting block 2 or the lower tilting block 3 moves due to vibration, at the beginning of a vibration, the gap between the two connecting blocks will increase, and the internal space enclosed by the spring cavities of the two connecting blocks will change. At this time, the oil in the internal space is not enough to completely fill the internal space enclosed by the two spring cavities, so it will generate suction on the external oil through the channel, thereby allowing the external oil to enter the two spring cavities. When a vibration ends, the two connecting blocks will move closer to each other again under the action of the tension spring 5. At this time, the space in the two spring cavities will return to its original size. At this time, the total amount of oil in the two spring cavities is greater than the total volume of the two spring cavities, so the oil will flow out to the outside of the connecting blocks along the channel. Because the oil in the spring cavity located inside the connecting block generates internal energy and heat due to friction after the spring 5 deforms and recovers its deformation, the oil temperature rises. When external oil enters the spring cavity, the temperature between the oils exchanges, thereby reducing the oil temperature inside the spring cavity. Furthermore, because the oil drawn in has a certain velocity, the external oil entering the spring cavity will agitate the internal oil, thus making the temperature exchange more thorough. During the vibration recovery phase, the oil that has completed the heat exchange will be discharged into the external space again, carrying the heat out to the external oil environment. The external oil environment will also exchange heat with this part of the oil with heat, so that the internal energy heat generated by the oil due to the spring stretching is dissipated to the external environment, accelerating the energy flow and ensuring the efficiency of the oil in the spring cavity in converting the deformation energy of the spring into internal energy. As a result, the energy fed back to the two connecting blocks by the spring's recovery deformation is less than the received impact energy, giving this structure a better vibration reduction effect.

[0033] In some embodiments, the amount of oil is insufficient to enter the spring cavity within the connecting block through the channel. However, external air can be drawn in through the channel. After entering the spring cavity, the air exchanges heat with the oil in the internal space enclosed by the two spring cavities, thereby lowering the temperature of the oil with internal energy and thus reducing its internal energy. During the vibration recovery phase, the air is compressed and discharged from the channel to the external space of the connecting block. The heat carried by the air is dissipated into the external environment, thereby accelerating the energy flow and ensuring the efficiency of the oil in the spring cavity in converting the deformation energy of the spring into internal energy. As a result, the energy fed back to the two connecting blocks by the spring's recovery deformation is always less than the received impact energy, giving this structure a better vibration reduction effect.

[0034] In some embodiments, the number of bearing bushes may be greater than four. In this case, several situations may arise between the load-bearing bearing bushes and the non-load-bearing bearing bushes: the number of load-bearing bearing bushes and non-load-bearing bearing bushes are the same and correspond one-to-one, but there is a situation where a movable connecting block cannot be directly set between the load-bearing bearing bushes and non-load-bearing bearing bushes; and the number of load-bearing bearing bushes and non-load-bearing bearing bushes are different. Therefore, considering this situation, in order to further reduce the impact of vibration on the gaps between each bearing bush, a movable connecting section, the same as described above, is provided between every two adjacent bearing bushes, and the movable connecting sections between two adjacent bearing bushes are connected by a tension spring 5. Furthermore, the contact surface between the connecting blocks of each movable connecting section is a curved surface with the same curvature as the outer surface of the bearing bush, thereby avoiding the situation where one or all bearing bushes cannot move due to mutual friction or obstruction between the contact surfaces of the connecting blocks when the bearing bushes vibrate. In addition, the diameter of the spring cavity must be greater than or equal to twice the cross-sectional diameter of the tension spring 5. Furthermore, the width of the extension section of each movable connection is smaller than the width of the end face of the corresponding integrally connected bearing bush, thereby ensuring that the oil can enter the inner surface of the bearing bush to form an oil film after entering the bearing housing 1.

[0035] In other embodiments, the inner surface of each upper and lower tilting pad is provided with Babbitt alloy blocks. Babbitt alloy is a bearing alloy with hard phase particles uniformly distributed on a soft phase matrix. Its soft phase matrix gives the alloy excellent embedding, compliance, and anti-seize properties. After break-in, the soft matrix concaves inward and the hard particles convex outward, forming tiny gaps between the sliding surfaces, which become oil storage spaces and lubricating oil channels, thus facilitating friction reduction. The convex hard particles act as supports, which is beneficial for load bearing. Compared with other bearing materials, Babbitt alloy has better adaptability and press-fit properties.

[0036] The working principle of this invention is as follows: Without altering the bearing lubrication surface, by changing the side shapes of the upper tilting pad 2 and the lower tilting pad 3, movable connecting sections are provided on the opposite end faces of both the upper and lower tilting pads, which are located on one side. Under the action of the extension sections of these movable connecting sections and the connecting blocks, the gap between the upper tilting pad 2 and the lower tilting pad 3 is positioned appropriately. Structurally, this ensures that the distance between the upper and lower tilting pads 2 and 3 is limited, preventing excessive or insufficient changes in the gap. This improves the oil film instability situation, and further, under the connecting action of the telescopic spring... This design ensures a movable connection between the upper tilting pad 2 and the lower tilting pad 3, reducing the probability of misalignment due to vibration between their movable connecting sections. Furthermore, the springs prevent excessive deviation from their normal operating positions during vibration, thus minimizing the extent of deviation and improving lubrication between the upper and lower tilting pads 2 and 3 and the journal 4, thereby enhancing the stability of the shaft system. Simultaneously, rubber pads 6 are installed between the contact surfaces to reduce the vibration amplitude of non-load-bearing pads, improving the oil film stability between each upper and lower tilting pad and the journal 4, resulting in good vibration damping and load-bearing capacity.

[0037] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A tilting pad sliding bearing with a damping function in which pads are linked, characterized in that, The application relates to a bearing shell, which comprises an upper half shell and a lower half shell arranged symmetrically in one body, two upper tilting pads arranged symmetrically on the inner wall of the upper half shell, two lower tilting pads arranged symmetrically on the inner wall of the lower half shell, elastic connection of the two upper tilting pads and the two lower tilting pads one by one, an active connection section arranged on the connecting end of the upper tilting pad and the lower tilting pad on the same side, a tension spring arranged between the two active connection sections for connecting the upper tilting pad and the lower tilting pad, and a shaft neck arranged between the two upper tilting pads and the two lower tilting pads. The active connection section arranged on the connecting end of the upper tilting pad and the lower tilting pad on the same side comprises an extension section arranged in one body with the corresponding upper tilting pad or lower tilting pad, a connecting block arranged on the end of the extension section away from the tilting pad connected in one body, and two connecting blocks arranged on the side surfaces in parallel and facing each other, and the tension spring is arranged between the side surfaces of the two connecting blocks.

2. A tilting pad sliding bearing with a damping function and a linkage of pads as set forth in claim 1, characterized in that The extension section of the upper tilting pad is arranged on the side of the end surface of the upper tilting pad close to the shaft neck, and the extension section of the lower tilting pad is arranged on the side of the end surface of the lower tilting pad away from the shaft neck.

3. A tilting pad sliding bearing with a damping function and a linkage of pads according to any one of claims 1 or 2, characterized in that The side surfaces of the two connecting blocks are provided with spring cavities with one side opening for accommodating the tension spring, and the openings of the two spring cavities are arranged in parallel, and the two ends of the tension spring are fixed on the side walls of the openings of the two spring cavities.

4. A tilting pad sliding bearing with a damping function and a linkage of pads as set forth in claim 3, characterized in that The side walls of the openings of the spring cavities are provided with pull rings for fixing the tension spring.

5. A tilting pad sliding bearing with a damping function and a linkage of pads as set forth in claim 3, characterized in that The side surfaces of the two connecting blocks connected on the same side are provided with a plurality of rubber pads.

6. A tilting pad sliding bearing with a damping function and a linkage of pads as set forth in claim 5, characterized in that Each rubber pad is in the shape of an I-beam, comprising two fixed sections arranged in parallel and a separation section arranged perpendicularly to the two fixed sections, the separation section is arranged between the side surfaces of the two connecting blocks abutting against each other, one of the two fixed sections is arranged in abutment with the outer wall of the two connecting blocks, and the other of the two fixed sections is arranged in abutment with the inner wall of the two spring cavities.

7. A tilting pad sliding bearing with a damping function and a linkage of pads according to claim 1, characterized in that The two upper tilting pads and the two lower tilting pads are installed on the inner wall of the bearing shell through supporting blocks.

8. A tilting pad sliding bearing with a damping function and a linkage of pads according to claim 1, characterized in that The contact surfaces between the connecting blocks of the upper tilting pads and the connecting blocks of the lower tilting pads on the same side are arranged in curved surfaces.

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