Tilting pad sliding bearing of steam turbine

Abstract

The utility model relates to a tilting-pad sliding bearing of a steam turbine. The tilting-pad sliding bearing comprises a pad body, a pad block and an oil retainer, the multiple tile blocks are evenly distributed on the inner ring of the tile body in the circumferential direction, and the oil retaining rings are arranged on the two axial sides of the tile body. Two adjacent tiles are provided with mounting spaces in the circumferential direction of the inner rings of the tile bodies, shaft lubricating assemblies used for supplying oil to the positions between the tiles and the rotor are arranged in the mounting spaces, oil spraying holes are formed in the shaft lubricating assemblies, and the oil spraying holes are formed towards inlets in the oil inlet sides of the tiles; a jacking shaft device is arranged on the tile block at the bottom of the tile body inner ring and used for supporting the rotor; and the jacking shaft device adopts a one-way valve to supply oil to a jacking shaft oil bag through a tile block side wall channel. The bearing provided by the utility model can enhance the cooling effect of the pads, the temperature of an oil film is easier to adjust and control, and collision and abrasion caused by sudden loss of jacking oil pressure in the starting process can be avoided.

Description

Technical Field

[0001] This utility model relates to the field of steam turbine technology, and in particular to a tilting pad sliding bearing for steam turbines. Background Technology

[0002] Tilting pad sliding bearings in coal-fired turbine units typically maintain daily startup and stable operation through a jacking oil system and a lubrication oil system. The jacking oil system is usually connected to the bearing bush through an oil supply short pipe and sealed with a seal ring. When the jacking oil system experiences faults such as hose rupture or aging seal ring leakage, it is easy to cause the jacking oil to lose pressure, leading to bearing bush rubbing. On the other hand, the lubrication oil system regulates the oil temperature by adjusting the cooling water flow, which is slow and not conducive to timely response. Utility Model Content

[0003] This invention provides a tilting pad sliding bearing for steam turbines, which enhances the cooling effect of the pads, makes the oil film temperature easier to adjust and control, and makes the jacking oil supply pressure more stable, thus avoiding rubbing caused by sudden loss of jacking oil pressure during startup.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A tilting pad sliding bearing for a steam turbine includes a pad body, pad blocks, and an oil retaining ring;

[0006] The aforementioned tiles are configured as multiple units, circumferentially and evenly distributed on the inner ring of the aforementioned tile body, and the aforementioned oil baffle rings are located on both axial sides of the aforementioned tile body;

[0007] Two adjacent bearings are provided with an installation space in the circumferential direction within the bearing body. A lubrication assembly for supplying oil between the bearing and the rotor is provided in the installation space. An oil injection hole is provided in the lubrication assembly and is positioned facing the oil inlet of the bearing.

[0008] The aforementioned bearing, which supports the rotor at the bottom of the inner ring of the bearing, is equipped with a jacking device, which is connected to a high-pressure oil pump in the external jacking oil system. This device supplies oil between the bearing and the rotor to lift the rotor.

[0009] Preferably, the above-mentioned lubrication shaft assembly includes an oil inlet pipe, an oil supply pipe, and a support block;

[0010] The aforementioned oil supply pipe is located within the aforementioned installation space. One end of the aforementioned oil inlet pipe is connected to the aforementioned oil supply pipe, and the other end is connected to the oil passage of the tile body. The upper part of the aforementioned support block is connected to the oil supply pipe, and the lower part is connected to the side wall of the inner ring of the tile body.

[0011] The aforementioned injection holes are located on the aforementioned oil inlet pipe, and there are multiple such holes along the length of the aforementioned oil supply pipe.

[0012] Preferably, the aforementioned jacking device includes a pipe joint, a check valve, and an oil pipe assembly;

[0013] The aforementioned pad has mounting holes on its axially oriented sidewalls, and a top shaft oil bladder is located at the center of the sidewall of the aforementioned pad facing the rotor. An oil passage is provided inside the aforementioned pad, and the inlet and outlet of the aforementioned oil passage are respectively connected to the mounting holes and the top shaft oil bladder.

[0014] The aforementioned pipe fitting is connected to the opening of the aforementioned mounting hole away from the aforementioned oil passage, and the aforementioned pipe fitting is connected to the aforementioned oil pipe assembly.

[0015] The aforementioned one-way valve is installed in the aforementioned mounting hole so that the lubricating oil in the aforementioned oil pipe assembly flows unidirectionally into the aforementioned oil passage.

[0016] Preferably, the pipe fitting is integrally cast with the tile block.

[0017] Preferably, the aforementioned top shaft oil bladder is configured as a fisheye shape or a rhombus shape.

[0018] Preferably, the tubing assembly includes a rigid tube and a flexible metal tube connected together, the rigid tube being connected to the tube fitting, and the flexible metal tube being connected to an external oil pump.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0020] The oil injection holes are positioned so that the oil inlet is facing the oil inlet side of the bearing, allowing the cooled lubricating oil to directly enter between the bearing and the rotor and form an oil film. The initial temperature of the oil film is the temperature of the lubricating oil that enters, which enhances the cooling effect of the bearing. Moreover, the initial temperature of the oil film is not heated by the rotor, making the temperature of the oil film easier to adjust and control. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the bearing in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram showing the orientation of the bearing, rotor, and oil injection hole in an embodiment of this utility model;

[0024] Figure 3 This is a schematic diagram of the overall lubrication shaft assembly in an embodiment of this utility model;

[0025] Figure 4 This is a schematic diagram showing the connection between the top shaft device and the tile block in an embodiment of this utility model;

[0026] Figure 5 This is a schematic diagram of a tile in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the top shaft oil bladder in an embodiment of this utility model.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Bearing body; 2. Bearing block; 21. Oil passage; 22. Mounting hole; 23. Top shaft oil bladder; 3. Oil retaining ring; 4. Installation space; 5. Lubrication shaft assembly; 51. Oil inlet pipe; 52. Oil supply pipe; 521. Oil injection hole; 53. Support block; 6. Top shaft device; 61. Pipe joint; 62. One-way valve; 63. Oil pipe assembly; 631. Rigid pipe; 632. Metal flexible hose; 7. Rotor. Detailed Implementation

[0030] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] like Figures 1-6As shown in the figure, a specific embodiment of this utility model discloses a tilting pad sliding bearing for a steam turbine, including a pad body 1, pad blocks 2, and an oil retaining ring 3. Multiple pad blocks 2 are arranged circumferentially and evenly distributed on the inner ring of the pad body 1. Specifically, the pad blocks 2 are movably fixed to the inner ring of the pad body 1 by axial positioning pins at the side center, thereby enabling slight circumferential oscillation and absorbing the unbalanced force of the rotor 7. Two oil retaining rings 3 are installed on the axial sides of the pad body 1 respectively, used to block the axial splashing of top shaft oil and lubricating oil inside the bearing. An installation space 4 is provided circumferentially on the inner ring of the pad body 1 between two adjacent pad blocks 2. A lubrication assembly 5 is provided in the installation space 4 to supply lubricating oil between the pad blocks 2 and the rotor 7, thereby forming an oil film and ensuring the stable and safe operation of the rotor 7. The lubrication assembly 5 is provided with an oil injection hole 521. In the prior art, the oil injection hole 521 is oriented towards the center of the rotor 7 (e.g., ...). Figure 2 (As indicated by A in the diagram), because the rotor 7 rotates under the drive of hot steam, its own temperature is relatively high. The lubricating oil is sprayed onto the rotor 7 and then enters the oil film inlet. At this point, the lubricating oil has been heated by the high-temperature rotor 7, and its temperature has increased, which is detrimental to the cooling of the bearing 2 and the control of the oil film temperature. In this embodiment, the oil injection hole 521 is positioned facing the oil inlet of the bearing 2 (e.g., ...). Figure 2 (in the direction indicated by B in the middle), so that the cooling lubricating oil directly enters between the bearing 2 and the rotor 7 and forms an oil film. The initial temperature of the oil film is the temperature of the lubricating oil that enters, which can enhance the cooling effect of the bearing 2. Moreover, the initial temperature of the oil film is not heated by the rotor 7, and the temperature of the oil film is easier to adjust and control.

[0034] In this embodiment, a structure of five tiles 2 is adopted, and they are evenly distributed with equal central angles based on the top support point. This makes the bottom two tiles 2 symmetrically distributed along the vertical direction of the bearing center, realizing the bearing between the tiles and effectively increasing the bearing capacity. Furthermore, the top center of the tile body 1 corresponds to the center of the tile 2, which facilitates direct measurement of the bearing top clearance.

[0035] Specifically, the lubrication shaft assembly 5 includes an oil inlet pipe 51, an oil supply pipe 52, and a support block 53. The oil supply pipe 52 is located within the installation space 4. One end of the oil inlet pipe 51 is connected to the oil supply pipe 52, and the other end is connected to the oil passage 21 provided inside the bearing body 1. The upper part of the support block 53 is connected to the outer wall of the oil supply pipe 52, and the lower part is connected to the side wall of the inner ring of the bearing body 1. It is used to fix the oil supply pipe 52 and ensure that the orientation of the oil injection hole 521 on the oil supply pipe 52 is fixed. Preferably, multiple oil injection holes 521 are provided, and multiple oil inlet pipes 51 are arranged along the length direction of the oil supply pipe 52. Correspondingly, the length of the oil inlet pipe 51 is consistent with the axial length of the bearing 2, so that the length of the oil inlet pipe 51 is consistent with the length of the oil inlet on the oil inlet side of the bearing 2, thereby stably covering the length of the oil inlet on the oil inlet side of the bearing 2, so that the oil film can be stably formed.

[0036] Specifically, a top shaft device 6 is also provided on the pad 2 that supports the rotor 7 at the bottom of the inner ring of the pad body 1. The top shaft device 6 serves as the oil supply end of the top shaft oil system. Under the action of the high-pressure oil pump in the top shaft oil system, the oil enters the bearing through the top shaft device 6 to form a static pressure oil film. This prevents the rotor 7 from slowly increasing in speed from zero during the unit startup, and the relative speed between the rotor 7 and the pad 2 is slow in the initial stage, thus preventing the formation of an oil film and avoiding direct contact between the rotor 7 and the pad 2.

[0037] Specifically, the top shaft device 6 includes a one-way valve 62, a pipe joint 61, and an oil pipe assembly 63. The side wall of the bearing 2 along its axial direction is provided with a mounting hole 22. The side wall of the bearing 2 facing the rotor 7 is provided with a top shaft oil bladder 23. An oil passage 21 is provided inside the bearing 2. The inlet and outlet of the oil passage 21 are connected to the mounting hole 22 and the top shaft oil bladder 23, respectively. The pipe joint 61 is installed at the opening of the mounting hole 22. The one-way valve 62 is installed inside the mounting hole 22. One end of the oil pipe assembly 63 is connected to the pipe joint 61, and the other end is connected to the dual filter in the top shaft subsystem to form a complete oil supply system. The one-way valve 62 installed in the mounting hole 22 is to ensure one-way flow of lubricating oil, preventing the lubricating oil in the bearing from flowing back after the high-pressure oil pump in the oil supply device stops working. This ensures the oil pressure in the top shaft oil bladder 23, thereby ensuring the pressure of the static oil film formed between the bearing 2 and the rotor 7, preventing the bearing 2 and the rotor 7 from rubbing against each other, and avoiding rubbing caused by a sudden loss of top shaft oil pressure during startup.

[0038] Preferably, the tubing assembly 63 includes a rigid tube 631 and a flexible metal tube 632 connected together, wherein the rigid tube 631 is connected to the pipe joint 61 and the flexible metal tube is connected to the filter, thereby allowing the pipe joint 61 and the tile 2 to have free movement space, allowing the tile 2 to swing without affecting the swing of the tile 2.

[0039] Because the bearing pad 2 will wobble slightly during bearing operation, and the transition joint of the traditional top shaft device 6 is threaded to the bearing pad 2, the connection between the two is prone to loosening, which will be accompanied by pressure tilting outward, resulting in insufficient top shaft oil pressure. As a result, the oil film between the rotor 7 and the bearing pad 2 will be thinner, or even come into contact, causing wear between the two and causing a series of operational accidents. Preferably, in this embodiment, the pipe joint 61 and the bearing pad 2 are integrally cast, avoiding relative movement between the two, so that the pipe joint 61 and the bearing pad 2 move synchronously, ensuring the reliability and stability of the connection.

[0040] Preferably, such as Figure 6 As shown, the top shaft oil bladder 23 is configured in the shape of a fisheye or a rhombus to increase the contact area between the top shaft oil and the rotor 7 and increase the pressure of the top shaft oil.

[0041] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A tilting pad sliding bearing for a steam turbine, characterized in that, Includes the bearing body, bearing blocks, and oil baffle ring; The tile blocks are configured as multiple blocks, which are circumferentially and evenly distributed on the inner ring of the tile body, and the oil baffle ring is provided on both axial sides of the tile body; Two adjacent bearings are provided with an installation space in the circumferential direction within the bearing body. A lubrication assembly for supplying oil between the bearing and the rotor is provided in the installation space. An oil injection hole is provided in the lubrication assembly and is positioned facing the oil inlet of the bearing. A jacking device is provided on the bearing block that supports the rotor at the bottom of the inner ring of the bearing block. It is connected to a high-pressure oil pump in the external jacking oil system and is used to supply oil between the bearing block and the rotor to lift the rotor.

2. The turbine tilting pad sliding bearing according to claim 1, characterized in that, The lubrication shaft assembly includes an oil inlet pipe, an oil supply pipe, and a support block; The oil supply pipe is located within the installation space. One end of the oil inlet pipe is connected to the oil supply pipe, and the other end is connected to the oil passage of the tile body. The upper part of the support block is connected to the oil supply pipe, and the lower part is connected to the side wall of the inner ring of the tile body. The oil injection holes are located on the oil inlet pipe, and there are multiple holes arranged along the length of the oil supply pipe.

3. The turbine tilting pad sliding bearing according to claim 1, characterized in that, The top shaft assembly includes a pipe joint, a check valve, and an oil pipe assembly; The side wall of the bearing is provided with mounting holes along the axial direction, and a top shaft oil bladder is provided at the center of the side wall of the bearing facing the rotor. An oil passage is provided inside the bearing, and the inlet and outlet of the oil passage are respectively connected to the mounting holes and the top shaft oil bladder. The pipe fitting is connected to the opening of the mounting hole away from the oil passage, and the pipe fitting is connected to the oil pipe assembly; The one-way valve is disposed in the mounting hole so that the lubricating oil in the oil pipe assembly flows into the oil passage in one direction.

4. The turbine tilting pad sliding bearing according to claim 3, characterized in that, The pipe fitting is integrally cast with the tile block.

5. The turbine tilting pad sliding bearing according to claim 3, characterized in that, The top shaft oil bladder is configured to be fish-eye shaped or diamond-shaped.

6. The turbine tilting pad sliding bearing according to claim 3, characterized in that, The tubing assembly includes a rigid tube and a flexible metal tube connected together. The rigid tube is connected to the pipe fitting, and the flexible metal tube is connected to an external oil pump.

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