Elastic thrust bearing device for nuclear power circulating water pump

Abstract

The utility model discloses an elastic thrust bearing device for a nuclear power circulating water pump, which is arranged on a pump shaft of the nuclear power circulating water pump and comprises a thrust pad, a base connected with the thrust pad and a bearing elastic supporting structure arranged between the thrust pad and the base, and the bearing elastic supporting structure comprises an elastic pivot piece, an elastic plate and a base plate. According to the elastic thrust bearing device, the bearing elastic supporting structure is adopted, the rigidity of the bearing elastic supporting structure is larger than that of a belleville spring, the deformation amount is small under the same axial load, and due to the arrangement of the bearing elastic supporting structure, the problem of fretting wear between the thrust pad and the base can be effectively solved; the bearing elastic supporting structure can deform under static and dynamic axial loads, can be automatically leveled, is good in uniform load performance and bidirectional rotation bearing capacity, can prolong the service life of the elastic thrust bearing device, ensures the stability of the nuclear power circulating water pump in the operation process, and reduces unexpected faults of the circulating water pump.

Description

Technical Field

[0001] The utility model relates to the field of thrust bearings for nuclear power circulating water pumps, in particular to an elastic thrust bearing device for nuclear power circulating water pumps. Background Art

[0002] The circulating water pump is the "heart" of the three-circuit nuclear power plant. Its function is to provide the necessary cooling water to the condenser of the steam turbine and the auxiliary cooling water system. The circulating water pump is a large-scale equipment. Each unit of the nuclear power plant is usually equipped with two circulating water pumps working simultaneously, without a standby pump. The stable and reliable operation of the pump is extremely important for the economy and safety of the nuclear power plant. The circulating water pump is usually composed of a motor, a gearbox, a pump body, a water inlet flow channel, a volute flow channel, and supporting pipeline instruments. The circulating water pump is equipped with a thrust bearing. The pump and the gearbox can be equipped with a thrust bearing together, or each can be equipped with a thrust bearing separately. The thrust bearing can be a sliding bearing or a rolling bearing, but for large pumps, especially circulating water pumps, the axial force generated during the startup and operation process is large, so the reliability of the selected rolling bearing is poor. The nuclear power plant circulating water pump selects rolling bearings as thrust bearings, which are prone to unexpected failures. All of them are caused by the damage of rolling thrust bearings, resulting in unexpected shutdown of the nuclear power plant, which has a huge impact on the safe and stable operation of the nuclear power plant, and also causes serious economic losses. Therefore, developing a set of thrust bearings with long service life and low failure rate is crucial for the safe, reliable and stable operation of nuclear power plants.

[0003] The radial and thrust combined bearing structure of the original nuclear power circulating water pump is supported by butterfly springs. The load size of the circulating water pump changes periodically, and the change cycle is relatively short (multiple tidal changes in a day). During the load change process, the butterfly spring position repeatedly "contracts and extends", causing the contact surface to be repeatedly ground, resulting in wear and deformation of the contact surface. After the thrust bearing of a circulating water pump in a nuclear power plant was used for a period of time, the upper and lower bearing surfaces of the butterfly spring in the thrust bearing were found to be crushed and deformed to varying degrees. During the daily operation of the pump unit, the metal content of the bearing lubricant was too high, affecting the safe and reliable operation of the equipment. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide an elastic thrust bearing device for a nuclear power circulating water pump.

[0005] The technical solution adopted by the utility model to solve the technical problem is: constructing an elastic thrust bearing device for a nuclear power circulating water pump, which is arranged on the pump shaft of the nuclear power circulating water pump, and includes a thrust pad, a base connected to the thrust pad, and a bearing elastic support structure arranged between the thrust pad and the base, and the bearing elastic support structure includes an elastic pivot, an elastic plate and a pad;

[0006] The elastic pivot member is connected to the thrust washer, and the end surface of the elastic pivot member facing away from the thrust washer is an arc-shaped surface;

[0007] The pad is connected to the base, the elastic plate is installed on the end surface of the pad facing the thrust washer, and the end surface of the elastic plate facing away from the pad abuts against the end surface of the elastic pivot member facing away from the thrust washer.

[0008] In some embodiments, an oil groove is formed on the end surface of the elastic plate facing the backing plate.

[0009] In some embodiments, a first limiting groove is formed on the end surface of the thrust washer facing the base, and a second limiting groove corresponding to the first limiting groove is formed on the end surface of the base facing the thrust washer.

[0010] The elastic pivot member is installed in the first limiting groove, and the elastic plate and the pad are both installed in the second limiting groove.

[0011] In some embodiments, the thrust washer is connected to the base via a first connecting member, the elastic pivot member is connected to the thrust washer via a second connecting member, and the pad is connected to the base via a third connecting member.

[0012] In some embodiments, the number of the bearing elastic support structures is 7, and the 7 bearing elastic support structures are evenly spaced about the central axis of the pump shaft of the nuclear power circulating water pump.

[0013] In some embodiments, the elastic thrust bearing device further includes a thrust head and an oil retaining cylinder;

[0014] The thrust head is arranged on a side of the thrust bushing away from the base, and the thrust head is sleeved on the pump shaft;

[0015] The oil retaining cylinder is arranged between the thrust head and the pump shaft.

[0016] In some embodiments, the elastic thrust bearing device further comprises a bearing housing, a guide pad, and a radial pad;

[0017] The radial bushing, the guide bushing, and the bearing housing are sequentially arranged outside the thrust head from the inside to the outside, and the upper end of the guide bushing is connected to the bearing housing.

[0018] In some embodiments, a wedge block is provided between the radial pad and the guide pad.

[0019] In some embodiments, the elastic thrust bearing device further includes a seal and a cooler;

[0020] The sealing member is mounted on the upper end of the guide shoe and is detachably connected to the guide shoe;

[0021] The cooler is installed in the bearing housing.

[0022] In some embodiments, the elastic pivot member, the elastic plate and the backing plate are all made of spring steel.

[0023] The implementation of the utility model has the following beneficial effects: the elastic thrust bearing device adopts a bearing elastic support structure, the rigidity of the bearing elastic support structure is larger than that of the butterfly spring, the deformation is smaller under the same axial load, and the setting of the bearing elastic support structure can effectively avoid the problem of micro-wear between the thrust pad and the base, the bearing elastic support structure can deform under both static and dynamic axial loads, can automatically level, has good load-balancing performance, and has good bidirectional rotation bearing capacity, the temperature difference of the bearing elastic support structure does not exceed 3°C, the operating temperature is low, and the temperature difference of the bearing pad can be effectively controlled. The setting of the bearing elastic support structure can increase the service life of the elastic thrust bearing device, ensure the stability of the nuclear power circulating water pump during operation, and reduce unexpected failures of the circulating water pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the utility model, the utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the utility model, and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0025] Figure 1 This is a sectional view of the overall structure of the elastic thrust bearing device used for a nuclear power circulating water pump of the utility model;

[0026] Figure 2 It is a structural schematic diagram of the bearing elastic support structure. DETAILED DESCRIPTION

[0027] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0028] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0029] Reference Figure 1 and Figure 2 , is an elastic thrust bearing device for a nuclear power circulating water pump in some embodiments of the utility model, which is arranged on the pump shaft 4 of the nuclear power circulating water pump, and mainly includes a thrust pad 1, a base 2 connected to the thrust pad 1, and a bearing elastic support structure 3 arranged between the thrust pad 1 and the base 2, and the bearing elastic support structure 3 includes an elastic pivot 31, an elastic plate 32 and a pad 33. It can be understood that since the radial and thrust combined bearing structure of the original nuclear power circulating water pump adopts a butterfly spring support, the load size of the circulating water pump changes periodically, and the change cycle is relatively short. During the load change process of the butterfly spring position, the support structure repeatedly "contracts and extends", causing the contact surface to be repeatedly ground, causing the contact surface to wear and deform, affecting the safe and reliable operation of the equipment. Therefore, in this application, the bearing elastic support structure 3 is used to replace the butterfly spring position to ensure the safe and reliable operation of the nuclear power circulating water pump.

[0030] Among them, the elastic pivot member 31 is connected to the thrust washer 1, and the end face of the elastic pivot member 31 facing away from the thrust washer 1 is an arc-shaped surface, the pad 33 is connected to the base 2, and the elastic plate 32 is installed on the end face of the pad 33 facing the thrust washer 1, and the end face of the elastic plate 32 facing away from the pad 33 is abutted against the end face of the elastic pivot member 31 facing away from the thrust washer 1. It can be understood that the end face of the elastic plate 32 facing away from the pad 33 is a plane, and the end face of the elastic pivot member 31 facing away from the thrust washer 1 is an arc-shaped surface. The elastic pivot member 31 and the elastic plate 32 are matched with arc surfaces, so that the thrust washer 1 can produce a certain inclination in the circumferential and radial directions, and also make the bearing elastic support structure 3 as a whole deformable under static and dynamic axial loads, and can be automatically leveled and adjusted during operation, with good load-balancing performance, instead of repeatedly contracting and extending during load changes like a butterfly spring, causing the contact surface of the butterfly spring to wear and deform.

[0031] In addition, the setting of the pad 33 can be such that under special working conditions, if micro-wear occurs between the thrust washer 1 and the base 2, another pad 33 of different specifications can be replaced according to the degree of wear to avoid further damage between the thrust washer 1 and the base 2. By directly replacing the pad 33, the replacement cost can be reduced.

[0032] In this embodiment, in order to prevent the elastic plate 32 from being unable to be disassembled due to oil film adsorption, an oil groove 321 is opened on the end surface of the elastic plate 32 facing the pad 33 to allow air to enter and facilitate disassembly.

[0033] More specifically, Figure 2 As shown, the thrust washer 1 is connected to the base 2 through a first connecting member, which may be a first pin. The first pin may be connected to the pin hole 23 of the thrust washer 1 so that the thrust washer 1 is positioned on the base 2 through the first pin. The number of the first pins may be multiple, and the gap between the thrust washer 1 and the base 2 may be adjusted by adjusting the multiple first pins to adjust the contact degree between the elastic pivot 31 and the elastic plate 32. The elastic pivot 31 is connected to the thrust washer 1 through a second connecting member 311, which is a screw. The elastic pivot 31 may be fixed to the lower end surface of the thrust washer 1 through the screw to ensure that the thrust washer 1 of the elastic thrust bearing device can be deformed under any suitable design load. In addition, the pad 33 is connected to the base 2 through a third connecting member, and a mounting hole 331 for mounting the third connecting member is provided on the pad 33. The third connecting member may be a second pin, and the second pin is used for positioning between the pad 33 and the base 2.

[0034] In some embodiments, the thrust washer 1, the elastic pivot member 31, the elastic plate 32, and the backing plate 33 are matched to ensure an overall height difference.

[0035] Furthermore, Figure 2As shown, a first limiting groove 11 is provided on the end surface of the thrust washer 1 facing the base 2, a second limiting groove 21 corresponding to the first limiting groove 11 is provided on the end surface of the base 2 facing the thrust washer 1, an elastic pivot 31 is installed in the first limiting groove 11, and an elastic plate 32 and a pad 33 are both installed in the second limiting groove 21. The first limiting groove 11 and the second limiting groove 21 limit the bearing elastic support structure 3 together, that is, the elastic pivot 31 will not have a relative micro-motion relative to the thrust washer 1, and the elastic plate 32 and the pad 33 will not have a relative micro-motion relative to the base 2, which can effectively avoid the problem of micro-motion wear of the thrust washer 1 and the base 2.

[0036] In this embodiment, the number of the bearing elastic support structures 3 is 7, and the 7 bearing elastic support structures 3 are evenly spaced about the central axis of the pump shaft 4 of the nuclear power circulating water pump. In some other embodiments, the number of the bearing elastic support structures 3 can be set according to actual application conditions, and is not specifically limited here.

[0037] Preferably, the elastic pivot member 31 , the elastic plate 32 and the backing plate 33 are all made of spring steel, which has the advantages of high elasticity, good wear resistance, high tensile strength and the like.

[0038] In general, the elastic thrust bearing device adopts a bearing elastic support structure 3, which has a larger stiffness than a butterfly spring, and a smaller deformation under the same axial load. The setting of the bearing elastic support structure 3 can effectively avoid the problem of micro-wear between the thrust pad 1 and the base 2. The bearing elastic support structure 3 can deform under both static and dynamic axial loads, can automatically level, has good load-balancing performance, and has good bidirectional rotation bearing capacity. The temperature difference of the bearing elastic support structure 3 does not exceed 3°C, and the operating temperature is low, which can effectively control the temperature difference of the bearing pad. The setting of the bearing elastic support structure 3 can increase the service life of the elastic thrust bearing device, ensure the stability of the nuclear power circulating water pump during operation, and reduce unexpected failures of the circulating water pump.

[0039] In addition, if Figure 1 As shown, the elastic thrust bearing device also includes a thrust head 51 and an oil retaining cylinder 52. The thrust head 51 is arranged on the side of the thrust washer 1 away from the base 2, and the thrust head 51 is sleeved on the pump shaft 4. The top of the thrust head 51 and the pump shaft 4 of the nuclear power circulating water pump can be connected through a locking nut, and the thrust head 51 and the pump shaft 4 can transmit torque through a key. The oil retaining cylinder 52 is arranged between the thrust head 51 and the pump shaft 4, and the function of the oil retaining cylinder 52 is to prevent the lubricating oil in the bearing chamber from overflowing during operation.

[0040] Furthermore, the elastic thrust bearing device further comprises a bearing housing 53, a guide shoe 54, and a radial shoe 55. The radial shoe 55, the guide shoe 54, and the bearing housing 53 are sequentially arranged outside the thrust head 51 from the inside to the outside, and the upper end of the guide shoe 54 is connected to the bearing housing 53. The bearing housing 53 can be used to support the guide shoe 54 and serve as a bearing oil tank, and also as a shell of the elastic thrust bearing device. The guide shoe 54 is used to fix the radial shoe 55, and the radial shoe 55 is used to withstand the radial force generated during the operation of the circulating water pump.

[0041] A wedge block 56 is provided between the radial bushing 55 and the guide bushing 54 , and the gap between the radial bushing 55 and the guide bushing 54 can be adjusted by the wedge block 56 .

[0042] The elastic thrust bearing device also includes a seal 57 and a cooler 58. The seal 57 is installed at the upper end of the guide shoe 54 and is detachably connected to the guide shoe 54. The seal 57 prevents external dust from entering the bearing housing 53. The radial shoe 55 can be inspected and repaired by opening the seal 57, making it more convenient to adjust the shoe gap and replace the radial shoe 55. The cooler 58 is installed in the bearing housing 53. The function of the cooler 58 is to remove the heat generated by the lubricating oil during the operation of the bearing by the cooling water circulating in the cooler 58.

[0043] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should fall within the scope of the claims of the utility model.

Claims

1. An elastic thrust bearing device for a nuclear power circulating water pump, arranged on a pump shaft (4) of the nuclear power circulating water pump, characterized in that: The invention comprises a thrust washer (1), a base (2) connected to the thrust washer (1), and a bearing elastic support structure (3) arranged between the thrust washer (1) and the base (2), wherein the bearing elastic support structure (3) comprises an elastic pivot member (31), an elastic plate (32) and a pad (33); The elastic pivot member (31) is connected to the thrust washer (1), and the end surface of the elastic pivot member (31) facing away from the thrust washer (1) is an arc-shaped surface; The pad (33) is connected to the base (2), the elastic plate (32) is installed on the end surface of the pad (33) facing the thrust washer (1), and the end surface of the elastic plate (32) facing away from the pad (33) abuts against the end surface of the elastic pivot member (31) facing away from the thrust washer (1).

2. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 1, characterized in that: An oil groove (321) is provided on the end surface of the elastic plate (32) facing the pad (33).

3. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 1, characterized in that: A first limiting groove (11) is provided on the end surface of the thrust washer (1) facing the base (2), and a second limiting groove (21) corresponding to the first limiting groove (11) is provided on the end surface of the base (2) facing the thrust washer (1); The elastic pivot member (31) is installed in the first limiting groove (11), and the elastic plate (32) and the pad (33) are both installed in the second limiting groove (21).

4. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 1, characterized in that: The thrust washer (1) is connected to the base (2) via a first connecting member, the elastic pivot member (31) is connected to the thrust washer (1) via a second connecting member (311), and the pad (33) is connected to the base (2) via a third connecting member.

5. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 1, characterized in that: The number of the bearing elastic support structures (3) is 7, and the 7 bearing elastic support structures (3) are evenly spaced about the central axis of the pump shaft (4) of the nuclear power circulating water pump.

6. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 1, characterized in that: The elastic thrust bearing device also includes a thrust head (51) and an oil retaining cylinder (52); The thrust head (51) is arranged on a side of the thrust washer (1) away from the base (2), and the thrust head (51) is sleeved on the pump shaft (4); The oil retaining cylinder (52) is arranged between the thrust head (51) and the pump shaft (4).

7. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 6, characterized in that: The elastic thrust bearing device also includes a bearing housing (53), a guide bush (54), and a radial bush (55); The radial bushing (55), the guide bushing (54), and the bearing housing (53) are sequentially arranged outside the thrust head (51) from the inside to the outside, and the upper end of the guide bushing (54) is connected to the bearing housing (53).

8. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 7, characterized in that: A wedge block (56) is provided between the radial bush (55) and the guide bush (54).

9. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 7, characterized in that: The elastic thrust bearing device also includes a seal (57) and a cooler (58); The sealing member (57) is mounted on the upper end of the guide shoe (54) and is detachably connected to the guide shoe (54); The cooler (58) is installed in the bearing housing (53).

10. The elastic thrust bearing device for a nuclear power circulating water pump according to claim 1, characterized in that: The elastic pivot member (31), the elastic plate (32) and the pad (33) are all made of spring steel.

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