Oil seal device for bearing box of industrial steam turbine

Abstract

The utility model relates to the technical field of sealing devices, in particular to an industrial steam turbine bearing box oil seal device which comprises an oil seal inner baffle, an oil seal center baffle and an oil seal outer baffle which are sequentially arranged from inside to outside. A plurality of oil seal inner ring grooves are formed between the oil seal inner baffle and the oil seal center baffle, a plurality of oil seal outer ring grooves are formed between the oil seal center baffle and the oil seal outer baffle, oil seal pressurization radial blades are arranged between the oil seal center baffle and the oil seal outer ring grooves, and the bearing box is arranged between the oil seal inner baffle and the oil seal outer baffle. An oil return ring groove is formed in the position, corresponding to the oil seal center baffle, in the bearing box, and the oil return ring groove extends downwards and outwards to be provided with an oil return hole. The sealing effect of the turbine bearing box is improved, leakage of lubricating oil is prevented, and operation safety of equipment is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing devices, in particular to an oil sealing device for a bearing box of an industrial steam turbine. Background Art

[0002] Industrial steam turbines are widely used in the chemical industry, particularly in large-scale refineries, to reduce energy losses, conserve energy, meet production process gas parameter requirements, and achieve steam network balance. The seal quality of industrial steam turbine bearing housing oil seal assemblies, a key sealing component of the turbine bearing housing, significantly impacts the normal operation of the equipment and safe production.

[0003] When the turbine is operating, the rotor's turbulent motion causes the lubricating oil in the bearing housing to splash, causing it to leak through the gap between the rotor and the bearing housing. Conventional bearing housing oil seals often utilize a labyrinth seal design. This design creates a seal by machining a concave-convex ring groove into the oil seal assembly and adjusting the radial clearance with the bearing housing seal. The splashed lubricating oil within the bearing housing is gradually decompressed through the groove and the bearing housing gap, effectively sealing the lubricating oil. This sealing design has certain drawbacks. First, it requires a high radial clearance between the seal assembly. Thermal expansion during operation and bearing housing deformation can cause the seal clearance to fluctuate, reducing sealing effectiveness and causing lubricating oil leakage. Second, this type of seal is a non-contact, passive seal, making it extremely difficult to achieve complete leakage during operation. Leaked lubricating oil accumulates outside the bearing housing, particularly near the turbine side, where it accumulates in the turbine insulation. When exposed to high temperatures, it vaporizes and produces fumes. Large amounts of leakage can easily cause fires, posing a safety hazard. Utility Model Content

[0004] The purpose of the utility model is to solve the problems existing in the prior art and provide an industrial steam turbine bearing box oil seal device, which improves the sealing effect of the turbine bearing box, prevents lubricating oil leakage, and ensures the safe operation of the equipment.

[0005] The utility model provides an industrial steam turbine bearing box oil seal device, comprising an oil seal and a bearing box, the oil seal is sleeved on the outer periphery of the turbine rotor, the bearing box is sleeved on the outer periphery of the oil seal, the oil seal comprises an oil seal inner baffle, an oil seal center baffle and an oil seal outer baffle, the oil seal inner baffle, the oil seal center baffle and the oil seal outer baffle are arranged in sequence from the inside to the outside, a plurality of oil seal inner ring grooves are arranged between the oil seal inner baffle and the oil seal center baffle, a plurality of oil seal outer ring grooves are arranged between the oil seal center baffle and the oil seal outer baffle, an oil seal booster radial blade is arranged between the oil seal center baffle and the oil seal outer ring groove, the bearing box is placed between the oil seal inner baffle and the oil seal outer baffle, and is wrapped around the outer periphery of the oil seal center baffle, the oil seal inner ring groove and the oil seal outer ring groove, an oil return ring groove is arranged in the bearing box corresponding to the oil seal center baffle, and an oil return hole is arranged in the oil return ring groove extending downward and outward.

[0006] The oil seal is sleeved on the outer periphery of the turbine rotor and rotates with the turbine rotor. The bearing housing is placed on the outer periphery of the oil seal and does not rotate with the oil seal. When the oil seal rotates with the turbine rotor, the gap between the inner baffle of the oil seal and the inner wall of the bearing housing is small, which prevents some lubricating oil from leaking. At the same time, centrifugal force throws some lubricating oil back into the bearing housing, but some lubricating oil still leaks outward along the gap between the oil seal and the bearing housing. This leaked lubricating oil enters the labyrinth seal formed by the inner wall of the bearing housing in the inner ring groove of the oil seal. After decompression, some of the leaked lubricating oil contacts the center baffle of the oil seal and enters the oil return ring groove of the bearing housing oil seal, and then returns to the bearing housing through the oil return hole of the bearing housing oil seal. However, some lubricating oil still continues to leak out through the oil return ring groove of the bearing box oil seal. After this part of the lubricating oil enters the oil seal booster radial blades, it forms a vortex under the action of centrifugal force and the oil seal booster radial blades, and the lubricating oil is thrown out axially. After encountering the oil seal center baffle, part of the lubricating oil is thrown by the center baffle to the bearing box oil return ring groove of the bearing box oil seal under the action of centrifugal force, and returns to the bearing box through the bearing box oil seal return hole; the remaining lubricating oil collides with the center baffle and returns to the oil seal booster radial blades again. After multiple cycles, it returns to the bearing box through the bearing box oil seal return hole.

[0007] The arc-shaped grooves on the oil seal's booster radial blades, the oil seal's central baffle, and the oil seal's outer ring grooves form a vortex chamber. Centrifugal force causes the lubricating oil to swirl between the vortex chamber and the oil seal's central baffle, thereby continuously increasing the lubricating oil's pressure.

[0008] The oil seal booster radial blades are interference fit with the oil seal outer ring groove, ensuring that the lubricating oil in the vortex cavity is converted into high-pressure oil under the action of centrifugal force.

[0009] The oil seal is interference-fitted with the turbine rotor, so that the oil seal rotates synchronously with the turbine rotor without the need for external power to drive the oil seal to rotate.

[0010] The size of the oil return ring groove and the oil return hole is proportional to the amount of lubricating oil leakage. The amount of lubricating oil leakage is determined through calculation and experimentation, and the size of the oil return ring groove and the oil return hole is determined to ensure that the leaked lubricating oil returns smoothly to the bearing box.

[0011] The oil seal's booster radial blades are provided with arc-shaped grooves along the axial direction, with the opening of the arc-shaped grooves facing the oil seal's central baffle. After lubricating oil enters the oil seal's booster radial blades, the presence of gas, centrifugal force, and the action of the oil seal's booster radial blades create a vortex within the arc-shaped grooves. As the oil seal's booster radial blades rotate continuously, a localized high-pressure zone forms within the arc-shaped grooves. Because the oil seal's outer ring groove and the bearing housing's inner wall form a labyrinth seal, this acts as a throttling mechanism. The gas within the high-pressure zone prevents further outward leakage of lubricating oil and accelerates the return of any leaked lubricating oil through the oil return ring groove and the oil return hole into the bearing housing.

[0012] The inner wall of the bearing box is in clearance with the oil seal. This design is a non-contact seal, which is wear-free during operation, does not require special maintenance, and has a long service life.

[0013] The gap between the inner wall of the bearing box and the oil seal is 0.5-2 mm.

[0014] The number of the inner ring grooves of the oil seal is at least four, forming a multi-stage pressure reduction to prevent lubricating oil leakage.

[0015] The number of the oil seal outer ring grooves is at least two, forming multi-stage pressure reduction to prevent lubricating oil leakage.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The utility model prevents leakage of some lubricating oil by arranging an inner baffle plate of the oil seal, a center baffle plate of the oil seal and an outer baffle plate of the oil seal, forms a labyrinth seal with the inner wall of the bearing box by arranging an inner ring groove of the oil seal and an outer ring groove of the oil seal, and prevents leakage of some lubricating oil after decompression, and forms a vortex by arranging an oil seal pressurizing radial blade, which is acted upon by centrifugal force and radial blade, and the lubricating oil is thrown out axially. After encountering the center baffle plate of the oil seal, part of the lubricating oil is thrown from the center baffle plate to the oil return ring groove of the bearing box oil seal under the action of centrifugal force, thereby further preventing leakage of lubricating oil, and realizing recovery of leaked oil and avoiding waste by arranging the oil return ring groove and the oil return hole.

[0018] 2. An arc-shaped groove is provided axially on the oil seal's booster radial blades, with the opening of the arc-shaped groove facing the oil seal's center baffle. After the lubricating oil enters the oil seal's booster radial blades, a vortex is formed in the arc-shaped groove due to the presence of gas, centrifugal force, and the action of the oil seal's booster radial blades. As the oil seal's booster radial blades rotate continuously, a local high-pressure area forms in the arc-shaped groove. Because the oil seal's outer ring groove and the bearing housing's inner wall form a labyrinth seal, which acts as a throttling force, the gas in the high-pressure area prevents further outward leakage of the lubricating oil and accelerates the leaked lubricating oil back into the bearing housing through the oil return ring groove and the oil return hole.

[0019] 3. The inner wall of the bearing box and the oil seal are well matched. This design is a non-contact seal, which is wear-free during operation, does not require special maintenance, and has a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the three-dimensional structure of the internal mechanism of the utility model;

[0021] Figure 2 This is a schematic diagram of the internal top view structure of the utility model;

[0022] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along the AA direction;

[0023] Figure 4 This is a schematic diagram of the three-dimensional structure of the oil seal booster radial blade.

[0024] In the figure: 1. Oil seal inner baffle; 2. Oil seal inner ring groove; 3. Oil seal center baffle; 4. Oil seal booster radial blades; 5. Oil seal outer baffle; 6. Turbine rotor; 7. Bearing box; 8. Oil seal outer ring groove; 9. Oil return ring groove; 10. Oil return hole; 11. Arc groove. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the embodiments:

[0026] Example 1

[0027] like Figures 1-4 As shown, the utility model of an industrial steam turbine bearing box oil seal device includes an oil seal and a bearing box 7. The oil seal is sleeved on the outer periphery of the turbine rotor 6, and the bearing box 7 is sleeved on the outer periphery of the oil seal. The oil seal includes an oil seal inner baffle 1, an oil seal center baffle 3 and an oil seal outer baffle 5. The oil seal inner baffle 1, the oil seal center baffle 3 and the oil seal outer baffle 5 are arranged in sequence from the inside to the outside. A plurality of oil seal inner ring grooves 2 are arranged between the oil seal inner baffle 1 and the oil seal center baffle 3. A number of oil seal outer ring grooves 8 are arranged between the oil seal center baffle 3 and the oil seal outer baffle 5, and an oil seal booster radial blade 4 is arranged between the oil seal center baffle 3 and the oil seal outer ring groove 8. The bearing box 7 is placed between the oil seal inner baffle 1 and the oil seal outer baffle 5, and wrapped around the outer periphery of the oil seal center baffle 3, the oil seal inner ring groove 2 and the oil seal outer ring groove 8. A return oil ring groove 9 is arranged in the bearing box 7 corresponding to the oil seal center baffle 3, and an oil return hole 10 is arranged in the oil return ring groove 9 extending downward and outward.

[0028] like Figure 4 As shown, an arcuate groove 11 is provided axially on the oil seal boost radial blade 4, with the opening of the arcuate groove 11 facing the oil seal center baffle 3. The arcuate groove 11 on the oil seal boost radial blade 4, the oil seal center baffle 3 and the oil seal outer ring groove 8 form a vortex cavity.

[0029] The oil seal boost radial blades 4 have an interference fit with the oil seal outer ring groove 8. The oil seal has an interference fit with the turbine rotor 6. The size of the oil return ring groove 9 and the oil return hole 10 is proportional to the amount of lubricating oil leakage.

[0030] The inner wall of the bearing housing 7 is properly spaced from the oil seal. The clearances between the inner and outer walls of the bearing housing 7 and the inner baffle 1, center baffle 3, and outer baffle 5 of the oil seal are 0.5, 1, or 2 mm. The oil seal has four inner ring grooves 2 and two outer ring grooves 8.

[0031] Working process: The oil seal is sleeved on the outer periphery of the turbine rotor 6 and rotates with the turbine rotor 6. The bearing box 7 is placed on the outer periphery of the oil seal and the bearing box 7 does not rotate with the oil seal. When the oil seal rotates with the turbine rotor 6, the gap between the inner baffle 1 of the oil seal and the inner wall of the bearing box 7 is small, which prevents some lubricating oil from leaking. At the same time, centrifugal force throws some lubricating oil back into the bearing box 7, but some lubricating oil still leaks outward along the gap between the oil seal and the bearing box 7. This part of the leaked lubricating oil enters the labyrinth seal formed by the inner wall of the bearing box 7 in the inner ring groove 2 of the oil seal. After decompression, some of the leaked lubricating oil contacts the central baffle 3 of the oil seal and enters the oil return ring groove 9 of the bearing box 7. It then returns to the bearing box 7 through the oil return hole 10 of the bearing box 7. However, some lubricating oil still continues to leak out through the oil return ring groove 9 of the oil seal of the bearing box 7. After this part of the lubricating oil enters the oil seal booster radial blades 4, it is subjected to the centrifugal force and the action of the oil seal booster radial blades 4 to form a vortex, and the lubricating oil is thrown out axially. After encountering the oil seal center baffle 3, part of the lubricating oil is thrown by the center baffle to the oil return ring groove 9 of the bearing box 7 under the action of centrifugal force, and returns to the bearing box 7 through the oil return hole 10 of the bearing box 7; the remaining lubricating oil collides with the center baffle and returns to the oil seal booster radial blades 4 again. After multiple cycles, it returns to the bearing box 7 through the oil return hole 10 of the bearing box 7.

[0032] The description of the direction and relative position relationship of the structure in the present invention, such as the description of front, back, left, right, up and down, does not constitute a limitation of the present invention and is only for the convenience of description.

Claims

1. An industrial steam turbine bearing box oil seal device, characterized in that: The invention comprises an oil seal and a bearing box (7). The oil seal is sleeved on the outer periphery of the turbine rotor (6). The bearing box (7) is sleeved on the outer periphery of the oil seal. The oil seal comprises an inner oil seal baffle (1), a central oil seal baffle (3) and an outer oil seal baffle (5). The inner oil seal baffle (1), the central oil seal baffle (3) and the outer oil seal baffle (5) are arranged in sequence from the inside to the outside. A plurality of inner oil seal grooves (2) are arranged between the inner oil seal baffle (1) and the central oil seal baffle (3). A plurality of inner oil seal grooves (2) are arranged between the central oil seal baffle (3) and the outer oil seal baffle (5). A plurality of oil seal outer ring grooves (8) are arranged between the oil seal center baffle (3) and the oil seal outer ring groove (8); an oil seal booster radial blade (4) is arranged between the oil seal inner baffle (1) and the oil seal outer baffle (5); a bearing box (7) is placed between the oil seal inner baffle (1) and the oil seal outer baffle (5), and is wrapped around the outer periphery of the oil seal center baffle (3), the oil seal inner ring groove (2) and the oil seal outer ring groove (8); an oil return ring groove (9) is arranged in the bearing box (7) corresponding to the oil seal center baffle (3); and an oil return hole (10) is arranged in the oil return ring groove (9) extending downward and outward.

2. The industrial steam turbine bearing box oil seal device according to claim 1, characterized in that: The arc-shaped groove (11) on the oil seal booster radial blade (4), the oil seal center baffle (3) and the oil seal outer ring groove (8) form a vortex cavity.

3. The industrial steam turbine bearing box oil seal device according to claim 2, characterized in that: The oil seal booster radial blades (4) are interference fit with the oil seal outer ring groove (8).

4. The industrial steam turbine bearing box oil seal device according to claim 3, characterized in that: The oil seal is interference fit with the turbine rotor (6).

5. The industrial steam turbine bearing box oil seal device according to claim 4, characterized in that: The sizes of the oil return ring groove (9) and the oil return hole (10) are proportional to the amount of lubricating oil leakage.

6. The industrial steam turbine bearing box oil seal device according to any one of claims 1 to 5, characterized in that: The inner wall of the bearing box (7) is clearance-matched with the oil seal.

7. The industrial steam turbine bearing box oil seal device according to claim 6, characterized in that: The gap between the inner wall of the bearing box (7) and the oil seal is 0.5-2 mm.

8. The industrial steam turbine bearing box oil seal device according to claim 7, characterized in that: The number of the oil seal inner ring grooves (2) is at least four.

9. The industrial steam turbine bearing box oil seal device according to claim 8, characterized in that: The number of the oil seal outer ring grooves (8) is at least two.

Images