Industrial steam turbine bearing box oil seal device

Abstract

The present application relates to the technical field of sealing device, especially 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, the oil seal inner baffle, the oil seal center baffle and the oil seal outer baffle are sequentially arranged from inside to 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, oil seal supercharging radial blades are arranged between the oil seal center baffle and the oil seal outer ring grooves, the bearing box is arranged 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 grooves and the oil seal outer ring grooves, an oil return ring groove is arranged in the bearing box corresponding to the oil seal center baffle, and the oil return ring groove extends downward and outward to set an oil return hole, the present application improves the sealing effect of the turbine bearing box, prevents lubricating oil leakage and guarantees the safe operation of the equipment.

Description

Technical Field

[0001] This invention relates to the field of sealing device technology, and in particular to an oil seal device for an industrial steam turbine bearing housing. Background Technology

[0002] In the chemical industry, especially in large-scale refining and chemical enterprises, industrial steam turbines are widely used to reduce energy loss, save energy, meet the gas parameter requirements of production processes, and achieve steam network balance. As a key sealing component of the turbine bearing housing, the oil seal assembly of the industrial steam turbine bearing housing has a significant impact on the normal operation of the equipment and the safe production of the plant.

[0003] When the turbine is operating, the rotor's disturbance causes lubricating oil in the bearing housing to splash, resulting in leakage along the gap between the rotor and the bearing housing. Traditional bearing housing oil seals often use labyrinth seals, which are formed by machining concave and convex annular grooves on the oil seal assembly and adjusting the radial clearance with the bearing housing seal. The splashed lubricating oil in the bearing housing is depressurized step by step through the concave and convex annular grooves and the bearing housing gap, achieving the effect of sealing the lubricating oil. This sealing method has certain drawbacks. First, it requires a high radial clearance from the sealing assembly. During equipment operation, thermal expansion and bearing housing deformation can cause changes in the sealing clearance, reducing the sealing effect and causing lubricating oil leakage. Second, this type of seal is a non-contact passive seal, making it very difficult to achieve a completely leak-free operation. Leaked lubricating oil accumulates outside the bearing housing, especially near the turbine side, where it can accumulate in the turbine insulation material. When exposed to high temperatures, it vaporizes, producing oil fumes. Large leaks can easily cause fires, posing a safety hazard. Summary of the Invention

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

[0005] This invention provides an oil seal device for an industrial steam turbine bearing housing, comprising an oil seal and a bearing housing. The oil seal is sleeved on the outer periphery of the turbine rotor, and the bearing housing is sleeved on the outer periphery of the oil seal. The oil seal includes an inner baffle, a central baffle, and an outer baffle, arranged sequentially from the inside to the outside. A plurality of inner annular grooves are provided between the inner baffle and the central baffle, and a plurality of outer annular grooves are provided between the central baffle and the outer baffle. A pressure-boosting radial blade is provided between the central baffle and the outer annular grooves. The bearing housing is placed between the inner baffle and the outer baffle and is wrapped around the outer periphery of the central baffle, the inner annular grooves, and the outer annular grooves. A return oil annular groove is provided inside the bearing housing corresponding to the central baffle, and a return oil hole extends downward and outward from the return oil annular groove.

[0006] The oil seal is fitted around the outer circumference of the turbine rotor and rotates with it. The bearing housing is located around the outer circumference of the oil seal and does not rotate with it. When the oil seal rotates with the turbine rotor, the small gap between the inner baffle of the oil seal and the inner wall of the bearing housing prevents some lubricating oil from leaking out. At the same time, centrifugal force throws some lubricating oil back into the bearing housing. However, 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 annular groove of the oil seal and the inner wall of the bearing housing. After pressure reduction, some of the leaked lubricating oil contacts the central baffle of the oil seal and enters the oil return annular groove of the bearing housing oil seal, returning to the bearing housing through the oil return hole of the bearing housing oil seal. However, some lubricating oil still leaks outward through the oil return ring groove of the bearing housing oil seal. After this part of the lubricating oil enters the oil seal pressure-boosting radial blade, it forms a vortex under the action of centrifugal force and the oil seal pressure-boosting radial blade. The lubricating oil is thrown out axially. After encountering the oil seal center baffle, some of the lubricating oil is thrown from the center baffle to the oil return ring groove of the bearing housing oil seal under the action of centrifugal force, and returns to the bearing housing through the oil return hole of the bearing housing oil seal. The remaining lubricating oil returns to the oil seal pressure-boosting radial blade after colliding with the center baffle. After multiple cycles, it returns to the bearing housing through the oil return hole of the bearing housing oil seal.

[0007] The oil seal booster radial blades are provided with arc-shaped grooves along the axial direction, with the opening of the arc-shaped grooves facing the center baffle of the oil seal. After the lubricating oil enters the oil seal booster radial blades, due to the presence of gas, it forms a vortex in the arc-shaped grooves under the action of centrifugal force and the oil seal booster radial blades. During the continuous rotation of the oil seal booster radial blades, a local high-pressure zone is formed in the arc-shaped grooves. Because the outer ring groove of the oil seal forms a labyrinth seal with the inner wall of the bearing housing, it has a throttling effect. The gas in the high-pressure zone prevents the lubricating oil from continuing to leak outwards and accelerates the leakage of lubricating oil back to the bearing housing through the return oil ring groove and the return oil hole.

[0008] The arc-shaped groove on the radial blade of the oil seal pressure booster forms a vortex cavity with the oil seal center baffle and the oil seal outer ring groove. Under the action of centrifugal force, the lubricating oil forms a vortex motion within the vortex cavity and between the oil seal center baffle, thereby continuously increasing the pressure of the lubricating oil.

[0009] The aforementioned oil seal pressure boosting radial blades are interference-fitted with the outer annular groove of the oil seal. This ensures that the lubricating oil in the vortex cavity forms high-pressure oil under the action of centrifugal force.

[0010] The oil seal is interference-fitted with the turbine rotor. By interfering with the turbine rotor, the oil seal rotates synchronously with the turbine rotor, eliminating the need for external power to drive the oil seal's rotation.

[0011] The dimensions of the oil return ring groove and oil return hole are directly proportional to the amount of lubricating oil leakage. Through calculation and experimentation, the amount of lubricating oil leakage is determined, thereby determining the dimensions of the oil return ring groove and oil return hole to ensure that leaked lubricating oil smoothly returns to the bearing housing.

[0012] The inner wall of the bearing housing is fitted with the oil seal with a clearance fit. This design provides a non-contact seal, resulting in wear-free operation, requiring no special maintenance, and extending service life.

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

[0014] The number of inner annular grooves in the oil seal is at least four. This forms a multi-stage pressure reduction system to prevent lubricating oil leakage.

[0015] The number of outer annular grooves of the oil seal is at least two. This forms a multi-stage pressure reduction system to prevent lubricating oil leakage.

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

[0017] 1. This invention prevents partial lubricant leakage by setting an inner baffle, a central baffle, and an outer baffle of the oil seal. The inner and outer annular grooves of the oil seal, forming a labyrinth seal with the inner wall of the bearing housing, reduce pressure and prevent further lubricant leakage. The pressure-boosting radial blades of the oil seal create a vortex under centrifugal force, causing the lubricant to be axially thrown out. Upon encountering the central baffle, some lubricant is thrown by centrifugal force to the oil return annular groove of the bearing housing oil seal, further preventing lubricant leakage. The oil return annular groove and return hole enable the recovery of leaked oil, avoiding waste.

[0018] 2. An arc-shaped groove is provided along the axial direction on the radial blade of the oil seal pressure booster, with the opening of the arc-shaped groove opposite to the center baffle of the oil seal. After the lubricating oil enters the radial blade of the oil seal pressure booster, due to the presence of gas, it forms a vortex in the arc-shaped groove under the action of centrifugal force and the radial blade of the oil seal pressure booster. During the continuous rotation of the radial blade of the oil seal pressure booster, a local high-pressure zone will be formed in the arc-shaped groove. Because the outer ring groove of the oil seal forms a labyrinth seal with the inner wall of the bearing housing, it has a throttling effect. The gas in the high-pressure zone prevents the lubricating oil from continuing to leak outward and accelerates the leakage of lubricating oil back to the bearing housing through the return oil ring groove and the return oil hole.

[0019] 3. The bearing housing inner wall and the oil seal are fitted with a clearance fit. This design provides a non-contact seal, resulting in wear-free operation, requiring no special maintenance, and extending service life. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the internal mechanism of the present invention;

[0021] Figure 2 This is a top view of the internal structure of the present invention;

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

[0023] Figure 4 A three-dimensional structural diagram of the radial blade for oil seal pressurization.

[0024] In the diagram: 1. Inner baffle of oil seal; 2. Inner annular groove of oil seal; 3. Center baffle of oil seal; 4. Radial blade of oil seal booster; 5. Outer baffle of oil seal; 6. Turbine rotor; 7. Bearing housing; 8. Outer annular groove of oil seal; 9. Oil return annular groove; 10. Oil return hole; 11. Arc-shaped groove. Detailed Implementation

[0025] The present invention will be further described below with reference to embodiments:

[0026] Example 1

[0027] like Figures 1-4 As shown, the present invention discloses an oil seal device for an industrial turbine bearing housing, comprising an oil seal and a bearing housing 7. The oil seal is sleeved on the outer periphery of the turbine rotor 6, and the bearing housing 7 is sleeved on the outer periphery of the oil seal. The oil seal includes an inner baffle 1, a central baffle 3, and an outer baffle 5, arranged sequentially from the inside to the outside. A plurality of inner annular grooves 2 are provided between the inner baffle 1 and the central baffle 3, and a plurality of outer annular grooves 8 are provided between the central baffle 3 and the outer baffle 5. An oil seal pressurizing radial blade 4 is provided between the central baffle 3 and the outer annular grooves 8. The bearing housing 7 is placed between the inner baffle 1 and the outer baffle 5 and is wrapped around the outer periphery of the central baffle 3, the inner annular grooves 2, and the outer annular grooves 8. A return oil annular groove 9 is provided inside the bearing housing 7 corresponding to the central baffle 3, and a return oil hole 10 extends downward and outward from the return oil annular groove 9.

[0028] like Figure 4 As shown, an arc-shaped groove 11 is provided along the axial direction on the oil seal booster radial blade 4, and the opening of the arc-shaped groove 11 is opposite to the oil seal center baffle 3. The arc-shaped groove on the oil seal booster radial blade, together with the oil seal center baffle and the oil seal outer ring groove, forms a vortex cavity.

[0029] The oil seal's booster radial blades are interference-fitted with the outer annular groove of the oil seal. The oil seal is also interference-fitted with the turbine rotor. The dimensions of the return oil annular groove and return oil hole are directly proportional to the amount of lubricating oil leakage.

[0030] The inner wall of the bearing housing 7 is clearance-fitted with the oil seal. Specifically, 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. There are four inner annular grooves 2 and two outer annular grooves 8 in the oil seal.

[0031] Working process: The oil seal is fitted around the outer circumference of the turbine rotor 6 and rotates with the turbine rotor 6. The bearing housing 7 is placed around the outer circumference of the oil seal and does not rotate with the oil seal. When the oil seal rotates with the turbine rotor 6, due to the small gap between the inner baffle 1 of the oil seal and the inner wall of the bearing housing 7, some lubricating oil leakage is prevented. At the same time, centrifugal force throws some lubricating oil back into the bearing housing 7, but some lubricating oil still leaks outward along the gap between the oil seal and the bearing housing 7. This leaked lubricating oil enters the labyrinth seal formed by the inner ring groove 2 of the oil seal and the inner wall of the bearing housing 7. 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 oil seal in the bearing housing 7, and returns to the bearing housing 7 through the oil return hole 10 of the oil seal. However, some lubricating oil still leaks outward through the oil seal return ring groove 9 of the bearing housing 7. After this part of the lubricating oil enters the oil seal pressure boosting radial blade 4, it forms a vortex under the action of centrifugal force and the oil seal pressure boosting radial blade 4. The lubricating oil is thrown out axially. After encountering the oil seal center baffle 3, some of the lubricating oil is thrown from the center baffle to the oil seal return ring groove 9 of the bearing housing 7 under the action of centrifugal force, and returns to the bearing housing 7 through the oil seal return hole 10. The remaining lubricating oil returns to the oil seal pressure boosting radial blade 4 again after colliding with the center baffle. After multiple cycles, it returns to the bearing housing 7 through the oil seal return hole 10.

[0032] The descriptions of the orientation and relative positional relationships of the structures in this invention, such as front, back, left, right, up, and down, do not constitute a limitation of this invention, but are merely for the convenience of description.

Claims

1. An oil seal device for an industrial steam turbine bearing housing, characterized in that, The assembly includes an oil seal and a bearing housing (7). The oil seal is fitted around the outer periphery of the turbine rotor (6), and the bearing housing (7) is fitted around the outer periphery of the oil seal. The oil seal includes an inner baffle (1), a center baffle (3), and an outer baffle (5). The inner baffle (1), center baffle (3), and outer baffle (5) are arranged sequentially from the inside to the outside. Several inner annular grooves (2) are provided between the inner baffle (1) and the center baffle (3). Several oil seal outer ring grooves (8) are provided between the oil seal center baffle (3) and the oil seal outer ring groove (8). The oil seal pressurizing radial blade (4) is provided between the oil seal center baffle (3) and the oil seal outer ring groove (8). The bearing housing (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). The bearing housing (7) is provided with an oil return ring groove (9) corresponding to the oil seal center baffle (3). The oil return ring groove (9) extends downward and outward to provide an oil return hole (10).

2. The industrial steam turbine bearing housing oil seal device according to claim 1, characterized in that, An arc-shaped groove (11) is provided along the axial direction on the oil seal booster radial blade (4), and the opening of the arc-shaped groove (11) is opposite to the oil seal center baffle (3).

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

4. The industrial steam turbine bearing housing oil seal device according to claim 3, characterized in that, The oil seal booster radial blade (4) is interference-fitted with the oil seal outer ring groove (8).

5. The industrial steam turbine bearing housing oil seal device according to claim 4, characterized in that, The oil seal is interference-fitted with the turbine rotor (6).

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

7. The industrial steam turbine bearing housing oil seal device according to any one of claims 1-6, characterized in that, The inner wall of the bearing housing (7) is fitted with the oil seal with a clearance fit.

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

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

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

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