Oil mist leakage-proof bearing sealing structure of hydroelectric generator

Abstract

The utility model discloses a kind of oil mist leakage-preventing hydroelectric generator bearing sealing structure, it is related to hydroelectric generator bearing sealing technical field, solve the problem of insufficient sealing reliability, oil return is not smooth and differential pressure imbalance exacerbates leakage in prior art, the structure includes bearing box, sealing seat and differential pressure balancing device, sealing seat is fixed in bearing box by connecting flange, its inner wall is integrated from outside to inside labyrinth seal and contact type seal piece;Labyrinth seal contains sealing tooth, sealing chamber, confluence passage, sealing seat is equipped with oil return passage, confluence passage is communicated with oil return passage, the utility model is through the multistage collaborative design of labyrinth seal and contact type seal piece, realize the double sealing protection effect of throttling condensation and contact block, effectively block oil mist leakage, avoid running, dripping phenomenon, and adopt the cooperation of confluence passage and oil return passage and sealing chamber, make oil recovery high efficiency smooth, avoid oil accumulation and loss.

Description

Technical Field

[0001] This utility model relates to the field of hydro-generator bearing sealing, and in particular to a hydro-generator bearing sealing structure that prevents oil mist leakage. Background Technology

[0002] When a hydro-generator is running, the bearings generate a lot of heat due to high-speed rotation and friction, which causes the temperature inside the bearing housing to rise. The lubricating oil evaporates and forms oil mist. At the same time, the internal air pressure rises, creating a pressure difference that drives the oil mist to leak outward.

[0003] Existing sealing technologies often employ a single sealing method, such as labyrinth seals or single sealing rings. This approach is prone to the following problems: insufficient sealing reliability, as a single sealing structure cannot effectively block oil mist, and under high temperature and pressure conditions, oil mist can easily seep out from the sealing gap, resulting in "running, leaking, and dripping" phenomena; or oil accumulation and poor return flow, as the tooth shape and chamber design of traditional labyrinth seals are unreasonable, and condensed oil can easily accumulate in the sealing cavity, failing to automatically return to the bearing housing, and instead seeping outward under the action of pressure difference. The pressure difference imbalance exacerbates leakage, and the internal air pressure fluctuations of the bearing housing cannot be balanced in time. The internal positive pressure forces the oil mist to force through the sealing interface, causing continuous leakage.

[0004] The above-mentioned problems not only lead to lubricating oil loss and affect the lubrication effect of the bearing, but may also introduce external moisture and dust, causing lubricating oil emulsification and bearing wear, shortening the equipment life and increasing maintenance costs. Therefore, this utility model provides a sealing structure for hydro-generator bearings that prevents oil mist leakage. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this utility model provides a sealing structure for a hydro-generator bearing that prevents oil mist leakage, thus solving the problems mentioned in the background section.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution: a sealing structure for a hydro-generator bearing that prevents oil mist leakage, including a bearing housing, a sealing seat installed inside the bearing end cover of the bearing housing and sleeved on the hydro-generator shaft, and a differential pressure balancing device on the top of the bearing housing. The inner wall of the sealing seat is provided with a labyrinth seal and a contact seal in sequence from the outside to the inside. The contact seal and the labyrinth seal are integral with the sealing seat. The labyrinth seal consists of multiple sealing teeth and a sealing chamber formed between the multiple sealing teeth; A confluence channel is provided between the multiple sealing chambers and at the bottom of the sealing teeth. An oil return channel is also provided on the end face of the sealing seat. The oil return channel extends to and communicates with a sealing chamber located away from the contact seal. The contact seal is in close contact with the journal of the turbine generator shaft.

[0007] As a further technical solution of this utility model, the confluence channel is connected to the sealed chamber, and the oil return channel is connected to the sealed chamber; The return oil channel and the manifold channel are both inclined and interconnected. The inclined end of the manifold channel faces the return oil channel, and the inclined end of the return oil channel is inclined towards the inside of the bearing housing.

[0008] As a further technical solution of this utility model, the angle of inclination of the sealing tooth to the horizontal plane is 5°-15°.

[0009] As a further technical solution of this utility model, the sealing tooth has 4-6 teeth, and the gap between adjacent teeth is 0.2-0.5mm, forming a tortuous throttling channel.

[0010] As a further technical solution of this utility model, the contact seal is a lip seal ring made of rubber or polytetrafluoroethylene, and the inner side of the contact seal is provided with a lubricating coating, which is a polytetrafluoroethylene lubricating coating.

[0011] As a further technical solution of this utility model, the differential pressure balancing device is a spring-loaded one-way valve, whose opening pressure threshold matches the safe differential pressure inside the bearing housing, and the safe differential pressure is ≤0.1kPa.

[0012] As a further technical solution of this utility model, the sealing seat is also integrally provided with a connecting flange on the outside, and the sealing seat is installed on the bearing housing by the connecting flange and bolts.

[0013] This utility model provides a sealing structure for a hydro-generator bearing that prevents oil mist leakage, and has the following advantages compared with the prior art: 1. This design provides a sealing structure for the bearing of a hydro-generator that prevents oil mist leakage. Through the multi-stage collaborative design of labyrinth seals and contact seals, it achieves a dual sealing protection effect of throttling condensation and contact blocking, effectively blocking oil mist leakage and avoiding run-in and dripping phenomena. This not only extends the equipment life and reduces maintenance costs, but also reduces lubricating oil loss and pollution, avoids bearing wear and lubricating oil emulsification, and reduces equipment maintenance frequency and costs.

[0014] 2. The oil mist leakage prevention bearing sealing structure of the hydro-generator designed in this paper adopts the cooperation of the confluence channel and the return oil channel with the sealing chamber to make the oil recovery efficient and smooth. Moreover, the inclined sealing teeth of the labyrinth seal, the confluence channel and the return oil channel constitute a directional drainage and recovery mechanism. The condensed oil automatically flows back to the bearing box by gravity, avoiding oil accumulation and loss. Attached Figure Description

[0015] Figure 1 A schematic diagram of a sealing structure for a hydro-generator bearing to prevent oil mist leakage; Figure 2 A cross-sectional view of a sealing structure for a hydro-generator bearing that prevents oil mist leakage; Figure 3 for Figure 2 The front view.

[0016] In the diagram: 1. Sealing seat; 11. Sealing teeth; 12. Sealing chamber; 13. Manifold; 14. Oil return passage; 2. Contact seal; 3. Labyrinth seal; 4. Connecting flange. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0018] Please see Figure 1-3 This utility model provides a technical solution for a sealing structure for a hydro-generator bearing to prevent oil mist leakage: a sealing structure for a hydro-generator bearing to prevent oil mist leakage includes a bearing housing, a sealing seat 1 installed inside the bearing end cover of the bearing housing and sleeved on the hydro-generator shaft, and a pressure differential balancing device on the top of the bearing housing. The sealing seat 1 is also integrally provided with a connecting flange 4, and the sealing seat 1 is installed on the bearing housing through the connecting flange 4 and bolts to ensure a tight seal between the sealing seat 1 and the bearing housing. The pressure differential balancing device is a spring-loaded one-way valve, whose opening pressure threshold matches the safe pressure differential inside the bearing housing. The safe pressure differential is ≤0.1kPa, which can dynamically balance the air pressure inside the bearing housing and the external environment, eliminating the driving force for oil mist leakage. The inner wall of the sealing seat 1 is equipped with a labyrinth seal 3 and a contact seal 2 from the outside to the inside. The contact seal 2 and the labyrinth seal 3 are integrated with the sealing seat 1 as a whole, which avoids the risk of leakage caused by assembly gaps and improves the integrity and sealing performance of the sealing system.

[0019] The labyrinth seal 3 consists of multiple sealing teeth 11 and a sealing chamber 12 formed between the multiple sealing teeth 11. The angle of inclination of the sealing teeth 11 to the horizontal plane is 5°-15°. The number of teeth of the sealing teeth 11 is 4-6, and the gap between adjacent teeth is 0.2-0.5mm, forming a tortuous throttling channel. The throttling channel is connected to the sealing chamber 12. A confluence channel 13 is opened between the multiple sealing chambers 12 and at the bottom of the sealing teeth 11. A return oil channel 14 is also opened on the end face of the sealing seat 1. The return oil channel 14 extends into a sealing chamber 12 away from the contact seal 2 and is connected to it. The confluence channel 13 is connected to the sealing chamber 12, and the return oil channel 14 is connected to the sealing chamber 12. The return oil channel 14 and the confluence channel 13 are both inclined and connected to each other. The inclined end of the confluence channel 13 faces the return oil channel 14, and the inclined end of the return oil channel 14 is inclined towards the inside of the bearing housing to ensure smooth return of condensed oil. The contact seal 2 is in close contact with the journal of the turbine generator shaft. The contact seal 2 is a lip seal ring made of rubber or polytetrafluoroethylene. Its lip fits tightly with the journal of the turbine generator shaft to achieve a flexible seal. The inner side of the contact seal 2 is provided with a lubricating coating, which is a polytetrafluoroethylene lubricating coating. This ensures the sealing effect and reduces frictional wear with the shaft.

[0020] The working principle of this utility model is as follows: When in use, the opening pressure threshold of the spring-loaded check valve can be set to 0.1 kPa. When the hydro-generator is running, the bearing rotates at high speed and generates heat through friction. The temperature inside the bearing housing rises, the lubricating oil evaporates to form oil mist, and when the internal air pressure rises to 0.1 kPa, the spring-loaded check valve automatically opens to release the internal positive pressure. When the internal air pressure decreases, the check valve closes to prevent external water vapor and dust from entering the bearing housing. After the oil mist is generated, it first enters the tortuous throttling channel of the labyrinth seal 3. During the multiple expansion and contraction processes, the kinetic energy is consumed, the flow rate decreases and condenses into droplets. Under the action of gravity, the droplets flow into the sealing chamber 12 along the inclined sealing tooth 11 surface. Then, they are collected by the confluence channel 13 at the bottom and flow back to the oil return channel 14, eventually flowing back into the bearing housing. The remaining uncondensed trace amount of oil mist continues to move and is completely blocked by the contact seal 2, preventing it from leaking outward. The technical principle of this utility model is based on fluid mechanics, thermodynamics and mechanical sealing theory. The throttling and condensation principle of the labyrinth seal 3 realizes the initial treatment of oil mist, while the combination of the confluence channel 13 and the return oil channel 14 adopts the gravity return principle of directional flow to realize oil recovery. The blocking principle of the contact seal 2 realizes zero leakage protection, and the pressure difference balance principle eliminates the leakage driving force. The synergy of multiple principles ensures the anti-leakage effect.

[0021] The above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model are implemented according to conventional methods in the art, unless otherwise specified or limited.

Claims

1. A sealing structure for a hydro-generator bearing to prevent oil mist leakage, comprising a bearing housing, characterized in that, It also includes a sealing seat (1) installed inside the bearing end cover of the bearing housing and sleeved on the turbine generator shaft, and a differential pressure balancing device on the top of the bearing housing; The inner wall of the sealing seat (1) is provided with a labyrinth seal (3) and a contact seal (2), and the contact seal (2) and the labyrinth seal (3) are integral with the sealing seat (1). The labyrinth seal (3) consists of multiple sealing teeth (11) and a sealing chamber (12) formed between the multiple sealing teeth (11); A confluence channel (13) is provided between the multiple sealing chambers (12) and at the bottom of the sealing tooth (11). A return oil channel (14) is also provided on the end face of the sealing seat (1). The return oil channel (14) extends into a sealing chamber (12) away from the contact seal (2) and is connected to it.

2. The sealing structure for a hydro-generator bearing to prevent oil mist leakage according to claim 1, characterized in that, The manifold (13) is connected to the sealed chamber (12), and the oil return channel (14) is connected to the sealed chamber (12); The return oil channel (14) and the confluence channel (13) are both inclined and interconnected. The inclined end of the confluence channel (13) faces the return oil channel (14), and the inclined end of the return oil channel (14) is inclined towards the inside of the bearing housing.

3. The sealing structure for a hydro-generator bearing to prevent oil mist leakage according to claim 1, characterized in that, The angle of inclination of the sealing tooth (11) to the horizontal plane is 5°-15°.

4. The sealing structure for a hydro-generator bearing to prevent oil mist leakage according to claim 1, characterized in that, The contact seal (2) is a lip seal ring made of rubber or polytetrafluoroethylene, which is in close contact with the journal of the turbine generator shaft. The inner side of the contact seal (2) is provided with a lubricating coating, which is a polytetrafluoroethylene lubricating coating.

5. The sealing structure for a hydro-generator bearing to prevent oil mist leakage according to claim 1, characterized in that, The differential pressure balancing device is a spring-loaded check valve, whose opening pressure threshold is matched with the safe differential pressure inside the bearing housing.

6. The sealing structure for a hydro-generator bearing to prevent oil mist leakage according to claim 1, characterized in that, The sealing seat (1) is also integrally provided with a connecting flange (4) on the outside, and the sealing seat (1) is installed on the bearing housing by the connecting flange (4) and bolts.

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