Bearing sealing protection structure of LNG booster pump
The bearing seal protection structure for LNG pumps addresses the issue of bearing failure by containing low-temperature gas, enhancing bearing longevity and reducing maintenance through a sealed transition sleeve.
Patent Information
- Application Number
- CN202422179535.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-05
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-09-05
AI Technical Summary
The bearings of LNG booster pumps are prone to damage in low temperature environments, resulting in short service life and affecting working efficiency.
A bearing seal protection structure is designed. By setting a rotor sleeve on the outside of the rotor, the sealing member and the rotor sleeve are designed to avoid direct contact with the bearing by low-temperature gas, forming a seal protection.
Effectively protect the working environment of bearings in low temperature environments, avoid too low temperatures, extend the bearing life, and ensure the normal operation of the booster pump.
Smart Images
Figure CN223104848U_ABST
Abstract
Description
Technical Field:
[0001] The utility model relates to the technical field of LNG storage tank pressurization, in particular to a bearing sealing and protecting structure of an LNG booster pump. Background Art:
[0002] At present, when an LNG storage tank is in use, as the liquid in the tank is used, the liquid level in the tank continuously drops, the gas phase space increases, the pressure in the LNG storage tank continuously decreases, and the liquid outflow speed decreases until it stops. Therefore, during normal operation, gas must be continuously supplemented into the tank to maintain the pressure in the tank within a certain range, and this process is called pressurization. Currently, a booster pump is generally required to increase the gas pressure. However, since the temperature of LNG gas is as low as about -130°C, when an ordinary booster pump pressurizes such low-temperature gas, some low-temperature gas or liquid will inevitably leak into the motor cavity. Due to the large space in the motor cavity, new low-temperature gas will enter before the low-temperature gas that has entered has time to heat up. After the low-temperature gas accumulates, the temperature in the motor cavity will be greatly reduced. Since the bearing supporting the rotor has no special protection measures and the bearing directly contacts the low-temperature gas, and the bearing is an easily damaged component, the bearing will fail when working in a low-temperature environment, the bearing life is short, and once the bearing fails, the entire booster pump cannot work, and the bearing needs to be replaced by frequent shutdown and maintenance, which affects the work efficiency.
[0003] In summary, the problem of damage and failure of the bearing in the LNG booster pump when working in a low-temperature environment has become a technical problem that urgently needs to be solved in the industry. Content of the Utility Model:
[0004] The utility model provides a bearing sealing and protecting structure of an LNG booster pump to make up for the deficiencies of the prior art and solve the problem that the bearing in the conventional LNG booster pump is directly in contact with low-temperature gas and easily causes bearing failure.
[0005] The technical solution adopted by the utility model to solve the above technical problems is as follows:
[0006] A bearing sealing and protecting structure of an LNG booster pump includes a housing. A stator and a rotor are arranged inside the housing. An end cover is arranged at the end of the housing. A volute is installed outside the end cover. An impeller is arranged inside the volute. The rotor passes through the end cover and is connected to the impeller. An air inlet and an air outlet are arranged on the volute. A rotor shaft sleeve is arranged outside the rotor. One end of the rotor shaft sleeve is closed, and the other end is provided with a flange. The closed end of the rotor shaft sleeve is fixedly connected to the housing. The flange of the rotor shaft sleeve and the end cover are fixedly connected by bolts. A first bearing is arranged inside the closed end of the rotor shaft sleeve and is used to support one end of the rotor. A second bearing for supporting the other end of the rotor is arranged inside the end cover. A seal is arranged between the end cover and the rotor to isolate the second bearing from the impeller.
[0007] The thickness of the rotor shaft sleeve between the stator and the rotor is less than the thickness of the rotor shaft sleeve at the first bearing and the flange.
[0008] The thickness of the rotor shaft sleeve between the stator and the rotor does not exceed 1 mm.
[0009] The stator and the rotor shaft sleeve are in contact and fit, and there is a gap between the rotor and the rotor shaft sleeve.
[0010] The closed end of the rotor shaft sleeve is connected with the housing by interference press-fitting.
[0011] The rotor shaft sleeve is made of stainless steel.
[0012] A sealing ring is provided between the flange and the end cover.
[0013] The seal is fixed in the groove of the end cover, and there is a clearance fit between the rotor and the seal.
[0014] The utility model adopts the above scheme and has the following advantages:
[0015] By providing a rotor shaft sleeve outside the rotor, the rotor shaft sleeve covers the first bearing and the second bearing inside, reducing the space volume where the first bearing and the second bearing are located. When part of the low-temperature gas in the volute leaks from the gap between the seal and the rotor into the rotor shaft sleeve, since the amount of low-temperature gas leaking from the gap is very small, the low-temperature gas will instantly expand into high-temperature gas. Because the volume of the rotor shaft sleeve is small and the whole is sealed, the gas quickly fills the entire rotor shaft sleeve and will not leak into the motor cavity again. Moreover, the gas pressure in the rotor shaft sleeve gradually increases, and the low-temperature gas in the volute cannot continue to leak into the rotor shaft sleeve, avoiding the temperature in the rotor shaft sleeve from being too low, ensuring the working environment of the first bearing and the second bearing, preventing the bearing from failing, and ensuring the bearing life. BRIEF DESCRIPTION OF THE DRAWINGS:
[0016] Figure 1 It is a schematic cross-sectional structure diagram of the utility model.
[0017] Figure 2 It is a schematic structure diagram of the rotor shaft sleeve of the utility model.
[0018] In the figure, 1. housing, 2. stator, 3. rotor, 4. end cover, 5. volute, 6. impeller, 7. air inlet, 8. air outlet, 9. rotor shaft sleeve, 10. flange, 11. first bearing, 12. second bearing, 13. seal, 14. sealing ring. DETAILED DESCRIPTION OF THE EMBODIMENTS:
[0019] To clearly illustrate the technical features of the solution, the utility model will be described in detail below through specific embodiments and in conjunction with its drawings.
[0020] AsFigure 1-2 As shown in the figure, a bearing seal protection structure for an LNG booster pump includes a housing 1. Inside the housing 1, there is a stator 2 and a rotor 3. At the end of the housing 1, there is an end cover 4. A volute 5 is installed outside the end cover 4. Inside the volute 5, there is an impeller 6. The rotor 3 passes through the end cover 4 and is connected to the impeller 6. The volute 5 is provided with an air inlet 7 and an air outlet 8. Outside the rotor 3, there is a rotor shaft sleeve 9. One end of the rotor shaft sleeve 9 is closed, and the other end is provided with a flange 10. The closed end of the rotor shaft sleeve 9 is fixedly connected to the housing 1. The flange 10 of the rotor shaft sleeve 9 is fixedly connected to the end cover 4 by bolts. Inside the closed end of the rotor shaft sleeve 9, there is a first bearing 11, which is used to support one end of the rotor 3. Inside the end cover 4, there is a second bearing 12 used to support the other end of the rotor 3. Between the end cover 4 and the rotor 3, there is a seal 13 used to isolate the second bearing 12 from the impeller 6.
[0021] The thickness of the rotor shaft sleeve 9 between the stator 2 and the rotor 3 is less than the thickness of the rotor shaft sleeve 9 at the first bearing 11 and the flange 10. The thicker thickness of the rotor shaft sleeve 9 at the first bearing 11 is beneficial to improving the strength and can better install and support the first bearing 11. The thickness of the rotor shaft sleeve 9 at the flange 10 is also thicker, which can improve the connection strength between the flange 10 and the end cover 4.
[0022] The thickness of the rotor shaft sleeve 9 between the stator 2 and the rotor 3 does not exceed 1 mm and will not interfere with the normal rotation of the rotor 3.
[0023] The stator 2 and the rotor shaft sleeve 9 are in contact and fit, and the rotor shaft sleeve 9 can support the stator 2. There is a gap between the rotor 3 and the rotor shaft sleeve 9, which will not affect the normal rotation of the rotor 3.
[0024] The closed end of the rotor shaft sleeve 9 and the housing 1 are connected by interference press-fitting.
[0025] The rotor shaft sleeve 9 is made of 304 stainless steel, which has good corrosion resistance, low-temperature strength and mechanical properties.
[0026] A sealing ring 14 is provided between the flange 10 and the end cover 4 to prevent the gas inside the rotor shaft sleeve 9 from leaking from between the flange 10 and the end cover 4 to the motor cavity.
[0027] The seal 13 is fixed in the groove of the end cover 4. The rotor 3 and the seal 13 are in clearance fit to form a clearance seal, and a very small amount of gas can pass through between the rotor 3 and the seal 13.
[0028] Working principle:
[0029] After startup, the rotor 3 rotates at high speed. The rotor 3 drives the impeller 6 to rotate at high speed. The low-temperature gas enters the volute 5 from the air inlet 7 for pressurization and is discharged outward from the air outlet 8. During the pressurization process of the low-temperature gas in the volute 5, part of the low-temperature gas will leak into the rotor shaft sleeve 9 through the gap between the seal 13 and the rotor 3. Since the amount of low-temperature gas leaking from the gap is very small, the low-temperature gas will instantly expand into high-temperature gas after entering the rotor shaft sleeve 9. Since the rotor shaft sleeve 9 is small in volume and integrally sealed, the gas quickly fills the entire rotor shaft sleeve 9 and will not leak into the motor cavity anymore. Moreover, the gas pressure in the rotor shaft sleeve 9 gradually increases, and the low-temperature gas in the volute 5 cannot continue to leak into the rotor shaft sleeve 9, thus avoiding the temperature in the rotor shaft sleeve 9 from being too low, ensuring the working environment of the first bearing 11 and the second bearing 12, and playing a role in sealing and protecting the first bearing 11 and the second bearing 12.
[0030] The above specific implementation manners cannot be used as a limitation to the protection scope of the present utility model. For those skilled in the art of this technology, any alternative improvement or transformation made to the implementation manners of the present utility model falls within the protection scope of the present utility model.
[0031] Those parts not detailed in the present utility model are all well-known technologies to those skilled in the art of this technology.
Claims
1. A bearing seal protection structure for an LNG booster pump, comprising a housing, a stator and a rotor are arranged inside the housing, an end cover is arranged at the end of the housing, a volute is installed outside the end cover, an impeller is arranged inside the volute, the rotor passes through the end cover and is connected to the impeller, an air inlet and an air outlet are arranged on the volute, and it is characterized in that: A rotor sleeve is provided outside the rotor. One end of the rotor sleeve is closed, and the other end is provided with a flange. The closed end of the rotor sleeve is fixedly connected to the housing, and the flange of the rotor sleeve is fixedly connected to the end cover by bolts. A first bearing is provided inside the closed end of the rotor sleeve for supporting one end of the rotor. A second bearing for supporting the other end of the rotor is provided inside the end cover. A seal is provided between the end cover and the rotor for isolating the second bearing from the impeller.
2. The bearing seal protection structure of an LNG booster pump according to claim 1, characterized in that: The thickness of the rotor sleeve between the stator and the rotor is less than the thickness of the rotor sleeve at the first bearing and the flange.
3. The bearing seal protection structure of an LNG booster pump according to claim 1, characterized in that: The thickness of the rotor sleeve between the stator and the rotor does not exceed 1 mm.
4. A bearing seal protection structure for an LNG booster pump according to claim 1, characterized in that: The stator is in contact fit with the rotor sleeve, and the rotor is spaced from the rotor sleeve.
5. A bearing seal protection structure for an LNG booster pump according to claim 1, characterized in that: The closed end of the rotor sleeve is connected to the housing by interference press-fitting.
6. The bearing seal protection structure of an LNG booster pump according to claim 1, characterized in that: The rotor sleeve is made of stainless steel.
7. The bearing seal protection structure of an LNG booster pump according to claim 1, characterized in that: A sealing ring is provided between the flange and the end cover.
8. The bearing seal protection structure of an LNG booster pump according to claim 1, characterized in that: The seal is fixed in the groove of the end cover, and the rotor is in clearance fit with the seal.