Combined sealing structure for engine

Abstract

The present invention relates to a combined sealing structure for an engine, belonging to the technical field of mechanical seals, and comprises a double-end face isolation seal between the fuel gas and the liquid combustion aid and a single-end face seal located on both sides of the double-end face isolation seal. The single-end face seals located on both sides of the double-end face isolation seal are used to limit the leakage of the fuel gas and the liquid combustion aid. The double-end face isolation seal is used to isolate a small amount of medium leaked from the single-end face seals on both sides. Two groups of single-end face seals are also arranged between the fuel gas and the liquid fuel. The present invention has the advantage of isolating the fuel gas from the combustion aid, and the fuel from the fuel.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical seals, and in particular to a combined seal structure for an engine. Background Art

[0002] Mechanical seal is a shaft sealing device for fluid rotating machinery, also known as end face seal. Traditional contact mechanical seals are fully fitted under the action of the elastic force of the compensation mechanism to prevent the sealing medium from leaking from the sealing end faces. However, mechanical seals also have their shortcomings. The friction pair composed of the dynamic / static rings is generally in a state of boundary friction or mixed friction. Under high parameters (high temperature, high pressure, high speed, etc.), the friction coefficient is large, the power consumption is high, the wear is serious, the life is short, and the use and maintenance costs are high. Especially when used in the engine, because the engine uses high-temperature and high-pressure gas to drive the impeller to rotate, and the other part of the engine needs to use liquid combustion aid, due to the long-term wear of the mechanical seal, there will be a gap between the friction pairs composed of the dynamic / static rings, which will make the sealing effect poor, resulting in leakage of both the gas and the liquid combustion aid, making it easy to explode after the two come into contact. Summary of the invention

[0003] The object of the present invention is to provide a combined sealing structure for an engine, which has the advantage of being able to completely isolate the fuel gas from the combustion aid and thereby prevent the fuel gas leaking from the seals on both sides and the liquid combustion aid from mixing and exploding.

[0004] The above object of the present invention is achieved through the following technical solutions:

[0005] A combined sealing structure for an engine, comprising a double-end-face isolation seal between the fuel gas and the liquid combustion aid and single-end-face seals located on both sides of the double-end-face isolation seal, wherein the double-end-face isolation seal is used to isolate the medium on both sides of the double-end-face isolation seal, and the single-end-face seals located on both sides of the double-end-face isolation seal are used to limit the leakage of the fuel gas and the liquid combustion aid;

[0006] The double-end surface isolation seal comprises a central sleeve, a double-end surface dynamic ring, a first spring, a first spring seat and a first static ring, wherein the central sleeve is arranged on the engine rotating shaft and rotates synchronously with the engine rotating shaft, the double-end surface dynamic ring is arranged on the central sleeve, the first static ring is respectively arranged on both sides of the double-end surface dynamic ring and is in sealing contact with the double-end surface dynamic ring, the first spring seat is arranged on the engine housing, the first spring is arranged on the first spring seat and the first static ring is arranged at one end of the first spring away from the first spring seat;

[0007] The single-end face seal comprises a single-end face dynamic ring, a second static ring, a second spring and a second spring seat, wherein the single-end face dynamic ring is arranged on the engine rotating shaft and rotates synchronously with the engine rotating shaft, the second spring seat is arranged on the engine housing, the second spring is arranged on the second spring seat, and the second static ring is arranged at one end of the second spring away from the second spring seat and is in sealing contact with the single-end face dynamic ring;

[0008] An injection channel for the isolation gas to enter is provided between the two first spring seats, the sealing contact end faces of the double-end face dynamic ring and the first static ring are connected with the injection channel, an exhaust channel for gas discharge is provided between the first spring seat and the second spring seat, and the medium leaking from the single-end face seals on both sides is also discharged from the two exhaust channels respectively;

[0009] Two sets of single-end face seals are also arranged between the gas and the liquid fuel, one set of single-end face seals is located on the gas side, and the other set of single-end face seals is located on the liquid fuel side. An exhaust cavity for discharging leaked gas and leaked fuel is arranged between the two second spring seats between the two sets of single-end face seals.

[0010] Implement the above technical solution, start the engine, let the engine shaft start to drive the double-end face moving ring to rotate, and then inject inert gas into the gas injection channel. Since the sealing contact end face of the double-end face moving ring and the first static ring is located in the gas injection channel, during the rotation of the double-end face moving ring, the inert gas will enter the sealing end face of the double-end face moving ring and the first static ring and generate an air film. At this time, the double-end face moving ring and the first static ring will be filled with inert gas, separating the end face of the double-end face moving ring from the end face of the first static ring, so that the end faces of the two are not in direct contact, and the wear of the sealing end faces of the two is reduced; then the inert gas will continue to enter the gap between the engine rotating shaft and the engine housing through the sealing end face between the double-end face moving ring and the first static ring, and at the single-end face moving ring and the second static ring on both sides of the engine rotating shaft, these two places are sealed by contact sealing, so that the fuel gas and liquid combustion aid are not easy to leak into the gap between the engine rotating shaft and the engine housing on both sides. If there is still some fuel gas and liquid combustion aid leaking into the gap between the engine shaft and the engine casing, the inert gas filled in the gap between the engine shaft and the engine casing will block the fuel gas and the liquid combustion aid respectively, and finally the inert gas will discharge the fuel gas in the gap between the engine shaft and the engine casing from the exhaust duct under pressure, and at the same time the inert gas will also discharge the liquid combustion aid in the gap between the engine shaft and the engine casing from another exhaust duct, so that the fuel gas and the liquid combustion aid will not come into contact with each other under the isolation of the inert gas; that is, after the engine is started, there may be slight end face leakage of the fuel and the combustion aid between the single-end face dynamic rings and the second static ring on both sides, and a slightly higher pressure inert gas is injected through the middle isolation seal to achieve the purpose of isolating the fuel and flame retardant leaking from the seals at both ends. Similarly, the two sets of single-end face seals between the fuel gas and the liquid fuel also achieve the purpose of blocking the fuel gas and the liquid fuel. The two end faces of the isolation seal formed by the double-end face dynamic ring in the middle will form a tiny air film, thereby reducing the consumption of inert gas and realizing the isolation of fuel gas and liquid combustion aid, completely avoiding the explosion caused by the mixing of fuel gas and liquid combustion aid leaking from the seals on both sides; in general, the end face seals at both ends are used to prevent or reduce the leakage of fuel and combustion aid, and the isolation seal in the middle is to prevent the mixing of a small amount of fuel and combustion aid leaking from the seals on both sides, thereby effectively reducing the consumption of isolated inert gas and improving the isolation reliability of the seal.

[0011] Furthermore, the first spring makes the first stationary ring always have a tendency to move toward the double-end-surface dynamic ring side, and the second spring makes the second stationary ring always have a tendency to move toward the single-end-surface dynamic ring side.

[0012] By implementing the above technical solution, the first spring makes the first static ring always press against the double-end dynamic ring to form a mechanical seal, and the second spring makes the second static ring always press against the single-end dynamic ring to form a mechanical seal, thereby achieving a better sealing effect.

[0013] Furthermore, the double-end face isolation seal adopts the form of fluid dynamic pressure end face seal, and the double-end face dynamic ring is provided with a shallow groove for gas to enter.

[0014] By implementing the above technical solution, the provision of the shallow groove can allow the inert gas to be more stably located in the sealing end face composed of the dynamic / static ring, thereby achieving a better isolation effect of the sealing end face of the dynamic / static ring.

[0015] Furthermore, sealing rings are provided between the first spring seat and the engine housing, and between the second spring seat and the engine housing.

[0016] By implementing the above technical solution, the sealing ring can seal the gaps between the first spring seat and the engine housing, and between the second spring seat and the engine housing, so that the gas and the liquid combustion aid are not easy to leak out from the gaps.

[0017] Furthermore, a shallow groove for gas to enter is also provided on the single-end surface moving ring located on the gas side.

[0018] By implementing the above technical solution, the setting of the shallow groove here can allow the fuel gas to act as an isolation gas, separating the single-end dynamic ring from the sealing end face of the second static ring, reducing the wear of the two. Due to the obstruction of the inert gas, the fuel gas will also be blocked by the inert gas for the second time after leakage, so that the fuel gas will not come into contact with the liquid combustion aid or liquid fuel.

[0019] Furthermore, the two sets of single-end face seals between the gas and the liquid fuel are both in the form of contact-type mechanical seals.

[0020] By implementing the above technical solution, the sealing effect produced by the contact mechanical seal is more intuitive.

[0021] In summary, the present invention has the following beneficial effects:

[0022] 1. The present invention achieves the isolation of gas and liquid combustion aid, and to a certain extent avoids the explosion caused by the mixture of gas and liquid combustion aid leaking from the seals on both sides;

[0023] Second, the present invention also achieves isolation of gas and liquid fuel, and to a certain extent avoids contact between gas and liquid fuel due to leakage from the seals on both sides. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a sealing structure between high-temperature and high-pressure fuel gas and a liquid combustion aid according to an embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of the sealing structure between liquid fuel and high-temperature and high-pressure gas according to an embodiment of the present invention.

[0026] Figure numerals: 1. Double-end face isolation seal; 11. Center sleeve; 12. Double-end face dynamic ring; 13. First spring; 14. First spring seat; 15. First static ring; 2. Single-end face seal; 21. Single-end face dynamic ring; 22. Second static ring; 23. Second spring; 24. Second spring seat; 3. Air injection channel; 4. Exhaust channel; 5. Exhaust chamber; 6. Sealing ring; 7. Engine housing; 8. Engine rotating shaft. DETAILED DESCRIPTION

[0027] The technical solution of the embodiment of the present invention will be described below in conjunction with the accompanying drawings.

[0028] like Figure 1 , 2 As shown, a combined sealing structure for an engine includes a double-face isolation seal 1 between the fuel gas and the liquid combustion aid and a single-face seal 2 located on both sides of the double-face isolation seal 1 (in this sealing structure, from left to right are liquid fuel, fuel gas and liquid combustion aid respectively), the double-face isolation seal 1 is used to isolate the medium on both sides of the double-face isolation seal 1, and the single-face seal 2 located on both sides of the double-face isolation seal 1 is used to limit the leakage of the medium on the fuel gas side and the liquid combustion aid side.

[0029] like Figure 1 , 2 As shown, the double-end surface isolation seal 1 includes a center sleeve 11, a double-end surface dynamic ring 12, a first spring 13, a first spring seat 14 and a first static ring 15. The center sleeve 11 is arranged on the engine rotating shaft 8, and the center sleeve 11 rotates synchronously with the engine rotating shaft 8. The double-end surface dynamic ring 12 is arranged on the center sleeve 11. The first static ring 15 is respectively arranged on both sides of the double-end surface dynamic ring 12 and is in sealing contact with the double-end surface dynamic ring 12. The double-end surface dynamic ring 12 is provided with a shallow groove for gas to enter, that is, a shallow groove is opened on the end face of the double-end surface dynamic ring 12 facing the first static ring 15 side. The setting of the shallow groove can make the inert gas more stably in the sealing end face composed of the dynamic / static rings, so that the sealing end faces of the dynamic / static rings can achieve better isolation effect.

[0030] like Figure 1 , 2 As shown, the first spring seat 14 is arranged on the engine housing 7, the first spring 13 is arranged on the first spring seat 14, and the first stationary ring 15 is arranged at one end of the first spring 13 away from the first spring seat 14. The first spring 13 makes the first stationary ring 15 always have a tendency to move toward the double-end surface dynamic ring 12 side.

[0031] like Figure 1 , 2 As shown, the double-end face isolation seal 1 adopts the form of fluid dynamic pressure end face seal, that is, there is no direct contact between the opposite surfaces of the double-end face dynamic ring 12 and the first static ring 15, but the middle is filled with inert gas. The sealing is achieved by the existence of the inert gas in the middle, which can reduce the wear of the double-end face dynamic ring 12 and the first static ring 15 and achieve the sealing effect.

[0032] like Figure 1 , 2 As shown, the single-end face seal 2 includes a single-end face dynamic ring 21, a second static ring 22, a second spring 23 and a second spring seat 24. The single-end face dynamic ring 21 is arranged on the engine rotating shaft 8, and the single-end face dynamic ring 21 rotates synchronously with the engine rotating shaft 8. The second spring seat 24 is arranged on the engine housing 7. The second spring 23 is arranged on the second spring seat 24. The second static ring 22 is arranged at one end of the second spring 23 away from the second spring seat 24 and is in sealing contact with the single-end face dynamic ring 21. The second spring 23 makes the second static ring 22 always have a tendency to move toward the side of the single-end face dynamic ring 21.

[0033] like Figure 1 , 2 As shown, an injection channel 3 for the isolation gas to enter is provided in the middle of the two first spring seats 14, the sealing contact end faces of the double-end face dynamic ring 12 and the first static ring 15 are connected to the injection channel 3, and an exhaust channel 4 for gas discharge is provided between the first spring seat 14 and the second spring seat 24, and the medium leaking from the single-end face seals 2 on both sides is also discharged from the two exhaust channels 4 respectively.

[0034] like Figure 1 , 2 As shown, two groups of single-end face seals 2 are also arranged between the gas and the liquid fuel. The two groups of single-end face seals 2 between the gas and the liquid fuel are in the form of contact mechanical seals, one group of single-end face seals 2 is located at the gas side, and the other group of single-end face seals 2 is located at the liquid fuel, that is, the single-end face seal 2 between the gas and the liquid fuel also includes a single-end face dynamic ring 21, a second static ring 22, a second spring 23 and a second spring seat 24. The single-end face dynamic ring 21 is arranged on the engine rotating shaft 8, and the single-end face dynamic ring 21 rotates synchronously with the engine rotating shaft 8. The second spring seat 24 is arranged on the engine housing 7, and the second spring 23 is arranged on the second spring seat 24. The second static ring 22 is arranged at one end of the second spring 23 away from the second spring seat 24 and is in sealing contact with the single-end face dynamic ring 21. The second spring 23 makes the second static ring 22 always have a tendency to move toward the single-end face dynamic ring 21 side.

[0035] An exhaust cavity 5 for the leaked gas and leaked fuel to be discharged is arranged between the two second spring seats 24 between the two groups of single-end face seals 2, and a shallow groove for the gas to enter is also arranged on the single-end face dynamic ring 21 located at the gas. The setting of the shallow groove here enables the gas to act as an isolation gas, separating the single-end face dynamic ring 21 from the sealing end face of the second static ring 22, thereby reducing the wear of the two. Due to the obstruction of the inert gas, the gas will also be secondary blocked by the inert gas after leakage, so that the gas will not come into contact with the liquid combustion aid or liquid fuel.

[0036] like Figure 1 , 2 As shown, sealing rings 6 are provided between the first spring seat 14 and the engine housing 7, and between the second spring seat 24 and the engine housing 7. The setting of the sealing rings 6 can seal the gaps between the first spring seat 14 and the engine housing 7, and between the second spring seat 24 and the engine housing 7, so that the gas and liquid combustion aid are not easy to leak out from the gaps.

[0037] Specific working process: start the engine, let the engine rotating shaft 8 start to drive the double-end surface moving ring 12 to rotate, and then inject inert gas into the gas injection channel 3. Since the sealing contact end surface of the double-end surface moving ring 12 and the first static ring 15 are located in the gas injection channel 3, during the rotation of the double-end surface moving ring 12, the inert gas will enter the sealing end surface of the double-end surface moving ring 12 and the first static ring 15 and generate an air film. At this time, the double-end surface moving ring 12 and the first static ring 15 will be filled with inert gas, and the end surface of the double-end surface moving ring 12 and the first static ring 15 will be sealed. 5, so that the end faces of the two are not in direct contact, and the wear of the sealing end faces of the two is reduced; then the inert gas will continue to enter the gap between the engine rotating shaft 8 and the engine housing 7 through the sealing end face between the double-end face dynamic ring 12 and the first static ring 15, and at the single-end face dynamic ring 21 and the second static ring 22 on both sides of the engine rotating shaft 8, these two places are sealed by contact sealing, so that the fuel gas and liquid combustion aid are not easy to leak into the gap between the engine rotating shaft 8 and the engine housing 7 on both sides. If there is still some gas and liquid combustion aid leaking into the gap between the engine rotating shaft 8 and the engine casing 7, the inert gas filled in the gap between the engine rotating shaft 8 and the engine casing 7 will block the gas and the liquid combustion aid respectively, and finally the inert gas will discharge the gas between the engine rotating shaft 8 and the engine casing 7 from the exhaust duct 4 under pressure, and at the same time the inert gas will also discharge the liquid combustion aid in the gap between the engine rotating shaft 8 and the engine casing 7 from another exhaust duct 4, so that the gas and the liquid combustion aid will not come into contact with each other under the isolation of the inert gas; that is, after the engine is started, there may be slight end face leakage of the fuel and the combustion aid between the single-end face dynamic ring 21 and the second static ring 22 on both sides, and the inert gas with slightly higher pressure is injected through the middle isolation seal to achieve the purpose of isolating the fuel and flame retardant leaking from the two end seals. Similarly, the two sets of single-end face seals 2 between the gas and the liquid fuel also achieve the purpose of blocking the gas and the liquid fuel. The two end faces of the isolation seal formed by the double-end face dynamic ring 12 in the middle will form a tiny air film, thereby reducing the consumption of inert gas and realizing the isolation of fuel gas and liquid combustion aid, completely avoiding the explosion caused by the mixing of fuel gas and liquid combustion aid leaking from the seals on both sides; in general, the end face seals at both ends are used to prevent or reduce the leakage of fuel and combustion aid, and the middle isolation seal is used to prevent the mixing of a small amount of fuel and combustion aid leaking from the seals on both sides, thereby effectively reducing the consumption of isolated inert gas and improving the isolation reliability of the seal.

Claims

1. A combined sealing structure for an engine, comprising a double-end-face isolation seal (1) between the fuel gas and the liquid combustion aid and single-end-face seals (2) located on both sides of the double-end-face isolation seal (1), wherein the double-end-face isolation seal (1) is used to isolate the medium on both sides of the double-end-face isolation seal (1), and the single-end-face seals (2) located on both sides of the double-end-face isolation seal (1) are used to limit the leakage of the fuel gas and the liquid combustion aid, characterized in that : The double-end surface isolation seal (1) comprises a central sleeve (11), a double-end surface dynamic ring (12), a first spring (13), a first spring seat (14) and a first stationary ring (15); the central sleeve (11) is arranged on an engine rotating shaft (8) and rotates synchronously with the engine rotating shaft (8); the double-end surface dynamic ring (12) is arranged on the central sleeve (11); the first stationary ring (15) is respectively arranged on both sides of the double-end surface dynamic ring (12) and is in sealing contact with the double-end surface dynamic ring (12); the first spring seat (14) is arranged on an engine housing (7); the first spring (13) is arranged on the first spring seat (14); and the first stationary ring (15) is arranged at one end of the first spring (13) away from the first spring seat (14); The single-end face seal (2) comprises a single-end face dynamic ring (21), a second static ring (22), a second spring (23) and a second spring seat (24); the single-end face dynamic ring (21) is arranged on the engine rotating shaft (8) and rotates synchronously with the engine rotating shaft (8); the second spring seat (24) is arranged on the engine housing (7); the second spring (23) is arranged on the second spring seat (24); the second static ring (22) is arranged at one end of the second spring (23) away from the second spring seat (24) and is in sealing contact with the single-end face dynamic ring (21); An injection channel (3) for the isolation gas to enter is provided between the two first spring seats (14); the sealing contact end faces of the double-end face dynamic ring (12) and the first static ring (15) are in communication with the injection channel (3); an exhaust channel (4) for gas discharge is provided between the first spring seat (14) and the second spring seat (24); and the medium leaking from the single-end face seals (2) on both sides is also discharged from the two exhaust channels (4) respectively; Two groups of single-end face seals (2) are also arranged between the gas and the liquid fuel, wherein one group of single-end face seals (2) is located at the gas side and the other group of single-end face seals (2) is located at the liquid fuel side, and an exhaust cavity (5) for exhausting leaked gas and leaked fuel is arranged between two second spring seats (24) between the two groups of single-end face seals (2).

2. The engine combined sealing structure according to claim 1, characterized in that: The first spring (13) causes the first stationary ring (15) to always have a tendency to move toward the double-end-face dynamic ring (12) side, and the second spring (23) causes the second stationary ring (22) to always have a tendency to move toward the single-end-face dynamic ring (21) side.

3. The engine combined sealing structure according to claim 1, characterized in that: The double-end face isolation seal (1) adopts the form of fluid dynamic pressure end face seal, and the double-end face dynamic ring (12) is provided with a shallow groove for gas to enter.

4. The engine combined sealing structure according to claim 1, characterized in that: A sealing ring (6) is provided between the first spring seat (14) and the engine housing (7), and between the second spring seat (24) and the engine housing (7).

5. The engine combined sealing structure according to claim 1, characterized in that: The single-end-surface moving ring (21) located on the gas side is also provided with a shallow groove for gas to enter.

6. The engine combined sealing structure according to claim 1, characterized in that: The two sets of single-end face seals (2) between the gas and the liquid fuel are both in the form of contact type mechanical seals.

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