Active and passive coupling bearing sealing structure of underwater high-speed rotating machine

Abstract

The invention discloses an active and passive coupling bearing sealing structure of an underwater high-speed rotating machine, relates to the technical field of bearing sealing, and solves the problem that an existing bearing sealing structure is poor in underwater sealing effect. The device comprises a rotating shaft, a base and a sealing structure, the rotating shaft is coaxially and rotatably mounted in the base, and a bearing is arranged between the rotating shaft and the base; an oil supply pipeline and a lubricating cavity are arranged in the base, an oil return pipeline is arranged between the rotating shaft and the base, and the oil supply pipeline, the lubricating cavity and the oil return pipeline are sequentially communicated; one side of the lubricating cavity is opened and contacted with the bearing; the sealing structure comprises a driving sealing structure and a driven sealing structure, the driving sealing structure is installed in the base, and the rotating shaft is sleeved with the driven sealing structure; the active sealing structure is communicated with an air supply source, and air is introduced into a gap between the active sealing structure and the passive sealing structure. According to the underwater bearing sealing device, the sealing effect of an underwater bearing is improved in a mode of coupling active sealing and passive sealing.

Description

Technical Field

[0001] The invention relates to the technical field of bearing sealing, and in particular to an active and passive coupling bearing sealing structure of an underwater high-speed rotating machinery. Background Art

[0002] Bearings are an indispensable and important component in mechanical transmission. Their main functions include: bearing radial loads and axial loads from rotating parts, providing stable support for rotating parts so that they can rotate smoothly, reducing the friction coefficient between rotating parts and stationary parts, reducing the wear between rotating parts and stationary parts, and maintaining the rotation accuracy of rotating parts. However, when the rotating parts are running at high speed, the bearing oil may leak. The lubricating oil plays a role in lubrication, cooling, and cleaning during the operation of the bearing, improving the operating efficiency and life of the bearing. Once the lubricating oil leaks, it will inevitably reduce the effect of the lubricating oil and affect the service life of the bearing. At the same time, it will also increase the number and cost of maintenance; therefore, the bearing needs to be sealed tightly.

[0003] There are generally two types of existing bearing sealing structures. One is passive sealing, that is, sealing structures such as comb teeth sealing and graphite sealing are used. None of these sealing methods require active control, and a good sealing effect can be achieved when the mechanical system is working normally. The second is to introduce external air through the air system of the mechanical system itself, compress it, increase the pressure of the gas, and introduce the high-pressure gas into the bearing sealing cavity to achieve gas sealing of the bearing. However, as the power and thrust requirements of underwater rotary mechanical engines gradually increase, the engine speed needs to be increased accordingly. The existing sealing structure cannot be applied to underwater high-speed rotary mechanical engines. Since the engine cannot introduce air from the outside when working underwater, it is impossible to perform gas sealing of the bearing cavity. At the same time, since the engine is in a high-speed rotation state when running underwater, the traditional graphite sealing structure is a contact sealing structure, which will wear quickly during high-speed rotation, affecting the sealing effect.

[0004] Therefore, there is an urgent need for a bearing sealing structure that can be used in the operation of underwater high-speed rotating mechanical engines, and can achieve bearing sealing by actively supplying air to the front of the bearing cavity without the introduction of external air. Summary of the invention

[0005] In order to solve the problem of poor underwater sealing effect of the existing bearing sealing structure mentioned above, the present invention proposes an active and passive coupling bearing sealing structure of underwater high-speed rotating machinery. The present invention improves the underwater bearing sealing effect by coupling active sealing and passive sealing.

[0006] The present invention provides a main - passive coupled bearing sealing structure for an underwater high - speed rotating machine, which specifically includes a rotating shaft, a base, and a sealing structure. The rotating shaft is coaxially and rotatably installed inside the base, and a bearing is arranged between the rotating shaft and the base. An oil supply pipeline and a lubrication cavity are arranged inside the base, and an oil return pipeline is arranged between the rotating shaft and the base. The oil supply pipeline, the lubrication cavity, and the oil return pipeline are connected in sequence. One side of the lubrication cavity is open and in contact with the bearing. The sealing structure includes an active sealing structure and a passive sealing structure. The active sealing structure is installed inside the base, and the passive sealing structure is sleeved on the rotating shaft. The active sealing structure is connected to a gas supply source, and gas is introduced into the gap between the active sealing structure and the passive sealing structure.

[0007] Further, the active sealing structure includes a gas supply component, and an internal flow channel of the gas supply component is arranged inside the gas supply component. One side of the internal flow channel of the gas supply component is connected to the gas supply source, and the other side introduces gas into the gap between the active sealing structure and the passive sealing structure.

[0008] Further, the internal flow channel of the gas supply component includes an annular air duct and a plurality of air outlet holes. One side of the annular air duct is connected to the gas supply source, and the other side is connected to the plurality of air outlet holes.

[0009] Further, the passive sealing structure includes a graphite sealing structure. One side of the graphite sealing structure abuts against the bearing. The graphite sealing structure includes a graphite sealing support and a graphite sealing ring. The cross - section of the graphite sealing support is a concave - shaped structure, and the graphite sealing ring is arranged in the groove of the graphite sealing support.

[0010] Further, the distance between the graphite sealing ring and the gas supply component is not greater than 0.2 mm.

[0011] Further, the passive sealing structure further includes a labyrinth sealing structure. The labyrinth sealing structure abuts against one side of the graphite sealing structure, and a plurality of labyrinth teeth are arranged on the labyrinth sealing structure.

[0012] Further, the number of the labyrinth teeth is greater than or equal to 4 and less than or equal to 8.

[0013] Further, the distance between the labyrinth teeth and the gas supply component is greater than or equal to 0.2 mm and less than or equal to 0.4 mm.

[0014] Further, the air outlet holes are arranged between the labyrinth sealing structure and the graphite sealing ring.

[0015] Further, an oil injector is arranged at the outlet of the oil supply pipeline, and the oil injector is directed at the bearing.

[0016] The beneficial effects of the main - passive coupled bearing sealing structure for an underwater high - speed rotating machine according to the present invention are as follows:

[0017] (1) The main - passive coupled bearing sealing structure of an underwater high - speed rotating machine according to the present invention solves the problem of poor sealing effect of the existing bearing sealing structure underwater. Through the sealing structure that couples active sealing and passive sealing, a more efficient bearing sealing effect is achieved. When the underwater high - speed rotating mechanical engine is working, active sealing is the main sealing means, and passive sealing provides additional sealing guarantee for active sealing, improving the efficiency of active sealing. At the same time, through the reasonable design of the air supply flow path and the layout of the sealing structure, the sealing gas can reach the sealing area more effectively, enhancing the sealing performance.

[0018] (2) The main - passive coupled bearing sealing structure of an underwater high - speed rotating machine according to the present invention contacts the rotor through a graphite sealing structure to form a sealing surface, effectively preventing the lubricating oil from leaking from the bearing cavity to the external environment, and ensuring the cleanliness inside the engine and the normal circulation of the lubricating oil.

[0019] (3) When the air flow flowing out from the active sealing structure passes through the gap between the labyrinth teeth and the air supply component, it will experience multiple accelerations and expansions, resulting in a gradual decrease in pressure and velocity energy. This throttling and thermodynamic effect makes it difficult for the gas to "escape", thus effectively reducing the leakage of the oil - gas air flow. By blocking the leakage of the oil - gas air flow, the labyrinth seal reduces the consumption of the lubricating oil and ensures that the bearing is fully lubricated. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0021] In the drawings:

[0022] Figure 1 is the first structural schematic diagram of the main - passive coupled bearing sealing structure of an underwater high - speed rotating machine according to the present invention;

[0023] Figure 2 is the second structural schematic diagram of the main - passive coupled bearing sealing structure of an underwater high - speed rotating machine according to the present invention;

[0024] Figure 3 is the schematic diagram of the gas flow direction at the air outlet of the main - passive coupled bearing sealing structure of an underwater high - speed rotating machine according to the present invention;

[0025] Figure 4 is the perspective view of the air supply component of the main - passive coupled bearing sealing structure of an underwater high - speed rotating machine according to the present invention;

[0026] Figure 5It is a cross-sectional view of the air supply component of the main-passive coupling bearing sealing structure of an underwater high-speed rotating machine described in the present invention;

[0027] Figure 6 It is a three-dimensional structure schematic diagram of the labyrinth seal structure of the main-passive coupling bearing sealing structure of an underwater high-speed rotating machine described in the present invention;

[0028] Figure 7 It is a side view of the labyrinth seal structure of the main-passive coupling bearing sealing structure of an underwater high-speed rotating machine described in the present invention;

[0029] Figure 8 It is a side view of the graphite seal structure of the main-passive coupling bearing sealing structure of an underwater high-speed rotating machine described in the present invention;

[0030] Figure 9 It is a three-dimensional structure schematic diagram of the graphite seal structure of the main-passive coupling bearing sealing structure of an underwater high-speed rotating machine described in the present invention;

[0031] Wherein: 1 - air supply source, 2 - air source valve, 3 - external air supply pipeline, 4 - internal air flow channel, 5 - oil supply pipeline, 6 - fuel injector, 7 - oil return pipeline, 8 - rotating shaft, 9 - bearing, 10 - graphite seal support, 11 - graphite seal ring, 12 - labyrinth seal structure, 13 - internal flow channel of air supply component, 14 - air supply component, 15 - base. Specific embodiments

[0032] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Specific Embodiment 1: Refer to Figures 1-9 The main and passive coupled bearing sealing structure of an underwater high-speed rotating machine described in this embodiment specifically includes a rotating shaft 8, a base 15, and a sealing structure. The rotating shaft 8 is coaxially and rotatably installed inside the base 15. A bearing 9 is provided between the rotating shaft 8 and the base 15. An oil supply pipeline 5 and a lubrication chamber are provided inside the base 15. An oil return pipeline 7 is provided between the rotating shaft 8 and the base 15. The oil supply pipeline 5, the lubrication chamber, and the oil return pipeline 7 are connected in sequence. One side of the lubrication chamber is open and in contact with the bearing 9. An injection nozzle 6 is provided at the outlet of the oil supply pipeline 5. The injection nozzle 6 is directed at the bearing 9. Lubricating oil is sprayed out from the injection nozzle 6 to lubricate the bearing 9. The sealing structure includes an active sealing structure and a passive sealing structure. The active sealing structure is installed inside the base 15, and the passive sealing structure is sleeved on the rotating shaft 8. The active sealing structure is connected to a gas supply source 1, and gas is introduced into the gap between the active sealing structure and the passive sealing structure.

[0037] The active sealing structure includes a gas supply component 14. The gas supply component 14 is of a ring structure. The gas supply component 14 is coaxial with the rotating shaft 8 and installed inside the base 15. An internal flow channel 13 of the gas supply component is provided inside the gas supply component 14. The internal flow channel 13 of the gas supply component is of a ring structure. One side of the internal flow channel 13 of the gas supply component is connected to the gas supply source 1 through an internal gas flow channel 4 and an external gas supply pipeline 3, and the other side introduces gas into the gap between the active sealing structure and the passive sealing structure. A gas source valve 2 is provided on the external gas supply pipeline 3.

[0038] The internal flow channel 13 of the gas supply component includes an annular air duct and a plurality of air outlet holes. The annular air duct is coaxial with the rotating shaft 8. One side of the annular air duct is connected to the gas supply source 1, and the other side is connected to the plurality of air outlet holes. The plurality of air outlet holes are evenly arranged, and the outlets of the air outlet holes point to the axis of the rotating shaft 8.

[0039] The passive sealing structure includes a graphite sealing structure. The graphite sealing structure is coaxially sleeved on the rotating shaft 8 and rotates synchronously with the rotating shaft 8. One side of the graphite sealing structure abuts against the bearing 9. The graphite sealing structure includes a graphite sealing support 10 and a graphite sealing ring 11. The cross-section of the graphite sealing support 10 is a concave structure. The graphite sealing ring 11 is arranged in the groove of the graphite sealing support 10. The graphite sealing ring 11 contacts with the upper air supply component 14 to form a sealing surface. The graphite sealing ring 11 is made of carbon graphite or antimony-impregnated graphite material. The graphite sealing support 10 is composed of two spliced annular structures. One annular structure has an L-shaped cross-section, and the other annular structure has an l-shaped cross-section. The material is metal and is used to support and fix the graphite sealing ring 11.

[0040] The distance between the graphite sealing ring 11 and the air supply component 14 is not greater than 0.2 mm.

[0041] The passive sealing structure further includes a labyrinth sealing structure 12. The labyrinth sealing structure 12 is an annular structure and is coaxially installed on the rotating shaft 8 to rotate synchronously with the rotating shaft 8. The labyrinth sealing structure 12 abuts against one side of the graphite sealing structure. A number of labyrinth teeth are provided on the labyrinth sealing structure 12. The labyrinth teeth are annular structures. The number of labyrinth teeth has a certain height and is arranged at equal intervals. A sealing gap is formed between the labyrinth teeth and the upper air supply component 14.

[0042] The number of labyrinth teeth is greater than or equal to 4 and less than or equal to 8. The distance between the labyrinth teeth and the air supply component 14 is greater than or equal to 0.2 mm and less than or equal to 0.4 mm. The size of the gap has an important impact on the sealing performance. Too large a gap will lead to increased air leakage, and too small a gap may cause friction.

[0043] The air outlet hole is arranged between the labyrinth sealing structure 12 and the graphite sealing ring 11.

[0044] The specific working principle of the main and passive coupled bearing sealing structure of an underwater high-speed rotating machine according to the present invention is as follows:

[0045] As Figure 1 shown, when the engine is working underwater, the lubricating oil reaches the fuel injector 6 through the engine lubricating oil supply pipeline 5, and the lubricating oil is conveyed to the inside of the bearing cavity for lubricating the bearing 9. The excess lubricating oil returns to the lubricating oil tank through the oil return pipeline 7. At this time, the air source valve 2 is actively opened, and the high-pressure gas in the air supply source 1 passes through the external air supply pipeline 3 of the engine and supplies the high-pressure gas into the engine. After the high-pressure gas enters the engine, it enters the active air supply flow channel 13 inside the bearing front air supply component through the internal air supply flow channel 4. The cross-sectional shape and pipeline length of the external active air supply pipeline 3 of the engine and the internal active air supply flow channel 4 of the engine should be designed according to the lowest pressure loss criterion. Finally, the high-pressure gas passes through the outlet of the internal flow channel 13 of the air supply component and enters the bearing sealing cavity to achieve active sealing of the bearing 9.

[0046] The graphite sealing structure is a contact seal. However, during the operation of the engine, the graphite sealing ring 11 will rub against the upper air supply component 14, causing wear of the graphite sealing ring 11. As a result, a gap is formed between the graphite sealing ring 11 and the air supply component 14 at the front end of the bearing, leading to space for lubricating oil leakage. Therefore, an active sealing structure needs to be introduced. The labyrinth forms a sealing gap with the lower surface of the air supply component at the front end of the bearing. The size of the gap has an important impact on the sealing performance. An overly large gap will result in increased air leakage, while an overly small gap may cause friction. When the air flow passes through the gap between the labyrinth and the air supply component 14, it will experience multiple accelerations and expansions, resulting in a gradual decrease in pressure and velocity energy. This throttling effect makes it difficult for the gas to "escape", thus effectively reducing the air leakage loss.

[0047] The outlet of the internal flow passage 13 of the air supply component is between the labyrinth sealing structure 12 and the graphite sealing ring 11, and the graphite sealing ring 11 is close to the bearing 9 side, while the labyrinth sealing structure 12 is far from the bearing 9 side. After the gas flows out from the outlet of the internal flow passage 13 of the air supply component, a part of it flows towards the bearing 9 side to provide sealing pressure for the bearing sealing cavity; another part will flow towards the labyrinth sealing structure 12 side because the pressure in the engine chamber outside the labyrinth sealing structure 12 is relatively low, and then leaks to the external chamber. This structure can give full play to the roles of both the labyrinth sealing structure 12 and the graphite sealing ring 11, that is, reduce the leakage of the sealing gas at the outlet of the active air supply flow passage to the outside through the labyrinth sealing structure 12, ensure the pressure of the sealing gas on the sealing surface between the graphite sealing ring 11 and the air supply component 14 at the front end of the bearing, and better achieve the main-passive coupled sealing.

[0048] The pressure of the air supply source 1 can be adjusted by the opening degree of the air source valve 2. The pressure of the air supply source 1 needs to meet the requirement that the pressure of the gas reaching the bearing sealing cavity is greater than the bearing cavity pressure, reaching the standard to prevent lubricating oil leakage. When the gas enters the inlet of the internal flow passage 13 of the air supply component, the gas then enters the annular air passage. At this time, the gas flows along the annular air passage, realizing the circumferential uniform distribution of the gas. Then, the gas flows out from the circumferentially uniformly distributed air outlet holes below the annular air passage and reaches the bearing sealing cavity, avoiding the occurrence of lubricating oil leakage at local positions along the circumference of the bearing 9.

[0049] Summarizing the above embodiments, the main and passive coupled bearing sealing structure of an underwater high-speed rotating machine described in the present invention solves the problem of poor sealing effect of the existing bearing sealing structure underwater. Through the sealing structure coupled by active sealing and passive sealing, a more efficient bearing sealing effect is achieved. When the underwater high-speed rotating mechanical engine is working, active sealing is the main sealing means, and passive sealing provides additional sealing guarantee for active sealing, improving the efficiency of active sealing. At the same time, the reasonably designed air supply flow path and the layout of the sealing structure enable the sealing gas to reach the sealing area more effectively, enhancing the sealing performance. The main and passive coupled bearing sealing structure of an underwater high-speed rotating machine described in the present invention contacts the rotor through the graphite sealing structure to form a sealing surface, effectively preventing the lubricating oil from leaking from the bearing cavity to the external environment and ensuring the cleanliness inside the engine and the normal circulation of the lubricating oil. In the main and passive coupled bearing sealing structure of an underwater high-speed rotating machine described in the present invention, when the air flow flowing out of the active sealing structure passes through the gap between the labyrinth teeth and the air supply component 14, it will experience multiple accelerations and expansions, resulting in a gradual decrease in pressure and velocity energy. This throttling and thermodynamic effect makes it difficult for the gas to "escape", thus effectively reducing the leakage of the oil and gas air flow. By blocking the leakage of the oil and gas air flow, the labyrinth seal reduces the consumption of the lubricating oil and ensures that the bearing is fully lubricated.

[0050] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the invention. It can also be a reasonable combination of the features described in the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An active and passive coupling bearing sealing structure for underwater high-speed rotating machinery, characterized in that: The invention comprises a rotating shaft (8), a base (15) and a sealing structure. The rotating shaft (8) is coaxially rotatably mounted inside the base (15), and a bearing (9) is arranged between the rotating shaft (8) and the base (15); an oil supply pipeline (5) and a lubrication chamber are arranged inside the base (15), and an oil return pipeline (7) is arranged between the rotating shaft (8) and the base (15). The oil supply pipeline (5), the lubrication chamber and the oil return pipeline (7) are connected in sequence; one side of the lubrication chamber is open and contacts the bearing (9); the sealing structure comprises an active sealing structure and a passive sealing structure, the active sealing structure is mounted inside the base (15), and the passive sealing structure is sleeved on the rotating shaft (8); the active sealing structure is connected to an air supply source (1), and gas is introduced into the gap between the active sealing structure and the passive sealing structure.

2. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 1 is characterized in that: The active sealing structure comprises an air supply component (14), wherein an air supply component inner flow channel (13) is arranged inside the air supply component (14); one side of the air supply component inner flow channel (13) is connected to an air supply source (1), and the other side thereof allows gas to be introduced into the gap between the active sealing structure and the passive sealing structure.

3. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 2 is characterized in that: The inner flow channel (13) of the air supply component comprises an annular air channel and a plurality of air outlet holes; one side of the annular air channel is connected to the air supply source (1), and the other side is connected to the plurality of air outlet holes.

4. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 3 is characterized in that: The passive sealing structure comprises a graphite sealing structure, one side of the graphite sealing structure rests on the bearing (9), the graphite sealing structure comprises a graphite sealing support (10) and a graphite sealing ring (11), the cross section of the graphite sealing support (10) is a concave structure, and the graphite sealing ring (11) is arranged in a groove of the graphite sealing support (10).

5. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 4 is characterized in that: The distance between the graphite sealing ring (11) and the gas supply component (14) is no greater than 0.2 mm.

6. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 4 is characterized in that: The passive sealing structure also includes a comb teeth sealing structure (12), the comb teeth sealing structure (12) leans against one side of the graphite sealing structure, and a plurality of comb teeth are arranged on the comb teeth sealing structure (12).

7. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 6 is characterized in that: The number of the comb teeth is greater than or equal to 4 and less than or equal to 8.

8. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 6 is characterized in that: The distance between the comb teeth and the air supply component (14) is greater than or equal to 0.2 mm and less than or equal to 0.4 mm.

9. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 6, characterized in that: The air outlet is arranged between the comb tooth sealing structure (12) and the graphite sealing ring (11).

10. The active and passive coupling bearing sealing structure of underwater high-speed rotating machinery according to claim 1, characterized in that: The outlet of the oil supply pipeline (5) is provided with an oil spray nozzle (6), and the oil spray nozzle (6) is directly facing the bearing (9).

Images