Air sealing system of lateral propeller

Abstract

The invention discloses an air sealing system of a lateral propeller, and relates to the technical field of ships. The system is mainly composed of a propeller shaft seal, a driving shaft seal, an air control unit, a propeller shaft seal oil tank, a driving shaft seal oil tank, a lateral propeller seal oil tank, a propeller shaft seal lubricating oil pump unit, a driving shaft seal lubricating oil pump unit, a lateral propeller lubricating oil pump unit and a discharging and collecting unit. Through the application of the system, the sealing performance of the lateral thruster is improved, the service life of the sealing system is prolonged, the risk of lubricating oil leakage is reduced, pollution to the environment is reduced, and the reliability of the lateral thruster running in a complex water area is improved.

Description

Technical Field

[0001] The invention relates to the technical field of ships, and in particular to an air sealing system for a lateral thruster. Background Art

[0002] The existing lateral thruster air sealing system is mainly composed of the following five parts: propeller shaft seal, drive shaft seal, air control unit, lateral thruster seal oil tank, and discharge collection unit.

[0003] The disadvantages of the existing lateral thruster air sealing system are as follows: The drive shaft seal is not introduced into the sealing system, so the drive shaft seal ring is subjected to great pressure, and the wear between it and the drive shaft bushing will be very serious, and the service life will be greatly reduced; and the drive shaft seal ring is in grease lubrication, and due to the high speed of the drive axis line and severe heat, the sealing effect and service life of the seal ring will be seriously affected.

[0004] The lateral thruster body has no lubricating oil pump unit and is unable to filter and cool the oil. Under long-term operation, the impurity content inside the lateral thruster body will continue to increase, which will seriously affect the service life of seals, bearings and gears, and may cause serious leakage risks and economic losses.

[0005] The number of sealing rings used to prevent lubricating oil leakage in the propeller shaft is too small. Once the sealing ring fails, a large amount of oil inside the thruster body is at risk of being contaminated by seawater. Summary of the invention

[0006] The present invention provides an air sealing system for a lateral thruster. Through the application of the system, the sealing performance of the lateral thruster is improved, the service life of the sealing system is extended, the risk of lubricating oil leakage is reduced, the pollution to the environment is reduced, and the reliability of the lateral thruster in operation in complex waters is improved.

[0007] According to one aspect of the present disclosure, a lateral thruster air sealing system is provided, the system comprising: a propeller shaft seal, a drive shaft seal, an air control unit, a lateral thruster sealing oil tank, and a discharge collection unit, wherein the system further comprises: Propeller shaft sealing oil tank, drive shaft sealing oil tank, propeller shaft sealing oil pump unit, drive shaft sealing oil pump unit, lateral thruster oil pump unit; The compressed air on board enters the propeller shaft seal oil tank after being filtered, decompressed and adjusted by the air control unit. Then the propeller shaft seal lubricating oil pump unit transports the oil in the propeller shaft seal oil tank to the annular cavity formed by the #3 / #4 sealing ring of the propeller shaft seal, and then returns to the propeller shaft seal oil tank; The compressed air on board is filtered by the air control unit, decompressed, and the flow is adjusted. The air is decompressed again by the flow restrictor and then enters the lateral thruster sealing oil tank. Then the lateral thruster lubricating oil pump unit transports the oil in the lateral thruster sealing oil tank into the lateral thruster body, and then returns to the lateral thruster sealing oil tank. The lubricating oil in the chamber formed by the #5 / #6 sealing ring of the drive shaft seal is provided by the circulating oil of the drive shaft seal lubricating oil pump unit. There is a height difference between the drive shaft seal oil tank and the drive shaft seal. The pressure of the chamber formed by the #5 / #6 sealing ring of the drive shaft seal is controlled to be lower than the pressure in the thrust body. The pressure difference is controlled within 0.05MPa.

[0008] In one possible implementation, the propeller shaft sealing oil tank includes: a safety valve SV1, an air pressure high alarm switch A2 connected to the propeller shaft sealing oil tank through a valve V15, a low air pressure alarm switch A3 connected to the propeller shaft sealing oil tank through a valve V14, an oil level high and low alarm switch A4, and a relief valve V16.

[0009] In a possible implementation, the chamber formed by the #5 / #6 sealing rings of the drive shaft seal B is connected to the drive shaft seal oil tank and the drive shaft seal lubricating oil pump unit; The drive shaft seal oil tank is equipped with an oil level high and low alarm switch A13. When the #5 seal ring of the drive shaft seal is damaged, the high level switch alarms. When the #6 seal ring of the drive shaft seal is damaged, the low level switch alarms. The drive shaft seal oil tank includes a drain valve V44.

[0010] In a possible implementation, the propeller shaft seal lubricating oil pump unit includes: a filter F3, a motor M1 and a motor M2, a main pump PU1 and a standby pump PU2, and a first lubricating oil cooler; the main pump PU1 and the standby pump PU2 are connected in parallel; The filter F3 is equipped with a one-way valve D2 and a differential pressure transmitter A5. When the filter F3 is clogged, the differential pressure transmitter A5 sends out an alarm signal, the one-way valve D2 opens, and the oil flows from the one-way valve D2 to the subsequent pipeline. The main pump PU1 and PU2 are standby pumps. When the differential pressure indicator DP2 exceeds the set value, the standby pump PU2 is activated. A one-way valve D5 is connected in parallel to the first lubricating oil cooler. When the first lubricating oil cooler is blocked, the oil will enter the propeller shaft seal through the one-way valve D5. At this time, the ball valves V23 and V24 are closed, and the first lubricating oil cooler is removed for maintenance. Motor M1 is used to drive the PU1 main pump, and M2 is used to drive the PU2 standby pump; The upstream and downstream of the differential pressure indicator DP2 are connected in series with valves V18 and V22 respectively; The upstream and downstream of the PU1 main pump are connected in series with valve V20 and check valve D3 respectively; the upstream and downstream of the PU2 standby pump are connected in series with valve V19 and check valve D4 respectively; The first lubricating oil cooler is connected in series downstream of the main pump PU1. WI1 and WO1 of the first lubricating oil cooler are respectively the water inlet and the water outlet of the first lubricating oil cooler.

[0011] In a possible implementation, the drive shaft seal lubricating oil pump unit includes: a filter F6, a motor M3 and a motor M4, a main pump PU3 and a standby pump PU4; the motor M3 is used to drive the PU3 main pump, and the motor M4 is used to drive the PU4 standby pump; The filter F6 is equipped with a one-way valve D12 and a differential pressure transmitter A11. When the filter F6 is clogged, the differential pressure transmitter A11 sends out an alarm signal, the one-way valve D12 opens, and the oil flows from the one-way valve D12 to the subsequent pipeline; Downstream of the filter F6, the main pump PU3 and the standby pump PU4 are connected in parallel, the motor M3 is used to drive the main pump PU3, the motor M4 is used to drive the standby pump PU4, the upstream of the main pump PU3 is connected in series with the valve V47 and the downstream is connected in series with the check valve D13, the upstream of the standby pump PU4 is connected in series with the valve V46 and the downstream is connected in series with the check valve D14, the downstream of the main pump PU3 is connected to the pressure gauge P7 and the pressure difference transmitter A12 through the valve V49 and the valve V50 respectively, the pressure gauge P7 is used at the outlet of the drive shaft seal lubricating oil pump; The main pump PU3 and the backup pump PU4 are used in pairs, and when the pressure sensor A12 is lower than the set value, the backup pump PU4 is enabled, which will not affect the operation of the system. Once the lubricating oil pump unit fails and cannot operate, manually open the ball valve V48 to ensure the normal operation of the system.

[0012] In a possible implementation, the lateral thruster oil pump unit includes: a motor M5 and a motor M6, a main pump PU5 and a standby pump PU6, a second oil cooler and a duplex filter F4 and a filter F5; the upstream of the duplex filter F4 and the filter F5 is connected to the second oil cooler, the upstream and downstream of the second oil cooler are connected to the ball valve V38 and the ball valve V39, the upstream of the ball valve V38 is connected to the pressure sensor A10 and the pressure gauge P6 through the valve 37 and the valve 36 respectively, and the pressure gauge P6 is used to measure the pressure of the lateral thruster oil pump; the upstream of the ball valve V38 is connected to the main pump PU5 and the standby pump PU6, the main pump PU5 and the standby pump PU6 are connected in parallel, the motor M5 is used to drive the PU5 main pump, and the motor M6 is used to drive the PU6 standby pump; The upstream of main pump PU5 is connected in series with valve V35 and the downstream of it is connected in series with check valve D7; the upstream of standby pump PU6 is connected in series with valve V35 and the downstream of it is connected in series with check valve D7; The main pump PU5 and the backup pump PU6 are used as one for use and one for backup. When the pressure sensor A10 is lower than the set value, the backup pump PU6 is enabled and will not affect the operation of the system. The second lubricating oil cooler is connected in parallel with a one-way valve D9. When the second lubricating oil cooler is blocked, the oil will enter the lateral thruster through the one-way valve D9. At this time, close the ball valves V38 and V39, and remove the second lubricating oil cooler for maintenance. The duplex filter is equipped with a one-way valve D10, a one-way valve D11 and a pressure differential transmitter A9. When the filter F4 is blocked, the pressure differential transmitter A9 sends an alarm signal, the one-way valve D10 opens, and the oil flows from the one-way valve D10 to the rear pipeline. At this time, the handle of the duplex filter should be switched to the other side, the filter F5 should be enabled, and the filter element of the filter F4 should be removed for cleaning or replacement.

[0013] Compared with the prior art, the present invention has the following beneficial effects: A lateral thruster air sealing system of the embodiment of the present disclosure is mainly composed of the following ten parts: A propeller shaft seal, B drive shaft seal, C air control unit, D propeller shaft seal oil tank, E drive shaft seal oil tank, F lateral thruster seal oil tank, G propeller shaft seal lubricating oil pump unit, H drive shaft seal lubricating oil pump unit, I lateral thruster lubricating oil pump unit, and J discharge collection unit. The purpose of the present invention is to provide a lateral thruster air sealing system, through the application of the system, the sealing performance of the lateral thruster is improved, the service life of the sealing system is extended, the risk of lubricating oil leakage is reduced, the pollution to the environment is reduced, and the reliability of the lateral thruster in complex waters is improved.

[0014] The above-mentioned lateral thruster air sealing system forms all the seals of the lateral thruster system into a whole by adding a lateral thruster sealing oil tank and a drive shaft sealing oil tank, so that the pressure on each seal can be controlled below 0.05MPa, which can effectively improve the sealing effect of the sealing ring and extend its service life.

[0015] The drive shaft seal lubricating oil pump unit was introduced, and the traditional drive shaft seal grease lubrication method was changed to oil lubrication. The oil can be circulated, which has the effect of heat dissipation and cooling, improves the working condition of the drive shaft seal ring, and introduces high and low liquid level sensors. Once a leak occurs, the fault can be discovered and eliminated in time.

[0016] A flow restrictor is added in front of the lateral thruster sealing oil tank to reduce the pressure on the drive shaft #5 seal ring, allowing it to use a common seal, reducing costs, and allowing the entire lateral thruster to adapt to deeper draft conditions, increasing its application range.

[0017] Combining the lateral thruster sealing oil tank with the lateral thruster lubricating oil pump unit streamlines the pipeline, allows the oil in the lateral thruster sealing oil tank to circulate, and continuously filters and cools the oil, thereby improving the operating conditions of the bearings and gears inside the lateral thruster and reducing the impact of shortening their service life due to oil contamination. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A block diagram of an existing lateral thruster air sealing system according to an embodiment of the present disclosure is shown.

[0019] Figure 2 A schematic block diagram of an improved lateral thruster air sealing system according to an embodiment of the present disclosure is shown.

[0020] Figure 3 A diagram showing a propeller shaft seal structure according to an embodiment of the present disclosure is shown.

[0021] Figure 4 A diagram showing a drive shaft seal structure according to an embodiment of the present disclosure is shown.

[0022] Figure 5 A schematic diagram of an air control unit according to an embodiment of the present disclosure is shown.

[0023] Figure 6 A schematic diagram of a propeller shaft sealing oil box according to an embodiment of the present disclosure is shown.

[0024] Figure 7 A schematic diagram of a drive shaft sealing oil tank according to an embodiment of the present disclosure is shown.

[0025] Figure 8 A schematic diagram of a lateral thruster sealing oil tank according to an embodiment of the present disclosure is shown.

[0026] Fig. 9 A schematic diagram of a propeller shaft seal lubricating oil pump unit according to an embodiment of the present disclosure is shown.

[0027] Fig.10 A schematic diagram of a drive shaft seal lubricating oil pump unit according to an embodiment of the present disclosure is shown.

[0028] Fig.11 A schematic diagram of a lateral thruster oil pump unit according to an embodiment of the present disclosure is shown.

[0029] Fig.12 A schematic diagram of a discharge collection unit according to an embodiment of the present disclosure is shown.

[0030] Figure markings: 1-propeller shaft, 2-propeller shaft bushing, 3-sealing gasket 1, 4-end cover, 5-intermediate flange ring 1, 6-intermediate flange ring 2, 7-intermediate flange ring 3, 8-sealing gasket 2, 9-mounting flange ring, 10-gear box, 11-O-ring, 12-lip seal ring, 13-anti-mud and sand seal ring, 14-drive shaft, 15-drive shaft bushing, 16-dustproof ring, 17-lip seal ring, 18-sealing seat, 19-spacer, 20-pressure plate, 21-O-ring, 22-fastening screw. DETAILED DESCRIPTION

[0031] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0032] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0033] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present disclosure.

[0034] according to Figure 2 The working principle of the lateral thruster air sealing system is explained as follows: The compressed air on board is filtered, decompressed, and flow-regulated by the air control unit (C) before entering the annular cavity of the #2 / #3 seal ring of the propeller shaft seal (A). A portion of the air overcomes the tension of the #1 and #2 seal rings and the pressure of the seawater and is released into the seawater in the form of bubbles, while the other portion of the air enters the discharge unit (J) from the pipeline and is discharged into the air. According to the classical principles of physics, the pressure at any point below the water surface is proportional to the height from that point to the water surface, so the change in the ship's draft can be determined by detecting the air pressure. Any change in the ship's draft can be automatically tracked by the air control unit (C) and the output pressure and the oil pressure at the propeller shaft seal (A) can be automatically adjusted to prevent seawater from invading the lateral thruster and lubricating oil from leaking out of the ship.

[0035] The compressed air on board is filtered, decompressed and flow-regulated by the air control unit (C) before entering the propeller shaft seal oil tank (D). The propeller shaft seal lubricating oil pump unit (G) then delivers the oil in the propeller shaft seal oil tank (D) to the annular cavity of the #3 / #4 seal ring of the propeller shaft seal (A), and then returns to the propeller shaft seal oil tank (D). Because there is a certain height difference between the propeller shaft seal oil tank (D) and the propeller shaft, the pressure in the annular cavity of the #3 / #4 seal ring needs to be controlled to be greater than the pressure in the annular cavity of the #2 / #3 seal ring within 0.05MPa, which can effectively extend the service life of the #3 seal ring and the propeller shaft bushing.

[0036] The compressed air on board is filtered by the air control unit (C), decompressed, and the flow is adjusted. The air is then decompressed again by the flow restrictor before entering the thruster seal oil tank (F). The thruster lubricating oil pump unit (I) then delivers the oil from the thruster seal oil tank (F) into the thruster body, and then returns to the thruster seal oil tank (F). Because the air is decompressed by the flow restrictor before entering the thruster seal oil tank (F), the pressure in the thruster body can be controlled to be lower than the pressure in the #3 / #4 seal ring cavity of the propeller shaft seal (A). The pressure difference is controlled within 0.05MPa, which can effectively extend the service life of the #4 seal ring and the propeller shaft bushing.

[0037] The lubricating oil in the #5 / #6 chamber of the drive shaft seal (B) is the circulating oil provided by the drive shaft seal lubricating oil pump unit (H). There is a certain height difference between the drive shaft seal oil tank (E) and the drive shaft seal (B), which can control the pressure of the #5 / #6 chamber of the drive shaft seal (B) to be lower than the pressure in the thrust body, and the pressure difference is controlled within 0.05MPa; the height between the drive shaft seal oil tank (E) and the drive shaft seal (B) is about 2m to prevent the #6 seal ring from being subjected to excessive pressure.

[0038] Table 1 shows the pressure conditions of each sealing ring and sealing chamber.

[0039] Table 1 Pressure conditions of each sealing ring and sealing chamber (unit: MPa) ; Among them, the pressure difference refers to △P2=P2# ring air pressure-P1# ring sea water pressure; △P2=P3 / 4 lubricating oil pressure-P2 / 3 air pressure.

[0040] The above explains the working principle of the air sealing system and the pressure conditions of each sealing ring from the perspective of the overall sealing system. The following will introduce each part one by one.

[0041] Propeller shaft seal: The propeller shaft seal plays a dual role in preventing seawater from entering the lateral thruster and preventing the lubricating oil inside the thruster from leaking into the seawater. The propeller shaft seal uses an air sealing system, which can separate seawater and lubricating oil through the air chambers #1 / #2 and #2 / #3 formed by compressed air, and the compressed air is blown out continuously and stably, which minimizes the mutual contamination between seawater and oil, and plays a positive role in protecting the marine environment and reducing the lubricating oil consumption of shipping companies. At the same time, through the integrated design with the full-ship automatic monitoring system, the operating status of the seal can be monitored in real time to improve the reliability and stability of the thruster device.

[0042] like Figure 3The diagram shows the structure of the propeller shaft seal. The propeller shaft seal structure consists of a propeller shaft 1, a propeller shaft bushing 2, an end cover 4, intermediate flange rings 5, 6, 7, a mounting flange ring 9, sealing gaskets 3 and 8, a lip seal 12 and an O-ring 11. The bushing of the propeller shaft seal is installed on the hub by bolts, and is sealed with the hub by a sealing gasket 1 (3), and is sealed with the propeller shaft 1 by an O-ring 11; the mounting flange ring 9 is fixed to the gear box (10) of the lateral thruster by bolts, and is sealed with the gear box 10 by a sealing gasket 2 (8). There are four lip seals inside the propeller shaft seal, with #1, #2 and #4 sealing rings facing outward and #3 sealing ring facing inward. When used for the first time, the #1 / #2 and #2 / #3 sealing chambers are filled with grease. The anti-sand seal 13 is arranged on the outer ring of the lip seal 12.

[0043] Drive shaft seal: The drive shaft sealing system prevents lubricating oil from entering the thruster compartment. Since the sealing line speed of the drive shaft is relatively high, a sealing ring made of FKM material should be used. Figure 4 The figure shows the driving shaft sealing structure. The driving shaft sealing structure consists of a driving shaft drive 14, a moving shaft bushing 15, a dust ring 16, a lip seal 17, a sealing seat 18, a spacer 19, a pressure plate 20, an O-ring 21 and a set screw 22. The lip seal 17 is divided into two, #5 and #6, and the lip direction is toward the inside of the lateral thruster. The middle chamber of the #5 / #6 sealing ring is connected to the driving shaft sealing oil tank E and the driving shaft sealing oil pump unit H. Because the driving shaft sealing oil tank is located at a position of about 2m above the sealing ring, it can offset the pressure inside the thruster body on the #5 sealing ring, reduce the wear of the #5 sealing ring lip and the driving shaft bushing, and change the #6 sealing ring from traditional grease lubrication to oil lubrication. At the same time, the driving shaft sealing oil pump unit H can flush and filter out impurities in the chamber of the #5 / #6 sealing ring, effectively improving the operating conditions of the sealing rings #5 and #6, and can effectively improve the sealing effect of the sealing ring and extend its service life.

[0044] Air Control Unit: like Figure 5The schematic diagram of the air control unit is shown. The air source interface AP1 is connected to the filter F1 and the filter F2, the air inlet end of the filter F1 is connected to the valve V1, the air outlet end of the filter F2 is connected to the valve V2, the air source interface AP1 is connected to the pressure gauge P1 through the valve V10 and the valve V3; the valve V2 is connected to the conversion switch C1, the conversion switch C1 is connected to the flow meter FM1 through the pressure reducing valve R1 and then to the air flow controller FC1; the conversion switch C1 is connected to the flow meter FM2 through the pressure reducing valve R2 and then to the air flow controller FC2; the air flow controller FC1 and the air flow controller FC2 are connected Connected to shuttle valve S1 (the interfaces on both sides, whichever side has a higher pressure, the gas on that side flows to the middle channel); clean fresh water is connected to the three-way stopcock through valve V9, and the shuttle valve S1 is connected to pressure switch A1 (when the pressure is lower than the threshold, an alarm signal is sent to the PLC control) and pressure gauge P1 through valve V5 and valve V6 respectively. The shuttle valve S1 is connected to one end of the conversion switch C2 through valve V8, and the other end of the conversion switch C2 is connected to shuttle valve S2 and air relay AR1 respectively. S2 is connected to pressure gauge P5 through valve V12, and shuttle valve S2 is also connected to valve V11.

[0045] Its main functions are as follows: Filter the air from the shipyard: The air source of the air control unit is 6-10bar daily air, and its cleanliness cannot meet the use requirements of the propeller shaft seal. It needs to pass through two filters, F1 and F2, to filter out the moisture and impurities in the air. DP1 is a differential pressure indicator. The differential pressure indicator should be checked every day, and the pointer should be in the green area (pressure difference is less than 0.1MPa). If the differential pressure indicator enters the red area, the air filters F1 and F2 need to be cleaned: open the V10 valve, close V1 and V2, open the V3 valve to release the pressure in the filter and then close it, remove the filter element of the air filter and clean it with high-pressure air or fresh water. If it still cannot meet the use requirements after cleaning, the filter element should be replaced; after repair, reinstall the filter element, open the V1 and V2 valves, and close the V10 valve.

[0046] Adjust the air pressure: The pressure entering the sealing system can be controlled by adjusting the pressure reducing valves R1 and R2. The specific adjustment pressure range is determined according to the actual working conditions. If the pressure reducing valve R1 fails, the conversion switch C1 should be adjusted to the standby position and the pressure reducing valve R2 should be enabled.

[0047] Adjust the air flow: The air flow entering the sealing system can be adjusted to a reasonable range through the air flow controllers FC1 and FC2, and the real-time flow can be observed through the flow meters FM1 and FM2.

[0048] Providing air to the propeller shaft seal, propeller shaft seal oil tank, and lateral thruster seal oil tank: The air control unit supplies filtered, reduced-pressure air to the ring chamber of the #2 / #3 seal ring of the propeller shaft seal, the propeller shaft seal oil tank, and the lateral thruster seal oil tank.

[0049] Stability of control system pressure: Air relay AR1 is used to control the pressure supplied to the propeller shaft seal oil tank and the lateral thruster seal oil tank to be higher than the pressure supplied to the annular cavity or discharge unit of the #2 / #3 seal ring of the propeller shaft seal. If a fault occurs, the conversion switch C2 should be adjusted to the standby position to allow air to be transported from the pipeline behind the flow controller to the propeller shaft seal oil tank and the lateral thruster seal oil tank.

[0050] Provide clean fresh water for cleaning air pipelines: V9 provides the system with fresh water for cleaning air pipelines. When the pressure difference between the air control unit output pressure P4 and the discharge unit pressure P8 is greater than 0.03MPa, the three-way stopcock needs to be adjusted to the fresh water pipeline and the pipeline needs to be flushed with fresh water. The air pipeline can also be cleaned regularly.

[0051] Propeller shaft seal oil tank: like Figure 6 The diagram shows the principle diagram of the propeller shaft seal oil tank. The main functions of the propeller shaft seal oil tank are: ① to provide lubricating oil for the propeller shaft seal lubricating oil pump unit; ② to provide a certain pressure for the annular cavity of the #3 / #4 seal ring of the propeller shaft seal, so that its oil pressure is higher than the air pressure of the annular cavity of the #2 / #3 seal ring within the range of 0.05MPa, which greatly increases the service life of the #3 seal ring.

[0052] The propeller shaft sealing oil tank is also equipped with a safety valve SV1, a high air pressure alarm switch A2, a low air pressure alarm switch A3, and a high and low oil level alarm switch A4, which can avoid damage to the sealing system due to excessive pressure, and can promptly detect high or low liquid levels, eliminate hidden dangers in a timely manner, improve the reliability of the lateral thruster sealing operation, and ensure the safety of ship operation.

[0053] Drive shaft seal oil tank: like Figure 7 The figure shows the principle diagram of the drive shaft seal oil tank. The main functions of the drive shaft seal oil tank are: ① to provide lubricating oil for the drive shaft seal lubricating oil pump unit; ② to provide a certain pressure for the ring cavity of the #5 / #6 seal ring of the drive shaft seal, to offset part of the pressure inside the lateral thruster on the #5 seal ring, to reduce the wear of the #5 seal ring and the drive shaft bushing, to enhance its sealing performance and to extend its service life.

[0054] The drive shaft sealing oil tank is also equipped with an oil level high and low alarm switch A13. When the drive shaft #5 seal ring is damaged, the high liquid level switch alarms. When the drive shaft #6 seal ring is damaged, the low liquid level switch alarms. It can promptly detect and eliminate hidden dangers of oil leakage to ensure navigation safety.

[0055] Lateral thruster seal tank: like Figure 8 The figure shows the principle diagram of the lateral thruster sealing oil tank. The main functions of the lateral thruster sealing oil tank are: ① to provide lubricating oil for the lateral thruster lubricating oil pump unit; ② to offset part of the pressure of the #4 sealing ring of the propeller shaft seal, and through the action of the flow limiter, the pressure difference it receives is controlled within the range of 0.05MPa, thereby increasing its service life; ③ to serve as an expansion tank for the lateral thruster.

[0056] The lateral thruster sealing oil tank is also equipped with a flow limiter, a safety valve SV2, an air pressure high alarm switch A6, an air pressure low alarm switch A7, and an oil level high and low alarm switch A8. The air pressure high alarm switch A6 and the air pressure low alarm switch A7 are connected to the oil tank through valve V31 and valve V30 respectively. When necessary, the oil tank discharges the lubricating oil through the normally closed ball valve V32, thereby avoiding excessive pressure from damaging the sealing system, being able to promptly detect excessively high or low liquid levels, and promptly eliminate hidden dangers, thereby improving the reliability of the lateral thruster sealing operation and ensuring the safety of ship operation.

[0057] Propeller shaft seal oil pump unit: like Fig. 9 The diagram shows the principle diagram of the propeller shaft seal lubricating oil pump unit. The main functions of the propeller shaft seal lubricating oil pump unit are: ① Filter out impurities in the oil entering the annular cavity of the #3 / #4 seal ring of the propeller shaft seal; ② The cooler is usually connected to 36°C fresh water, which plays a cooling role when the lubricating oil temperature is high, and can heat the oil temperature when the seawater temperature is very low.

[0058] The propeller shaft seal lubricating oil pump unit is mainly composed of filter F3, motors M1 and M2, pumps PU1 and PU2, and lubricating oil cooler. The filter is equipped with a check valve D2 and a pressure differential transmitter A5. When the filter F3 is blocked, the pressure differential transmitter A5 sends an alarm signal, the check valve D2 opens, and the oil flows from the check valve D2 to the rear pipeline; pumps PU1 and PU2 are one for use and one for backup. When the pressure differential indicator DP2 exceeds the set value, the backup pump PU2 is enabled and will not affect the operation of the system. A check valve D5 is connected in parallel to the cooler. When the cooler is blocked, the oil will enter the propeller shaft seal through the check valve D5. At this time, close the ball valves V23 and V24 and remove the cooler for maintenance.

[0059] Drive shaft seal oil pump unit like Fig.10 The figure shows the principle diagram of the drive shaft seal lubricating oil pump unit. The main functions of the drive shaft seal lubricating oil pump unit are: ① filter out impurities in the oil entering the ring cavity of the #5 / #6 seal ring of the drive shaft seal; ② circulate the oil entering the drive shaft seal ring to reduce the operating temperature of the seal ring through natural heat dissipation.

[0060] The drive shaft seal lubricating oil pump unit is mainly composed of filter F6, motors M3 and M4, and pumps PU3 and PU4. The filter is equipped with a check valve D12 and a differential pressure transmitter A11. When the filter F6 is blocked, the differential pressure transmitter A11 sends an alarm signal, the check valve D12 opens, and the oil flows from the check valve D12 to the rear pipeline; pumps PU3 and PU4 are one for use and one for backup. When the pressure sensor A12 is lower than the set value, the backup pump PU4 is enabled and will not affect the operation of the system. Once the lubricating oil pump unit fails and cannot operate, the ball valve V48 can be opened manually to ensure the normal operation of the system.

[0061] Lateral thruster oil pump unit: like Fig.11 The figure shows the principle diagram of the lateral thruster oil pump unit. The main functions of the lateral thruster oil pump unit are: ① to filter out impurities in the oil inside the lateral thruster; ② to cool the lubricating oil inside the lateral thruster.

[0062] The lateral thruster oil pump unit is mainly composed of motors M5 and M6, pumps PU5 and PU6, oil coolers and duplex filters F4 and F5. Pumps PU5 and PU6 are used in parallel and standby. When the pressure sensor A10 is lower than the set value, the standby pump PU6 is activated and will not affect the operation of the system. The cooler is connected in parallel with a check valve D9. When the cooler is blocked, the oil will enter the lateral thruster through the check valve D9. At this time, close the ball valves V38 and V39 and remove the cooler for maintenance. The duplex filter is equipped with check valves D10 and D11 and a pressure differential transmitter A9. When the filter F4 is blocked, the pressure differential transmitter A9 sends an alarm signal, the check valve D10 opens, and the oil flows from the check valve D10 to the rear pipeline. At this time, the handle of the duplex filter should be switched to the other side, the filter F5 should be activated, and the filter element of the filter F4 should be removed for cleaning or replacement.

[0063] Drain collection unit: like Fig.12 The main functions of the bleed collection unit are: The oil and water leaked from the chamber of the propeller shaft seal #2 / #3 seal ring are collected through valve V54; the discharge collection unit includes a valve pressure gauge P8 connected through valve V55; Used to monitor the working condition of the propeller shaft seal: The flow controller installed in the discharge collection unit is used to control the flow of air in the discharge pipeline and ensure that the discharge pipeline is unobstructed. When seawater enters or lubricating oil leaks, it will be collected in the unit through the discharge pipeline and a high-level alarm will be issued to remind the engine management personnel that the working condition of the propeller shaft seal device is abnormal. The engine personnel should drain the oil and water in the discharge collection cabinet when the main engine is stopped.

[0064] Collect water for cleaning the air pipeline: open the discharge valve V56 of the discharge collection unit, switch the three-way stopcock of the air control unit to the fresh water pipeline, open the fresh water valve V9, and flush the pipeline with clean fresh water until the water flows out of the discharge valve V56 on the discharge collection unit. After cleaning, switch the three-way stopcock to the air pipeline side and close the discharge valve V56. Flushing can only be done when the main engine is stopped.

[0065] The above-mentioned lateral thruster air sealing system forms all the seals of the lateral thruster system into a whole by adding a lateral thruster sealing oil tank and a drive shaft sealing oil tank, so that the pressure on each seal can be controlled below 0.05MPa, which can effectively improve the sealing effect of the sealing ring and extend its service life.

[0066] The drive shaft seal lubricating oil pump unit was introduced, and the traditional drive shaft seal grease lubrication method was changed to oil lubrication. The oil can be circulated, which has the effect of heat dissipation and cooling, improves the working condition of the drive shaft seal ring, and introduces high and low liquid level sensors. Once a leak occurs, the fault can be discovered and eliminated in time.

[0067] A flow restrictor is added in front of the lateral thruster sealing oil tank to reduce the pressure on the drive shaft #5 seal ring, allowing it to use a common seal, reducing costs, and allowing the entire lateral thruster to adapt to deeper draft conditions, increasing its application range.

[0068] Combining the lateral thruster sealing oil tank with the lateral thruster lubricating oil pump unit streamlines the pipeline, allows the oil in the lateral thruster sealing oil tank to circulate, and continuously filters and cools the oil, thereby improving the operating conditions of the bearings and gears inside the lateral thruster and reducing the impact of shortening their service life due to oil contamination.

[0069] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A lateral thruster air sealing system, the system comprising: Propeller shaft seal, drive shaft seal, air control unit, lateral thruster seal oil tank, discharge collection unit, characterized in that the system also includes: Propeller shaft sealing oil tank, drive shaft sealing oil tank, propeller shaft sealing oil pump unit, drive shaft sealing oil pump unit, lateral thruster oil pump unit; The compressed air on board enters the propeller shaft seal oil tank after being filtered, decompressed and adjusted by the air control unit. Then the propeller shaft seal lubricating oil pump unit transports the oil in the propeller shaft seal oil tank to the annular cavity formed by the #3 / #4 sealing ring of the propeller shaft seal, and then returns to the propeller shaft seal oil tank; The compressed air on board is filtered by the air control unit, decompressed, and the flow is adjusted. The air is decompressed again by the flow restrictor and then enters the lateral thruster sealing oil tank. Then the lateral thruster lubricating oil pump unit transports the oil in the lateral thruster sealing oil tank into the lateral thruster body, and then returns to the lateral thruster sealing oil tank. The lubricating oil in the chamber formed by the #5 / #6 sealing ring of the drive shaft seal is provided by the circulating oil of the drive shaft seal lubricating oil pump unit. There is a height difference between the drive shaft seal oil tank and the drive shaft seal. The pressure of the chamber formed by the #5 / #6 sealing ring of the drive shaft seal is controlled to be lower than the pressure in the thrust body. The pressure difference is controlled within 0.05MPa.

2. A lateral thruster air sealing system according to claim 1, characterized in that: The propeller shaft sealing oil tank includes: a safety valve SV1, an air pressure high alarm switch A2 connected to the propeller shaft sealing oil tank through a valve V15, an air pressure low alarm switch A3 connected to the propeller shaft sealing oil tank through a valve V14, an oil level high and low alarm switch A4, and a relief valve V16.

3. A lateral thruster air sealing system according to claim 1, characterized in that: The chamber formed by the #5 / #6 sealing ring of the drive shaft seal B is connected to the drive shaft seal oil tank and the drive shaft seal lubricating oil pump unit; The drive shaft seal oil tank is equipped with an oil level high and low alarm switch A13. When the #5 seal ring of the drive shaft seal is damaged, the high level switch alarms. When the #6 seal ring of the drive shaft seal is damaged, the low level switch alarms. The drive shaft seal oil tank includes a drain valve V44.

4. A lateral thruster air sealing system according to claim 1, characterized in that: The propeller shaft seal lubricating oil pump unit includes: filter F3, motor M1 and motor M2, main pump PU1 and standby pump PU2, and the first lubricating oil cooler; the main pump PU1 and standby pump PU2 are connected in parallel; The filter F3 is equipped with a one-way valve D2 and a differential pressure transmitter A5. When the filter F3 is clogged, the differential pressure transmitter A5 sends out an alarm signal, the one-way valve D2 opens, and the oil flows from the one-way valve D2 to the subsequent pipeline. The main pump PU1 and PU2 are standby pumps. When the differential pressure indicator DP2 exceeds the set value, the standby pump PU2 is activated. A one-way valve D5 is connected in parallel to the first lubricating oil cooler. When the first lubricating oil cooler is blocked, the oil will enter the propeller shaft seal through the one-way valve D5. At this time, the ball valves V23 and V24 are closed, and the first lubricating oil cooler is removed for maintenance. Motor M1 is used to drive the PU1 main pump, and M2 is used to drive the PU2 standby pump; The upstream and downstream of the differential pressure indicator DP2 are connected in series with valves V18 and V22 respectively; The upstream and downstream of the PU1 main pump are connected in series with valve V20 and check valve D3 respectively; the upstream and downstream of the PU2 standby pump are connected in series with valve V19 and check valve D4 respectively; The first lubricating oil cooler is connected in series downstream of the main pump PU1. WI1 and WO1 of the first lubricating oil cooler are respectively the water inlet and the water outlet of the first lubricating oil cooler.

5. A lateral thruster air sealing system according to claim 1, characterized in that: The drive shaft seal lubricating oil pump unit includes: filter F6, motor M3 and motor M4, main pump PU3 and standby pump PU4; motor M3 is used to drive the main pump PU3, and M4 is used to drive the standby pump PU4; The filter F6 is equipped with a one-way valve D12 and a differential pressure transmitter A11. When the filter F6 is clogged, the differential pressure transmitter A11 sends out an alarm signal, the one-way valve D12 opens, and the oil flows from the one-way valve D12 to the subsequent pipeline; Downstream of the filter F6, the main pump PU3 and the standby pump PU4 are connected in parallel, the motor M3 is used to drive the main pump PU3, the motor M4 is used to drive the standby pump PU4, the upstream of the main pump PU3 is connected in series with the valve V47 and the downstream is connected in series with the check valve D13, the upstream of the standby pump PU4 is connected in series with the valve V46 and the downstream is connected in series with the check valve D14, the downstream of the main pump PU3 is connected to the pressure gauge P7 and the pressure difference transmitter A12 through the valve V49 and the valve V50 respectively, the pressure gauge P7 is used at the outlet of the drive shaft seal lubricating oil pump; The main pump PU3 and the backup pump PU4 are used in pairs, and when the pressure sensor A12 is lower than the set value, the backup pump PU4 is enabled, which will not affect the operation of the system. Once the lubricating oil pump unit fails and cannot operate, manually open the ball valve V48 to ensure the normal operation of the system.

6. A lateral thruster air sealing system according to claim 1, characterized in that: The lateral thruster oil pump unit includes: motor M5 and motor M6, main pump PU5 and standby pump PU6, second oil cooler and duplex filter F4 and filter F5; the upstream of duplex filter F4 and filter F5 is connected to the second oil cooler, the upstream and downstream of the second oil cooler are connected to ball valve V38 and ball valve V39, the upstream of ball valve V38 is connected to pressure sensor A10 and pressure gauge P6 through valve 37 and valve 36 respectively, and pressure gauge P6 is used to measure the pressure of the lateral thruster oil pump; the upstream of ball valve V38 is connected to main pump PU5 and standby pump PU6, the main pump PU5 and standby pump PU6 are connected in parallel, motor M5 is used to drive PU5 main pump, and M6 is used to drive PU6 standby pump; The upstream of main pump PU5 is connected in series with valve V35 and the downstream of it is connected in series with check valve D7; the upstream of standby pump PU6 is connected in series with valve V35 and the downstream of it is connected in series with check valve D7; The main pump PU5 and the backup pump PU6 are used as one for use and one for backup. When the pressure sensor A10 is lower than the set value, the backup pump PU6 is enabled and will not affect the operation of the system. The second lubricating oil cooler is connected in parallel with a one-way valve D9. When the second lubricating oil cooler is blocked, the oil will enter the lateral thruster through the one-way valve D9. At this time, close the ball valves V38 and V39, and remove the second lubricating oil cooler for maintenance. The duplex filter is equipped with a one-way valve D10, a one-way valve D11 and a pressure differential transmitter A9. When the filter F4 is blocked, the pressure differential transmitter A9 sends an alarm signal, the one-way valve D10 opens, and the oil flows from the one-way valve D10 to the rear pipeline. At this time, the handle of the duplex filter should be switched to the other side, the filter F5 should be enabled, and the filter element of the filter F4 should be removed for cleaning or replacement.

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