Propeller hub sealing structure and ship

Abstract

This invention provides a propeller hub sealing structure and a ship. The structure includes an inner pressure cover, which is fitted onto a bushing and has a clearance fit with both the bushing and the propeller. Its end face near the propeller is watertight via a radial sealing ring. An outer pressure cover is fitted onto a bushing outside the inner pressure cover and also has a clearance fit with both the bushing and the inner pressure cover. Its inner ring end near the inner pressure cover is sealed via an axial sealing ring between the contact surfaces of the outer pressure cover and the bushing, and between the outer pressure cover and the inner pressure cover. This invention optimizes the traditional sealing cover into a combination of an inner and outer pressure cover. By employing two independent steps to install the axial and radial sealing rings, the process is simplified, and the difficulty of simultaneous installation is reduced. Furthermore, by providing an inspection hole on the inner pressure cover, the sealing effectiveness can be checked without removing the pressure cover, simplifying daily maintenance and significantly improving safety.

Description

Technical Field

[0001] This invention relates to the field of ship structural design technology, and in particular to a propeller hub sealing structure and a ship. Background Technology

[0002] The most significant advantage of water-lubricated shafting systems compared to oil-lubricated systems is their environmental friendliness, completely eliminating the possibility of oil pollution in the ocean. However, when applied to water-lubricated shafting systems in steel-hulled marine vessels, special attention must be paid to the corrosive effects of seawater on forged steel components, and effective protection of the forged steel shaft surface is essential. The surface of the forged steel shaft should be protected from open seawater, as seawater is highly corrosive and can cause corrosion cracks and accelerated fatigue. Therefore, various methods are employed in the design to protect the forged steel shaft surface (e.g., bushings, epoxy coatings, etc.). The propeller end face is a special contact area; see appendix. Figure 1 The propeller hub and forged steel shaft are installed using a hydraulic push-in method. Since a tight seal between the hub and shaft sleeve is not possible, an installation gap is inevitable. The propeller and shaft sleeve also have a clearance fit. After installation, the propeller is in an open water environment. If effective sealing measures are not taken at the ends, seawater intruding into the gaps between the propeller and shaft will have very serious consequences, endangering the safety of the ship.

[0003] Existing technologies generally adopt the following forms:

[0004] 1. Type a, employing a push-in compression sealing ring, which, after axial compression, seals the clearance mating surface between the bushing and the gland. Watertightness is achieved radially through circumferential fastening screws and washers. Figure 2 As shown;

[0005] 2. Type b, using an obliquely pressed sealing ring, operates on a similar principle, such as... Figure 3 As shown;

[0006] The disadvantages of Type A and Type B are that they do not fully take into account the force changes of the propeller moving in the water. After a long period of operation, the deformation of the screw gasket sealing type on the radial end face may lead to seal failure.

[0007] 3. Type c, employing both axial and radial dual-seal rings, can improve the working conditions of types a and b, as described above. Figure 4 As shown.

[0008] Therefore, type c sealing glands are a popular choice, as they are expected to maintain a seal for a longer period. However, their disadvantage is that...

[0009] (1) Installation is relatively difficult, requiring alignment and installation to be completed simultaneously in both axial and radial directions, which is quite challenging.

[0010] (2) The installation requirements for the sealing ring are relatively high. Too tight or too loose will affect the sealing effect. It is difficult to check the actual sealing effect after installation. It can only be judged by the experience of the construction process to determine whether the predetermined requirements have been met.

[0011] (3) The materials of the sealing ring have a general service life, and the range of service life is generally quite wide. For safety reasons, it is necessary to inspect it regularly. After the sealing ring has been used for a certain period of time, it is impossible to check whether it is still effective. The sealing effect can only be checked by disassembling it. Once the sealing ring is disassembled, it cannot be reused by resetting it and must be replaced.

[0012] (4) Frequent disassembly and inspection will increase the gap between the devices and reduce the fit, which is not conducive to achieving a sealing state again. Summary of the Invention

[0013] In view of the above-mentioned problems existing in the prior art, the present invention provides a propeller hub sealing structure and a ship to solve the above-mentioned technical problems existing in the prior art, and achieve the purpose of convenient installation, controllable sealing effect, and convenient inspection without disassembling the device.

[0014] This invention provides a propeller hub sealing structure, comprising:

[0015] An inner pressure cover is fitted onto a bushing and has a clearance fit with the bushing and the propeller. A radial sealing groove is provided on the end face near the propeller, and a radial sealing ring is provided in the radial sealing groove. The inner pressure cover is pressed and fixed to the propeller by fastening screws, and the seal between the inner pressure cover and the contact surface of the propeller is achieved by pressing the radial sealing ring.

[0016] An outer pressure cover is fitted onto a bushing outside the inner pressure cover and has a clearance fit with the bushing and the inner pressure cover. An axial sealing groove is provided on the inner ring side near the end of the inner pressure cover, and an axial sealing ring is provided in the axial sealing groove. The outer pressure cover is pressed and fixed to the inner pressure cover by two fastening screws, and the sealing between the contact surfaces of the outer pressure cover and the bushing, and between the outer pressure cover and the inner pressure cover is achieved by obliquely pressing the axial sealing ring.

[0017] In one embodiment, the cavity between the inner pressure cover, propeller, and bushing is further sealed by filling it with grease after installation.

[0018] In one embodiment, the inner pressure cover has an inspection hole that connects the external space and the cavity after installation, and the inspection hole is watertight by means of a threaded plug.

[0019] In one embodiment, the inner pressure cover has a groove at the inner ring side opening of the inspection hole. The groove communicates with the cavity after installation and can increase the gap between the inner pressure cover and the bushing.

[0020] In one embodiment, the inspection holes are provided in two sets.

[0021] In one embodiment, two sets of inspection holes are respectively arranged at the upper and lower ends of the inner pressure cover.

[0022] In addition, this invention also provides a ship, characterized in that: the ship includes a propeller hub sealing structure as described in any embodiment of this invention.

[0023] Compared with the prior art, the beneficial effects of the propeller hub sealing structure and ship provided by the embodiments of the present invention are as follows:

[0024] 1. The embodiments of the present invention optimize the traditional sealing gland into a combination of an inner gland and an outer gland. By adopting two independent steps to install the axial sealing ring and the radial sealing ring, the process is simplified and the difficulty of synchronous installation is reduced.

[0025] 2. The embodiments of the present invention allow for the inspection of sealing effectiveness without removing the pressure cover by opening an inspection hole on the inner pressure cover. This makes daily maintenance simple and provides significant safety benefits. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the assembly relationship between the propeller and the forged steel shaft according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of the structure of type a involved in the background section of this invention;

[0028] Figure 3 This is a schematic diagram of the structure of type b involved in the background section of this invention;

[0029] Figure 4 This is a schematic diagram of the structure of type c involved in the background section of this invention;

[0030] Figure 5 This is a schematic diagram of a propeller hub sealing structure provided in an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of the main structure of the inner pressure cover involved in a propeller hub sealing structure provided in an embodiment of the present invention;

[0032] Figure 7 for Figure 6 Schematic diagram of the structure of section AA in the middle;

[0033] Figure 8 for Figure 6 Schematic diagram of the structure of the middle BB section;

[0034] Figure 9 This is a schematic diagram of the pipe thread plug involved in a propeller hub sealing structure provided in an embodiment of the present invention.

[0035] Figure label:

[0036] 1. Propeller; 2. Shaft; 3. Bushing; 4. Inner pressure cover; 5. Radial sealing groove; 6. Radial sealing ring; 7. First threaded hole; 8. Second threaded hole; 9. Groove; 10. Cavity after installation; 11. Outer pressure cover; 12. Axial sealing groove; 13. Axial sealing ring; 14. Fastening screw one; 15. Fastening screw two; 16. Inspection hole; 17. Pipe thread plug. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0039] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0040] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0041] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0042] Specific embodiments of this application are described below with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to ascertain the true intent based on the user's historical operations, and to avoid unnecessary or redundant details that would obscure this application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in various ways with substantially any suitable detailed structure.

[0043] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0044] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments described are for illustrative purposes only and are not intended to limit the scope of the invention. The following description, in conjunction with... Figure 1-9 The preferred embodiments of the present invention will be described in further detail below:

[0045] Generally designed end-face sealing caps use O-rings for sealing via top or oblique pressure, which theoretically achieves the desired sealing effect. However, this design also presents several problems: First, the installation requirements for the O-rings are relatively high; both excessive tightness and looseness will affect the sealing effect. Furthermore, it is difficult to check the actual sealing effect after installation in typical designs. Second, the materials used for O-rings have a generally wide service life, requiring regular inspection for safety. Typical designs can only check the sealing effect by disassembling the device. Once disassembled, the O-ring cannot be reused after a period of use and must be replaced. Third, frequent disassembly and inspection can increase the clearance between components, reduce the fit, and make it difficult to achieve and maintain a sealed state.

[0046] To solve the above technical problems, such as Figure 1-9 As shown, an embodiment of the present invention provides a propeller hub sealing structure, comprising:

[0047] An inner pressure cover 4 is sleeved on the bushing 3 and has a clearance fit with the bushing 3 and the propeller 1. A radial sealing groove 5 is provided on the end face near the propeller 1, and a radial sealing ring 6 is provided in the radial sealing groove 5. The inner pressure cover 4 is pressed and fixed on the propeller 1 by fastening screw 14, and the seal between the inner pressure cover 4 and the contact surface of the propeller 1 is achieved by pressing the radial sealing ring 6.

[0048] An outer pressure cover 11 is sleeved on the bushing 3 outside the inner pressure cover 4 and is clearance-fitted with the bushing 3 and the inner pressure cover 4. An axial sealing groove 12 is provided on the inner ring side near the end of the inner pressure cover 4, and an axial sealing ring 13 is provided in the axial sealing groove 12. The outer pressure cover 11 is pressed and fixed on the inner pressure cover 4 by fastening screws 15, and the sealing between the contact surfaces of the outer pressure cover 11 and the bushing 3, and between the outer pressure cover 11 and the inner pressure cover 4 is achieved by obliquely pressing the axial sealing ring 13.

[0049] The inner pressure cover 4 is provided with a first threaded hole 7 for installing fastening screw 14 and a second threaded hole 8 for installing fastening screw 2 15. The first threaded hole 7 is a through hole and the second threaded hole 8 is a countersunk hole. The first threaded hole 7 and the second threaded hole 8 are arranged at intervals and are arranged in a circular array on the inner pressure cover 4.

[0050] This embodiment of the invention retains the design of the axial sealing ring 13 and the radial sealing ring 6, which can maximize the sealing effect during ship operation. The inner sealing cover 4 is installed with screws and washers on the end face of the propeller 1, and the radial sealing ring 6 is embedded to enhance the long-term sealing effect. The outer sealing cover 11 adopts a traditional oblique pressure sealing method, which is convenient to install and has a good axial sealing effect. It is fastened to the inner sealing cover 4 by screws and washers. Because the axial sealing ring 13 and the radial sealing ring 6 are installed in two independent steps, the process is simplified and the difficulty of synchronous installation is reduced.

[0051] In one embodiment, the cavity 10 between the inner pressure cover 4, the propeller 1 and the bushing 3 is further sealed by filling it with grease. The purpose of filling with grease is to prevent the intrusion of external seawater by using pressurized grease, which is the last protection before the seawater comes into contact with the surface of the forged steel shaft 2.

[0052] In one embodiment, the inner pressure cover 4 has an inspection hole 16 that connects the external space and the cavity 10 after installation, and the inspection hole 16 is watertight by means of a threaded plug 17.

[0053] In one embodiment, the inner pressure cover 4 is provided with a groove 9 at the inner ring side opening of the inspection hole 16. The groove 9 communicates with the cavity 10 after installation and can increase the gap between the inner pressure cover 4 and the bushing 3.

[0054] In one embodiment, the inspection hole 16 is provided in two sets.

[0055] Furthermore, in one embodiment, two sets of inspection holes 16 are respectively arranged at the upper and lower ends of the inner pressure cover 4.

[0056] That is, holes are drilled at both ends of the inner sealing cover 4 to reach the cavity 10 after installation, and a pipe thread plug 17 is used to achieve watertightness. There are three purposes for drilling holes: first, the upper hole can be used for grease filling after the initial installation; second, the lower hole can be used for venting during later inspection; third, the upper and lower holes can be used for endoscopy, to inspect the cavity 10 after the propeller 1 is installed by inserting a sensor, and even consider the possibility of installing a water immersion sensor or other subsequent applications. When checking the vent plug, if seawater flows out, it means that the sealing ring has failed. At this time, the sealing ring needs to be removed and the shaft system needs to be further inspected. If no seawater flows out, it means that the sealing of the device is intact. If the sealing ring material is still within its validity period, disassembly and replacement can be avoided.

[0057] The inner pressure cover 4 and the outer pressure cover 11 are sealed with a gap from the bushing 3 to facilitate actual on-site installation. At the inspection hole 16 position of the inner pressure cover 4, the gap should be increased to facilitate the flow of grease injection and the insertion of the endoscope sensor during inspection.

[0058] In addition, embodiments of the present invention also provide a propeller hub sealing device, the device comprising an inner pressure cover 4 and an outer pressure cover 11 as described in any embodiment of the present invention.

[0059] In addition, this invention also provides a ship, which includes a propeller hub sealing structure as described in any embodiment of this invention.

[0060] This busy implementation has the following beneficial effects:

[0061] 1. The parts are designed simply and are easy to manufacture;

[0062] 2. Simplify the installation process and reduce installation difficulty;

[0063] 3. Simple daily maintenance and significant safety benefits.

[0064] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A propeller boss seal structure, characterised in that, include: An inner pressure cover (4) is fitted on the bushing (3) and has a clearance fit with the bushing (3) and the propeller (1). A radial sealing groove (5) is provided on the end face near the propeller (1), and a radial sealing ring (6) is provided in the radial sealing groove (5). The inner pressure cover (4) is pressed and fixed on the propeller (1) by a fastening screw (14), and the seal between the inner pressure cover (4) and the contact surface of the propeller (1) is achieved by pressing the radial sealing ring (6). An outer pressure cover (11) is fitted on the bushing (3) outside the inner pressure cover (4) and has clearance fit with the bushing (3) and the inner pressure cover (4). An axial sealing groove (12) is provided on the inner ring side near the end of the inner pressure cover (4), and an axial sealing ring (13) is provided in the axial sealing groove (12). The outer pressure cover (11) is pressed and fixed on the inner pressure cover (4) by fastening screws (15), and the sealing between the contact surfaces of the outer pressure cover (11) and the bushing (3) and the inner pressure cover (4) is achieved by obliquely pressing the axial sealing ring (13). The cavity (10) between the inner pressure cover (4), the propeller (1) and the bushing (3) after installation is further sealed by filling with grease; The inner pressure cover (4) is provided with an inspection hole (16) that connects the external space and the cavity (10) after installation, and the inspection hole (16) is watertight by means of a threaded plug (17) of a threaded pipe. The inner pressure cover (4) has a groove (9) at the inner ring side opening of the inspection hole (16). The groove (9) is connected to the cavity (10) after installation and can increase the gap between the inner pressure cover (4) and the bushing (3).

2. A propeller hub seal structure according to claim 1, wherein: The inspection hole (16) is provided in two sets.

3. The propeller hub sealing structure according to claim 2, characterized in that: Two sets of inspection holes (16) are respectively located at the upper and lower ends of the inner pressure cover (4).

4. A ship, characterized in that: The vessel includes a propeller hub sealing structure as described in any one of claims 1-3.

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