A quick repair method for rudder stock stuffing box flange leakage

Abstract

The application discloses a rudder stock stuffing box flange water leakage quick repairing method, which comprises the following steps: disassembling the stuffing box gland and the stuffing box body, cleaning the sealing surface of the stuffing box body and the ship base to expose the corrosion area; filling silica gel in the area, and setting a gasket sealing structure between the stuffing box body and the ship base, wherein water-sensitive resin and thermosetting resin can be added to the silica gel to enhance the active compensation and structural stability of the sealing; for the deep corrosion area, a filling groove can be formed and the thermosetting resin and silica gel can be filled in layers; after the stuffing box body is updated and reset, a radial abutting positioning structure is arranged along the outer side of the stuffing box body to realize the axis centering; and finally, the stuffing box body and the gland are closed. Through material combination and structure positioning, the method can effectively adapt to the dynamic deformation of the ship body and realize quick and durable sealing repair.

Description

Technical Field

[0001] This invention relates to the field of ship maintenance technology, specifically to a method for rapid repair of leaks in the rudder stock stuffing box flange. Background Technology

[0002] The rudder stock is the core drive shaft for rotating the rudder blades. Its upper end connects to the steering gear transmission mechanism, and its lower end passes through the rudder stock cylinder in the hull and is fixed to the rudder blades. Its function is to transmit the torque of the steering gear to the rudder blades, thereby controlling the ship's course and ensuring maneuverability. Since the rudder stock needs to pass through the hull plating, this passage is equipped with a stuffing box sealing device, which typically consists of a gland, stuffing, and a box body. Tightening the stuffing achieves a dynamic seal between the rudder stock and the hull, preventing seawater from entering the compartment.

[0003] In actual operation, especially under full-load navigation conditions, the stress and deformation of the hull, as well as the continuous vibration and rotation of the rudder stock, can easily lead to fretting displacement and gaps between the stuffing box body and the welded base flange of the hull. Over long-term operation, seawater continuously leaks between the stuffing box flange and the hull flange. Traditional methods such as tightening bolts and welding set screws only attempt to strengthen the rigidity of the flange face, but they are insufficient to compensate for the dynamic deformation of the hull structure and the permanent crushing failure of the gaskets, thus proving ineffective and failing to completely eliminate the leakage.

[0004] Therefore, there is an urgent need for a maintenance and reinforcement technology that can adapt to dynamic operating conditions and effectively and sustainably resolve the leakage at this location. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for treating water leakage in the rudder stocking gland flange, thereby solving the problems described in the background art.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows.

[0007] A method for quickly repairing leaks in the rudder stocking gland flange includes the following steps: S10. Disassemble the stuffing gland cover and stuffing gland body; S20. Clean the sealing mating surfaces between the stuffing box and the hull base to expose the corroded areas; S30. A gasket sealing structure is provided between the stuffing box and the hull base, and silicone is filled in the corroded area. S40. Update the stuffing box and reset it to the hull base. On the hull base, a corresponding positioning structure is provided along the outer circumference of the stuffing box. The positioning structure is radially pressed against the stuffing box so that the rudder stock is aligned with the axis of the stuffing box.

[0008] S50. Fully seal the stuffing box body and the stuffing box cover.

[0009] As a preferred technical solution, step S10 includes at least one of the following steps: S11. Apply rust remover to the contact surface between the stuffing gland cover and the stuffing gland body; S12. Weld an auxiliary pull-out plate to the outer surface of the stuffing box cover and apply a lifting force to the auxiliary pull-out plate; S13. Bake or heat the outside of the stuffing box cover.

[0010] As a preferred technical solution, step S20 includes at least one of the following steps: S21. Remove residual corrosion from the sealing mating surface using physical methods; S22. Use chemical methods to remove residual corrosion from the sealing mating surfaces.

[0011] As a preferred technical solution, step S30 includes at least one of the following steps: S31. The filling thickness of the silicone is not less than 3mm, and it completely covers the corroded area and extends 10-15mm to the periphery; S32. Install metal sealing gaskets at the flange fixing bolts.

[0012] As a preferred technical solution, step S30 further includes S33, adding a water-sensitive resin with a mass ratio of 5%–15% to the silicone, wherein the water-sensitive resin is a polyurethane prepolymer or an acrylic water-absorbing resin.

[0013] As a preferred technical solution, step S30 further includes S34, adding 8%–20% by mass of a thermosetting resin to the silicone, wherein the thermosetting resin is one of epoxy resin, unsaturated polyester resin or phenolic resin.

[0014] As a preferred technical solution, step S30 further includes S35: for corrosion areas with a depth greater than 2mm, removing the corrosion area along its contour to form a regular filling groove.

[0015] As a preferred technical solution, in step S35, before the filling operation, the groove area is preheated, a thermosetting resin layer is filled into the preheated area and allowed to initially cure, and the silicone is covered on the surface of the thermosetting resin layer.

[0016] As a preferred technical solution, in step S40, the positioning structure includes wedge blocks, which are uniformly distributed along the circumference of the stuffing box.

[0017] As a preferred technical solution, in step S40, the positioning structure is a closed ring surrounding the outer periphery of the packing gland; the closed ring is made of sacrificial anode material and is electrically connected to the hull base.

[0018] The advantages and beneficial effects of this invention are as follows: It provides a rapid repair method for leaking rudder stocking gland flanges. First, the mating surfaces are disassembled and cleaned. Then, silicone is filled into the corroded area, with a water-sensitive resin and a thermosetting resin specifically incorporated into the silicone. The water-sensitive resin expands upon contact with water, self-compensating for microscopic leakage paths, while the thermosetting resin forms a stable support structure through curing, enhancing the packing's durability and pressure resistance. Furthermore, regular grooves are created and layered filling is applied to deeply corroded areas, further improving the bonding strength and deformation resistance of the repair interface. During the structural repositioning stage, radial clamping and axial alignment are achieved by setting positioning structures, such as wedges or sacrificial anode sealing rings, around the circumference of the stuffing gland body, suppressing micro-displacements caused by hull deformation. The combination of flexible sealing and rigid positioning adapts to vibrations and deformations during ship operation.

[0019] The overall process shown in this invention emphasizes process integration and material matching, which can shorten the maintenance cycle and reduce the impact on ship operation while ensuring reliable repair. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below. It is to be understood that the specific embodiments described herein are merely illustrative of this application and not intended to limit it. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0021] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly or implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] This invention provides a method for rapid repair of leaking rudder stock stuffing box flanges, the method comprising the following steps: S10. Disassemble the stuffing gland cover and stuffing gland body; S20. Clean the sealing mating surfaces between the stuffing box and the hull base to expose the corroded area; S30. Install a gasket sealing structure between the stuffing box and the hull base, and fill the corroded area with silicone. S40. Update the stuffing box and reset it to the hull base. On the hull base, a positioning structure is provided along the outer circumference of the stuffing box. The positioning structure radially abuts against the stuffing box, so that the rudder stock is aligned with the axis of the stuffing box. S50. Seal the stuffing box body and stuffing box cover.

[0024] Because ships operate in seawater environments for extended periods, the connection between the stuffing box gland and the stuffing box body often becomes sticky due to rust, biofouling, and aging of the sealing material. Direct disassembly can easily damage the components. Therefore, step S10 can employ various auxiliary methods to safely and efficiently complete the disassembly. For example, a rust remover can be sprayed onto the contact surface between the gland and the stuffing box body. This remover, through penetration and lubrication, breaks down the bond between the rust layer and the metal substrate, reducing disassembly resistance. Alternatively, an auxiliary pull plate can be welded to the outer surface of the gland. Controllable lifting force can be applied using external lifting equipment, utilizing the lever principle to gradually separate the gland, avoiding localized stress concentration that could lead to component deformation. Localized heating can also be applied to the outside of the gland, utilizing the thermal stress generated by the difference in thermal expansion coefficients between the metal and the sealing material to promote interface separation. These auxiliary methods can be used individually or in combination, with the aim of achieving component separation in a non-destructive manner, creating conditions for subsequent cleaning and repair.

[0025] Step S20 thoroughly removes old sealing material, corrosion products, oil stains, and marine organism residue from the sealing mating surfaces, creating a clean and activated metal surface to ensure adequate wetting and adhesion of subsequent sealing materials. Cleaning can be achieved using a combination of physical and chemical methods. Physical methods, such as using wire brushes, sandpaper, or sandblasting, mechanically remove surface deposits and loose corrosion layers. Chemical methods utilize mild acidic or neutral cleaning agents to dissolve metal oxides and salt deposits through chemical reactions. Special care must be taken to protect the base metal in non-corroded areas during cleaning to avoid excessive material removal that could compromise structural strength. Thoroughly exposing the corroded areas helps in accurately assessing the extent of damage.

[0026] Step S30 involves installing a gasket sealing structure between the stuffing box and the hull base, and simultaneously filling the corroded area with silicone.

[0027] First, a gasket sealing structure is installed between the stuffing box and the flange mating surface of the hull base. Its function is to compensate for the micro gaps caused by the loosening of bolt preload or permanent deformation of the gasket, and to rebuild the seal of the flange surface. Metal sealing gaskets are preferred because they have good resilience and creep resistance and can maintain a certain sealing pressure under dynamic loads.

[0028] Secondly, silicone is used to fill the corroded areas exposed after cleaning. Silicone has excellent flexibility, seawater corrosion resistance, and wide temperature range stability, making it an ideal filling material for dynamic sealing interfaces. Its filling thickness is not less than 3mm, completely covering the corroded area and extending 10-15mm outwards to form a flexible seal with a certain thickness and area, which can absorb and compensate for the interface fretting caused by hull deflection and rudder vibration.

[0029] To further enhance the adaptability and durability of silicone sealing systems in harsh marine environments, this invention introduces functionalized components into the silicone matrix.

[0030] In some embodiments, to endow the sealing material with the ability to actively respond to leaks, a water-sensitive resin, such as a polyurethane prepolymer or an acrylic water-absorbing resin, is added to the silicone at a mass ratio of 5%–15%. These resin molecules are rich in hydrophilic groups. In a dry state, they form a homogeneous composite material with the silicone. Upon the infiltration of even a small amount of seawater, water molecules are rapidly absorbed by the water-sensitive resin, causing its molecular chains to swell and its volume to expand in a controlled manner. The inward pressure generated by this expansion can, in real time and autonomously, seal newly created microscopic leakage channels caused by dynamic deformation, achieving self-healing of the sealing interface.

[0031] In other embodiments, to enhance the structural support and long-term crush resistance of the filler, 8%–20% by weight of a thermosetting resin, such as epoxy resin, unsaturated polyester resin, or phenolic resin, can be added to the silicone. During curing, the thermosetting resin forms a three-dimensional cross-linked network structure, creating an interpenetrating or semi-interpenetrating polymer network with the silicone's elastomeric network. This composite structure combines the elasticity of silicone with the rigidity of thermosetting resin, significantly improving the filler's modulus, resistance to compression set, and resistance to media penetration. When the stuffing box flange is subjected to bolt tightening force and compressive stress transmitted from the hull structure, the composite filler is less prone to irreversible plastic deformation, thus maintaining long-term sealing pressure stability.

[0032] For corroded areas with a depth greater than 2 mm, simple surface filling is insufficient to guarantee bonding strength and long-term reliability.

[0033] To address this, the repair solution provided by this invention includes: First, machining along the contour of the corroded area to remove all corroded material, forming a regular filling groove with clean sidewalls; eliminating the weak interface layer and providing a good mechanical interlocking basis for new materials. Before filling, the groove area can be preheated to remove adsorbed moisture, increase the surface energy of the substrate, and facilitate the flow and wetting of subsequent filling materials. After preheating, a layer of thermosetting resin is filled into the bottom of the groove and allowed to partially cure. This thermosetting resin layer restores the lost metal structural strength of the corroded area, providing a robust and stable base. Subsequently, the aforementioned silicone layer is covered on the surface of the thermosetting resin layer. The lower layer of this structure is responsible for bearing and restoring the structure, while the upper layer is responsible for dynamic sealing and compensation.

[0034] Step S40: Update the stuffing box and reset it to the hull base. On the hull base, a positioning structure is set along the circumferential direction of the outer side of the stuffing box. The positioning structure radially abuts against the stuffing box, aligning the rudder stock with the axis of the stuffing box. This addresses the problem that traditional repairs often result in the stuffing box slightly shifting under dynamic conditions due to a lack of effective radial constraint, thus damaging the newly formed sealing interface. After resetting and updating the stuffing box, a controllable radial abutment force is applied to the stuffing box by setting a circumferential positioning structure on the hull base, forcing it to remain concentric with the rudder stock.

[0035] In some embodiments, the positioning structure employs a plurality of wedge-shaped blocks evenly distributed circumferentially along the stuffing box. A uniform and adjustable radial clamping force is generated by synchronously striking or hydraulically driving the wedge-shaped blocks to move towards the center.

[0036] In some preferred embodiments, the positioning structure employs a complete closed ring surrounding the outer periphery of the stuffing box. This closed ring is made of a sacrificial anode material (such as zinc alloy) and is electrically connected to the steel hull base by welding or conductive adhesive. On the one hand, the closed ring provides a rigid constraint to the stuffing box in the entire circumference through interference fit or bolt tightening, resulting in better centering; on the other hand, as a sacrificial anode, it preferentially corrodes in the seawater electrolyte environment, and the released protective current makes the connected hull base and stuffing box act as cathodes, thereby effectively protecting them and slowing down the electrochemical corrosion rate of this critical connection area.

[0037] Step S50: Seal the stuffing box body and stuffing box cover. After confirming that the stuffing box body is accurately positioned and sealed and filled, install and tighten the stuffing box cover according to the standard operating procedure to complete the reassembly of the entire stuffing box device.

[0038] Based on the core solutions described above, adaptive adjustments can be made according to site conditions, the degree of damage, and maintenance resources. For example, in step S30, the modification of the silicone can be achieved by adding a single or compound of water-sensitive / thermosetting resins depending on the leaking medium and temperature range. For areas with shallow corrosion, modified silicone can be used directly for filling, without the need for grooving or thermosetting resin underlayment. In step S40, in addition to wedge blocks and sacrificial anode rings, an adjustable radial setter array can also be considered for the positioning structure, but care must be taken to avoid local stress concentration. All operations should follow safety regulations, especially when involving thermal operations such as welding and heating, where effective isolation of surrounding flammable materials is required.

[0039] In summary, the rapid repair method for leaking rudder stock stuffing box flange provided by this invention, through the process of disassembly and cleaning, functional sealing and filling, and precise positioning and alignment, not only achieves rapid sealing of leaks, but also improves the durability and reliability of the repair from multiple dimensions such as suppressing micro-displacement, compensating for dynamic deformation, and enhancing corrosion resistance. It effectively overcomes the limitations of traditional rigid repair methods and is suitable for rapid maintenance and support of ships during navigation or docking.

[0040] Traditional methods, such as repeatedly tightening bolts, welding top screws, or replacing gaskets and relying solely on bolt tightening, typically require a long period of repeated adjustments and observations. Because these methods are difficult to adapt to dynamic deformations of the hull, leaks often reappear within a short period of time (e.g., several hours to several days) due to vibrations or minor structural movements after repair. This means that maintenance work may need to be repeated, resulting in a long overall effective repair cycle, during which the ship's maneuverability is limited or its speed needs to be reduced.

[0041] The method of this invention ensures resetting accuracy by setting a radial positioning structure, avoiding repeated centering adjustments. The entire repair process can be completed in one operation, effectively shortening the repair time and quickly restoring the ship to normal operating conditions.

[0042] Regarding repair effectiveness, traditional methods essentially attempt to force a seal by reinforcing rigid connections, which has limitations. First, they cannot compensate for flange separation and fretting caused by changes in hull load. Second, existing corroded areas are not specifically treated, creating weak points in the seal. Furthermore, the lack of effective radial alignment and constraint allows the stuffing box to easily shift during vibration, compromising the seal. Therefore, the repair effects of traditional methods are usually temporary and unstable, with leaks prone to recurrence and difficult to eradicate completely.

[0043] This invention not only fills existing gaps, but its flexibility also absorbs dynamic deformation. The water-sensitive resin's water-swelling property actively compensates for microscopic leakage paths, achieving adaptive sealing under dynamic operating conditions. For corroded areas, structured repair is achieved through regularized grooving combined with a thermosetting resin layer, restoring interface strength. A circumferential positioning structure radially clamps and centers the stuffing box, effectively suppressing fretting displacement caused by vibration. This mechanical structure ensures the long-term stability of the sealing interface, and no failures were observed during a 180-day trial run.

[0044] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for rapid repair of leakage in a rudder stocking gland flange, characterized in that, Includes the following steps: S10. Disassemble the stuffing gland cover and stuffing gland body; S20. Clean the sealing mating surfaces between the stuffing box and the hull base to expose the corroded areas; S30. A gasket sealing structure is provided between the stuffing box and the hull base, and silicone is filled in the corroded area. S40. Update the stuffing box and reset it to the hull base. On the hull base, a positioning structure is provided along the outer circumference of the stuffing box. The positioning structure radially abuts against the stuffing box, so that the rudder stock is aligned with the axis of the stuffing box. S50. Seal the stuffing box body and stuffing box cover.

2. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 1, characterized in that, Step S10 includes at least one of the following steps: S11. Apply rust remover to the contact surface between the stuffing gland cover and the stuffing gland body; S12. Weld an auxiliary pull-out plate to the outer surface of the stuffing box cover and apply a lifting force to the auxiliary pull-out plate; S13. Bake or heat the outside of the stuffing box cover.

3. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 1, characterized in that, Step S20 includes at least one of the following steps: S21. Remove residual corrosion from the sealing mating surface using physical methods; S22. Use chemical methods to remove residual corrosion from the sealing mating surfaces.

4. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 1, characterized in that, Step S30 includes at least one of the following steps: S31. The filling thickness of the silicone is not less than 3mm, and it completely covers the corroded area and extends 10-15mm to the periphery; S32. Install metal sealing gaskets at the flange fixing bolts.

5. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 1 or 4, characterized in that, Step S30 further includes: S33. Add 5%-15% by weight of water-sensitive resin to the silicone, wherein the water-sensitive resin is a polyurethane prepolymer or an acrylic water-absorbing resin.

6. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 1, 4, or 5, characterized in that, Step S30 further includes: S34. Add 8%-20% by weight of thermosetting resin to the silicone, wherein the thermosetting resin is one of epoxy resin, unsaturated polyester resin or phenolic resin.

7. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 1, characterized in that, Step S30 further includes: S35. For corrosion areas with a depth greater than 2mm, remove the corrosion area along its contour to form a regular filling groove.

8. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 7, characterized in that, Before the filling operation in step S35, the groove area is preheated, a thermosetting resin layer is filled into the preheated area and allowed to initially cure, and the silicone is covered on the surface of the thermosetting resin layer.

9. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 1, characterized in that, The positioning structure in step S40 includes wedge-shaped blocks, which are uniformly distributed along the circumference of the stuffing box.

10. The method for rapid repair of leakage in the rudder stock stuffing box flange according to claim 1, characterized in that, The positioning structure in step S40 is a closed ring surrounding the outer periphery of the packing gland; the closed ring is made of sacrificial anode material and is electrically connected to the hull base.