Method for disassembling and assembling controllable-pitch propeller blades in marine guide pipe

Abstract

According to the method for disassembling and assembling the controllable-pitch propeller blade in the marine guide pipe, the gap between the propeller blade and the guide pipe is ingeniously utilized, and the huge difference between the weight of the propeller blade and the structural stability of the propeller is utilized, so that the propeller blade can be separated from the propeller based on self-weight inertia after a propeller hub flange bolt is disassembled; therefore, the blades can be detached. By means of the technical scheme, the blades can be disassembled and assembled without disassembling the whole tail shaft system in the prior art, capital consumption of shipyloads and shipyards is reduced, ship maintenance time is saved, equipment loss is reduced, the service life of equipment is prolonged, and personnel investment is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of installation and maintenance of controllable pitch propeller for ships, in particular, to a method for dismounting and mounting controllable pitch propeller blades in a duct of a ship. BACKGROUND

[0002] It is known that the propeller of a large ship itself can weigh tens of tons or even hundreds of tons, and the diameter can reach several meters or even tens of meters, which is a huge and heavy component. Dismounting the propeller blades of a ship is a complex and challenging engineering operation. In the prior art, all the dismounting and mounting of the blades requires disassembling the entire propeller shaft: 1. Dismounting the flange bolts, the flange bolts and bolt holes are precisely matched, and multiple mounting of the flange bolts will cause the bolts and bolt holes to be rough, which requires re-tapping and replacement of new bolts. 2. The hydraulic coupling needs to be dismounted, and multiple dismounting and mounting of the hydraulic coupling will cause the inner hole of the hydraulic coupling and the outer diameter of the shaft end to be rough, and in severe cases, the hydraulic coupling needs to be scrapped. 3. The entire stern shaft is pulled out of the ship body, and a large amount of manpower is required during the pulling-out process. At the same time, the internal accessories of the stern shaft, such as the internal oil pipe and the stern pipe bearing, may be damaged during hoisting. Safety risks may also occur during hoisting. 4. After pulling out the entire stern shaft, a separate tool holder needs to be made to mount the propeller on the holder above the stern shaft for dismounting and mounting the blades. The above conventional dismounting and mounting of the blades has certain technical difficulties and a considerable amount of engineering, which requires a large amount of funds and manpower.

[0003] With the development of ship technology, most ship owners have begun to choose advanced controllable pitch propellers, full rotation controllable pitch propellers and controllable pitch propeller side thrusts. However, these devices are all equipped with ducts, therefore, it is particularly valuable to study a method for dismounting and mounting controllable pitch propeller blades in a duct of a ship. SUMMARY

[0004] In view of the defects in the prior art, the purpose of the present application is to provide a method for dismounting and mounting controllable pitch propeller blades in a duct of a ship. The purpose of this dismounting and mounting method is to dismount and mount the blades without dismounting the entire stern shaft system as in the prior art, to reduce the consumption of funds by ship owners and shipyards, to save ship maintenance time, to reduce equipment wear and tear and increase equipment service life, and to reduce personnel input.

[0005] According to the method for dismounting and mounting controllable pitch propeller blades in a duct of a ship provided by the present application, the dismounting of the blades comprises the following steps:

[0006] Step 1: preparing a hoisting tool for hoisting the propeller blades; adjusting the propeller blades to a certain pitch position so that a distance is left between the propeller and the duct to allow the propeller to be separated from the duct;

[0007] Step 2, loosen the bolts at the hub flange, turn the blade to be removed to a certain orientation to facilitate the blade to be removed from the hub flange;

[0008] Step 3, insert a spacer under the blade to be removed to fix the blade position and ensure that the blade will not rotate and overturn; wrap several lifting belts around the blade flange, and hang the lifting belts on the lifting tool through the hoist;

[0009] Step 4, remove the spacer, slowly loosen the hoist, and let the blade slowly separate from the hub flange by its own weight;

[0010] Step 5, remove the other blades in sequence according to the above steps until all the blades are removed.

[0011] Further, before removing the wedge in step 4, the hydraulic oil inside the hub is released.

[0012] Further, the pitch position is the zero pitch position.

[0013] Further, the lifting tool has a weight greater than 1.5 times the weight of the blade.

[0014] Further, the lifting tool is a lifting ring welded on the hull.

[0015] Further, the lifting belt has a weight greater than 1.5 times the weight of the blade.

[0016] Further, the spacer is a wedge customized according to the size of the blade.

[0017] Further, the orientation in step 2 is the 6 o'clock direction.

[0018] Further, the hoist has a weight greater than 1.5 times the weight of the blade.

[0019] Further, the steps of installing the blade in the duct are performed in reverse order of the steps of removing the blade, as follows:

[0020] Step 1: Wrap several lifting belts around the flange of the blade to be installed, and hang the lifting belts on the lifting tool through the hoist;

[0021] Step 2: Turn the hub flange of the blade to be installed to a certain orientation, slowly tighten the hoist, and slowly fit the blade to the hub flange;

[0022] Step 3: After the blade is completely inserted into the hub flange, insert a spacer under the blade to fix the blade position and ensure that the blade will not rotate and overturn;

[0023] Step 4: Tighten the bolts at the hub flange to complete the installation of the blade.

[0024] Step five: install other blade blades in turn according to the above steps until all the blades of the paddle are installed.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] 1. The present application does not need to disassemble the entire tail shaft system to disassemble the paddle, has low requirements for the operating environment, does not require high technical requirements for engineers, and has strong adaptability.

[0027] 2. The operation steps of the present application are simple and have strong reproducibility, the auxiliary tools used are easily obtained at the ship berth, do not require a large amount of investment, save ship maintenance time, reduce equipment damage and increase equipment use.

[0028] 3. The present application ingeniously utilizes the gap between the paddle and the duct, and the huge difference between the weight of the paddle blade and the stability of the propeller structure, so that the paddle blade can be separated from the propeller based on the weight inertia after the propeller flange bolt is disassembled, thereby realizing the disassembly of the paddle. BRIEF DESCRIPTION OF DRAWINGS

[0029] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings:

[0030] Figure 1 The present application is a method for disassembling and assembling a propeller blade in a ship duct.

[0031] Figure 2 The present application is a structure diagram of a controllable pitch propeller hub. DETAILED DESCRIPTION

[0032] The present application will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of changes and improvements can be made. These all belong to the protection scope of the present application.

[0033] The present application provides a method for disassembling and assembling a propeller blade in a ship duct, which includes the following steps:

[0034] Step 1: Prepare the lifting tools for suspending the propeller blades; adjust the propeller blades to a specific pitch position, ensuring sufficient distance between the blades and the guide tube for the blades to detach from the guide tube. Specifically, the pitch position is preferably zero pitch. Specific operation: Turn on the hydraulic pump station, operate the pitch control valve, and align the 0-mark line on the blade with the 0-mark line on the propeller hub. At this point, the pitch position is zero pitch. Because the propeller blades are irregularly shaped, their diameter changes with the propeller angle. Generally, the blade diameter is smallest and the gap with the guide tube is largest at zero pitch, providing sufficient distance for the blades to detach from the locating pin.

[0035] Generally, any lifting device capable of meeting the load-bearing requirements can be selected for hoisting. However, considering the adaptability to different vessels, the hoisting tool in this embodiment is achieved by welding several lifting rings onto the hull. Specifically, four lifting rings are welded to the hull above the duct. Due to the different vessel types, the specific welding positions of the lifting rings need to be arranged according to the actual site conditions. The load-bearing capacity of the lifting rings must be greater than 1.5 times the weight of the propeller blades. During construction, to ensure the reliability of the welding, the welded joints of the lifting rings should be inspected for defects such as cracks using dye penetrant testing.

[0036] Step 2: Loosen the bolts at the rotor hub flange and rotate the blade to be removed to a specific position. Generally, there is a locking mechanism above the bolts at the rotor hub flange. Therefore, when loosening the bolts at the rotor hub flange, you need to first grind away the locking mechanism on the flange bolts. Removing the locking mechanism should only be done in a way that does not affect the subsequent loosening of the rotor hub flange bolts. After removing the locking mechanism, use a dedicated hydraulic wrench to loosen the bolts. Specifically, when loosening the bolts, only loosen the bolt torque; leave the bolts temporarily in place.

[0037] Rotating the blades to a specific position facilitates disassembly. Engineers can choose the direction that allows the blades to generate sufficient self-weight, based on the actual condition of the blades within the duct. In this embodiment, the preferred position is the 6 o'clock position. This is because after loosening the bolts, when the blades to be disassembled are rotated to the 6 o'clock position, they receive maximum downward self-weight, facilitating their detachment from the hub flange and also making it easier for the blades to leave the duct. Specifically, this can be determined by ensuring the hub flange is directly below and facing the ground, indicating that the blades to be disassembled have been rotated to the 6 o'clock position. Figure 2 (At the arrow)

[0038] Step 3: Insert a shim under the blade to be removed to fix the blade in position and prevent it from rotating or flipping. Generally, as long as the shim can be placed between the blade to be removed and the guide tube ( Figure 1The fixed block is used to support the blade before the blade is removed, so the engineer can use the materials on site according to the actual environment, which greatly facilitates the work. In this embodiment, the fixed block is a customized wedge, and the engineer generally customizes the specifications of the wedge according to the size of the blade by the shipyard carpenter.

[0039] After the fixed block is inserted, several lifting belts are wound around the flange of the blade to be removed, and are hung on the lifting ring through the chain hoist. Specifically, in this embodiment, four lifting belts are wound around the flange of the blade to be removed, and four chain hoists are hung on the lifting ring, and then the lifting belts are hung on the chain hoists, respectively. The lifting belts are slowly tightened until the lifting belts are tightened. The lifting belts and the chain hoists are required to bear a weight greater than 1.5 times the weight of the blade.

[0040] Step 4: Remove the wedge and slowly loosen the chain hoist, so that the blade slowly separates from the flange of the hub by gravity. After the blade separates from the flange, the blade is slowly taken out of the duct by the weight of the blade.

[0041] Step 5: The other blades are removed in sequence according to the above steps until all the blades of the propeller are removed.

[0042] When the maintenance is completed, the blades need to be installed in the duct in the reverse order of the above steps. The specific steps are not repeated.

[0043] In particular, before the wedge is removed to remove the blade, the hydraulic oil in the hub should be drained first to ensure that the lubricating oil does not leak to the dock bottom and pollute the environment. The specific operation is to open the plug of the hub and use a special oil pan to empty the lubricating oil in the hub. The hydraulic oil can be drained at any step between step 1 and step 3. The engineer can perform it according to the actual situation, but it is necessary to check whether the hydraulic oil has been drained before the wedge is removed. After the blades are reinstalled, the hydraulic oil should be refilled.

[0044] The method of directly disassembling and assembling the blades in the duct of the present embodiment can completely avoid the existing technology of pulling out the tail shaft, and can be realized without a large amount of manpower and time. The existing technology of pulling out the tail shaft to disassemble a 4-blade propeller requires about 10 persons and about 48 hours; while the present embodiment directly disassembles and assembles the blades in the duct only needs 4 construction personnel and about 6 hours, greatly reducing the cost of manpower and capital investment; at the same time, the equipment is also disassembled, and large lifting equipment is not needed, greatly reducing the safety risk.

[0045] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0046] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the above specific embodiments, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which do not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict, provided that they do not conflict.

Claims

1. A method of dismounting a propeller blade of a controllable pitch propeller in a duct of a marine vessel, characterized in that, The step of removing the blade includes the following steps: Step 1: prepare the hanging tool for hanging the blade; adjust the blade to a certain pitch position, so that there is a distance between the blade and the duct that can make the blade separate from the duct; Step 2: loosen the bolts at the hub flange, and turn the blade to be removed to a certain direction to facilitate the separation of the blade from the hub flange; Step 3: insert a spacer under the blade to be removed to fix the position of the blade and ensure that the blade does not rotate and overturn; wrap several lifting belts around the blade flange, and hang the lifting belts on the hanging tool through a hand-operated hoist; Step 4: remove the spacer, slowly loosen the hand-operated hoist, and let the blade slowly separate from the hub flange by its own weight; Step 5: remove the other blades in sequence according to the above steps until all the blades are removed.

2. The method of claim 1, wherein, In any one of steps 1 to 3, the hydraulic oil in the hub is released.

3. The method of claim 1, wherein, The pitch position is a zero pitch position.

4. The method of claim 1, wherein, The weight of the hanging tool is greater than 1.5 times the weight of the blade.

5. The method of claim 1, wherein, The hanging tool is a number of lifting rings welded on the hull.

6. The method of claim 1, wherein, The lifting belt has a weight greater than 1.5 times the weight of the blade.

7. The method of claim 1, wherein, The spacer is customized according to the size of the blade.

8. The method of claim 1, wherein, The direction in step 2 is the 6 o'clock direction.

9. The method of claim 1, wherein, The weight of the hand-operated hoist is greater than 1.5 times the weight of the blade.

10. The method of claim 1, wherein, The step of installing the blade is as follows: Step 1: wrap several lifting belts around the blade flange to be installed, and hang the lifting belts on the hanging tool through a hand-operated hoist; Step 2: turn the hub flange of the blade to be installed to a certain direction, and slowly tighten the hand-operated hoist to slowly fit the blade to the hub flange; Step 3: insert a spacer under the blade to fix the position of the blade and ensure that the blade does not rotate and overturn; Step 4: tighten the bolts at the hub flange to complete the installation of the blade; Step 5: install the other blades in sequence according to the above steps until all the blades are installed.

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