Protective device and method for root bolt of adjustable pitch blade

Abstract

The present invention relates to a protective device and method for the root bolt of a pitch-adjustable blade. A blade root bolt protective agent is filled in the annular space formed between the head of the blade root bolt and the mounting hole of the blade flange, which is used to ensure the external linear shape of the blade, prevent external foreign matter from entering the annular space area, and form a protective layer outside the blade root bolt. The present invention uses a blade root bolt protective agent to fill the annular space formed by the blade root bolt and the mounting hole of the blade flange, which ensures the external linear shape of the blade, prevents external foreign matter from entering the area, and forms a protective layer outside the blade root bolt. The protective layer has good insulation and corrosion resistance, and can effectively reduce the risk of chemical corrosion, electrochemical corrosion and hydrogen embrittlement fracture of the blade root bolt to a certain extent. At the same time, while isolating the head cone of the blade root bolt from contact with seawater, it can be removed by manual knocking, which is convenient for repeated disassembly and assembly of the blade root bolt.

Description

Technical Field

[0001] The invention relates to a ship adjustable pitch propeller device, in particular to an adjustable pitch propeller blade root bolt in the ship adjustable pitch propeller device. Background Art

[0002] The blade root bolt is one of the important parts of the adjustable pitch propeller device. It is used to connect the blade to the crank plate of the hub. It needs to ensure long-term reliable operation under complex underwater loads. Therefore, it is very important to take necessary protective measures for the blade root bolt. The blade root bolt is located in the blade flange mounting hole. During installation, after tightening the individual blade root bolts one by one and taking anti-loosening measures, the currently commonly used method is to fill the annular space formed by the blade root bolt and the blade flange mounting hole with quick-drying cement or epoxy resin to keep the outer line of the blade smooth, improve the hydrodynamic flow field at the stern of the hull, and prevent the blade root bolt and its anti-loosening pin from being entangled or damaged by underwater foreign objects such as fishing nets. However, the use of quick-drying cement to coat the blade root bolts cannot prevent the contact between the head of the blade root bolt and seawater, and the quick-drying cement is easy to fall off. The blade root bolts are in the marine environment for a long time, and there is a risk of chemical corrosion, electrochemical corrosion and hydrogen embrittlement fracture; while the use of epoxy resin to coat the blade root bolts can prevent the head of the blade root bolts from contacting with seawater, further reducing the risk of chemical corrosion, electrochemical corrosion and hydrogen embrittlement fracture of the bolts, but the adhesion of epoxy resin is strong, and it is difficult to remove it once filled. When the ship enters the dock again to check the blade seal ring and remove the blade root bolts, the epoxy resin inside the pit cannot be removed, which will affect the normal removal of the blade root bolts. It is a major problem currently faced to isolate the head of the blade root bolt from contact with seawater and facilitate the repeated disassembly and assembly of the blade root bolts. Therefore, a protection method for the root bolts of adjustable pitch propellers is needed to solve the above difficulties. Summary of the invention

[0003] The present invention aims to provide a novel protective device and method for the root bolt of an adjustable pitch propeller blade. A protective agent is filled at the root bolt, i.e., the recess of the blade flange, which can prevent the round cone of the head of the root bolt from contacting the seawater and can be removed by manual knocking, thereby facilitating repeated disassembly and assembly of the root bolt, and can be applied to the adjustable pitch propeller device of a ship power propulsion system.

[0004] To achieve the above-mentioned purpose, the technical solution of the present invention is: a protective device for the root bolt of a pitch-adjustable blade, comprising a blade flange and a blade root bolt, the blade is connected to the crank plate through the blade flange, and the blade flange and the crank plate are fixedly connected by multiple blade root bolts, wherein the annular space formed between the head of the blade root bolt and the mounting hole of the blade flange is filled with a blade root bolt protective agent, which is used to ensure the external linear shape of the blade, prevent external foreign matter from entering the annular space area, and form a protective layer on the outside of the blade root bolt.

[0005] A method for implementing a protective device for a pitch-adjustable blade root bolt, the steps of which are:

[0006] Step 1: Prepare the blade root bolt protective agent: Mix epoxy resin, curing agent and wood shavings in a volume ratio of about 1:1:1 to form the blade root bolt protective agent. After the preparation, it will gradually solidify within 24 hours in the natural environment and needs to be prepared before use.

[0007] Step 2: Fill the annular space formed by the blade root bolt and the installation hole of the blade flange with blade root bolt protection; after the filling is completed, wait for the blade root bolt protective agent to solidify to form a protective layer; the solidification process is natural solidification in the air, and no human intervention is required;

[0008] Step three, remove the protective layer by manual knocking, and knock the protective layer with a hammer and a chisel to separate and fall off the protective layer in the form of flakes or particles.

[0009] The beneficial effects of the present invention are:

[0010] The present invention uses a blade root bolt protective agent to fill the annular space formed by the blade root bolt and the blade flange mounting hole, thereby ensuring the external linear shape of the blade, preventing external foreign matter from entering the area, and forming a protective layer outside the blade root bolt. The protective layer has good insulation and corrosion resistance, and can effectively reduce the risk of chemical corrosion, electrochemical corrosion and hydrogen embrittlement fracture of the blade root bolt to a certain extent. At the same time, while isolating the head cone of the blade root bolt from contact with seawater, it can be removed by manual knocking, which is convenient for repeated disassembly and assembly of the blade root bolt. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic structural diagram of a protective device for a pitch-adjustable blade root bolt of the present invention;

[0012] Figure 2 It is a cross-sectional view of the protective device structure of the pitch-adjustable blade root bolt of the present invention;

[0013] Figure 3 It is a partial schematic diagram of the filling position of the present invention;

[0014] In the figure, 1. blade root bolt protective agent, 2. blade root bolt, 3. blade, 4. crank plate, blade flange 5. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0016] like Figures 1 to 3As shown, a protective device for the root bolt of a pitch-adjustable blade includes a blade flange 5 and a blade root bolt 2. The blade 3 is connected to the crank plate 4 through the blade flange 5. The blade flange 5 and the crank plate 4 are fixedly connected by a plurality of blade root bolts 2. The annular space formed between the head of the blade root bolt 2 and the mounting hole of the blade flange 5 is filled with a composite coating containing epoxy resin, i.e., a blade root bolt protective agent 1. When the blade root bolt needs to be disassembled, it is removed by manual knocking.

[0017] A method for protecting a pitch-adjustable blade root bolt, comprising the following steps:

[0018] Step 1: Prepare the blade root bolt protective agent 1

[0019] Epoxy resin, curing agent and wood shavings are mixed in a volume ratio of about 1:1:1 to form blade root bolt protective agent 1. After being mixed, it gradually solidifies within 24 hours under natural conditions and needs to be prepared before use.

[0020] Step 2: Fill the annular space formed by the blade root bolt 2 and the mounting hole of the blade flange 5 with the blade root bolt protective agent 1;

[0021] After the filling is completed, wait for the blade root bolt protective agent 1 to solidify to form a protective layer; the solidification process is natural solidification in the air, and no human intervention is required;

[0022] Step three, remove the protective layer by manual knocking, and knock the protective layer with a hammer and a chisel to separate and fall off the protective layer in the form of flakes or particles.

Claims

1. A method for implementing a protective device for a pitch-adjustable blade root bolt, the protective device for the pitch-adjustable blade root bolt comprises a blade flange and a blade root bolt, the blade is connected to a crank plate via the blade flange, the blade flange and the crank plate are fixedly connected by a plurality of blade root bolts, wherein: The annular space formed between the blade root bolt head and the mounting hole of the blade flange is filled with a blade root bolt protective agent to ensure the outer linear shape of the blade, prevent external foreign matter from entering the annular space area, and form a protective layer outside the blade root bolt, characterized in that: the steps of the implementation method are: Step 1: Prepare the blade root bolt protective agent: Mix epoxy resin, curing agent and wood shavings in a volume ratio of about 1:1:1 to form the blade root bolt protective agent. After the preparation, it will gradually solidify within 24 hours in the natural environment and needs to be prepared before use. Step 2: Fill the annular space formed by the blade root bolt and the installation hole of the blade flange with blade root bolt protection; after the filling is completed, wait for the blade root bolt protective agent to solidify to form a protective layer; the solidification process is natural solidification in the air, and no human intervention is required; Step three, remove the protective layer by manual knocking, and knock the protective layer with a hammer and a chisel to separate and fall off the protective layer in the form of flakes or particles.

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