CN100423886C - Large ship stern tube bearing cold installation method and refrigeration device - Google Patents

Abstract

The invention relates to a method for cold-installing a stern tube bearing of a large ship and a refrigerating device. The refrigerating device includes a cylinder body made of a material with high strength and low heat transfer coefficient. End covers are provided at both ends of the cylinder body, which can be flexibly connected with the cylinder body. For loading and unloading, a liquid nitrogen spray pipe is installed in the cylinder, and guide rails are laid on the inner wall below the cylinder. There is a bracket on the outside, and the bracket is equipped with guide rails to connect with the guide rails in the cylinder. The trolley with wheels is installed on the guide rails. The stern tube bearing to be cold-installed is placed on the trolley. Spray liquid nitrogen for refrigeration. After spraying, open the end cover to measure the outer diameter of the stern tube bearing. When the shrinkage size requirement is met, pull out the stern tube bearing and cold install it into the stern tube to complete the assembly of the stern tube bearing and the stern tube. Cold assembly. The advantages are: high assembly efficiency, material saving and cost reduction.

Description

Large ship stern tube bearing cold installation method and refrigeration device

(1) Technical field

The invention relates to the field of shipbuilding, in particular to a method for cold-installing a stern tube bearing of a large ship and a refrigeration device.

(2) Background technology

The stern tube bearing and the stern tube have an interference fit. In the past assembly method, the stern tube bearing is processed according to the measured stern shaft hole inner diameter after the ship’s stern tube is bored and the interference amount of the stern tube bearing press-in. Tube bearing outer diameter dimensions. Traditionally, stern tube bearings are press-fitted using a dry hydraulic installation method. This method is adopted by most shipyards in China. According to the traditional method, the installation quality of the stern tube bearing will be affected by the ambient temperature, the technical level of the installer, the shape and position tolerance of the stern tube inner hole, the surface roughness of the stern tube inner hole, and the stern tube bearing. Influenced by many other factors. This method is time-consuming and labor-intensive, and the surface of the stern tube bearing is often worn and the interference is reduced; or the bearing deviates from the axis, and sometimes even the matching surface between the stern tube bearing and the stern tube is burned or seized, causing the stern tube Problems such as bearing scrapping.

(3) Contents of the invention

The technical problem to be solved by the present invention is to provide a large-scale ship bearing cold assembly method and refrigeration device that can improve assembly efficiency, save materials and reduce costs without repairing and straining the assembly surface at one time.

The technical solutions adopted are:

Large ship stern tube bearing refrigeration device, including cylinder, spray pipe, trolley, guide rail, bracket, end cover. The cylinder body is made of fiberglass material with high strength and small heat transfer coefficient, and the outer surface is insulated. There are end caps at both ends of the cylinder, and the end caps are connected to the cylinder through the fixing bolts under the end cap and the fixing bolts on the end cap. There is a spray pipe in the cylinder, and the top of the spray pipe is connected to the filling port. There are spray holes, the filling port and the liquid discharge port are fixedly connected to the top and bottom of the cylinder respectively. The guide rail is divided into two parts, which are laid on the inner wall and the bracket under the cylinder. The trolley is mounted on the guide rail through its own wheels, and the cylinder There is a liquid collecting tank on the lower inner wall, the liquid collecting tank is connected to the liquid discharge port, and the bracket is arranged outside the cylinder to transitionally connect the cylinder and the stern tube to form a refrigeration device for cold installation of the stern tube bearing.

The method for cold assembling the stern tube bearing of a large ship includes the following steps:

1. Before cold assembly, measure the temperature of the outer surface of the stern tube bearing and the outer diameter of the stern tube bearing, and make records;

2. Remove the end cover on one side of the cylinder;

3. Install the bracket between the cylinder and the stern tube, the guide rail is divided into two parts, one part is put into the cylinder, and the other part is installed on the bracket, and the guide rails are aligned;

4. Place the trolley with wheels on the guide rail;

5. Put the stern tube bearing on the trolley, align the large end of the stern tube bearing with the cylinder of the cooling device, and align the small end with the stern tube;

6. Push the stern tube bearing into the barrel through the trolley, remove the bracket, and fix the upper end cover;

7. The charging port on the barrel is connected to liquid nitrogen, and the liquid nitrogen is sprayed to cool the stern tube bearing through the spray pipes evenly distributed with spray holes;

8. Use a thermocouple to measure the surface temperature of the stern tube bearing, and wait for the surface temperature of the stern tube bearing to drop to the set temperature to complete the cooling;

9. Open the end cover and measure the outer diameter of the stern tube bearing after cooling. If the outer diameter reaches the required shrinkage, remove the end cover and reconnect the bracket between the cylinder and the stern tube;

10. Pull the trolley and the stern tube bearing out of the cylinder, adjust the alignment of the stern tube bearing to the stern tube, and push the stern tube bearing into the stern tube coldly.

In the above step 7, the stern tube bearing is cooled by liquid nitrogen spraying, and the liquid nitrogen pressure is 0.2-0.4Mpa; spraying time: calculate the amount of spraying liquid nitrogen according to the amount of cold shrinkage, and use the set spraying speed to calculate the spraying time. time.

The set temperature in the above step 8 is the final temperature obtained by the sum of the cold shrinkage temperature difference calculated according to the cold shrinkage amount and the surface temperature before cold fitting.

The advantages of the present invention: it can effectively avoid the problem of burning or seizure of the mating surface existing in the traditional dry press-fitting method, shorten the assembly time, simplify the secondary processing procedure after assembly, and change the multi-level repair into a standard-level assembly , to standardize the supply of accessories, greatly improving assembly efficiency, while saving materials and reducing costs.

(4) Description of drawings

Fig. 1 is a schematic diagram of a stern tube bearing refrigeration device of the present invention.

Fig. 2 is a schematic diagram of the installation of the stern tube bearing of the present invention into the refrigeration device.

(5) Specific implementation methods

Example

The refrigerating device for the stern tube bearing of a large ship includes a cylinder body 1, a spray pipe 2, a trolley 3, a guide rail 4, a bracket 11, and an end cover 10. The outer surface of the cylinder body 1 adopts heat insulation measures, and is made of glass fiber reinforced plastic material with high strength and small heat transfer coefficient. The two ends of the cylinder body 1 are provided with end caps 10, and the end caps 10 are fixed by the fixing bolts 7 under the end cap and the top of the end cap. The bolt 8 and the barrel 1 can be flexibly installed and disassembled. The barrel 1 is provided with a spray pipe 2, and the top of the spray pipe 2 is connected to the filling port 5. There are spray holes evenly distributed on the spray pipe, and the filling port 5 and The liquid discharge port 6 is fixedly connected with the top and bottom of the cylinder body 1 respectively, the guide rail 4 is laid on the inner wall below the cylinder body 1, the trolley 3 is mounted on the guide rail 4 through its own wheels, and the inner wall of the cylinder body 1 is provided with a liquid collection tank 9 to collect The liquid tank 9 is connected to the liquid discharge port 6, and the bracket 11 is arranged outside the cylinder body 1 to serve as a transitional connection between the cylinder body 1 and the stern tube 13, constituting a cooling device for the cold installation of the stern tube bearing.

The method for cold assembling the stern tube bearing of a large ship includes the following steps:

1. Before cold assembly, measure the temperature of the outer surface of the stern tube bearing 12 and the outer diameter of the stern tube bearing 12, and make records;

2. Remove the end cover 10 on one side of the cylinder body 1;

3. Install the bracket 11 between the cylinder body 1 and the stern tube 13, the guide rail 4 is divided into two parts, one part is put into the cylinder body 1, and the other part is installed on the bracket 11, and the guide rails are aligned;

4. Place the trolley 3 with wheels on the guide rail 4;

5. Put the stern tube bearing 12 on the trolley 3, align the large end of the stern tube bearing 12 with the cylinder 1 of the cooling device, and align the small end with the stern tube 13;

6. Push the stern tube bearing 12 into the barrel 1 through the trolley 3, remove the bracket 11, and fix the upper end cover 10;

7. The filling port 5 on the barrel 1 is connected to liquid nitrogen, and the liquid nitrogen is sprayed to cool the stern tube bearing 12 through the spray pipe 2 with evenly distributed spray holes. The pressure of the liquid nitrogen is 0.3Mpa, and the spray time is calculated 25 minutes out;

8. Use a thermocouple to measure the surface temperature of the stern tube bearing 12. After the surface temperature of the stern tube bearing 12 drops to the calculated minus 90°C, the cooling ends;

9. Open the end cover 10, measure the outer diameter of the stern tube bearing 12 after cooling, the outer diameter reaches the required cold shrinkage, remove the end cover 10, and reconnect the bracket 11 between the cylinder body 1 and the stern tube 13;

10. Pull the trolley 3 and the stern tube bearing 12 out of the cylinder body 1, adjust the alignment of the stern tube bearing 12 to the stern tube 13, and push the stern tube bearing 12 into the stern tube 13 coldly.

Claims (4)

1. large ship stern tube bearing refrigerating plant comprises cylindrical shell (1), shower (2), dolly (3), guide rail (4), support (11), end cap (10); The glass-reinforced plastic material that cylindrical shell (1) is big with intensity, heat transfer coefficient is very little is made, and outer surface is taked adiabatic measure; Cylindrical shell (1) two ends are provided with end cap (10), and end cap (10) is connected with cylindrical shell (1) by gim peg (8) on gim peg under the end cap (7) and the end cap; Be provided with shower (2) in the cylindrical shell (1), shower (2) top connects filled mouthful (5), is evenly equipped with spray apertures on the shower, fills mouthful (5) and fixedlys connected with cylindrical shell (1) above and below respectively with tap hole (6); Guide rail (4) is laid on the inwall of cylindrical shell (1) below and on the support (11) for two parts, and dolly (3) is contained on the guide rail (4) by self wheel; Cylindrical shell (1) below inwall is provided with collecting tank (9), and collecting tank (9) is connected with tap hole (6); Support (11) is located at cylindrical shell (1) outside, is positioned between cylindrical shell (1) and the stern tube shaft pipe (13).

2. large ship stern tube bearing cold fitting method, its feature comprises the following steps:

Before A, the cold charge, measure stern tube bearing (12) hull-skin temperature and stern tube bearing (12) outside dimension, and note down;

B, cylindrical shell (1) one side end cap (10) is removed;

C, between cylindrical shell (1) and stern tube shaft pipe (13) mounting bracket (11), guide rail (4) separated into two parts, the part cylindrical shell (1) of packing into, another part is contained on the support (11), guide rail (4) alignment;

D, go up to place belt wheel dolly (3) at guide rail (4);

E, stern tube bearing (12) is placed on the dolly (3), the big end of stern tube bearing (12) is aimed at the cylindrical shell (1) of cooling device, and small end is aimed at stern tube shaft pipe (13);

F, stern tube bearing (12) is pushed in the cylindrical shell (1) by dolly (3), remove support (11), fixedly upper end cover (10);

Filled mouthful (5) on G, the cylindrical shell (1) connect liquid nitrogen, shower (2) the spray cooling stern tube bearing (12) of liquid nitrogen through being evenly equipped with spray apertures;

H, with thermocouple measurement stern tube bearing (12) surface temperature, treat that stern tube bearing (12) surface temperature reduces to the design temperature cooling and finish;

I, open end cap (10), measure cooling back stern tube bearing (12) external diameter, its outside dimension meets the requirements of the shrinkage amount, removes end cap (10), connects support (11) again between cylindrical shell (1) and stern tube shaft pipe (13);

J, dolly (3) and stern tube bearing (12) are pulled out cylindrical shell (1), adjust stern tube bearing (12) centering stern tube shaft pipe (13), promote stern tube bearing (12) cold charge and go into stern tube shaft pipe (13).

3. large ship stern tube bearing cold fitting method according to claim 2 is characterized in that described step (G) liquid nitrogen spraying cooling stern tube bearing, and its liquid nitrogen pressure is 0.2-0.4Mpa; Spray time: calculate the spray amount of liquid nitrogen according to the shrinkage amount, utilize and set spray rate, and then calculate spray time.

4. large ship stern tube bearing cold fitting method according to claim 2, it is characterized in that described step (H) stern tube bearing (12) surface temperature reduces to design temperature, the shrinkage temperature difference and the cold charge front surface temperature sum of design temperature for calculating according to the shrinkage amount, the temperature that finally obtains.

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