1. The mounting and dismounting process of the lower guide bearing fixing ring of the main shaft seal pump of the nuclear power station is characterized by comprising the following steps of: by fixing device (1), hexagon socket head cap screw pretension instrument (2), the fixed lantern ring (3), one set of mounting tool is constituteed in installation pipe (4), specialized tool is vertical structure, adopt fixing device (1) to lead solid fixed ring of bearing (5) and installation pipe (4) to assemble together down at the pump body, adopt the crane with mounting tool and lead solid fixed ring of bearing (5) down pack into in the pump body, adopt fixed lantern ring (3) fixed hexagon socket head cap screw pretension instrument (2), torque wrench passes through fixed hexagon socket head cap screw pretension instrument (2) transmission moment of torsion and gives waist bolt (7), thereby reach the locking moment of torsion of waist bolt (7) installation, this set of mounting tool has guaranteed the accurate positioning and the installation of the solid fixed ring of lower guide bearing (5), above-mentioned method includes following steps:

1) firstly, a mounting tube (4) is placed on a lower guide bearing fixing ring (5) outside a pump body, the top of the mounting tube (4) is installed into a fixing device (1), a lower bolt of the fixing device (1) is screwed into the lower guide bearing fixing ring (5), and thus the lower guide bearing fixing ring (5) is fixed to the lower part of the mounting tube (4) in a threaded connection mode;

2) after the fixed lantern ring (3) is arranged in the inner hexagon bolt pre-tightening tool (2), the inner hexagon bolt pre-tightening tool (2) is arranged in the installation pipe (4);

3) hoisting the fixing device (1), the inner hexagon bolt pre-tightening tool (2), the fixed lantern ring (3), the mounting pipe (4) and the lower guide bearing fixing ring (5) together by using a crane, adjusting the levelness of the mounting pipe (4) to 0.02mm/m, and slowly placing the lower guide bearing fixing ring (5) into the pump body; the coaxiality of the upper spigot and the lower spigot of the mounting pipe (4) is 0.02mm, the sizes of the upper spigot and the lower spigot are actually matched according to the sizes of the spigot of the lower guide bearing fixing ring (5) and the sealing chamber (8), and the matching gap is ensured to be 0.02mm, so that the mounting coaxiality of the lower guide bearing fixing ring (5) and the sealing chamber (8) is ensured, and the problems of clamping stagnation and grinding damage caused by small mounting gap of the lower guide bearing fixing ring (5) are prevented;

4) the torque wrench is placed at the top of the inner hexagon bolt pre-tightening tool (2), the inner hexagon bolt pre-tightening tool (2) is rotated, the lower part of the inner hexagon bolt pre-tightening tool (2) is connected with the waist bolt (7) in an inner hexagon mode, the inner hexagon bolt pre-tightening tool (2) is used for transmitting torque, the waist bolt (7) is used for fixing the lower guide bearing fixing ring (5) and the guide vane (6), and the locking torque value is 201.0 Nm;

5) and (3) loosening the fixing device (1), hoisting the fixing device (1), the hexagon socket head cap screw pre-tightening tool (2), the fixing sleeve ring (3) and the mounting pipe (4) by using a crane, moving out of the main pump, and finishing mounting.

2. The process for installing and disassembling the lower guide bearing fixing ring of the main shaft seal pump in the nuclear power station as claimed in claim 1, wherein: the installation of bearing seal formula main pump lower guide bearing fixed ring is the installation in the cavity, and the space is narrow and small, and the installation degree of depth size has reached 1734 mm.

Background art:

the shaft-sealed nuclear main pump is one of the most critical nuclear island main devices in a loop system of a nuclear power station, and represents the highest level of design and manufacture of the current pump products, wherein the lower guide bearing is a key part of a shaft seal pump, the lower guide bearing fixing ring is used for fixing the lower guide bearing of the nuclear main pump, the installation precision of the lower guide bearing fixing ring directly influences the operation vibration value of the whole nuclear main pump, at present, various installation and disassembly modes are available at home and abroad, but in actual operation, a special tool is lacked, the whole installation process is complex, not only the time consumption is long, but also the accurate installation is difficult, the phenomena of clamping stagnation, part collision and grinding damage are easy to occur in the assembly process, and the lower guide bearing fixing ring is required to be installed at the lowest end of the whole main pump body, the installation depth is large.

The invention content is as follows:

the invention aims to provide a process for mounting and dismounting a lower guide bearing fixing ring of a main shaft seal pump of a nuclear power station, which solves the difficulty that a torque wrench cannot fasten bolts due to large mounting depth and prevents the problems of clamping stagnation and grinding damage caused by small mounting clearance of the lower guide bearing fixing ring (5).

The technical scheme of the invention is as follows: a process for installing and detaching a lower guide bearing fixing ring of a main shaft seal pump of a nuclear power station comprises a fixing device (1), an inner hexagon bolt pre-tightening tool (2), a fixing lantern ring (3) and an installing pipe (4) to form a set of installing tool, wherein the special tool is of a vertical structure, the lower guide bearing fixing ring (5) and the mounting pipe (4) are assembled together by adopting a fixing device (1) outside the pump body, a mounting tool and the lower guide bearing fixing ring (5) are arranged in the pump body by adopting a crane, an inner hexagon bolt pre-tightening tool (2) is fixed by adopting a fixing lantern ring (3), a torque wrench transmits torque to the waist-contracting bolt (7) through the fixed inner hexagon bolt pre-tightening tool (2), so that the locking torque for mounting the waist-contracting bolt (7) is achieved, the mounting tool ensures the accurate positioning and mounting of the lower guide bearing fixing ring (5), and the method comprises the following steps:

1) firstly, a mounting tube (4) is placed on a lower guide bearing fixing ring (5) outside a pump body, the top of the mounting tube (4) is installed into a fixing device (1), a lower bolt of the fixing device (1) is screwed into the lower guide bearing fixing ring (5), and thus the lower guide bearing fixing ring (5) is fixed to the lower part of the mounting tube (4) in a threaded connection mode;

2) after the fixed lantern ring (3) is arranged in the inner hexagon bolt pre-tightening tool (2), the inner hexagon bolt pre-tightening tool (2) is arranged in the installation pipe (4);

3) hoisting the fixing device (1), the inner hexagon bolt pre-tightening tool (2), the fixed lantern ring (3), the mounting pipe (4) and the lower guide bearing fixing ring (5) together by using a crane, adjusting the levelness of the mounting pipe (4) to 0.02mm/m, and slowly placing the lower guide bearing fixing ring (5) into the pump body;

4) the torque wrench is placed at the top of the inner hexagon bolt pre-tightening tool (2), the inner hexagon bolt pre-tightening tool (2) is rotated, the lower part of the inner hexagon bolt pre-tightening tool (2) is connected with the waist bolt (7) in an inner hexagon mode, the inner hexagon bolt pre-tightening tool (2) is used for transmitting torque, the waist bolt (7) is used for fixing the lower guide bearing fixing ring (5) and the guide vane (6), and the locking torque value is 201.0 Nm;

5) loosening the fixing device (1), hoisting the fixing device (1), the inner hexagon bolt pre-tightening tool (2), the fixing sleeve ring (3) and the mounting pipe (4) by using a crane, moving out of the main pump, and finishing mounting;

the installation of bearing seal formula main pump lower guide bearing fixed ring is the installation in the cavity, and the space is narrow and small, and the installation degree of depth size has reached 1734 mm.

The invention has the technical effects that:

1) the fixing ring of the lower guide bearing of the shaft seal type main pump is installed in a cavity, the installation space is narrow, the installation depth size reaches 1734mm, the installation is very difficult, the installation gap is only 0.02mm, and the collision is easy to occur.

2) According to the invention, the torque of the torque wrench is transmitted to the waisted bolt (7) through the inner hexagon bolt pre-tightening tool (2), so that the torque value of the waisted bolt (7) reaches a safe locking torque value, whether the waisted bolt (7) is firmly installed or not is eliminated by only relying on the experience of an operator, and the difficulty that the torque wrench cannot tighten the bolt due to large installation depth is solved;

3) according to the invention, the fixing device (1) is adopted to fix the lower guide bearing fixing ring (5) on the mounting pipe (4), so that the problems of fixing of parts with large mounting depth and large size and difficulty in dismounting the fixing tool after mounting are solved, and the tool is simple to operate;

4) the coaxiality of the upper spigot and the lower spigot of the tool mounting tube (4) is 0.02mm, the sizes of the upper spigot and the lower spigot are actually matched according to the sizes of the spigot of the lower guide bearing fixing ring (5) and the sealing chamber (8), and the matching gap is ensured to be 0.02mm, so that the mounting coaxiality of the lower guide bearing fixing ring (5) and the sealing chamber (8) is ensured, and the problems of clamping stagnation and grinding damage caused by the small mounting gap of the lower guide bearing fixing ring (5) are prevented.

5) The tool can also be used for disassembling the lower guide bearing fixing ring during the maintenance of the nuclear power station.

Description of the drawings:

FIG. 1 is a schematic view of the mounting of a lower guide bearing retainer ring

The specific implementation mode is as follows:

as shown in fig. 1, a process for installing and disassembling a lower guide bearing fixing ring of a main pump of a shaft seal of a nuclear power station, which comprises a fixing device 1, an inner hexagon bolt pre-tightening tool 2, a fixing sleeve ring 3 and a mounting tube 4, wherein the special tool is of a vertical structure, the fixing device 1 is adopted outside a pump body to assemble the lower guide bearing fixing ring 5 and the mounting tube 4 together, the mounting tool and the lower guide bearing fixing ring 5 are installed in the pump body by a crane, the inner hexagon bolt pre-tightening tool 2 is fixed by the fixing sleeve ring 3, a torque wrench transmits torque to a waisted bolt 7 through the fixing inner hexagon bolt pre-tightening tool 2, so that locking torque for installing the waisted bolt 7 is achieved, the set of mounting tool ensures accurate positioning and installation of the lower guide bearing fixing ring 5, and the method comprises the following steps:

1) firstly, the mounting tube 4 is placed on the lower guide bearing fixing ring 5 outside the pump body, the top of the mounting tube 4 is installed into the fixing device 1, the lower bolt of the fixing device 1 is screwed into the lower guide bearing fixing ring 5, and thus the lower guide bearing fixing ring 5 is fixed to the lower part of the mounting tube 4 in a threaded connection mode;

2) after the fixed lantern ring 3 is arranged in the hexagon socket head cap screw pre-tightening tool 2, the hexagon socket head cap screw pre-tightening tool 2 is arranged in the installation pipe 4;

3) hoisting the fixing device 1, the hexagon socket head cap screw pre-tightening tool 2, the fixed lantern ring 3, the mounting tube 4 and the lower guide bearing fixing ring 5 together by using a crane, adjusting the levelness of the mounting tube 4 to 0.02mm/m, and slowly placing the lower guide bearing fixing ring 5 into the pump body; the coaxiality of the upper spigot and the lower spigot of the mounting tube 4 is 0.02mm, the sizes of the upper spigot and the lower spigot are actually matched according to the sizes of the spigots of the lower guide bearing fixing ring 5 and the sealing chamber 8, and the matching gap is ensured to be 0.02mm, so that the mounting coaxiality of the lower guide bearing fixing ring 5 and the sealing chamber 8 is ensured, and the problems of clamping stagnation and grinding damage caused by the small mounting gap of the lower guide bearing fixing ring 5 are prevented;

4) placing a torque wrench at the top of the inner hexagon bolt pre-tightening tool 2, rotating the inner hexagon bolt pre-tightening tool 2, enabling the lower part of the inner hexagon bolt pre-tightening tool 2 to be in an inner hexagon connection mode with the waisted bolt 7, transmitting torque through the inner hexagon bolt pre-tightening tool 2, enabling the waisted bolt 7 to fix the lower guide bearing fixing ring 5 and the guide vane 6, and enabling a locking torque value to be 201.0 Nm;

5) and (3) loosening the fixing device 1, hoisting the fixing device 1, the hexagon socket head cap screw pre-tightening tool 2, the fixing sleeve ring 3 and the mounting pipe 4 by using a crane, moving out of the main pump, and finishing mounting.

The installation of bearing seal formula main pump lower guide bearing fixed ring is the installation in the cavity, and the space is narrow and small, and the installation degree of depth size has reached 1734 mm.