A device and method for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant

Abstract

The present invention belongs to the field of maintenance engineering for rotating equipment in nuclear power plants, and specifically discloses a device and method for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant. The device includes a sleeve, an upper bearing end cover, an upper bearing chamber, a lower bearing chamber, a ratchet wrench, a lower bearing end cover, a main gear shaft, and a driven gear shaft. The method is as follows: Step 1, install the pump shaft of the seawater circulation pump in the nuclear power plant into the sleeve of the pump shaft lifting and lowering device; Step 2, rotate the main gear shaft of the pump shaft lifting and lowering device to drive the driven gear shaft to rotate; Step 3, the driven gear shaft rotates to drive the sleeve to rotate, thereby lifting the pump shaft of the seawater circulation pump upward. The invention has a simple structure and is convenient to use, can lift and lower the pump shaft in a very short time, effectively avoids potential risks threatening the safety of personnel and equipment during the process of lifting and lowering the pump shaft, and can also meet different models of super bolts.

Description

Technical Field

[0001] The invention belongs to the field of maintenance engineering of rotating equipment in nuclear power plants, and particularly relates to a device and method for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant. Background Art

[0002] As is well known, during the disassembly and assembly of large vertical pumps, most of them will face the process of lifting and lowering the pump shaft, and the relatively heavy pump shaft is extremely risky during the lifting and lowering process. During the maintenance of the vertical seawater circulation pump, the pump shaft and the impeller need to be lowered together onto the lower orifice ring of the impeller, and the impeller needs to be lifted again during reinstallation. The pump shaft and the impeller weigh about 2T. During the process of lifting and lowering the shaft, super bolts need to be inserted into the super bolt holes of the coupling, a striking wrench needs to be clamped onto the nut, and a sledgehammer is used to strike the wrench to loosen the nut so that the pump shaft can slowly rise or fall. However, the space inside the pump cavity is narrow. Using a sledgehammer to strike not only causes damage to the equipment, but also causes injuries to maintenance personnel. The whole process is time-consuming and laborious, and extremely risky.

[0003] How to reliably lift and lower the pump shaft of the seawater circulation pump is of great significance for the safety of personnel and equipment during the maintenance process. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: The present invention provides a device and method for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant, which has a simple structure and is easy to use. It can lift and lower the pump shaft in a very short time, effectively avoiding potential risks that threaten the safety of personnel and equipment during the process of lifting and lowering the pump shaft, and can also meet different models of super bolts.

[0005] The technical solution for achieving the purpose of the present invention: A device for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant, characterized in that: the device includes a sleeve, an upper bearing end cover, an upper bearing chamber, a lower bearing chamber, a ratchet wrench, a lower bearing end cover, a main gear shaft and a driven gear shaft. An upper bearing end cover is provided at the top of the upper bearing chamber, and several sleeves communicating with its interior are provided along the circumference in the middle of the upper bearing chamber; the bottom of the upper bearing chamber is connected to the top of the lower bearing chamber, and the two form a cavity; a lower bearing end cover is provided at the bottom of the lower bearing chamber; the main gear shaft and several driven gear shafts are located in the cavity formed by the upper bearing chamber and the lower bearing chamber, and several driven gear shafts are evenly arranged along the circumference of the main gear shaft. The main gear of the main gear shaft meshes with the secondary gear of the driven gear shaft; through holes are opened in the centers of both the upper bearing end cover and the lower bearing end cover, and the top and bottom of the main gear shaft are respectively installed in the through holes in the centers of the upper bearing end cover and the lower bearing end cover; the end of the bottom of the main gear shaft is fixedly connected to the ratchet wrench; the bottom of the driven gear shaft is located inside the inner wall of the lower bearing chamber, and the top of the driven gear shaft is located inside the sleeve.

[0006] Deep groove ball bearings are provided between the top of the main gear shaft and the inner wall of the upper bearing end cover, and between the bottom of the main gear shaft and the inner wall of the lower bearing end cover.

[0007] A lip seal is provided between the top of the main gear shaft and the inner wall of the upper bearing end cover, and between the bottom of the main gear shaft and the inner wall of the lower bearing end cover.

[0008] A self-lubricating bearing is provided between the bottom of the driven gear shaft and the lower bearing chamber.

[0009] Circlips are sleeved outside both the top and bottom of the main gear shaft, and the circlips are located between the lip seal and the deep groove ball bearing.

[0010] A dial is provided on the outer surface of the bottom of the lower bearing end cover, and the dial is sleeved outside the main gear shaft.

[0011] The pointer of the dial is fixed at a position corresponding to the dial on the main gear shaft.

[0012] The bottom of the main gear shaft is fixedly connected to a ratchet wrench through a ratchet sleeve.

[0013] The bottom flange of the upper bearing chamber is connected to the top flange of the lower bearing chamber.

[0014] A method for lifting and lowering the pump shaft of a nuclear power plant seawater circulation pump, the specific steps of the method are as follows:

[0015] Step 1: Install the pump shaft of the nuclear power plant seawater circulation pump into the sleeve of the pump shaft lifting and lowering device;

[0016] Step 2: Rotate the main gear shaft of the pump shaft lifting and lowering device to drive the driven gear shaft to rotate;

[0017] Step 3: The driven gear shaft rotates to drive the sleeve to rotate, thereby lifting the pump shaft of the seawater circulation pump upward.

[0018] In step 1, a super bolt is installed on the pump shaft of the seawater circulation pump, and a super nut for installing the super bolt is installed. The sleeve of the pump shaft lifting and lowering device is sleeved outside the super nut.

[0019] In step 2, the ratchet wrench drives the main gear shaft to rotate, and the main gear shaft transmits the force to the driven gear shaft to drive the driven gear shaft to rotate.

[0020] When the main gear shaft rotates in step 3, the pointer on the main gear shaft can display the rotation degree on the dial; according to the rotation degree, the pump shaft of the seawater circulation pump is rotated by the same angle in each direction at the same time, ensuring that the pump shaft rises by the same height each time, and realizing the lifting of the pump shaft of the seawater circulation pump.

[0021] The beneficial technical effects of the present invention are as follows: (1) The pump shaft lifting device of the seawater circulation pump of the present invention can cooperate with the super bolt to lift the shaft. As long as a ratchet wrench is used to apply force to the main shaft, it is simple, reliable, and efficient, and it can also avoid damage to the equipment and personnel. A dial is installed on the lifting device, which can ensure that each bolt rotates the same angle, enabling the pump shaft to rise smoothly and effectively avoiding being pulled askew. The lifting tool can adjust the size of the socket head according to the bolt size, meeting the requirements of more equipment. (2) The device of the present invention fixes the intermediate main gear shaft on the upper and lower bearing chambers through two deep groove ball bearings up and down, which can ensure the smooth rotation of the intermediate shaft. Below the intermediate shaft is connected to the ratchet wrench, and during the shaft lifting process, only a ratchet wrench needs to be used to apply force. (3) The intermediate main gear of the present invention meshes with three other sub-gears. The three driven gear shafts are fixed in three directions of the bearing chamber through self-lubricating bearings and are arranged at 120° respectively with the main gear. The upper parts of the three sub-gears are made in a style that can be connected to the socket head, facilitating the change of the socket head size to meet the requirements of different-sized bolts. (4) At the bottom of the lower bearing end cover of the present invention, a dial and a pointer are installed. The pointer is fixed together with the main gear shaft. During each working process, the rotation of the intermediate main gear shaft can be judged by observing the position of the pointer on the dial. Rotating the same angle simultaneously in four directions of the seawater circulation pump coupling can ensure that the pump shaft rises by the same height each time, enabling the pump shaft to rise smoothly and effectively avoiding the phenomenon of deviation during the rising process of the pump shaft. Brief Description of the Drawings

[0022] Figure 1 FIG. is a schematic structural diagram of a device for lifting and lowering the pump shaft of a nuclear power plant seawater circulation pump provided by the present invention;

[0023] Figure 2 FIG. is a partial cross-sectional view of a device for lifting and lowering the pump shaft of a nuclear power plant seawater circulation pump provided by the present invention;

[0024] In the figure: 1. Sleeve; 2. Upper bearing end cover; 3. Upper bearing chamber; 4. Connecting bolt; 5. Gasket; 6. Nut; 7. Lower bearing chamber; 8. Dial; 9. Ratchet wrench; 10. Ratchet socket; 11. Lower bearing end cover; 12. Main gear shaft; 13. Lip seal; 14. Snap ring; 15. Deep groove ball bearing; 16. Self-lubricating bearing; 17. Driven gear shaft; 18. Bearing end cover bolt. Detailed Description of the Invention

[0025] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0026] As Figure 1 and Figure 2As shown in the figure, a device for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant provided by the present invention includes a sleeve 1, an upper bearing end cover 2, an upper bearing chamber 3, connecting bolts 4, gaskets 5, nuts 6, a lower bearing chamber 7, a dial 8, a ratchet wrench 9, a ratchet sleeve 10, a lower bearing end cover 11, a main gear shaft 12, a lip seal 13, a circlip 14, a deep groove ball bearing 15, a self-lubricating bearing 16, a driven gear shaft 17, and bearing end cover bolts 18.

[0027] As Figure 1 shown, the top of the upper bearing chamber 3 is fixedly connected to the upper bearing end cover 2 by four bearing end cover bolts 18 evenly arranged in the circumferential direction. A cylindrical through hole communicating with the inside of the upper bearing chamber 3 is opened in the center of the upper bearing end cover 2. Three hollow sleeves 1 are evenly spaced in the circumferential direction on the middle boss of the upper bearing chamber 3. Each sleeve 1 communicates with the inside of the upper bearing chamber 3. The bottom of each sleeve 1 is inserted into the corresponding threaded hole of the upper bearing chamber 3, and the sleeve 1 and the upper bearing chamber 3 are fixedly connected by threads. The bottom flange of the upper bearing chamber 3 and the top flange of the lower bearing chamber 7 are connected by connecting bolts 4, nuts 6, and gaskets 5. The bottom of the lower bearing chamber 7 is fixedly connected to the lower bearing end cover 11 by four bearing end cover bolts 18 evenly arranged in the circumferential direction. A cylindrical through hole communicating with the inside of the bearing chamber 7 is opened in the center of the lower bearing end cover 11. The dial 8 is fixed on the outer surface of the bottom of the lower bearing end cover 11.

[0028] As Figure 2 and Figure 1As shown, the top of the main gear shaft 12 is inserted into the cylindrical through-hole at the center of the upper bearing end cover 2, and the top of the main gear shaft 12 is supported on the inner wall of the top of the upper bearing chamber 3 by a deep groove ball bearing 15; and a lip seal 13 is provided between the top of the main gear shaft 12 and the upper bearing end cover 2 for sealing. The bottom of the main gear shaft 12 is inserted into the cylindrical through-hole at the center of the lower bearing end cover 11, and the bottom of the main gear shaft 12 is supported on the inner wall of the bottom of the lower bearing chamber 7 by a deep groove ball bearing 15; and a lip seal 13 is provided between the bottom of the main gear shaft 12 and the lower bearing end cover 11 for sealing. The main gear shaft 12, the upper bearing end cover 2, the upper bearing chamber 3, the lower bearing end cover 11, and the lower bearing chamber 7 are all coaxial. Three driven gear shafts 17 are provided in the cavity formed by the upper bearing chamber 3 and the lower bearing chamber 7. The driven gear shafts 17 are evenly arranged along the circumferential direction of the main gear shaft 12, and the gears in the middle of the three driven gear shafts 17 are all meshed with the gear in the middle of the main gear shaft 12. The bottoms of the three driven gear shafts 17 are all inserted into the bosses in the middle of the lower bearing chamber 7, and the bottoms of the three driven gear shafts 17 are all supported in the bosses of the bearing chamber 7 by self-lubricating bearings 16. The tops of the three driven gear shafts 17 all penetrate through the upper bearing chamber 3 and are inserted into their respective sleeves 1, and the driven gear shafts 17 and the sleeves 1 are all rotationally connected by threads. Snap rings 14 are sleeved outside the top and bottom of the main gear shaft 12, and the snap rings 14 are located between the lip seal 13 and the deep groove ball bearing 15. The function of the snap ring 14 is to fix the inner ring of the bearing on the main gear shaft 12 to prevent the deep groove ball bearing 15 from sliding down and disengaging from the main gear shaft 12.

[0029] As Figure 2 and Figure 1 shown, the bottom of the main gear shaft 12 is located outside the bearing chamber 7, and a ratchet sleeve 10 that is fixedly connected to it by threads is sleeved outside the bottom of the gear shaft 12; the bottom end of the main gear shaft 12 is inserted into the ratchet wrench 9, and the two are fixedly connected by threads. A dial 8 is sleeved outside the main gear shaft 12, and the pointer of the dial 8 is fixed on the main gear shaft 12.

[0030] As Figure 1 and Figure 2 shown, a method for lifting and lowering the pump shaft of a nuclear power plant seawater circulation pump, the specific steps of this method are as follows:

[0031] Step 1, install the pump shaft of the nuclear power plant seawater circulation pump into the sleeve 1 of the pump shaft lifting and lowering device

[0032] Install three super bolts on the upper and lower couplings of the seawater circulation pump, install the super nuts of the three super bolts, and finally sleeve the ends of the three sleeves 1 of the pump shaft lifting and lowering device outside the super nuts.

[0033] The seawater circulation pump coupling is the pump shaft of the seawater circulation pump.

[0034] Step 2, rotate the main gear shaft 12 of the pump shaft lifting and lowering device to drive the driven gear shafts 17 to rotate

[0035] Rotate the ratchet wrench 9, and the ratchet wrench 9 drives the main gear shaft 12 to rotate. The main gear shaft 12 transmits the force to the sub-gears in the middle of the three driven gear shafts 17 through the main gear in the middle thereof, that is, the main gear shaft 12 transmits the force to the driven gear shafts 17, and the three driven gear shafts 17 rotate together.

[0036] Step 3: The driven gear shaft 17 rotates, driving the sleeve 1 to rotate, thereby lifting the seawater circulation pump shaft upward

[0037] Under the rotation action, the three driven gear shafts 17 respectively drive the corresponding sleeves 1 to rotate, thereby tightening the three super nuts and three super bolts in the sleeves 1, and thus lifting the seawater circulation pump shaft upward.

[0038] A dial 8 is provided on the lower bearing end cover 11. When the main gear shaft 12 rotates, the pointer on the main gear shaft 12 can display the rotation degree on the dial 8. Rotating the same angle in the four directions of the seawater circulation pump shaft can ensure that the pump shaft rises by the same height each time, enabling the pump shaft to rise smoothly, and effectively avoiding the phenomenon of deviation during the rising process of the pump shaft, achieving the purpose of lifting the seawater circulation pump shaft.

[0039] The present invention has been described in detail above in conjunction with the drawings and embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention. The content not described in detail in the present invention can all adopt the prior art.

Claims

1. A device for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant, characterized in that: The device includes a sleeve (1), an upper bearing end cover (2), an upper bearing chamber (3), a lower bearing chamber (7), a ratchet wrench (9), a lower bearing end cover (11), a main gear shaft (12) and a driven gear shaft (17). An upper bearing end cover (2) is provided at the top of the upper bearing chamber (3), and a number of sleeves (1) communicating with its interior are provided circumferentially in the middle of the upper bearing chamber (3); the bottom of the upper bearing chamber (3) is connected to the top of the lower bearing chamber (7), and the two form a cavity; a lower bearing end cover (11) is provided at the bottom of the lower bearing chamber (7); the main gear shaft (12) and a number of driven gear shafts (17) are located in the cavity formed by the upper bearing chamber (3) and the lower bearing chamber (7), and the number of driven gear shafts (17) are evenly arranged circumferentially along the main gear shaft (12), and the main gear of the main gear shaft (12) meshes with the sub-gear of the driven gear shaft (17); through holes are opened in the centers of both the upper bearing end cover (2) and the lower bearing end cover (11), and the top and bottom of the main gear shaft (12) are respectively installed in the through holes in the centers of the upper bearing end cover (2) and the lower bearing end cover (11); the end of the bottom of the main gear shaft (12) is fixedly connected to the ratchet wrench (9); the bottom of the driven gear shaft (17) is located inside the inner wall of the lower bearing chamber (7), and the top of the driven gear shaft (17) is located inside the sleeve (1); the main gear shaft (12), the upper bearing end cover (2), the upper bearing chamber (3), the lower bearing end cover (11), and the lower bearing chamber (7) are all coaxial; lip seals (13) are provided between the top of the main gear shaft (12) and the inner wall of the upper bearing end cover (2), and between the bottom of the main gear shaft (12) and the inner wall of the lower bearing end cover (11); snap rings (14) are sleeved outside both the top and bottom of the main gear shaft (12), and the snap rings (14) are located between the lip seals (13) and the deep groove ball bearings (15); the snap rings (14) fix the inner ring of the bearing on the main gear shaft (12) to prevent the deep groove ball bearings (15) from sliding down and disengaging from the main gear shaft (12); deep groove ball bearings (15) are provided between the top of the main gear shaft (12) and the inner wall of the upper bearing end cover (2), and between the bottom of the main gear shaft (12) and the inner wall of the lower bearing end cover (11); a self-lubricating bearing (16) is provided between the bottom of the driven gear shaft (17) and the lower bearing chamber (7); a dial (8) is provided on the outer surface of the bottom of the lower bearing end cover (11), and the dial (8) is sleeved outside the main gear shaft (12).

2. A device for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant according to claim 1, characterized in that: The pointer of the dial (8) is fixed at a position corresponding to the dial (8) on the main gear shaft (12).

3. A device for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant according to claim 2, characterized in that: The bottom of the main gear shaft (12) is fixedly connected to the ratchet wrench (9) through a ratchet sleeve (10).

4. A device for lifting and lowering the pump shaft of a seawater circulation pump in a nuclear power plant according to claim 3, characterized in that: The bottom flange of the upper bearing chamber (3) is connected to the top flange of the lower bearing chamber (7).

5. A lifting method for a lifting device of a pump shaft of a nuclear power plant seawater circulation pump according to any one of the above claims 1 to 4, characterized in that: The specific steps of this method are as follows: Step 1: Install the pump shaft of the nuclear power plant seawater circulation pump into the sleeve (1) of the pump shaft lifting device; In step 1, install the super bolt on the pump shaft of the seawater circulation pump, install the super nut of the super bolt, and sleeve the sleeve (1) of the pump shaft lifting device outside the super nut; Step 2: Rotate the main gear shaft (12) of the pump shaft lifting device to drive the driven gear shaft (17) to rotate; in step 2, the ratchet wrench (9) drives the main gear shaft (12) to rotate, and the main gear shaft (12) transmits the force to the driven gear shaft (17); Step 3: The driven gear shaft (17) rotates to drive the sleeve (1) to rotate, thereby lifting the pump shaft of the nuclear power plant seawater circulation pump upward; in step 3, when the main gear shaft (12) rotates, the pointer on the main gear shaft (12) can display the rotation degree on the dial (8); according to the rotation degree, the pump shaft of the seawater circulation pump is rotated by the same angle in each direction at the same time, ensuring that the pump shaft rises by the same height each time, and realizing the lifting of the pump shaft of the seawater circulation pump.

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