Nuclear-grade cantilever type centrifugal pump overturning maintenance platform

Abstract

The invention belongs to the technical field of nuclear power plant pump equipment maintenance, and particularly relates to a nuclear-grade cantilever type centrifugal pump overturning maintenance platform. Comprising a lifting platform, a base, a bearing box, a flange shaft, a split-half connecting plate, a plum coupling, a worm and gear transmission box and a hand wheel. The lifting type platforms are installed on the two sides of the base, the bearing boxes and the worm and gear transmission boxes are installed at the two ends of the base, the bearing boxes support the flange shafts at the two ends, the flange shafts are connected with the split-half connecting plates, the split-half connecting plates are connected with the overhauling parts, and the plum coupling is connected with the flange shaft on the right side and a worm gear shaft in the worm and gear transmission boxes. And the hand wheel is connected with a worm of the worm and gear transmission box. According to the invention, the working efficiency of on-site maintenance is improved, waste of construction period and manpower caused by repeated hoisting in the disassembly and assembly process is avoided, and meanwhile, the operation risk is also greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power plant pump equipment maintenance, and in particular relates to a nuclear-grade cantilever centrifugal pump turnover maintenance platform. Background Art

[0002] The existing disassembly and overhaul method for nuclear-grade service water pumps in nuclear power plants is as follows: Lift the overhauled component and place it vertically on the overhaul site, then remove the coupling. Turn the component 90° to a horizontal position, loosen the impeller nut, and then flip the component so the impeller faces downward. Slowly remove the impeller nut and impeller. Turn the component 180° and measure the ring clearance. Turn the component 180° and remove the lower pump cover. Remove the drive-end bearing gland and measure the drive-end bearing gland clearance. Install a lifting lug on the shaft head and lift out the pump shaft. Turn the component 180° and measure the non-drive-end bearing gland clearance. Remove the non-drive-end bearing. Remove the rotor sleeves and other components and measure their data. After cleaning all components, reassemble the equipment in the reverse order of disassembly.

[0003] Problems with existing plant water pump disassembly methods: 1) The pump is a large vertical centrifugal pump with many parts, and the disassembly and assembly process is relatively complicated, with a long construction period. In addition, this work is I0 work in a nuclear power plant and must be completed within a limited construction period; 2) The pump is heavy, and the pump often needs to be flipped multiple times during the disassembly and assembly process, which requires frequent coordination and long waiting times for lifting personnel, easily resulting in serious waste of construction time and manpower; 3) Flipping the pump multiple times requires repeated work such as tying slings, disassembling and assembling lifting ears, and crane hoisting, increasing the risk of lifting injuries and equipment damage; 4) The process of flipping the pump body requires the cooperation of at least two hand hoists, which requires high skills from the commander and rope operator; 5) The entire maintenance process has many overlapping disciplines, which is difficult to control and prone to human errors.

[0004] In summary, the disassembly and assembly process of existing cantilever centrifugal pumps is cumbersome, requiring frequent crane work to flip the pump. This not only wastes time and manpower, but also poses risks of equipment damage and personal injury. To facilitate, quickly, safely, and effectively perform pump maintenance, a new tooling and method are urgently needed to address these issues. Summary of the Invention

[0005] The purpose of the present invention is to provide a nuclear-grade cantilever centrifugal pump turnover maintenance platform to improve the efficiency of on-site maintenance, avoid the waste of time and manpower caused by repeated lifting during disassembly and assembly, and also greatly reduce operational risks.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: A nuclear-grade cantilever centrifugal pump turnover maintenance platform includes a lifting platform, a base, a bearing box, a flange shaft, a half-connecting plate, a plum blossom coupling, a worm gear transmission box, and a handwheel; the lifting platform is installed on both sides of the base, the bearing boxes and the worm gear transmission box at both ends are installed on the base, the bearing boxes support the flange shafts at both ends, the flange shafts are connected to the half-connecting plates, the half-connecting plates are connected to the maintenance components, the plum blossom coupling is connected to the right flange shaft and the worm shaft in the worm gear transmission box, and the handwheel is connected to the worm of the worm gear transmission box.

[0007] The lifting platform serves as a place for maintenance personnel to stand and perform maintenance. There are guardrails on the lifting platform for hanging safety belt hooks.

[0008] The guardrail is hydraulically controlled to be raised and lowered, making it easy for personnel to adjust the height for equipment maintenance.

[0009] There are two lifting platforms on each side.

[0010] The three welded pillars on the base are used to install the bearing box and worm gear box at both ends respectively.

[0011] The half connecting plate is connected to the flange shaft through flanges at both ends, and the half connecting plate is connected to the maintenance component through bolt holes on the end surface.

[0012] The two half connecting plates are connected and fixed via bolt holes on the sides.

[0013] The worm of the worm gear transmission box is placed at the bottom and is used to drive the upper gear shaft, thereby driving the flange shaft and maintenance parts to flip.

[0014] Turn the handwheel to adjust the half connecting plate to the horizontal level, lift the maintenance component and connect the half connecting plate to the pump cover with bolts, adjust the lifting platform to the impeller installation position, loosen the impeller nut, slowly remove the impeller nut and impeller, lift the lifting platform to the bearing chamber installation position, unscrew the connecting studs between the pump cover and the bearing body, loosen the stuffing gland, remove the lower pump cover, take out the stuffing, stuffing ring, and sand retaining ring, lift the lifting platform to the pump shaft head position, remove the pump coupling, remove the drive end bearing gland, measure the drive end bearing gland clearance, install the lifting lug on the shaft head, lift the rotor out and move it to the maintenance site, lower the lifting platform to the impeller installation position, turn the handwheel to flip the maintenance component 180°, measure the non-drive end bearing gland clearance, remove the non-drive end bearing gland and bearing, remove the rotor sleeve components and perform data measurement.

[0015] After cleaning all parts, reinstall them in the reverse order of disassembly, lift the pump from the maintenance platform and transport it back to the pump pit, and the work is completed.

[0016] The beneficial effects achieved by the present invention are: The cantilever centrifugal pump turnover maintenance platform of the present invention is used to dismantle and assemble the centrifugal pump, making on-site maintenance work simple and efficient. Its advantages mainly include the following aspects: (1) Optimized maintenance method: The maintenance platform is equipped with a lifting platform with guardrails. At the same time, the equipment is initially installed at a higher position, which is convenient for maintenance at the bottom and top of the equipment, avoiding multiple flips. The dismantling work can be completed by simply adjusting the height of the lifting platform and flipping it once.

[0017] (2) Reduced workload: Using the platform to dismantle and assemble equipment greatly reduces the need for cooperation from lifting personnel. Lifting personnel do not need to repeatedly perform tasks such as tying slings, disassembling and assembling lifting lugs, and crane lifting, thus reducing workload.

[0018] (3) Shortened construction period: Using the platform for maintenance greatly reduces the number of times the equipment is flipped. At the same time, maintenance personnel can flip the equipment by themselves, and the flipping is convenient, avoiding the waste of construction time caused by pausing work after executing one step and waiting for the crane personnel to flip the equipment before continuing to work, thus greatly shortening the construction period.

[0019] (4) Lowering the skill threshold: Using this platform to flip the equipment is simple to operate and can be adjusted at will, avoiding the problem of needing at least two hand hoists to cooperate in the process of flipping the pump body, thus lowering the skill threshold.

[0020] (5) Save manpower: When using this platform to flip the equipment, only one person is needed to operate the handwheel, while the original method requires at least five people to perform the flipping operation - one crane commander, one crane driver, at least two crane rope operators, and one maintenance personnel to cooperate, which greatly saves manpower.

[0021] (6) Reduced maintenance risks: The maintenance platform makes the previously cumbersome maintenance process simpler, faster, more intuitive and controllable, reduces multi-disciplinary cross-work, and reduces the risk of equipment damage and personal injury caused by human error. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of a nuclear-grade cantilever centrifugal pump turnover maintenance platform; Figure 2 A schematic diagram of the use of a nuclear-grade cantilever centrifugal pump turnover maintenance platform; In the figure: 1-lifting platform; 2-base; 3-bearing box; 4-flange shaft; 5-half connecting plate; 6-plum blossom coupling; 7-worm gear transmission box; 8-handwheel. The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1The figure shows a nuclear-grade cantilever centrifugal pump tilting maintenance platform, comprising a lifting platform 1, a base 2, a bearing housing 3, a flange shaft 4, a split connecting plate 5, a plum blossom coupling 6, a worm gear transmission box 7, and a handwheel 8. The lifting platform 1 serves as a standing position for maintenance personnel. It has guardrails for hanging safety belt hooks. These guardrails are hydraulically controlled and can be raised and lowered to facilitate personnel adjusting the height for equipment maintenance. The platform is mounted on two sides of the base 2, two on each side, to facilitate coordination among maintenance personnel. The base 2 serves as the foundation for the tilting portion of the maintenance platform. Three welded struts are used to mount the bearing housing 3 and worm gear transmission box 7 at each end. The bearing housing 3 supports the flange shaft 4 at each end. The flange shaft 4 connects to the split connecting plate 5. The split connecting plate 5 connects to maintenance components. The split connecting plate 5 is connected to the flange shaft 4 via flanges at both ends and to the maintenance components via bolt holes on the end faces. The two split connecting plates 5 are secured together via bolt holes on the sides. The plum blossom coupling 6 is used to connect the right flange shaft 4 and the worm shaft in the worm gear transmission box 7. The worm of the worm gear transmission box 7 is placed at the bottom, used to drive the upper gear shaft, thereby driving the flange shaft 4 and the maintenance parts to flip, and has a self-locking feature to ensure that the parts can be flipped as needed. The handwheel 8 is connected to the worm of the worm gear transmission box 7 to drive the worm, thereby driving the upper gear shaft to rotate. The right flange shaft 4 is connected to the worm gear transmission box 7 through the plum blossom coupling 6, and the other parts are all bolted to facilitate disassembly and assembly. Figure 2 The figure shows how to use a turnover platform for a nuclear-grade cantilever centrifugal pump: Turn handwheel 8 to horizontally adjust the connecting plate 5, lift the inspection component, and bolt the connecting plate 5 to the pump cover. Adjust the lifting platform 1 to the impeller installation position (position A in the figure), loosen the impeller nut, and slowly remove the impeller nut and impeller. Raise the lifting platform 1 to the bearing housing installation position (position B in the figure), unscrew the studs connecting the pump cover and the bearing body, and loosen the packing gland. Remove the lower pump cover and remove the packing, packing ring, and sand deflector. Raise the lifting platform 1 to the pump shaft end position (position C in the figure) and remove the pump coupling. Remove the drive-end bearing gland and measure the drive-end bearing gland clearance. Install lifting lugs on the shaft end and lift the rotor to the inspection site. Lower the lifting platform 1 to the impeller installation position, turn handwheel 8 to rotate the component 180°, measure the non-drive-end bearing gland clearance, and remove the non-drive-end bearing gland and bearing. Remove the rotor sleeve components and perform data measurements. After cleaning all parts, reinstall them in the reverse order of disassembly. Lift the pump from the maintenance platform and transport it back to the pump pit. The work is completed.

Claims

1. A nuclear-grade cantilever centrifugal pump turnover maintenance platform, characterized by: It includes a lifting platform, a base, a bearing box, a flange shaft, a half-connecting plate, a plum blossom coupling, a worm gear transmission box, and a handwheel; the lifting platform is installed on both sides of the base, the bearing boxes and worm gear transmission boxes at both ends are installed on the base, the bearing boxes support the flange shafts at both ends, the flange shaft is connected to the half-connecting plate, the half-connecting plate is connected to the maintenance parts, the plum blossom coupling is connected to the right flange shaft and the worm shaft in the worm gear transmission box, and the handwheel is connected to the worm of the worm gear transmission box.

2. The nuclear-grade cantilever centrifugal pump turnover maintenance platform according to claim 1 is characterized by: The lifting platform serves as a place for maintenance personnel to stand and perform maintenance. There are guardrails on the lifting platform for hanging safety belt hooks.

3. The nuclear-grade cantilever centrifugal pump turnover maintenance platform according to claim 2 is characterized by: The guardrail is hydraulically controlled to be raised and lowered, making it easy for personnel to adjust the height for equipment maintenance.

4. The nuclear-grade cantilever centrifugal pump turnover maintenance platform according to claim 1 is characterized by: There are two lifting platforms on each side.

5. The nuclear-grade cantilever centrifugal pump turnover maintenance platform according to claim 1 is characterized in that: The three welded pillars on the base are used to install the bearing box and worm gear box at both ends respectively.

6. The nuclear-grade cantilever centrifugal pump turnover maintenance platform according to claim 1 is characterized by: The half connecting plate is connected to the flange shaft through flanges at both ends, and the half connecting plate is connected to the maintenance component through bolt holes on the end surface.

7. The nuclear-grade cantilever centrifugal pump turnover maintenance platform according to claim 1 is characterized by: The two half connecting plates are connected and fixed via bolt holes on the sides.

8. The nuclear-grade cantilever centrifugal pump turnover maintenance platform according to claim 1 is characterized by: The worm of the worm gear transmission box is placed at the bottom and is used to drive the upper gear shaft, thereby driving the flange shaft and maintenance parts to flip.

9. A method for overturning and repairing a nuclear-grade cantilever centrifugal pump, characterized in that: Turn the handwheel to adjust the half connecting plate to the horizontal level, lift the maintenance component and connect the half connecting plate to the pump cover with bolts, adjust the lifting platform to the impeller installation position, loosen the impeller nut, slowly remove the impeller nut and impeller, lift the lifting platform to the bearing chamber installation position, unscrew the connecting studs between the pump cover and the bearing body, loosen the stuffing gland, remove the lower pump cover, take out the stuffing, stuffing ring, and sand retaining ring, lift the lifting platform to the pump shaft head position, remove the pump coupling, remove the drive end bearing gland, measure the drive end bearing gland clearance, install the lifting lug on the shaft head, lift the rotor out and move it to the maintenance site, lower the lifting platform to the impeller installation position, turn the handwheel to flip the maintenance component 180°, measure the non-drive end bearing gland clearance, remove the non-drive end bearing gland and bearing, remove the rotor sleeve components and perform data measurement.

10. The method for overturning and repairing a nuclear-grade cantilever centrifugal pump according to claim 9, characterized in that: After cleaning all parts, reinstall them in the reverse order of disassembly, lift the pump from the maintenance platform and transport it back to the pump pit, and the work is completed.

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