Permanent magnet contactless transmission device for vertical reducer and drum net of nuclear power plant

Abstract

This utility model discloses a permanent magnet contactless transmission device for a nuclear power plant standing reducer and drum screen, comprising a permanent magnet contactless transmission module, a support module, and a push-pull maintenance platform module. This permanent magnet contactless transmission device for a nuclear power plant standing reducer and drum screen integrates the permanent magnet contactless transmission module, the support module, and the push-pull maintenance platform module to construct a complete transmission and support system. The permanent magnet contactless transmission module achieves contactless torque transmission, fundamentally cutting off the vibration path transmitted from the drum screen to the reducer. The support module, through symmetrical layout and the cooperation of anti-rotation torque arms, eliminates the center of gravity shift caused by single-sided suspension, enhancing the operating stability of the reducer. The push-pull maintenance platform module enables quick disengagement or docking of the vertical reducer and the drum screen drive shaft, significantly improving maintenance convenience. The synergistic effect of these three components effectively solves the core problems of vibration transmission, structural instability, and inconvenient maintenance in existing technologies.

Description

Technical Field

[0001] This utility model relates to the field of transmission in nuclear power plant circulating water filtration systems, and in particular to a permanent magnet non-contact transmission device for a nuclear power plant standing reducer and a drum screen. Background Technology

[0002] The circulating water filtration (CFI) system in many nuclear power plants provides all filtered seawater to the nuclear power units. The seawater is filtered after passing through a drum screen. The transmission path is motor-reducer-drum screen. Each unit contains two rows of drum screens, and each row of drum screens is driven by an independent vertically suspended reducer unit. Both drum screen reducers are vertically structured. The reducer is driven by three motors: two low-speed motors at the bottom (one in use and one on standby), and one medium / high-speed motor at the top.

[0003] Vertically arranged reducers have a high failure rate. Problems such as excessive vibration of the drive motor, worm gear breakage, reducer overheating, worm wheel wear, bearing breakage, and lock bolt breakage have occurred many times. When the reducer unit fails, it will cause the drum screen to stop operating, resulting in an increase in the drum screen pressure differential, unit shutdown and reactor shutdown, affecting the safety of SEC water intake, and seriously threatening the nuclear safety of the power plant.

[0004] Extensive statistical analysis and multiple on-site measurements of the CFI reducer's vibration modes indicate that downstream drum screen vibration is caused by factors such as eccentricity, tide level changes, pinion wear, and unit power variations. This vibration is transmitted in reverse through the drum screen drive shaft to the reducer, leading to reducer bearing damage, oil leaks, abnormal noise, and temperature rise. The rigid connection between the vertically suspended reducer and the drum screen drive shaft is the root cause of the vertical reducer's failure. Therefore, there is an urgent need for a permanent magnet drive device specifically designed for nuclear power plant CFI systems, combining vibration isolation and structural stability, to address the problems of vibration transmission and insufficient structural stability in existing technologies. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a permanent magnet non-contact transmission device for a nuclear power plant standing reducer and a drum screen.

[0006] The technical solution adopted by this utility model to solve its technical problem is: to construct a permanent magnet non-contact transmission device for a nuclear power plant standing reducer and a drum screen, which includes a permanent magnet non-contact transmission module, a support module and a push-pull maintenance platform module. The permanent magnet contactless transmission module is connected between the output shaft of the vertical reducer and the drum mesh drive shaft, and is used to realize torque transmission between the output shaft of the vertical reducer and the drum mesh drive shaft through magnetic coupling. The support module includes two bearing seat brackets, a concrete foundation connection, and an anti-rotation torque arm. The two bearing seat brackets are symmetrically placed on both sides of the vertical reducer and installed on the concrete foundation connection. The push-pull maintenance platform module includes a steel structure base, a slide rail system, a drive mechanism, and limit blocks. The concrete foundation connection is installed on the steel structure base. One end of the anti-rotation torque arm is connected to the housing of the vertical reducer, and the other end of the anti-rotation torque arm is hinged to the concrete foundation connection. The slide rail system is installed on the floor. The drive mechanism is used to drive the steel structure base to move horizontally on the slide rail system. The limit blocks are set on both sides of the steel structure base.

[0007] In some embodiments, the permanent magnet contactless transmission module includes an inner rotor, an outer rotor, and an air gap isolation layer. The inner rotor is fixed to the end of the output shaft of the vertical reducer, the outer rotor is fixed to the end of the drum mesh drive shaft, and the air gap isolation layer is the radial gap between the inner rotor and the outer rotor.

[0008] In some embodiments, the inner rotor is embedded with a rare earth permanent magnet, which is a neodymium iron boron N52H grade magnet.

[0009] In some embodiments, the outer rotor is fitted with a magnetic conductor, which is electrical pure iron DT4.

[0010] In some embodiments, the radial clearance between the inner rotor and the outer rotor is 1 mm to 5 mm.

[0011] In some embodiments, the slide rail system includes two parallel H-shaped guide rails, the width of which is 100mm to 140mm.

[0012] In some embodiments, the bottom of the steel structure base is provided with a slider, which is embedded in an H-shaped guide rail.

[0013] In some embodiments, the drive mechanism is a manual crank or an electric actuator.

[0014] In some embodiments, the manual crank is configured with a worm gear reducer.

[0015] In some embodiments, the bearing housing support is equipped with a deep groove ball bearing, a self-aligning ball bearing, a cylindrical roller bearing, or an angular contact ball bearing.

[0016] The present invention offers the following advantages: The permanent magnet contactless transmission device for the nuclear power plant's standing reducer and drum screen integrates a permanent magnet contactless transmission module, a support module, and a push-pull maintenance platform module, constructing a complete transmission and support system. The permanent magnet contactless transmission module achieves contactless torque transmission, fundamentally cutting off the vibration path transmitted from the drum screen to the reducer. The support module, through its symmetrical layout and the cooperation of anti-rotation torque arms, eliminates the center of gravity shift caused by single-sided suspension, enhancing the reducer's operational stability. The push-pull maintenance platform module enables rapid disengagement or docking of the vertical reducer and the drum screen drive shaft, significantly improving maintenance convenience. The synergistic effect of these three components effectively solves the core problems of vibration transmission, structural instability, and inconvenient maintenance in existing technologies, ensuring the safe and stable operation of the nuclear power plant's CFI system. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this utility model, the present utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of this utility model and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the permanent magnet non-contact transmission device for the nuclear power plant standing reducer and the drum screen in some embodiments of this utility model; Figure 2 This is a partial structural schematic diagram of the permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen in some embodiments of this utility model; Figure 3 This is a structural schematic diagram of the housing of the vertical reducer in some embodiments of this utility model. Detailed Implementation

[0018] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or component referred to must have a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0019] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0020] Please see Figures 1 to 3 This is a permanent magnet non-contact transmission device for a nuclear power plant standing reducer and a drum screen in some embodiments of the present invention, which includes a permanent magnet non-contact transmission module 1, a support module 2, and a push-pull maintenance platform module 3. The permanent magnet contactless transmission module 1 is connected between the output shaft 41 of the vertical reducer and the drum mesh drive shaft 42, and is used to realize torque transmission between the output shaft 41 of the vertical reducer and the drum mesh drive shaft 42 through magnetic coupling. The support module 2 includes two bearing seat brackets 21, a concrete foundation connection part 22 and an anti-rotation torque arm 23. The two bearing seat brackets 21 are symmetrically placed on both sides of the vertical reducer and installed on the concrete foundation connection part 22. The push-pull maintenance platform module 3 includes a steel structure base 31, a slide rail system 32, a drive mechanism 33 and a limit block 34. The concrete foundation connection part 22 is installed on the steel structure base 31. One end of the anti-rotation torque arm 23 is connected to the housing 43 of the vertical reducer, and the other end of the anti-rotation torque arm 23 is hinged to the concrete foundation connection part 22. The slide rail system 32 is installed on the floor. The drive mechanism 33 is used to drive the steel structure base 31 to move horizontally on the slide rail system 32. The limit block 34 is set on both sides of the steel structure base 31.

[0021] Specifically, the permanent magnet contactless transmission module 1 is connected between the output shaft 41 of the vertical reducer and the drum mesh drive shaft 42, replacing the traditional rigid or flexible coupling. Its core function is to complete power transmission through magnetic coupling. The torque of the output shaft 41 of the vertical reducer is transmitted to the drum mesh drive shaft 42 through magnetic force, driving the drum mesh to rotate. This non-contact transmission method completely cuts off the transmission path of vibrations caused by seawater disturbance and eccentric loads to the reducer, fundamentally avoiding damage to reducer components caused by vibration. The support module 2 is a support unit to ensure the stable operation of the vertical reducer. Two bearing seat brackets 21 are symmetrically placed on both sides of the vertical reducer. The bearing seat brackets 21 support the output shaft 41 of the vertical reducer through bearings. The two bearing seat brackets 21 form a double-support structure, replacing the traditional single-sided suspension method, balancing the center of gravity of the vertical reducer, and eliminating swaying caused by unilateral force. The concrete foundation connection 22 rigidly connects the bearing housing bracket 21 to the steel structure base 31, ensuring the stability of the support structure and preventing displacement of the bearing housing bracket 21 during operation. One end of the anti-rotation torque arm 23 is connected to the vertical reducer housing 43, and the other end is hinged to the concrete foundation connection 22, forming a limit to fix the position of the vertical reducer housing 43. This ensures that the vertical reducer output shaft 41 only transmits power, keeping the vertical reducer housing 43 stationary, guaranteeing normal operation of the transmission system, and further improving structural stability. The steel structure base 31 serves as a load-bearing platform. Made of steel, the steel structure base 31 integrates the vertical reducer, drive motor, and support module 2, achieving integrated equipment design. The slide rail system 32 is installed on the floor, providing movement guidance for the steel structure base 31. The drive mechanism 33 drives the steel structure base 31 to move along the slide rail system 32, enabling rapid disengagement or docking of the vertical reducer output shaft 41 with the drum drive shaft 42. Limiting blocks 34 prevent the steel structure base 31 from moving out of position and ensure operational safety. Specifically, the limiting blocks 34 are welded L-shaped steel plates on both sides of the steel structure base 31.

[0022] Understandably, the permanent magnet contactless transmission device for the nuclear power plant's standing reducer and drum screen integrates a permanent magnet contactless transmission module 1, a support module 2, and a push-pull maintenance platform module 3 to construct a complete transmission and support system. The permanent magnet contactless transmission module 1 achieves contactless torque transmission, fundamentally cutting off the vibration path transmitted from the drum screen to the reducer. The support module 2, through its symmetrical layout and the cooperation of the anti-rotation torque arm 23, eliminates the center of gravity shift caused by single-sided suspension, enhancing the reducer's operational stability. The push-pull maintenance platform module 3 enables rapid disengagement or docking of the vertical reducer and the drum screen drive shaft 42, significantly improving maintenance convenience. The synergistic effect of these three components effectively solves the core problems of vibration transmission, structural instability, and inconvenient maintenance in existing technologies, ensuring the safe and stable operation of the nuclear power plant's CFI system.

[0023] like Figure 2As shown, the permanent magnet contactless transmission module 1 includes an inner rotor 11, an outer rotor 12, and an air gap isolation layer 13. The inner rotor 11 is fixed to the end of the output shaft 41 of the vertical reducer, and the outer rotor 12 is fixed to the end of the drum mesh drive shaft 42. The air gap isolation layer 13 is the radial gap between the inner rotor 11 and the outer rotor 12. The structural design of fixing the inner rotor 11 to the output shaft 41 of the vertical reducer and fixing the outer rotor 12 to the drum mesh drive shaft 42 ensures the stability of torque transmission; the setting of the air gap isolation layer 13 realizes completely contactless transmission and completely blocks the vibration transmission path. In some embodiments, the permanent magnet contactless transmission module 1 can be in the form of dual disks.

[0024] The inner rotor 11 is equipped with rare-earth permanent magnets, which are neodymium iron boron N52H grade. The selection of neodymium iron boron N52H grade rare-earth permanent magnets is due to their high energy product and high coercivity, enabling them to provide sufficient magnetic coupling torque in a non-contact state, meeting the power transmission requirements of the nuclear power plant's drum grid drive. Furthermore, their high stability makes them suitable for the harsh operating environment of nuclear power plants, extending the service life of the equipment.

[0025] The outer rotor 12 is fitted with a magnetic conductor, which is made of electrical pure iron DT4. Using electrical pure iron DT4 as the magnetic conductor is advantageous because it has high permeability and low coercivity, enabling it to efficiently respond to the magnetic force of rare-earth permanent magnets, improving magnetic coupling efficiency, ensuring smooth torque transmission, and thus guaranteeing the stability of the drum mesh drive. This avoids power loss or transmission failure caused by insufficient magnetic conductivity.

[0026] The radial gap between the inner rotor 11 and the outer rotor 12 is 1mm to 5mm. This gap range ensures effective transmission of magnetic coupling, avoids insufficient torque transmission due to excessive gap, and provides buffer space for thermal expansion and slight displacement during equipment operation, preventing physical contact between the inner rotor 11 and the outer rotor 12. It also effectively isolates vibration, balancing transmission reliability and vibration isolation. In this embodiment, the radial gap between the inner rotor 11 and the outer rotor 12 is preferably 3mm.

[0027] The slide rail system 32 includes two parallel H-shaped guide rails, each with a width ranging from 100mm to 140mm. The H-shaped guide rails offer high structural strength and good guiding accuracy, and their parallel arrangement ensures the stability of the steel structure base 31 during movement. The width range is suitable for the equipment weight and installation space requirements of nuclear power plant CFI systems, ensuring both the load-bearing capacity of the guide rails and avoiding space waste due to excessively wide rails, thus improving the site adaptability of the device. In this embodiment, the width of the H-shaped guide rails is preferably 120mm. In some embodiments, the slide rail system 32 may be equipped with circular guide rails, allowing the steel structure base 31 to rotate 90 degrees.

[0028] The bottom of the steel structure base 31 is equipped with a slider, which is embedded in the H-shaped guide rail. The slider at the bottom of the steel structure base 31 is fitted into the H-shaped guide rail. This fit reduces the friction during the movement of the steel structure base 31, making the movement of the steel structure base 31 smoother and less strenuous.

[0029] The drive mechanism 33 can be either a manual crank or an electric actuator. The drive mechanism 33 offers two options: a manual crank and an electric actuator. The manual crank is suitable for small-range movements or scenarios without power supply, offering flexible and convenient operation. The electric actuator is suitable for scenarios requiring rapid movement or heavy loads, improving movement efficiency. Both drive methods adapt to different nuclear power plant site conditions and maintenance needs, enhancing the versatility and practicality of the device. The manual crank is equipped with a worm gear reducer, which reduces speed and increases force, reducing the effort required for manual operation and making it easier for workers to move the steel structure base 31. Simultaneously, the worm gear structure has a self-locking function, preventing accidental slippage of the steel structure base 31 after it stops moving, improving operational safety.

[0030] The bearing housing bracket 21 is equipped with deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearings, or angular contact ball bearings. Deep groove ball bearings are suitable for high-speed, low-noise applications; self-aligning ball bearings can compensate for coaxiality errors; cylindrical roller bearings have high load-carrying capacity; and angular contact ball bearings can withstand combined radial and axial loads. This variety of bearing options adapts to the operating conditions and load requirements of different nuclear power plant CFI systems, enhancing the adaptability and flexibility of the equipment, while also facilitating the selection of readily available and cost-effective bearing types based on equipment maintenance needs.

[0031] The working process of this embodiment is as follows: During normal operation, the motor drives the reducer to run. The output shaft 41 of the vertical reducer drives the drum mesh drive shaft 42 to rotate through the magnetic coupling of the permanent magnet contactless transmission module 1, thereby driving the drum mesh to work. The vibration generated by the drum mesh is blocked by the air gap isolation layer 13 and cannot be transmitted to the reducer. The support module 2 ensures that the reducer runs stably without shaking. When maintenance is required, loosen the relevant fixing bolts, start the electric push rod or manual crank to drive the steel structure base 31 to move along the H-shaped guide rail, so that the output shaft 41 of the vertical reducer and the drum mesh drive shaft 42 are separated through the permanent magnet contactless transmission module 1. The steel structure base 31 can be moved out of the maintenance area for reducer maintenance or replacement. After maintenance is completed, reverse the drive of the steel structure base 31 to move it, so that the output shaft 41 of the vertical reducer and the drum mesh drive shaft 42 are precisely connected to complete the assembly.

[0032] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A permanent magnet non-contact transmission device for a nuclear power plant standing reducer and a drum mesh, characterized in that, It includes a permanent magnet contactless transmission module (1), a support module (2), and a push-pull maintenance platform module (3). The permanent magnet contactless transmission module (1) is connected between the output shaft (41) of the vertical reducer and the drum mesh drive shaft (42) to realize torque transmission between the output shaft (41) of the vertical reducer and the drum mesh drive shaft (42) through magnetic coupling; The support module (2) includes two bearing seat brackets (21), a concrete foundation connection part (22), and an anti-rotation torque arm (23). The two bearing seat brackets (21) are symmetrically placed on both sides of the vertical reducer and installed on the concrete foundation connection part (22). The push-pull maintenance platform module (3) includes a steel structure base (31), a slide rail system (32), a drive mechanism (33), and a limit block (34). The concrete foundation connection part (22) is installed on the steel structure base (31). One end of the anti-rotation torque arm (23) is connected to the housing (43) of the vertical reducer, and the other end of the anti-rotation torque arm (23) is hinged to the concrete foundation connection part (22). The slide rail system (32) is installed on the floor. The drive mechanism (33) is used to drive the steel structure base (31) to move horizontally on the slide rail system (32). The limit block (34) is set on both sides of the steel structure base (31).

2. The permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen according to claim 1, characterized in that, The permanent magnet contactless transmission module (1) includes an inner rotor (11), an outer rotor (12) and an air gap isolation layer (13). The inner rotor (11) is fixed to the end of the output shaft (41) of the vertical reducer, the outer rotor (12) is fixed to the end of the drum mesh drive shaft (42), and the air gap isolation layer (13) is the radial gap between the inner rotor (11) and the outer rotor (12).

3. The permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen according to claim 2, characterized in that, The inner rotor (11) is fitted with a rare earth permanent magnet, which is a neodymium iron boron N52H grade magnet.

4. The permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen according to claim 2, characterized in that, The outer rotor (12) is fitted with a magnetic conductor, which is electrical pure iron DT4.

5. The permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen according to claim 2, characterized in that, The radial gap between the inner rotor (11) and the outer rotor (12) is 1 mm to 5 mm.

6. The permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen according to claim 1, characterized in that, The slide rail system (32) includes two parallel H-shaped guide rails with a width of 100mm to 140mm.

7. The permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen according to claim 6, characterized in that, The bottom of the steel structure base (31) is provided with a slider, which is embedded in the H-shaped guide rail.

8. The permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen according to claim 1, characterized in that, The drive mechanism (33) is a manual crank or an electric push rod.

9. The permanent magnet non-contact transmission device for a nuclear power plant standing reducer and a drum screen according to claim 8, characterized in that, The manual crank is equipped with a worm gear reducer.

10. The permanent magnet non-contact transmission device for the nuclear power plant standing reducer and drum screen according to claim 1, characterized in that, The bearing housing bracket (21) is equipped with a deep groove ball bearing, a self-aligning ball bearing, a cylindrical roller bearing, or an angular contact ball bearing.

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