Cutting and back gouging device for shielding main pump upper c-ring of nuclear power plant

Abstract

The application provides a shielding main pump upper C-shaped ring cutting and root cleaning device for a nuclear power plant, which comprises a cart system, a trolley system, a motor system and a cutter system; the cart system comprises a cart walking driving mechanism and a track guiding mechanism, wherein the track guiding mechanism is engaged with an external track laid on the upper end surface of a pump shell flange and is clamped on the external track; the trolley system comprises a trolley base and a radial feeding mechanism, and the radial feeding mechanism is configured to drive the trolley system to move radially along the upper end surface of the pump shell flange; the cutter system is connected with the motor system and is connected with a cutter, and the cutter disc plane of the cutter is parallel to the upper end surface of the pump shell flange. The device simplifies the process flow of the shielding main pump upper C-shaped ring cutting and root cleaning, simultaneously realizes the cutting and root cleaning, saves manpower and reduces the radiation dose of operating personnel, reduces the equipment procurement cost, and simultaneously simplifies the structure to make the equipment occupy smaller storage space, and is convenient for the operation of device maintenance and repair personnel.

Description

Technical Field

[0001] This application relates to the field of nuclear power plant shielded main pump maintenance technology, and in particular to a C-ring cutting and root cleaning device for the upper part of a nuclear power plant shielded main pump. Background Technology

[0002] The main coolant pump in a nuclear power plant is used to drive the primary coolant circuit. In Generation III nuclear power technology (AP / CAP reactors), canned motor pumps are widely used. In a canned motor pump, the motor and impeller are coaxial and suspended and welded to the pump casing of the lower head of the steam generator. The motor and impeller together constitute a removable component. The canned motor pump is designed for 60 years of maintenance-free operation; however, in actual operation, multiple factors such as the intrusion of foreign objects, internal component failure, and improper assembly can lead to unexpected damage to the main pump motor during service, requiring replacement of the removable component.

[0003] The removable assembly's connection to the pump housing consists of two parts: the main bolts between the pump housing flange and the motor main flange, and the upper C-ring welded between the pump housing flange and the motor upper end cap. This C-ring is also known as a Canopy sealing ring. Therefore, to remove and replace the removable assembly, in addition to removing the main bolts, it is necessary to cut the upper C-ring and grind away any remaining C-ring residue on the pump housing flange.

[0004] Currently, replacing removable components requires two high-precision operations: first, cutting the upper C-ring to remove the component, and then machining the remaining ring suspended above the pump casing flange. Due to the extremely limited working space and the need for extremely high precision, specialized tools are essential. The machining device is particularly complex—in the suspended state, the machining device requires not only extremely stable support but also precise control of the axial movement of the cutting tool while it makes circumferential feed along the pump casing flange to dynamically adjust the cutting depth. These complex functional requirements result in a cumbersome equipment design, leading to high manufacturing and procurement costs. Furthermore, the large size of the equipment causes storage difficulties and increases the learning and operational challenges for maintenance personnel. Utility Model Content

[0005] The purpose of this invention is to provide a cutting and cleaning device for the upper C-ring of the shielded main pump in a nuclear power plant, so as to solve the problems of high manufacturing and procurement costs and storage difficulties caused by the existing two-piece cutting and cleaning device for the C-ring.

[0006] To achieve the above objectives, this utility model provides a C-ring cutting and root cleaning device for the upper part of a shielded main pump in a nuclear power plant, comprising: a trolley system, a carriage system, a motor system, and a cutting tool system; The trolley system includes a trolley base, a base plate, a trolley travel drive mechanism, and a track guide mechanism; Both the trolley travel drive mechanism and the track guide mechanism are located below the trolley base. The trolley travel drive mechanism is fixedly installed on the base plate, and the track guide mechanism is symmetrically installed on the bottom of the base plate. The track guide mechanism engages with the external track laid on the upper end face of the pump casing flange and is clamped on the external track. The trolley system includes a trolley base and a radial feed mechanism; The trolley base is disposed on the upper surface of the base plate, and the radial feed mechanism is installed at the edge of the trolley base. The radial feed mechanism is configured to drive the trolley system to move radially along the upper end face of the pump housing flange. The motor system includes a main spindle motor, which is vertically fixed to the upper surface of the trolley base, and the output shaft of the main spindle motor passes vertically upward through the trolley base; The cutting tool system is located above the trolley base. The trolley base includes a cutting tool and a cutting tool holder. The lower end of the cutting tool holder is connected to the vertically upward output shaft of the main spindle motor through a motor bearing housing. The upper end of the cutting tool holder is connected to the cutting tool. The cutting tool's disc plane is parallel to the upper end face of the pump housing flange.

[0007] In one feasible implementation, the trolley travel drive mechanism includes a trolley travel motor and a trolley travel gear; The trolley travel motor is fixed on the trolley base, and the output end of the trolley travel motor is connected to the gear shaft of the trolley travel gear. The trolley traveling gear is fixed to the lower surface of the base plate, and the trolley traveling gear meshes with the arc-shaped rack on the external track.

[0008] In one feasible implementation, the track guiding mechanism includes an inner guide wheel group and an outer guide wheel group, wherein the inner guide wheel group and the outer guide wheel group are arranged opposite to each other on a horizontal plane; The inner guide wheel assembly is installed on the lower surface of the base plate near the inner side. The inner guide wheel assembly includes an inner rail guide wheel and an inner rail guide wheel adjusting nut. The inner rail guide wheel is used to contact the inner side of the outer rail. The inner track guide wheel adjusting nut is threadedly engaged with the wheel axle of the inner track guide wheel. The inner track guide wheel adjusting nut drives the wheel axle of the inner track guide wheel to move along the axial direction by rotation, thereby driving the inner track guide wheel to move inward or outward. The outer guide wheel assembly is installed on the lower surface of the base plate near the outer side, and the outer guide wheel assembly includes an outer rail guide wheel and an outer rail guide wheel adjusting nut; The outer track guide wheel is used to contact the outer side of the outer track; The adjusting nut of the outer track guide wheel is threadedly engaged with the wheel axle of the outer track guide wheel. The adjusting nut of the outer track guide wheel drives the wheel axle of the outer track guide wheel to move along the axial direction by rotating, so as to drive the outer track guide wheel to move inward or outward.

[0009] In one feasible implementation, the radial feed mechanism includes a trolley radial travel support plate, a trolley radial travel screw, a handle plug, and a trolley travel handle; The radial travel support plate of the trolley is fixed to the upper surface of the trolley base; The radial travel screw of the trolley is arranged along the longitudinal direction of the trolley base. The rear end of the radial travel screw is connected to the radial travel support plate of the trolley through a bearing seat. The middle part of the radial travel screw is engaged with a threaded hole provided on the trolley base. The handle plug is fixed to one end of the radial travel screw of the trolley near the outside of the device, and the trolley travel handle is detachably inserted into the handle plug.

[0010] In one feasible implementation, the motor system further includes a trolley radial limiting component; The trolley radial limiting assembly includes a trolley radial limiting plate and a trolley radial limiting bolt assembly; The trolley radial limiting plate is vertically fixed to the upper edge of the base plate; The trolley radial limiting bolt assembly extends horizontally through the upper part of the trolley radial limiting plate, and the front end of the trolley radial limiting bolt assembly is pressed against the side wall of the trolley base.

[0011] In one feasible implementation, the motor system further includes a support structure, which includes: a vertical support for the main spindle motor, a first inclined support for the main spindle motor, and a second inclined support for the main spindle motor. The bottom of the main spindle motor vertical support is fixed to the trolley base, and the main spindle motor vertical support is provided with a mounting part, which is fixedly connected to the main spindle motor housing. The first and second inclined supports of the main spindle motor are symmetrically arranged on both sides of the main spindle motor, with one end connected to the housing of the main spindle motor and the other end connected to the vertical support of the main spindle motor or the trolley base.

[0012] In one feasible implementation, the mounting portion includes an annular adjustment groove extending in a vertical direction and a fastening bolt; The annular adjustment grooves are arranged on the left and right sides of the central axis of the spindle motor, and there are at least two annular adjustment grooves. The fastening bolts pass through the annular adjustment groove and are threadedly connected to the spindle motor housing.

[0013] In one feasible implementation, the vehicle system further includes a bottom support assembly; The bottom support assembly includes a trolley bottom support screw and a trolley bottom support sleeve; The bottom support sleeve of the trolley is fixed to the bottom of the trolley base; The upper part of the bottom support screw of the trolley is threadedly engaged with the bottom support sleeve of the trolley, and the lower end of the bottom support screw of the trolley rests on the base of the trolley.

[0014] In one feasible implementation, the base plate is a ring frame structure, and the base plate is provided with multiple weight-reducing holes.

[0015] In one feasible implementation, the cutting tool is one of a face milling cutter, a cutting disc, and a saw blade.

[0016] This application provides a C-ring cutting and cleaning device for the upper part of a shielded main pump in a nuclear power plant. This simplifies the process of cutting and cleaning the upper C-ring of the shielded main pump. Instead of the common practice in the nuclear power industry of cutting first and then cleaning, this device utilizes the inherent characteristic of a face milling cutter that does not damage the contact surface, achieving simultaneous cutting and cleaning, significantly simplifying on-site operations. This invention eliminates the need for cleaning after removing removable components, saving manpower and reducing radiation exposure for workers. Furthermore, this invention proposes a novel integrated C-ring cutting and cleaning device, reducing equipment procurement costs. The simplified structure also reduces the need for large storage space and facilitates operation by maintenance and repair personnel. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the embodiments of the present invention. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] Figure 1 This is a schematic diagram of the structure of the upper C-ring cutting and root cleaning device of the shielded main pump of a nuclear power plant, as shown in an exemplary embodiment of this application; Figure 2 This is a schematic diagram of the bottom structure of a vehicle system shown in an exemplary embodiment of this application.

[0019] Attached image annotations: 1-Cutting tool; 2-Cutting tool fixture; 3-Motor bearing housing; 4-Carriage base; 5-Vertical support; 6-Carriage travel motor; 7-Inner rail guide wheel adjusting nut; 8-Inner rail guide wheel; 9-Carriage travel gear; 10-Outer rail guide wheel; 11-Outer rail guide wheel adjusting nut; 12-Carriage radial limit plate; 13-Carriage radial limit bolt assembly; 14-Carriage radial travel support plate; 15-Carriage radial travel screw; 16-Handle plug; 17-Carriage travel handle; 18-Annular adjusting groove; 19-Fasting bolt; 20-Base plate; 21-Diagonal support one; 22-Spindle motor; 23-Carriage base; 24-Carriage bottom support screw; 25-Carriage bottom support sleeve; 26-Diagonal support two. Detailed Implementation

[0020] Example implementations will now be described more fully with reference to the accompanying drawings. However, example implementations can be implemented in many forms and should not be construed as limited to the examples set forth herein.

[0021] Conversely, these implementations are provided to make the embodiments of this application more comprehensive and complete, and to fully convey the concept of exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more implementations. In the following description, numerous specific details are provided to give a thorough understanding of the implementation of the embodiments of this application.

[0022] In third-generation AP / CAP reactor nuclear power plants, canned motor pumps are widely used as the main coolant pumps. The motor and impeller are coaxial, forming a removable assembly, which is suspended and welded to the lower head of the steam generator. Although this assembly is designed for 60 years of maintenance-free operation, it may be damaged and require replacement due to foreign object intrusion, component failure, or assembly problems. Replacement requires removing the main bolts and cutting the upper C-ring (also known as the Canopy sealing ring) welded between the pump casing flange and the upper head of the motor. The remaining C-ring residue on the flange is then machined to remove the root. The current replacement process involves two high-precision steps, requiring specialized tooling due to the extremely limited working space. The root-cleaning device is particularly complex, requiring stable support for the cutting tool in an inverted position while simultaneously achieving precise control of circumferential feed and axial depth. This results in a cumbersome structure, high manufacturing cost, and large size, making storage inconvenient and increasing the difficulty of operation and training for maintenance personnel.

[0023] To solve the above problems, refer to Figure 1 and Figure 2 As shown in the figure, this application embodiment provides a C-ring cutting and root cleaning device for the upper part of the shielded main pump of a nuclear power plant, including: a trolley system, a carriage system, a motor system and a cutting tool system.

[0024] The trolley system includes a trolley base 4, a base plate 20, a trolley travel drive mechanism, and a track guide mechanism. The trolley base 4 is located at the bottom of the device, and the base plate 20 is fixed above the trolley base 4, forming a frame structure. The trolley travel drive mechanism is mounted on the upper surface of the base plate 20, and the track guide mechanism is symmetrically arranged at the bottom of the base plate 20. Its inner track guide wheel set and outer guide wheel set respectively clamp the inner and outer sides of the outer track. The trolley system engages with the outer track through the track guide mechanism, enabling the device to move circumferentially along the pump casing flange.

[0025] The carriage system includes a carriage base 23 and a radial feed mechanism. The carriage base 23 is located on the upper surface of the base plate 20, and the radial feed mechanism is installed at the edge of the carriage base 23. Radial drive is achieved through the carriage radial travel screw 15 and the carriage travel handle 17. The carriage system adjusts the axial position of the tool 1 and controls the cutting depth through the radial feed mechanism.

[0026] The motor system includes a spindle motor 22, which is vertically fixed to the upper surface of the carriage base 23, with its output shaft passing vertically upward through a through hole in the base plate 20. The motor system provides stable support for the spindle motor 22 to ensure the axial stability of the tool 1 during rotation.

[0027] The cutting tool system is mounted above the trolley base 4 and includes a cutting tool 1 and a cutting tool holder 2. The cutting tool 1 is connected to the output shaft of the main spindle motor 22 via the motor bearing housing 3 through the cutting tool holder 2. The upper end of the cutting tool holder 2 clamps the cutting tool 1, ensuring that the cutting disc plane is parallel to the upper end face of the pump casing flange. The cutting tool system is used to directly perform cutting and cleaning operations, completing the cutting of the C-ring and the cleaning of residual rings through the rotation of the cutting tool 1.

[0028] During operation, the trolley travel motor 6 of the trolley travel drive mechanism starts, driving the trolley travel gear 9 to rotate. The gear meshes with the arc-shaped rack of the external track, driving the trolley base 4 to move circumferentially along the track. The trolley travel handle 17 of the trolley system is inserted into the handle plug 16, and the rotating screw pushes the trolley base 23 to slide radially along the base plate 20, adjusting the axial distance between the cutter 1 and the pump housing flange. After the spindle motor 22 starts, the output shaft drives the cutter 1 to rotate at high speed through the cutter clamp 2, completing the cutting and root cleaning actions.

[0029] This embodiment integrates cutting and cleaning functions through a unified design. Utilizing the rotational characteristics of the face milling cutter 1, it simultaneously achieves C-ring cutting and residual ring cleaning, avoiding the high precision requirements and complex transmission mechanisms of traditional step-by-step operations. The coordinated movement of the large and small carriages enables precise control in both circumferential and radial dimensions, solving the operational difficulties caused by limited working space. This solution simplifies the process flow, reduces the number of equipment and operating steps, lowers the complexity of the transmission mechanism, and reduces equipment size, facilitating storage and transportation. The modular design of the entire device reduces maintenance costs and improves maintenance efficiency.

[0030] In some embodiments of this application, the trolley travel drive mechanism includes a trolley travel motor 6 and a trolley travel gear 9. The trolley travel motor 6 is fixed to the upper surface of the trolley base 23, and its output shaft is connected to the gear shaft of the trolley travel gear 9. The trolley travel gear 9 is mounted on the lower surface of the base plate 20, and its outer edge meshes with the arc-shaped rack of the external track to achieve power transmission.

[0031] Among them, the trolley travel motor 6 provides rotational power and drives the trolley system to move circumferentially along the external track through gear transmission; the trolley travel gear 9 serves as the transmission medium, converting the motor power into linear motion in the track direction, ensuring movement accuracy and stability.

[0032] Specifically, when the circumferential position of the device needs to be adjusted, the trolley travel motor 6 starts, and the output shaft drives the trolley travel gear 9 to rotate. The gear meshes with the external track arc rack, and the rotational motion is converted into the linear movement of the trolley base 4 through gear and rack transmission, thereby realizing the circumferential positioning of the device on the upper end face of the pump casing flange.

[0033] This embodiment uses a rack and pinion drive instead of a traditional chain or belt drive, further improving transmission efficiency and positioning accuracy, and reducing errors caused by transmission backlash. The direct connection between the trolley travel motor 6 and the trolley travel gear 9 reduces energy loss and enhances the reliability of power transmission.

[0034] In some embodiments of this application, the track guiding mechanism includes an inner guide wheel assembly and an outer guide wheel assembly, and the inner guide wheel assembly and the outer guide wheel assembly are arranged opposite each other on a horizontal plane.

[0035] The inner guide wheel assembly consists of an inner rail guide wheel 8 and an inner rail guide wheel adjusting nut 7, and is installed on the inner side of the lower surface of the base plate 20. The outer guide wheel assembly consists of an outer rail guide wheel 10 and an outer rail guide wheel adjusting nut 11, and is installed on the outer side of the lower surface of the base plate 20. The inner rail guide wheel 8 and the outer rail guide wheel 10 respectively contact the inner and outer sides of the outer rail, and the axial movement of the wheel axle is achieved by adjusting the nuts.

[0036] Specifically, the adjusting nut 11 of the outer track guide wheel is threadedly engaged with the axle of the outer track guide wheel 10. The adjusting nut 11, through rotation, drives the axle of the outer track guide wheel 10 to move along the axial direction, thereby causing the outer track guide wheel 10 to move inward or outward. It can be understood that the inner and outer guide wheel sets together clamp the outer track, preventing the trolley system from shifting during movement. The adjusting nut, through its threaded engagement, allows for fine-tuning of the guide wheel position and can also adapt to installation requirements with different track spacings, ensuring tight contact between the inner track guide wheel 8, the outer track guide wheel 10, and the outer track.

[0037] During installation, the axle positions of the inner track guide wheel 8 and the outer track guide wheel 10 are adjusted by rotating the inner track guide wheel adjusting nut 7 and the outer track guide wheel adjusting nut 11, ensuring a tight fit between the guide wheels and the inner / outer side of the outer track. During movement, the guide wheels roll along the track surface, reducing frictional resistance through the axle bearings and ensuring smooth movement of the trolley system.

[0038] In this embodiment, the symmetrically arranged inner and outer guide wheel sets eliminate track gaps through bidirectional clamping force, improving movement stability and enhancing the stability of the trolley system in confined spaces, while reducing vibration and noise. The threaded adjustment function of the inner track guide wheel adjusting nut 7 and the outer track guide wheel adjusting nut 11 allows for the calibration of the positions of the inner track guide wheel 8 and the outer track guide wheel 10, adapting to different track installation errors and track sizes, thus improving equipment versatility.

[0039] In some embodiments of this application, the radial feed mechanism includes a trolley radial travel support plate 14, a trolley radial travel screw 15, a handle plug 16, and a trolley travel handle 17. The trolley radial travel support plate 14 is fixed to the upper surface of the trolley base 23. The trolley radial travel screw 15 is arranged longitudinally along the trolley base 23, and its rear end is connected to the trolley radial travel support plate 14 through a bearing seat. Its middle part mates with a threaded hole in the trolley base 23. The handle plug 16 is fixed to the outer end of the screw, and the trolley travel handle 17 is detachably inserted into the handle plug 16.

[0040] When adjusting the axial position of the tool 1, the operator inserts the carriage travel handle 17 into the handle plug 16 and rotates the handle clockwise / counterclockwise to drive the carriage radial travel screw 15 to rotate. The screw, through threaded engagement, pushes the carriage base 23 to slide radially along the surface of the base plate 20, thereby adjusting the axial distance between the tool 1 and the pump housing flange. The carriage radial travel screw 15 converts the rotational motion of the handle into the radial sliding motion of the carriage base 23 through threaded transmission, achieving precise adjustment of the axial position of the tool 1. The insertion design of the handle plug 16 and the carriage travel handle 17 facilitates manual operation by the operator and adapts to the operational needs of confined spaces.

[0041] In some embodiments of this application, the motor system further includes a trolley radial limiting assembly, which includes a trolley radial limiting plate 12 and a trolley radial limiting bolt assembly 13. The trolley radial limiting plate 12 is vertically fixed to the edge of the upper surface of the base plate 20, and the trolley radial limiting bolt assembly 13 horizontally penetrates the upper part of the trolley radial limiting plate 12, with its front end pressing against the side wall of the trolley base 23.

[0042] Understandably, the radial limiting plate 12 of the trolley provides a physical barrier to prevent the trolley base 23 from exceeding the safe range during radial movement. The radial limiting bolt assembly 13 of the trolley achieves precise control of the tightening force through thread adjustment, ensuring that the trolley base 23 remains in a fixed position after moving into place, avoiding displacement deviation during the cutting process.

[0043] Specifically, after the carriage base 23 moves radially to the target position, the operator rotates the carriage radial limit bolt assembly 13, causing the front end of the bolt to press against the side wall of the carriage base 23. The tightening force of the bolt fixes the position of the carriage, preventing accidental movement during the rotation and cutting of the cutter 1.

[0044] In some embodiments of this application, the motor system further includes a support structure, which comprises a main spindle motor vertical support 5, a main spindle motor inclined support 21, and a main spindle motor inclined support 26. The bottom of the main spindle motor vertical support 5 is fixed to the trolley base 23, and a mounting part is provided thereon, which is fixedly connected to the housing of the main spindle motor 22. The main spindle motor vertical support 5 is used to provide the main support force in the vertical direction to ensure the vertical stability of the output shaft of the main spindle motor 22.

[0045] Diagonal supports 21 and 26 are symmetrically arranged on both sides of the main spindle motor 22, with one end connected to the housing of the main spindle motor 22 and the other end connected to the vertical support 5 or the trolley base 23. Diagonal supports 21 and 26 enhance the vibration resistance of the motor system by providing diagonal support, reducing vibration and displacement during rotation.

[0046] In some embodiments of this application, the mounting part includes an annular adjustment groove 18 and fastening bolts 19. The annular adjustment groove 18 is symmetrically arranged on the top of the vertical support 5 along the central axis of the spindle motor 22, and the groove body is an arc-shaped elongated hole. The fastening bolts 19 pass through the adjustment groove and cooperate with the threaded holes of the spindle motor 22 housing to realize the fixing and adjustment of the motor position.

[0047] In this embodiment, the arc-shaped design of the annular adjustment groove 18 adapts to the adjustment requirements of different installation angles, solves the problem of axial misalignment caused by manufacturing or installation errors, improves the installation accuracy of the equipment, reduces cutting errors caused by axial misalignment, and enhances the adaptability of the equipment to different working conditions. The bolt locking function further ensures that the adjusted position remains stable during operation.

[0048] In some embodiments of this application, the bottom support assembly includes a trolley bottom support screw 24 and a trolley bottom support sleeve 25. The trolley bottom support sleeve 25 is fixed to the bottom of the trolley base 23, and its inner wall is threaded; the upper part of the trolley bottom support screw 24 is threaded with the inner wall of the sleeve, and the lower end is pressed against the upper surface of the trolley base 23.

[0049] The bottom support sleeve 25 of the trolley bears the weight and operating load of the trolley base 23 through a threaded connection, preventing structural deformation in the inverted state. The bottom support screw 24 of the trolley achieves precise control of the support force through thread adjustment to adapt to different load requirements.

[0050] Specifically, when the trolley system is in an inverted state, the bottom support screw 24 of the trolley rotates downwards to press against the trolley base 23, providing additional support force to prevent the trolley base 23 from bending or displacing under the action of gravity. The magnitude of the support force can be adjusted by adjusting the screw depth of the bottom support screw 24 of the trolley.

[0051] In some embodiments of this application, the base plate 20 is an annular frame structure with multiple weight-reducing holes evenly distributed along the circumference of the base plate. The base plate 20 is fixed to the upper part of the trolley base 4 by bolts, forming the base structure of the device.

[0052] Understandably, the ring-shaped frame structure of the base plate 20, while ensuring structural strength, reduces the overall weight through weight-reducing holes, facilitating equipment handling and installation, and also making it easier for operators or hoisting equipment to move the equipment. During operation, the ring-shaped frame structure bears the loads of the trolley system and the auxiliary trolley system through evenly distributed stress paths.

[0053] In some embodiments of this application, the cutting tool 1 is one of a face milling cutter, a cutting blade, and a saw blade.

[0054] Among them, the face milling cutter adopts a multi-tooth design, and the structure is divided into integral, insert tooth, and indexable types. It has a large diameter and high rigidity, making it suitable for machining hard skin and hardened workpieces. The cutting blade is divided into resin and diamond types. The thin design reduces cutting resistance and requires cooling to extend its service life. The saw blade is made of cemented carbide and high-speed steel, with various tooth shapes. The number of teeth affects the cutting speed and surface quality. The ultra-thin design reduces waste, and the performance is optimized by combining silencer holes and scraper technology.

[0055] Face milling cutters are suitable for milling stepped surfaces and large flat surfaces on milling machines. Coarse teeth are used for large machining allowances, while fine teeth are used for thin-walled parts or precision machining of cast iron. Cutting discs are compatible with fixed or mobile cutting machines. Resin discs are used for metal cutting, while diamond discs are used for stone or ceramics. For low-power equipment, thin discs are selected to improve sharpness. Saw blades cover the processing of wood, metal, and special materials and are compatible with table saws, sliding table saws, and other equipment. The tooth shape and number of teeth need to be optimized according to the working conditions, such as low-tooth high-speed roughing and high-tooth fine saw blades for precision machining.

[0056] In practical use, replacing the tool type 1 can improve the equipment's adaptability to different cutting conditions and reduce cutting failures caused by improper tool selection. Furthermore, the quick tool change function reduces operation time and improves overall work efficiency.

[0057] The C-ring cutting and cleaning device for the upper part of the shielded main pump in nuclear power plants provided in this application achieves the cutting and cleaning of the upper C-ring of the shielded main pump through the coordinated operation of the trolley system, the auxiliary trolley system, the motor system, and the cutting tool system. In use, the device is first installed on the external rail on the upper end face of the pump casing flange via a track guide mechanism. The circumferential position is adjusted by the trolley travel drive mechanism, the radial feed mechanism of the auxiliary trolley controls the axial depth of the cutting tool, and the spindle motor drives the cutting tool to rotate to complete the cutting and cleaning. The support structure and limiting components ensure stability and accuracy during operation, the bottom support component adapts to the operation requirements in an inverted state, and the ring frame base plate reduces the weight of the equipment for easy handling.

[0058] This device simplifies the process flow, reduces the number of equipment and operating steps, and further minimizes the equipment's size, facilitating storage and transportation in confined spaces. Modular design reduces maintenance costs and improves repair efficiency. High-precision positioning and stable support enhance cutting quality and operational safety. Furthermore, the device's versatility is enhanced by allowing selection of different cutting tool types to meet various cutting needs. The C-ring cutting and cleaning device for the upper part of the main shielded pump in nuclear power plants, through structural optimization and functional integration, effectively solves the problems of complex operation, low precision, and difficult maintenance in traditional C-ring replacement processes, improving the efficiency and safety of nuclear power plant operation and maintenance.

[0059] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the disclosure in the specification and the embodiments. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. A C-ring cutting and root cleaning device for the upper part of a shielded main pump in a nuclear power plant, characterized in that, include: The main carriage system, the auxiliary carriage system, the motor system, and the tooling system; The trolley system includes a trolley base (4), a base plate (20), a trolley travel drive mechanism, and a track guide mechanism; The trolley travel drive mechanism and the track guide mechanism are both located below the trolley base (4); The trolley travel drive mechanism is fixedly installed on the base plate (20), and the track guide mechanism is symmetrically installed on the bottom of the base plate (20). The track guide mechanism meshes with the external track laid on the upper end face of the pump casing flange and is clamped on the external track. The trolley system includes a trolley base (23) and a radial feed mechanism; The trolley base (23) is disposed on the upper surface of the base plate (20), and the radial feed mechanism is installed at the edge of the trolley base (23). The radial feed mechanism is configured to drive the trolley system to move radially along the upper end face of the pump housing flange. The motor system includes a spindle motor (22), which is vertically fixed to the upper surface of the trolley base (23), and the output shaft of the spindle motor (22) passes vertically upward through the trolley base (4). The cutting tool system is located above the trolley base (4). The trolley base (4) includes a cutting tool (1) and a cutting tool holder (2). The lower end of the cutting tool holder (2) is connected to the vertically upward output shaft of the main spindle motor (22) through the motor bearing housing (3). The upper end of the cutting tool holder (2) is connected to the cutting tool (1). The cutting disc plane of the cutting tool (1) is parallel to the upper end face of the pump housing flange.

2. The C-ring cutting and root cleaning device for the upper part of the shielded main pump of a nuclear power plant according to claim 1, characterized in that, The trolley travel drive mechanism includes a trolley travel motor (6) and a trolley travel gear (9). The trolley travel motor (6) is fixed on the trolley base (23), and the output end of the trolley travel motor (6) is connected to the gear shaft of the trolley travel gear (9); The trolley traveling gear (9) is fixed to the lower surface of the base plate (20), and the trolley traveling gear (9) meshes with the arc-shaped rack on the external track.

3. The C-ring cutting and root cleaning device for the upper part of the shielded main pump in a nuclear power plant according to claim 1, characterized in that, The track guiding mechanism includes an inner guide wheel group and an outer guide wheel group, which are arranged opposite to each other on a horizontal plane. The inner guide wheel assembly is installed on the lower surface of the base plate (20) near the inner side. The inner guide wheel assembly includes an inner rail guide wheel (8) and an inner rail guide wheel adjusting nut (7). The inner rail guide wheel (8) is used to contact the inner side of the outer rail. The inner track guide wheel adjusting nut (7) is threadedly engaged with the wheel axle of the inner track guide wheel (8). The inner track guide wheel adjusting nut (7) drives the wheel axle of the inner track guide wheel (8) to move along the axial direction by rotating, so as to drive the inner track guide wheel (8) to move inward or outward. The outer guide wheel assembly is installed on the lower surface of the base plate (20) near the outer side. The outer guide wheel assembly includes an outer track guide wheel (10) and an outer track guide wheel adjusting nut (11). The outer track guide wheel (10) is used to contact the outer side of the outer track; The outer track guide wheel adjusting nut (11) is threadedly engaged with the wheel axle of the outer track guide wheel (10). The outer track guide wheel adjusting nut (11) drives the wheel axle of the outer track guide wheel (10) to move along the axial direction by rotating, so as to drive the outer track guide wheel (10) to move inward or outward.

4. The C-ring cutting and root cleaning device for the upper part of the shielded main pump in a nuclear power plant according to claim 1, characterized in that, The radial feed mechanism includes a trolley radial travel support plate (14), a trolley radial travel screw (15), a handle plug (16), and a trolley travel handle (17). The radial travel support plate (14) of the trolley is fixed to the upper surface of the trolley base (23); The radial travel screw (15) of the trolley is arranged along the longitudinal direction of the trolley base (23). The rear end of the radial travel screw (15) is connected to the radial travel support plate (14) of the trolley through a bearing seat. The middle part of the radial travel screw (15) is engaged with the threaded hole provided on the trolley base (23). The handle plug (16) is fixed to one end of the radial travel screw (15) of the trolley near the outside of the device, and the trolley travel handle (17) is detachably inserted into the handle plug (16).

5. The C-ring cutting and root cleaning device for the upper part of the shielded main pump in a nuclear power plant according to claim 1, characterized in that, The motor system also includes a trolley radial limiting component; The trolley radial limiting assembly includes a trolley radial limiting plate (12) and a trolley radial limiting bolt assembly (13). The radial limiting plate (12) of the trolley is vertically fixed to the edge of the upper surface of the base plate (20); The trolley radial limiting bolt assembly (13) extends horizontally through the upper part of the trolley radial limiting plate (12), and the front end of the trolley radial limiting bolt assembly (13) is pressed against the side wall of the trolley base (23).

6. The C-ring cutting and root cleaning device for the upper part of the shielded main pump in a nuclear power plant according to claim 1, characterized in that, The motor system also includes a support structure, which includes: a main spindle motor vertical support (5), a main spindle motor inclined support one (21), and a main spindle motor inclined support two (26). The bottom of the main spindle motor support (5) is fixed to the trolley base (23). The main spindle motor support (5) is provided with an installation part, which is fixedly connected to the housing of the main spindle motor (22). The first spindle motor inclined support (21) and the second spindle motor inclined support (26) are symmetrically arranged on both sides of the spindle motor (22), with one end connected to the housing of the spindle motor (22) and the other end connected to the spindle motor vertical support (5) or the trolley base (23).

7. The C-ring cutting and root cleaning device for the upper part of the shielded main pump of a nuclear power plant according to claim 6, characterized in that, The mounting part includes an annular adjustment groove (18) extending in the vertical direction and a fastening bolt (19). The annular adjustment groove (18) is provided on the left and right sides of the central axis of the main spindle motor (22), and there are at least two annular adjustment grooves (18); The fastening bolt (19) passes through the annular adjustment groove (18) and is threadedly connected to the housing of the main spindle motor (22).

8. The C-ring cutting and root cleaning device for the upper part of the shielded main pump of a nuclear power plant according to claim 1, characterized in that, The vehicle system also includes a bottom support assembly; The bottom support assembly includes a bottom support screw (24) for the trolley and a bottom support sleeve (25) for the trolley. The bottom support sleeve (25) of the trolley is fixed to the bottom of the trolley base (23); The upper part of the bottom support screw (24) of the trolley is threadedly engaged with the bottom support sleeve (25) of the trolley, and the lower end of the bottom support screw (24) of the trolley rests on the trolley base (23).

9. The C-ring cutting and root cleaning device for the upper part of the shielded main pump of a nuclear power plant according to any one of claims 1 to 8, characterized in that, The base plate (20) is a ring frame structure, and the base plate (20) is provided with multiple weight reduction holes.

10. The C-ring cutting and root cleaning device for the upper part of the shielded main pump of a nuclear power plant according to any one of claims 1 to 8, characterized in that, The cutting tool (1) is one of a face milling cutter, a cutting blade, and a saw blade.

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