Fuel assembly gripper with self-locking by mounting fuel

Abstract

The application discloses a fuel assembly grabber with self-locking function by mounting fuel, and relates to the technical field of nuclear reactor engineering. The grabber comprises a grabber assembly, a driving assembly, a connecting assembly, a suspension assembly and a gas circuit assembly. The driving assembly is connected above the grabber assembly, the suspension assembly is connected above the driving assembly through the connecting assembly, and the gas circuit assembly is connected with the driving assembly and supplies high-pressure gas to the driving assembly. The grabber assembly is provided with a load-bearing self-locking structure and a conical guide structure. The connecting assembly is a flexible connecting assembly, and provides the grabber assembly with a radial deflection freedom. The grabber can automatically maintain locking by gravity when the fuel is mounted, and no external power is needed for continuous energy supply. Meanwhile, through cooperation of the conical guide and the flexible connection, large-tolerance self-adaptive centering is realized, and the safety, fault tolerance and convenience of deep underwater fuel operation are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of nuclear reactor engineering technology, and in particular to a fuel assembly gripper that achieves self-locking by attaching fuel. Background Technology

[0002] A pressurized water reactor nuclear power plant's reactor core contains hundreds of fuel assemblies, each consisting of a bundle of fuel rods and a rectangular structure with a square cross-section. The loading and unloading of fuel assemblies into or out of the core, as well as their removal from the reactor to the spent fuel pool, are all accomplished using refueling machines or fuel handling tools. The fuel gripper, as the claw component of the refueling machine or fuel handling tool, is the key actuator that directly contacts and grasps and releases the fuel assembly being handled.

[0003] Existing fuel grabbers have the following technical drawbacks: First, although they are equipped with a self-locking mechanism to prevent accidental detachment of fuel assemblies, misoperation of the slider can still cause the grabber to unlock, leading to fuel assembly detachment and a fall accident. Second, existing grabbers rely on the insertion of a positioning pin at the bottom into a pin hole at the top of the fuel assembly for guidance and positioning, which is difficult to align in refueling water depths of approximately 10–20 meters. The development of integrated reactors further increases the container height and operating depth, making positioning even more challenging.

[0004] Existing patent CN214653021U uses a slider to push and pull four hooks. Pushing down the slider causes the hooks to rotate outwards and engage with the lifting beam, and the slider abuts against the hook arm to achieve self-locking. Existing patent CN102415012A has a similar principle, but uses an electromagnet and spring to drive the slider to reset. However, neither of these solutions solves the risk of unlocking due to misoperation, nor does it improve the guidance and positioning challenges in deep-water environments.

[0005] In summary, there is an urgent need for a fuel gripper structure that can effectively prevent accidental unlocking of the slider and improve the convenience of deep-water positioning. Summary of the Invention

[0006] To address the risks of pressure loss and disengagement caused by fuel grippers relying on continuous external power for clamping in existing technologies, as well as insufficient tolerance and stringent positioning accuracy requirements during underwater alignment, this application proposes a fuel assembly gripper that achieves self-locking by loading fuel. This gripper can automatically maintain locking by gravity after being loaded with fuel, and its adaptive alignment through conical guides and flexible connections significantly improves the fault tolerance and convenience of long-distance underwater operations.

[0007] To achieve the above objectives, the first aspect of this application proposes a fuel assembly gripper that achieves self-locking by attaching fuel, the specific technical solution of which is as follows: A fuel assembly gripper that achieves self-locking by attaching fuel includes: Grab assembly for grabbing or releasing fuel assemblies; A drive component, connected above the gripper assembly, is used to provide driving force to the gripper assembly; A gas supply assembly for supplying high-pressure gas to the drive assembly; A suspension assembly, positioned above the drive assembly, is used for connection to external hoisting equipment; And a connecting component, connected between the suspension component and the drive component; The gripper assembly is equipped with a load-bearing self-locking structure, and the gripper assembly automatically maintains a locked state by the gravity of the fuel assembly when it is loaded with a fuel assembly.

[0008] Furthermore, the connecting component is a flexible connecting component, providing the gripper assembly with a radial yaw degree of freedom.

[0009] Furthermore, the gripper assembly includes a base and key claws and a reset structure mounted on the base. Multiple key claws are spaced apart circumferentially and are rotatably mounted on the base. The reset structure is installed inside the base and located below the key claws.

[0010] Furthermore, the key claw has an extended end and a driving end. The extended end extends out of the base for mounting with the fuel assembly, and the driving end is located inside the base for receiving driving force to drive the key claw to rotate.

[0011] Furthermore, the reset structure includes a support rod and a first elastic element sleeved outside the support rod. The support rod is located below the driving end of the key claw, and the first elastic element provides axial reset force to the driving end of the key claw through the support rod.

[0012] Furthermore, the gripper assembly also includes a key claw sleeve, which is fitted over the outside of the key claw. The key claw sleeve is provided with a wire rope connection part, which is used to drive the key claw to rotate and retract by pulling the wire rope from the outside in an emergency.

[0013] Furthermore, the lower end of the base is provided with a tapered guide structure, which is a tapered surface whose outer diameter gradually decreases from top to bottom at the lower end of the base.

[0014] Furthermore, the drive assembly includes a first cylinder and a second cylinder at least partially disposed inside the first cylinder. The lower end of the second cylinder extends out of the first cylinder and is connected to the gripper assembly. The second cylinder can slide axially relative to the first cylinder to drive the gripper assembly to perform gripping or releasing actions.

[0015] Furthermore, the drive assembly also includes a second elastic member, the two ends of which act on the first cylinder and the second cylinder respectively, for providing an axial restoring force to the second cylinder.

[0016] Furthermore, a top cover is provided at the upper end of the first cylinder, and a through hole is provided on the top cover for connecting the air passage assembly. High-pressure gas enters the interior of the first cylinder through the through hole, pushing the second cylinder to slide axially relative to the first cylinder.

[0017] Furthermore, the air circuit assembly includes an air tube and a sleeve coaxially sleeved outside it, with the lower end of the air tube connected to the drive assembly.

[0018] Furthermore, the suspension assembly includes a sleeve, the upper end of which has an axially penetrating through hole for the air passage assembly to pass through and extend out; the lower end of the sleeve has a plurality of circumferentially spaced extension arms, each of which is circumferentially limited and engaged with the upper end of the drive assembly.

[0019] Furthermore, a tension gauge is provided on the connecting component, and the tension gauge is connected to the lower end of the suspension component to detect the axial load of the gripper component.

[0020] Furthermore, it also includes an emergency unlocking mechanism, which includes a traction member, one end of which is connected to the gripper assembly, and the other end of which bypasses the drive assembly, passes through the suspension assembly, and extends upward.

[0021] To achieve the above objectives, a second aspect of this application provides a fuel assembly for use in conjunction with the aforementioned fuel assembly gripper. The top of the fuel assembly is provided with an inwardly protruding engagement flange, each of which is used for engaging and mounting with the gripper assembly.

[0022] By applying the above-described technical solution of the present invention, at least the following technical effects are achieved: 1. This invention incorporates a self-locking structure in the gripper assembly, enabling the gripper to automatically maintain a locked state by the weight of the fuel assembly after being loaded with fuel. Even if air pressure is accidentally introduced or an unlocking command is mistakenly issued, the air pressure is insufficient to overcome the weight of the fuel and retract the gripper. This structurally avoids the risk of the fuel assembly accidentally detaching and falling due to human error, air supply interruption, or electrical failure, thus achieving intrinsic safety protection.

[0023] 2. This invention provides a tapered guide structure that is wider at the top and narrower at the bottom at the lower end of the gripper assembly, and a flexible connecting component between the suspension assembly and the drive assembly. This allows the gripper to slide into the upper opening of the fuel assembly using the tapered surface even with large positional deviations. At the same time, the flexible connection provides radial yaw freedom, thereby achieving large-tolerance adaptive centering. This significantly reduces the dependence on positioning accuracy during long-distance underwater operations and improves positioning efficiency and fault tolerance.

[0024] 3. This invention provides two independent driving methods for the key claw, namely passive triggering and active driving, so that even when the spring force is too large and the key claw cannot rely on self-repositioning, the key claw can still be driven to rotate by the driving component to complete the operation. At the same time, a manual emergency unlocking mechanism is provided, so that the key claw can be manually retracted by a steel wire rope in case of pneumatic failure, so as to reliably disengage the gripper from the fuel assembly and avoid the risk of the gripper getting stuck in the fuel assembly and being unable to be pulled out.

[0025] 4. The present invention provides protruding limiting blocks on all four sides of the lower end of the outer cylinder, so that when the gripper descends to the preset end of the stroke, it abuts against the lifting beam of the fuel assembly, thereby limiting the gripper from descending too far, effectively preventing the lower end of the gripper from touching the fuel rod and causing damage, and ensuring the structural integrity of the fuel assembly.

[0026] 5. This invention sets multiple sets of force gauges on the connecting components to monitor the axial load changes on the load path of each key claw, enabling operators to determine in real time whether each key claw is in a normal gripping state and whether the fuel assembly has been reliably gripped. At the same time, during the hoisting process, abnormal working conditions such as jamming, friction or collision are identified through load fluctuations, thereby providing real-time load feedback and fault warning.

[0027] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0028] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the physical structure of a fuel assembly gripper that achieves self-locking by mounting fuel, as proposed in this invention, is shown; Figure 2 A three-dimensional structural schematic diagram of a fuel assembly gripper that achieves self-locking by mounting fuel, as proposed in this invention, is shown; Figure 3 A cross-sectional schematic diagram of a fuel assembly gripper that achieves self-locking by mounting fuel, as proposed in this invention, is shown. Figure 4A schematic diagram of the key claw of a fuel assembly gripper that achieves self-locking by loading fuel is shown in this invention. Figure 5 A schematic diagram of the key claw sleeve of a fuel assembly gripper that achieves self-locking by loading fuel is shown. Figure 6 A schematic diagram of the engagement of the key claw and key claw sleeve of a fuel assembly gripper that achieves self-locking by loading fuel is shown. Figure 7 A schematic diagram of the base of a fuel assembly gripper that achieves self-locking by mounting fuel, as proposed in this invention, is shown. Figure 8 A schematic diagram of the base of a fuel assembly gripper that achieves self-locking by mounting fuel, as proposed in this invention, is shown; Figure 9 A schematic diagram of the first cylinder of a fuel assembly gripper that achieves self-locking by loading fuel, as proposed in this invention, is shown; Figure 10 A schematic diagram of the second cylinder of a fuel assembly gripper that achieves self-locking by loading fuel, as proposed in this invention, is shown; Figure 11 A schematic diagram of the sleeve of a fuel assembly gripper that achieves self-locking by loading fuel is shown in the present invention; Figure 12 A schematic diagram of the sleeve of a fuel assembly gripper that achieves self-locking by loading fuel, as proposed in this invention, is shown.

[0029] Reference numerals: 10-Grip assembly, 11-Key claw, 111-First arm, 112-Second arm, 113-Key claw shaft hole, 114-Through hole, 12-Key claw sleeve, 121-Key claw sleeve shaft hole, 122-First connecting rod, 123-Second connecting rod, 124-Round hole, 13-Base, 131-First mounting hole, 132-Guide groove, 133-Second mounting hole, 14-Support rod, 15-First elastic element, 20-Drive assembly, 21-First cylinder, 211-Square flange, 212-Limit stop, 213-Lifting rod, 214 - Inclined hole, 22- Second cylinder body, 221- Annular groove, 23- Second elastic element, 24- Top cover, 25- Top cover end plate, 30- Air circuit assembly, 31- Air pipe, 32- Sleeve, 40- Suspension assembly, 41- Sleeve, 411- Columnar part, 412- Extension arm, 413- Through hole, 414- Circular groove, 415- Connecting hole, 416- Bolt hole, 417- Inclined through hole, 50- Connecting assembly, 51- Tension gauge, 52- Pull rod, 53- Connecting sleeve, 54- Chain, 55- Connecting seat, 60- Wire rope, 61- Fixing element. Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] The present invention will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed by the present invention.

[0032] To address the risks of depressurization and disengagement of existing fuel grabs and the insufficient underwater alignment tolerance, this application proposes a fuel assembly grab that achieves self-locking by attaching fuel. By integrating a load-bearing locking function with an adaptive guiding alignment structure, the risk of depressurization and disengagement is completely avoided, significantly improving the tolerance and operational efficiency of deep-water operations.

[0033] The following is in conjunction with the appendix Figures 1 to 11 This application provides a detailed description of an embodiment of a fuel assembly gripper that achieves self-locking by attaching fuel.

[0034] See Figure 1-2 As shown, this application proposes a fuel assembly gripper that achieves self-locking by mounting fuel, mainly comprising a gripper assembly 10, a drive assembly 20, an air passage assembly 30, a suspension assembly 40, and a connecting assembly 50. The drive assembly 20 is connected above the gripper assembly 10, and the drive assembly 20 is connected to the suspension assembly 40 via the connecting assembly 50. The air passage assembly 30 is connected to the drive assembly 20. The gripper assembly 10 is equipped with a load-bearing self-locking structure to achieve immediate locking upon mounting, allowing it to automatically maintain a gripping state without relying on external power when subjected to the weight of the fuel assembly. The connecting assembly 50 is a flexible connecting assembly to achieve autonomous centering and insertion while accommodating positioning deviations.

[0035] Specifically, the fuel assembly that cooperates with the fuel assembly gripper proposed in this invention has four inwardly protruding engagement flanges on the four edges of its top frame, which are fuel assembly lifting beams. Each engagement flange is used to engage and mount with the gripper assembly 10.

[0036] Specifically, in this embodiment, refer to Figure 3As shown, the gripper assembly 10 includes a key claw 11, a key claw sleeve 12, a base 13, a support rod 14, and a first elastic element 15. The upper end of the base 13 is connected to the lower end of the drive assembly 20. The key claw 11, key claw sleeve 12, support rod 14, and first elastic element 15 are all installed within the base 13. The key claw 11 and key claw sleeve 12 are rotatably mounted on the upper part of the base 13, with four sets correspondingly arranged around the base 13. The support rod 14 is located at the lower part of the base 13, with its upper end abutting against the key claw 11. The first elastic element 15 is sleeved on the support rod 14 and provides elastic support to the key claw 11 through the support rod 14. The key claw 11 has two driving methods. When the gripper assembly 10 descends, the key claw 11 abuts against the upper end of the fuel assembly. Under the continuous downward pressure of the gripper assembly 10's own weight, the key claw 11 is pushed back and rotates around the mounting point to avoid it. After the key claw 11 passes the upper opening of the fuel assembly, it is reset by rotating around its mounting fulcrum under the action of the first elastic element 15, thus locking the fuel assembly. When the elastic force of the first elastic element 15 is too large, causing the key claw 11 to be unable to rotate and insert into the fuel assembly, the driving end of the key claw 11 is driven downward by the driving assembly 20, causing the key claw 11 to rotate around its mounting fulcrum to avoid it.

[0037] Specifically, in this embodiment, refer to Figure 4 As shown, the key claw 11 is an integrally formed rod-shaped component. The key claw 11 has a first arm 111 and a second arm 112, which extend horizontally in opposite directions from the connection point and are staggered vertically. The first arm 111 is located above the second arm 112, and the connection point of the two arms overlaps to form a mounting part. The mounting part has a key claw shaft hole 113 for a mounting shaft to pass through. The free end of the first arm 111 extends out of the base 13 and can move axially up and down. The second arm 112 is located inside the base 13, and the driving component of the drive assembly 20 is located above it. In addition, a through hole 114 is provided on the first arm 111, and the through hole 114 penetrates the first arm 111 vertically.

[0038] Specifically, in this embodiment, refer to Figure 5-6As shown, the key claw sleeve 12 has a clamping structure and is sleeved on the mounting part of the key claw 11 and the outside of the first arm 111. Key claw sleeve shaft holes 121 are opened on both side plates corresponding to the mounting part for inserting a mounting shaft. A first connecting rod 122 and a second connecting rod 123 are located below the two side plates of the key claw sleeve 12. A round hole 124 is provided on the first connecting rod 122 below the first arm 111 for a steel wire rope passing through the through hole 114 on the first arm 111 to be wound and fixed. The second connecting rod 123 below the mounting part provides support and structural reinforcement. Under normal operating conditions, the key claw sleeve 12 does not rotate synchronously with the key claw 11. When the pneumatic driving force is insufficient to overcome the elastic force and jamming occurs, the key claw sleeve 12 is rotated around the mounting shaft by externally pulling the steel wire rope. The first connecting rod 122 near the free end of the first arm 111 pushes against the key claw 11, causing the key claw 11 to rotate and retract, achieving emergency unlocking and disengagement.

[0039] Specifically, in this embodiment, refer to Figure 7 As shown, the base 13 is a shell structure with a square upper end. First mounting holes 131 are provided around the top of the upper end for connection to the lower end of the drive assembly 20. Guide grooves 132 extending axially are respectively formed on the four side walls of the upper end of the base 13. The guide grooves 132 penetrate the side walls, allowing one end of the first arm 111 of the key claw 11 to extend out, and providing clearance and guiding constraint for the key claw 11 to rotate around the mounting shaft. Second mounting holes 133 corresponding to the shaft holes are provided on both sides of the guide grooves 132 for rotatably mounting the key claw 11 and key claw sleeve 12 to the base 13 via the mounting shaft.

[0040] Specifically, in this embodiment, refer to Figure 8 As shown, the lower end of the base 13 is a four-sided pyramid shape, with a stepped cavity extending axially inside. The stepped cavity accommodates the support rod 14 and provides the support rod 14 with space for vertical movement along the axial direction. At the same time, the stepped surface limits the downward axial movement of the support rod 14. By setting the lower end of the base 13 as a conical structure, the conical surface of the gripper assembly 10 can guide it into the upper opening of the fuel assembly during its descent. This effectively improves the alignment tolerance between the gripper assembly 10 and the fuel assembly, reduces the requirements for upstream positioning accuracy, and is particularly suitable for long-distance operation in deep-water environments.

[0041] Optionally, the inclination angle of the conical surface of the base 13 is 15° to 45°.

[0042] Specifically, in this embodiment, the support rod 14 is installed in the stepped cavity of the base 13, and includes an integrally formed upper plate and a lower rod. The top of the plate contacts the bottom of the second arm 112 of the key claw 11. The first elastic member 15 is sleeved on the outside of the rod, with its upper end abutting the lower end face of the plate and its lower end abutting the bottom wall of the stepped cavity of the base 13. The first elastic member 15 is in a pre-compressed state. When the key claw 11 rotates, the second arm 112 presses the support rod 14 downward, causing the support rod 14 to move downward along the axial direction and compress the first elastic member 15. After the external force is released, the first elastic member 15 pushes the support rod 14 upward to reset, thereby pushing the key claw 11 to reset.

[0043] Specifically, in this embodiment, refer to Figure 3 As shown, the drive assembly 20 includes a first cylinder 21, a second cylinder 22, a second elastic element 23, a top cover 24, a top cover end plate 25, and several sealing rings. The first cylinder 21 is coaxially sleeved on the outside of the second cylinder 22; the second elastic element 23 is installed in the axial space formed between the bottom of the first cylinder 21 and the bottom of the second cylinder 22 to provide a reset driving force; the top cover 24 is sealed at the upper end of the first cylinder 21; multiple sealing rings are provided between the top cover 24 and the first cylinder 21, and between the first cylinder 21 and the second cylinder 22, to ensure the internal sealing of the drive assembly 20.

[0044] Specifically, in this embodiment, refer to Figure 3 As shown, the first cylinder 21 has a hollow cylindrical structure with openings at both ends. Its inner wall surface has multiple stepped holes formed along the axial direction, which, from top to bottom, are a first hole section, a second hole section, a third hole section, and a fourth hole section. The diameter of the first hole section is larger than that of the second hole section, the second hole section is larger than that of the third hole section, and the third hole section is larger than that of the fourth hole section. The first and second hole sections are used to install the top cover 24 and the top cover end plate 25, while the third and fourth hole sections are used to install the second cylinder 22. The second cylinder 22 can slide axially up and down relative to the first cylinder 21.

[0045] Specifically, in this embodiment, refer to Figure 9 As shown, a square flange 211 extends radially outward from the lower end of the outer wall of the first cylinder 21. Limiting blocks 212 are provided at the periphery of the square flange 211 to engage with the upper circumferential end of the fuel assembly when the gripper assembly 10 descends to the preset end point of its stroke, thereby limiting downward displacement and preventing the gripper assembly 10 from descending excessively and colliding with the fuel rod, thus avoiding damage to the fuel rod. Furthermore, axially extending rods 213 are also provided around the upper outer wall of the first cylinder 21. The upper end of the rods 213 protrudes from the top end face of the first cylinder 21 and is used to connect with the connecting assembly 50.

[0046] Specifically, in this embodiment, refer to Figure 3 As shown, the top cover 24 is located in the first and second aperture sections, with its outer wall surface tightly fitted to the inner wall surface of the second aperture section. A stepped annular groove is formed circumferentially at the end face edge of the top cover 24 corresponding to the first aperture section. The top cover end plate 25 is an annular structure, pressed into the annular groove. The top end face of the top cover end plate 25 is flush with the top end face of the top cover 24, and its outer wall surface tightly fitted to the inner wall surface of the first aperture section, used to seal the top edge of the top cover 24. A sealing ring is provided between the middle section of the top cover 24 and the first cylinder 21, radially pressed between the top cover 24 and the first cylinder 21, achieving a static seal between them and preventing high-pressure gas inside the drive assembly 20 from leaking through the mating surface between the top cover 24 and the first cylinder 21.

[0047] Specifically, in this embodiment, refer to Figure 3 As shown, an axially extending air pipe hole is also provided at the center of the top cover 24. The air pipe hole is used to pass through and fix the air pipe 31 in the air circuit assembly 30. The inner wall of the mounting hole is tightly fitted with the outer wall of the air pipe 31. At the same time, a circular positioning groove is provided around the air pipe hole 243 on the upper end surface of the top cover 24. This groove is used to engage with the lower end port of the sleeve 32 in the air circuit assembly 30 to achieve axial positioning between the sleeve 32 and the top cover 24.

[0048] Specifically, in this embodiment, refer to Figure 3 and Figure 10 As shown, the second cylinder 22 has a stepped columnar structure, with the outer diameter of its upper shaft section being larger than that of its lower shaft section. An annular groove 221 extending axially upwards is formed on the lower end face of the upper shaft section. The inner wall of the annular groove 221 is flush with the wall of the lower shaft section, forming a continuous, flush cylindrical surface with the inner wall of the annular groove 221. The upper shaft section is located within the third bore of the first cylinder 21, and the lower shaft section is located within the fourth bore of the first cylinder 21. The outer wall of the second cylinder 22 is tightly fitted with the inner wall of the outer cylinder liner. A gas cavity is left between the top of the upper shaft section and the top cover 24. The second elastic element 23 is sleeved on the lower shaft section and partially housed within the annular groove 221. Its top abuts against the bottom of the annular groove 221, and its bottom abuts against the inner wall of the bottom of the first cylinder 21, providing axial reset driving force for the second cylinder 22. Sealing rings are provided at the top, middle, and bottom of the second cylinder 22 and between it and the first cylinder 21, and the two are interference-fitted to establish a dynamic sliding seal between the first cylinder 21 and the second cylinder 22, preventing the driving gas from moving axially between the inner and outer cylinder sleeves. When high-pressure gas is introduced into the gas cavity between the first cylinder 21 and the second cylinder 22, the gas pressure acts on the pressure-bearing end face of the second cylinder 22 and pushes it to move axially relative to the first cylinder 21, thereby converting the gas pressure energy into mechanical energy to drive the key claw 11 in the gripper assembly 10 to rotate.

[0049] Specifically, in this embodiment, refer to Figure 3 As shown, the air passage assembly 30 includes an air pipe 31 and a sleeve 32 coaxially sleeved outside the air pipe 31. The lower end of the air pipe 31 passes through the air pipe hole of the top cover 24 and communicates with the hollow cavity of the first cylinder 21, and the air pipe 31 is used to supply high-pressure gas to the drive assembly 20. The upper end of the air pipe 31 passes through the suspension assembly 40 and extends upwards for connection to an external air source. The lower end of the sleeve 32 is fitted into a circular positioning groove on the upper surface of the top cover 24, axially positioning it with the top cover 24; the upper end of the sleeve 32 extends into the interior of the suspension assembly 40, providing radial protection and axial guidance for the air pipe 31.

[0050] Specifically, in this embodiment, refer to Figure 11 and Figure 12 As shown, the suspension assembly 40 includes a sleeve 41, comprising an upper columnar portion 411 and lower circumferentially spaced extension arms 412, which are integrally formed. The sleeve 41 simultaneously serves as a load-bearing, guiding, and limiting element, effectively transmitting the lifting load while ensuring the reliability of the air passage and the directional stability of the floating alignment. A through hole 413 extending axially is provided at the center of the columnar portion 411 for the air pipe 31 to pass through and extend beyond the top of the sleeve 41. A circular groove 414 is formed circumferentially around the through hole 413 on the lower end face of the columnar portion, allowing the upper end of the sleeve 32 to extend into it. A preset axial gap is maintained between the top end face of the sleeve 32 and the top of the circular groove 414; a preset radial distance is maintained between the outer wall of the sleeve 32 and the wall of the circular groove 414 to prevent excessive swaying and interference with other components. In addition, four connecting holes 415 are provided circumferentially at the bottom end face of the columnar part for the pull ring at the upper end of the tension gauge 51 to extend into and connect; at the same time, bolt holes 416 are provided radially through the outer wall surface of the bottom end of the columnar part corresponding to the positions of each mounting hole. The bolt holes 416 are perpendicularly connected to the connecting holes 415. The upper end of the tension gauge 51 is fixedly connected to the bottom end of the sleeve 41 by passing a transverse bolt through the bolt holes 416 and the pull ring.

[0051] Specifically, in this embodiment, the lower end of the sleeve 41 consists of four circumferentially spaced extension arms 412. Each extension arm 412 is a vertically bent plate-like structure, with both its outer and inner surfaces being vertical planes. The width of the lower end of each extension arm 412 in the circumferential direction is greater than its upper width. The upper gap between two adjacent extension arms 412 is relatively large, providing installation space for the connecting assembly 50; the lower gap between two adjacent extension arms 412 is relatively small, used to engage with the upper rod 213 of the first cylinder 21. The lower end of each extension arm 412 extends into the gap between two adjacent rods 213, with a preset engagement gap in the circumferential direction. This achieves circumferential limiting between the sleeve 41 and the rod 213, preventing circumferential deflection of the gripper assembly 10 during operation, while not hindering the radial sway of the drive assembly 20 and the gripper assembly 10 relative to the suspension assembly 40.

[0052] Specifically, in this embodiment, refer to Figure 3 As shown, the connecting assembly 50 is a flexible connecting assembly, with four sets evenly distributed circumferentially between the suspension assembly 40 and the drive assembly, providing radial swing freedom for the gripper assembly 10 to achieve adaptive centering. The connecting assembly 50, from top to bottom, includes a force gauge 51, a pull rod 52, a connecting sleeve 53, a chain 54, and a connecting seat 55. The upper end of the force gauge 51 is connected to the sleeve 41, and the lower end is connected to the pull rod 52; the lower end of the pull rod 52 engages with the upper end of the connecting sleeve 53; the lower end of the connecting sleeve 53 is fixedly connected to the upper end of the chain 54; the lower end of the chain 54 is connected to the upper end of the connecting seat 55, and the lower end of the connecting seat 55 is connected to the suspension rod 213 of the first cylinder 21. The flexible connecting assembly is suspended below the suspension assembly, allowing the gripper assembly to have a horizontal offset of no more than 10 mm relative to the suspension assembly.

[0053] Specifically, in this embodiment, the tension gauge 51 is equipped with pull rings at both its upper and lower ends. The upper pull ring extends into the connecting hole 415 at the lower end of the sleeve 41 of the suspension assembly 40 and is fixedly connected to the sleeve by a transverse bolt and a lock nut. The lower pull ring is used to connect to the pull rod 52. The tension gauge 51 is used to monitor the axial load changes of each key claw 11 during gripping, unloading, and hoisting processes to determine whether the fuel assembly is in a reliable gripping state. During hoisting, it identifies abnormal working conditions such as jamming, friction, or collision through load fluctuations, providing load feedback and fault warnings to the operator.

[0054] Optionally, the range of the force gauge is 0-2000N.

[0055] Specifically, in this embodiment, the pull rod 52 has a stepped shaft structure, with the outer diameter of the upper shaft section being smaller than that of the lower shaft section, forming a stepped surface between them. An axial mounting hole is provided at the center of the upper shaft section for the lower pull ring of the force gauge 51 to extend into and be installed. Simultaneously, a radially penetrating bolt hole is provided on the side wall of the upper shaft section, through which a transverse bolt passes, securing the pull rod 52 to the lower pull ring of the force gauge 51. The lower shaft section of the pull rod 52 forms a flange for engaging with the upper end of the connecting sleeve 53.

[0056] Specifically, in this embodiment, the connecting sleeve 53 is a hollow cylindrical shape with openings at both ends. A circumferential inner wall is provided in the axial center, dividing the internal cavity axially into an upper receiving cavity and a lower receiving cavity. An annular flange is formed radially inward on the inner wall of the top end of the connecting sleeve 53. The inner diameter of the opening of the upper receiving cavity is smaller than its inner diameter. The lower end shaft of the pull rod 52 is axially confined within the upper receiving cavity of the connecting sleeve 53. The lower receiving cavity of the connecting sleeve 53 is used to accommodate the upper end of the chain 54. Bolt holes are provided on the lower shaft end wall, penetrating radially through both side walls. A transverse bolt passes through the bolt holes and the connecting hole at the upper end of the chain 54, fixing the upper end of the chain 54 to the lower receiving cavity.

[0057] Specifically, in this embodiment, the chain 54 is a flexible chain structure formed by multiple chain links linked together sequentially. The upper chain link extends into the lower receiving cavity of the connecting sleeve 53 and is fixed by transverse bolts. The lower chain link is a semi-circular ring, connected to the connecting seat 55 below. The overall function of the chain 54 is to transfer the lifting load of the suspension assembly 40 to the lower components, while simultaneously providing radial floating compensation for the gripper assembly 10 by utilizing the relative degrees of freedom of movement between the chain links.

[0058] Specifically, in this embodiment, the connecting seat 55 has a stepped block structure, with the thickness of its upper end being greater than that of its lower end. Two mounting holes are formed on the upper surface of the connecting seat 55, and the two ends of the semi-circular ring at the lower end of the chain 54 are respectively inserted into the two mounting holes and fixedly connected by welding or press-fitting. An axial mounting hole is formed at the lower end of the connecting seat 55 for the suspension rod 213 to pass through. A radially penetrating bolt hole is also formed on the side wall of the lower end of the connecting seat 55, through which a transverse bolt passes and through the bolt hole and the corresponding connecting hole on the suspension rod 213, fixing the two together.

[0059] In another embodiment, four steel wire ropes 60 are fixedly connected to the key claw sleeve 12, each corresponding to one of the four key claw sleeves 12. The four steel wire ropes 60 extend upwards and converge at a steel wire rope fixing member 61, which is positioned above the sleeve 41. When the drive assembly 20 fails to drive the key claw 11 to open normally due to air supply interruption, seal failure, or internal jamming, the gripper assembly 10 will be unable to detach from the fuel assembly, posing a risk that the gripper cannot be extracted from the fuel assembly. By providing the steel wire ropes 60, a manual emergency unlocking channel independent of the pneumatic drive system can be provided under the aforementioned fault conditions. The operator pulls the steel wire rope fixing member 61 upwards, causing the four steel wire ropes 60 to pull the key claw sleeve 12 upwards simultaneously, forcing the key claw 11 to rotate around its mounting fulcrum to avoid it, thereby achieving synchronous opening of the key claw 11 and completing the unlocking and detachment from the fuel assembly.

[0060] Specifically, one end of each wire rope 60 is fixedly connected to the key claw sleeve 12, and the other end passes through the inclined hole 214 opened in the lower end side wall of the first cylinder 21 and extends upward along the outer wall surface of the first cylinder 21. An axial gap is reserved between the upper end of the first cylinder 21, the rod 213, and the outer wall surface of the first cylinder 21 for the wire rope 60 to pass through. After passing through the axial gap upward, each wire rope 60 passes through the gap between the connecting assembly 50 and the sleeve 32 in sequence, and through the inclined through hole 417 opened at the top of the annular groove of the columnar part at the lower end of the sleeve 41, and finally converges at the wire rope fixing member 61 above the sleeve 41 and is fixedly connected. The inclined hole 214 in the lower end side wall of the first cylinder 21 is opened on the wall surface of the fourth diameter section, connecting from the bottom end face to the outer wall surface, guiding the wire rope 60 to the outside through the inclined hole, so as to avoid the wire rope 60 passing through the inside of the first cylinder 21 and affecting the pneumatic sealing performance. The inclined through holes 417 of the cylindrical part of the sleeve 41 are distributed circumferentially around the mounting through hole of the air pipe 31, and each inclined through hole 417 is inclined radially inward from bottom to top, so that each wire rope 60 gradually converges towards the center as it extends upward.

[0061] With the above configuration, when the pneumatic drive function malfunctions and the key claw 11 cannot open normally, the steel wire rope fixing member 61 can be manually pulled upwards, causing the four steel wire ropes 60 to simultaneously pull the key claw sleeve 12 upwards. This allows each key claw 11 to retract and avoid contact, enabling manual unlocking and disengagement from the fuel assembly. This avoids the risk that the gripper cannot be pulled out of the fuel assembly in a malfunctioning state. Simultaneously, the steel wire rope 60 is fixedly connected to the key claw sleeve 12 rather than directly to the key claw 11, preventing the steel wire rope 60 from repeatedly bending with each rotation of the key claw 11, effectively extending the service life of the steel wire rope 60 and improving the reliability of the emergency operation mechanism.

[0062] The above are merely several specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0063] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0064] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A fuel assembly gripper that achieves self-locking by attaching fuel, characterized in that, include: Grab assembly (10) for grabbing or releasing fuel assembly; A drive assembly (20) is connected above the gripper assembly (10) and is used to provide driving force to the gripper assembly (10); Gas circuit assembly (30) for supplying high-pressure gas to the drive assembly (20); A suspension assembly (40) is disposed above the drive assembly (20) for connection with external hoisting equipment; And a connecting component (50) connected between the suspension component (40) and the drive component (20); The gripper assembly (10) is provided with a load-bearing self-locking structure. When the gripper assembly (10) is loaded with fuel assembly, it automatically maintains a locked state by the gravity of the fuel assembly.

2. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 1, characterized in that: The connecting component (50) is a flexible connecting component that provides radial yaw degree of freedom for the gripper assembly (10).

3. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 1 or 2, characterized in that: The gripper assembly (10) includes a base (13), a key claw (11) mounted on the base (13), and a reset structure. Multiple key claws (11) are spaced apart along the circumference and are rotatably mounted on the base (13). The reset structure is mounted inside the base (13) and located below the key claws (11).

4. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 3, characterized in that: The key claw (11) has an extended end and a driving end. The extended end extends out of the base (13) and is used to form a mounting fit with the fuel assembly. The driving end is located inside the base (13) and is used to receive driving force to drive the key claw (11) to rotate.

5. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 4, characterized in that: The reset structure includes a support rod (14) and a first elastic element (15) sleeved outside the support rod (14). The support rod (14) is located below the driving end of the key claw (11). The first elastic element (15) provides axial reset force to the driving end of the key claw (11) through the support rod (14).

6. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 3, characterized in that: The gripper assembly (10) also includes a key claw sleeve (12), which is fitted on the outside of the key claw (11). The key claw sleeve (12) is provided with a wire rope connection part, which is used to drive the key claw (11) to rotate and retract in an emergency by pulling the wire rope from the outside.

7. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 3, characterized in that: The lower end of the base (13) is provided with a tapered guide structure, which is a tapered surface whose outer diameter gradually decreases from top to bottom.

8. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 1, characterized in that: The drive assembly (20) includes a first cylinder (21) and a second cylinder (22) at least partially disposed inside the first cylinder (21). The lower end of the second cylinder (22) extends out of the first cylinder (21) and is connected to the gripper assembly (10). The second cylinder (22) can slide axially relative to the first cylinder (21) to drive the gripper assembly (10) to perform gripping or releasing actions.

9. The fuel assembly gripper that achieves self-locking by loading fuel according to claim 8, characterized in that: The drive assembly (20) further includes a second elastic member (23), the two ends of which act on the first cylinder (21) and the second cylinder (22) respectively, for providing axial restoring force to the second cylinder (22).

10. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 8, characterized in that: The first cylinder (21) has a top cover (24) at its upper end port. The top cover (24) has a through hole for connecting the air circuit assembly (30). High-pressure gas enters the first cylinder (21) through the through hole and pushes the second cylinder (22) to slide axially relative to the first cylinder (21).

11. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 1, characterized in that: The air passage assembly (30) includes an air tube (31) and a sleeve (32) coaxially sleeved outside it, with the lower end of the air tube (31) connected to the drive assembly (20).

12. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 1, characterized in that: The suspension assembly (40) includes a sleeve (41), the upper end of which is provided with an axial through hole (413) for the air passage assembly (30) to pass through and extend; the lower end of the sleeve (41) is provided with a plurality of circumferentially spaced extension arms (412), each of the extension arms (412) being circumferentially limited to the upper end of the drive assembly (20).

13. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 1 or 2, characterized in that: A tension gauge (51) is provided on the connecting assembly. The tension gauge (51) is connected to the lower end of the suspension assembly (40) and is used to detect the axial load of the gripper assembly (10).

14. The fuel assembly gripper that achieves self-locking by mounting fuel according to claim 1, characterized in that: It also includes an emergency unlocking mechanism, which includes a traction member, one end of which is connected to the gripper assembly (10), and the other end of which bypasses the drive assembly (20), passes through the suspension assembly (40), and extends upward.

15. A fuel assembly, used in conjunction with the fuel assembly gripper according to any one of claims 1 to 14, characterized in that: The fuel assembly has an inwardly protruding engagement flange at its top, and each engagement flange is used to engage and mount with the gripper assembly (10).

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