Reactor top cover lifting appliance mounting device and nuclear power station maintenance equipment

Abstract

The utility model provides a reactor top cover lifting appliance mounting device and nuclear power station maintenance equipment, and the reactor top cover lifting appliance mounting device comprises a shaft pin which is used for being inserted into pin holes of a first lifting appliance part and a second lifting appliance part; one end of the screw rod is fixedly connected with the shaft pin, and the screw rod is used for driving the shaft pin to be inserted into the pin hole; the fastening handle is in threaded connection with the other end of the screw rod, and the fastening handle can rotate relative to the screw rod; the guide piece is movably arranged on the screw rod in a sleeving mode and located between the fastening handle and the shaft pin, and the guide piece is used for being connected with the end face of the second lifting appliance component in an abutting mode and limiting movement of the guide piece; and when the fastening handle rotates relative to the screw rod, the screw rod is driven to move in the axial direction of the pin hole, so that the shaft pin can be driven by the screw rod to be sequentially inserted into the pin holes of the second lifting appliance component and the first lifting appliance component. And the first lifting appliance part, the second lifting appliance part and the shaft pin are connected through the screw rod, so that the mounting quality and the mounting efficiency are improved, and the construction time is shortened.

Description

Technical Field

[0001] This utility model relates to the technical field of nuclear power plant maintenance equipment, and more specifically, to a reactor top cover hoisting device and nuclear power plant maintenance equipment. Background Technology

[0002] In nuclear power plant unit overhaul operations, the connection between the reactor top cover and the triangular lifting device is traditionally assembled using a manual hammering process. Specifically, after the lifting device is hoisted to the designated work position using a ring crane, multiple workers must work together in a confined space to assemble the axle pin. This process requires workers to use copper hammering tools to impact the pin, causing it to pass through the mating pin hole between the star-shaped bracket and the lower lifting rod.

[0003] Engineering practice has verified that this traditional process has the following technical defects: First, on the stack top working platform with a vertical height of more than 10 meters, manual striking operations are prone to tool falling risks, posing a safety hazard; second, because the fit clearance between the pin and the pin hole is controlled within the range of 0.1-0.15mm, it is difficult to accurately control the direction of force during the striking process, resulting in mechanical damage such as scratches and burrs on the mating surfaces, leading to a high rework rate; third, the efficiency of multiple people working together in a confined space is low, and the time taken for a single assembly is long, directly affecting the progress of the critical path of major overhaul; in addition, the instantaneous impact load generated by metal impact may cause micro-deformation of the lifting device structure, affecting the positioning accuracy of the equipment. Utility Model Content

[0004] The purpose of this utility model is to provide a reactor top cover lifting device and nuclear power plant maintenance equipment to solve the technical problems of low operator safety, high rework rate, long assembly time and low positioning accuracy when connecting the reactor top cover and the triangular lifting device in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] In a first aspect, a reactor top cover lifting device is provided, comprising:

[0007] A pivot pin is used to insert into the pin holes of the first and second lifting components;

[0008] A screw, one end of which is inserted into the pin and used to fix it to the pin, and is used to drive the pin to be inserted into the pin hole;

[0009] A fastening handle is threaded to the other end of the screw, and the fastening handle is rotatable relative to the screw.

[0010] A guide member is movably sleeved on the screw and located between the fastening handle and the shaft pin. The guide member is used to abut against the end face of the second lifting device component to restrict the movement of the guide member.

[0011] When the fastening handle rotates relative to the screw, it drives the screw to move axially along the pin hole, so that the pin can be inserted into the pin holes of the second lifting device component and the first lifting device component in sequence under the drive of the screw.

[0012] By adopting the above technical solution, the first lifting tool component, the second lifting tool component, and the shaft pin are connected by a screw. The screw transmits axial force to achieve the alignment, correction, and installation of the first and second lifting tool components. After the entire reactor top cover lifting tool installation device is installed on site, a large torque can be obtained by rotating the tightening handle. The resulting lifting force replaces the impact force generated by the previous hammering. The threaded lifting force is greater, reducing the limitation of on-site space. The hammering process has less room for movement, is more stable, and the direction is controllable. The correction process is safer and requires no personnel assistance. It is easier to achieve alignment, improves installation quality and efficiency, and shortens construction time.

[0013] In one embodiment, the guide includes a first guide portion and an abutment portion. The shape of the first guide portion matches the shape of the pin hole, and the first guide portion is used to have a clearance fit with the pin hole. The abutment portion is located on the side of the first guide portion away from the pin hole of the second lifting device component, and the abutment portion is used to abut against the end face of the second lifting device component.

[0014] In one embodiment, the guide further includes a second guide connected to the first guide, the second guide being located on the side of the first guide away from the fastening handle, and the cross-sectional diameter of the second guide gradually decreasing from the end closer to the first guide to the end farther away from the second guide.

[0015] In one embodiment, the radial dimension of the abutment portion is greater than the radial dimension of the pin hole.

[0016] In one embodiment, the reactor top cover lifting device further includes a push-off sleeve, which is used to be fitted onto the first guide portion and the second guide portion, and the radial dimension of the push-off sleeve is larger than the radial dimension of the pin hole.

[0017] In one embodiment, the axial dimension of the push-off sleeve is greater than the axial dimension of the first guide portion.

[0018] In one embodiment, when the push-off sleeve is fitted onto the first guide portion, the end of the push-off sleeve near the pin hole is flush with the end of the second guide portion near the pin hole.

[0019] In one embodiment, the fastening handle includes a nut connected to the screw and a plurality of handles disposed circumferentially on the nut.

[0020] In one embodiment, the circumferential surface of the pin is provided with textures that engage with the pin hole to restrict the pin from rotating about its own axis.

[0021] Secondly, a nuclear power plant maintenance equipment is provided, including a main body of the nuclear power plant maintenance equipment and the aforementioned reactor top cover lifting device, wherein the main body of the nuclear power plant maintenance equipment is connected to the reactor top cover lifting device.

[0022] By adopting the above technical solution, in addition to the advantages of the reactor top cover lifting device of the above embodiment, the nuclear power plant maintenance equipment of this embodiment also has the advantage of being easy for operators to operate.

[0023] Further explanation is needed regarding the invention of this nuclear power plant maintenance equipment, which primarily addresses the following on-site issues: 1. It enables use in confined spaces. 2. It generates greater axial installation force than previous methods. 3. It guides the installation direction to prevent the axle pin from misaligning. 4. It avoids the potential for equipment and personnel damage caused by previous installation (hammering) methods. 5. It improves axle pin installation efficiency, ensuring equipment installation is completed within a limited path and timeframe. 6. It can be used for the installation of top cover lifting devices for similar units. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a three-dimensional structural diagram of the reactor top cover lifting device provided in this embodiment of the utility model.

[0026] Figure 2 This is an exploded view of the reactor top cover lifting device provided in this embodiment of the utility model.

[0027] Figure 3 This is a perspective sectional view of the first and second lifting device components provided in this embodiment of the utility model, wherein a small portion of the axle pin is inserted into the pin hole.

[0028] Figure 4 This is a perspective sectional view of the first and second lifting device components provided in this embodiment of the utility model, wherein most of the shaft pin is inserted into the pin hole.

[0029] Figure 5 This is a three-dimensional structural diagram of the guide and push-off sleeve provided in the embodiment of this utility model.

[0030] Figure 6 This is an assembly diagram of the guide and push-off sleeve provided in this embodiment of the utility model.

[0031] Figure 7 This is a three-dimensional structural diagram of the reactor top cover lifting device provided in this embodiment of the utility model, wherein the guide sleeve is provided with a push-off sleeve.

[0032] Figure 8 This is a three-dimensional structural diagram of the reactor top cover lifting device provided in this embodiment of the utility model. In this diagram, the guide sleeve is provided with a push-off sleeve, and the shaft pin is fully inserted into the pin hole.

[0033] The labels for the attached figures are as follows:

[0034] 100. First lifting device component; 200. Second lifting device component; 201. Support lug; 300. Pin hole;

[0035] 1. Screw; 2. Shaft pin; 3. Guide component; 4. Fastening handle; 5. Push-off sleeve;

[0036] 21. Threaded hole; 30. Through hole; 31. First guide part; 32. Second guide part; 33. Abutment part; 41. Nut; 42. Handle. Detailed Implementation

[0037] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0038] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be located directly on or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component.

[0039] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or the number of technical features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. The specific implementation of this utility model is described in more detail below with reference to specific embodiments:

[0041] like Figure 1 and Figure 2 As shown in the figure, this utility model provides a reactor top cover lifting device, which is used to install the reactor top cover onto the lifting device, thereby achieving a fixed connection between the reactor top cover and the lifting device, and thus realizing the lifting of the reactor top cover. The reactor top cover lifting device provided in this embodiment can reduce damage to the reactor top cover and the lifting device during the installation process, improve the safety and efficiency of the installation process, and shorten the installation time. The following is a detailed description of the specific implementation method:

[0042] The reactor top cover lifting device in this embodiment includes:

[0043] The shaft pin 2 is used to be inserted into the pin hole 300 of the first lifting device component 100 and the second lifting device component 200;

[0044] Screw 1, one end of screw 1 is fixedly connected to shaft pin 2, used to drive shaft pin 2 to be inserted into pin hole 300;

[0045] The fastening handle 4 is threadedly connected to the other end of the screw 1, and the fastening handle 4 can rotate relative to the screw.

[0046] The guide 3 is movably sleeved on the screw 1 and located between the fastening handle 4 and the shaft pin 2. The guide 3 is used to abut against the end face of the second lifting device component 200.

[0047] When the screw 1 rotates relative to the fastening handle 4, it drives the screw 1 to move axially along the pin hole 300, so that the shaft pin 2 can be inserted into the pin holes 300 of the second lifting device component 200 and the first lifting device component 100 in sequence under the drive of the screw 1.

[0048] Specifically, screw 1 refers to a rod-shaped component. Screw 1 has a preset length and external threads are provided on the circumferential surface of screw 1. One end of screw 1 is used to be threadedly connected to the end of pin 2 to achieve a fixed connection between the two.

[0049] The pin 2 is a component used to insert into the pin hole 300 of the first lifting device component 100 and the pin hole 300 of the second lifting device component 200. In this embodiment, the first lifting device component 100 is a star-shaped bracket, and the second lifting device component 200 is a lower lifting rod. The first lifting device component 100 is the part connected to the reactor top cover, and the second lifting device component 200 is the part connected to the triangular lifting device. The first lifting device component 100 is provided with a pin hole 300, and the second lifting device component 200 is also provided with a pin hole 300. When the two are connected, their pin holes 300 are aligned. At this time, the pin 2 is inserted into the pin holes 300 of both, thereby realizing the connection between the first lifting device component 100 and the second lifting device component 200. The end of the pin 2 near the screw 1 is provided with a threaded hole 21. One end of the screw 1 is inserted into the threaded hole 21 and threadedly engaged with the threaded hole 21, thereby realizing the fixed connection between the screw 1 and the pin 2.

[0050] The guide 3 is a component used to guide the shaft pin 2 into the pin hole 300. The guide 3 has a through hole 30. The radial dimension of the screw 1 is slightly smaller than the diameter of the through hole 30. In this way, the screw 1 and the through hole 30 are clearance-fitted, so that the screw 1 can move freely along the axial direction of the pin hole 300 within the through hole 30.

[0051] The fastening handle 4 is a component used to drive the screw 1 to move axially along the pin hole 300. The fastening handle 4 is operated by the operator and is threadedly connected to the other end of the screw 1. The fastening wrench 4 can rotate relative to the screw 1. In this way, the torque generated by the fastening wrench 4 drives the screw 1 to move axially along the pin hole 300, thereby driving the shaft pin 2 to be inserted into the pin hole 300.

[0052] like Figure 3 and Figure 4 As shown, the working principle of the reactor top cover lifting device provided in this embodiment is as follows:

[0053] The second lifting device component 200 in this embodiment has two lugs 201, each lug 201 having a pin hole 300. The first lifting device component 100 extends between the two lugs 201, enabling the first lifting device component 100 and the second lifting device component 200 to mate. The pin holes 300 of the two components are aligned. A shaft pin 2 is inserted through the pin hole 300 on one of the lugs 201 of the second lifting device 200. Without the installation device, the shaft pin 2 can only be partially inserted. One end of a screw 1 is inserted into the threaded hole 21 of the shaft pin 2, while the other end of the screw 1 protrudes from the pin hole 300 of the other lug 201 of the second lifting device 200. A guide member 3 is then fitted onto the protruding end of the screw 1 and abuts against the second lifting device 200. Thus, the shaft pin 2 and the guide member 3 are located on opposite sides of the first lifting device 100. Simultaneously, the fastening handle 4 is threaded onto the end of the screw 1 equipped with the guide member 3. The operator rotates the fastening handle 4, causing it to move axially along the pin hole 300. Since the guide member 3 abuts against the second lifting device component 200, the guide member 3 remains stationary relative to the second lifting device component 200. There is friction between the pin 2 and the wall of the pin hole 300. At the same time, the pin 2 is subjected to an axial force from the screw 1, allowing the pin 2 to be inserted into the pin hole 300 along its axial direction. When the pin 2 abuts against the guide member 3, the insertion of the pin 2 into the pin hole 300 is completed, realizing the connection between the first lifting device component 100 and the second lifting device component 200.

[0054] By adopting the above technical solution, the first lifting tool component 100, the second lifting tool component 200, and the shaft pin 2 are connected by the screw 1. The screw 1 transmits axial force to realize the centering, correction, and installation of the first lifting tool component 100 and the second lifting tool component 200. After the entire reactor top cover lifting tool installation device is installed on site, a large torque can be obtained by rotating the fastening handle 4. The resulting lifting force replaces the impact force generated by the previous hammering. The threaded lifting force is greater, reducing the limitation of the site space. The hammering process has a small range of motion, making it more stable and directionally controllable. The correction process is safer and does not require personnel assistance. It is easier to achieve centering and correction, improving the installation quality and efficiency, and shortening the construction time.

[0055] Please refer to it again. Figure 2 In one embodiment, the guide member 3 includes a first guide portion 31 and an abutment portion 33. The shape of the first guide portion 31 matches the shape of the pin hole 300. The first guide portion 31 is used to fit with the pin hole 300 with a clearance. The abutment portion 33 is located on the side of the first guide portion 31 away from the pin hole 300 of the second lifting device component 200. The abutment portion 33 is used to abut against the end face of the second lifting device component 200.

[0056] Specifically, since the first guide part 31 is sleeved on the screw 1, when the first guide part 31 can be inserted into the pin hole 300, the first guide part 31 adjusts the screw 1 to be located on the axis of the pin hole 300 due to the clearance fit between the first guide part 31 and the pin hole 300, thus maintaining the coaxiality of the screw 1 and the shaft pin 2.

[0057] In addition, the abutment portion 33 is used to fix the first guide portion 31 relative to the pin hole 300.

[0058] By adopting the above technical solution, it is beneficial for the screw 1 to apply tension to the pin 2 in the axial direction of the pin hole 300.

[0059] In one embodiment, the guide member 3 further includes a second guide portion 32 connected to the first guide portion 31. The second guide portion 32 is located on the side of the first guide portion 31 away from the fastening handle 4, and the cross-sectional diameter of the second guide portion 32 gradually decreases from the end closer to the first guide portion 31 to the end farther away from the second guide portion 32.

[0060] Specifically, the second guide portion 32 refers to the component used to guide the first guide portion 31 into the pin hole 300; the second guide portion 32 is connected to the first guide portion 31 and is located on the side close to the pin hole 300. In this way, when the guide member 3 is aligned with the pin hole 300 and inserted, since the second guide portion 32 is tapered, even if the guide member 3 is slightly offset during insertion, the second guide portion 32 can adjust the first guide portion 31 to a position coaxial with the pin hole 300, thereby correcting the pin 2.

[0061] By adopting the above technical solution, the correction of pin 2 is made easier to achieve.

[0062] In one embodiment, the guide 3 further includes an abutment portion 33, which is located on the side of the first guide portion 31 opposite to the second guide portion 32, and the radial dimension of the abutment portion 33 is greater than the radial dimension of the pin hole 300.

[0063] By adopting the above technical solution, the abutting part 33 refers to the component used to abut against the second lifting device component 200 to prevent the guide 3 from being fully inserted into the pin hole 300.

[0064] like Figure 5 and Figure 6 As shown, in one embodiment, the reactor top cover lifting device further includes a push-off sleeve 5, which is used to be fitted onto the first guide portion 31 and the second guide portion 32. The radial dimension of the push-off sleeve 5 is larger than the radial dimension of the pin hole 300.

[0065] Please refer to the following: Figure 7 and Figure 8Specifically, before the guide component 3 is fitted with the push-off sleeve 5, the first lifting tool component 100 and the second lifting tool component 200 are initially aligned, and then connected to the shaft pin 2 via the screw 1. Rotating the fastening handle 4, the thread torque of the threaded parts and the cooperation with the guide component 3 achieve a stable and obvious alignment effect. Rotating the fastening handle 4, when the shaft pin 2 passes through the pin hole 300 and contacts the guide component 3, observe the depth of the shaft pin 2's entry and the sudden change in force when rotating the fastening handle 4. At this point, remove the guide component 3, while the screw 1 remains connected to the shaft pin 2. After installing the push-off sleeve 5 on the guide component 3, reassemble the tool. At this point, since most of the pins 2 have already entered the pin holes 300, the guiding effect of the guide 3 is not needed. However, the guide 3 needs to be removed from the pin holes 300 so that the pins 2 can be fully inserted into the pin holes 300. Therefore, the push sleeve 5 is pressed against the second lifting tool component 200 to prevent the guide 3 from being inserted into the pin holes 300. Continue to tighten the fastening handle 4 until the pins 2 and the guide 3 are in contact again. Then the tool can be removed to complete the entire alignment and connection process.

[0066] By adopting the above technical solution, the shaft pin 2 is fully inserted into the pin hole 300 to realize the installation of the shaft pin 2.

[0067] In one embodiment, the axial dimension of the push-off sleeve 5 is greater than the axial dimension of the first guide portion 31.

[0068] Specifically, the axial dimension refers to the dimension along the axial direction of the shaft hole.

[0069] By adopting the above technical solution, when the push-off sleeve 5 is fitted onto the first guide part 31 and abuts against the second lifting device component 200, the first guide part 31 is disengaged from the pin hole 300, thus preventing the first guide part 31 from blocking the installation of the shaft pin 2.

[0070] In one embodiment, when the push-off sleeve 5 is fitted onto the first guide portion 31, the end of the push-off sleeve 5 near the pin hole 300 is flush with the end of the second guide portion 32 near the pin hole 300.

[0071] By adopting the above technical solution, when the push-off sleeve 5 is fitted onto the first guide part 31 and abuts against the second lifting device component 200, the first guide part 31 and the second guide part 32 are disengaged from the pin hole 300, thus preventing the first guide part 31 from blocking the installation of the shaft pin 2.

[0072] Please refer to it again. Figure 2 In one embodiment, the fastening handle 4 includes a nut 41 connected to the screw 1 and a plurality of handles 42 disposed circumferentially on the nut 41.

[0073] Specifically, the nut 41 is used for threaded connection with the screw 1. The nut 41 can rotate relative to the screw 1 about an axis, thereby driving the screw 1 to move axially along the pin hole 300.

[0074] By adopting the above technical solution, it is easier for operators to operate the fastening handle.

[0075] In one embodiment, the circumferential surface of the pin 2 is provided with textures that cooperate with the pin hole 300 to restrict the rotation of the pin 2 around its own axis.

[0076] Specifically, the grooves are used to restrict the pin 2 to move only along the axial direction of the pin hole 300. In this way, when the fastening handle 4 rotates relative to the screw 1 about the axis, the torque of the fastening handle 4 is converted into the force that causes the screw 1 to move axially along the pin hole 300.

[0077] By adopting the above technical solution, the friction between the shaft pin 2 and the hole wall of the pin hole 300 is improved, making the shaft pin 2 more tightly inserted into the pin hole 300.

[0078] Secondly, a nuclear power plant maintenance equipment is provided, including a main body of the nuclear power plant maintenance equipment and the aforementioned reactor top cover lifting device, wherein the main body of the nuclear power plant maintenance equipment is connected to the reactor top cover lifting device.

[0079] By adopting the above technical solution, in addition to the advantages of the reactor top cover lifting device of the above embodiment, the nuclear power plant maintenance equipment of this embodiment also has the advantage of being easy for operators to operate.

[0080] Further explanation is needed regarding the invention of this nuclear power plant maintenance equipment, primarily aimed at solving the following on-site issues: 1. It can be used in confined spaces on-site. 2. It can generate greater axial installation force than previous solutions. 3. It can guide the installation direction to prevent the shaft pin 2 from deviating. 4. It avoids the potential for equipment and personnel damage caused by previous installation (hammering). 5. It improves the installation efficiency of the shaft pin 2, ensuring that the equipment installation is completed within a limited path time. 6. It can be used for the installation of top cover lifting devices for similar units.

[0081] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A reactor top cover lifting device, characterized in that, include: A pivot pin is used to insert into the pin holes of the first and second lifting components; A screw, one end of which is fixedly connected to the shaft pin, for driving the shaft pin to be inserted into the pin hole; A fastening handle is threaded to the other end of the screw, and the fastening handle is rotatable relative to the screw. A guide member is movably sleeved on the screw and located between the fastening handle and the shaft pin. The guide member is used to abut against the end face of the second lifting device component. When the fastening handle rotates relative to the screw, it drives the screw to move axially along the pin hole, so that the pin can be inserted into the pin holes of the second lifting device component and the first lifting device component in sequence under the drive of the screw.

2. The reactor top cover lifting device as described in claim 1, characterized in that, The guide includes a first guide portion and an abutment portion. The shape of the first guide portion matches the shape of the pin hole. The first guide portion is used to have a clearance fit with the pin hole. The abutment portion is located on the side of the first guide portion away from the pin hole of the second lifting device component. The abutment portion is used to abut against the end face of the second lifting device component.

3. The reactor top cover lifting device as described in claim 2, characterized in that, The guide also includes a second guide connected to the first guide. The second guide is located on the side of the first guide away from the fastening handle, and the cross-sectional diameter of the second guide gradually decreases from the end closer to the first guide to the end farther away from the second guide.

4. The reactor top cover lifting device as described in claim 2, characterized in that, The radial dimension of the abutment portion is greater than the radial dimension of the pin hole.

5. The reactor top cover lifting device as described in claim 3, characterized in that, The reactor top cover lifting device also includes a push-off sleeve, which is used to be fitted onto the first guide portion and the second guide portion. The radial dimension of the push-off sleeve is larger than the radial dimension of the pin hole.

6. The reactor top cover lifting device as described in claim 5, characterized in that, The axial dimension of the push-off sleeve is greater than the axial dimension of the first guide portion.

7. The reactor top cover lifting device as described in claim 6, characterized in that, When the push-off sleeve is fitted onto the first guide portion, the end of the push-off sleeve near the pin hole is flush with the end of the second guide portion near the pin hole.

8. The reactor top cover lifting device as described in any one of claims 1 to 7, characterized in that, The fastening handle includes a nut connected to the screw and a plurality of handles disposed circumferentially on the nut.

9. The reactor top cover lifting device as described in any one of claims 1 to 4, characterized in that, The circumferential surface of the pin has grooves that cooperate with the pin hole to restrict the pin from rotating about its own axis.

10. A nuclear power plant maintenance equipment, characterized in that, The device includes a main body of nuclear power plant maintenance equipment and a reactor top cover lifting device as described in any one of claims 1 to 9, wherein the main body of the nuclear power plant maintenance equipment is connected to the reactor top cover lifting device.

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