Underwater cotter pin replacement equipment and locking pin introduction device for nuclear power plants

Abstract

The present invention relates to an underwater cotter pin replacement device and a locking pin introduction device for a nuclear power plant. The locking pin introduction device is used for the underwater cotter pin replacement device of a nuclear power plant and comprises an arc-shaped track, a locking pin introduction mechanism installed on the track and movable along the track; and a driving device connected to the locking pin introduction mechanism and used to drive the locking pin introduction mechanism to move on the track. Since the locking pin introduction mechanism is installed on the arc-shaped track and can move along the track under the drive of the driving device; the locking pin introduction mechanism can install the locking pin in nuts set at different angles in the horizontal direction, thereby avoiding unsafe factors caused by human operation, improving installation efficiency and the safety of replacing cotter pin assemblies.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power plant maintenance, and more particularly to underwater cotter pin replacement equipment and a locking pin introduction device for a nuclear power plant. Background Art

[0002] like Figures 1 to 3 As shown, a cotter pin assembly 100 in the related art may include a cotter pin 101, a nut 102, a locking pin 103, and a locking block 104. The cotter pin 101 is arranged vertically during assembly, with notches at its top and bottom for threaded connection with the nut 102, which contains a hexagonal nut. The locking pin 103 can be mounted on the nut 102 perpendicular to its axial direction. When the nut 102 rotates, the locking pin 103 rotates with the nut 102. The locking block 104 has a protrusion at its bottom that mates with the notch at the top of the cotter pin 101. If the locking block 104 does not rotate relative to the cotter pin 101, the cotter pin 101 cannot rotate relative to the nut 102. When the components of the cotter pin assembly 100 are in the assembled position, the locking pin 103 and the locking block 104 are welded together to secure them, preventing relative rotation between the cotter pin 101 and the nut 102.

[0003] When installing the cotter pin assembly 100 in the reactor, it is not easy to align the locking pin 103 with the nut 102 during introduction, and the gap between the hole on the nut 102 and the locking pin 103 is unstable, which is not convenient for installation. Therefore, manual operation is usually required, the replacement cost is high, and the efficiency is low; and the replacement risk is high, which may cause personnel to be exposed to radiation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an improved underwater cotter pin replacement device and a locking pin introduction device for a nuclear power plant.

[0005] The technical solution adopted by the present invention to solve its technical problems is: constructing a locking pin introduction device for use in underwater cotter pin replacement equipment of nuclear power plants; comprising a track in an arc shape; a locking pin introduction mechanism installed on the track and movable along the track; and a driving device connected to the locking pin introduction mechanism for driving the locking pin introduction mechanism to move on the track.

[0006] In some embodiments, the arc-shaped track has an effective travel of at least 120°.

[0007] In some embodiments, the locking pin introduction mechanism includes a locking pin ejection cylinder and a locking pin loading position connected to one end of the locking pin ejection cylinder, and the locking pin loading position can be loaded with at least one locking pin.

[0008] In some embodiments, the locking pin introduction mechanism includes a guide channel, and the guide channel is in communication with the locking pin loading position.

[0009] In some embodiments, the locking pin introduction mechanism includes a hexagonal head connected to one end of the guide channel in the guiding direction, the hexagonal head is provided with a guide groove, and the locking pin is installed on the nut through the guide groove.

[0010] In some embodiments, the locking pin introduction mechanism includes a seat connected to the locking pin ejection cylinder, and the seat is installed on the track.

[0011] In some embodiments, the locking pin ejection cylinder includes a drive motor, a lead screw connected to the drive motor, and a lead screw nut mounted on the lead screw, wherein the lead screw nut can move axially along the lead screw.

[0012] In some embodiments, the locking pin ejection cylinder includes a cylinder body, a screw nut guide rod connected to the cylinder body along the axial direction of the screw, and a screw nut seat connected to the screw nut guide rod, and the screw nut is installed on the screw nut seat.

[0013] In some embodiments, the locking pin ejection cylinder includes a push rod seat connected to the screw nut and a push rod installed on the push rod seat along the axial direction of the screw, and the push rod is used to guide the locking pin into the nut.

[0014] An underwater cotter pin replacement device for a nuclear power plant is also constructed, comprising any one of the locking pin introduction devices described above, and a three-coordinate platform, wherein the locking pin introduction device is mounted on the three-coordinate platform.

[0015] In some embodiments, the three-coordinate platform includes a base and a first movable platform movably mounted on the base, wherein the first movable platform can move relative to the base along the Y direction.

[0016] In some embodiments, the three-coordinate platform includes a second mobile platform movably mounted on the first mobile platform, and the second mobile platform can move relative to the first mobile platform along the Z direction.

[0017] In some embodiments, the underwater cotter pin replacement device for a nuclear power plant includes a robotic arm installed on the second mobile platform.

[0018] In some embodiments, the three-coordinate platform includes a third mobile platform movably mounted on the second mobile platform, the third mobile platform can move relative to the second mobile platform along the X direction, and the cotter pin locking device is mounted on the third mobile platform.

[0019] In some embodiments, the three-coordinate platform includes a second sub-platform installed on the second mobile platform, the second sub-platform includes a second sub-platform body and a fourth fixed slide rail, a fourth movable slide rail, a third screw rod and a third servo motor connected to the third screw rod installed on the second sub-platform body along the X direction; the nuclear power plant underwater cotter pin replacement equipment also includes a locking pin introduction device, which is installed on the fourth movable slide rail.

[0020] The implementation of the present invention has at least the following beneficial effects: since the locking pin introduction mechanism is installed on the arc-shaped track and can move along the track under the drive of the driving device; the locking pin introduction mechanism can install the locking pin in nuts set at different angles in the horizontal direction, avoiding unsafe factors in human operation, improving installation efficiency and the safety of replacing the cotter pin assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0022] Figure 1 is a schematic diagram of the three-dimensional structure of the cotter pin assembly in an assembled state in some embodiments of the present invention;

[0023] Figure 2 yes Figure 1 A cross-sectional view of the cotter pin assembly shown in an assembled state;

[0024] Figure 3 yes Figure 1 A schematic diagram of the three-dimensional structure of the split pin assembly shown in FIG.

[0025] Figure 4 is a front view of an underwater cotter pin replacement device for a nuclear power plant according to some embodiments of the present invention;

[0026] Figure 5 yes Figure 4 A schematic diagram of the three-dimensional structure of the underwater cotter pin replacement equipment of the nuclear power plant shown in another direction;

[0027] Figure 6 yes Figure 4 A schematic diagram of the three-dimensional structure of the underwater cotter pin replacement equipment of the nuclear power plant shown in another direction;

[0028] Figure 7 yes Figure 4 Schematic diagram of the three-dimensional structure of the underwater cotter pin replacement equipment of the nuclear power plant from another direction

[0029] Figure 8 yes Figure 4 Schematic diagram of the three-dimensional structure of the three-coordinate platform shown;

[0030] Figure 9 yes Figure 4 A schematic diagram of the three-dimensional structure of the three-coordinate platform in another direction;

[0031] Figure 10 yes Figure 4 A schematic diagram of the three-dimensional structure of the cotter pin locking device in the assembled state;

[0032] Figure 11 yes Figure 4 A schematic diagram of the three-dimensional structure of the cotter pin locking device in an exploded state;

[0033] Figure 12 yes Figure 4 A front view of the cotter pin locking device in the assembled state;

[0034] Figure 13 yes Figure 4 A cross-sectional view of the split pin locking device shown in an exploded state;

[0035] Figure 14 yes Figure 4 A schematic diagram of the three-dimensional structure of the locking pin introduction mechanism in the assembled state;

[0036] Figure 15 yes Figure 4 A cross-sectional view of the locking pin guide mechanism in the assembled state;

[0037] Figure 16 yes Figure 4 The shown figure is a cross-sectional view of the locking pin ejector cylinder in the exploded state. DETAILED DESCRIPTION

[0038] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0039] Figures 4 to 7 The invention shows a nuclear power plant underwater split pin replacement device 1 in some embodiments of the present invention, which can be used to replace the split pin assembly 100 (such as the split pin assembly 100 of the control rod guide cylinder of the nuclear power plant internal component) underwater. Figures 1 to 3As shown). In some embodiments, the underwater cotter pin replacement equipment 1 of a nuclear power plant may include a three-coordinate platform 10, a cotter pin locking device 20, a robotic arm 30, a locking pin introduction device 40, a welding tool 50, an underwater camera 60, and a control system (not shown). In some embodiments, the three-coordinate platform 10 can realize movement on the three coordinate axes of X, Y, and Z, and is used to move components connected to the three-coordinate platform 10 in three directions. The cotter pin locking device 20 is installed on the three-coordinate platform 10, and can be moved to the position where the cotter pin assembly 100 is set under the drive of the three-coordinate platform 10, and tighten the cotter pin assembly 100. The cotter pin locking device 20 can be used to remove damaged or install new cotter pin assemblies 100 for internal components of a nuclear power plant underwater, so as to achieve the purpose of overhauling the nuclear power plant reactor. It does not require manual operation, reduces operational risks, and makes the nuclear power plant reactor safer to a certain extent.

[0040] One end of the manipulator 30 is mounted on the three-coordinate platform 10, and the other end can be moved to a working position under the control of a control system. It can be used to clamp or adsorb components such as a cotter pin 101. The locking pin introduction device 40 is mounted on the three-coordinate platform 10 and is located above the cotter pin locking device 20. It can be used to introduce the locking pin 103 into the cotter pin assembly 100 to prevent relative rotation between the cotter pin assemblies 100. The welding tool 50 is mounted on the three-coordinate platform 10, and can be used to weld and fix the assembled cotter pin assembly 100. The control system can be used to control the three-coordinate platform 10, the cotter pin locking device 20, the manipulator 30 and other components, so that the underwater cotter pin replacement equipment 1 of the nuclear power plant can disassemble and replace the cotter pin assembly 100. The underwater camera 60 has a waterproof function and can be used to observe the installation status of the cotter pin assembly 100 underwater to determine whether it is installed in place.

[0041] See also Figure 8 and Figure 9 In some embodiments, the three-coordinate platform 10 may include a base 11, a first mobile platform 12, a second mobile platform 13, and a third mobile platform 14. The first mobile platform 12 is mounted parallel to the base 11 and can move back and forth in the Y direction relative to the base 11, so as to realize the movement of the components mounted on the first mobile platform 12 in the Y direction. The second mobile platform 13 is mounted on the first mobile platform 12 and can move back and forth in the Z direction relative to the first mobile platform 12, so as to realize the movement of the components mounted on the second mobile platform 13 in the Y and Z directions relative to the base 11. The third mobile platform 14 is mounted on the second mobile platform 13 and can move back and forth in the X direction relative to the second mobile platform 13, so as to realize the movement of the components mounted on the third mobile platform 14 in the X, Y, and Z directions relative to the base 11.

[0042] In some embodiments, the base 11 may include a base body 110, a first screw rod 111, a first servo motor 112, and a first fixed slide rail 113. The base body 110 is a rectangular flat plate that can be used to mount the first screw rod 111, the first servo motor 112, and the first fixed slide rail 113. The first servo motor 112 is connected to the first screw rod 111 and can provide power to the components of the first screw rod 111 to move along the first screw rod 111 through a gear set. The first fixed slide rail 113 and the first screw rod 111 are mounted parallel to the base body 110 in the Y direction to enable the first movable platform 12 mounted thereon to move in the Y direction.

[0043] In some embodiments, the first mobile platform 12 may include a first mobile platform body 120, a lifting motor 121, a second fixed slide rail 122 and a first movable slide rail 123. The first mobile platform body 120 is mounted on the first screw rod 111, so that it can move relative to the base 11 in the Y direction. The lifting motor 121 is vertically mounted on the first mobile platform body 120, which can be used to lift the second mobile platform 13 connected to the lifting motor 121. The second fixed slide rail 122 is vertically arranged, and its lifting direction is consistent with the lifting direction of the lifting motor 121. The second fixed slide rail 122 is mounted on the first mobile platform body 120, and can be used to enable the third mobile platform 13 to move in the Z direction relative to the first mobile platform 12. The first movable slide rail 123 is mounted on the lower surface of the first mobile platform body 120, and can cooperate with the first fixed slide rail 113 on the base 11 to realize the movement of the first mobile platform 12 in the Y direction.

[0044] The jacking motor 121 is vertically arranged and, in some embodiments, may include a jacking motor base 1212 and a jacking column 1211 connected to the second mobile platform 13. The jacking motor base 1212 is connected to the first mobile platform body 120 and can provide power for the extension and retraction of the jacking column 1211. The jacking column 1211 is mounted on the jacking motor base 1212 and can move up and down relative to the jacking motor base 1212. The upper end of the jacking column 1211 is connected to the second mobile platform 13, thereby enabling the second mobile platform 13 to move in the Z direction relative to the first mobile platform 12.

[0045] In some implementations, the second movable platform 13 may be comprised of multiple platforms arranged in parallel, including a main platform (not numbered), a first sub-platform 137, and a second sub-platform 138. The main platform is movably mounted on the first movable platform 12 in the Z direction. The first sub-platform 137 and the second sub-platform 138 are respectively connected to the main platform in parallel and vertically, and can be used to mount the locking pin guide device 40, the welding tool 50, and other components that need to be mounted.

[0046] In some embodiments, the main platform may include a second movable platform body 130 , a second movable slide rail 131 , a second screw rod 132 , a second servo motor 133 , a third fixed slide rail 134 , a first support column assembly 135 , and a second support column assembly 136 .

[0047] In some embodiments, the second mobile platform body 130 can be an inverted L-shaped plate, which includes a horizontal portion and a vertical portion. The second movable slide 131 is installed on the vertical portion of the second mobile platform body 130, and can cooperate with the vertically arranged second fixed slide 122, so that the second mobile platform 13 can move along the Z direction. The second screw rod 132 is installed on the horizontal portion of the second mobile platform body 130, and can be arranged along the X direction to provide power for the movement of the components connected to the second screw rod 132 along the X direction. The second servo motor 133 is connected to the second screw rod 132, and can provide power for the rotation of the second screw rod 132. The third fixed slide 134 is installed on the horizontal portion of the second mobile platform body 130 along the X direction, and can cooperate with the second screw rod 132, so that the third mobile platform 14 horizontally installed on the second mobile platform 13 can move along the X direction. In some embodiments, the underwater camera 60 is installed on the lower surface of the horizontal portion of the second mobile platform body 130. In some embodiments, the first support column assembly 135 may include a plurality of first support columns vertically mounted on the upper surface of the horizontal portion of the second movable platform body 130 and configured to connect to the second sub-platform 138. Specifically, one end of each of the first support columns is connected to the upper surface of the horizontal portion of the second movable platform body 130, and the other end is connected to the second sub-platform 138. In some embodiments, the second support column assembly 136 may include a plurality of second support columns vertically mounted on the lower surface of the horizontal portion of the second movable platform body 130 and configured to connect to the first sub-platform 137. Specifically, the upper ends of each of the second support columns are connected to the lower surface of the second movable platform body 130, and the lower ends are connected to the first sub-platform 137. In some embodiments, the first sub-platform 137 may be used to store welding tools 50. It will be appreciated that in addition to storing welding tools 50, the first sub-platform 137 may also be used to store other components, such as the cotter pin assembly 100.

[0048] In some embodiments, the second sub-platform 138 may include a second sub-platform body 1381, a third screw rod 1382, a third servo motor 1383, a fourth fixed rail 1384, and a fourth movable rail 1385. The second sub-platform body 1381 is a horizontally arranged plate connected to the main platform via a first support column assembly 135. Specifically, the first support column assembly 135 is connected to the lower surface of the second sub-platform body 1381. The third screw rod 1382 is mounted on the upper surface of the second sub-platform body 1381 along the X-direction. It can cooperate with the third servo motor 1383 connected to one end of the third screw rod 1382 to provide power for the locking pin guide device 40 connected to the second sub-platform 138 to move along the X-direction. The fourth fixed rail 1384 is mounted on the upper surface of the second sub-platform body 1381 along the X-direction, parallel to the third screw rod 1382. It can cooperate with the fourth movable rail 1385 to enable the fourth movable rail 1385 to move along the fourth fixed rail 1384. In some embodiments, the locking pin introduction device 40 is installed on the fourth movable slide rail 1385 and the third screw rod 1382, so that the locking pin introduction device 40 can move along the X, Y, and Z directions.

[0049] In some embodiments, the third mobile platform 14 may include a third mobile platform body 141 and a third movable rail 142 mounted on the third mobile platform body 141. In some embodiments, the third mobile platform body 141 may include a horizontal portion 1411 and a vertical portion 1412 connected to one end of the horizontal portion 1411. The vertical portion 1412 is formed by the horizontal portion 1411 extending downward along the Z direction and can be used to connect to the cotter pin locking device 20. The third movable rail 142 is mounted on the lower surface of the horizontal portion 1411 of the third mobile platform body 140 and can be used to cooperate with the third fixed rail 134 to enable the third mobile platform body 140 to move along the X direction relative to the second mobile platform 13.

[0050] In some embodiments, since the first mobile platform 12 can move in the Y direction and the second mobile platform 13 installed on the first mobile platform 12 can move in the Z direction, the cotter pin locking device 20 and the locking pin introduction device 40 that can move in the X direction relative to the second mobile platform 13 can, in some embodiments, move in the X, Y, and Z directions relative to the base 11 through the cooperation of the first servo motor 112, the lifting motor 121, the second servo motor 133, and the third servo motor 1383.

[0051] In some embodiments, the three-coordinate platform 10 may further include an encoder (not shown), which can be connected to the first servo motor 112, the lifting motor 121, the second servo motor 133 and the third servo motor 1383, so as to control the moving distance or the number of rotations of each component connected to the three-coordinate platform 10, so as to realize the control of each component connected to the three-coordinate platform 10.

[0052] See also Figures 10 to 13 In some embodiments, the cotter pin locking device 20 may include a locking assembly 21 and a clamping assembly 22 corresponding to the arrangement of the locking assembly 21. The locking assembly 21 can be used to fix the nut 102 and rotate it, and can tighten the cotter pin 101 and the nut 102 with a fixed torque; the clamping assembly 22 is located below the locking assembly 21 and is installed on the vertical portion 1412 of the third mobile platform body 141. It can be used to clamp the cotter pin 101 and rotatably connect it to the nut 102.

[0053] In some embodiments, the locking assembly 21 may include a locking head 211 and a first drive assembly (not numbered) connected to the locking head 211. The locking head 211 is connected to the first drive assembly and can cooperate with the nut 102 in the cotter pin assembly 100 to rotationally connect the nut 102 to the cotter pin 101. The first drive assembly is connected to the three-coordinate platform 10 and can be used to drive the locking head to lock the nut 102 and the cotter pin 101.

[0054] In some embodiments, the first drive assembly may include a locking head tightening device 212, a first torque drive motor 213, a connector 214, and a first torque sensor (not shown). The locking head tightening device 212 is connected to the locking head 211 and mounted on the connector 214. It is provided with a gear structure and can tighten the nut 102 and the cotter pin 101 under the drive of the first torque drive motor 213. The first torque drive motor 213 is mounted at another position on the connector 214. At this position, the first torque drive motor 213 can engage with the locking head tightening device 212 through the gear structure, thereby driving the locking head tightening device 212 to tighten the nut 102. The connector 214 is mounted on the third mobile platform 14 to achieve the connection between the locking assembly 21 and the third mobile platform 14.

[0055] In some embodiments, the locking head tightening device 212 may include a sector-shaped gear plate 2120, a guide wheel assembly 2121 that cooperates with the sector-shaped gear plate 2120, and a cover plate 2122. The locking head 211 is mounted at the center of the sector of the gear plate 2120, allowing the locking head 211 and the gear plate 2120 to be coaxially connected. In some embodiments, the gear plate 2120 may include a sector-shaped gear plate body 2123, an arc-shaped guide groove 2124 defined in the gear plate body 2123, and serrations 2125 disposed on the arc of the sector-shaped gear plate body 2123. In some embodiments, the guide grooves 2124 can be two arc-shaped grooves, coaxial with the sector of the gear plate body 2123. This allows the gear plate body 2123 to maintain a fixed axial position when rotating along the guide grooves 2124, thereby maintaining the position of the locking head 211, thereby ensuring smooth assembly of the nut 102 and the cotter pin 101. It is understood that the number of guide grooves 2124 can be three or more, in addition to two; all of the multiple guide grooves are coaxial with the sector of the gear plate body 2123. The guide wheel group 2121 is fixedly mounted on the connector 214 and can cooperate with the guide groove 2124. Specifically, the guide wheel group 2121 may include two groups of guide wheel mechanisms, which can respectively cooperate with the two arcs of the guide groove 2124. The axes of the two groups of guide wheels are in the same plane as the axis of the sector of the gear plate body 2123, so that when the gear plate 2120 rotates in cooperation with the guide wheel group 2121, the locking head 211 and the gear plate 2120 rotate coaxially and the position of the rotation axis is fixed.

[0056] Under the cooperation of the first torque drive motor 213 connected to the third mobile platform 14, the sector-shaped gear plate 2120 can rotate about its center, i.e., the position of the locking head 211, thereby rotating the nut 102. A cover plate 2122 is installed above the gear plate 2120 and can be connected to the guide wheel assembly 2121 to prevent the gear plate 2120 from being separated from the guide wheel assembly 2121.

[0057] In some embodiments, the first torque drive motor 213 may include a motor body 2130, a connecting shaft 2131, a bearing 2132, and a drive gear 2133. The connecting shaft 2131 is connected to the motor body 2130 and can be used to output the torque generated by the motor body 2130. The bearing 2132 is sleeved on the connecting shaft 2131 and can be used to assist the rotation of the connecting shaft 2131, making its rotation smoother. The bearing 2132 is also embedded in the connector 214 to achieve the connection between the first torque drive motor 213 and the connector 214. The drive gear 2133 is mounted on the connecting shaft and can be engaged with the gear plate 2120 to transmit the torque generated by the first torque drive motor 213 to the gear plate 2120, thereby achieving the tightening between the nut 102 and the cotter pin 101.

[0058] In some embodiments, the connector 214 may include a connecting seat 2141, a steering shaft 2142, a connecting cylinder 2143, a bearing seat 2144, and a flange 2145. The connecting seat 2141 is mounted on the horizontal portion 1411 of the third movable platform 14 via fasteners, allowing the connecting area 214 to be mounted on the three-coordinate platform 10 and move in the X, Y, and Z directions. In some embodiments, there are two steering shafts 2142, which are vertically mounted on the connecting seat 2141 and can cooperate with the guide wheel assembly 2121 to fix the position of the guide wheel assembly 2121, thereby allowing the locking head 211 mounted on the locking head tightening device 212 to rotate around the fixed axis. The connecting cylinder 2143 is a vertical cylindrical shape and is located on one side of the connecting seat 2141. In some embodiments, the connecting cylinder 2143 and the connecting seat 2141 are integrally formed or welded. The connecting tube 2143 can be used to accommodate the connecting shaft 2131 of the first torque drive motor 213, allowing it to rotate within the connecting tube 2143. A bearing seat 2144 is mounted on the upper end of the connecting tube 2143 to support the bearing 2132 and drive gear 2133 of the first torque drive motor 213. In some embodiments, the bearing 2132 and drive gear 2133 are both mounted on one end of the connecting shaft 2131 mounted within the connecting tube 2143 and can rotate under the drive of the motor body 2130 to output torque. A flange 2145 is provided at the bottom of the connecting tube and can be mounted on the upper surface of the motor body 2130 to secure the first torque drive motor 213 to the connector 214. In some embodiments, the first torque drive motor 213 is connected to the three-coordinate platform 10 via the flange 2145 on the connector 214.

[0059] In some embodiments, a first torque sensor is provided in the first torque drive motor 213, which can stop the torque output of the first torque drive motor 213 when the torque during tightening reaches a predetermined value, thereby enabling the cotter pin assembly 100 to be tightened at a preset fixed torque.

[0060] In some embodiments, the clamping assembly 22 may include a rotatable chuck 211 and a second drive assembly (not numbered) connected to the chuck 211. The chuck 211 is mounted on the output shaft of the second drive assembly and can rotate with the rotation of the second torque assembly. The chuck 211 can be used to clamp the cotter pin 101, so that the cotter pin 101 can be positioned in a vertical direction and can rotate along its axial direction to cooperate with the locking assembly 21 to tighten the cotter pin assembly 100.

[0061] In some embodiments, the second drive assembly may include a second torque drive motor 222, a second torque sensor (not shown) and an electric push cylinder 223. The second torque drive motor 222 is installed above the electric push cylinder 223, and can be used to tighten the cotter pin assembly 100 and make the notch below the cotter pin 101 present a certain angle. The second torque sensor has the same function as the first torque sensor, and both can ensure that the locking torque between the cotter pin 101 and the nut 102 is a set fixed value. The electric push cylinder 223 is located directly below the second torque drive motor 222, which can push the second torque drive motor 222 and the chuck 211 upward, and push the cotter pin 101 axially along the cotter pin 101, so that the cotter pin 101 is easier to screw into the nut 102, thereby improving the efficiency of tightening the cotter pin assembly 100.

[0062] In some embodiments, the chuck 211 may include a chuck seat 2210 and a clamping jaw structure (not numbered) mounted on the chuck seat to clamp the cotter pin 101. In some embodiments, the chuck structure may include a servo motor 2211, a gear set 2212, multiple ball screws 2213, multiple clamping jaws 2214, a protrusion 2215, multiple clamping jaw seats 2216, a transmission gear 2217, a chuck cover 2218, and a cover 2219. The servo motor 2211 may be connected to the gear set 2212 via a gear meshing with the gear set 2212, and the gear is mounted on the output shaft of the servo motor 2211. The servo motor 2211 can be locked for a long time and can continuously output torque through the gear set 2212 to keep the chuck 211 able to continuously clamp the cotter pin 101, thereby ensuring that the cotter pin 101 does not become eccentric during the tightening process. Gear set 2212 is connected to servo motor 2211 and can output the power of servo motor 2211 to ball screw 2213. Ball screw 2213 is coaxial with gear set 2212 and connected to clamping jaw 2214. Ball screw 2213 and clamping jaw 2214 are arranged in a one-to-one correspondence. The force generated by the rotation of ball screw 2213 can be transmitted horizontally along the axial direction of clamping jaw 2214 through the gear mechanism on clamping jaw 2214 to add torque 2214, allowing the plurality of clamping jaws 2214 to move centripetally. When the cotter pin 101 is clamped, the plurality of clamping jaws 2214 can cooperate with each other to clamp the cotter pin 101 from different directions on the side of the cotter pin 101, and the axial direction of the cotter pin 101 is aligned with the axis of the chuck 211, thereby facilitating the tightening of the cotter pin 101. Specifically, the servo motor 2211 drives the gear installed on its output shaft to rotate, and the gear transmits the torque to the ball screw 2213 coaxially arranged with the gear set 2212 through the gear set 2212. Under the action of the ball screw 2213, the majority of the jaws 2214 can move centrifugally or centrifugally, closing or opening relative to the protrusion 2215, thereby clamping or releasing the cotter pin 101.

[0063] In some embodiments, the number of ball screws 2213 and clamping jaws 2214 can be three. The three ball screws 2213 and clamping jaws 2214 are evenly distributed on the chuck 211, and the distance between two adjacent ball screws 2213 or clamping jaws 2214 is equal, thereby better clamping the cotter pin 101. It is understood that the number of ball screws 2213 and clamping jaws 2214 can be set to two, four, five, or six, etc., in addition to three, as long as the distance between two adjacent ball screws 2213 or clamping jaws is equal.

[0064] In some embodiments, the protrusion 2215 can be elongated and mounted on the chuck base 2210, located at the center of the plurality of ball screws 2213 and the clamping jaws 2214. It is understood that the protrusion 2215 can be integrally formed with the chuck base 2210 or connected to the chuck base 2210 by other means such as welding. When the cotter pin 101 is clamped in the chuck 211, the protrusion 2215 can engage with the notch at the bottom of the cotter pin 101, thereby allowing the cotter pin 101 to rotate with the chuck 211 and transmit the torque generated by the second torque drive motor 222. When the cotter pin locking device 20 is used in some embodiments, the robotic arm can first clamp the cotter pin 101 on the chuck 211, align the notch of the cotter pin 101 with the protrusion 2215 on the chuck 211, and then the clamping jaws 2214 can clamp the cotter pin 101 under the action of the servo motor 2211.

[0065] Multiple jaw mounts 2216 are mounted on the chuck base 2210 and serve to secure the jaws and transmission gear 2217. The transmission gear 2217 is sleeved onto the jaws 2214 and transmits torque generated when the ball screw 2213 rotates or when the servo motor 2211 stalls, enabling the multiple jaws 2214 to cooperate with each other and clamp the cotter pin 102. The chuck cover 2218 is a cylindrical cover structure with a circular hole in the center of its top surface. This serves to cover the chuck, giving it a certain aesthetic appeal and making the pull tray 221 waterproof. The circular hole on the top of the chuck 2218 allows for the cotter pin 102 to be extended. A cover 2219 is positioned around the chuck 221 and the second torque drive motor 222, providing the clamping assembly with a certain aesthetic appeal and a certain degree of waterproofing, facilitating underwater operation of the clamping assembly 22.

[0066] The second torque drive motor 222 can drive the chuck 211 to rotate, and may include a servo motor (not shown), an encoder (not shown) and a harmonic reducer (not shown) that cooperate with the servo motor. The servo motor can be used to rotate to transmit torque, so that the cotter pin assembly 100 can be tightened. In some embodiments, the encoder can be a multi-turn absolute encoder, which can be used to set a certain number of turns or angles of rotation. When the preset number of turns or angle is reached, the servo motor can immediately stop moving to achieve an opening angle and direction of 90° or 180° for the notch at the bottom of the cotter pin 101.

[0067] In some embodiments, the electric push cylinder 223 may include a servo motor (not shown) and a ball screw (not shown) connected to the servo motor. The servo motor can be locked for extended periods of time, ensuring that the cotter pin 101 maintains axial pressure during tightening with the nut 102, facilitating screwing. The ball screw is connected to the chuck 211, thereby continuously applying a certain positive pressure to the cotter pin 101.

[0068] In some embodiments, when using the cotter pin locking device 20, the three-axis platform 10 can drive the cotter pin locking device 20 downward so that the tightening head is inserted into the hexagonal hole of the nut 102. The electric push cylinder 223 pushes the chuck 211 upward, and the second torque drive motor 222 rotates synchronously until a preset torque is reached. The chuck 211 releases the clamping jaws 2214 and moves downward to disengage the cotter pin assembly 100, completing the tightening of the cotter pin assembly 100. In some embodiments, the cotter pin locking device 20 can be used to remove an old cotter pin assembly 100 and install a new cotter pin assembly 100.

[0069] like Figures 5 to 7 As shown, the robotic arm 30 may include a clamping tool 31, an adsorption tool 32 and a robotic arm body 33 in some embodiments. The robotic arm body 33 may be a six-axis robotic arm in some embodiments, one end of which is connected to the three-coordinate platform 10, and may be used to move the clamping tool 31 and the adsorption tool 32 to the desired position. The clamping tool 31 and the adsorption tool 32 are installed at the other end of the robotic arm body 33, and may provide the robotic arm 30 with a clamping function and an adsorption function, so as to facilitate the movement or fixation of the position of components such as the cotter pin 101 during underwater operation. In some embodiments, the clamping tool 31 may be a caliper device, specifically, a robotic arm caliper device having two clamping positions, one large and one small, so as to clamp components of different sizes.

[0070] See also Figure 14In some embodiments, the locking pin introduction device 40 may include a track 41, a drive device 42, and a locking pin introduction mechanism 43. The track 41 is arc-shaped and is horizontally arranged in the plane where the arc is located. Its lower end is connected to the three-coordinate platform 10. The locking pin introduction mechanism 43 is installed on the track 41, which can realize the movement and direction change of the locking pin introduction mechanism 43. The drive device 42 is connected to the track 41 and can be used to provide power for the movement of the locking pin introduction mechanism 43 on the track 41. In some embodiments, the drive device 42 can be a sliding drive motor or other device that can drive the locking pin introduction mechanism 43 to move on the track 41. The locking pin introduction mechanism 43 is installed on the track 41 and can move along the track 41; it can be used to introduce the locking pin 103 into the installation position on the nut 102.

[0071] In some embodiments, the arc-shaped track 41 has an effective travel of at least 120°. In this case, since the nut 102 is a hexagonal nut, the locking pin guide mechanism 43 mounted on the track 41 can ensure that the locking pin 103 can be guided into the installation position on the nut 102 after no more than 120° of rotation, regardless of the horizontal orientation of the nut 102.

[0072] See also Figure 15 In some embodiments, the locking pin introduction mechanism 43 may include a base 430, a locking pin ejection cylinder 431, a locking pin loading position 432, a guide channel 433, and a hexagonal head 434. The lower end of the base 430 is mounted on the track 41, which enables the locking pin introduction mechanism 43 to move on the track 41 so that the locking pin introduction device 40 can be positioned to a suitable position for the installation of the locking pin 103. The locking pin ejection cylinder 431 is horizontally mounted on the upper end of the base 430 and can be used to eject the locking pin 103 from the locking pin introduction mechanism 43, allowing the locking pin 103 to reach the installation position, thereby achieving installation of the locking pin 103. The locking pin loading position 432 can be used to load a new locking pin 103 to achieve repeated installation of the locking pin 103. In some embodiments, the locking pin loading position 432 can be installed with three or more locking pins 103, thereby enabling continuous installation of the locking pins 103 and improving assembly efficiency.

[0073] Guide channel 433 is connected to locking pin loading position 432. When locking pin 103 is guided forward by locking pin ejector cylinder 431, locking pin 103 passes through guide channel 433 and disengages from locking pin loading position 432. Guide channel 433 ensures that the orientation of locking pin 103 remains fixed during installation, thereby improving the success rate of locking pin 103 installation and avoiding undesirable situations such as failure to install locking pin 103 due to directional deviation, operational errors, and low efficiency. Hexagonal head 434 is used to connect to nut 102 and has a guide groove for locking pin 103 to pass through, thereby installing locking pin 103 on nut 102.

[0074] See also Figure 16 In some embodiments, the locking pin ejector cylinder 431 may include a lead screw 4311, a lead screw nut 4312, a lead screw nut seat 4313, a lead screw nut guide rod 4314, a push rod seat 4315, a push rod 4316, a cylinder body 4317, a push rod hole 4318, and a lead screw drive motor 4319. The lead screw 4311 is connected to the lead screw drive motor 4319 and can rotate under the drive of the lead screw drive motor 4319. The lead screw nut 4312 is mounted on the lead screw nut seat 4313 and is sleeved on the lead screw 4311. The lead screw nut 4312 can move along the lead screw 4311 when the lead screw 4311 rotates, thereby driving the push rod 4316 to push the locking pin 103 into the nut 102. Specifically, the lead screw 4311 rotates axially at a fixed position, and the lead screw nut 4312 does not rotate relative to the cylinder body 4317 , so the lead screw nut 4312 will be displaced axially along the lead screw 4311 .

[0075] Screw nut seat 4313 is sleeved onto screw nut guide rod 4314 and can be used to mount screw nut 4312. It prevents screw nut 4312 from rotating relative to cylinder body 4317, thereby allowing screw nut 4312 to move axially along screw 4311. Screw nut guide rod 4314 is fixed to cylinder body 4317 and can guide screw nut seat 4313. Push rod seat 4315 is hollow and rod-shaped, with one end connected to screw nut 4312 and the other end having a mounting position for push rod 4316 to be axially mounted therein. This push rod seat 4315 can move with screw nut 4312, thereby pushing push rod 4316. One end of cylinder 4317 is connected to a screw drive motor 4319, and the other end is provided with a push rod hole 4318. Push rod 4316 can extend through push rod hole 4318, thereby pushing locking pin 103 to be installed in nut 102. Screw drive motor 4319 is connected to screw rod 4311, which drives screw rod 4311 to rotate, thereby achieving movement of push rod 4316.

[0076] Replacing a cotter pin assembly 100 using the cotter pin replacement system 1 can be divided into two steps: removing the old cotter pin assembly and installing a new cotter pin assembly.

[0077] Removal of the old cotter pin assembly may, in some embodiments, include the following steps:

[0078] S1, the chuck 211 moves upward to the cotter pin 101 and clamps the cotter pin 101;

[0079] S2. Use a dismantling tool to destroy the connection between the cotter pin 101 and the nut 102 of the cotter pin assembly 100;

[0080] S3, using the robotic arm 30 to place the broken fragments of the cotter pin assembly 100 into a waste box;

[0081] S4. Use the clamping tool 31 and the adsorption tool 32 of the robot arm 30 to take the cotter pin 101 out of the chuck 211 and put it into a waste box.

[0082] Installation of a new cotter pin assembly may, in some embodiments, include the following steps:

[0083] S1. Use the clamping tool 31 and the adsorption tool 32 of the robot arm 30 to clamp a new nut 102 from the storage position of the nut 102 and place it in the installation position.

[0084] S2. Use the clamping tool 31 and the adsorption tool 32 of the robot arm 30 to clamp a new cotter pin 101 from the cotter pin storage position, and place it in the chuck 211 of the cotter pin locking device 20 to clamp it.

[0085] S3. The three-coordinate platform 10 is moved and the torque drive motor with a torque sensor is used to adjust the angle so that the locking head 211 is embedded in the nut 102. Then, the electric push cylinder 223 is pushed upward to push the cotter pin 101 into the nut 102.

[0086] S4. The torque drive motor starts to rotate. When the encoder reading reaches the threshold (set the fixed number of rotations and angles to ensure the direction of the petal opening at the stop position), it stops pushing up and rotating to ensure that the angle of the petal opening at the bottom pin body is 90° or 180°.

[0087] S5, the clamping claws in the chuck 211 are loosened, the electric push cylinder 223 descends, and the locking head 211 is pulled out from the nut 102.

[0088] S6. Return to the starting position of the platform and then use the suction cup on the robot arm 30 to take the locking block 104, put the locking block 104 into the nut 102, and make the downward protrusion of the locking block 104 match the groove at the top of the cotter pin 101.

[0089] S7. The locking head 211 in the cotter pin locking device 20 is calibrated to a position and pressed into the nut 102. After the chuck 211 clamps the cotter pin 101, the torque drive motor with a torque sensor of the locking head tightening device 212 tightens the upper nut 102 with a torque of 100 Nm; at this time, the nut 102 rotates without changing the angle of the opening of the bottom pin body of the cotter pin 101.

[0090] S8, the locking head 211 in the cotter pin locking device 20 is pulled out from the nut 102, the cotter pin locking device 20 is lowered to the bottom as a whole, the locking pin introduction device 40 is inserted into the nut 102, and then the locking pin ejection cylinder 431 inserts the locking pin 103 into the nut 102, and the locking pin introduction device 40 returns to its original position;

[0091] S9. The three-coordinate platform 10 moves as a whole to make room for the welding tool 50. Finally, the clamping tool 31 and the adsorption tool 32 of the robot arm 30 are used to take the welding tool 50 and weld the locking block 104 and the locking pin 103. After welding, the locking pin 103 cannot rotate relative to the locking block 104, thereby preventing the nut 102 and the cotter pin 101 from rotating relative to each other.

[0092] S10, putting the welding tool 50 back to its original position, completing the replacement.

[0093] It can be understood that the above technical features can be used in any combination without limitation.

[0094] The above embodiments only express specific implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several modifications and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A locking pin introduction device for underwater cotter pin replacement equipment in nuclear power plants; characterized in that: include: Track, in the shape of a circular arc; A locking pin introduction mechanism is installed on the track and can move along the track; as well as a driving device connected to the locking pin introduction mechanism, for driving the locking pin introduction mechanism to move on the track; The arc-shaped track has an effective travel of at least 120°; The locking pin introduction mechanism includes a locking pin ejection cylinder and a locking pin loading position connected to one end of the locking pin ejection cylinder, and the locking pin loading position can be loaded with at least one locking pin; The locking pin introduction mechanism includes a guide channel, and the guide channel is in communication with the locking pin loading position; The locking pin introduction mechanism includes a hexagonal head connected to one end of the guide channel in the guiding direction, the hexagonal head is provided with a guide groove, and the locking pin is installed on the nut through the guide groove; The locking pin ejection cylinder includes a drive motor, a lead screw connected to the drive motor, and a lead screw nut mounted on the lead screw, wherein the lead screw nut can move axially along the lead screw; The locking pin ejection electric cylinder includes a push rod seat connected to the lead screw nut and a push rod installed on the push rod seat along the axial direction of the lead screw, and the push rod is used to guide the locking pin into the nut.

2. The locking pin introduction device according to claim 1, characterized in that: The locking pin introduction mechanism includes a seat connected to the locking pin ejection cylinder, and the seat is installed on the track.

3. The locking pin introduction device according to claim 1, characterized in that: The locking pin ejection electric cylinder includes a cylinder body, a screw nut guide rod connected to the cylinder body along the axial direction of the screw, and a screw nut seat connected to the screw nut guide rod, and the screw nut is installed on the screw nut seat.

4. An underwater cotter pin replacement device for a nuclear power plant, characterized in that: It comprises the locking pin introduction device according to any one of claims 1 to 3, and also comprises a three-coordinate platform and a cotter pin tightening device, wherein the locking pin introduction device is installed on the three-coordinate platform.

5. The underwater cotter pin replacement device for a nuclear power plant according to claim 4, characterized in that: The three-coordinate platform includes a base and a first movable platform movably mounted on the base, wherein the first movable platform can move relative to the base along the Y direction.

6. The underwater cotter pin replacement device for a nuclear power plant according to claim 5, characterized in that: The three-coordinate platform includes a second mobile platform movably mounted on the first mobile platform, and the second mobile platform can move relative to the first mobile platform along the Z direction.

7. The underwater cotter pin replacement device for a nuclear power plant according to claim 6, characterized in that: The underwater cotter pin replacement equipment for a nuclear power plant includes a robotic arm, which is installed on the second mobile platform.

8. The underwater cotter pin replacement device for a nuclear power plant according to claim 6, characterized in that: The three-coordinate platform includes a third mobile platform movably mounted on the second mobile platform, the third mobile platform can move relative to the second mobile platform along the X direction, and the cotter pin tightening device is mounted on the third mobile platform.

9. The underwater cotter pin replacement device for a nuclear power plant according to claim 6, characterized in that: The three-coordinate platform includes a second sub-platform installed on the second mobile platform, the second sub-platform includes a second sub-platform body and a fourth fixed slide rail, a fourth movable slide rail, a third screw rod and a third servo motor connected to the third screw rod installed on the second sub-platform body along the X direction; the nuclear power plant underwater cotter pin replacement equipment also includes a locking pin introduction device, which is installed on the fourth movable slide rail.

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