Control rod driving mechanism and splitting nut assembly

Abstract

According to the control rod driving mechanism and the splitting nut assembly, when an armature support attracts a second armature, the abutting end on the second armature abuts against the bearing end on a split nut, the abutting end exerts abutting force on the bearing end, and the component, facing the radial direction of the split nut, of the abutting force enables sub-nuts to be close to each other in the radial direction of the sub-nuts; the split nut is closed, the corresponding split nut and the lead screw are matched with each other to form a ball screw structure, and when the split nut rotates, the lead screw can be driven to move in the axial direction of the lead screw, so that the insertion amount of the control rod entering the core pile is controlled. When the armature driving piece is powered off, the second armature is separated from the armature support, the sub-nuts can be separated from each other in the radial direction of the sub-nuts, the rolling piece can be separated from the screw rod spiral groove of the screw rod, the screw rod can fall at the moment, and emergency shutdown is achieved. Compared with the prior art that a connecting rod structure is adopted to control opening and closing of the split nut, the split nut is simpler and more reliable in structure.

Description

Technical Field

[0001] The present invention relates to the technical field of control rod drive mechanisms of nuclear power reactors, and more specifically to a control rod drive mechanism and a cracking nut assembly. Background Art

[0002] In some types of nuclear reactors, such as pressurized water reactors, the rate of nuclear reactions is controlled by the movement of control rods. The control rods include neutron absorbing material and are arranged to be inserted into the reactor core. The deeper the control rods are inserted into the core, the more neutrons are absorbed, and thus the more the nuclear reaction rate is reduced. The amount of insertion of the control rods is therefore controlled, thereby controlling the reactivity of the reactor.

[0003] In an emergency, the control rod needs to be fully inserted into the reactor to quickly stop the nuclear reaction. The control rod drive mechanism types used in the pressurized water reactors (i.e., pressurized water-moderated cooling reactors) currently in operation at home and abroad are mainly divided into three types, namely, rack and pinion type, lead screw roller nut type, and magnetic drive step type. Among them, the lead screw roller nut type is to control the axial movement of the lead screw by driving the nut through the cooperation of the lead screw, roller and nut, thereby controlling the insertion amount of the control rod into the reactor.

[0004] For example, the publication number CN105788668A discloses a control rod drive mechanism with a detachable nut drive, including a detachable nut component; the detachable nut component is composed of a detachable nut, a plurality of connecting rods, an armature, and a release spring and is sleeved in the motor pressure housing; wherein the two connecting rods are identical; the two identical connecting rods, a connecting rod for connecting the rotor sleeve, the armature and the detachable nut constitute a single-degree-of-freedom connecting rod mechanism with a parallelogram structure, and the position of the detachable nut is controlled by the up and down movement of the armature; the driving screw component is composed of a core rod, a driving screw, a positioning block, a rod drop spring and a guide block; wherein one end of the driving screw is connected to the control rod assembly. In this scheme, the detachable nut is used to rotate the driving screw to make a linear motion, so as to realize the insertion, extraction and position keeping functions of the control rod assembly under various working conditions of the reactor. When an emergency safety situation causes a power outage, the drive screw cannot move. The armature is then ejected and the armature pulls the detachable nut through the connecting rod, disengaging it from the drive screw. The drive screw then quickly pushes the control rod assembly into the core under the action of the rod drop spring.

[0005] However, in this solution, in an emergency, the nut can be separated by pulling the connecting rod to disengage it from the meshing state with the drive screw, thereby achieving rod drop. The connecting rod mechanism controls the nut to separate. On the one hand, the connecting rod mechanism has many degrees of freedom, and after long-term operation, the connecting rod structure will wear and become loose, making it impossible to accurately control the opening and closing position of the nut. In addition, there are many components and connection positions in the connecting rod structure, while the nut drive structure is relatively small in a small reactor. It is difficult to accurately arrange the various components in this space. In addition, after the connecting rod controls the nut to close, the connecting rod structure has poor self-locking properties for the nut. If a large axial force is applied to the screw, it is easy to cause the nut to open and the screw to fall out. Summary of the invention

[0006] The present invention provides a control rod driving mechanism and a cracking nut assembly. In the scheme, the structure of the control nut opening and closing is simpler and more reliable.

[0007] In order to achieve the above object, the technical solution provided by the present invention is:

[0008] A splitting nut assembly is used for connecting with a screw rod with a spiral screw thread groove on the outer side; it includes an opening and closing nut and a nut opening and closing drive assembly;

[0009] The split nut is used to be sleeved on the outer side of the screw rod, and a nut spiral groove is arranged inside the nut spiral groove, and a rolling element is arranged inside the nut spiral groove; the split nut is formed by a plurality of sub-nuts that can be moved and separated along the radial direction thereof;

[0010] The nut opening and closing drive assembly includes an armature support, a second armature and an armature drive member;

[0011] The armature support is arranged at one end of the split nut; one end of the second armature is arranged on the outside of the split nut, and the end is provided with a push end; a plurality of receiving ends are arranged on the outside of the split nut for cooperating with the push end; the armature drive member is arranged close to the armature support and / or the second armature;

[0012] When the armature drive is powered on, the armature support attracts the second armature to move it close to the split nut; during this process, the pushing end on the second armature pushes the receiving end on the split nut, so that the sub-nuts approach each other in the radial direction, so that the rolling element on the split nut can be connected with the screw thread groove of the screw; when the armature drive is powered off, the second armature is separated from the armature support, and the sub-nuts can be separated from each other in the radial direction, so that the rolling element can be separated from the screw thread groove of the screw.

[0013] As a further improvement, the outer side of the split nut protrudes to form a plurality of drive blocks, and the receiving end is arranged on the drive block; a plurality of drive plates corresponding to the drive blocks are arranged on the second armature, and the push end is arranged on the drive plate.

[0014] As a further improvement, the receiving end and the pushing end are both inclined.

[0015] As a further improvement, a second elastic member is nested on the inner side of the split nut along its circumference; when the armature drive is powered off, the second elastic member causes the sub-nuts to quickly separate from each other along their radial direction, so that the split nut is unfolded.

[0016] As a further improvement, a support is fixedly arranged on the armature support, the support is arranged around the outside of the opening and closing nut, and a plurality of nut guide rods are arranged on the inner side of the support, at least one nut guide rod is radially penetrated on one of the sub-nuts.

[0017] As a further improvement, it also includes a locking assembly, the locking assembly including a first armature and at least one locking body;

[0018] The first armature is arranged at one end of the armature support, at least one slider is connected to the first armature, and the locking body is arranged through the second armature;

[0019] When the armature drive is powered on, the armature support attracts the second armature to close the opening and closing nut, and at the same time attracts the first armature to drive the slider to push the locking body to move close to the armature support, so that one side of the locking body is embedded in the armature support, so that the opening and closing nut is locked in a closed state.

[0020] As a further improvement, the second armature is located between the armature support and the first armature, and the first armature is connected to the slider through a push rod; one side of the armature support is connected to an armature connecting rod, and one end of the armature connecting rod passes through the second armature and is slidingly connected to the first armature; one side of the second armature is connected to an armature guide shaft, and the armature guide shaft passes through the first armature and is slidingly connected relative to the first armature.

[0021] As a further improvement, a first elastic member is further arranged between the first armature and the second armature.

[0022] As a further improvement, the locking body is a ball bearing, and the sliding block is tiltedly arranged on a side close to the locking body.

[0023] The present invention also provides a control rod drive mechanism for controlling the insertion amount of the control rod into the core stack, comprising any one of the cracking nut assemblies and the lead screw,

[0024] A spiral screw thread groove is provided on the outer side of the screw rod; the screw rod is inserted into the split nut and arranged along the axial direction of the split nut, and the split nut can drive the screw rod to move along its axial direction when the split nut rotates;

[0025] When the armature drive is powered on, the sub-nuts approach each other in radial direction, and the rolling element on the opening and closing nut is connected with the screw thread groove of the screw rod; when the armature drive is powered off, the sub-nuts can be separated from each other in radial direction, so that the rolling element is separated from the screw thread groove of the screw rod.

[0026] The technical solution provided by the present invention has the following beneficial effects compared with the prior art: when the armature drive member is energized and operated, the armature support and the second armature have attractive magnetism, at which time the armature support attracts the second armature, and during the attraction process, the pushing end on the second armature pushes the receiving end on the split nut, and the pushing end applies a pushing force to the receiving end, and the component of the pushing force in the radial direction of the split nut causes each sub-nut to approach each other along its radial direction, and the split nut is closed, so that a partial structure of the rolling element on the split nut can be connected with the screw groove of the screw rod, so that the corresponding split nut and the screw rod cooperate with each other to form a ball screw structure, and when the split nut rotates, it can drive the screw rod to move along its axial direction, thereby controlling the insertion amount of the control rod into the core stack. When the armature drive is powered off, the attraction between the armature support and the second armature is eliminated, the second armature is separated from the armature support, and the sub-nuts can be separated from each other in the radial direction under the action of external force, so that the rolling element can be separated from the screw thread groove of the screw rod. At this time, the screw rod can fall under its own gravity, and the control rod is urgently dropped into the core with the screw rod to realize emergency shutdown. Compared with the prior art that uses a connecting rod structure to control the expansion and closing of the opening and closing nut, the structure of this solution is simpler and more reliable.

[0027] With regard to other technical problems that can be solved by a control rod drive mechanism and a cracking nut assembly of the present invention, other technical features included in the technical solution and the advantages brought by these technical features, further detailed description will be made in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A front view of the assembly structure of the split nut and the nut split drive assembly;

[0029] Figure 2 A stereoscopic diagram of the assembly structure of the opening and closing nut and the nut opening and closing drive assembly;

[0030] Figure 3 Another perspective view of the assembly structure of the opening and closing nut and the nut opening and closing drive assembly;

[0031] Figure 4It is an exploded schematic diagram of the assembly structure of the opening and closing nut and the nut opening and closing drive component;

[0032] Figure 5 It is an exploded schematic diagram of the assembly structure of the opening and closing nut and the nut opening and closing drive component;

[0033] Figure 6 It is a schematic diagram of the overall structure of the control rod drive mechanism;

[0034] Figure 7 for Figure 6 Schematic diagram of the AA section;

[0035] Figure 8 for Figure 7 The enlarged schematic diagram of point B in the middle;

[0036] Fig. 9 for Figure 7 The enlarged schematic diagram at C in the middle;

[0037] Fig.10 It is a schematic diagram of the connection state between the armature support and the first armature in the locked state.

[0038] Description of labels:

[0039] 1. Screw rod; 11. Screw rod spiral groove; 2. Housing; 3. Armature drive member;

[0040] 41. first armature; 411. push rod; 412. guide through hole; 413. countersunk hole;

[0041] 42, second armature; 421, driving plate; 4211, pushing end; 422, first through hole; 423, armature guide shaft; 424, slider; 425, first elastic member; 426, locking body; 427, armature locking baffle;

[0042] 43. armature support; 431. armature connecting rod; 432. support locking baffle;

[0043] 44, split nut; 441, driving block; 4410, receiving end; 442, nut guide hole; 443, nut spiral groove; 444, second elastic member;

[0044] 45. support; 451. support plate; 452. nut guide rod;

[0045] 46. ​​Support connection section;

[0046] 47. Rotate the bearing. DETAILED DESCRIPTION

[0047] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.

[0048] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0049] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. Moreover, in addition to being used to indicate orientation or positional relationships, some of the above terms may also be used to express other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present application can be understood according to the specific circumstances.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so as to describe the embodiments of the present application described herein.

[0051] The terms "installed", "set", "provided with", and "connected" used in this application should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0052] like Figure 6 , Figure 7 and Figure 8 As shown, the present invention provides a control rod drive structure, which is applied to a nuclear reactor to control the insertion amount of the control rod into the core. The drive structure controls the insertion amount of the control rod into the core. The deeper the control rod is inserted into the core, the more neutrons are absorbed, and thus the nuclear reaction rate is reduced. In an emergency, the control structure also needs to perform an emergency rod drop on the control rod so that the control rod is fully inserted into the core.

[0053] like Figure 1-5 As shown, the present invention also provides a splitting nut assembly, which is used to cooperate with a screw rod 1 with a spiral screw thread groove 11 on the outer side. Specifically, it includes an opening and closing nut 44 and a nut opening and closing drive assembly.

[0054] The opening and closing nut 44 is used to be sleeved on the outside of the screw rod 1, and a nut spiral groove 443 is arranged in the opening and closing nut 44, and a rolling element is arranged in the nut spiral groove 443. The opening and closing nut 44 is formed by a plurality of sub-nuts that can be separated by radial movement. The nut spiral groove 443 is intermittent, and each section is located on each sub-nut. Moreover, when the opening and closing nut 44 is connected with the screw rod 1, the nut spiral groove 443 corresponds to the position of the screw spiral groove 11, and one side of the rolling element is located in the nut spiral groove 443, and the other side is located in the screw spiral groove 11, thereby forming a ball screw structure, so that when the opening and closing nut 44 rotates, it can drive the screw rod 1 to move along its axial direction. Moreover, the screw rod 1 is arranged vertically.

[0055] Furthermore, the nut opening and closing drive assembly includes an armature support 43, a second armature 42 and an armature drive member 3. Specifically, the armature support 43 is arranged at one end of the opening and closing nut 44, one end of the second armature 42 is arranged around the outside of the opening and closing nut 44, and the end is provided with a push end 4211, the second armature 42 can move toward or away from the armature support 43, and a plurality of receiving ends 4410 are provided on the outside of the opening and closing nut 44 for cooperating with the push end 4211; the armature drive member 3 is arranged near the armature support 43 and the second armature 42. Specifically, when the armature drive 3 is powered on, the armature support 43 attracts the second armature 42 and moves it close to the opening and closing nut 44; during this process, the pushing end 4211 on the second armature 42 pushes the receiving end 4410 on the opening and closing nut 44, so that the sub-nuts approach each other in the radial direction, so that the part of the rolling element on the opening and closing nut 44 can be matched and connected with the screw spiral groove 11 of the screw 1; when the armature drive 3 is powered off, the second armature 42 is separated from the armature support 43, and the sub-nuts can be separated from each other in the radial direction, so that the rolling element can be separated from the screw spiral groove 11 of the screw 1.

[0056] In this solution, a driving machine is also provided to drive the nut opening and closing driving assembly to rotate, and the armature support 43 is fixedly provided relative to the driving machine. As a specific implementation, the armature driving member 3 is selected as an electromagnetic coil, for example, the armature driving member 3 is surrounded and arranged outside the armature support 43 and the second armature 42. In other cases, the armature driving member 3 can also be located outside the armature support 43, or outside the second armature 42. When the armature drive 3 is powered on, the armature support 43 and the second armature 42 have magnetism for attraction. At this time, the armature support 43 attracts the second armature 42. During the attraction process, the push end 4211 on the second armature 42 pushes the receiving end 4410 on the split nut 44. The push end 4211 applies a push force to the receiving end 4410. The component of the push force in the radial direction of the split nut 44 makes each sub-nut approach each other in its radial direction, and the split nut 44 is closed, so that the partial structure of the rolling element on the split nut 44 can be connected with the screw thread groove 11 of the screw 1. When the armature drive 3 is powered off, the attraction force between the armature support 43 and the second armature 42 is eliminated, the second armature 42 is separated from the armature support 43, and the sub-nuts can be separated from each other in their radial direction under the action of external force, so that the rolling element can be separated from the screw thread groove 11 of the screw 1.

[0057] It should be noted that the external force that separates the sub-nuts from each other along their radial direction may come from different situations.

[0058] Combination Figure 3 As shown, in one case, the inner side of the closure nut 44 is nested with the second elastic member 444 along its circumference; when the armature drive member 3 is powered off, the second elastic member 444 applies an elastic force to each sub-nut to separate the sub-nuts from each other, and while separating the sub-nuts from each other, the sub-nuts are also quickly separated from each other, so that the closure nut 44 is unfolded. Regarding the setting of the second elastic member 444, a groove can be opened on the inner side of the closure nut 44, and the second elastic member 444 is embedded in the groove. After the second elastic member 444 is embedded in the groove, the side of the second elastic member 444 cannot exceed the inner side of the closure nut 44, so as to avoid interference between the second elastic member 444 and the lead screw 1. In addition, when the second elastic member 444 is set, when the push end 4211 applies a push force to the receiving end 4410, it is also necessary to overcome the elastic force of the second elastic member 444, so that each sub-nut can be close to each other along its radial direction.

[0059] In another case, the second elastic member 444 may not be provided. In this case, when the armature drive member 3 is powered off, the attraction force between the armature support 43 and the second armature 42 is eliminated, and after the second armature 42 is separated from the armature support 43, the push end 4211 no longer applies a push force to the receiving end 4410, and the split nut 44 is in a loose state at this time, and the lead screw 1 falls under the action of gravity. During the falling process, the outer surface of the lead screw interferes with the rolling element, thereby being able to push the sub-nuts to separate from each other.

[0060] As a further improvement, combined Figure 3 , Figure 4 and Figure 5 As shown, the outer side of the split nut 44 protrudes to form a plurality of drive blocks 441, and the receiving end 4410 is arranged on the drive block 441. The second armature 42 is provided with a plurality of drive plates 421 corresponding to the drive blocks 441, and the push end 4211 is arranged on the drive plate 421, and the drive plate 421 surrounds the outer side of the split nut 44. The drive blocks 441 are arranged at intervals along the outer side of the split nut 44 in the circumferential direction, and the number and position of the drive plates 421 correspond to the drive blocks 441.

[0061] Preferably, the receiving end 4410 and the pushing end 4211 are both inclined. Figure 4 , the receiving end 4410 is arranged at the lower side of the driving block 441, and the pushing end 4211 is arranged at the upper side of the driving plate 421. The receiving end 4410 and the pushing end 4211 are both arranged obliquely, and the driving block 441 at the receiving end 4410 gradually becomes thicker from the lower end to the upper end. When the pushing end 4211 moves upward with the second armature 42, the inclined side surface of the pushing end 4211 moves upward along the inclined side surface of the receiving end 4410. When moving upward, the driving block 441 at the receiving end 4410 gradually becomes thicker from the lower end to the upper end, and the pushing end 4211 squeezes the driving block 441, and further squeezes the opening and closing nut 44, so that the sub-nuts are close to each other. The receiving end 4410 and the pushing end 4211 are both arranged obliquely, so that the pushing end 4211 is easier to move along the receiving end 4410, so that it is easier to push the sub-nuts close to each other.

[0062] Combination Figure 4 and Figure 5 As shown, a support 45 is also provided, and the armature support 43 is fixedly provided on the support 45. The support 45 is arranged around the outside of the closure nut 44, and specifically, the support 45 includes support plates 451 arranged at intervals, each support plate 451 is located outside the closure nut 44 and avoids the drive block 441.

[0063] As a further improvement, a plurality of nut guide rods 452 are arranged on the inner side of the support 45, and at least one nut guide rod 452 is radially penetrated on a sub-nut. As a preferred embodiment, the nut guide rod 452 is arranged on the inner side of the support plate 451, and two nut guide rods 452 are arranged on the inner side of each support plate 451, and the other end of the nut guide rod 452 is penetrated on the sub-nut. Each sub-nut has a corresponding nut guide hole 442 for the insertion of the nut guide rod 452. When the sub-nuts approach and separate from each other, the sub-nuts move along the nut guide rod 452, and the nut guide rod 452 guides the sub-nuts to prevent the sub-nuts from deflecting during the movement. In addition, the support plate 451 is arranged on the outer side of the opening and closing nut 44, and when the sub-nuts separate and move from each other, the maximum stroke of the outer side of the sub-nut moves to abut against the inner side of the support plate 451, and the support plate 451 limits the opening and closing nut 44. It should be noted that when the nut guide rod 452 cooperates with the nut guide hole 442 , the end of the nut guide rod 452 away from the support plate 451 cannot exceed the inner surface of the split nut 44 to avoid interference with the screw rod 1 .

[0064] As another embodiment, Figure 8 , Fig. 9 and Fig.10 As shown, a locking assembly is also included, and the locking assembly includes a first armature 41 and at least one movable locking body 426. For example, the locking body 426 can be set to 1, 2, or 3, etc. In this solution, the locking body 426 is set to 3.

[0065] Specifically, the first armature 41 is arranged at one end of the armature support 43, at least one slider 424 is connected to the first armature 41, and the locking body 426 is arranged through the second armature 42. When the armature drive member 3 is powered on, the armature support 43 attracts the second armature 42 to close the opening and closing nut 44, and at the same time, the first armature 41 is attracted to drive the slider 424 to push the locking body 426 to move close to the armature support 43, so that one side of the locking body 426 is embedded in the armature support 43, so that the opening and closing nut 44 is locked in a closed state. As a further improvement, the number and position of the sliders 424 correspond to the setting of the locking body 426. The slider 424 is located on the outer side of the driving plate 421 of the second armature 42, and the armature support 43 is also located on the inner side of the driving plate 421 of the second armature 42. When the first armature 41 is attracted, the first armature 41 drives the slider 424 to move, and when the slider 424 moves, it pushes the locking body 426 to move close to the armature support 43. A recessed space that can accommodate a partial structure of the locking body 426 is provided on the armature support 43. After the locking body 426 is pushed, the partial structure passes through the inner wall of the driving plate 421 and is embedded in the recessed space. At the same time, the side of the locking body 426 close to the slider 424 is close to the slider 424, and the locking body 426 is limited and locked by the slider 424.

[0066] As a further improvement, the second armature 42 is located between the armature support 43 and the first armature 41 , and the first armature 41 is connected to the slide block 424 via the push rod 411 .

[0067] Specifically, see Figure 4 In the embodiment, one side of the armature support 43 is connected to the armature connecting rod 431, and one end of the armature connecting rod 431 passes through the second armature 42 and is slidably connected to the first armature 41. In detail, the second armature 42 is provided with a first through hole 422, and the first armature 41 is provided with a counterbore 413. One end of the armature connecting rod 431 passes through the first through hole 422 and extends into the counterbore 413. The end of the armature connecting rod 431 is also provided with a limit baffle, and the size of the limit baffle is larger than the diameter of the first through hole 422, so that the armature connecting rod 431 can guide the movement of the second armature 42, and can also limit the second armature 42 through the limit baffle to prevent the second armature 42 from falling.

[0068] In addition, one side of the second armature 42 is connected to an armature guide shaft 423, and the armature guide shaft 423 passes through the first armature 41 and is slidably connected relative to the first armature 41. In detail, the first armature 41 is provided with a guide through hole 412, and the armature guide shaft 423 passes through the guide through hole 412, and the armature guide shaft 423 cooperates with the guide through hole 412 to guide the movement of the first armature 41.

[0069] Preferably, the locking body 426 is a ball bearing, and the slider 424 is tilted on one side close to the locking body 426. The locking body 426 is configured as a ball bearing so that it can move flexibly to avoid being stuck. The slider 424 is tilted on one side close to the locking body 426 to facilitate pushing the locking body 426.

[0070] Combination Figure 8 and Fig. 9 As shown, regarding the locking function of the locking body 426, it is also necessary to explain that, Fig. 9 As shown, and Fig. 9 The view orientation in FIG. is described. Located on the upper side of the locking body 426, the inner side of the drive plate 421 protrudes to form an armature locking baffle 427, and the outer side of the armature support 43 protrudes to form a support locking baffle 432. When the first armature 41 is attracted, the slider 424 moves to push one side of the locking body 426 to embed into the concave space outside the armature support 43. At this time, the armature locking baffle 427 and the support locking baffle 432 are closely together to form a state of mutual limitation. Because the first armature 41 is attracted, a part of the locking body 426 is embedded in the armature support 43, and a part of the structure is located in the driving plate 421 of the second armature 42. At the same time, the other side of the locking body 426 is closely abutted by the slider 424, so that the push end 4211 on the driving plate 421 is tightly against the receiving end 4410, so as to prevent the screw from moving under the external force when a large external force is suddenly applied to the screw, and the opening and closing nut 44 is stretched open.

[0071] When the armature drive member 3 is powered off, the attraction between the first armature 41 and the armature support 43 is eliminated, and the first armature 41 falls. A structure capable of limiting the position of the outer side of the drive plate 421 is provided on one side of the slider 424, and the slider 424 cooperates with the drive plate 421 to limit the first armature 41 to prevent the first armature 41 from falling off.

[0072] Regarding the whereabouts of the first armature 41, see Fig. 9 In addition, a first elastic member 425 can be arranged between the first armature 41 and the second armature 42, so that the first armature 41 can fall rapidly under the action of its own gravity and the elastic force of the first elastic member 425, driving the slider 424 to quickly release the resistance to the locking body 426, and at this time, the second armature 42 falls and drives the locking body 426 to leave the concave space outside the armature support 43, and at the same time, the pushing end 4211 on the driving plate 421 no longer pushes the receiving end 4410, and the opening and closing nut 44 is unfolded.

[0073] In this solution, in order to protect the split nut 44, a housing 2 is further provided. Specifically, the housing 2 is sleeved on the outer side of the armature driver 3. In order to further improve the locking effect, the outer sides of the drive plate 421 and the slider 424 can be arranged close to the inner side of the armature driver 3, and the armature driver 3 is used to apply radial force to the drive plate 421 and the slider 424, so as to further prevent the split nut 44 from being unfolded under sudden external force in the locked state.

[0074] Combination Figure 1 and Figure 8 As shown, the outer side of the support 45 is also sleeved with a rotating bearing 47. Specifically, the upper end of the support 45 has a support connecting section 46, and the rotating bearing 47 is sleeved on the support connecting section 46. The inner ring of the rotating bearing 47 is relatively fixed to the support connecting section 46. In one case, the support connecting section 46 is integrally formed with other parts of the support 45; in other cases, the support 45 can also be separately provided with other parts of the support 45, and fixedly connected by bolts or screws.

[0075] The present invention provides a control rod drive mechanism for controlling the insertion amount of the control rod into the core pile, specifically comprising the above-mentioned cracking nut assembly and a screw rod 1. The screw rod 1 is arranged vertically, and a spiral screw thread groove 11 is provided on the outer side of the screw rod 1; the screw rod 1 is inserted into the opening and closing nut 44 and arranged along the axial direction of the opening and closing nut 44. When the driving machine drives the opening and closing nut 44 to rotate, the screw rod 1 can be driven to move along its axial direction, thereby controlling the insertion amount of the control rod into the core pile.

[0076] In one case, the driving machine is a motor, and a gear is fixedly connected to the outer side of the outer ring of the rotating bearing 47, and the gear is drivingly connected to the output shaft of the motor, so that the opening and closing nut 44 is driven to rotate when the motor rotates.

[0077] When the armature drive 3 is powered on, the sub-nuts approach each other in the radial direction, and the rolling element on the closure nut 44 is connected with the screw thread groove 11 of the screw 1. The closure nut 44 and the screw 1 form a ball screw structure, and the closure nut 44 can drive the screw 1 to move when it rotates. In an emergency, the armature drive 3 is powered off, and the sub-nuts can be separated from each other in the radial direction, so that the rolling element is separated from the screw thread groove 11 of the screw 1. At this time, the screw 1 can fall under its own gravity, and the control rod is dropped into the core with the screw 1 to achieve an emergency shutdown.

[0078] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A splitting nut assembly, used for being connected with a screw (1) having a spiral screw thread groove (11) on the outer side; characterized in that: It includes an opening and closing nut (44) and a nut opening and closing drive assembly; The split nut (44) is used to be sleeved on the outer side of the screw rod (1), and a nut spiral groove (443) is arranged inside the nut spiral groove (443), and a rolling element is arranged inside the nut spiral groove (443); the split nut (44) is formed by a plurality of sub-nuts that can be moved and separated along the radial direction thereof; The nut opening and closing drive assembly comprises an armature support (43), a second armature (42) and an armature drive member (3); The armature support (43) is arranged at one end of the split nut (44); one end of the second armature (42) is arranged on the outside of the split nut (44), and a push end (4211) is arranged on the end; a plurality of receiving ends (4410) are arranged on the outside of the split nut (44) for cooperating with the push end (4211); the armature drive member (3) is arranged close to the armature support (43) and / or the second armature (42); When the armature drive (3) is powered on, the armature support (43) attracts the second armature (42) to move it closer to the opening and closing nut (44); during this process, the pushing end (4211) on the second armature (42) pushes the receiving end (4410) on the opening and closing nut (44), so that the sub-nuts approach each other in the radial direction, so that the rolling element on the opening and closing nut (44) can be connected with the screw thread groove (11) of the screw rod (1); when the armature drive (3) is powered off, the second armature (42) is separated from the armature support (43), and the sub-nuts can be separated from each other in the radial direction, so that the rolling element can be separated from the screw thread groove (11) of the screw rod (1).

2. The cracking nut assembly according to claim 1, characterized in that: The outer side of the split nut (44) protrudes to form a plurality of drive blocks (441), and the receiving end (4410) is arranged on the drive block (441); a plurality of drive plates (421) corresponding to the drive blocks (441) are arranged on the second armature (42), and the push end (4211) is arranged on the drive plate (421).

3. The split nut assembly according to claim 1 or 2, characterized in that: The receiving end (4410) and the pushing end (4211) are both arranged at an inclination.

4. The cracking nut assembly according to claim 1, characterized in that: A second elastic member (444) is nested on the inner side of the opening and closing nut (44) along its circumference; when the armature drive member (3) is powered off, the second elastic member (444) causes the sub-nuts to quickly separate from each other along their radial direction, so that the opening and closing nut (44) is unfolded.

5. The cracking nut assembly according to claim 4, characterized in that: A support (45) is fixedly arranged on the armature support (43), the support (45) is arranged around the outside of the opening and closing nut (44), and a plurality of nut guide rods (452) are arranged on the inside of the support (45), at least one nut guide rod (452) is radially penetrated on one of the sub-nuts.

6. The cracking nut assembly according to claim 1, characterized in that: Also included is a locking assembly, the locking assembly comprising a first armature (41) and at least one locking body (426); The first armature (41) is arranged at one end of the armature support (43), at least one slider (424) is connected to the first armature (41), and the locking body (426) is arranged through the second armature (42); When the armature drive member (3) is powered on, the armature support (43) attracts the second armature (42) to close the opening and closing nut (44), and at the same time attracts the first armature (41) to drive the slider (424) to push the locking body (426) to move closer to the armature support (43), so that one side of the locking body (426) is embedded in the armature support (43), so that the opening and closing nut (44) is locked in a closed state.

7. The cracking nut assembly according to claim 6, characterized in that: The second armature (42) is located between the armature support (43) and the first armature (41), and the first armature (41) is connected to the slider (424) via a push rod (411); one side of the armature support (43) is connected to an armature connecting rod (431), and one end of the armature connecting rod (431) passes through the second armature (42) and is slidably connected to the first armature (41); one side of the second armature (42) is connected to an armature guide shaft (423), and the armature guide shaft (423) passes through the first armature (41) and is slidably connected relative to the first armature (41).

8. The cracking nut assembly according to claim 6, characterized in that: A first elastic member (425) is also provided between the first armature (41) and the second armature (42).

9. The cracking nut assembly according to claim 6, characterized in that: The locking body (426) is a ball bearing, and the sliding block (424) is arranged at an angle close to a side of the locking body (426).

10. A control rod drive mechanism for controlling the insertion amount of a control rod into a core stack, characterized in that: comprising the splitting nut assembly and the screw rod (1) according to any one of claims 1 to 9, A spiral screw thread groove (11) is provided on the outer side of the screw rod (1); the screw rod (1) is inserted into the split nut (44) and is arranged axially along the split nut (44); when the split nut (44) rotates, the screw rod (1) can be driven to move along its axial direction; When the armature drive (3) is powered on, the sub-nuts approach each other in the radial direction, and the rolling element on the opening and closing nut (44) is connected with the screw thread groove (11) of the screw rod (1); when the armature drive (3) is powered off, the sub-nuts can be separated from each other in the radial direction, so that the rolling element is separated from the screw thread groove (11) of the screw rod (1).

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