The driving mechanism of a loading and unloading device

Abstract

The present invention belongs to the field of nuclear industry, and particularly relates to a driving mechanism of a charging and discharging device for grasping fuel assemblies in a pressure vessel of a reactor. The driving mechanism includes a support sleeve (1) internally provided with a feed screw assembly (2) and a connecting rod mechanism (3), and further includes a grasping sleeve (4) arranged outside the lower end of the support sleeve (1) through the connecting rod mechanism (3); the feed screw assembly (2) is used to drive the connecting rod mechanism (3) to achieve contraction or extension. When the connecting rod mechanism (3) is in a contracted state, the grasping sleeve (4) is coaxial with the support sleeve (1); when the connecting rod mechanism (3) is in an extended state, the grasping sleeve (4) is located on one side of the lower end of the support sleeve (1), and their axes are parallel. At this time, the lateral displacement of the grasping sleeve (4) is the distance between adjacent fuel assemblies in the pressure vessel. The present invention realizes grasping of fuel assemblies at adjacent positions through the expansion and contraction of the driving mechanism, reduces the time of charging and discharging, that is, shortens the reactor shutdown period.

Description

Technical Field

[0001] The present invention belongs to the field of nuclear industry, and particularly relates to a driving mechanism of a fuel handling device. Background Art

[0002] A fuel assembly is provided inside the pressure vessel of a nuclear power plant reactor. The fuel handling device is one of the key devices of the nuclear power plant fuel operating system, and its main function is to load and unload the fuel assembly during the initial loading and refueling of the reactor. In general nuclear power plants, the fuel handling device realizes the precise positioning of grasping the fuel assembly by controlling the large and small vehicles on the device.

[0003] If the top cover of the pressure vessel is not opened during refueling, the fuel handling device can only refuel through the fixed sleeve on the upper head of the pressure vessel. The position of the fixed sleeve on the top of the pressure vessel is fixed and the diameter is small. The operating space for refueling through the fixed sleeve is limited, and it is very difficult to grasp the fuel assemblies around the lower part of the fixed sleeve. Summary of the Invention

[0004] The purpose of the present invention is to provide a driving mechanism of a fuel handling device. Through the telescopic function of the driving mechanism, the fuel handling device can grasp the fuel assemblies at adjacent positions at a fixed position (i.e., the fuel assemblies at adjacent positions in the pressure vessel), thereby improving the loading and unloading efficiency of the fuel assemblies.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is a driving mechanism of a fuel handling device for grasping the fuel assemblies inside the pressure vessel of a reactor. The driving mechanism includes a support sleeve internally provided with a feed screw assembly and a link mechanism, and further includes a grasping sleeve disposed outside the lower end of the support sleeve through the link mechanism. The feed screw assembly is used to drive the link mechanism to contract or extend. When the link mechanism is in a contracted state, the grasping sleeve is coaxial with the support sleeve. When the link mechanism is in an extended state, the grasping sleeve is located on one side of the lower end of the support sleeve, and their axes are parallel. At this time, the lateral displacement of the grasping sleeve is the distance between the adjacent fuel assemblies inside the pressure vessel.

[0006] Further,

[0007] The outer shell of the support sleeve is a cylinder, and an opening is provided on one side of the cylinder. When the link mechanism is in an extended state, it can extend out of the cylinder through the opening, so that the grasping sleeve is located on one side of the lower end of the support sleeve;

[0008] On one side of the inner surface of the cylinder, there are a bracket and a sliding groove for arranging the feed screw assembly; the bracket includes a lead screw bracket, a bearing bracket, and a reducer bracket arranged in sequence from top to bottom. The lead screw bracket is close to the top end of the support sleeve, and the sliding groove is located between the lead screw bracket and the bearing bracket;

[0009] At the lower end of the cylinder, there is a bottom plate, and on the upper surface of the bottom plate, there is a connecting rod support block;

[0010] The bottom plate and the bracket are fixedly connected to the cylinder by bolts or welding.

[0011] Furthermore, the feed screw assembly includes a lead screw, and a moving nut, a collar, a single-direction thrust ball bearing, a bushing, a tightening nut, a reducer, and a motor arranged on the lead screw.

[0012] Furthermore, at the upper end of the lead screw, there is a retaining ring groove, and a retaining ring is used to axially fix the lead screw in the lead screw bracket. The threaded length of the upper part of the lead screw can meet the extension length of the connecting rod mechanism. There is a boss in the middle of the lead screw, and a tightening thread is provided below the boss; the outer shape of the lower end of the lead screw is machined to match the output end interface of the reducer.

[0013] Furthermore, there is a pair of single-direction thrust ball bearings, which are sleeved on the lead screw between the boss and the tightening thread through the cooperation of the bushing and the collar, fixed on the lead screw by the tightening nut and the tightening thread, and arranged in the bearing bracket. The single-direction thrust ball bearings are used to reduce the radial load on the lead screw.

[0014] Furthermore, the reducer is fixed on the reducer bracket by bolts. The input end of the reducer is connected to the motor, and the output end of the reducer is connected to the lower end of the lead screw, used to transmit the power of the motor to the lead screw, so as to drive the lead screw to rotate. The moving nut is threadedly engaged with the upper part of the lead screw, and can change the rotational motion of the lead screw into the vertical motion of the moving nut.

[0015] Furthermore, the connecting rod mechanism includes a connecting rod, a connecting rod bracket, and a positioning slider.

[0016] Furthermore,

[0017] The connecting rod includes a long connecting rod, a short connecting rod, and a balance connecting rod;

[0018] The upper end of the long connecting rod and the upper end of the balance connecting rod are connected to the connecting rod bracket by a pin shaft; the lower end of the long connecting rod is fixed to the upper end of the grasping sleeve;

[0019] The lower end of the long connecting rod and the lower end of the balance connecting rod are connected to the upper end of the grasping sleeve through a pin shaft;

[0020] The lower end of the short connecting rod is connected to the connecting rod support block of the bottom plate through a pin shaft, and the upper end of the short connecting rod is connected to the midpoint of the long connecting rod through a pin shaft.

[0021] Furthermore, the positioning slider, the moving nut are connected to the connecting rod bracket. One end of the positioning slider passes through the sliding slot of the cylinder to restrict the rotation of the moving nut, so that when the lead screw rotates, the moving nut drives the connecting rod bracket to move vertically up and down.

[0022] Furthermore, the lower end of the short connecting rod and the upper end of the long connecting rod are in the same vertical plane. The connecting rod mechanism can be contracted or extended through the vertical movement of the moving nut, and then the horizontal movement of the grasping sleeve position can be realized, so as to realize the grasping of the adjacent fuel assemblies in the pressure vessel by the grasping sleeve position.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. The present invention realizes the grasping of fuel assemblies at adjacent positions through the telescopic movement of the driving mechanism, reduces the time for loading and unloading fuel, that is, compresses the reactor shutdown period, and improves the economy.

[0025] 2. Without opening the top cover of the pressure vessel during refueling, the present invention conducts refueling through the fixed sleeve on the upper head of the pressure vessel, and can realize the loading and unloading of fuel assemblies at multiple positions at one time. This function can reduce the openings on the upper head of the pressure vessel and improve the safety of the reactor. Description of the Drawings

[0026] Figure 1 is a schematic diagram of the driving mechanism of a fuel loading and unloading device described in the specific embodiment of the present invention (when in the contracted state, the grasping sleeve 4 is coaxial with the support sleeve 1);

[0027] Figure 2 is a schematic diagram of the driving mechanism of a fuel loading and unloading device described in the specific embodiment of the present invention (when in the extended state, the grasping sleeve 4 is located on one side of the lower end of the support sleeve 1);

[0028] Figure 3 is a schematic diagram of the support sleeve 1 described in the specific embodiment of the present invention;

[0029] Figure 4 is a schematic diagram of the feed screw assembly 2 described in the specific embodiment of the present invention;

[0030] Figure 5 is a schematic diagram of the lead screw 13 described in the specific embodiment of the present invention;

[0031] Figure 6 is a schematic diagram of the link mechanism 3 described in the specific embodiment of the present invention;

[0032] Figure 7 is a schematic diagram of the link in the link mechanism 3 described in the specific embodiment of the present invention (in the retracted state);

[0033] Figure 8 is a schematic diagram of the link in the link mechanism 3 described in the specific embodiment of the present invention (in the extended state);

[0034] In the figure: 1 - support sleeve, 2 - feed screw assembly, 3 - link mechanism, 4 - grasping sleeve, 5 - cylinder, 6 - lead screw support, 7 - sliding groove, 8 - bearing support, 9 - reducer support, 10 - link support block, 11 - bottom plate, 12 - moving nut, 13 - lead screw, 14 - collar, 15 - single-direction thrust ball bearing, 16 - bushing, 17 - tightening nut, 18 - reducer, 19 - motor, 20 - boss, 21 - tightening thread, 22 - link bracket, 23 - positioning slider, 24 - long link, 25 - short link, 26 - balance link. Specific Embodiment

[0035] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] As Figure 1 , 2 shown, a driving mechanism of a loading and unloading device provided by the present invention is used to grasp the fuel assembly in the pressure vessel of the reactor. Among them, it includes a support sleeve 1 with a feed screw assembly 2 and a link mechanism 3 arranged inside, and further includes a grasping sleeve 4 arranged outside the lower end of the support sleeve 1 through the link mechanism 3; the feed screw assembly 2 is used to drive the link mechanism 3 to achieve contraction or extension. When the link mechanism 3 is in the retracted state, the grasping sleeve 4 is coaxial with the support sleeve 1, and the whole can pass through the fixed sleeve on the upper head of the pressure vessel; when the link mechanism 3 is in the extended state, the grasping sleeve 4 is located on one side of the lower end of the support sleeve 1, and their axes are parallel, and the grasping sleeve 4 is not coaxial with the support sleeve 1. At this time, the grasping sleeve 4 can grasp the fuel assembly at the adjacent position below the fixed sleeve inside the pressure vessel. At this time, the lateral displacement of the grasping sleeve 4 is the distance between adjacent fuel assemblies in the pressure vessel.

[0037] As Figure 3 shown, the outer shell of the support sleeve 1 is a cylinder 5. One side of the cylinder 5 is provided with an opening to leave space for the movement of the link mechanism 3. When the link mechanism 3 is in the extended state, it can extend from the opening to outside the cylinder 5, so that the grasping sleeve 4 is located on one side of the lower end of the support sleeve 1;

[0038] On one side of the inner surface of the cylinder 5, there are a bracket and a sliding groove 7 for arranging the feed screw assembly 2; the bracket includes a lead screw bracket 6, a bearing bracket 8 and a reducer bracket 9 arranged in sequence from top to bottom. The lead screw bracket 6 is close to the top end of the support sleeve 1, and the sliding groove 7 is located between the lead screw bracket 6 and the bearing bracket 8;

[0039] At the lower end of the cylinder 5, there is a bottom plate 11, and on the upper surface of the bottom plate 11, there is a connecting rod support block 10;

[0040] The bottom plate 11 and the bracket are fixedly connected to the cylinder 5 by bolts or welding.

[0041] As Figure 4 shown, the feed screw assembly 2 includes a lead screw 13 and a moving nut 12, a collar 14, a single-direction thrust ball bearing 15, a bushing 16, a tightening nut 17, a reducer 18 and a motor 19 arranged on the lead screw 13.

[0042] As Figure 5 shown, at the upper end of the lead screw 13, there is a retaining ring groove, and a retaining ring is used to axially fix the lead screw 13 in the lead screw bracket 6. The thread length of the upper part of the lead screw 13 can meet the extension length of the connecting rod mechanism 3. There is a boss 20 in the middle of the lead screw 13, and a tightening thread 21 is arranged below the boss 20; the outer shape of the lower end of the lead screw 13 is machined to fit the output end interface of the reducer 18.

[0043] There is a pair of single-direction thrust ball bearings 15, which are sleeved on the lead screw 13 between the boss 20 and the tightening thread 21 through the cooperation of the bushing 16 and the collar 14, fixed on the lead screw 13 through the tightening nut 17 and the tightening thread 21, and arranged in the bearing bracket 8. The single-direction thrust ball bearings 15 are used to reduce the radial load on the lead screw 13.

[0044] The reducer 18 is fixed on the reducer bracket 9 by bolts. The input end of the reducer 18 is connected to the motor 19, and the output end of the reducer 18 is connected to the lower end of the lead screw 13, which is used to transmit the power of the motor 19 to the lead screw 13, so as to drive the lead screw 13 to rotate. The moving nut 12 is in threaded cooperation with the upper part of the lead screw 13, and can change the rotational motion of the lead screw 13 into the vertical motion of the moving nut 12.

[0045] As Figure 6 shown, the connecting rod mechanism 3 includes a connecting rod, a connecting rod bracket 22 and a positioning slider 23.

[0046] As Figure 7 、 8 shown, the connecting rod includes a long connecting rod 24, a short connecting rod 25 and a balance connecting rod 26;

[0047] The upper ends of the long connecting rod 24 and the balance connecting rod 26 are connected to the connecting rod bracket 22 through a pin shaft (rotatable); the lower end of the long connecting rod 24 is fixed to the upper end of the grasping sleeve 4;

[0048] The lower end of the long connecting rod 24 and the lower end of the balance connecting rod 26 are connected to the upper end of the grasping sleeve 4 through a pin shaft (rotatable).

[0049] The lower end of the short connecting rod 25 is connected to the connecting rod support block 10 of the bottom plate 11 through a pin shaft (rotatable), and the upper end of the short connecting rod 25 is connected to the midpoint of the long connecting rod 24 through a pin shaft (rotatable).

[0050] The positioning slider 23, the moving nut 12 and the connecting rod bracket 22 are connected. One end of the positioning slider 23 passes through the sliding groove 7 of the cylinder 5 to restrict the rotation of the moving nut 12, so that when the lead screw 13 rotates, the moving nut 12 drives the connecting rod bracket 22 (i.e., one end of the long connecting rod 24 and the balance connecting rod 26) to move vertically up and down.

[0051] The lower end of the short connecting rod 25 and the upper end of the long connecting rod 24 are in the same vertical plane. The connecting rod mechanism 3 can be contracted or extended through the vertical movement of the moving nut 12, and then the horizontal movement of the grasping sleeve 4 can be realized, so as to realize the grasping of adjacent fuel assemblies in the pressure vessel by the grasping sleeve 4.

[0052] The device described in the present invention is not limited to the embodiments described in the specific embodiments. Those skilled in the art can obtain other embodiments according to the technical solutions of the present invention, which also belong to the scope of the technical innovation of the present invention.

Claims

1. A driving mechanism of a loading and unloading device, which is used to grasp the fuel assembly in the pressure vessel of the reactor, is characterized in that: It includes a support sleeve (1) internally provided with a feed screw assembly (2) and a link mechanism (3), and further includes a grasping sleeve (4) arranged outside the lower end of the support sleeve (1) through the link mechanism (3); the feed screw assembly (2) is used to drive the link mechanism (3) to achieve contraction or extension. When the link mechanism (3) is in a contracted state, the grasping sleeve (4) is coaxial with the support sleeve (1); when the link mechanism (3) is in an extended state, the grasping sleeve (4) is located on one side of the lower end of the support sleeve (1), and their axes are parallel. At this time, the lateral displacement of the grasping sleeve (4) is the distance between adjacent fuel assemblies in the pressure vessel. The outer shell of the support sleeve (1) is a cylinder (5). One side of the cylinder (5) is provided with an opening through which the link mechanism (3) can extend outside the cylinder (5) when in an extended state, so that the grasping sleeve (4) is located on one side of the lower end of the support sleeve (1). One side of the inner surface of the cylinder (5) is provided with a bracket and a sliding groove (7) for arranging the feed screw assembly (2); the bracket includes a lead screw bracket (6), a bearing bracket (8), and a reducer bracket (9) arranged in sequence from top to bottom. The lead screw bracket (6) is close to the top end of the support sleeve (1), and the sliding groove (7) is located between the lead screw bracket (6) and the bearing bracket (8). The lower end of the cylinder (5) is provided with a bottom plate (11), and a link support block (10) is provided on the upper surface of the bottom plate (11). The bottom plate (11) and the bracket are fixedly connected to the cylinder (5) by bolts or welding. The feed screw assembly (2) includes a lead screw (13) and a moving nut (12), a collar (14), a single-direction thrust ball bearing (15), a bushing (16), a tightening nut (17), a reducer (18), and a motor (19) arranged on the lead screw (13). A retaining ring groove is provided at the upper end of the lead screw (13), and a retaining ring is used to axially fix the lead screw (13) in the lead screw bracket (6). The threaded length of the upper part of the lead screw (13) can meet the extended length of the link mechanism (3). A boss (20) is provided in the middle of the lead screw (13), and a tightening thread (21) is provided below the boss (20); the outer shape of the lower end of the lead screw (13) is machined to match the output end interface of the reducer (18). There are a pair of single-direction thrust ball bearings (15), which are sleeved on the lead screw (13) between the boss (20) and the tightening thread (21) through the cooperation of the bushing (16) and the collar (14), fixed on the lead screw (13) by the tightening nut (17) and the tightening thread (21), and arranged in the bearing bracket (8). The single-direction thrust ball bearings (15) are used to reduce the radial load on the lead screw (13).

2. The drive mechanism of a loading and unloading device as claimed in claim 1, characterized in that: The speed reducer (18) is fixed on the speed reducer bracket (9) by bolts. The input end of the speed reducer (18) is connected to the motor (19), and the output end of the speed reducer (18) is connected to the lower end of the lead screw (13) for transmitting the power of the motor (19) to the lead screw (13), thereby driving the lead screw (13) to rotate. The moving nut (12) is in threaded engagement with the upper part of the lead screw (13) and can convert the rotational motion of the lead screw (13) into the vertical motion of the moving nut (12).

3. The drive mechanism of a loading and unloading device according to claim 2, characterized in that: The link mechanism (3) includes a link, a link bracket (22), and a positioning slider (23).

4. The drive mechanism of a loading and unloading device according to claim 3, characterized in that: The link includes a long link (24), a short link (25), and a balance link (26); The upper end of the long link (24) and the upper end of the balance link (26) are connected to the link bracket (22) by a pin shaft; the lower end of the long link (24) is fixed to the upper end of the grasping sleeve (4). The lower end of the long link (24) and the lower end of the balance link (26) are connected to the upper end of the grasping sleeve (4) by a pin shaft; The lower end of the short link (25) is connected to the link support block (10) of the bottom plate (11) by a pin shaft, and the upper end of the short link (25) is connected to the midpoint of the long link (24) by a pin shaft.

5. The drive mechanism of a loading and unloading device according to claim 4, characterized in that: The positioning slider (23), the moving nut (12) are connected to the link bracket (22). One end of the positioning slider (23) passes through the sliding groove (7) of the cylinder (5) to restrict the rotation of the moving nut (12), so that when the lead screw (13) rotates, the moving nut (12) drives the link bracket (22) to move vertically up and down.

6. The drive mechanism of a loading and unloading device according to claim 5, characterized in that: The lower end of the short link (25) and the upper end of the long link (24) are in the same vertical plane. The link mechanism (3) can be contracted or extended through the vertical motion of the moving nut (12), and then the horizontal motion of the grasping sleeve (4) can be realized, so as to realize the grasping of the adjacent fuel assemblies in the pressure vessel by the grasping sleeve (4).

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