CN112413145A

CN112413145A - Oblique butt-clamping butterfly valve

Info

Publication number: CN112413145A
Application number: CN202011501920.3A
Authority: CN
Inventors: 许辉斗
Original assignee: Jiulong Valve Co ltd
Current assignee: Jiulong Valve Co ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-02-26

Abstract

The invention discloses an inclined oppositely-clamping butterfly valve, which comprises a clamping frame, wherein a first hand wheel is arranged outside the clamping frame, one end of the first hand wheel extends to the inside of the clamping frame and is fixedly connected with a first threaded rod, one end of the first threaded rod, which is far away from the first hand wheel, is tightly attached with a sliding inclined block in sliding connection with the inner wall of the clamping frame, the inclined surface of the sliding inclined block is tightly attached with a telescopic column, one end of the telescopic column, which is far away from the sliding inclined block, is welded with a moving plate, and the top end of the moving plate is slidably connected with a moving column. The inclined plane of the sliding inclined block drives the telescopic column to slide along the inner wall of the clamping frame, so that the telescopic column is controlled to drive the moving plate to move conveniently.

Description

Oblique butt-clamping butterfly valve

Technical Field

The invention relates to the technical field of butt-clamping butterfly valves, in particular to an inclined butt-clamping butterfly valve.

Background

The butterfly plate of the butt-clamping butterfly valve is arranged in the diameter direction of a pipeline, the disc-shaped butterfly plate rotates around an axis in a cylindrical channel of a valve body of the butterfly valve, the rotation angle is 0-90 degrees, when the disc-shaped butterfly plate rotates to 90 degrees, the valve is in a full-open state, the valve is generally horizontally arranged, the butt-clamping butterfly valve is simple in structure, small in size and light in weight, only comprises a few parts, can be quickly opened and closed only by rotating 90 degrees, is simple to operate, and has good fluid control characteristics, when the butterfly valve is in a fully-opened position, the thickness of the butterfly plate is the only resistance when a medium flows through the valve body, so that pressure drop generated by the valve is small, and the butterfly valve has good flow control characteristics.

However, the problem of pipeline leakage during the operation of the existing butt-clamping butterfly valve is solved, so that the butterfly valve cannot work and cannot meet the requirements of people, and therefore the oblique butt-clamping butterfly valve is provided.

Disclosure of Invention

The invention aims to provide an inclined butt-clamping butterfly valve to solve the problem of pipeline leakage in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides an oblique type is to pressing from both sides butterfly valve, includes and presss from both sides tight frame, the outside of pressing from both sides tight frame is provided with first hand wheel, and the one end of first hand wheel extends to the first threaded rod of the inside fixedly connected with of pressing from both sides tight frame, the one end that first hand wheel was kept away from to first threaded rod closely laminates and has the slip sloping block with the inner wall sliding connection who presss from both sides tight frame, and the inclined plane of slip sloping block closely laminates and has flexible post, the one end welding that slip sloping block was kept away from to flexible post has the motion plate, and the top sliding connection of motion plate has the removal post, the sliding hole groove has been seted up with the position of being connected of motion plate to the removal post, and the top that the sliding hole groove is located the removal post welds and has the clamp ring, the inner wall of clamp ring closely laminates and has pipeline.

Preferably, the sliding inclined block forms a telescopic structure through the first threaded rod and the clamping frame, the telescopic length of the sliding inclined block is equal to the length of the moving plate, the inclined angle of the inclined plane of the sliding inclined block is 30 degrees, and the width of the sliding inclined block is equal to the height of the sliding hole groove.

Preferably, the movable plate forms a telescopic structure through the sliding inclined block and the clamping frame, the telescopic length of the movable plate is equal to the width of the sliding inclined block, two sets of sliding hole grooves are arranged, the two sets of sliding hole grooves are symmetrical relative to the movable plate, and the inclination angle of the sliding hole grooves is 45 degrees.

Preferably, the clamping rings are arranged in two groups, the positions of the clamping rings are distributed symmetrically about the moving plate, the clamping rings are closely attached to the conveying pipeline, and the diameter of the conveying pipeline is equal to that of the valve body.

Preferably, the valve body comprises a backrest, a first sealing ring, a limiting column, a fixing lug ring, a butt-clamp bolt, a valve core, a second sealing ring, a rotating cylinder, a third sealing ring, a reinforcing rod and a rotating shaft, wherein the inner wall of the valve body is attached with the backrest tightly attached to the conveying pipeline, the first sealing ring is arranged at the connecting part of the backrest and the conveying pipeline, the limiting column penetrating through the backrest is arranged at the connecting part of the first sealing ring and the backrest, the fixing lug ring is welded on the outer wall of the valve body, the butt-clamp bolt fixedly connected with the conveying pipeline penetrates through the fixing lug ring, the valve core is tightly attached to the inner wall of the backrest, the second sealing ring is arranged at the connecting part of the valve core and the backrest, the rotating cylinder is welded inside the valve core, the third sealing ring is arranged at the inner wall of the valve body at the two ends of the rotating cylinder, the reinforcing rod is welded at the connecting part, and a rotating shaft fixedly connected with the working box penetrates through the inner wall of the rotating cylinder.

Preferably, the limiting columns are provided with six groups, the six groups of limiting columns are distributed in an equiangular circumference mode by taking the central axis of the valve body as the center, the first sealing ring is tightly attached to the backrest, the valve core is tightly attached to the backrest through the second sealing ring, the diameter of the second sealing ring is 0.9 times of that of the valve core, and the rotating cylinder is tightly attached to the valve body through the third sealing ring.

Preferably, the reinforcing rods are arranged in two groups, the two groups of reinforcing rods are symmetrical with respect to the rotating cylinder, the valve core is eccentric, the eccentric height of the valve core is equal to the thickness of the reinforcing rods, a groove is formed in the rotating cylinder, and the groove of the rotating cylinder is matched with the protruding block of the rotating shaft.

Preferably, the workbin includes second hand wheel, second threaded rod, sliding block, dwang and rolling disc, the outside of workbin is provided with the second hand wheel, and the one end of second hand wheel extends to the inside welding of workbin has the second threaded rod, the outer wall threaded connection of second threaded rod has the sliding block, and the bottom of sliding block has connect the dwang soon, the one end and the axis of rotation fixed connection's rolling disc of sliding block are kept away from to the dwang.

Preferably, the axis of rolling disc coincides with the axis of rotation mutually, the rolling disc passes through to constitute revolution mechanic between dwang and the work box, and the turned angle of rolling disc is 90, the second threaded rod is provided with two sets ofly, and the position relation of two sets of second threaded rods is symmetrical for regarding the rolling disc, the screw thread opposite direction of two sets of second threaded rods, and the thread length of second threaded rod is 0.7 times of rolling disc length.

Compared with the prior art, the invention has the beneficial effects that:

1. this oblique type is to pressing from both sides butterfly valve, through setting up the slip sloping block, in pressing from both sides tight frame, rotates first wheel and drives first threaded rod and rotate, and first threaded rod drives the slip sloping block and slides along pressing from both sides tight frame inner wall, and the flexible length of slip sloping block equals with the length of motion plate, and the inclined plane inclination of slip sloping block is 30, and the inclined plane of slip sloping block drives flexible post and slides along pressing from both sides tight frame inner wall, is convenient for control flexible post drive motion plate motion.

2. This oblique type is to pressing from both sides butterfly valve, through setting up the sliding hole groove, in pressing from both sides tight frame, flexible post motion drives the motion plate motion, the flexible length of motion plate equals with the width of slip sloping block, the motion plate motion drives the sliding hole groove motion, the sliding hole groove is provided with two sets ofly, and the sliding hole groove angle of inclination is 45, the sliding hole groove drives and removes the post motion, it drives the clamp ring motion to remove the post, the clamp ring stabilizes the butt clamp operation with pipeline and valve body, reduce the problem that leads to the leakage because of pipeline vibration.

3. This oblique type butt clamp butterfly valve, through setting up the valve body, in the valve body, the anchor strut is provided with two sets ofly, the anchor strut is connected as an organic whole with the case, and the case is eccentric form, the eccentric height of case equals with the thickness of anchor strut, the compressive strength of valve body has been improved, and the case passes through the second sealing washer and closely laminates with the back, the sealing connection of case with the back has been realized, and it closely laminates with the valve body through the third sealing washer to rotate a section of thick bamboo, the sealing connection of a section of thick bamboo and valve body has been realized rotating, and pipeline closely laminates through first sealing washer and back, realize pipeline and the sealing connection of valve body, and the case sets up to eccentric form.

4. This oblique type is to pressing from both sides butterfly valve, through setting up the rolling disc, in the work box, it drives the second threaded rod rotation to rotate the second hand wheel, the second threaded rod is provided with two sets ofly, and the screw thread opposite direction of two sets of second threaded rods, and the screw thread length of second threaded rod passes through the screw thread for 0.7 times second threaded rod of rolling rod length and drives the sliding block motion, the sliding block drives the dwang motion, the dwang drives the carousel and rotates, the turned angle of rolling disc is 90, the rolling disc passes through the axis of rotation and drives the case rotation, the realization is to the operation that opens and shuts of valve body.

Drawings

FIG. 1 is a schematic front view of the present invention;

FIG. 2 is a schematic view of the internal structure of the clamping frame of the present invention;

FIG. 3 is a schematic view of a valve body connection structure according to the present invention;

FIG. 4 is a schematic view of the butt-clamp connection structure of the present invention;

FIG. 5 is a schematic view of the valve body structure of the present invention;

FIG. 6 is a schematic view of the construction of the work box of the present invention;

FIG. 7 is a schematic diagram of a front view of the valve cartridge of the present invention;

fig. 8 is a rear view structural schematic diagram of the valve core of the invention.

In the figure: 1. a clamping frame; 2. a first hand wheel; 3. a first threaded rod; 4. a sliding swash block; 5. a telescopic column; 6. a motion plate; 7. moving the column; 8. a sliding hole groove; 9. a clamping ring; 10. a delivery conduit; 11. a valve body; 1101. a backrest; 1102. a first seal ring; 1103. a limiting column; 1104. fixing the earrings; 1105. oppositely clamping the bolts; 1106. a valve core; 1107. a second seal ring; 1108. a rotating cylinder; 1109. a third seal ring; 1110. a reinforcing rod; 1111. a rotating shaft; 12. a work box; 1201. a second hand wheel; 1202. a second threaded rod; 1203. a slider; 1204. rotating the rod; 1205. and (6) rotating the disc.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 8, in an embodiment of the present invention, an inclined type butt-clamping butterfly valve includes a clamping frame 1, a first hand wheel 2 is disposed outside the clamping frame 1, one end of the first hand wheel 2 extends to an inside of the clamping frame 1 and is fixedly connected with a first threaded rod 3, one end of the first threaded rod 3, which is far away from the first hand wheel 2, is closely attached with a sliding inclined block 4, which is slidably connected with an inner wall of the clamping frame 1, an inclined surface of the sliding inclined block 4 is closely attached with a telescopic column 5, one end of the telescopic column 5, which is far away from the sliding inclined block 4, is welded with a moving plate 6, a top end of the moving plate 6 is slidably connected with a moving column 7, a connecting portion between the moving column 7 and the moving plate 6 is provided with a sliding hole groove 8, the sliding inclined block 4 forms a telescopic structure with the clamping frame 1 through the first threaded rod 3, the telescopic length of the sliding inclined block 4 is equal to the length of the moving, the width of the sliding inclined block 4 is equal to the height of the sliding hole groove 8, the movement of the moving plate 6 is controlled by driving the sliding inclined block 4 to move, the clamping ring 9 is welded at the top end of the moving column 7 above the sliding hole groove 8, the moving plate 6 forms a telescopic structure through the sliding inclined block 4 and the clamping frame 1, the telescopic length of the moving plate 6 is equal to the width of the sliding inclined block 4, two groups of sliding hole grooves 8 are arranged, the position relationship of the two groups of sliding hole grooves 8 is symmetrical about the moving plate 6, the inclination angle of the sliding hole grooves 8 is 45 degrees, the moving plate 6 drives the moving column 7 to move through the sliding hole groove 8, the clamping operation of the clamping ring 9 is realized, the inner wall of the clamping ring 9 is tightly attached with the conveying pipeline 10, one end of the conveying pipeline 10 is tightly attached with the valve body 11, two groups of clamping rings 9 are arranged, the position distribution of the clamping rings 9 is symmetrical about the moving plate 6, the clamping ring 9 is tightly attached to the conveying pipeline 10, the diameter of the conveying pipeline 10 is equal to that of the valve body 11, the clamping operation on the conveying pipeline 10 is achieved by the clamping ring 9, and the phenomenon that the conveying pipeline 10 is loosened due to work is reduced.

The valve body 11 comprises a backrest 1101, a first sealing ring 1102, a limiting column 1103, a fixing lug ring 1104, a butt clamp bolt 1105, a valve core 1106, a second sealing ring 1107, a rotating cylinder 1108, a third sealing ring 1109, a reinforcing rod 1110 and a rotating shaft 1111, wherein the backrest 1101 tightly attached to the conveying pipeline 10 is attached to the inner wall of the valve body 11, the first sealing ring 1102 is arranged at the connecting part of the backrest 1101 and the conveying pipeline 10, the limiting column 1103 penetrating through the backrest 1101 is arranged at the connecting part of the first sealing ring 1102 and the backrest 1101, the fixing lug ring 1104 is welded to the outer wall of the valve body 11, the butt clamp bolt 1105 fixedly connected with the conveying pipeline 10 penetrates through the fixing lug ring 1104, the valve core 1106 is tightly attached to the inner wall of the backrest 1101, the second sealing ring 1107 is arranged at the connecting part of the valve core 1106 and the backrest 1101, the rotating cylinder 1108 is welded to the inner wall of the valve core 1106, and the third sealing rings 1109 are arranged at the two ends of the rotating, the limiting column 1103 is provided with six groups, the six groups of limiting columns 1103 are distributed in an equiangular circumference manner by taking the central axis of the valve body 11 as the center, the first sealing ring 1102 is tightly attached to the backrest 1101, the valve core 1106 is tightly attached to the backrest 1101 through the second sealing ring 1107, the diameter of the second sealing ring 1107 is 0.9 times of that of the valve core 1106, the rotating cylinder 1108 is tightly attached to the valve body 11 through the third sealing ring 1109, the limiting column 1103 is arranged to facilitate the stable clamping operation of the conveying pipeline 10, the connecting part of the rotating cylinder 1108 and the valve core 1106 is welded with the reinforcing rods 1110, the reinforcing rods 1110 are arranged in two groups 1110, the two groups of reinforcing rods 1110 are symmetrical with respect to the rotating cylinder 1108, the valve core 1106 is eccentric, the eccentric height of the valve core 1106 is equal to the thickness of the reinforcing rods 1110, grooves are formed in the rotating cylinder 1108, the grooves of the rotating cylinder 1108 are matched with the protruding blocks of the rotating shaft 1111, and by arranging the eccentric, realized the accessible operation of transporting the pipeline, the inner wall of a rotation section of thick bamboo 1108 runs through the axis of rotation 1111 that has with work box 12 fixed connection, through carrying out sealed operation to valve body 11, has prolonged the life of valve body 11.

The top end of the valve body 11 is provided with a working box 12, the working box 12 comprises a second hand wheel 1201, a second threaded rod 1202, a sliding block 1203, a rotating rod 1204 and a rotating disc 1205, the second hand wheel 1201 is arranged outside the working box 12, one end of the second hand wheel 1201 extends to the inside of the working box 12 and is welded with the second threaded rod 1202, the outer wall of the second threaded rod 1202 is connected with the sliding block 1203 in a threaded manner, the bottom end of the sliding block 1203 is rotatably connected with the rotating rod 1204, one end of the rotating rod 1204 far away from the sliding block 1203 is fixedly connected with the rotating disc 1205 of the rotating shaft 1111, the central axis of the rotating disc 1205 is coincident with the central axis of the rotating shaft 1111, the rotating disc 1205 forms a rotating structure with the working box 12 through the rotating rod 1204, the rotating angle of the rotating disc 1205 is 90 degrees, the second threaded rod 1202 is provided with two groups, the two groups of second threaded rods 1202 are, and the thread length of the second threaded rod 1202 is 0.7 times of the length of the rotating rod 1204, the rotating disk 1205 is driven to rotate 90 degrees through the two groups of rotating rods 1204, labor-saving operation of rotation of the rotating shaft 1111 is achieved, and control operation of the valve body 11 is achieved through the arrangement of the working box 12.

The working principle of the invention is as follows: when the oblique type butt-clamping butterfly valve is used, firstly, a valve body 11 is assembled, a reinforcing rod 1110 and a valve core 1106 are welded, then, a second sealing ring 1107 is tightly attached to a backrest 1101, the valve core 1106 is tightly connected with the backrest 1101, then, a third sealing ring 1109 is tightly attached to the valve body 11, a rotating cylinder 1108 and the valve body 11 are tightly connected, then, the valve core 1106 and the valve body 11 are installed, then, butt-clamping operation is carried out on the valve body 11, a conveying pipeline 10 and the valve body 11 are tightly attached to each other through the first sealing ring 1102, in a clamping frame 1, a first hand wheel 2 is rotated to drive a first threaded rod 3 to rotate, the first threaded rod 3 drives a sliding oblique block 4 to slide along the inner wall of the clamping frame 1, the inclined angle of an inclined plane of the sliding oblique block 4 is 30 degrees, the inclined plane of the sliding oblique block 4 drives a telescopic column 5 to slide along the inner wall of the clamping frame 1, the motion of flexible post 5 drives the motion of motion board 6, the motion of motion board 6 drives two sets of sliding hole groove 8 movements, sliding hole groove 8 drives the motion of removal post 7, it drives the motion of clamp ring 9 to remove post 7, clamp ring 9 drives pipeline 10 motion, stabilize the operation of pressing from both sides to valve body 11 through pressing from both sides bolt 1105, reduce the problem that leads to the leakage because of pipeline 10 vibration, the operation of opening and shutting is carried out to valve body 11 after that, in work box 12, it drives two sets of second threaded rod 1202 rotations to rotate second hand wheel 1201, the screw direction of two sets of second threaded rod 1202 is opposite, two sets of second threaded rod 1202 rotate and drive two sets of sliding block 1203 relative motion, sliding block 1203 drives dwang 1204 motion, dwang 1204 drives the carousel and rotates 90, carousel 1205 drives case 1106 through axis of rotation 1111 and rotates 90, the operation of opening and shutting of.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. The utility model provides an oblique type butt clamp butterfly valve, includes clamping frame (1), its characterized in that: a first hand wheel (2) is arranged outside the clamping frame (1), one end of the first hand wheel (2) extends to the inside of the clamping frame (1) and is fixedly connected with a first threaded rod (3), one end, far away from the first hand wheel (2), of the first threaded rod (3) is tightly attached to a sliding inclined block (4) in sliding connection with the inner wall of the clamping frame (1), the inclined surface of the sliding inclined block (4) is tightly attached to a telescopic column (5), one end, far away from the sliding inclined block (4), of the telescopic column (5) is welded with a moving plate (6), the top end of the moving plate (6) is connected with a moving column (7) in a sliding mode, a sliding hole groove (8) is formed in the connecting part of the moving column (7) and the moving plate (6), a clamping ring (9) is welded at the top end, located above the sliding hole groove (8), of the moving column (7), and a conveying pipeline (10) is tightly attached to the inner wall of, and one end of the conveying pipeline (10) is tightly attached with a valve body (11), and the top end of the valve body (11) is provided with a working box (12).

2. The oblique butt-clamping butterfly valve according to claim 1, wherein: the sliding inclined block (4) forms a telescopic structure between the first threaded rod (3) and the clamping frame (1), the telescopic length of the sliding inclined block (4) is equal to that of the moving plate (6), the inclined plane inclination angle of the sliding inclined block (4) is 30 degrees, and the width of the sliding inclined block (4) is equal to the height of the sliding hole groove (8).

3. The oblique butt-clamping butterfly valve according to claim 1, wherein: the movable plate (6) forms a telescopic structure through the sliding inclined block (4) and the clamping frame (1), the telescopic length of the movable plate (6) is equal to the width of the sliding inclined block (4), two groups of sliding hole grooves (8) are arranged, the position relation of the two groups of sliding hole grooves (8) is symmetrical relative to the movable plate (6), and the inclination angle of the sliding hole grooves (8) is 45 degrees.

4. The oblique butt-clamping butterfly valve according to claim 1, wherein: the clamping rings (9) are arranged in two groups, the positions of the clamping rings (9) are distributed symmetrically relative to the moving plate (6), the clamping rings (9) are closely attached to the conveying pipeline (10), and the diameter of the conveying pipeline (10) is equal to that of the valve body (11).

5. The oblique butt-clamping butterfly valve according to claim 1, wherein: the valve body (11) comprises a backrest (1101), a first sealing ring (1102), a limiting column (1103), a fixed lug ring (1104), a butt clamp bolt (1105), a valve core (1106), a second sealing ring (1107), a rotating cylinder (1108), a third sealing ring (1109), a reinforcing rod (1110) and a rotating shaft (1111), wherein the backrest (1101) tightly attached to the conveying pipeline (10) is attached to the inner wall of the valve body (11), the first sealing ring (1102) is arranged at the connecting part of the backrest (1101) and the conveying pipeline (10), the limiting column (1103) penetrating through the backrest (1101) is arranged at the connecting part of the first sealing ring (1102) and the backrest (1101), the fixed lug ring (1104) is welded to the outer wall of the valve body (11), the butt clamp bolt (1105) fixedly connected with the conveying pipeline (10) penetrates through the inside of the fixed lug ring (1104), and the valve core (1106) is tightly attached to the inner wall of the backrest (1101), and the junction of case (1106) and back (1101) is provided with second sealing washer (1107), the inside welding of case (1106) has a section of thick bamboo (1108) of rotating, and the inner wall that the both ends of rotating a section of thick bamboo (1108) are located valve body (11) is provided with third sealing washer (1109), the junction welding of rotating a section of thick bamboo (1108) and case (1106) has stiffener (1110), the inner wall of rotating a section of thick bamboo (1108) runs through has axis of rotation (1111) that have with work box (12) fixed connection.

6. The oblique type butt-clamping butterfly valve according to claim 5, wherein: spacing post (1103) are provided with six groups, and six groups of spacing post (1103) use the axis of valve body (11) to be the angular circumference distribution such as the center, first sealing washer (1102) closely laminates with back (1101), case (1106) closely laminates with back (1101) through second sealing washer (1107), and the diameter of second sealing washer (1107) is case (1106) diameter 0.9 times, it closely laminates with valve body (11) through third sealing washer (1109) to rotate a section of thick bamboo (1108).

7. The oblique type butt-clamping butterfly valve according to claim 5, wherein: the reinforcing rods (1110) are arranged in two groups, the two groups of reinforcing rods (1110) are symmetrical relative to the rotating cylinder (1108), the valve core (1106) is eccentric, the eccentric height of the valve core (1106) is equal to the thickness of the reinforcing rods (1110), a groove is formed in the rotating cylinder (1108), and the groove of the rotating cylinder (1108) is matched with the convex block of the rotating shaft (1111).

8. The oblique butt-clamping butterfly valve according to claim 1, wherein: work box (12) include second hand wheel (1201), second threaded rod (1202), sliding block (1203), dwang (1204) and rolling disc (1205), the outside of work box (12) is provided with second hand wheel (1201), and the one end of second hand wheel (1201) extends to the inside welding of work box (12) has second threaded rod (1202), the outer wall threaded connection of second threaded rod (1202) has sliding block (1203), and the bottom of sliding block (1203) has dwang (1204) soon, the one end of sliding block (1203) and axis of rotation (1111) fixed connection's rolling disc (1205) are kept away from in dwang (1204).

9. The oblique type butt-clamping butterfly valve according to claim 8, wherein: the axis of rolling disc (1205) coincides with the axis of rotation (1111), rolling disc (1205) constitutes revolution mechanic through between dwang (1204) and work box (12), and the turned angle of rolling disc (1205) is 90, second threaded rod (1202) are provided with two sets ofly, and the position relation of two sets of second threaded rod (1202) is symmetrical for regarding rolling disc (1205), the screw thread opposite direction of two sets of second threaded rod (1202), and the screw thread length of second threaded rod (1202) is 0.7 times dwang (1204) length.