Pressure vessel for containing or transporting pressurized gas

Abstract

The invention relates to the field of pressure vessels, in particular to a pressure vessel used for containing or transporting pressurized gas, comprising: a gas tank mechanism comprising a gas tank body, a gas pipe located at the top of the gas tank body, a control valve located outside the gas pipe, and a handle located at the periphery of the top of the gas tank body; the protection mechanism comprises an air bag part arranged outside the air tank body, an air inflation part is arranged on the outer side of the air bag part, an on-off part is arranged on the outer side of the air inflation part, a driving part is arranged on the outer side of the on-off part, and a hanging bracket is arranged on the outer side of the driving part. According to the gas tank, through cooperation of the air bag part and the inflation part, the external collision acting force borne by the gas tank body is buffered by means of the expanded air bag, so that the protection capacity of the gas tank is improved, and the explosion risk caused by damage or deformation of the gas tank is reduced; the protection air bag can be automatically inflated according to the posture of the air tank.

Description

Technical Field

[0001] The present invention relates to the field of pressure vessels, in particular to a pressure vessel for containing or transporting pressurized gas. Background Art

[0002] A pressure vessel is a closed device that contains gas or liquid and bears a certain pressure. By packaging various gases or liquids in pressure vessels, it is convenient for the daily transportation and use of the two. The existing pressure vessels have poor protection, and their own high pressure or the dangerous goods filled inside also greatly increase the risk of using pressure vessels, which can easily cause safety accidents if the pressure vessels are tipped over or bumped during transportation and use, posing a threat to the personal safety of users. Therefore, a pressure vessel for containing or transporting pressurized gas is proposed. Summary of the invention

[0003] In view of the above-mentioned problem or the problem of poor protection of pressure vessels in the prior art, the present invention is proposed.

[0004] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pressure vessel for containing or transporting a gas under pressure.

[0005] To solve the above technical problems, the present invention provides the following technical solutions: comprising: a gas cylinder mechanism, including a gas cylinder body, a gas pipe located at the top of the gas cylinder body, a control valve located outside the gas pipe, and a handle located at the periphery of the top of the gas cylinder body; and The protection mechanism comprises an airbag component arranged outside the gas tank body, an inflatable component is arranged outside the inflatable component, a switching component is arranged outside the inflatable component, a driving component is arranged outside the switching component, a hanger is arranged outside the driving component, and a swing component is also arranged at the bottom of the driving component; It also includes a central cover arranged at the bottom of the gas tank body, a sensing component is arranged through the interior of the central cover, and a connecting component is also arranged on the inner side of the sensing component.

[0006] As a preferred embodiment of the pressure vessel for containing or transporting pressurized gas of the present invention, the airbag component includes a protective airbag wrapped around the bottom periphery of the gas tank body, the bottom of the protective airbag is connected to an inflation pipe, and a pressure relief valve is also installed on the protective airbag.

[0007] As a preferred solution of the pressure container for containing or transporting pressurized gas of the present invention, the inflatable member comprises a placement frame fixedly arranged at the bottom of the gas tank body, a fixing buckle is arranged on the outer side of the placement frame, and a high-pressure gas cylinder is detachably mounted on the inner side of the placement frame; The gas nozzle end of the high-pressure gas cylinder is connected to the inflation tube, and an anti-drop clamp is arranged at the periphery of the connection between the inflation tube and the gas nozzle end.

[0008] As a preferred solution of the pressure vessel for containing or transporting pressurized gas of the present invention, the on-off piece includes a limit rail arranged at the bottom of the gas tank body, the outer part of the limit rail is movably connected with a sliding seat, the bottom of the sliding seat is fixedly connected with a lever, and driving columns are arranged on both sides of the lower end of the lever.

[0009] As a preferred solution of the pressure vessel for containing or transporting pressurized gas of the present invention, wherein: both sides of the driving member are hinged to the hanger, and the hanger is fixed to the gas tank body; The driving member comprises a rotating disk movably arranged outside the lever, a driving groove is reserved on the inner surface of the rotating disk, and a swing rod is fixedly connected to the bottom of the rotating disk; The driving groove is arranged in a half elliptical arc shape, and the driving groove matches the driving column.

[0010] As a preferred solution of the pressure vessel for containing or transporting pressurized gas of the present invention, the swing member includes a swing seat movably sleeved on the outer periphery of the lower part of the swing rod, and a return spring is installed inside the swing seat.

[0011] As a preferred solution of the pressure vessel for containing or transporting pressurized gas of the present invention, the return spring is arranged between the swing rod and the swing seat, and the swing seat is arranged in a truncated cone shape.

[0012] As a preferred embodiment of the pressure vessel for containing or transporting pressurized gas of the present invention, the induction elements are arranged in a ring array about the central cover; The sensing element comprises a telescopic rod penetrating the central cover, the top of the telescopic rod is fixedly connected with a connecting spring, the other end of the connecting spring is fixed with the gas tank body, and a reaction block is arranged outside the upper end of the telescopic rod; The reaction block and the swing table are matched with each other.

[0013] As a preferred solution of the pressure vessel for containing or transporting pressurized gas of the present invention, the adapter is symmetrically arranged with respect to the swing seat, and the adapter cooperates with the swing seat.

[0014] As a preferred solution of the pressure vessel for containing or transporting pressurized gas of the present invention, the adapter comprises an adapter plate located inside the induction element, a center head is integrally provided on the inner edge of the adapter plate, and an adapter spring is provided between the adapter plate and the center cover; The adapter plate is arranged in a half-circular ring shape, and two adapter plates form a complete circular ring.

[0015] The pressure vessel for containing or transporting pressurized gas of the present invention has the following beneficial effects: through the cooperation of the airbag component and the inflatable component, the external collision force exerted on the gas tank body can be cushioned by the expanded airbag, thereby improving the protection capability of the gas tank itself and reducing the risk of explosion caused by damage or deformation of the gas tank; at the same time, with the coordinated setting of the on-off component, the driving component, the sensing component and the adapter component, the automatic inflation of the protective airbag can be realized according to the posture of the gas tank; when the gas tank is in normal use, the airbag is in a compressed state to reduce the space occupied by the gas tank; when the gas tank falls over, the posture of the gas tank can be automatically judged and the airbag can be inflated to protect the gas tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the overall structure of a pressure vessel used to contain or transport pressurized gas.

[0018] Figure 2 A schematic diagram of the partial structure of a pressure vessel used to contain or transport pressurized gas.

[0019] Figure 3 The present invention is a schematic diagram of a partial structure of a protection mechanism for a pressure vessel used to contain or transport pressurized gas.

[0020] Figure 4 The diagram is a schematic diagram of the explosion structure of the switch and drive parts in a pressure vessel used to contain or transport pressurized gas.

[0021] Figure 5 A schematic diagram of the explosion structure of a sensing component and a transition component in a pressure vessel for containing or transporting pressurized gas.

[0022] In the figure: 100, gas tank mechanism; 101, gas tank body; 102, gas pipe; 103, control valve; 104, handle; 200, protection mechanism; 201, air bag component; 201a, protection air bag; 201b, inflation pipe; 201c, pressure relief valve; 202, inflation component; 202a, placement frame; 202b, fixing buckle; 202c, high-pressure gas cylinder; 203, on-off component; 203a, limit rail; 203b, slide seat; 203c, lever ; 203d, driving column; 204, driving member; 204a, rotating disk; 204b, driving slot; 204c, swing rod; 205, hanger; 206, swing member; 206a, swing seat; 206b, return spring; 207, center cover; 208, sensing member; 208a, telescopic rod; 208b, connecting spring; 208c, reaction block; 209, adapter; 209a, adapter plate; 209b, center head; 209c, adapter spring. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0024] Example 1, reference Figure 1~Figure 2 , which is the first embodiment of the present invention, provides a pressure vessel for containing or transporting pressurized gas, which can achieve the effect of improving the protectiveness of the gas cylinder, and includes a gas cylinder mechanism 100 and a protection mechanism 200.

[0025] Specifically, the gas cylinder mechanism 100 includes a gas cylinder body 101 for containing or transporting pressurized gas. The top of the gas cylinder body 101 is connected to an air pipe 102 for filling and discharging gas, and a control valve 103 for controlling the opening and closing of the air pipe 102 is also installed on the outside of the gas cylinder. At the same time, a handle 104 is fixedly provided on the outer periphery of the top of the gas cylinder body 101 for users to carry it conveniently.

[0026] The protection mechanism 200 includes an airbag component 201 sleeved on the outside of the gas tank body 101 , and an inflatable component 202 is arranged on the outside of the airbag component 201 , and the inflatable component 202 is installed on the bottom of the gas tank body 101 .

[0027] Furthermore, the airbag component 201 includes a protective airbag 201a wrapped around the outer periphery of the bottom of the gas tank body 101. The protective airbag 201a can be expanded by filling inert gas into the interior thereof, so that the protective airbag 201a can protect the gas tank body 101 when it falls over. The bottom of the protective airbag 201a is also connected to an inflation tube 201b, and a pressure relief valve 201c for deflation is also installed on the protective airbag 201a.

[0028] The inflatable part 202 includes a placement frame 202a fixedly arranged at the bottom of the gas tank body 101, and a fixing buckle 202b is provided on the outer side of the placement frame 202a for snap-fitting. A high-pressure gas cylinder 202c filled with inert gas is detachably installed on the inner side of the placement frame 202a. The fixing buckle 202b is placed on the outer side of the high-pressure gas cylinder 202c and engages with the protrusions on both sides of the placement frame 202a, thereby fixing the high-pressure gas cylinder 202c. With the help of the setting of the fixing buckle 202b, it is convenient for users to replace the high-pressure gas cylinder 202c. It should be noted that the deflation method of the high-pressure gas cylinder 202c is similar to the deflation method of a lighter, that is, the protrusion at the nozzle end of the high-pressure gas cylinder 202c is pushed outward to achieve deflation.

[0029] Furthermore, the nozzle end of the high-pressure gas cylinder 202c is connected to the inflation tube 201b, and an anti-detachment clamp is arranged on the periphery of the connection between the inflation tube 201b and the nozzle end, so that when the high-pressure gas cylinder 202c is opened, the high-pressure gas can be quickly filled into the protective airbag 201a through the nozzle end and the inflation tube 201b, so that the protective airbag 201a expands to protect the gas tank body 101.

[0030] When in use, after connecting the nozzle end of the high-pressure gas cylinder 202c with the end of the inflation tube 201b, an anti-drop clamp is installed at the connection between the two to ensure a stable connection between the two. When it is necessary to protect the gas tank body 101, open the high-pressure gas cylinder 202c, replenish the gas into the protective airbag 201a to make it collide, and after the protective airbag 201a is inflated, it can provide protection for the gas tank body 101.

[0031] In summary, by setting the protective airbag 201a, the safety of the gas tank body 101 during use can be improved, the internal vibration and external deformation of the gas tank body 101 after tipping over can be effectively reduced, and the safety of the gas tank during use can be improved. At the same time, the setting of the pressure relief valve 201c can facilitate the release of the gas in the protective airbag 201a, so that the protective airbag 201a can be re-compressed to reduce the space occupied by the gas tank body 101 during transportation.

[0032] Example 2, reference Figure 1~Figure 4 , which is the second embodiment of the present invention. Different from the previous embodiment, this embodiment provides a protection mechanism 200 for a pressure vessel for containing or transporting pressurized gas, which can achieve the effect that the protection airbag 201a can automatically switch the use status according to the posture of the gas tank body 101, and it includes the protection mechanism 200.

[0033] Specifically, the protection mechanism 200 also includes an on-off piece 203 arranged on the outside of the air nozzle end of the inflatable piece 202, and driving pieces 204 are arranged on both sides of the lower end of the on-off piece 203, and hangers 205 are movably connected on both sides of the driving piece 204, and the hanger 205 is fixed to the bottom of the gas tank body 101. At the same time, a retractable and swingable swinging piece 206 is also arranged at the bottom of the driving piece 204, and it also includes a center cover 207 fixedly arranged at the center of the bottom of the gas tank body 101, and 8 groups of sensing pieces 208 are arranged in a circular array inside the center cover 207. The 8 groups of sensing pieces 208 can respond to the tipping of the gas tank body 101 in 8 directions.

[0034] Furthermore, the switch 203 includes a limit rail 203a fixedly arranged at the bottom of the gas tank body 101, the limit rail 203a is movably connected to the outside of the limit rail 203a with a slide seat 203b, the bottom of the slide seat 203b is fixedly connected to a lever 203c, the slide seat 203b can drive the lever 203c to slide on the limit rail 203a, and limit the movement trajectory of the lever 203c, ensuring that the lever 203c can only move horizontally, and driving columns 203d are also fixedly arranged on both sides of the lower end of the lever 203c.

[0035] The driving member 204 includes a rotating disk 204a movably arranged outside the lever 203c. The rotating disk 204a is rotatably suspended on the outer side of the lower end of the lever 203c through a hanger 205, and the rotating disk 204a is arranged in an I-shaped double layer. Driving grooves 204b are left on both inner surfaces of the rotating disk 204a, and a swing rod 204c is also fixedly connected to the bottom of the rotating disk 204a.

[0036] The swing member 206 includes a swing seat 206a movably sleeved on the outer periphery of the lower part of the swing rod 204c, and a return spring 206b is installed inside the swing seat 206a. The return spring 206b is arranged between the swing rod 204c and the swing seat 206a, so that the swing rod 204c and the swing seat 206a can perform relative telescopic movement.

[0037] The sensing element 208 includes a telescopic rod 208a that passes through the periphery of the bottom surface of the center cover 207. The top of the telescopic rod 208a is fixedly connected with a connecting spring 208b. The other end of the connecting spring 208b is fixed to the gas tank body 101. The connecting spring 208b can meet the telescopic needs of the telescopic rod 208a through its own elastic force. At the same time, a reaction block 208c is arranged on the outside of the upper end of the telescopic rod 208a.

[0038] Preferably, the driving groove 204b is arranged in a half elliptical arc shape, and the driving post 203d is initially located at the middle end point of the driving groove 204b and can cooperate with the driving groove 204b, so that when the rotating disk 204a swings around the hanger 205, the driving groove 204b can be driven to rotate synchronously, and the relative position between the driving groove 204b and the driving post 203d changes. Therefore, with the half elliptical arc setting of the driving groove 204b, the distance between the driving post 203d and the center of the rotating disk 204a changes with the rotation of the rotating disk 204a, so as to achieve The driving column 203d drives the lever 203c to move horizontally, and through the setting of the driving groove 204b, when the driving column 203d is located at the middle end point of the driving groove 204b, no matter whether the rotating disk 204a rotates clockwise or counterclockwise, the driving column 203d and the lever 203c can move in a single direction toward the center of the rotating disk 204a. That is, when the driving column 203d is located at the initial position, in any rotation direction of the rotating disk 204a, the lever 203c can move the nozzle end of the high-pressure gas cylinder 202c to open the high-pressure gas cylinder 202c.

[0039] The swing seat 206a is arranged in a truncated cone shape, and the eight telescopic rods 208a are dispersedly arranged at equal angles relative to the periphery of the swing seat 206a, and the vertical projection of the reaction block 208c at the upper end of the telescopic rod 208a is located on the swing seat 206a, that is, the reaction block 208c cooperates with the swing table, and the movement trajectory of the reaction block 208c along the axial direction of the swing table interferes with the swing table, so that when any telescopic rod 208a is extended by the elastic force of the connecting spring 208b, the reaction block 208c on the outer side of the telescopic rod 208a is extended with it and contacts with the swing table. At this time, the swing table is affected by a single reaction block 208c. 8c can swing due to uneven force, which can cause the rotating disk 204a to rotate, thereby opening the high-pressure gas cylinder 202c to inflate the protective airbag 201a. When all the telescopic rods 208a are extended at the same time, the collision force on the outside of the swing seat 206a is balanced. At this time, the swing seat 206a will not swing, resulting in the high-pressure gas cylinder 202c not opening. At the same time, the swing seat 206a can be pushed by multiple reaction blocks 208c with the help of the return spring 206b and the swing rod 204c to produce relative movement, and can be quickly reset with the help of the return spring 206b later.

[0040] When in use, when the gas tank body 101 is tilted in any direction, the side opposite to the direction is tilted up, and the limiting force of the telescopic rod 208a corresponding to the tilted end disappears, and the telescopic rod 208a can be extended under the action of the connecting spring 208b, so that the reaction block 208c on it contacts and collides with the swing seat 206a, and then the swing seat 206a and the swing rod 204c drive the rotating disk 204a to rotate, and the high-pressure gas cylinder 202c is opened by the movement of the lever 203c to inflate the protective airbag 201a, and the high-pressure gas The high-pressure gas in the bottle 202c can be inflated before the gas tank body 101 is completely tipped over, and the protective airbag 201a can protect the gas tank body 101 after it is tipped over to reduce the collision damage between the gas tank body 101 and external objects. When the user carries the gas tank body 101, the bottom telescopic rod 208a moves downward synchronously during the transportation process. At this time, the outer periphery of the swing seat 206a is evenly stressed, and the swing seat 206a will not swing, that is, the protective airbag 201a will not be inflated.

[0041] In summary, through the correspondence between the extension and retraction of the sensor 208 and the posture of the gas tank body 101, the automatic switching of the use status of the protective airbag 201a can be achieved. That is, when the gas tank body 101 falls over, the single telescopic rod 208a moves, and the swing seat 206a is unevenly stressed and tilted, so that the high-pressure gas cylinder 202c can be opened and the protective airbag 201a can be inflated to achieve subsequent protection of the gas tank body 101. When the gas tank body 101 is carried, all the telescopic rods 208a move synchronously, and the swing seat 206a is evenly stressed and only telescopically moves without tilting, so that the airbag maintains its original state and is not affected.

[0042] Example 3, reference Figure 1~Figure 5 , which is the third embodiment of the present invention. Different from the previous embodiment, this embodiment provides an adapter 209 for a pressure vessel for containing or transporting pressurized gas, which solves the problem of angle deviation between the sensing member 208 and the swing seat 206a.

[0043] Specifically, the adapter 209 is symmetrically arranged about the swing seat 206a, and the adapter 209 cooperates with the swing seat 206a. The adapter 209 includes an adapter plate 209a located on the inner side of the sensing member 208. A center head 209b is integrally arranged on the inner edge of the adapter plate 209a. The position of the center head 209b coincides with the swing direction of the swing seat 206a. A adapter spring 209c is arranged between the adapter plate 209a and the center cover 207.

[0044] Furthermore, the adapter plate 209a is arranged in a half-circular ring shape, and the two adapter plates 209a form a complete circle, and the eight telescopic rods 208a are divided into two groups along a vertical line perpendicular to the swing direction of the swing seat 206a. The two groups of telescopic rods 208a correspond to the two adapter plates 209a respectively, that is, when a telescopic rod 208a in any group moves downward, the reaction block 208c thereon can first act on the corresponding adapter plate 209a, and then through the downward movement of the adapter plate 209a, the swing seat 206a is swung with the help of the center head 209b on the adapter plate 209a that coincides with the swing direction of the swing seat 206a, thereby ensuring that when the telescopic rod 208a at any angle moves, it can smoothly drive the swing seat 206a to swing.

[0045] When in use, when the telescopic rod 208a is extended and retracted according to the posture of the gas tank body 101, the telescopic rod 208a at any angle can accurately apply force to the swing direction of the swing seat 206a through the center head 209b on the adapter plate 209a, thereby ensuring the smooth swing of the swing seat 206a under any circumstances and realizing the use of the protective airbag 201a.

[0046] In summary, by setting the adapter 209, it can be ensured that the swing seat 206a is subjected to the same force from the telescopic rod 208a at any angle, thereby achieving stable control of the coordination between the high-pressure gas cylinder 202c and the protective airbag 201a, so as to further improve the protection capability of the gas tank body 101 itself.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A pressure vessel for containing or transporting pressurized gas, characterized in that: include, A gas cylinder mechanism (100) comprises a gas cylinder body (101), a gas pipe (102) located at the top of the gas cylinder body (101), a control valve (103) located outside the gas pipe (102), and a handle (104) located at the periphery of the top of the gas cylinder body (101); and, The protection mechanism (200) comprises an airbag component (201) arranged outside the gas tank body (101), an inflatable component (202) being arranged outside the inflatable component (202), an on-off component (203) being arranged outside the on-off component (203), a driving component (204) being arranged outside the driving component (204), a hanger (205) being arranged outside the driving component (204), and a swinging component (206) being arranged at the bottom of the driving component (204); It also includes a central cover (207) arranged at the bottom of the gas tank body (101), a sensing component (208) is arranged inside the central cover (207), and a connecting component (209) is also arranged inside the sensing component (208).

2. A pressure vessel for containing or transporting pressurized gas according to claim 1, characterized in that: The airbag component (201) comprises a protective airbag (201a) wrapped around the periphery of the bottom of the gas tank body (101); the bottom of the protective airbag (201a) is connected to an inflation tube (201b); and a pressure relief valve (201c) is also installed on the protective airbag (201a).

3. A pressure vessel for containing or transporting pressurized gas according to claim 2, characterized in that: The inflatable member (202) comprises a placement frame (202a) fixedly arranged at the bottom of the gas tank body (101), a fixing buckle (202b) being arranged on the outside of the placement frame (202a), and a high-pressure gas cylinder (202c) being detachably mounted on the inside of the placement frame (202a); The gas nozzle end of the high-pressure gas cylinder (202c) is connected to the gas charging tube (201b), and an anti-drop clamp is arranged at the periphery of the connection between the gas charging tube (201b) and the gas nozzle end.

4. A pressure vessel for containing or transporting pressurized gas according to claim 3, characterized in that: The switch (203) comprises a limit rail (203a) arranged at the bottom of the gas cylinder body (101); the outside of the limit rail (203a) is movably connected to a slide seat (203b); the bottom of the slide seat (203b) is fixedly connected to a lever (203c); and driving columns (203d) are arranged on both sides of the lower end of the lever (203c).

5. A pressure vessel for containing or transporting pressurized gas according to claim 4, characterized in that: Both sides of the driving member (204) are hinged to the hanger (205), and the hanger (205) is fixed to the gas tank body (101); The driving member (204) comprises a rotating disk (204a) movably arranged outside the lever (203c), a driving groove (204b) being provided on the inner surface of the rotating disk (204a), and a swing rod (204c) being fixedly connected to the bottom of the rotating disk (204a); The driving groove (204b) is arranged in the shape of a half elliptical arc, and the driving groove (204b) matches the driving column (203d).

6. A pressure vessel for containing or transporting pressurized gas according to claim 5, characterized in that: The swing member (206) comprises a swing seat (206a) movably sleeved on the periphery of the lower part of the swing rod (204c), and a return spring (206b) is installed inside the swing seat (206a).

7. A pressure vessel for containing or transporting pressurized gas according to claim 6, characterized in that: The return spring (206b) is arranged between the swing rod (204c) and the swing seat (206a), and the swing seat (206a) is arranged in a truncated cone shape.

8. A pressure vessel for containing or transporting pressurized gas according to claim 7, characterized in that: The sensing elements (208) are arranged in a ring array with respect to the central cover (207); The sensing element (208) comprises a telescopic rod (208a) penetrating the central cover (207); a connecting spring (208b) is fixedly connected to the top of the telescopic rod (208a); the other end of the connecting spring (208b) is fixed to the gas tank body (101); and a reaction block (208c) is arranged outside the upper end of the telescopic rod (208a); The reaction block (208c) and the swing table are arranged in a matching manner.

9. A pressure vessel for containing or transporting pressurized gas according to claim 8, characterized in that: The adapter (209) is symmetrically arranged with respect to the swing seat (206a), and the adapter (209) matches the swing seat (206a).

10. A pressure vessel for containing or transporting pressurized gas according to claim 9, characterized in that: The adapter (209) comprises an adapter plate (209a) located inside the induction member (208); a center head (209b) is integrally provided on the inner edge of the adapter plate (209a); and an adapter spring (209c) is provided between the adapter plate (209a) and the center cover (207); The adapter plate (209a) is arranged in the shape of a half circular ring, and the two adapter plates (209a) form a complete circular ring.

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