阅读说明：本技术 管片车车身及管片车 (Segment car body and segment car ) 是由 孛琪山 李剑佩 闫立宏 张飞飞 张任远 靳永强 俞长英 武姣姣 班靖 于 2020-06-17 设计创作，主要内容包括：本发明提供了一种管片车车身及管片车,涉及运载特殊货物的设备技术领域,以解决现有管片车无法与卸载器配合来完成管片的卸载的技术问题。该管片车车身包括沿管片车车身的长度方向依次连接的第一支撑部、连接部和第二支撑部；连接部的宽度小于第一支撑部的宽度和/或第二支撑部的宽度,以使管片车车身在靠近连接部的一侧形成容纳区域。该管片车包括走行机构以及上述的管片车车身,走行机构设置在管片车车身的下方。本发明实现了管片车与卸载器的配合,使卸载器能够在容纳区域中将管片卸载下来。(The invention provides a duct piece vehicle body and a duct piece vehicle, relates to the technical field of equipment for carrying special goods, and aims to solve the technical problem that the existing duct piece vehicle cannot be matched with an unloader to unload duct pieces. The duct piece vehicle body comprises a first supporting part, a connecting part and a second supporting part which are sequentially connected along the length direction of the duct piece vehicle body; the width of the connecting portion is smaller than the width of the first supporting portion and/or the width of the second supporting portion, so that the duct piece vehicle body forms an accommodating area on one side close to the connecting portion. The segment car comprises a walking mechanism and the segment car body, wherein the walking mechanism is arranged below the segment car body. The invention realizes the matching of the segment car and the unloader, so that the unloader can unload the segments in the accommodating area.)

1. The segment car body is characterized by comprising a first supporting part, a connecting part and a second supporting part which are sequentially connected along the length direction of the segment car body;

the width of connecting portion is less than the width of first supporting part and/or the width of second supporting part, so that section of jurisdiction car automobile body is being close to one side formation accommodation area of connecting portion.

2. The segment car body of claim 1, wherein said segment car body includes a first end and a second end in a width direction;

the side edge of the connecting part close to the first end and the first supporting part and the second supporting part jointly form the accommodating area, and/or the side edge of the connecting part close to the second end and the first supporting part and the second supporting part jointly form the accommodating area.

3. The segment car body of claim 1 or 2, wherein the top surface of the connecting portion is lower than the top surfaces of the first and second support portions, a first connecting section is provided between the connecting portion and the first support portion, and a second connecting section is provided between the connecting portion and the second support portion;

the surface height of the first connecting section is gradually reduced from being close to the first supporting part to being close to the connecting part, and/or the surface height of the second connecting section is gradually reduced from being close to the second supporting part to being close to the connecting part.

4. A segment car body according to claim 3, wherein a surface of said first segment forms a first bearing surface and a surface of said second segment forms a second bearing surface;

the first supporting surface and the second supporting surface are both planes;

or, the first supporting surface and the second supporting surface are cambered surfaces, and the radian of the cambered surfaces of the first supporting surface and the second supporting surface is adapted to the radian of the duct piece to be supported.

5. The segment car body of claim 4, further comprising a shock absorbing device disposed on any one or more of the first bearing surface, the second bearing surface, and the top surface of the connection portion.

6. A segment car comprising a running gear and a segment car body according to any one of claims 1 to 5, said running gear being disposed below said segment car body.

7. The segment car of claim 6, wherein the running mechanism comprises at least two running assemblies, the at least two running assemblies being spaced apart along the length of the segment car body;

the walking assembly comprises an axle connected to the segment car body and hubs arranged at two ends of the axle.

8. The segment car of claim 7, further comprising a parking mechanism for locking the running mechanism, wherein the parking mechanism is arranged on one side of the segment car body close to the running mechanism.

9. The segment cart of claim 8 wherein the parking mechanism comprises a driving member and a braking member coupled to each other;

the driving piece is connected on the section of jurisdiction car body, the driving piece drives the brake piece is along being close to or keeping away from wheel hub's direction removes, so that the brake piece supports tightly or breaks away from wheel hub.

10. The segment cart of claim 9, wherein a linkage assembly is disposed between the driving member and the braking member, and the driving member and the braking member are connected by the linkage assembly;

the linkage assembly comprises a linkage rod and a driven rod, the first end of the linkage rod is connected with the output end of the driving part, the second end of the linkage rod is rotatably connected with the first end of the driven rod, and the second end of the driven rod is rotatably connected to the segment car body;

the brake piece is connected in the middle section of driven lever, the braking face of brake piece is towards wheel hub.

Technical Field

The invention relates to the technical field of equipment for carrying special goods, in particular to a segment car body and a segment car.

Background

In tunnel shield construction, a shield construction machine performs tunneling at the front end and has a rear equipment for assisting the construction at the rear of the shield construction machine. The duct piece vehicle is one of important devices in the back distribution equipment and is responsible for conveying duct pieces required by tunnel construction to a newly-tunneled tunnel position so as to fix a tunnel wall.

Fig. 1 is a front view of a conventional segment car, fig. 2 is a top view of the conventional segment car, and fig. 1 and 2 show that the conventional segment car comprises a car body and a traveling mechanism, wherein the car body is of a steel structure with equal width, and the traveling mechanism is installed below the car body and can drive the car body to move on a track. The duct piece vehicle is suitable for tunnels with large width, and the duct pieces can be loaded and unloaded by using a crane. In order to save installation space in a tunnel with a smaller width, an unloader is installed in the tunnel, and the unloader is used for unloading the pipe sheets.

However, the existing segment car has a wider car body, and cannot be matched with an unloader to unload the segment.

Disclosure of Invention

In order to solve at least one problem mentioned in the background art, the invention provides a segment car body and a segment car, which can be matched with an unloader to unload segments.

In order to achieve the above object, in a first aspect, the present invention provides a segment car body including a first support portion, a connection portion, and a second support portion connected in this order along a length direction of the segment car body;

the width of connecting portion is less than the width of first supporting part and/or the width of second supporting part, so that section of jurisdiction car automobile body is being close to one side formation accommodation area of connecting portion.

As a further aspect of the first aspect of the present invention, the segment car body includes a first end and a second end in the width direction;

the side edge of the connecting part close to the first end and the first supporting part and the second supporting part jointly form the accommodating area, and/or the side edge of the connecting part close to the second end and the first supporting part and the second supporting part jointly form the accommodating area.

As a further aspect of the first aspect of the present invention, a top surface of the connecting portion is lower than a top surface of the first supporting portion and a top surface of the second supporting portion, a first connecting section is provided between the connecting portion and the first supporting portion, and a second connecting section is provided between the connecting portion and the second supporting portion;

the surface height of the first connecting section is gradually reduced from being close to the first supporting part to being close to the connecting part, and/or the surface height of the second connecting section is gradually reduced from being close to the second supporting part to being close to the connecting part.

As a further aspect of the first aspect of the present invention, a surface of the first connecting section forms a first supporting surface, and a surface of the second connecting section forms a second supporting surface;

the first supporting surface and the second supporting surface are both planes;

or, the first supporting surface and the second supporting surface are cambered surfaces, and the radian of the cambered surfaces of the first supporting surface and the second supporting surface is adapted to the radian of the duct piece to be supported.

As a further aspect of the first aspect of the present invention, the segment car body further includes a damper device provided on any one or more of the first support surface, the second support surface, and the top surface of the connecting portion.

In a second aspect, the invention provides a segment car, which comprises a running mechanism and the segment car body of the first aspect, wherein the running mechanism is arranged below the segment car body.

As a further aspect of the second aspect of the present invention, the running mechanism includes at least two running assemblies, and the at least two running assemblies are arranged at intervals along the length direction of the segment car body;

the walking assembly comprises an axle connected to the segment car body and hubs arranged at two ends of the axle.

As a further aspect of the second aspect of the present invention, the parking device further includes a parking mechanism for locking the running mechanism, and the parking mechanism is disposed on a side of the segment car body close to the running mechanism.

As a further aspect of the second aspect of the present invention, the parking mechanism includes a driving member and a braking member connected to each other;

the driving piece is connected on the section of jurisdiction car body, the driving piece drives the brake piece is along being close to or keeping away from wheel hub's direction removes, so that the brake piece supports tightly or breaks away from wheel hub.

As a further solution of the second aspect of the present invention, an interlocking component is disposed between the driving element and the braking element, and the driving element and the braking element are connected through the interlocking component;

the linkage assembly comprises a linkage rod and a driven rod, the first end of the linkage rod is connected with the output end of the driving part, the second end of the linkage rod is rotatably connected with the first end of the driven rod, and the second end of the driven rod is rotatably connected to the segment car body;

the brake piece is connected in the middle section of driven lever, the braking face of brake piece is towards wheel hub.

According to the duct piece vehicle body and the duct piece vehicle provided by the invention, the width of the connecting part is set to be smaller than the width of the first supporting part and/or the width of the second supporting part, so that the duct piece vehicle body forms a containing area at one side close to the connecting part, when the duct piece vehicle moves to the position of the unloader, the containing area is aligned with the unloader, the unloader can lift in the containing area, when the unloader rises upwards, duct pieces on the duct piece vehicle can be lifted, and after the duct piece vehicle leaves the position of the unloader, the unloader falls down to finish the unloading of the duct pieces, so that the matching of the duct piece vehicle and the unloader is realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a front view of a prior art segment cart;

FIG. 2 is a top view of a prior art segment cart;

FIG. 3 is a front view of a duct piece cart provided by an embodiment of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 at I;

FIG. 5 is a top view of a duct piece cart provided in accordance with an embodiment of the present invention;

FIG. 6 is a side view of a tube sheet cart provided by an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a tube sheet vehicle and an unloader provided in an embodiment of the present invention;

fig. 8 is a schematic structural diagram of an unloader lift segment according to an embodiment of the present invention.

Description of reference numerals:

10-segment car body; 11-a first support; 12-a second support; 13-a connecting part; 14-a first connection section; 15-a second connection section; 16-a shock-absorbing device; 17-a containment area; 20-a running mechanism; 21-a running assembly; 211-a hub; 212-axle; 30-a parking mechanism; 31-a drive member; 32-a brake element; 33-a linkage assembly; 331-linkage; 332-driven lever; 333-nut; 40-a pipe piece; 50-unloader.

Detailed Description

In the tunnel shield construction, a shield construction machine tunnels at the front end, and a segment car is one of important devices in a rear distribution device and is responsible for conveying segments required by the tunnel construction to the newly tunneled tunnel position so as to fix the tunnel wall. A lot of current small-size tunnels begin to use the uninstaller to uninstall the section of jurisdiction when the construction, but the automobile body broad of current section of jurisdiction car can't cooperate the uninstaller to accomplish the uninstallation of section of jurisdiction. If the automobile body that will have the section of jurisdiction car wholly narrows down, the holding surface of section of jurisdiction can reduce and make the section of jurisdiction obtain good support, simultaneously because the wheel hub that walks the travel mechanism need with the track cooperation, and then the wheel track can not change, wheel hub can lose sheltering from of automobile body and be corroded by the water in the tunnel easily.

The invention provides a segment car body and a segment car, wherein the width of a connecting part is set to be smaller than the width of a first supporting part and/or the width of a second supporting part, so that a containing area is formed on one side of the segment car body close to the connecting part, when the segment car moves to the position of an unloader, the containing area is aligned with the unloader, the unloader can lift in the containing area, when the unloader rises upwards, a segment on the segment car can be lifted, and after the segment car leaves the position of the unloader, the unloader falls down to finish the unloading of the segment, so that the segment car is matched with the unloader.

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in the preferred embodiments of the present invention. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are only some, but not all embodiments of the invention. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention. 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. Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

An embodiment of the invention provides a vehicle body of a duct piece vehicle, fig. 3 is a front view of the duct piece vehicle provided by the embodiment of the invention, fig. 4 is a partially enlarged view of a position i in fig. 3, fig. 5 is a top view of the duct piece vehicle provided by the embodiment of the invention, fig. 6 is a side view of the duct piece vehicle provided by the embodiment of the invention, fig. 7 is a structural schematic diagram of the duct piece vehicle provided by the embodiment of the invention matched with an unloader, fig. 8 is a structural schematic diagram of the unloader lifting duct piece provided by the embodiment of the invention, and fig. 3 to fig. 8 are referred to.

As shown in fig. 3 and 5, the segment car body 10 includes a first support portion 11, a connecting portion 13, and a second support portion 12 connected in this order in a length direction of the segment car body 10, and a width of the connecting portion 13 is smaller than a width of the first support portion 11 and/or a width of the second support portion 12, so that the segment car body 10 forms a receiving area 17 at a side close to the connecting portion 13.

The segment car body 10 shown in fig. 5 is formed with two receiving areas 17, while the connecting portion 13 is smaller in width than both the first support portion 11 and the second support portion 12.

As an achievable embodiment, when two accommodation areas 17 are formed on the segment car body 10, the width of the connecting portion 13 may be smaller than the width of the first support portion 11 or the width of the second support portion 12, that is, the width of one end of the connecting portion 13 is larger and the width of the other end of the connecting portion 13 is smaller, in addition to the case shown in fig. 5. Wherein the width of the narrower end of the connecting portion 13 is smaller than that of the first supporting portion 11, and the width of the wider end of the connecting portion 13 is greater than or equal to that of the second supporting portion 12; alternatively, the width of the narrower end of the connecting portion 13 is smaller than that of the second supporting portion 12, and the width of the wider end of the connecting portion 13 is greater than or equal to that of the first supporting portion 11.

As an achievable embodiment, the receiving region 17 can also be formed on only one side of the segment car body 10, in which case the width of the connecting portion 13 can also be smaller than both the width of the first support portion 11 and the width of the second support portion 12, or the width of the connecting portion 13 can be smaller than only the width of the first support portion 11 or the width of the second support portion 12. The specific structure is the same as that of the two accommodating areas 17 formed on the segment car body 10, and the description is omitted.

When the segment car with the segment car body 10 provided by the embodiment works, the segment car moves along the track in the tunnel, and when the segment car moves to the position of the unloader 50, the accommodating area 17 can be aligned with the unloader 50, as shown in fig. 7; the unloader 50 is then gradually raised to lift the segment 40 up over the containment region 17, causing the segment 40 to disengage from the segment cart, as shown in fig. 8; finally, the segment car is moved away from the position of the unloader 50 and the unloader 50 is dropped to complete the unloading of the segment 40. Therefore, the segment car with the segment car body 10 can be matched with the unloader 50 to unload the segment.

In addition, the width of the first supporting part 11 and the second supporting part 12 of the segment car body 10 is not reduced, so that the segment car body can ensure that the segment 40 is well supported, and the hub 211 of the segment car with the segment car body 10 cannot lose shielding, so that the hub can be prevented from being corroded by water in a tunnel.

When the segment car body 10 has two receiving areas 17, two opposite offloaders 50 may be provided in the tunnel, and the two offloaders 50 may simultaneously lift both sides of the segment 40 to offload the segment 40. When there is only one receiving area 17 on the segment car body 10, an unloader 50 may be provided in the tunnel, the unloader 50 unloading the segment 40 by lifting one side of the segment 40.

With continued reference to fig. 5, the segment car body 10 includes a first end and a second end in the width direction; the side of the connecting portion 13 near the first end and the first and second support portions 11 and 12 together enclose a receiving area 17, and/or the side of the connecting portion 13 near the second end and the first and second support portions 11 and 12 together enclose a receiving area 17.

When the segment car body 10 has two accommodation areas 17, the side of the connecting portion 13 near the first end and the first and second support portions 11 and 12, and the side of the connecting portion 13 near the second end and the first and second support portions 11 and 12 enclose the accommodation areas 17.

When the segment car body 10 has only one accommodation area 17, the side of the connecting portion 13 near the first end forms an accommodation area 17 with the first support portion 11 and the second support portion 12, or the side of the connecting portion 13 near the second end forms an accommodation area 17 with the first support portion 11 and the second support portion 12.

With continued reference to fig. 3, the top surface of the connecting portion 13 is lower than the top surfaces of the first and second support portions 11 and 12, the connecting portion 13 and the first support portion 11 have a first connecting section 14 therebetween, and the connecting portion 13 and the second support portion 12 have a second connecting section 15 therebetween. The surface height of the first connecting section 14 is gradually reduced from being close to the first support part 11 to being close to the connecting part 13, and/or the surface height of the second connecting section 15 is gradually reduced from being close to the second support part 12 to being close to the connecting part 13.

The duct piece 40 is integrally arc-shaped, and when the duct piece 40 is placed on the duct piece car body 10, the duct piece 40 protrudes downwards, so that the outer side of the duct piece 40 can be supported by the first connecting section 14 and the second connecting section 15.

Of course, the top surface of the connecting portion 13 may be equal to or higher than the top surfaces of the first support portion 11 and the second support portion 12, and in this case, support frames may be provided on the first support portion 11 and the second support portion 12 to support the segment 40 placed on the segment car body 10.

The surface of the first connecting section 14 forms a first bearing surface and the surface of the second connecting section 15 forms a second bearing surface. When the segment 40 is supported at the first connection section 14 and the second connection section 15, the outer side surface of the segment 40 is in contact with the first support surface and the second support surface.

The first support surface and the second support surface may have a variety of shapes. For example, the first support surface and the second support surface are both planar. For another example, first holding surface and second holding surface are the cambered surface, and the radian of the cambered surface of first holding surface and second holding surface suits with the radian of the section of jurisdiction 40 of treating the support, the radius of first holding surface and the radius of second holding surface all equal with the radius of the outside cambered surface of section of jurisdiction promptly, when section of jurisdiction 40 is placed on section of jurisdiction car body 10, the lateral surface of section of jurisdiction 40 can be laminated on first holding surface and second holding surface, make and have great holding surface between first holding surface and the section of jurisdiction 40 and between second holding surface and the section of jurisdiction 40, the supporting effect of first holding surface and second holding surface is better.

The segment car body 10 further includes a damper 16, the damper 16 being provided on any one or more of the first support surface, the second support surface, and the top surface of the connecting portion 13. The damping device 16 may be a damping rubber strip, a damping spring, or a damping pad, which is not limited in this embodiment.

The duct piece car can produce the vibration at the in-process of traveling, and duct piece car body 10 that has damping device 16 is when transporting duct piece 40, and duct piece 40 is placed on damping device 16, and damping device 16 can weaken duct piece car body 10 to the vibration of duct piece 40 transmission, prevents that duct piece 40 from taking place to damage at the in-process of transportation.

One arrangement of the damper devices 16 is shown in the segment car body 10 shown in fig. 3 and 5, and in particular, the segment car body 10 is provided with damper devices 16 on both the first support surface and the second support surface, and the damper devices 16 are shock pads.

The embodiment of the invention also provides a segment cart, and please refer to fig. 3 to 8.

The segment car comprises a running mechanism 20 and the segment car body 10, wherein the running mechanism 20 is arranged below the segment car body 10.

When the segment car is used, the running mechanism 20 is placed on the track and can move along the track to drive the segment car body 10 and the segments 40 on the segment car body 10.

The segment car has the segment car body 10 as described above, and as shown in fig. 7 and 8, when the segment car moves to the position of the unloader 50, the accommodation area 17 on the segment car body 10 can be aligned with the unloader 50, as shown in fig. 7; the unloader 50 is then gradually raised to lift the segment 40 up over the containment region 17, causing the segment 40 to disengage from the segment cart, as shown in fig. 8; finally, the segment car is moved away from the position of the unloader 50 and the unloader 50 is dropped to complete the unloading of the segment 40. Therefore, the segment cart can be matched with the unloader 50 to unload the segments.

The running mechanism 20 comprises at least two running assemblies 21, and the at least two running assemblies 21 are arranged at intervals along the length direction of the segment car body 10. The segment car shown in fig. 3 and 5 has two running assemblies 21, and the two running assemblies 21 are arranged at intervals. Of course, the running gear 20 may also comprise three, four, etc. more than two running assemblies 21 arranged at intervals, in addition to the cases shown in fig. 3 and 5.

In addition, as a specific structure of the running assembly can be seen from the side view of the segment car shown in fig. 6, the running assembly 21 includes an axle 212 connected to the segment car body 10 and hubs 211 provided at both ends of the axle 212. When the segment car runs, the two hubs 211 of the running assembly 21 are positioned on two tracks, and the hubs 211 rotate at the ends of the axles 212.

As shown in fig. 3 and 5, the segment car further includes a parking mechanism 30 for locking the running mechanism 20, and the parking mechanism 30 is provided on the segment car body 10 on the side close to the running mechanism 20. When the segment car reaches the position of the unloader 50, a user operates the parking mechanism 30 to enable the parking mechanism 30 to lock the traveling mechanism 20, so that the segment car is prevented from slipping when the unloader 50 unloads the segments 40.

The segment car shown in fig. 5 has two parking mechanisms 30, two traveling mechanisms 20 are respectively adjacent to two hubs 211 of the same traveling unit 21, and the two parking mechanisms 30 can lock the hubs 211 of the same traveling mechanism 20 at the same time to prevent rolling. Certainly, the segment car can also have other quantity of parking mechanisms 30, for example, when the segment car has two walking assemblies 21, the segment car has four parking mechanisms 30, and every parking mechanism 30 is close to a wheel hub 211 respectively, makes four wheel hubs 211 can be locked simultaneously, and four wheel hubs 211 are sliding friction between four wheel hubs 211 and the track when being locked simultaneously, has better swift current car effect.

As shown in fig. 4, the parking mechanism 30 includes an actuating member 31 and a braking member 32 connected to each other. The driving member 31 is connected to the segment car body 10, and the driving member 31 drives the braking member 32 to move in a direction close to or away from the hub 211, so that the braking member 32 abuts against or is separated from the hub 211.

The actuating member 31 refers to a member capable of providing power for the movement of the brake member 32, such as a hydraulic cylinder, an air cylinder, etc. The brake 32 refers to a member capable of generating friction with the hub 211 to restrict rotation of the hub 211, such as a brake shoe shown in fig. 4.

When the segment car walks to the position of the unloader 50, a user can drive the driving piece 31 to drive the brake piece 32 to move towards the direction close to the hub 211 by operating the driving piece 31, the brake piece 32 gradually abuts against the hub 211, the hub 211 cannot rotate, and the segment car is prevented from sliding.

After the unloader 50 finishes unloading the segment 40, a user can operate the driving member 31 to make the driving member 31 drive the braking member 32 to move in a direction away from the hub 211, and the braking member 32 gradually separates from the hub 211 to make the hub 211 rotate.

With continued reference to fig. 4, the parking mechanism 30 further includes an interlocking assembly 33, the interlocking assembly 33 is disposed between the driving member 31 and the braking member 32, and the driving member 31 and the braking member 32 are connected by the interlocking assembly 33. The linkage assembly 33 specifically comprises a linkage rod 331 and a driven rod 332, a first end of the linkage rod 331 is connected to an output end of the driving member 31, a second end of the linkage rod 331 is rotatably connected to a first end of the driven rod 332, a second end of the driven rod 332 is rotatably connected to the segment car body 10, the brake member 32 is connected to a middle section of the driven rod 332, and a braking surface of the brake member 32 faces the hub 211.

The output end of the driving member 31 drives the linkage 331 to move, so that the linkage 331 drives the driven rod 332 to rotate around the second end of the driven rod, and the brake member 32 connected to the middle section of the driven rod 332 is close to or far away from the hub 211, thereby achieving the purpose of abutting against the hub 211 or separating from the hub 211.

In fig. 4, the linkage 331 is specifically a lead screw, the driving member 31 is specifically a hand wheel, and a nut 333 is fixedly arranged on the segment car body 10, and the lead screw passes through the nut 333. When the user operates the parking mechanism 30, the hand wheel is rotated to rotate the lead screw, the lead screw moves along the axis direction thereof under the action of the nut 333, and then the driven rod 332 is driven to rotate around the second end, so that the brake shoe is abutted against or separated from the hub 211. The brake shoe can be switched in the movement direction close to or far from the hub 211 by changing the rotation direction of the hand wheel.

In the description of the embodiments of the present invention, it should be understood that the terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, a fixed connection, an indirect connection through intervening media, a connection between two elements, or an interaction between two elements, unless expressly stated or limited otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. The terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless specifically stated otherwise.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.