CN220053799U - Annular RGV drive assembly - Google Patents

Abstract

The present utility model relates to a circular RGV drive assembly comprising: a rotating seat (11), a wheel set support (12) connected to the lower side of the rotating seat (11), a driving wheel set (13) connected to the wheel set support (12), an auxiliary limit wheel set (14) and a power source (15); the auxiliary limiting wheel sets (14) are arranged below the driving wheel sets (13), and the auxiliary limiting wheel sets (14) are respectively arranged at two axial sides of the driving wheel sets (13); the axial direction of the driving wheel set (13) is perpendicular to the axial direction of the auxiliary limiting wheel set (14); the auxiliary limit wheel set (14) comprises: an eccentric sleeve (141), a first rotating shaft (142) connected with the eccentric sleeve (141), and an auxiliary wheel (143); the auxiliary limiting wheel set (14) is connected with the wheel set support (12) through the eccentric sleeve (141).

Description

Annular RGV drive assembly

Technical Field

The utility model relates to the technical field of logistics, in particular to an annular RGV driving assembly.

Background

With the progress of the age, the automatic logistics technology also has been developed in a rapid and rapid way, and in particular, the logistics automation advances a step towards logistics intellectualization. Accordingly, RGV (Rail Guided Vehicle) has also found wide application and innovation as a member of automated logistics equipment.

In the prior art, an RGV mainly comprises a trolley body, a vehicle body driving device, a conveying device arranged on the vehicle body and the like, wherein a driving component for realizing operation as the RGV is a key part of the driving component, and the quality of the driving component directly influences the operation posture of the RGV and the service life of the RGV. In particular, RGVs use circular rails during shuttle transport, where the arcuate portion is encountered with the risk of the drive assembly becoming disengaged from the rail and causing rollover. For example, chinese patent CN218412944U discloses a high-speed annular RGV device for intrusion prevention detection, in which steering assistance is achieved by only providing a guide wheel on one side of a driving assembly, and this method can achieve a certain rollover prevention effect, but wear of the guide wheel and deformation of a track occur after long-term use, and this situation may cause an increase in a gap between the guide wheel and the track, which may easily cause a decrease in a limit capacity of the guide wheel, and an increase in rollover risk. In addition, the installation position of the guide wheel is fixed and cannot be flexibly adjusted according to actual conditions, so that the side turning risk after long-time operation is further increased.

Disclosure of Invention

It is an object of the present utility model to provide a toroidal RGV drive assembly that improves its operational reliability.

To achieve the above object, the present utility model provides a toroidal RGV drive assembly comprising: the rotating seat is connected with a wheel set support at the lower side of the rotating seat, and is connected with a driving wheel set, an auxiliary limiting wheel set and a power source;

the auxiliary limiting wheel sets are arranged below the driving wheel sets, and the auxiliary limiting wheel sets are respectively arranged at two axial sides of the driving wheel sets;

the axial direction of the driving wheel set is perpendicular to the axial direction of the auxiliary limiting wheel set;

the auxiliary limiting wheel set comprises: the eccentric sleeve is connected with the first rotating shaft and the auxiliary wheel;

the auxiliary limiting wheel set is connected with the wheel set support through the eccentric sleeve.

According to one aspect of the utility model, the wheelset support comprises: a top plate, side plates and bottom end supports;

the top plate is arranged above the bottom end supporting piece and is arranged in parallel with the bottom end supporting piece;

the side plates are used for connecting the top plate and the bottom end supporting piece, and two side plates are oppositely arranged along the width direction of the top plate;

the bottom end supporting piece is fixed on the outer side of the side plate and extends in a direction away from the side plate;

the driving wheel set is connected with the side plates and is positioned between the two side plates;

the auxiliary limiting wheel set is connected with the bottom end supporting piece, and the auxiliary wheel is located below the bottom end supporting piece.

According to one aspect of the present utility model, the bottom end supporting members are plate-shaped structures corresponding to the side plates one by one, or are ring-shaped structures connected with both side plates at the same time.

According to one aspect of the utility model, the drive wheel set comprises: a driving wheel, a driving shaft coaxially connected with the driving wheel and a driving shaft rotation support;

the driving shafts are rotatably supported and arranged on the side plates in one-to-one correspondence with the side plates;

one end of the driving shaft extends out to be in transmission connection with the power source.

According to one aspect of the utility model, the output shaft of the power source is provided with a connecting hole;

the connecting hole is connected with the extending end of the driving shaft.

According to one aspect of the utility model, the swivel mount comprises: a cross roller bearing, a rotary connecting piece coaxially connected with the cross roller bearing, and a fixed connecting piece connected with the rotary connecting piece;

the crossed roller bearings are supported on the upper side of the top plate supported by the wheel sets.

According to one aspect of the utility model, a first swing limiting structure is arranged on the upper side of the top plate adjacent to the crossed roller bearing along the length direction of the top plate;

along the length direction of the fixed connecting piece, the downside of the fixed connecting piece is provided with a second swing limit structure corresponding to the first swing limit structure.

According to one aspect of the utility model, the upper side of the fixed connecting piece is also provided with a sliding component;

along the length direction of fixed connection spare, the slip subassembly interval is provided with two, and two slip subassembly's direction of activity with the width direction of fixed connection spare is unanimous.

According to one aspect of the utility model, the eccentric sleeve comprises: the eccentric sleeve comprises an eccentric sleeve main body and a limiting protruding structure arranged at one end of the eccentric sleeve main body;

the limiting protruding structure protrudes along the radial direction of the eccentric sleeve main body;

the axial length of the eccentric sleeve main body is smaller than the thickness of the bottom end supporting piece;

the first rotation shaft includes: the locking piece is characterized by comprising a rotary connecting part, a positioning protruding part, a nested connecting part, a threaded connecting part and a locking piece, wherein the rotary connecting part is used for connecting the auxiliary wheel, the positioning protruding part is coaxially connected with the rotary connecting part, the nested connecting part is coaxially connected with the positioning protruding part and is used for being connected with the eccentric sleeve, the threaded connecting part is coaxially connected with the nested connecting part, and the locking piece is connected with the threaded connecting part;

the limiting protruding structure and the positioning protruding part are respectively propped against the upper side and the lower side of the bottom end supporting piece.

According to the scheme of the utility model, the auxiliary limiting wheel set with the eccentric sleeve is adopted, so that the position of the auxiliary wheel can be flexibly adjusted conveniently by rotating the eccentric sleeve, the distance between the auxiliary wheel and the side surface of the track can be conveniently and accurately controlled, proper matching with two sides of the track can be realized under the conditions of track installation errors and machining errors of wheel set support, the rollover resistance of the scheme is effectively ensured, and the requirement on track construction precision is reduced.

According to the scheme of the utility model, the rotating shaft position is conveniently and flexibly adjusted by arranging the eccentric sleeve, and the structural complexity of the rotating shaft position adjusting device is effectively simplified. In addition, through the mode that adopts eccentric sleeve and first pivot to separate the setting, can effectively reduce the processing degree of difficulty of each part, effectual saving manufacturing cost. Meanwhile, when any part is worn, only one part needs to be replaced, so that the maintenance cost is effectively reduced.

According to the scheme of the utility model, the bottom end supporting piece is in a rectangular annular shape, and is fixedly connected with the side plates through the inner side of the middle opening, so that the effect of surrounding the side plates is realized, the inclination of the side plates is effectively restrained, the whole wheel group supporting structure is more stable, and particularly, the bearing stability and reliability are greatly ensured through the limiting effect of the bottom end supporting piece when a heavy object is borne. In addition, through setting up the bottom support piece into annular structure, its bulk strength is high, and for this reason, be favorable to guaranteeing the installation and the operation stability of supplementary spacing wheelset.

According to the scheme of the utility model, the rotating seat adopts the crossed roller bearing as a steering mechanism of the driving wheel group, can bear larger tipping moment, is convenient to cut and lubricate and has long service life.

According to the scheme of the utility model, the power source is connected with the driving shaft by adopting the mounting hole on the output shaft, so that the intermediate connection is reduced, and the load intensity is improved.

According to the scheme of the utility model, the swing limiting structure is arranged on the rotating seat, so that the difficulty of the RGV in-orbit is effectively reduced, and meanwhile, the damage caused by pulling of a motor cable in the hoisting process is avoided.

Drawings

FIG. 1 is a block diagram schematically illustrating a circular RGV drive assembly according to an embodiment of the present utility model;

FIG. 2 is a top view schematically illustrating a circular RGV drive assembly according to an embodiment of the present utility model;

FIG. 3 is a block diagram schematically illustrating an auxiliary spacing wheel set in accordance with one embodiment of the present utility model;

fig. 4 is a structural view schematically showing a rotary seat according to an embodiment of the present utility model.

Detailed Description

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required to be used in the embodiments will be briefly described below. It is apparent that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.

In describing embodiments of the present utility model, the terms "longitudinal," "transverse," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer" and the like are used in terms of orientation or positional relationship based on that shown in the drawings, which are merely for convenience of description and to simplify the description, rather than to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and thus the above terms should not be construed as limiting the present utility model.

The present utility model will be described in detail below with reference to the drawings and the specific embodiments, which are not described in detail herein, but the embodiments of the present utility model are not limited to the following embodiments.

As shown in connection with fig. 1, 2, 3 and 4, according to one embodiment of the present utility model, a circular RGV drive assembly of the present utility model includes: the wheel group support 12 is connected to the lower side of the rotating seat 11, and the driving wheel group 13, the auxiliary limiting wheel group 14 and the power source 15 are connected with the wheel group support 12. In this embodiment, the driving wheel set 13 and the power source 15 are provided to realize the running of the whole driving assembly along the guide rail, and the auxiliary limiting wheel set 14 is used for rolling connection with two sides of the guide rail, so as to limit the whole driving assembly and prevent rollover. Further, the auxiliary limit wheel sets 14 are disposed below the driving wheel sets 13, and the auxiliary limit wheel sets 14 are disposed on both sides of the driving wheel sets 13 in the axial direction (for example, the auxiliary limit wheel sets 14 are disposed in two, four, etc.); in addition, the axial direction of the driving wheel set 13 is perpendicular to the axial direction of the auxiliary limiting wheel set 14. Through the above arrangement, the auxiliary limit wheel sets 14 are respectively arranged at the two sides of the guide rail to prevent any side of the whole driving assembly from being inclined greatly.

In the present embodiment, the auxiliary stopper wheelset 14 includes: an eccentric sleeve 141, a first rotating shaft 142 and an auxiliary wheel 143 connected to the eccentric sleeve 141; the auxiliary limiting wheel set 14 is connected with the wheel set support 12 through an eccentric sleeve 141.

Through the arrangement, the position of the first rotating shaft 142 in the installation is adjustable in the auxiliary limiting wheel set 14 by adopting the eccentric sleeve 141, specifically, the angle of the eccentric sleeve 141 is adjusted, so that the eccentric hole of the eccentric sleeve 141 for installing the first rotating shaft 142 is displaced in the horizontal direction, and the position of the first rotating shaft 142 is adjusted. In addition, the mode of adjusting the position of the rotating shaft by arranging the eccentric sleeve 141 is convenient and flexible, and the structural complexity of the rotating shaft position adjusting device is effectively simplified. In addition, the eccentric sleeve 141 and the first rotating shaft 142 are arranged separately, so that the processing difficulty of each part can be effectively reduced, and the production cost is effectively saved. Meanwhile, when any part is worn, only one part needs to be replaced, so that the maintenance cost is effectively reduced.

As shown in connection with fig. 1, 2, 3 and 4, the wheelset support 12 according to one embodiment of the present utility model comprises: top plate 121, side plate 122 and bottom end support 123. In this embodiment, the wheel group support 12 has a rectangular frame structure as a whole; the top plate 121 may be configured as a rectangular plate, and the top plate 121 is located above the bottom end support 123. In the present embodiment, the top plate 121 is disposed parallel to the bottom end support 123. In the present embodiment, the side plate 122 is also made of a rectangular plate body, wherein the side plate 122 is for connecting the top plate 121 and the bottom end support 123, and two side plates 122 are provided opposite to each other in the width direction of the top plate 121. In the present embodiment, the bottom end support 123 is fixed to the outer side of the side plate 122, and extends in a direction away from the side plate 122. The connection to the auxiliary limit wheel set 14 is achieved by means of a bottom end support 123 provided,

in the present embodiment, the side plates 122 mainly play a role of supporting connection, wherein the driving wheel set 13 is connected with the side plates 122 and is located between the two side plates 122; in the present embodiment, in order to secure the mounting reliability of the side plates 122 and the top plate 121, a connection beam may be provided between the two side plates 122 and connected to the inner side of the top plate 121 to reinforce between the side plates 122 and the top plate 121. In addition, in order to avoid interference of the connection beam with other structures, it may be provided at edges of the top plate 121 and the side plate 122.

In the present embodiment, the auxiliary stopper wheel set 14 is connected to the bottom end support 123, and the auxiliary wheel 143 is located below the bottom end support 123. Wherein, through set up the installation through-hole that runs through its body on bottom support 123, then install eccentric sleeve 141 in the installation through-hole can, further through rotating eccentric sleeve 141 realize the adjustment of its central eccentric hole position after installation first pivot 142, then can lock first pivot 142 and eccentric sleeve 141 on bottom support 123 through the retaining member.

As shown in connection with fig. 1, 2, 3 and 4, according to one embodiment of the present utility model, the bottom end support 123 is a ring-shaped structure that is simultaneously connected with the two side plates 122. Wherein, bottom support 123 wholly is the rectangle cyclic annular, and it is through the inboard of middle open-ended and the mutual fixed connection of curb plate 122 to the effect including the curb plate 122 is realized, the effectual slope that restraines curb plate 122, makes the structure of whole wheelset support 12 more stable, especially in the heavy load of bearing, through the restriction effect very big assurance that the bottom support 123 bears reliable and stable. In addition, by setting the bottom end supporting member 123 to be a ring structure, the overall strength thereof is high, and for this reason, it is advantageous to ensure the stable installation and operation of the auxiliary stopper wheelset 14.

In another embodiment, the bottom end supporting pieces 123 are plate-shaped structures corresponding to the side plates 122 one by one, wherein the bottom end supporting pieces 123 may be provided in a rectangular plate shape.

As shown in connection with fig. 1, 2, 3 and 4, according to one embodiment of the present utility model, the driving wheel set 13 comprises: a driving wheel 131, a driving shaft 132 coaxially connected to the driving wheel 131, and a driving shaft rotation support 133. In the present embodiment, the drive shaft rotational bearings 133 are mounted on the side plate 122 in one-to-one correspondence with the side plate 122. In this embodiment, one end of the drive shaft 132 extends out of driving connection with the power source 15.

As shown in fig. 1, according to an embodiment of the present utility model, an output shaft of a power source 15 is provided with a connection hole; wherein the connection hole is connected to the protruding end of the driving shaft 132. In the present embodiment, the power source 15 may be implemented by a gear motor.

As shown in connection with fig. 1, 2, 3 and 4, according to one embodiment of the present utility model, the swivel base 11 includes: a cross roller bearing 111, a rotary link 112 coaxially connected to the cross roller bearing 111, and a fixed link 113 connected to the rotary link 112. In the present embodiment, the cross roller bearing 111 is supported on the upper side of the top plate 121 of the wheel group support 12. The rotating connecting piece 112 is mounted on the crossed roller bearing 111, so that the rotating connecting piece 112 can rotate relative to the top plate 121, and further, the fixed connecting piece 113 is arranged to connect the wheel set support 12 and the RGV vehicle body.

As shown in fig. 1, 2, 3 and 4, according to an embodiment of the present utility model, a first swing limiting structure 1211 is provided adjacent to the crossed roller bearing 111 at an upper side of the top plate 121 in a length direction of the top plate 121; along the length direction of the fixed connection 113, the lower side of the fixed connection 113 is provided with a second swing limit structure corresponding to the first swing limit structure 1211.

Through the above arrangement, the manner of arranging the swing limiting structures (i.e., the first swing limiting structure 1211 and the second swing limiting structure) between the top plate 121 and the fixed connection member 113, respectively, can effectively limit the rotation range of the whole driving assembly, avoid excessive rotation of the driving assembly, and inhibit the risk of rollover.

In the present embodiment, the first swing limiting structure 1211 may be provided as a long bar-shaped block structure, one side thereof adjacent to the crossed roller bearing 111 may be provided as an arc shape to avoid interference with the crossed roller bearing 111, and the other side is a plane flush with the edge of the top plate 121. Accordingly, the second swing limiting structure provided at the lower side of the fixed connection 113 may be provided as a bar-shaped block structure, and the opposite side thereof to the first swing limiting structure 1211 is also provided as a plane. To ensure that the driving assembly has a sufficient rotation angle, it may be achieved by adjusting the separation distance between the first and second swing limit structures 1211 and 1211. In the present embodiment, the second swing limiting structure may also be implemented by a protrusion structure or the like on the fixed connection 113.

As shown in fig. 1, 2, 3 and 4, according to an embodiment of the present utility model, the upper side of the fixed connection 113 is further provided with a sliding assembly 1131. In the present embodiment, two sliding assemblies 1131 are disposed at intervals along the length direction of the fixed connector 113, and the moving direction of the two sliding assemblies 1131 coincides with the width direction of the fixed connector 113. In the present embodiment, to limit the sliding range of the driving assembly, limiting members may be disposed at opposite ends of the sliding assembly 1131, respectively.

In this embodiment, the sliding assembly 1131 includes a slide rail and a slider; wherein the slide rail may be provided on the fixed connection 113 and the slider is connected with the corresponding RGV car body position. In this embodiment, the limiting members for limiting the sliding range may be disposed at opposite ends of the sliding rail.

Through the arrangement, the sliding component 1131 is arranged on the fixed connecting piece 113, so that a certain wheelset adjusting space is generated in the direction perpendicular to the advancing direction by adopting the RGV of the scheme, and the stable trafficability can still be realized under the condition that the width between two tracks changes, the blocking condition and wheelset abrasion caused by the width change between the two tracks are prevented, complex operation scenes are effectively adapted, and the running stability and reliability are ensured.

As shown in fig. 1, according to an embodiment of the present utility model, the eccentric sleeve 141 includes: the eccentric sleeve main body and the limit protruding structure arranged at one end of the eccentric sleeve main body. In this embodiment, the present utility model is not limited to this embodiment. The limit protruding structure protrudes along the radial direction of the eccentric sleeve main body; the limiting protrusion structure may be a continuous ring structure or may be a plurality of protrusions circumferentially spaced along the eccentric sleeve 141.

In the present embodiment, the axial length of the eccentric sleeve body is smaller than the thickness of the bottom end support 123. Through the above-mentioned setting to make things convenient for spacing protrusion structure can be abundant with bottom support 123 offset.

As shown in fig. 1, according to an embodiment of the present utility model, the first shaft 142 includes: a positioning protruding part coaxially connected with the rotation connecting part, a nested connecting part coaxially connected with the positioning protruding part and used for being connected with the eccentric sleeve 141, a threaded connecting part coaxially connected with the nested connecting part, and a locking piece connected with the threaded connecting part. In this embodiment, the length of the nested connection portion is smaller than the length of the eccentric sleeve 141, so that it is convenient to realize that the limiting protruding structure and the positioning protruding portion respectively abut against the upper side and the lower side of the bottom end supporting member 123, so as to facilitate locking and fixing of the locking member, and keep the position of the eccentric sleeve stable.

As shown in fig. 1, according to an embodiment of the present utility model, a rough structure is provided on a side of the limit projection structure against the bottom end support 123, and/or a rough structure is provided on a side of the positioning projection portion against the bottom end support 123. In this embodiment, the roughness structure may be provided as regular or random arrangement of protrusions, wherein the protrusion structure may be one of a cone-shaped protrusion, a hemispherical protrusion, and a stripe-shaped protrusion (whose cross section may be provided as a triangle or a circle).

Through the above arrangement, the installation position of the eccentric sleeve 141 and/or the first rotating shaft 142 can be fixed through the functions of the locking member and the coarse structure, so that the use stability of the utility model is effectively ensured.

The foregoing is merely exemplary of embodiments of the utility model and, as regards devices and arrangements not explicitly described in this disclosure, it should be understood that this can be done by general purpose devices and methods known in the art.

The above description is only one embodiment of the present utility model, and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (9)

1. A circular RGV drive assembly, comprising: a rotating seat (11), a wheel set support (12) connected to the lower side of the rotating seat (11), a driving wheel set (13) connected to the wheel set support (12), an auxiliary limit wheel set (14) and a power source (15);

the auxiliary limiting wheel sets (14) are arranged below the driving wheel sets (13), and the auxiliary limiting wheel sets (14) are respectively arranged at two axial sides of the driving wheel sets (13);

the axial direction of the driving wheel set (13) is perpendicular to the axial direction of the auxiliary limiting wheel set (14);

the auxiliary limit wheel set (14) comprises: an eccentric sleeve (141), a first rotating shaft (142) connected with the eccentric sleeve (141), and an auxiliary wheel (143);

the auxiliary limiting wheel set (14) is connected with the wheel set support (12) through the eccentric sleeve (141).

2. The annular RGV drive assembly of claim 1, wherein the wheelset support (12) comprises: a top plate (121), side plates (122) and a bottom end support (123);

the top plate (121) is positioned above the bottom end supporting piece (123), and the top plate (121) is arranged in parallel with the bottom end supporting piece (123);

the side plates (122) are used for connecting the top plate (121) and the bottom end supporting piece (123), and two side plates (122) are oppositely arranged along the width direction of the top plate (121);

the bottom end supporting piece (123) is fixed on the outer side of the side plate (122) and extends in a direction away from the side plate (122);

the driving wheel set (13) is connected with the side plates (122) and is positioned between the two side plates (122);

the auxiliary limiting wheel set (14) is connected with the bottom end supporting piece (123), and the auxiliary wheel (143) is arranged below the bottom end supporting piece (123).

3. The annular RGV driving assembly according to claim 2, wherein the bottom end support (123) is a plate-like structure in one-to-one correspondence with the side plates (122), or the bottom end support (123) is an annular structure simultaneously connected with both side plates (122).

4. An annular RGV drive assembly according to claim 3, characterized in that the drive wheel set (13) comprises: a driving wheel (131), a driving shaft (132) coaxially connected to the driving wheel (131), and a driving shaft rotation support (133);

the driving shaft rotary supports (133) are arranged on the side plates (122) in one-to-one correspondence with the side plates (122);

one end of the driving shaft (132) extends out to be in transmission connection with the power source (15).

5. The annular RGV drive assembly according to claim 4, characterized in that the output shaft of the power source (15) is provided with a connection hole;

the connecting hole is connected with the extending end of the driving shaft (132).

6. The annular RGV drive assembly according to claim 5, wherein the swivel mount (11) comprises: a cross roller bearing (111), a rotary connecting piece (112) coaxially connected with the cross roller bearing (111), and a fixed connecting piece (113) connected with the rotary connecting piece (112);

the crossed roller bearing (111) is supported on the upper side of a top plate (121) of the wheel group support (12).

7. The annular RGV drive assembly of claim 6, wherein a first swing limit structure (1211) is provided adjacent to the cross roller bearing (111) on an upper side of the top plate (121) along a length direction of the top plate (121);

along the length direction of the fixed connecting piece (113), a second swing limiting structure corresponding to the first swing limiting structure (1211) is arranged on the lower side of the fixed connecting piece (113).

8. The annular RGV drive assembly according to claim 7, wherein the stationary connection (113) is further provided with a sliding assembly (1131) on its upper side;

along the length direction of the fixed connecting piece (113), two sliding assemblies (1131) are arranged at intervals, and the moving directions of the two sliding assemblies (1131) are consistent with the width direction of the fixed connecting piece (113).

9. The annular RGV drive assembly of claim 8, wherein the eccentric sleeve (141) comprises: the eccentric sleeve comprises an eccentric sleeve main body and a limiting protruding structure arranged at one end of the eccentric sleeve main body;

the limiting protruding structure protrudes along the radial direction of the eccentric sleeve main body;

the axial length of the eccentric sleeve body is smaller than the thickness of the bottom end support (123);

the first rotating shaft (142) includes: a positioning protruding part coaxially connected with the rotating connecting part, a nested connecting part coaxially connected with the positioning protruding part and used for being connected with the eccentric sleeve (141), a threaded connecting part coaxially connected with the nested connecting part, and a locking piece connected with the threaded connecting part;

the limiting protruding structure and the positioning protruding part are respectively propped against the upper side and the lower side of the bottom end supporting piece (123).