CN113386843B

CN113386843B - Handcart wheel steering assembly and handcart

Info

Publication number: CN113386843B
Application number: CN202110699223.1A
Authority: CN
Inventors: 郭佛钟; 谭彬
Original assignee: Dongguan Jinwang Children Products Co ltd
Current assignee: Dongguan Jinwang Children Products Co ltd
Priority date: 2021-06-23
Filing date: 2021-06-23
Publication date: 2022-06-17
Anticipated expiration: 2041-06-23
Also published as: CN113386843A

Abstract

The application discloses handcart wheel steering assembly, include the wheel carrier, vertically install along the wheel pivot of wheel carrier bottom and with the wheel pivot rotates the wheel subassembly of connecting, the wheel pivot with be equipped with between the wheel subassembly and be used for blockking the gravel and get into the wheel pivot with sand control structure between the wheel subassembly, sand control structure is including the wall structure that blocks that can block the gravel. The application also discloses a trolley. This application can prevent that the grit from getting into between wheel pivot and the wheel subassembly, improves the use experience that turns to smoothness nature and handcart.

Description

Handcart wheel steering assembly and handcart

Technical Field

The application relates to the technical field of trolleys, in particular to a trolley wheel steering assembly and a trolley.

Background

In order to enable the front wheel to be steered, the front wheel assembly of the prior art is usually connected to the front part of the wheel frame through a longitudinal shaft, but during use, the longitudinal shaft of the front wheel is often abraded due to the pores of the side wall of the sand entering the shaft, so that the experience of the trolley is reduced.

Accordingly, it is desirable to design a cart wheel steering assembly and cart that prevents grit from entering between the wheel spindle and the wheel assembly.

Disclosure of Invention

The utility model provides a handcart wheel turns to subassembly and handcart is provided in the not enough of prior art of overcoming to the aim at of this application, can prevent that the grit from getting into between wheel pivot and the wheel subassembly, improves the use experience that turns to smoothness nature and handcart.

The technical scheme of this application provides a handcart wheel steering subassembly, include the wheel carrier, vertically install along the wheel pivot of wheel carrier bottom and with the wheel pivot rotates the wheel subassembly of connecting, the wheel pivot with be equipped with between the wheel subassembly and be used for blockking the gravel and get into the wheel pivot with sand control structure between the wheel subassembly, sand control structure is including the wall structure that blocks that can block the gravel.

Preferably, the blocking wall structure includes a shaft sleeve mounted on the wheel assembly, the bottom of the shaft sleeve is sealed, and when the wheel assembly is assembled, the wheel rotating shaft is inserted into the bottom of the shaft sleeve so that the shaft sleeve at least covers the part of the wheel rotating shaft exposed outside the wheel carrier.

Preferably, the axle sleeve includes an installation groove, the bottom of the installation groove is closed, and a portion of the wheel rotating shaft exposed outside the wheel frame is inserted into the installation groove.

Preferably, the sand control structure further comprises a wheel upper seat connected with the wheel frame, and the wheel upper seat is provided with a cover body covering the upper edge of the shaft sleeve.

Preferably, the top end surface of the wheel assembly is flush with the top end surface of the shaft sleeve, the shaft sleeve is nested in the wheel assembly, and the cover body comprises a transverse baffle plate and a longitudinal baffle plate, wherein the transverse baffle plate transversely covers the shaft sleeve and the top of the wheel assembly, and the longitudinal baffle plate is connected with the transverse baffle plate and longitudinally covers the upper edge of the wheel assembly.

Preferably, the wheel assembly comprises a wheel carrier connecting part and a wheel connecting part, and the wheel carrier connecting part and the wheel connecting part are in transition connection through an inclined plane;

after the installation, the top end face of the wheel carrier connecting part is flush with the top end face of the shaft sleeve, and the wheel carrier connecting part is coated by the cover body.

Preferably, the sand control structure further comprises a pipe plug nested at the bottom of the wheel frame, the wheel rotating shaft is inserted into the pipe plug, and the shaft sleeve of the wheel rotating shaft covers the part of the pipe plug exposed out of the wheel frame.

Preferably, the wheel subassembly is equipped with the mounting hole, the axle sleeve is installed in the mounting hole, the outer wall of axle sleeve sets up round sand control flange along circumference, the sand control flange cover the axle sleeve with the gap between the mounting hole.

Preferably, the vehicle wheel assembly further comprises a locking mechanism, the locking mechanism comprises a locking ring, an elastic part and a slideway, the slideway is arranged on the shaft sleeve, the locking ring is arranged in the slideway in a sliding manner, the end part of the locking ring penetrates out of the wheel assembly, the elastic part is arranged between the wheel assembly and the locking ring, the wheel rotating shaft penetrates through the locking ring, and a clamping groove is formed in the wheel rotating shaft;

when the wheel assembly is locked, the elastic piece pushes the locking ring to slide and be clamped into the clamping groove, and the wheel assembly and the wheel rotating shaft are fixed in the axial direction;

when the wheel assembly is unlocked, the locking ring slides towards the elastic piece and compresses the elastic piece, and the locking ring is separated from the clamping groove so that the wheel assembly and the wheel rotating shaft move in the axial direction.

The invention also discloses a trolley, which comprises the trolley wheel steering assembly.

After adopting above-mentioned technical scheme, have following beneficial effect:

this application can play the protection to the wheel pivot through the sand control structure of setting between wheel pivot and wheel subassembly to can block wheel subassembly gravel on ground and the contact of wheel pivot when using through blockking the wall structure, avoid wheel subassembly gravel to enter into and lead to wearing and tearing between wheel pivot and the wheel subassembly when the pivoted, can improve the smoothness nature that turns to and improve the use experience of handcart and feel.

Drawings

The disclosure of the present application will become more readily understood with reference to the drawings. It should be understood that: these drawings are for illustrative purposes only and are not intended to limit the scope of the present application. In the figure:

FIG. 1 is a general schematic view of a cart wheel steering assembly in one embodiment of the present invention;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is a left side view of FIG. 1;

FIG. 4 is a sectional view taken along line A-A of FIG. 3;

FIG. 5 is a schematic view of a sand control structure according to one embodiment of the present invention;

FIG. 6 is a schematic illustration of a sand control structure with the wheel upper seat removed in one embodiment of the present invention;

FIG. 7 is another angular schematic of FIG. 6;

FIG. 8 is a schematic view of an upper wheel seat according to one embodiment of the present invention;

FIG. 9 is a schematic view of a plug for a pipe in one embodiment of the present invention;

FIG. 10 is a schematic view of the locking mechanism of the present invention in one embodiment, when locked;

FIG. 11 is a schematic view of a wheel assembly of the present invention in one embodiment;

FIG. 12 is a schematic view of the internal structure of the wheel assembly of one embodiment of the present invention;

FIG. 13 is a schematic view of a cart wheel steering assembly of another embodiment of the present invention;

fig. 14 is a schematic view of a cart according to an embodiment of the present invention.

Reference symbol comparison table:

the wheel carrier 1: the connecting pipe body 10 and the second limiting hole 101;

the wheel rotating shaft 2: a clamping groove 20 and a first limiting hole 21;

the wheel assembly 3: mounting holes 30, wheel frame connecting parts 31, wheel connecting parts 32, inclined planes 33, longitudinal ribs 34, mounting columns 35, front forks 36, wheels 37 and communication ports 38;

and (4) a sand control structure:

shaft sleeve 41: the mounting groove 410, the sand control flange 411, the groove 4111 and the second screw hole 4112;

wheel upper seat 42: the cover body 421, the transverse baffle 4211, the longitudinal baffle 4212, the fourth limiting hole 422, the fixture block 423, the connecting sleeve 424 and the locking hole 4241;

pipe plug 43: a communication hole 431 and a third stopper hole 432;

the locking mechanism 5: a locking ring 51, an elastic piece 52 and a slideway 53;

rear wheel 6:

and (7) a bracket:

a seating unit 8.

Detailed Description

Embodiments of the present application are further described below with reference to the accompanying drawings.

It is easily understood that according to the technical solutions of the present application, those skilled in the art can substitute various structures and implementations without changing the spirit of the present application. Therefore, the following detailed description and the accompanying drawings are merely illustrative of the technical solutions of the present application, and should not be construed as limiting or restricting the technical solutions of the present application in their entirety.

The terms of orientation of up, down, left, right, front, back, top, bottom, and the like referred to or may be referred to in this specification are defined relative to the configuration shown in the drawings, and are relative terms, and thus may be changed correspondingly according to the position and the use state of the device. Therefore, these and other directional terms should not be construed as limiting terms. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Throughout the description of the present application, it is to be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "coupled" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, and the two components can be communicated with each other. The foregoing is to be understood as belonging to the specific meanings in the present application as appropriate to the person of ordinary skill in the art.

The first embodiment is as follows:

in some embodiments of the present invention, a wheel steering assembly for a hand truck is disclosed, as shown in fig. 1 and 2, which comprises a wheel frame 1, a wheel spindle 2 longitudinally installed at the bottom of the wheel frame 1, and a wheel assembly 3 rotatably connected to the wheel spindle 2, wherein a sand control structure 4 for preventing sand from entering between the wheel spindle 2 and the wheel assembly 3 is disposed between the wheel spindle 2 and the wheel assembly 3, and the sand control structure 4 comprises a barrier wall structure for preventing sand from entering between the wheel spindle 2 and the wheel assembly 3.

Wherein, wheel subassembly 3 can realize turning to around wheel pivot 2 is rotatory, and can play the protection to wheel pivot 2 through set up between wheel subassembly 3 and wheel pivot 2 and keep off the sand structure, and can block wheel subassembly 3 grit on ground when using and wheel pivot 2 contact through keeping off the wall structure, avoid wheel subassembly 3 grit to enter into and lead to wearing and tearing between wheel pivot 2 and the wheel subassembly 3 when the pivoted, thereby can improve the smoothness nature that turns to and improve the use experience of handcart and feel.

In some embodiments of the present invention, as shown in fig. 2 and 4, the blocking wall structure includes a bushing 41 installed on the wheel assembly 3, and a bottom of the bushing 41 is sealed, and when assembled, the wheel spindle 2 is inserted into the bottom of the bushing 41, so that the bushing 41 covers at least a portion of the wheel spindle 2 exposed outside the wheel carrier 1.

Further, as shown in fig. 4, the upper portion of the wheel rotating shaft 2 is inserted into the bottom of the wheel carrier 1 and connected to the bottom of the wheel carrier 1, the lower portion of the wheel rotating shaft 2 extends from the bottom of the wheel carrier 1 and is exposed outside the wheel carrier 1, the portion of the wheel rotating shaft 2 exposed outside the wheel carrier 1 is inserted into the shaft sleeve 41 and is covered by the shaft sleeve 41, when the wheel assembly 3 rotates, the shaft sleeve 41 moves synchronously with the wheel assembly 3, and the shaft sleeve 41 rotates relative to the wheel rotating shaft 2, so that the gravel cannot contact with the wheel rotating shaft 2 exposed outside the wheel carrier 1 due to the protection of the shaft sleeve 41, and the bottom seal of the shaft sleeve 41 can prevent the gravel on the ground from entering between the shaft sleeve 41 and the wheel rotating shaft 2 from below to cause abrasion on the wheel rotating shaft 2 and the shaft sleeve 41, thereby affecting the smoothness of rotation and the use experience.

In some embodiments of the present invention, as shown in fig. 2 and 4, the sand control structure 4 further includes a pipe plug 43, the pipe plug 43 is nested at the bottom of the wheel carrier 1, the wheel rotating shaft 2 is inserted into the pipe plug 43, and the shaft sleeve 41 covers the portion of the pipe plug 43 exposed out of the wheel carrier 1.

Specifically, as shown in fig. 4, the upper portion of the wheel rotating shaft 2 is connected to the wheel carrier 1 through a pipe plug 43, the bottom of the wheel carrier 1 is provided with a connecting pipe body 10, a housing is arranged outside the connecting pipe body 10, one portion of the pipe plug 43 is embedded into the connecting pipe body 10, and the other portion of the pipe plug 43 extends out of the connecting pipe body 10.

As shown in fig. 4, a first limit hole 21 penetrating through the wheel spindle 2 in the radial direction is formed in the upper portion of the wheel spindle 2, a second limit hole 101 communicating with the inside of the connecting pipe 10 is formed in the side wall of the connecting pipe 10, as shown in fig. 9, a communication hole 431 axially formed and a third limit hole 432 penetrating through the pipe plug 43 in the radial direction are formed in the pipe plug 43, the third limit hole 432 is communicated with the communication hole 431, the first limit hole 21, the second limit hole 101 and the third limit hole 432 are coaxial, the wheel spindle 2 is inserted into the communication hole 431, and the wheel spindle 2 and the pipe plug 43 are fixed to the connecting pipe 10 by inserting a pin shaft into the first limit hole 21, the second limit hole 101 and the third limit hole 432, and the wheel spindle 2 and the pipe plug 43 are relatively fixed in the axial direction, so that the wheel spindle 2 is connected to the wheel carrier 1.

In some embodiments of the present invention, as shown in fig. 4, 6 and 7, the shaft sleeve 41 includes a mounting groove 410, a bottom of the mounting groove 410 is closed, and a portion of the wheel rotating shaft 2 exposed outside the wheel frame 1 is inserted into the mounting groove 410.

Further, as shown in fig. 4, the top of the mounting groove 410 is open, the bottom of the mounting groove 410 is closed, the wheel spindle 2 is inserted into the mounting groove 410 from the top of the mounting groove 410, and since the bottom of the mounting groove 410 is closed, gravel on the ground cannot enter the mounting groove 410, thereby protecting the wheel spindle 2.

In some embodiments of the present invention, as shown in fig. 2, the sand control structure 4 further comprises a wheel upper seat 42 connected to the wheel frame 1, as shown in fig. 4, the wheel upper seat 42 has a cover 421 covering the upper edge of the sleeve 41. The cover 421 can protect the upper side of the bushing 41 and prevent gravel from entering between the bushing 41 and the wheel spindle 2 from the upper side of the bushing 41.

Further, as shown in fig. 4, the wheel upper seat 42 is coated on the outer side of the connecting tube 10 and is fixedly connected with the connecting tube 10, specifically, a fourth limiting hole 422 radially penetrating through the wheel upper seat 42 is arranged in the wheel upper seat 42, the fourth limiting hole 422 is coaxial with the first limiting hole 21, the second limiting hole 101 and the third limiting hole 432, and the wheel upper seat 42, the connecting tube 10, the pipe plug 43 and the wheel spindle 2 are fixed by inserting a pin into the first limiting hole 21, the second limiting hole 101, the third limiting hole 432 and the fourth limiting hole 422.

Further, as shown in fig. 8, a latch 423 is provided on an outer side of the wheel upper seat 42, a bayonet (not shown) is provided on an inner side of the housing, an opening of the bayonet is disposed downward, and the latch 423 is latched into the bayonet to prevent the housing from being opened outward.

In some embodiments of the present invention, as shown in fig. 4, the top end surface of wheel assembly 3 is flush with the top end surface of shaft sleeve 41, shaft sleeve 41 is nested in wheel assembly 3, and cover 421 includes a transverse shield 4211 covering shaft sleeve 41 and the top of wheel assembly 3 in the transverse direction, and a longitudinal shield 4212 connected to transverse shield 4211 and disposed to cover the upper edge of wheel assembly 3 in the longitudinal direction.

Wherein, wheel assembly 3 can further cause the gravel to block, avoids the gravel to get into in the axle sleeve 41. The top end surfaces of the shaft sleeve 41 and the wheel assembly 3 can be shielded by the transverse baffle 4211, gravel is prevented from entering the shaft sleeve 41 and the wheel assembly 3 from the upper side, and gravel can be prevented from entering the shaft sleeve 41 and the wheel assembly 3 from the outer side by the longitudinal baffle 4212.

Wherein the longitudinal shield 4212 is separated from the outer wall of the wheel assembly 3 for ease of assembly and rotation of the wheel assembly 3.

Alternatively, the longitudinal baffle 4212 can also be attached to the outer wall of the wheel assembly 3, the wheel upper seat 42 and the wheel assembly 3 are made of materials with better wear resistance, and the contact surface between the wheel upper seat 42 and the longitudinal baffle 4212 is polished to reduce the friction force between the two, so that the wheel assembly 3 can keep smooth when rotating.

In some embodiments of the present invention, as shown in fig. 4 and 12, the wheel assembly 3 is provided with the mounting hole 30, the shaft sleeve 41 is mounted in the mounting hole 30, and the outer wall of the shaft sleeve 41 is provided with a ring of sand control flange 411 in the circumferential direction, the sand control flange 411 covering the gap between the shaft sleeve 41 and the mounting hole 30. Sand is blocked from entering between the bushing 41 and the mounting hole 30 by the sand control flange 411.

Further, as shown in fig. 12, a plurality of longitudinal ribs 34 are provided on the inner wall of the mounting hole 30 in the longitudinal direction, and as shown in fig. 6 and 7, grooves 4111 matching the longitudinal ribs 34 are provided in the circumferential direction of the sand control flange 411, and the longitudinal ribs 34 are snapped into the grooves 4111, so that the sleeve 41 is limited to rotate in the axial direction, and the installation of the sleeve 41 can be guided by the longitudinal ribs 34.

Further, as shown in fig. 12, a mounting post 35 is further provided on an inner wall of the mounting hole 30, and a first screw hole (not shown) is provided in the mounting post 35 in a longitudinal direction, as shown in fig. 6 and 7, a second screw hole 4112 is provided on the sand control flange 411, and the first screw hole and the second screw hole 4112 are coaxial, and the first screw hole and the second screw hole 4112 are connected by a screw so that the position of the sleeve 41 in the axial direction is fixed.

In some embodiments of the present invention, as shown in fig. 11 and 12, the wheel assembly 3 includes a wheel carrier connection portion 31 and a wheel connection portion 32, and the wheel carrier connection portion 31 and the wheel connection portion 32 are transitionally connected by a slope 33.

After installation, the top end surface of the wheel carrier connection portion 31 is flush with the top end surface of the boss 41, and the wheel carrier connection portion 31 is covered by the cover 421.

Further, as shown in fig. 4, the diameter of the wheel frame connecting portion 31 is smaller than the diameter of the longitudinal baffle 4212 in the cover 421, the diameter of the wheel connecting portion 32 is equal to the diameter of the longitudinal baffle 4212 in the cover 421, and the length of the longitudinal baffle 4212 is equal to the length of the wheel connecting portion 32, and since the wheel frame connecting portion 31 and the wheel connecting portion 32 are transitionally connected through the inclined surface 33, the upper end surface of the wheel connecting portion 32 is lower than the bottom surface of the longitudinal baffle 4212, the bottom of the longitudinal baffle 4212 does not contact with the wheel connecting portion 32, and not only can the function of blocking lateral gravel, but also the function of preventing the longitudinal baffle 4212 from influencing the rotation of the wheel assembly 3 can be achieved. In addition, the slope 33 can guide the lateral gravel, and the gravel can be further prevented from entering the bushing 41.

In some embodiments of the present invention, as shown in fig. 11, wheel assembly 3 further includes a wheel 37 and a front fork 36, wheel 37 is rotatably connected to front fork 36, wheel connecting portion 32 is fixed to the top of front fork 36, and wheel carrier connecting portion 31 is fixed above wheel connecting portion 32.

In some embodiments of the present invention, as shown in fig. 2, the present invention further includes a locking mechanism 5, as shown in fig. 6 and 10, the locking mechanism 5 includes a locking ring 51, an elastic member 52, and a slideway 53, the slideway 53 is provided on the bushing 41, the locking ring 51 is slidably disposed in the slideway 53, an end of the locking ring 51 penetrates through the wheel assembly 3, the elastic member 52 is installed between the wheel assembly 3 and the locking ring 51, the wheel spindle 2 penetrates through the locking ring 51, and the wheel spindle 2 is provided with a locking groove 20;

when the wheel assembly 3 and the wheel spindle 2 are axially fixed, the elastic piece 52 pushes the locking ring 51 to slide and be clamped into the clamping groove 20;

when unlocking, the lock ring 51 slides toward the elastic member 52 and compresses the elastic member 52, and the lock ring 51 is separated from the catch groove 20 so that the wheel assembly 3 is movable in the axial direction with respect to the wheel spindle 2.

Wherein, the elastic element 52 is a spring, a mounting opening for accommodating the spring is arranged on the side wall of the shaft sleeve 41, the spring is arranged in the mounting opening, one end of the spring is connected with the inner wall of the wheel assembly 3, and the other end of the spring is connected with the locking ring 51, as shown in fig. 6 and 12, a communication opening 38 is further arranged on the side wall of the wheel assembly 3, and at least a part of the locking ring 51, which is far away from one end of the spring, penetrates through the communication opening 38 to the outside of the wheel assembly 3.

During locking, the locking ring 51 slides to be clamped into the clamping groove 20 under the elastic force of the spring, so that the wheel assembly 3 and the wheel spindle 2 can be fixed in the axial direction, and meanwhile, the wheel spindle 2 penetrates through the locking ring 51, so that the locking ring 51 does not influence the rotation of the wheel assembly 3. When wheel assembly 3 is dismantled to needs, press the locking ring 51 of arranging in wheel assembly 3 outside for locking ring 51 compression spring, at this moment, locking ring 51 and draw-in groove 20 separation, it can be at the axial activity to make wheel assembly 3 and wheel pivot 2, and then can separate wheel assembly 3 and wheel pivot 2, convenient dismantlement. The wheel assembly 3 can be conveniently mounted and dismounted through the design, so that the wheel assembly 3 can be conveniently replaced and maintained through transportation and subsequent use when products are sold.

In some embodiments of the present invention, when the wheel assembly 3 rotates, the wheel spindle 2 and the shaft sleeve 41 rub against each other, and the tube plug 43 and the shaft sleeve 41 rub against each other, so that the wheel spindle 2, the shaft sleeve 41 and the tube plug 43 are made of polyoxymethylene plastic, which has good wear resistance and ensures the service life of the product.

This device passes through axle sleeve 41 cladding wheel pivot 2 for outside grit can not enter into between axle sleeve 41 and the wheel pivot 2 from the bottom, it is further, expose in wheel pivot 2 and pass through the cover body 421 in the outside part of wheel carrier 1, wheel subassembly 3, the multiple cladding of axle sleeve 41 and stopcock 43, can avoid the grit to enter into between wheel pivot 2 and the axle sleeve 41 from the top of axle sleeve 41 better, cause wearing and tearing to wheel pivot 2 and axle sleeve 41, and then influence pivoted smoothness nature and use experience.

In addition, the device realizes the connection of the wheel assembly 3 and the wheel carrier 1 through the locking mechanism 5, and can facilitate the installation and the disassembly of the wheel assembly 3, so as to facilitate the transportation of products during sale and the replacement and the maintenance of the wheel assembly 3 in subsequent use.

Example two:

the present embodiment discloses a cart, as shown in fig. 14, including the cart wheel steering assembly in the first embodiment, wherein two sets of wheel assemblies 3 are respectively connected through a connecting rod (not shown) as shown in fig. 13, the connecting rod is covered by a shell, specifically, as shown in fig. 8, a connecting sleeve 424 is provided on the inner side of the wheel upper seat 42, both ends of the connecting rod are respectively inserted into the connecting sleeve 424, and locking holes 4241 are provided on both the connecting sleeve 424 and the connecting rod, and the connecting rod and the wheel assemblies 3 are fixed by inserting bolts into the locking holes 4241.

As shown in fig. 13, the two sets of wheel assemblies 3 form a front steering wheel of the cart, the cart further comprises a rear wheel 6, and the front steering wheel and the rear wheel 6 are connected through a foldable bracket 7. A seating unit 8 is detachably mounted on the support frame 7, wherein the seating unit 8 may be a sleeping basket or a seat.

What has been described above is merely the principles and preferred embodiments of the present application. It should be noted that, for a person skilled in the art, several other modifications can be made on the basis of the principle of the present application, and these should also be considered as the scope of protection of the present application.

Claims

1. A handcart wheel steering assembly comprises a wheel frame (1), a wheel rotating shaft (2) longitudinally installed at the bottom of the wheel frame (1) and a wheel assembly (3) rotatably connected with the wheel rotating shaft (2), and is characterized in that a sand control structure (4) used for preventing gravel from entering between the wheel rotating shaft (2) and the wheel assembly (3) is arranged between the wheel rotating shaft (2) and the wheel assembly (3), wherein the sand control structure (4) comprises a blocking wall structure capable of preventing the gravel;

the sand control structure (4) comprises a pipe plug (43), the pipe plug (43) is nested at the bottom of the wheel carrier (1), and the wheel rotating shaft (2) is inserted into the pipe plug (43).

2. A wheel steering assembly for a hand truck as claimed in claim 1, wherein said blocking wall structure comprises a sleeve (41) mounted on said wheel assembly (3), the bottom of said sleeve (41) being sealed, said wheel spindle (2) being inserted into the bottom of said sleeve (41) when assembled, such that said sleeve (41) covers at least the portion of said wheel spindle (2) exposed outside said wheel carrier (1).

3. A cart wheel steering assembly according to claim 2, wherein said bushing (41) comprises a mounting groove (410), the bottom of said mounting groove (410) is closed, and the portion of said wheel axle (2) exposed outside said wheel frame (1) is inserted into said mounting groove (410).

4. A trolley wheel steering assembly according to claim 2, characterized in that the sand control structure (4) further comprises a wheel upper seat (42) connected to the wheel carrier (1), the wheel upper seat (42) having a cover (421) covering the upper edge of the bushing (41).

5. A cart wheel steering assembly according to claim 4, wherein the top end surface of said wheel assembly (3) is flush with the top end surface of said sleeve (41), said sleeve (41) being nested within said wheel assembly (3), said cover (421) comprising a transverse barrier (4211) laterally covering the top of said sleeve (41) and said wheel assembly (3) and a longitudinal barrier (4212) connected to said transverse barrier (4211) and longitudinally disposed to cover the upper edge of said wheel assembly (3).

6. A cart wheel steering assembly according to claim 4, wherein said wheel assembly (3) comprises a wheel carrier connection (31) and a wheel connection (32), said wheel carrier connection (31) and said wheel connection (32) being transitionally connected by a ramp (33);

after the installation, the top end face of the wheel carrier connecting part (31) is flush with the top end face of the shaft sleeve (41), and the wheel carrier connecting part (31) is covered by the cover body (421).

7. A hand truck wheel steering assembly according to claim 2, in which the bush (41) covers the portion of the spigot (43) exposed to the wheel carrier (1).

8. A cart wheel steering assembly according to claim 2, wherein said wheel assembly (3) is provided with a mounting hole (30), said bushing (41) is mounted in said mounting hole (30), an outer wall of said bushing (41) is provided with a circumferential ring of sand control flange (411), said sand control flange (411) covers a gap between said bushing (41) and said mounting hole (30).

9. A cart wheel steering assembly according to claim 2, further comprising a locking mechanism (5), said locking mechanism (5) including a locking ring (51), a resilient member (52) and a slide (53), said slide (53) being provided on said hub (41), said locking ring (51) being slidably disposed within said slide (53), an end of said locking ring (51) extending out of said wheel assembly (3), said resilient member (52) being mounted between said wheel assembly (3) and said locking ring (51), said wheel spindle (2) extending through said locking ring (51), said wheel spindle (2) having a detent (20) thereon;

when the wheel assembly is locked, the elastic piece (52) pushes the locking ring (51) to slide and be clamped into the clamping groove (20), and the wheel assembly (3) and the wheel rotating shaft (2) are fixed in the axial direction;

when unlocking, the locking ring (51) slides towards the elastic piece (52) and compresses the elastic piece (52), and the locking ring (51) is separated from the clamping groove (20) so that the wheel assembly (3) and the wheel rotating shaft (2) are axially movable.

10. A trolley including a trolley wheel steering assembly as claimed in any one of claims 1 to 9.