Adjustable rear wheel expansion device

Abstract

The invention relates to the technical field of mobile vehicles, and discloses an adjustable rear wheel expansion device which comprises a device body. A front case; a rear housing; the connecting assembly is arranged between the front shell and the rear shell, one end of the connecting assembly is slidably connected with the front shell in the front-back direction, and the other end of the connecting assembly is fixedly connected with the rear shell; the first rear wheel assembly and the second rear wheel assembly are arranged on the two opposite sides of the rear shell respectively; the expansion assembly can apply a first acting force to the first rear wheel assembly and the second rear wheel assembly, the first acting force enables the first rear wheel assembly and the second rear wheel assembly to move oppositely, and the expansion assembly can apply a second acting force to the first rear wheel assembly and the second rear wheel assembly; the second acting force enables the first rear wheel assembly and the second rear wheel assembly to move relatively. Adjustment of the distance between the rear wheels is achieved, and the performance of the device in the aspects of the stability and the bearing capacity of the rear wheels is improved.

Description

Technical Field

[0001] The invention relates to the technical field of mobile vehicles, and in particular to an adjustable rear wheel expansion device. Background Art

[0002] In the current market, electric scooters and riding boxes generally adopt a fixed wheelbase design. However, this design often exposes several problems when driving at high speeds, turning, carrying heavy loads or encountering complex road conditions: First, due to the narrow wheelbase, the vehicle is not stable enough when driving at high speeds or making sharp turns, and is prone to rollover or loss of balance; second, the fixed wheelbase design has limitations in weight distribution, resulting in limited carrying capacity; third, the design has low adaptability and cannot meet the needs of users with different riding needs (such as high speed, low speed, loading or daily commuting) to adjust the wheel spacing to optimize the riding experience; finally, the foldable design on the market often sacrifices stability while improving portability, and scooters with wide wheelbases are inconvenient to carry due to their increased size.

[0003] Therefore, how to solve the problem of limited rear wheel stability and load-bearing capacity due to the fixed spacing has become a technical problem that technicians in this field urgently need to solve. Summary of the invention

[0004] In view of this, the present invention proposes an adjustable rear wheel expansion device, aiming to solve the problem of limited rear wheel stability and load-bearing capacity due to fixed spacing in the current technology.

[0005] The present invention provides an adjustable rear wheel expansion device, comprising: device body; A front shell, located at the front side of the device body; A rear housing, located at the rear side of the device body; A connecting component is arranged between the front shell and the rear shell, one end of the connecting component is slidably connected to the front shell in the front-back direction, and the other end of the connecting component is fixedly connected to the rear shell; A first rear wheel assembly and a second rear wheel assembly, wherein the first rear wheel assembly and the second rear wheel assembly are respectively disposed on opposite sides of the rear shell; An extension component, wherein the extension component can apply a first force to the first rear wheel component and the second rear wheel component, wherein the first force causes the first rear wheel component and the second rear wheel component to move away from each other, and the extension component can apply a second force to the first rear wheel component and the second rear wheel component, wherein the second force causes the first rear wheel component and the second rear wheel component to move relative to each other.

[0006] Furthermore, the front shell includes: A first shell and a second shell, wherein the first shell and the second shell are detachably connected; A plurality of first cavities are provided on the side of the first shell facing the second shell, and a plurality of second cavities matching with the first cavities are provided on the side of the second shell facing the first shell. The first cavity and the second cavity cooperate to form a first accommodating cavity, and the first shell and the second shell form a second accommodating cavity, and the second accommodating cavity is arranged to avoid the first accommodating cavity.

[0007] Furthermore, the connection component comprises: A connecting rod is arranged between the front shell and the rear shell, one end of the connecting rod is slidably connected to the front shell in the front-back direction, and the other end of the connecting rod is fixedly connected to the rear shell; A connecting sleeve, a plurality of the connecting sleeves are sleeved outside the connecting rod and are slidably connected to the connecting rod, and the connecting sleeves are clamped with the corresponding first accommodating cavity.

[0008] Furthermore, the first rear wheel assembly includes a first rear wheel; and the second rear wheel assembly includes a second rear wheel.

[0009] Furthermore, the extension component includes: a first adjusting plate, one end of which is slidably connected to the rear housing in the axial direction of the first rear wheel, the other end of which is rotatably connected to the first rear wheel, and a first rack is provided on one side of the first adjusting plate; a second adjusting plate, one end of which is slidably connected to the rear housing in the axial direction of the second rear wheel, the other end of which is rotatably connected to the second rear wheel, and a second rack is provided on one side of the second adjusting plate; An adjusting rod is provided with a transmission tooth, and two sides of the transmission tooth are respectively meshed with the first rack and the second rack.

[0010] Furthermore, the extension component includes: A third shell, wherein the third shell is fixed in the second accommodating cavity, and one end of the adjusting rod is passed through the third shell and slidably matched with the third shell in the front-rear direction; The motor is arranged inside the third shell, and the motor is connected to the adjusting rod.

[0011] Further, the adjustable rear wheel expansion device also includes a limiting assembly, the limiting assembly includes a first limiting groove and a second limiting groove respectively arranged on opposite sides of the rear shell, a first limiting rod arranged on the first adjustment plate, and a second limiting rod arranged on the second adjustment plate, the first limiting rod and the first limiting groove are slidably matched in the axial direction of the first rear wheel, and the second limiting rod and the second limiting groove are slidably matched in the axial direction of the second rear wheel; The lengths of the first limiting groove and the second limiting groove are both smaller than the length of the rear housing in the axial direction of the first rear wheel.

[0012] Furthermore, one end of the adjusting rod is provided with an external thread, and the other end of the adjusting rod is rotatably connected to the rear housing; The limiting assembly also includes a third limiting rod and a limiting sleeve, wherein the third limiting rod is arranged on the adjusting rod and is arranged close to the other end of the adjusting rod and extends radially outwardly along the adjusting rod; the limiting sleeve is arranged on the rear shell and is rotatably connected to the rear shell, and the limiting sleeve is arranged on the adjusting rod, and the limiting sleeve is provided with a third limiting groove matching the third limiting rod, and the third limiting groove is opened along the axial spiral of the limiting sleeve.

[0013] Furthermore, the adjustable rear wheel expansion device also includes a first bearing arranged between the limiting sleeve and the rear shell, and a second bearing arranged between the other end of the adjusting rod and the rear shell.

[0014] Compared with the prior art, the beneficial effect of the present invention is that the front shell of the front shell adjustable rear wheel expansion device provided by the present invention is used to install and fix the front structure of the device body, and at the same time provide connection and support with the front structure. The rear shell is located at the rear side of the device body, and is used to install and fix the rear wheel assembly and expansion assembly and other components to ensure the structural stability and functional integrity of the entire device. The design of the connecting assembly enables the front shell and the rear shell to be flexibly connected in the front and rear directions by sliding. This design not only enhances the flexibility of the device, but also facilitates the adjustment of the relative position between the front and rear shells according to different needs, thereby optimizing the overall performance of the device. The first rear wheel assembly and the second rear wheel assembly are respectively arranged on opposite sides of the rear shell, and they together constitute the rear wheel system of the device, which is responsible for the movement and support of the device. By applying different forces to the first rear wheel assembly and the second rear wheel assembly through the expansion assembly, the flexible adjustment of the rear wheel spacing can be achieved, thereby effectively solving the problem of limited rear wheel stability and carrying capacity in the prior art. This not only improves the adaptability and stability of the device under different road conditions, but also greatly enhances its carrying capacity and service life.

[0015] It can be understood that the adjustable rear wheel extension device provided by the present invention realizes the adjustability of the rear wheel spacing through the extension assembly, so that the first rear wheel assembly and the second rear wheel assembly can move in opposite directions or relative to each other according to actual needs, thereby adjusting the spacing between the two wheels. This not only improves the performance of the device in terms of rear wheel stability and load capacity, but also greatly enhances its ability to adapt to different road conditions and load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 A schematic diagram of the overall structure of an adjustable rear wheel extension device provided by an embodiment of the present invention; Figure 2 A schematic diagram of the structure of the adjustable rear wheel extension device provided by an embodiment of the present invention without the first housing and the connecting sleeve; Figure 3 A schematic diagram of the structure of the adjustable rear wheel expansion device provided by an embodiment of the present invention without the front shell and the rear shell; Figure 4 A schematic structural diagram of a rear wheel assembly and an extension assembly of an adjustable rear wheel extension device provided in an embodiment of the present invention; Figure 5 A schematic structural diagram of an adjustment rod and a transmission gear of an adjustable rear wheel expansion device provided in an embodiment of the present invention; Figure 6 A schematic structural diagram of an adjustment rod of an adjustable rear wheel extension device provided in an embodiment of the present invention.

[0017] In the figure: 100, device body; 110, front shell; 111, first shell; 112, second shell; 114, second cavity; 115, third shell; 120, rear shell; 122, second limiting groove; 131, connecting rod; 132, connecting sleeve; 141, first rear wheel; 142, first adjusting plate; 143, second rear wheel; 144, second adjusting plate; 145, first rack; 146, second rack; 151, adjusting rod; 152, third limiting rod; 153, limiting sleeve; 154, third limiting groove; 155, first bearing; 156, gear; 157, second bearing; 161, first limiting rod; 162, second limiting rod. DETAILED DESCRIPTION

[0018] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0019] See also Figure 1-6 As shown, the present embodiment provides an adjustable rear wheel extension device, comprising: a device body 100; a front shell 110, located at the front side of the device body 100; a rear shell 120, located at the rear side of the device body 100; a connecting component, arranged between the front shell 110 and the rear shell 120, one end of the connecting component is slidably connected to the front shell 110 in the front-to-back direction, and the other end of the connecting component is fixedly connected to the rear shell 120; a first rear wheel assembly and a second rear wheel assembly, the first rear wheel assembly and the second rear wheel assembly are respectively arranged on opposite sides of the rear shell 120; an extension component, the extension component can apply a first force to the first rear wheel assembly and the second rear wheel assembly, the first force causes the first rear wheel assembly and the second rear wheel assembly to move away from each other, and the extension component can apply a second force to the first rear wheel assembly and the second rear wheel assembly, the second force causes the first rear wheel assembly and the second rear wheel assembly to move relative to each other.

[0020] It can be understood that the front shell 110 of the adjustable rear wheel expansion device provided in this embodiment is used to install and fix the front structure of the device body 100, and at the same time provide connection and support with the front structure. The rear shell 120 is located at the rear side of the device body 100, and is used to install and fix components such as the rear wheel assembly and the expansion assembly to ensure the structural stability and functional integrity of the entire device. The design of the connecting assembly enables the front shell 110 and the rear shell 120 to be flexibly connected in the front and rear directions. This design not only enhances the flexibility of the device, but also facilitates the adjustment of the relative position between the front and rear shells 120 according to different needs, thereby optimizing the overall performance of the device. The first rear wheel assembly and the second rear wheel assembly are respectively arranged on opposite sides of the rear shell 120, and they together constitute the rear wheel system of the device, which is responsible for the movement and support of the device. By applying different forces to the first rear wheel assembly and the second rear wheel assembly by the expansion assembly, the flexible adjustment of the rear wheel spacing can be achieved, thereby effectively solving the problem of limited rear wheel stability and carrying capacity in the prior art. This not only improves the adaptability and stability of the device under different road conditions, but also greatly enhances its carrying capacity and service life.

[0021] It can be understood that the adjustable rear wheel extension device provided in this embodiment realizes the adjustability of the rear wheel spacing through the extension assembly, so that the first rear wheel assembly and the second rear wheel assembly can move in opposite directions or relative to each other according to actual needs, thereby adjusting the spacing between the two wheels. This not only improves the performance of the device in terms of rear wheel stability and load capacity, but also greatly enhances its ability to adapt to different road conditions and load conditions.

[0022] It is understandable that the adjustable rear wheel extension device provided in this embodiment can be applied to a suitcase, that is, the front shell 110 is fixedly connected to the bottom of the suitcase. When the user needs to increase the carrying capacity of the suitcase or needs to maintain stability on uneven roads, the distance between the first rear wheel assembly and the second rear wheel assembly can be adjusted by operating the extension assembly.

[0023] It is understandable that the adjustable rear wheel extension device provided in this embodiment can also be applied to an electric scooter, that is, the front shell 110 is fixedly connected to the bottom of the electric scooter. When the user needs to adjust the stability and flexibility of the electric scooter according to different road conditions, the distance between the first rear wheel assembly and the second rear wheel assembly can be adjusted by operating the extension assembly to adapt to different driving needs. This design not only improves the practicality and adaptability of the electric scooter, but also brings a more convenient and comfortable driving experience to the user.

[0024] In this embodiment, for the first rear wheel 141, the first force and the second force are both forces directly applied to the first rear wheel 141 by the operator, or forces applied to the first rear wheel 141 through the second rear wheel 143, the second adjustment plate 144, the transmission gear and the first adjustment plate 142; the directions of the first force and the second force are opposite; similarly, for the second rear wheel 143, the first force and the second force are both forces directly applied to the second rear wheel 143 by the operator, or forces applied to the second rear wheel 143 through the first rear wheel 141, the first adjustment plate 142, the transmission gear and the second adjustment plate 144.

[0025] Specifically, the front shell 110 includes: a first shell 111 and a second shell 112, and the first shell 111 and the second shell 112 are detachably connected; a plurality of first cavities are provided on the side of the first shell 111 facing the second shell 112, and a plurality of second cavities 114 matching the first cavities are provided on the side of the second shell 112 facing the first shell 111, and the first cavity and the second cavity 114 cooperate to form a first accommodating cavity, and the first shell 111 and the second shell 112 form a second accommodating cavity, and the second accommodating cavity is avoided from the first accommodating cavity.

[0026] It can be understood that the detachable connection design of the first shell 111 and the second shell 112 facilitates the maintenance and replacement of the components inside the device, thereby improving the maintainability and service life of the device. At the same time, the avoidance setting of the first accommodating cavity and the second accommodating cavity optimizes the spatial layout inside the device, so that the components can be arranged compactly and orderly, thereby reducing the volume and weight of the device, and facilitating carrying and transportation.

[0027] Specifically, the connecting assembly includes: a connecting rod 131, which is arranged between the front shell 110 and the rear shell 120, one end of the connecting rod 131 is slidably connected to the front shell 110 in the front-to-back direction, and the other end of the connecting rod 131 is fixedly connected to the rear shell 120; a connecting sleeve 132, a plurality of connecting sleeves 132 are sleeved outside the connecting rod 131 and are slidably connected to the connecting rod 131, and the connecting sleeve 132 is clamped with the corresponding first accommodating cavity.

[0028] It can be understood that the sliding connection design of the connecting rod 131 and the connecting sleeve 132, as well as the clamping mode of the connecting sleeve 132 and the first accommodating cavity, ensures the stable sliding of the connecting assembly in the front-to-back direction, while being firmly fixed on the rear shell 120. This not only enhances the stability of the device, but also enables the first rear wheel assembly and the second rear wheel assembly to maintain a stable and smooth movement trajectory when adjusting the spacing, avoiding safety hazards caused by shaking or instability.

[0029] Specifically, the first rear wheel assembly includes a first rear wheel 141 ; the second rear wheel assembly includes a second rear wheel 143 .

[0030] Specifically, the extension component includes: a first adjustment plate 142, one end of the first adjustment plate 142 is slidably connected to the rear shell 120 in the axial direction of the first rear wheel 141, the other end of the first adjustment plate 142 is rotatably connected to the first rear wheel 141, and a first rack 145 is provided on one side of the first adjustment plate 142; a second adjustment plate 144, one end of the second adjustment plate 144 is slidably connected to the rear shell 120 in the axial direction of the second rear wheel 143, the other end of the second adjustment plate 144 is rotatably connected to the second rear wheel 143, and a second rack 146 is provided on one side of the second adjustment plate 144; an adjustment rod 151, the adjustment rod 151 is provided with a transmission tooth, and the two sides of the transmission tooth are respectively meshed with the first rack 145 and the second rack 146.

[0031] It is understandable that the first adjustment plate 142 and the second adjustment plate 144 are respectively connected to the rear shell 120 in a sliding manner in the respective corresponding rear wheel axial directions, and the first rear wheel assembly and the second rear wheel assembly are precisely adjusted through the engagement between the transmission teeth and the first rack 145 and the second rack 146. When the user needs to increase or decrease the distance between the rear wheels, it is only necessary to drive the motor to rotate the adjustment rod 151, and through the engagement between the transmission teeth and the first rack 145 and the second rack 146, the transmission teeth will drive the first rack 145 and the second rack 146 to move in opposite or same directions, thereby driving the first adjustment plate 142 and the second adjustment plate 144 to push or pull the first rear wheel assembly and the second rear wheel assembly to perform corresponding movements. This not only simplifies the operation process, but also improves the accuracy and efficiency of the adjustment. At the same time, the sliding connection between the first adjustment plate 142 and the second adjustment plate 144 and the rear shell 120 ensures the stability and reliability of the expansion assembly when adjusting the distance, and avoids the situation where the use effect is affected by looseness or jamming.

[0032] Specifically, the expansion component includes: a third shell 115, the third shell 115 is fixed in the second accommodating cavity, and one end of the adjustment rod 151 is passed through the third shell 115 and slidably cooperates with the third shell 115 in the front-to-back direction; a motor is arranged inside the third shell 115, and the motor is connected to the adjustment rod 151.

[0033] It can be understood that the setting of the third shell 115 not only provides stable support for the adjustment rod 151, but also limits the movement of the adjustment rod 151 in directions other than the front-to-back direction, further enhancing the stability and reliability of the expansion assembly. At the same time, the fixed connection between the third shell 115 and the second accommodating cavity makes the entire expansion assembly more firmly integrated inside the device, avoiding loosening or damage caused by vibration or impact.

[0034] Specifically, the adjustable rear wheel extension device also includes a limiting assembly, which includes a first limiting groove and a second limiting groove 122 respectively arranged on opposite sides of the rear shell 120, a first limiting rod 161 arranged on the first adjustment plate 142, and a second limiting rod 162 arranged on the second adjustment plate 144. The first limiting rod 161 and the first limiting groove are slidably matched in the axial direction of the first rear wheel 141, and the second limiting rod 162 and the second limiting groove 122 are slidably matched in the axial direction of the second rear wheel 143; the lengths of the first limiting groove and the second limiting groove 122 are both smaller than the axial length of the rear shell 120 in the first rear wheel 141.

[0035] It is understandable that the design of the limit assembly further improves the safety and stability of the device when adjusting the rear wheel spacing. The first limit rod 161 and the second limit rod 162 are respectively slidably matched with the first limit groove and the second limit groove 122, ensuring that the first adjustment plate 142 and the second adjustment plate 144 can move smoothly and accurately in the respective corresponding rear wheel axial directions, avoiding adjustment errors caused by offset or misalignment. At the same time, the length of the first limit groove and the second limit groove 122 is less than the length of the rear shell 120 in the corresponding rear wheel axial direction. Such a design limits the maximum movement range of the first adjustment plate 142 and the second adjustment plate 144, preventing device damage or functional failure caused by excessive adjustment.

[0036] Specifically, one end of the adjusting rod 151 is provided with an external thread, and the other end of the adjusting rod 151 is rotatably connected to the rear shell 120; the limiting assembly also includes a third limiting rod 152 and a limiting sleeve 153, the third limiting rod 152 is arranged on the adjusting rod 151, and is arranged close to the other end of the adjusting rod 151, and extends radially outward along the adjusting rod 151; the limiting sleeve 153 is arranged on the rear shell 120 and is rotatably connected to the rear shell 120, and the limiting sleeve 153 is sleeved on the adjusting rod 151, and the limiting sleeve 153 is provided with a third limiting groove 154 that cooperates with the third limiting rod 152, and the third limiting groove 154 is opened along the axial spiral of the limiting sleeve 153.

[0037] It is understandable that the external thread design at one end of the adjusting rod 151 and the rotational connection mode with the rear shell 120 enable the adjusting rod 151 to rotate smoothly and accurately under the drive of the motor, and then through the engagement of the transmission teeth with the first rack 145 and the second rack 146, the spacing between the first rear wheel assembly and the second rear wheel assembly can be fine-tuned. This not only improves the accuracy of the adjustment, but also ensures the stability and reliability of the adjustment process. At the same time, the matching design of the third limiting rod 152 and the limiting sleeve 153 further enhances the stability and reliability of the adjusting rod 151 during the adjustment process. The third limiting rod 152 extends radially outward from the adjusting rod 151, and cooperates with the third limiting groove 154 spirally opened on the limiting sleeve 153, ensuring that the adjusting rod 151 can move smoothly and accurately during the rotation process, avoiding adjustment errors caused by shaking or offset. This not only improves the accuracy and efficiency of the adjustment, but also brings a smoother and more comfortable operating experience to the user.

[0038] Specifically, the adjustable rear wheel extension device further includes a first bearing 155 disposed between the limiting sleeve 153 and the rear shell 120 , and a second bearing 157 disposed between the other end of the adjusting rod 151 and the rear shell 120 .

[0039] It can be understood that the provision of the first bearing 155 and the second bearing 157 ensures that the rotation connection between the limit sleeve 153 and the rear housing 120, and between the adjustment rod 151 and the rear housing 120, is smoother and more flexible. This not only reduces the friction resistance during the rotation process, improves the durability and service life of the device, but also makes it easier and more labor-saving for the user to adjust the rear wheel spacing.

[0040] It is understandable that the adjustable rear wheel extension device provided in this embodiment realizes flexible and precise adjustment of the distance between the rear wheels, greatly improving the adaptability and stability of the device in different usage scenarios. Whether it is a suitcase or an electric scooter, the distance between the rear wheels can be quickly adjusted according to actual needs by simply operating the extension components, thereby ensuring the stability and carrying capacity of the device under various road conditions. This design not only improves the practicality and flexibility of the product, but also brings a more convenient and efficient use experience to users. At the same time, the precise coordination and firm connection between the components ensure the stability and reliability of the device during long-term use, providing users with a more secure and reliable use experience.

[0041] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0042] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0043] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0044] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An adjustable rear wheel extension device, characterized in that: include: device body; A front shell, located at the front side of the device body; A rear housing, located at the rear side of the device body; A connecting component is arranged between the front shell and the rear shell, one end of the connecting component is slidably connected to the front shell in the front-back direction, and the other end of the connecting component is fixedly connected to the rear shell; A first rear wheel assembly and a second rear wheel assembly, wherein the first rear wheel assembly and the second rear wheel assembly are respectively disposed on opposite sides of the rear shell; An extension component, wherein the extension component can apply a first force to the first rear wheel component and the second rear wheel component, wherein the first force causes the first rear wheel component and the second rear wheel component to move away from each other, and the extension component can apply a second force to the first rear wheel component and the second rear wheel component, wherein the second force causes the first rear wheel component and the second rear wheel component to move relative to each other.

2. The adjustable rear wheel extension device according to claim 1, characterized in that: The front shell comprises: A first shell and a second shell, wherein the first shell and the second shell are detachably connected; A plurality of first cavities are provided on the side of the first shell facing the second shell, and a plurality of second cavities matching with the first cavities are provided on the side of the second shell facing the first shell. The first cavity and the second cavity cooperate to form a first accommodating cavity, and the first shell and the second shell form a second accommodating cavity, and the second accommodating cavity is arranged to avoid the first accommodating cavity.

3. The adjustable rear wheel extension device according to claim 2, characterized in that: The connection component comprises: A connecting rod is arranged between the front shell and the rear shell, one end of the connecting rod is slidably connected to the front shell in the front-back direction, and the other end of the connecting rod is fixedly connected to the rear shell; A connecting sleeve, a plurality of the connecting sleeves are sleeved outside the connecting rod and are slidably connected to the connecting rod, and the connecting sleeves are clamped with the corresponding first accommodating cavity.

4. The adjustable rear wheel extension device according to claim 3, characterized in that: The first rear wheel assembly includes a first rear wheel; the second rear wheel assembly includes a second rear wheel.

5. The adjustable rear wheel extension device according to claim 4, characterized in that: The expansion components include: a first adjusting plate, one end of which is slidably connected to the rear housing in the axial direction of the first rear wheel, the other end of which is rotatably connected to the first rear wheel, and a first rack is provided on one side of the first adjusting plate; a second adjusting plate, one end of which is slidably connected to the rear housing in the axial direction of the second rear wheel, the other end of which is rotatably connected to the second rear wheel, and a second rack is provided on one side of the second adjusting plate; An adjusting rod is provided with a transmission tooth, and two sides of the transmission tooth are respectively meshed with the first rack and the second rack.

6. The adjustable rear wheel extension device according to claim 5, characterized in that: The expansion components include: A third shell, wherein the third shell is fixed in the second accommodating cavity, and one end of the adjusting rod is passed through the third shell and slidably matched with the third shell in the front-rear direction; The motor is arranged inside the third shell, and the motor is connected to the adjusting rod.

7. The adjustable rear wheel extension device according to claim 6, characterized in that: The adjustable rear wheel extension device further includes a limiting assembly, the limiting assembly including a first limiting groove and a second limiting groove respectively arranged on opposite sides of the rear shell, a first limiting rod arranged on the first adjustment plate, and a second limiting rod arranged on the second adjustment plate, the first limiting rod and the first limiting groove are slidably matched in the axial direction of the first rear wheel, and the second limiting rod and the second limiting groove are slidably matched in the axial direction of the second rear wheel; The lengths of the first limiting groove and the second limiting groove are both smaller than the length of the rear housing in the axial direction of the first rear wheel.

8. The adjustable rear wheel extension device according to claim 7, characterized in that: One end of the adjusting rod is provided with an external thread, and the other end of the adjusting rod is rotatably connected to the rear housing; The limiting assembly also includes a third limiting rod and a limiting sleeve, wherein the third limiting rod is arranged on the adjusting rod and is arranged close to the other end of the adjusting rod and extends radially outwardly along the adjusting rod; the limiting sleeve is arranged on the rear shell and is rotatably connected to the rear shell, and the limiting sleeve is arranged on the adjusting rod, and the limiting sleeve is provided with a third limiting groove matching the third limiting rod, and the third limiting groove is opened along the axial spiral of the limiting sleeve.

9. The adjustable rear wheel extension device according to claim 8, characterized in that: The adjustable rear wheel expansion device also includes a first bearing arranged between the limiting sleeve and the rear shell, and a second bearing arranged between the other end of the adjusting rod and the rear shell.

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