KR102863938B1 - Driving module having variable stiffness for mid-wheel mobility and mobility having the same - Google Patents

Abstract

A variable stiffness drive module for a middle-wheel drive type mobility, and a mobility including the same, wherein the variable stiffness drive module includes a wheel unit, a fixed pivot unit, a front wheel link unit, a rear wheel link unit, and a coupling unit. The wheel unit includes a middle wheel to which driving force is provided, and a front wheel and a rear wheel respectively positioned in front and behind the middle wheel. The fixed pivot unit includes a plurality of pivots that rotate while being fixed to a fixed body. The front wheel link unit is connected from the front wheel to the fixed body through the fixed pivot unit. The rear wheel link unit is connected from the rear wheel to the fixed body through the fixed pivot unit. The coupling unit is connected to an end of the front wheel link unit and an end of the rear wheel link unit, and is controlled to have a stiffness that varies depending on a driving environment.

Description

Variable stiffness driving module for mid-wheel drive mobility, and mobility including the same {DRIVING MODULE HAVING VARIABLE STIFFNESS FOR MID-WHEEL MOBILITY AND MOBILITY HAVING THE SAME}

The present invention relates to a variable stiffness drive module for a middle-wheel drive type mobility, and mobility including the same, and more particularly, to a variable stiffness drive module for a middle-wheel drive type mobility, which is applied to mobility such as an electric wheelchair to drive the middle wheel and drive the mobility, and which can effectively absorb external shocks while providing excellent road grip through an optimal design of a damper and link structure together with a variable stiffness structure, and mobility including the same.

In various mobility devices, including electric wheelchairs, in which users ride and move, the structure of the suspension is the most important factor that affects the user's riding comfort and driving performance.

The suspension structure of the above mobility device can be designed in a wide variety of configurations based on factors such as the location of the damper and the connection structure to the driving wheels. In particular, a mid-wheel drive suspension structure provides driving force to the mid-wheel to enable the vehicle to drive, and has been applied to numerous mobility devices, such as electric wheelchairs, to date.

For example, U.S. Patent No. 7516984 discloses a technology for a structure in which the front and rear wheels are connected by a link structure based on a pivot structure located in the middle wheel, thereby allowing stable driving by changing the position of the front wheels even on a sloped road surface.

In addition, Japanese Patent No. 6992016 discloses a swing arm link structure for a middle-wheel drive wheelchair, in which the front and rear wheels are designed to be relatively variable in height with respect to the middle wheel, thereby stably driving while maintaining contact with the slope of the road surface.

However, for mid-wheel-drive vehicles, maintaining high traction is crucial, particularly when navigating varying slopes, to ensure effective transmission of the driving force from the mid-wheel to the ground. Furthermore, varying the rigidity of the drive module according to the driving environment is essential to ensure passenger comfort and driving stability. This requires the design of a suspension structure with variable stiffness.

U.S. Patent No. 7516984 Japanese Patent No. 6992016

Accordingly, the technical problem of the present invention is conceived from this point, and the purpose of the present invention is to provide a variable stiffness drive module for a middle-wheel drive type mobility that can be applied to a mobility such as an electric wheelchair to drive the middle wheel, and can effectively absorb external shocks while providing excellent road grip through an optimal design of a damper and link structure together with a variable stiffness structure.

In addition, another object of the present invention is to provide mobility including the driving module.

According to one embodiment of the present invention, a variable stiffness drive module for realizing the above-described object includes a wheel unit, a fixed pivot unit, a front wheel link unit, a rear wheel link unit, and a coupling unit. The wheel unit includes a middle wheel to which driving force is provided, and front and rear wheels respectively positioned in front and behind the middle wheel. The fixed pivot unit includes a plurality of pivots that rotate while being fixed to a fixed body. The front wheel link unit is connected from the front wheel to the fixed body through the fixed pivot unit. The rear wheel link unit is connected from the rear wheel to the fixed body through the fixed pivot unit. The coupling unit is connected to an end of the front wheel link unit and an end of the rear wheel link unit, and is controlled to have a stiffness that varies depending on a driving environment.

In one embodiment, the coupling unit may be controlled so that the ends of the front link unit and the rear link unit can move freely within a predetermined space in a normal driving environment, and may be controlled so that the ends of the front link unit and the rear link unit are coupled to each other in a driving environment where an external force is generated.

In one embodiment, the coupling unit may include a first coupling portion connected to an end of the front wheel link unit, and a second coupling portion connected to an end of the rear wheel link unit.

In one embodiment, the first and second connecting portions are arranged to be spaced apart from each other by a predetermined distance, and each of the first and second connecting portions may include an elastic body.

In one embodiment, the first and second connecting portions are arranged to be spaced apart from each other by a predetermined distance in a normal driving environment, and can be brought into close contact with each other in a driving environment where an external force is generated.

In one embodiment, the first coupling portion may extend in one direction and form a coupling space having a predetermined length therein, and the second coupling portion may include a fastening portion extending in the same direction as the first coupling portion and positioned inside the coupling space.

In one embodiment, the first coupling portion may have a frame shape and form a coupling space having a predetermined area therein, and the second coupling portion may be a fastening portion positioned inside the coupling space.

In one embodiment, the first coupling portion may have a frame shape and form a coupling slot extending in an arc shape therein, and the second coupling portion may be a fastening portion positioned inside the coupling slot.

In one embodiment, the fastening member can be freely movable within the first coupling member in a normal driving environment, and can be fixed on the first coupling member in a driving environment where an external force is applied.

In one embodiment, the coupling unit may include an elastic body or damper connected to both ends of the front link unit and the rear link unit.

In one embodiment, the front wheel link unit may include a first front wheel link connected between the front wheel and the first pivot of the fixed pivot portion, a second front wheel link connected between the first pivot and the coupling unit, and a front wheel damper connected between the first front wheel link and the second pivot of the fixed pivot portion.

In one embodiment, the rear wheel link unit may include a first rear wheel link connected between the rear wheel and a third pivot of the fixed pivot portion, a second rear wheel link connected between the third pivot and the coupling unit, and a rear wheel damper connected between the first rear wheel link and a fourth pivot of the fixed pivot portion.

In one embodiment, the method further includes a middle wheel link unit connected between the middle wheel, the fixed body, and the coupling unit, wherein the middle wheel link unit may further include a first middle wheel link connected between the middle wheel and the first pivot, a second middle wheel link connected between the middle wheel and the coupling unit, and a middle wheel damper connected between the coupling unit and a fifth pivot of the fixed pivot portion.

In one embodiment, the coupling unit may include a first coupling portion connected to an end of the front wheel link unit, a second coupling portion connected to an end of the rear wheel link unit, and a third coupling portion connected to the middle wheel link unit.

In one embodiment, the first coupling portion may have a frame shape and form first and second coupling spaces that are spaced apart from each other and have a predetermined area, the second coupling portion may be a fastening portion positioned inside the first coupling space, and the third coupling portion may be a fastening portion positioned inside the second coupling space.

In one embodiment, the fastening portion can be freely moved in the first coupling space and the second coupling space in a normal driving environment, and can be fixed on the first coupling portion in a driving environment where an external force is generated.

Another embodiment of the mobility for realizing the above-described other object of the present invention includes the driving module, a lower frame on which the driving module is provided, and a boarding section on which a user boards the upper portion of the lower frame.

According to embodiments of the present invention, a coupling unit is included that connects front and rear wheels to each other, or connects front, middle, and rear wheels to each other, and the rigidity of the coupling unit is varied according to the driving environment, thereby providing optimal driving stability and user riding convenience according to various driving environments.

In this case, the coupling unit can provide a space in which each link unit connected to the front and rear wheels, or the front, middle, and rear wheels, can freely move relative to each other in a normal driving environment, thereby providing a user's riding convenience during normal driving with relatively little rigidity. In contrast, in a driving environment where a certain external force is generated, such as when overcoming an obstacle, the coupling unit can provide relatively great rigidity by connecting the link units to each other to limit the mutual movement between the link units, thereby improving the ease of overcoming an obstacle.

The variable stiffness structure of the above-mentioned coupling unit can be implemented through various structures, thereby providing an optimal stiffness variable suspension structure according to various design adaptability and driving environments.

In particular, in the case of a combined unit in which the front, middle, and rear wheels are all connected, by forming multiple movable spaces for the link units, a free movable space for each link unit can be formed, thereby providing excellent riding comfort with relatively small rigidity.

In addition, in the case of a combination unit in which the front, middle, and rear wheels are all connected, the middle wheel link unit is designed to rotate in the opposite direction to the rotational direction of the front wheel link unit and the rear wheel link unit, thereby further improving the grip of the middle wheel in driving environments such as overcoming obstacles.

Furthermore, link units extending between the front, middle, and rear wheels and the connecting unit are designed to be optimally connected with the minimum number of links, thereby simplifying the design while improving the user's riding convenience, grip, and driving stability.

FIG. 1 is a side view illustrating mobility according to one embodiment of the present invention.
Figure 2 is a schematic diagram illustrating the drive module of Figure 1.
Figures 3a to 3e are schematic diagrams showing examples of the coupling unit of Figure 2.
Figure 4 is a schematic diagram illustrating a drive module according to another embodiment of the present invention.
Figure 5 is a schematic diagram illustrating a drive module according to another embodiment of the present invention.
Figure 6 is a schematic diagram illustrating the coupling unit of Figure 5.

The present invention is susceptible to various modifications and takes various forms, and thus embodiments are described in detail herein. However, this is not intended to limit the present invention to a specific disclosed form, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Similar reference numerals have been used to designate similar components throughout the description of each drawing. While terms such as "first," "second," etc. may be used to describe various components, these components should not be limited by these terms.

The above terms are used solely to distinguish one component from another. The terms used in this application are used solely to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, it should be understood that terms such as “comprise” or “consist of” are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

Hereinafter, with reference to the attached drawings, a preferred embodiment of the present invention will be described in more detail.

FIG. 1 is a side view illustrating mobility according to one embodiment of the present invention.

Referring to FIG. 1, the mobility (1) according to the present embodiment includes a lower frame (10), a boarding part (20), and a driving module (50).

The lower frame (10) is a frame formed on the lower side of the mobility (1), and the drive module (50) is positioned inside. In this case, the lower frame (10) may be formed to cover the outside of the drive module (50) as shown, but is not limited thereto, and may be formed in various structures as long as it has a structure that covers all or part of the drive module (50).

The above driving module (50) includes a wheel unit (100) and, as described below, implements a suspension function in relation to the driving of the wheel unit (100).

The above wheel unit (100) includes a front wheel (110) located at the front end of the mobility (1), a rear wheel (130) located at the rear end, and a middle wheel (120) located between the front wheel (110) and the rear wheel (130). The middle wheel (120) is connected to a driving unit that provides driving force, although not shown.

That is, in the present embodiment, the wheel unit (100) drives the mobility (1) by a middle wheel (120) to which driving force is provided, and the middle wheel (120) can be formed to have a relatively large radius compared to the front wheel (110) and the rear wheel (130).

In addition, the structure of the above driving module (50) and the driving operation linked to the wheel unit (100) will be described with reference to the drawings described below.

The above boarding part (20) is provided on the upper part of the lower frame (10) and includes a structure for a user to board.

In this embodiment, the mobility (1) may be an electric wheelchair as illustrated, and if the mobility (1) is an electric wheelchair, the boarding part (20) may be manufactured to conform to the structure of the electric wheelchair.

That is, it may include a saddle part (21) on which the user sits, a backrest part (22) on which the user leans his/her back, an armrest part (23) on which the user rests his/her arms, a headrest part (24) on which the user leans his/her head, and a footrest part (25) on which the user positions his/her feet.

In contrast, the above mobility (1) may be a mobility structure of a different type than an electric wheelchair, and in this case, it may be designed in various ways taking into consideration the riding form or riding posture of the user to be transported.

Furthermore, the boarding part (20) can be selectively attached and detached from the lower frame (10), thereby allowing the same driving module (50) to be applied to mobility of various structures.

Below, the structure and operation of the driving module (50) will be described in more detail.

Figure 2 is a schematic diagram illustrating the drive module of Figure 1.

First, referring to FIG. 2, the drive module (50) includes, in addition to the wheel unit (100) described above, a fixed pivot unit (200), a front wheel link unit (300), a rear wheel link unit (400), and a coupling unit (500).

Meanwhile, although the wheel unit (100) and other components of the drive module (50) are shown as being formed on the same plane through FIG. 2, this is for convenience of explanation, and in reality, the wheel unit (100) may be arranged on the outside of the lower frame (10) compared to other components.

In addition, the lower frame (10) may include a structure to which the wheel unit (100) or other components of the driving module (50) are fixed, including a fixed body (11).

That is, although the wheel unit (100) and other components of the drive module (50) are shown as overlapping each other in the drawing, in reality, they do not overlap and interfere with each other except for the parts where they are connected to each other, and can be spaced apart with a predetermined gap.

However, this gap is a self-evident matter that can be designed in various ways, and in order to easily explain the driving mechanism of the driving module (50) through the drawing, it is depicted as a driving system on one plane.

Specifically, the fixed pivot part (200) is a pivot structure configured to be rotatable while its position is fixed, and includes first to fourth pivots (210, 220, 230, 240) as illustrated. In this case, the first to fourth pivots (210, 220, 230, 240) may be fixed on the fixed body (11) as illustrated, but are not limited thereto, and may be fixed on other structures of the lower frame (10).

The first pivot (210) is positioned between the middle wheel (120) and the front wheel (110) and its position is fixed, and the second pivot (220) is also positioned between the middle wheel (120) and the front wheel (110) and its position is fixed, but can be positioned higher than the first pivot (210).

In addition, the third pivot (230) is positioned between the middle wheel (120) and the rear wheel (130) and its position is fixed, and the fourth pivot (240) is also positioned between the middle wheel (120) and the rear wheel (130) and its position is fixed, but can be positioned higher than the third pivot (230).

Each of the first to fourth pivots (210, 220, 230, 340) above is fixed in position and rotates according to the rotation or position change of the connecting links described below, thereby implementing the overall driving mechanism.

The front wheel link unit (300) is a link structure connected between the front wheel (110), the first pivot (210), the second pivot (220), and the coupling unit (500), and in particular, corresponds to a link structure that transmits an external force applied as the position of the front wheel (110) changes to the coupling unit (500).

Specifically, the front wheel link unit (300) includes a first front wheel link (310), a second front wheel link (320), and a front wheel damper (330).

The first front wheel link (310) includes a first sub-link (311) extending vertically in an upward direction (second direction, Y) from the center (111) of the front wheel (110), a second sub-link (312) extending horizontally in a horizontal direction (first direction, X) from the first sub-link (311), and a third sub-link (313) extending diagonally in a downward and rearward direction (in the opposite direction of the forward direction in which the mobility (1) proceeds, -X direction) from the second sub-link (312).

Accordingly, the first front wheel link (310) extends in a shape that is bent in a shape similar to the letter 'ㄱ' or 'ㅅ', and although it is described as being divided into first to third sub-links (311, 312, 313) for explanation, it may have a structure having a single integral shape. Of course, the angles and extension lengths formed by each of the sub-links in the first front wheel link (310) may be designed to vary.

However, since the first front wheel link (310) is extended in a shape that is bent in a shape similar to the letter 'ㄱ' or 'ㅅ', it can effectively absorb the impact initially against the external force applied according to the driving of the front wheel (110) and stably maintain the link structure.

Meanwhile, the end of the third sub-link (313) is connected to the first pivot (210), and thus the first front wheel link (310) can be driven to rotate as a whole around the first pivot (210). That is, when a predetermined external force is applied to the first front wheel link (310) or its posture is changed, the first front wheel link (310) rotates as a whole along with the rotation of the first pivot (210).

That is, the first pivot (210) and the third sub-link (313) are not connected to enable relative rotation, and the third sub-link (313) and the first pivot (210) are fixed to each other, and have a structure in which the third sub-link (313) rotates according to the rotation of the first pivot (210).

The second front wheel link (320) is a link connecting the first pivot (210) and the coupling unit (500), and as illustrated, includes a first sub-link (321) extending in a horizontal direction (first direction, X) and a second sub-link (322) that is bent in a shape similar to the letter 'ㄱ' on the coupling unit (500). However, the bent shape of the second sub-link (322) may vary depending on the detailed structure of the coupling unit (500), which will be described later.

The above second front wheel link (320) is also coupled and fixed to the first pivot (210), and has a structure in which the second front wheel link (320) also rotates according to the rotation of the first pivot (210).

Ultimately, when a predetermined external force is applied to the first front wheel link (310) or its posture is changed, the resulting rotational force is provided to the second front wheel link (320) through the first pivot (210), which ultimately induces a change in the posture of the second sub-link (322) on the coupling unit (500).

The front wheel damper (330) is connected between the third sub-link (313) of the first front wheel link (310) and the second pivot (220), and absorbs a predetermined external force provided according to the posture change or rotational drive of the first front wheel link (310).

The above front wheel damper (330) may be configured as a spring damper, for example, and may be designed to absorb a wide range of external forces by setting the spring constant in various ways in consideration of the external force to be absorbed, i.e., the driving environment.

Accordingly, the front wheel damper (330) can absorb a portion of the external force generated according to the driving environment of the front wheel (110), thereby improving the user's riding convenience and driving stability.

Furthermore, external force that is not absorbed by the front wheel damper (330) is provided to the coupling unit (500) through the rotation of the first pivot (210). At this time, the operation of the coupling unit (500) will be described later.

The above rear wheel link unit (400) is formed to have a substantially symmetrical link connection structure with the front wheel link unit (300) described above. That is, the front wheel link unit (300) may be connected to the front end with respect to the coupling unit (500) and the rear wheel link unit (400) may be connected to the rear end symmetrically. In this case, the rear wheel link unit (400) and the front wheel link unit (300) form an overall symmetry, and the lengths and connection angles of the detailed sub-links may be formed differently from each other.

Specifically, the rear wheel link unit (400) includes a first rear wheel link (410), a second rear wheel link (420), and a rear wheel damper (430).

The first rear wheel link (410) includes a first sub-link (411) extending vertically in an upward direction (second direction, Y) from the center (131) of the rear wheel (130), a second sub-link (412) extending horizontally in a horizontal direction (first direction, X) from the first sub-link (311), and a third sub-link (413) extending diagonally in a downward and forward direction (forward direction in which the mobility (1) proceeds, +X direction) from the second sub-link (412).

Accordingly, the first rear wheel link (410) extends in a shape that is bent in a shape similar to the letter 'ㄱ' or 'ㅅ', and although it is described as being divided into first to third sub-links (411, 412, 413) for explanation, it may have a structure having a single integral shape. Of course, the angle or extension length formed by each of the sub-links in the first rear wheel link (410) may be designed to be varied in various ways.

However, since the first rear wheel link (410) is extended in a shape that is bent in a shape similar to the letter 'ㄱ' or 'ㅅ', it can effectively absorb the impact initially against the external force applied according to the driving of the rear wheel (130) and stably maintain the link structure.

Meanwhile, the end of the third sub-link (413) is connected to the third pivot (230), and accordingly, the first rear wheel link (410) can be driven to rotate as a whole around the third pivot (230). That is, when a predetermined external force is applied to the first rear wheel link (410) or its posture changes, the first rear wheel link (410) rotates as a whole along with the rotation of the third pivot (230).

In this case, the connection structure of the third pivot (230) and the first rear wheel link (410) is substantially the same as the connection structure of the first pivot (210) and the first front wheel link (310) described above, and accordingly, the operating state is also substantially the same. Therefore, any duplicate description is omitted.

The second rear link (420) is a link connecting the third pivot (230) and the coupling unit (500), and as illustrated, includes a first sub-link (421) extending in a horizontal direction (first direction, X) and a second sub-link (422) that is bent in a shape similar to the letter 'ㄱ' on the coupling unit (500). However, the bent shape of the second sub-link (422) may vary depending on the detailed structure of the coupling unit (500), which will be described later.

The second rear wheel link (420) is also connected to and fixed to the third pivot (230), and has a structure in which the second rear wheel link (420) also rotates according to the rotation of the third pivot (230). This connection structure and operation structure are also substantially the same as the first pivot (210) and the second front wheel link (320) described above.

Ultimately, when a predetermined external force is applied to the first rear link (410) or its posture is changed, the resulting rotational force is provided to the second rear link (420) through the third pivot (230), which ultimately induces a change in the posture of the second sub-link (422) on the coupling unit (500).

The above rear wheel damper (430) is connected between the third sub-link (413) of the first rear wheel link (410) and the fourth pivot (240), and absorbs a predetermined external force provided according to the posture change or rotational drive of the first rear wheel link (410).

The above rear wheel damper (430) may be configured as a spring damper, for example, and may be designed to absorb a wide range of external forces by setting the spring constant in various ways in consideration of the external force to be absorbed, i.e., the driving environment.

Accordingly, the rear wheel damper (430) can absorb a portion of the external force generated according to the driving environment of the rear wheel (130), thereby improving the user's riding convenience and driving stability.

Furthermore, external force that is not absorbed by the rear wheel damper (430) is provided to the coupling unit (500) through the rotation of the third pivot (230). At this time, the operation of the coupling unit (500) will be described later.

As described above, the above coupling unit (500) has both the second sub-link (322) of the second front wheel link (320) and the second sub-link (422) of the second rear wheel link (420) positioned to form a predetermined coupling relationship with each other, and the above coupling unit (500) has a variable stiffness structure in which the stiffness is varied depending on the driving environment.

That is, the above-mentioned coupling unit (500) provides a space in which the second sub-link (322) of the second front wheel link (320) and the second sub-link (422) of the second rear wheel link (420) can freely move relative to each other in a normal driving environment, for example, thereby providing a user's riding convenience during normal driving with relatively small rigidity.

In contrast, the coupling unit (500) can provide relatively high rigidity and improve the ease of overcoming obstacles by coupling the second sub-link (322) of the second front wheel link (320) and the second sub-link (422) of the second rear wheel link (420) to each other so as to limit their mutual movement in a driving environment where a predetermined external force is generated, such as when overcoming an obstacle.

Below, various examples of the above-mentioned coupling unit (500) are described with reference to the drawings.

Figures 3a to 3e are schematic diagrams showing examples of the coupling unit of Figure 2.

First, referring to FIG. 3a, the coupling unit (500) may include a first coupling portion (510) and a second coupling portion (520).

In this case, the first connecting portion (510) is connected to the end of the second sub-link (322) of the second front wheel link (320) and may have a plate shape with a predetermined thickness. At this time, the shape of the plate is not limited to a square, triangle, circle, polygon, etc.

The second connecting portion (520) is connected to the end of the second sub-link (422) of the second rear link (420), has the same shape as the first connecting portion (510), and is arranged symmetrically to each other.

That is, the first and second connecting parts (510, 520) can be arranged to be spaced apart from each other by a predetermined distance (d) in the vertical direction (Y). At this time, the separation distance (d) can be variously preset.

Additionally, each of the first and second connecting portions (510, 520) may include an elastic body and may be made of a material such as rubber, for example.

As described above, the coupling unit (500) includes the first and second coupling portions (510, 520) that are spaced apart to have a preset separation distance (d), so that the first and second coupling portions (510, 520) can move freely within the range of the preset separation distance.

That is, the operation of the front wheel link unit (300) causing movement of the first coupling portion (510) and the operation of the rear wheel link unit (400) causing movement of the second coupling portion (520) are maintained free to move relatively within the range of the separation distance (d). This means that in a normal driving environment, when the front wheel (110) and the rear wheel (130) move within a preset range, it is possible to provide a comfortable ride to the user by maintaining relatively low rigidity.

However, if the first and second coupling parts (510, 520) are moved beyond the range of the preset separation distance, the first and second coupling parts (510, 520) are mechanically fixed to each other. That is, if the first and second coupling parts (510, 520) are spaced apart beyond the separation distance (d) or the separation distance (d) is narrowed so that the first and second coupling parts (510, 520) come into close contact with each other, the positions of the first and second coupling parts (510, 520) are mechanically fixed to each other, making relative movement impossible.

This means that in a driving environment where a certain level of external force is generated, such as when overcoming an obstacle, the interconnection relationship between the front wheel (110) and the rear wheel (130) is fixed, thereby providing relatively high rigidity and facilitating overcoming of the obstacle.

Also, referring to FIG. 3b, the coupling unit (501) may be composed of a single elastic body or damper. The second sub-link (322) of the second front wheel link (320) may be connected to an upper end of one side of the coupling unit (501), and the second sub-link (422) of the second rear wheel link (420) may be connected to a lower end of the other side of the coupling unit (501).

That is, the above-mentioned coupling unit (501) is an elastic body or damper having a block structure having a predetermined volume, and the second front wheel link (320) and the second rear wheel link (420) can be connected to each of both sides.

In this case, the above-mentioned coupling unit (501) is an elastic body or damper that absorbs a certain level of external force. If an external force exceeding the preset absorbable external force is input, it is difficult to absorb the excess external force, and ultimately, it functions as a mechanically solid structure.

Accordingly, in a normal driving environment, when the front wheel (110) and the rear wheel (130) move within a preset range, the external force provided to the coupling unit (501) is sufficiently absorbed by the coupling unit (501), so that the coupling unit (501) can maintain relatively low rigidity and provide a comfortable ride to the user.

In contrast, in a driving environment where an external force exceeding a certain level occurs, such as when overcoming an obstacle, the external force provided to the coupling unit (501) exceeds the absorbable range of the coupling unit (501), which ultimately fixes the interconnection relationship between the front wheel (110) and the rear wheel (130), thereby providing relatively high rigidity to facilitate overcoming the obstacle.

Also, referring to FIG. 3c, the coupling unit (502) includes a first coupling portion (530) and a second coupling portion (540), and the first and second coupling portions (530, 540) may have a bar or frame structure extending along the second direction (Y).

At this time, the second sub-link (322) of the second front wheel link (320) may be connected to the upper end of the first coupling portion (530), and the second sub-link (422) of the second rear wheel link (420) may be connected to the lower end of the second coupling portion (540).

In addition, as illustrated, the first coupling portion (530) has a bar or frame structure extending a predetermined length along the second direction (Y), and a coupling space (531) extending a predetermined length (d) along the extension direction of the first coupling portion (530) may be formed inside the first coupling portion (530).

In this case, the predetermined length (d) is preset and can be formed in various ways taking into account the driving environment of the mobility (1).

The second coupling portion (540) overlaps with the first coupling portion (530) and has a bar or frame structure extending a predetermined length along the second direction (Y), and a fastening portion (541) is formed on the upper side. The fastening portion (541) is a structure that moves on the coupling space (531), and the fastening portion (541) has a structure that can move freely within the range of the extension length (d) of the coupling space (531).

However, when the fastening portion (541) moves beyond the extension length (d) of the joining space (531), the movement of the fastening portion (541) is limited, and the positions of the first joining portion (530) and the second joining portion (540) are relatively fixed, so-called mechanically. That is, the fastening portion (541) does not move beyond the extension length (d) and its position is fixed on the joining space (531).

Accordingly, in a normal driving environment, when the front wheel (110) and the rear wheel (130) move within a preset range, the fastening portion (541) on the coupling unit (502) can move freely within the range of the coupling space (531), so that the coupling unit (502) can maintain relatively low rigidity and provide a comfortable ride to the user.

In contrast, in a driving environment where an external force exceeding a certain level is generated, such as when overcoming an obstacle, the fastening portion (541) is restricted from moving beyond the extended length (d) of the coupling space (531) on the coupling unit (502). That is, the external force provided to the coupling unit (502) is outside the absorbable range of the coupling unit (502), and the mechanical fixation between the fastening portion (541) and the coupling space (531) fixes the interconnection relationship between the front wheel (110) and the rear wheel (130), thereby providing relatively high rigidity to facilitate overcoming the obstacle.

Additionally, referring to FIG. 3d, the coupling unit (503) may include a first coupling portion (550) and a second coupling portion (560).

At this time, the first coupling portion (550) has a predetermined frame shape as illustrated and forms a coupling space (551) of a predetermined area therein. The first coupling portion (550) may have, for example, a rectangular frame shape with a cross-sectional area of a square as illustrated, but the shape is not limited and the area of the coupling space (551) may also be preset in various ways.

Additionally, the second sub-link (322) of the second front wheel link (320) is connected to one end of the first connecting portion (550).

The second coupling portion (560) can be freely moved within a predetermined coupling space (551) formed by the first coupling portion (550). That is, if the first coupling portion (550) extends a predetermined length (d) in the vertical direction (second direction), the second coupling portion (560) can be freely moved within the predetermined length range in the vertical direction, and likewise, can be freely moved within the predetermined length range in the horizontal direction (first direction).

In this case, the second sub-link (422) of the second rear link (420) is connected to the second connecting portion (560), and ultimately has a structure in which the fastening portion, which is the second connecting portion (560), is connected to the end of the second sub-link (422).

That is, the second coupling part (560) is configured in the form of a fastening part, and accordingly, when the fastening part (560) moves beyond a predetermined area range of the coupling space (551), the movement of the fastening part (560) is restricted, and the first coupling part (550) and the second coupling part (560) are mechanically fixed to each other so that their positions are fixed.

This means that the fastening portion (560) does not go beyond the range of the joining space (551) and its position is fixed on the joining space (551).

Accordingly, in a normal driving environment, when the front wheel (110) and the rear wheel (130) move within a preset range, the fastening portion (560) on the coupling unit (503) can move freely within the range of the coupling space (551), so that the coupling unit (503) can provide a comfortable ride to the user by maintaining relatively low rigidity.

In contrast, in a driving environment where an external force exceeding a certain level is generated, such as when overcoming an obstacle, the fastening portion (560) on the coupling unit (503) is restricted from moving beyond a preset area range of the coupling space (551). That is, the external force provided to the coupling unit (503) is outside the absorbable range of the coupling unit (503), and the mechanical fixation between the fastening portion (560) and the coupling space (551) fixes the interconnection relationship between the front wheel (110) and the rear wheel (130), thereby providing relatively high rigidity to facilitate overcoming the obstacle.

Additionally, referring to FIG. 3e, the coupling unit (504) may include a first coupling portion (570) and a second coupling portion (580).

At this time, the first connecting portion (570) has a predetermined circular frame shape as shown and is configured to be rotatable around a rotation center (571).

In addition, on the first coupling portion (570), a round coupling slot (572) of a predetermined length is formed in the circumferential direction based on the rotation center (571), and a coupling space (573) is formed inside the coupling slot (572).

In this case, the length of the coupling slot (572) formed in the first coupling portion (570) can be variously set, and can be variously set in consideration of the degree of relative movement with respect to the second coupling portion (580).

Additionally, the second sub-link (322) of the second front link (320) is connected to one side of the first connecting portion (570).

Furthermore, the second coupling portion (580) is moved within the coupling space (573) along the coupling slot (572), and can move freely within a certain length range along the round structure formed by the coupling slot (572).

In this case, the second sub-link (422) of the second rear link (420) is connected to the second connecting portion (560), and ultimately has a structure in which the fastening portion, which is the second connecting portion (580), is connected to the end of the second sub-link (422).

In particular, the first coupling part (570) rotates based on the rotation center (571), and as the first coupling part (570) rotates, the second coupling part (580) can freely change its position along the coupling slot (572) within the range of the position shown by the solid line and the position shown by the dotted line in FIG. 3e.

Accordingly, in a normal driving environment, when the front wheel (110) and the rear wheel (130) move within a preset range, the fastening portion (580) on the coupling unit (504) can move freely within the range of the coupling space (573), so that the coupling unit (504) can maintain relatively low rigidity and provide a comfortable ride to the user.

In contrast, in a driving environment where an external force exceeding a certain level is generated, such as when overcoming an obstacle, the fastening portion (580) on the coupling unit (504) is restricted from moving beyond a preset length of the coupling space (573). That is, the external force provided to the coupling unit (504) is outside the absorbable range of the coupling unit (504), and the mechanical fixation between the fastening portion (580) and the coupling space (573) fixes the interconnection relationship between the front wheel (110) and the rear wheel (130), thereby providing relatively high rigidity to facilitate overcoming the obstacle.

As described above, the above-mentioned connecting unit has various shapes and structures, and can provide a comfortable ride with relatively low rigidity in a normal driving environment, but in a driving environment where a certain level of external force is generated, such as when overcoming an obstacle, it can provide relatively high rigidity through fastening between connecting parts, etc., so as to more easily implement overcoming the obstacle.

Figure 4 is a schematic diagram illustrating a drive module according to another embodiment of the present invention.

The drive module (51) according to the present embodiment is substantially the same as the drive module (50) described with reference to FIGS. 1 to 3e, except for the link connection relationship of the fixed pivot part (201), the front link unit (600), and the rear link unit (700), so the same reference numbers are used for the same components and redundant descriptions are omitted.

Referring to Fig. 4, in the drive module (51) according to the present embodiment, first, the fixed pivot part (201) includes first to fourth pivots (211, 221, 231, 241). In this case, the first to fourth pivots (211, 221, 231, 241) may be fixed on the fixed body (11) as shown, but are not limited thereto, and may be fixed on other structures of the lower frame (10).

The first pivot (211) is positioned between the middle wheel (120) and the front wheel (110) and its position is fixed, and the second pivot (221) is also positioned between the middle wheel (120) and the front wheel (110) and its position is fixed, but can be positioned higher than the first pivot (211).

In addition, the third pivot (231) is positioned inside the middle wheel (120) and its position is fixed, and the fourth pivot (241) is positioned between the middle wheel (120) and the rear wheel (130) and its position is fixed, but can be positioned higher than the third pivot (231).

Each of the first to fourth pivots (211, 221, 231, 241) above is fixed in position and rotates according to the rotation or position change of the connecting links described later, thereby implementing the overall driving mechanism.

The front wheel link unit (600) is a link structure connected between the front wheel (110), the first pivot (211), the second pivot (221), and the coupling unit (500), and in particular, corresponds to a link structure that transmits an external force applied as the position of the front wheel (110) changes to the coupling unit (500).

Specifically, the front wheel link unit (600) includes a first front wheel link (610), a second front wheel link (630), and a front wheel damper (620).

The first front wheel link (610) includes a first sub-link (611) extending vertically in an upward direction (second direction, Y) from the center (111) of the front wheel (110), a second sub-link (612) extending horizontally in a horizontal direction (first direction, X) from the first sub-link (611), and a third sub-link (613) extending diagonally in a downward and rearward direction (in the opposite direction of the forward direction in which the mobility (1) proceeds, -X direction) from the second sub-link (612).

Accordingly, the first front wheel link (610) extends in a shape that is bent in a shape similar to the letter 'ㄱ' or 'ㅅ', and although it is described as being divided into first to third sub-links (611, 612, 613) for explanation, it may have a structure having a single integral shape. Of course, the angles and extension lengths formed by each of the sub-links in the first front wheel link (610) may be designed to vary.

However, since the first front wheel link (610) is extended in a shape that is bent in a shape similar to the letter 'ㄱ' or 'ㅅ', it can effectively absorb the impact initially against the external force applied according to the driving of the front wheel (110) and stably maintain the link structure.

The front wheel damper (620) is connected between the third sub-link (613) of the first front wheel link (610) and the second pivot (221), and absorbs a predetermined external force provided according to the posture change or rotational drive of the first front wheel link (610).

The above front wheel damper (620) may be configured as a spring damper, for example, and may be designed to absorb a wide range of external forces by setting the spring constant in various ways in consideration of the external force to be absorbed, i.e., the driving environment.

Accordingly, the front wheel damper (620) can absorb a portion of the external force generated according to the driving environment of the front wheel (110), thereby improving the user's riding convenience and driving stability.

Furthermore, external force that is not absorbed by the front wheel damper (620) is provided to the coupling unit (500) through the rotation of the second pivot (221). At this time, the operation of the coupling unit (500) is the same as that described above in FIGS. 3a to 3e, so a duplicate description is omitted.

The second front wheel link (630) is a link connecting the second pivot (221) and the coupling unit (500), and as illustrated, includes a first sub-link (631) extending in a horizontal direction (first direction, X) and a second sub-link (632) that is bent in a shape similar to the letter 'ㄱ' on the coupling unit (500). However, the bent shape of the second sub-link (632) may vary depending on the detailed structure of the coupling unit (500), which will be described later.

The second front wheel link (630) is coupled and fixed to the second pivot (221), and has a structure in which the second front wheel link (630) also rotates according to the rotation of the second pivot (221).

Ultimately, when a predetermined external force is applied to the first front wheel link (610) or its posture is changed, the resulting rotational force is provided to the second front wheel link (630) through the second pivot (220), which ultimately induces a change in the posture of the second sub-link (632) on the coupling unit (500).

The above rear wheel link unit (700) includes a first rear wheel link (710), a second rear wheel link (720), and a rear wheel damper (730).

The first rear wheel link (710) includes a first sub-link (711) extending vertically in an upward direction (second direction, Y) from the center (131) of the rear wheel (130), and a second sub-link (712) extending diagonally in an upward and forward direction (forward direction in which the mobility (1) proceeds, +X direction) from the first sub-link (611).

Accordingly, the first rear wheel link (710) extends in a shape that is bent in a shape similar to the letter 'ㄱ' or 'ㅅ', and although it is described separately as first and second sub-links (711, 712) for explanation, it may have a structure having a single integral shape. Of course, the angle or extension length formed by each of the sub-links in the first rear wheel link (710) may be designed to vary.

However, since the first rear wheel link (710) is extended in a shape that is bent in a shape similar to the letter 'ㄱ' or 'ㅅ', it can effectively absorb the impact initially against the external force applied according to the driving of the rear wheel (130) and stably maintain the link structure.

Meanwhile, the end of the second sub-link (712) is connected to the fourth pivot (241), and thus the first rear link (710) can be driven to rotate as a whole around the fourth pivot (241). That is, when a predetermined external force is applied to the first rear link (710) or its posture changes, the first rear link (710) rotates as a whole along with the rotation of the fourth pivot (241).

In this case, the connection between the fourth pivot (240) and the first rear wheel link (710) may not be a connection that allows relative rotation, and may be a connection relationship in which the first rear wheel link (710) also rotates integrally according to the rotation of the fourth pivot (241).

The second rear link (720) is a link connecting the fourth pivot (241) and the coupling unit (500), and as shown, can extend in the horizontal direction (first direction, X).

The second rear wheel link (720) is also connected to and fixed to the fourth pivot (241), and has a structure in which the second rear wheel link (720) also rotates according to the rotation of the fourth pivot (241).

Ultimately, when a predetermined external force is applied to the first rear wheel link (710) or its posture is changed, the resulting rotational force is provided to the second rear wheel link (720) through the fourth pivot (241), which ultimately induces a change in the posture of the coupling unit (500).

However, the rear wheel damper (730) is connected between the second rear wheel link (720) and the third pivot (231), and absorbs a predetermined external force provided according to the posture change or rotational drive of the second rear wheel link (720).

The above rear wheel damper (730) may be configured as a spring damper, for example, and may be designed to absorb a wide range of external forces by setting the spring constant in various ways in consideration of the external force to be absorbed, i.e., the driving environment.

Accordingly, the rear wheel damper (730) can absorb a portion of the external force generated according to the driving environment of the rear wheel (130), thereby improving the user's riding convenience and driving stability.

Furthermore, external force that cannot be absorbed by the rear wheel damper (730) is provided to the coupling unit (500) as described above.

Meanwhile, in the case of the above-mentioned coupling unit (500), it is connected to the second sub-link (632) of the second front link (630) and the second rear link (720), and the specific structure of the above-mentioned coupling unit (500) and the external force absorption structure according to it are the same as those described with reference to FIGS. 3a and 3e.

Accordingly, redundant descriptions are omitted, and in this embodiment, the coupling unit (500) has a variable stiffness structure, so that it can maintain riding comfort during normal driving as well as easily overcome obstacles.

Figure 5 is a schematic diagram illustrating a drive module according to another embodiment of the present invention.

The drive module (52) according to the present embodiment further includes a center wheel link unit (800) connected to the center wheel (120), and is substantially the same as the drive module (50) described with reference to FIGS. 1 and 2 except that the structure of the coupling unit (505) is different. Therefore, the same reference numbers are used for the same components, and redundant descriptions are omitted.

Referring to FIG. 5, in the drive module (52) according to the present embodiment, the middle wheel link unit (800) is a link structure connected between the middle wheel (120), the first pivot (212), the fifth pivot (252), and the coupling unit (505).

Meanwhile, in the present embodiment, the fixed pivot part (202) is substantially the same as the fixed pivot part (200) described with reference to FIGS. 1 and 2, except that the fifth pivot (252) is additionally provided on the upper portion of the coupling unit (505) and the center wheel (120). That is, the first to fourth pivots (210, 220, 230, 240) in FIGS. 1 and 2 are the same as the first to fourth pivots (212, 222, 232, 242) in the present embodiment.

The above-mentioned middle wheel link unit (800) includes a first middle wheel link (810), a second middle wheel link (820), and a middle wheel damper (830).

The first center link (810) extends diagonally downward from the first pivot (212) and then bends to extend horizontally in the rearward (i.e., negative first direction) direction and is connected to the rotation center (121) of the center link (120).

In this case, the first middle link (810) and the first pivot (212) are connected in a fixed state to each other, and the first middle link (810) also rotates according to the rotation of the first pivot (212).

The second middle wheel link (820) extends horizontally in the rearward (negative first direction) direction from the rotation center (121) of the middle wheel (120), and the end of the second middle wheel link (820) is positioned at the coupling unit (500).

At this time, the second middle wheel link (820) is connected to the first middle wheel link (810) through the rotation center (121) of the middle wheel (120), and although its movement is not restricted to the rotation of the middle wheel (120), it may have a structure in which it is integrally connected to the first middle wheel link (810).

Accordingly, when the first middle wheel link (810) rotates according to the rotation of the first pivot (212), the second middle wheel link (820) can rotate based on the rotation center (121) of the middle wheel (120). That is, the first middle wheel link (810) and the second middle wheel link (820) can be configured as a frame structure that rotates based on the rotation center (121) of the middle wheel (120).

The above-mentioned middle wheel damper (830) extends in the vertical direction (i.e., the second direction) between the fifth pivot (252) and the second middle wheel link (820).

The above-mentioned center damper (830) may also be configured as, for example, a spring damper, and may be designed to absorb a wide range of external forces by setting the spring constant in various ways in consideration of the external force to be absorbed, i.e., the driving environment.

Accordingly, the middle wheel damper (830) can absorb a portion of the external force generated according to the driving environment of the middle wheel (120), thereby improving the user's riding comfort and driving stability. Furthermore, the external force that is not absorbed by the middle wheel damper (830) is provided to the coupling unit (500) as described above.

Meanwhile, the front wheel link unit (300) and the rear wheel link unit (400) have the same link connection structure as described with reference to FIGS. 1 and 2.

The structure of the above-described coupling unit (505) according to this connection relationship is explained with reference to the drawings described below.

Figure 6 is a schematic diagram illustrating the coupling unit of Figure 5.

That is, referring to FIG. 6, the coupling unit (505) couples the second sub-link (322) of the second front wheel link (320), the second sub-link (422) of the second rear wheel link (420), and the second middle wheel link (820) to each other, and includes a first coupling portion (590), a second coupling portion (595), and a third coupling portion (596).

The first coupling portion (590) is connected to the second sub-link (322) of the second front wheel link (320), and has a frame shape with a predetermined width, and a first coupling space (591) is formed at the upper portion and a second coupling space (592) is formed at the lower portion. That is, the first and second coupling spaces (591, 592) are formed to be spaced apart from each other in the vertical direction (i.e., the second direction).

Additionally, the first and second coupling spaces (591, 592) may have the same area.

Through the drawing, the first connecting portion (590) has an overall rectangular shape, and a pair of first and second connecting spaces (591, 592) of rectangular shapes are formed inside, but it can have a frame structure of various shapes other than the rectangular shape, and accordingly, the connecting spaces formed inside can also have various shapes.

Furthermore, the area of the first and second coupling spaces (591, 592) can also be varied to various areas in consideration of the external force applied depending on the driving environment.

Meanwhile, the second coupling portion (595) may be a predetermined fastening portion that extends from the second sub-link (422) of the second rear wheel link (420) and is positioned inside the first coupling space (591), and the third coupling portion (596) may be a predetermined fastening portion that extends from the second middle wheel link (820) and is positioned inside the second coupling space (592).

Accordingly, the position of the second coupling portion (595) can be freely changed within the first coupling space (591) within the range of the area formed by the first coupling space (591), and similarly, the position of the third coupling portion (596) can be freely changed within the second coupling space (592) within the range of the area formed by the second coupling space (592).

However, when the second coupling portion (595) moves beyond the area range of the first coupling space (591), the second coupling portion (595) can be fixed in position by being fastened on the first coupling space (591). That is, when the second coupling portion (595) moves beyond the area range of the first coupling space (591), it is fixed on the first coupling space (591) and its position is restricted from further movement.

Likewise, when the third coupling portion (596) moves beyond the area range of the second coupling space (592), the third coupling portion (596) can be fixed in position by being fastened onto the second coupling space (592). That is, when the third coupling portion (596) moves beyond the area range of the second coupling space (592), it is fixed onto the second coupling space (592) and its position is restricted from further movement.

Accordingly, in a normal driving environment, when the front wheel (110), the middle wheel (120), and the rear wheel (130) move within a preset range, the first and second fastening parts (595, 596) on the coupling unit (505) can move freely within the range of the first and second coupling spaces (591, 592), respectively, so that the coupling unit (505) can provide a comfortable ride to the user by maintaining relatively low rigidity.

In contrast, in a driving environment where an external force exceeding a certain level is generated, such as when overcoming an obstacle, the first and second fastening portions (595, 596) on the coupling unit (505) are restricted from moving beyond the preset range of the first and second coupling spaces (591, 592), respectively. That is, the external force provided to the coupling unit (505) is outside the absorbable range of the coupling unit (505), and the mutual connection relationship of the front wheel (110), the middle wheel (120), and the rear wheel (130) is fixed by the respective mechanical fixation between the first and second fastening portions (595, 596) and the first and second coupling spaces (591, 592), thereby providing relatively high rigidity to realize ease of overcoming an obstacle.

Meanwhile, referring to FIGS. 5 and 6, in the connection structure of the front wheel, middle wheel, and rear wheel link units (300, 400, 800) and the connection structure of the coupling portion (505), when the first pivot (212) rotates clockwise, the middle wheel (120) can be driven so that the ground contact force is relatively improved.

Likewise, when the third pivot (232) rotates counterclockwise, the center wheel (120) can be driven relatively to improve ground contact.

That is, the center wheel (120) moves in the opposite direction to the overall rotation direction of the front wheel link unit (300) or the overall rotation direction of the rear wheel link unit (400), so that it can have higher ground contact force, especially in the process of overcoming an obstacle, and thus it is possible to overcome an obstacle with higher driving force.

According to the embodiments of the present invention as described above, a coupling unit is included that connects the front and rear wheels to each other, or connects the front, middle, and rear wheels to each other, and the rigidity of the coupling unit is varied according to the driving environment, thereby providing optimal driving stability and user riding convenience according to various driving environments.

In this case, the coupling unit can provide a space in which each link unit connected to the front and rear wheels, or the front, middle, and rear wheels, can freely move relative to each other in a normal driving environment, thereby providing a user's riding convenience during normal driving with relatively little rigidity. In contrast, in a driving environment where a certain external force is generated, such as when overcoming an obstacle, the coupling unit can provide relatively great rigidity by connecting the link units to each other to limit the mutual movement between the link units, thereby improving the ease of overcoming an obstacle.

The variable stiffness structure of the above-mentioned coupling unit can be implemented through various structures, thereby providing an optimal stiffness variable suspension structure according to various design adaptability and driving environments.

In particular, in the case of a combined unit in which the front, middle, and rear wheels are all connected, by forming multiple movable spaces for the link units, a free movable space for each link unit can be formed, thereby providing excellent riding comfort with relatively small rigidity.

In addition, in the case of a combination unit in which the front, middle, and rear wheels are all connected, the middle wheel link unit is designed to rotate in the opposite direction to the rotational direction of the front wheel link unit and the rear wheel link unit, thereby further improving the grip of the middle wheel in driving environments such as overcoming obstacles.

Furthermore, link units extending between the front, middle, and rear wheels and the connecting unit are designed to be optimally connected with the minimum number of links, thereby simplifying the design while improving the user's riding convenience, grip, and driving stability.

Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

1: Mobility 50, 51, 52: Drive module
100: Wheel unit 200, 201, 202: Fixed pivot unit
300, 600: Front link unit 310, 610: First front link
320, 630: Second front link 330, 620: Front damper
400, 700: Rear link unit 410, 710: First rear link
420, 720: Second rear link 430: Rear damper
500, 501, 502, 503, 504, 505: Combination Units
800: Middle link unit 810: First middle link
820: Second middle link 830: Third middle link
510, 530, 550, 570, 590: First joint
520, 540, 560, 580, 595: Second joint
596: Third joint

Claims (17)

A wheel unit including a center wheel to which driving force is provided, and front and rear wheels positioned respectively in front and behind the center wheel;
A fixed pivot portion including a plurality of pivots that rotate while being fixed to a fixed body;
A front wheel link unit connected from the front wheel to the fixed body through the fixed pivot portion;
A rear wheel link unit connected from the rear wheel to the fixed body through the fixed pivot portion; and
The end of the front wheel link unit and the end of the rear wheel link unit are connected, and a connecting unit is included that is controlled so that the rigidity varies depending on the driving environment.
The above-mentioned coupling unit is a drive module characterized in that, in a normal driving environment, the ends of the front link unit and the rear link unit can move freely within a predetermined space to provide relatively small rigidity, and in a driving environment where an external force is generated, the ends of the front link unit and the rear link unit are coupled to each other to restrict mutual movement, thereby providing relatively large rigidity. delete In the first paragraph, the coupling unit,
A first connecting portion connected to the end of the front wheel link unit; and
A drive module characterized by including a second connecting portion connected to the end of the rear wheel link unit. In the third paragraph,
The first and second connecting parts are arranged to be spaced apart from each other by a predetermined distance,
A drive module, characterized in that each of the first and second connecting parts includes an elastic body. In the fourth paragraph, the first and second connecting parts,
In normal driving conditions, they are placed at a certain distance apart,
A drive module characterized by being in close contact with each other in a driving environment where external force is generated. In the third paragraph,
The above first joint extends in one direction and forms a joint space having a predetermined length inside,
A drive module characterized in that the second coupling portion extends in the same direction as the first coupling portion and includes a fastening portion positioned inside the coupling space. In the third paragraph,
The above first joint has a frame shape and forms a joint space having a predetermined area inside,
A drive module characterized in that the second coupling portion is a fastening portion located inside the coupling space. In the third paragraph,
The above first joint has a frame shape and forms a joint slot extending in an arc shape inside,
A drive module characterized in that the second coupling portion is a fastening portion located inside the coupling slot. In any one of the 6th to 8th clauses, the fastening part,
In a normal driving environment, it is freely movable inside the first joint,
A driving module characterized in that it is fixed on the first connecting portion in a driving environment where an external force is generated. In the first paragraph, the coupling unit,
A drive module characterized in that the end of the front wheel link unit and the end of the rear wheel link unit include elastic bodies or dampers connected to both sides. In the first paragraph, the front wheel link unit,
A first front wheel link connected between the front wheel and the first pivot of the fixed pivot part;
a second front wheel link connected between the first pivot and the coupling unit; and
A drive module characterized by including a front wheel damper connected between the first front wheel link and the second pivot of the fixed pivot part. In the 11th paragraph, the rear link unit,
A first rear wheel link connected between the rear wheel and the third pivot of the fixed pivot part;
A second rear link connected between the third pivot and the coupling unit; and
A drive module characterized by including a rear wheel damper connected between the first rear wheel link and the fourth pivot of the fixed pivot part. In Article 12,
It further includes a middle wheel link unit connected between the middle wheel, the fixed body and the coupling unit,
The above-mentioned middle link unit is,
A first center wheel link connected between the center wheel and the first pivot;
A second center wheel link connected between the center wheel and the coupling unit; and
A drive module further comprising a center wheel damper connected between the above-mentioned coupling unit and the fifth pivot of the above-mentioned fixed pivot portion. In the 13th paragraph, the coupling unit,
A first connecting portion connected to the end of the front wheel link unit;
A second connecting portion connected to the end of the rear wheel link unit; and
A drive module characterized by including a third connecting portion connected to the above-mentioned middle wheel link unit. In Article 14,
The above first connecting portion has a frame shape and forms first and second connecting spaces spaced apart from each other and having a predetermined area,
The above second connecting portion is a fastening portion located inside the first connecting space,
A drive module characterized in that the third connecting portion is a fastening portion located inside the second connecting space. In the 15th paragraph, the fastening part,
In a normal driving environment, it is possible to move freely in the first coupling space and the second coupling space,
A driving module characterized in that it is fixed on the first connecting portion in a driving environment where an external force is generated. The driving module of paragraph 1;
A lower frame in which the above driving module is provided; and
A mobility device including a boarding section for a user to ride on the upper part of the above-mentioned lower frame.